FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Koponen, K Myers, MS Ritola, O Huuskonen, SE Lindstrom-Seppa, P AF Koponen, K Myers, MS Ritola, O Huuskonen, SE Lindstrom-Seppa, P TI Histopathology of feral fish from a PCB-Contaminated freshwater lake SO AMBIO LA English DT Article ID TROUT ONCORHYNCHUS-MYKISS; POLYCHLORINATED-BIPHENYLS PCBS; RAINBOW-TROUT; SALMO-GAIRDNERI; EXPOSURE; LIVER; KIDNEY; HYDROCARBONS; BIOMARKERS; CONGENERS AB The purpose of this study was to evaluate the potential toxic effects of chronic sublethal polychlorinated biphenyl (PCB) exposure on feral fish, using histopathology as an endpoint. Histopathological study of bream (Abramis brama) and asp (Aspius aspius) living in a PCB-polluted freshwater lake revealed abnormal cellular changes in the renal corpuscle of both species. Dilation of glomerular capillaries (DGC), mesangial edema (ME), an adhesion between visceral and parietal layers of Bowman's capsule (ABC), and filling of Bowman's space (FBS), were highly prevalent features in lake fish. The prevalence of each of these lesions was significantly lower, or totally absent in fish caught from reference locations. Cellular alterations in liver, gill, gonads, spleen, and intestine were all linked to seasonal changes. The results suggest that some of the observed histopathological changes in renal glomeruli, particularly DGC and ME, could possibly indicate a prolonged chemical stress caused by PCBs and related compounds. It is also possible that chronic PCB exposure may have suppressed and weakened the immune systems of exposed fish making them more vulnerable to secondary parasitic infections. C1 Univ Kuopio, Dept Physiol, FIN-70211 Kuopio, Finland. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Koponen, K (reprint author), Univ Kuopio, Dept Physiol, POB 1627, FIN-70211 Kuopio, Finland. EM kari.koponen@pp6.inet.fi; mark.s.myers@noaa.gov; ossi.ritola@uku.fi; sirpa.huuskonen@kolumbus.fi; pirjo.lindstromseppa@uku.fi NR 41 TC 21 Z9 22 U1 2 U2 10 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0044-7447 J9 AMBIO JI Ambio PD MAY PY 2001 VL 30 IS 3 BP 122 EP 126 DI 10.1639/0044-7447(2001)030[0122:HOFFFA]2.0.CO;2 PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 440WT UT WOS:000169200200002 PM 11436658 ER PT J AU Sherman, K Duda, AM AF Sherman, K Duda, AM TI Toward ecosystem-based recovery of marine biomass yield SO AMBIO LA English DT Article ID ECOLOGY; MANAGEMENT; WATER C1 NOAA, Natl Marine Fisheries Serv, USDOC, NE Fisheries Sci Ctr,Narragansett Lab, Narragansett, RI 02882 USA. GEF Secretariat, Washington, DC 20433 USA. RP Sherman, K (reprint author), NOAA, Natl Marine Fisheries Serv, USDOC, NE Fisheries Sci Ctr,Narragansett Lab, 28 Tarzwell Dr, Narragansett, RI 02882 USA. NR 25 TC 5 Z9 5 U1 0 U2 1 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0044-7447 J9 AMBIO JI Ambio PD MAY PY 2001 VL 30 IS 3 BP 168 EP 169 DI 10.1639/0044-7447(2001)030[0168:TEBROM]2.0.CO;2 PG 2 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 440WT UT WOS:000169200200011 ER PT J AU Levin, PS Schiewe, MH AF Levin, PS Schiewe, MH TI Preserving salmon biodiversity SO AMERICAN SCIENTIST LA English DT Article ID PACIFIC SALMON; POPULATIONS; EVOLUTION; WILD C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Levin, PS (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 13 TC 28 Z9 28 U1 0 U2 3 PU SIGMA XI-SCI RES SOC PI RES TRIANGLE PK PA PO BOX 13975, RES TRIANGLE PK, NC 27709 USA SN 0003-0996 J9 AM SCI JI Am. Scientist PD MAY-JUN PY 2001 VL 89 IS 3 BP 220 EP 227 DI 10.1511/2001.22.734 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 422RH UT WOS:000168132700017 ER PT J AU Jiang, Y Wang, PC Locascio, LE Lee, CS AF Jiang, Y Wang, PC Locascio, LE Lee, CS TI Integrated plastic microftuidic devices with ESI-MS for drug screening and residue analysis SO ANALYTICAL CHEMISTRY LA English DT Article ID ULTRAFILTRATION-MASS-SPECTROMETRY; CAPILLARY ELECTROPHORESIS; PULSED ULTRAFILTRATION; MICROFLUIDIC NETWORKS; DNA; MICRODIALYSIS; SYSTEMS; CHIPS; FABRICATION; SEPARATIONS AB For this work, two different plastic microfluidic devices are designed and fabricated for applications in throughput residue analysis of food contaminants and drug screening of small-molecule libraries. Microfluidic networks on copolyester and poly(dimethylsiloxane) substrates are fabricated by silicon template imprinting and capillary molding techniques. The first device is developed to perform affinity capture, concentration, and direct identification of targeted compounds using electrospray ionization mass spectrometry. Poly(vinylidene fluoride) membranes sandwiched between the imprinted copolyester microchannels in an integrated platform preside continuous affinity dialysis and concentration of a reaction mix-lure containing aflatoxin B-1 antibody and aflatoxins. The second microfluidic device is composed of microchannels on the poly(dimethylsiloxane) substrates, The device is designed to perform miniaturized ultrafiltration of affinity complexes of phenobarbital antibody and barbiturates, including the sequential loading, washing, and dissociation steps, These microfabricated devices not only significantly reduce dead volume and sample consumption but also increase the detection sensitivity by at least 1 - 2 orders of magnitude over those reported previously. Improvements in detection sensitivity are attributed to analyte preconcentration during the affinity purification step, limited analyte dilution in the microdialysis junction, minimal sample loss, and the amenability of ESI-MS to nanoscale sample floss rates. C1 Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Lee, CS (reprint author), Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. NR 35 TC 102 Z9 103 U1 2 U2 28 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 MAY 1 PY 2001 VL 73 IS 9 BP 2048 EP 2053 DI 10.1021/ac001474j PG 6 WC Chemistry, Analytical SC Chemistry GA 429LZ UT WOS:000168519800026 PM 11354489 ER PT J AU McKnight, ME Vorburger, TV Marx, E Nadal, ME Barnes, PY Galler, MA AF McKnight, ME Vorburger, TV Marx, E Nadal, ME Barnes, PY Galler, MA TI Measurements and predictions of light scattering by clear coatings SO APPLIED OPTICS LA English DT Article ID SINUSOIDAL SURFACES; INTERFEROMETRY; PROFILER AB Comparisons are made between calculated and measured angle-resolved light-scattering distributions from clear dielectric isotropic epoxy coatings over a range of rms roughness conditions, resulting in strongly specular scattering to diffuse scattering characteristics. Calculated distributions are derived from topography measurements performed with interferometric microscopes. Two methods of calculation are used. One determines the intensity of scattered light waves with a phase integral in the Kirchhoff approximation. The other is based on the reflection of light rays by locally flat surfaces. The angle-resolved scattering distributions for the coatings are measured with the spectral trifunction automated reference reflectometer (STARR) developed by the National Institute of Standards and Technology. Comparisons between measured and calculated results are shown for three surfaces with rms roughness values of approximately 3, 150, and 800 nm for an angle of incidence of 20 degrees. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP McKnight, ME (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM mary.mcknight@nist.gov NR 24 TC 20 Z9 20 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD MAY 1 PY 2001 VL 40 IS 13 BP 2159 EP 2168 DI 10.1364/AO.40.002159 PG 10 WC Optics SC Optics GA 427HM UT WOS:000168398800014 PM 18357223 ER PT J AU Jackson, M Telles, EM Allen, MD Evenson, KM AF Jackson, M Telles, EM Allen, MD Evenson, KM TI Short-wavelength far-infrared laser cavity yielding new laser emissions in CD3OH SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID FREQUENCY MEASUREMENTS; PUMPED CD3OH; LINES; METHANOL; ASSIGNMENTS; SPECTROSCOPY AB A significantly improved far-infrared laser has been used to generate optically pumped laser emissions from 26 to 150 mum for CD3OH. Using an X-V-pumping geometry, several new laser emissions have been found for CD3OH. In addition, an increase in power, by factors from 10 to 1000, fur many of the previously known shorter-wavelength laser lines, below 100 mum, has been observed. Frequency measurements fur several lines have also been performed and have been reported to a fractional uncertainty up to +/-2 x 10(-7), permitting the spectroscopic assignment of the laser transition. One of the frequency-measured lines, 44.256 mum observed using the 10R34 pump, has confirmed the assignment of the previously reported FIR emission (n, K; J) = (1,7; 20) --> (0, 8; 20)A in the ground vibrational state. C1 Univ Wisconsin, Dept Phys, La Crosse, WI 54601 USA. Univ Estadual Campinas, Inst Phys Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Jackson, M (reprint author), Univ Wisconsin, Dept Phys, La Crosse, WI 54601 USA. RI Inst. of Physics, Gleb Wataghin/A-9780-2017 NR 23 TC 23 Z9 23 U1 0 U2 7 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD MAY PY 2001 VL 72 IS 7 BP 815 EP 818 PG 4 WC Optics; Physics, Applied SC Optics; Physics GA 436JY UT WOS:000168933800004 ER PT J AU Hwang, H Fisher, SW Landrum, PF AF Hwang, H Fisher, SW Landrum, PF TI Identifying body residues of HCBP associated with 10-d mortality and partial life cycle effects in the midge, Chironomus riparius SO AQUATIC TOXICOLOGY LA English DT Article DE body residues; HCBP; life cycle test; midges; chronic endpoints ID SEDIMENT; TOXICITY; LETHAL; BIOASSAYS; TIME; PENTACHLOROPHENOL; BIOCONCENTRATION; BIOAVAILABILITY; TOXICOKINETICS; CONTAMINANTS AB The relationship between the body residue of 2,2',4,4',5,5'-hexachlorobiphenyl (HCBP) and its effects, including 10-d mortality and chronic sublethal effects on the midge, Chironomus riparius, are examined in a partial life cycle assessment. The alga, Chlorella vulgaris, was loaded with C-14-labeled HCBP and fed to midges as the method for delivery of the toxicant. In a 10-d bioassay, median lethal body residue (LR50) was 0.57 (95% CI: 0.49-0.66) mmol/kg. In the partial life cycle test, midges were fed a mixture of C-12- and C-14-HCBP-laden algae and exposed in four separate tests to assess the different developmental stages representing 2nd to 3rd instar, 2nd to 4th, 2nd to pupa, and 2nd to adult stages. A variety of sublethal endpoints were monitored, including developmental time within a stadium, body concentration at the end of each stadium, body weight, and fecundity (the number of ova) for the female pupae and adults. Overall, midge body concentrations of HCBP increased with increasing exposure concentration. Body weight was not significantly affected by HCBP except during the 4th instar. Body residue also increased with each successive stadium. Developmental time increased significantly with increasing body concentration in 2nd to 4th, 2nd to pupa, and 2nd to adult tests, while there was no statistical significance in developmental time for the 2nd to 3rd instar test. The number of ova decreased significantly in adults with increasing body concentration of HCBP, with an average of 345 ova in controls, 289 ova at 0.028 mmol/kg of HCBP, and 258 ova at 0.250 mmol/kg. These data, which, relate chronic endpoints to body residues, suggest that sublethal endpoints in invertebrates are useful for defining sublethal hazards of PCBs. These data also suggest that ecological consequences may result from relatively low body burdens of PCBs. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Ohio State Univ, Environm Sci Grad Program, Columbus, OH 43210 USA. Ohio State Univ, Dept Entomol, Columbus, OH 43210 USA. NOAA, Great Lakes Res Lab, Ann Arbor, MI 48105 USA. RP Fisher, SW (reprint author), Ohio State Univ, Environm Sci Grad Program, 1735 Neil Ave 103, Columbus, OH 43210 USA. NR 46 TC 26 Z9 28 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-445X J9 AQUAT TOXICOL JI Aquat. Toxicol. PD MAY PY 2001 VL 52 IS 3-4 BP 251 EP 267 DI 10.1016/S0166-445X(00)00142-9 PG 17 WC Marine & Freshwater Biology; Toxicology SC Marine & Freshwater Biology; Toxicology GA 424AG UT WOS:000168209500007 PM 11239686 ER PT J AU Rose, WL French, BL Reichert, WL Faisal, M AF Rose, WL French, BL Reichert, WL Faisal, M TI Persistence of benzo[a]pyrene-DNA adducts in hematopoietic tissues and blood of the mummichog, Fundulus heteroclitus SO AQUATIC TOXICOLOGY LA English DT Article; Proceedings Paper CT 10th International Symposium on Pollutant Responses in Marine Organisms (PRIMO 10) CY APR 25-29, 1999 CL COLL WILLIAM & MARY, WILLIAMSBURG, VIRGINIA HO COLL WILLIAM & MARY DE DNA adducts; hematopoietic tissues; Fundulus heteroclitus; benzo(a)pyrene ID POLYCYCLIC AROMATIC-HYDROCARBONS; PLAICE PLEURONECTES-PLATESSA; CREOSOTE-CONTAMINATED SITE; CARP CYPRINUS-CARPIO; DNA-ADDUCTS; IMMUNOHISTOCHEMICAL LOCALIZATION; PSEUDOPLEURONECTES-AMERICANUS; LEIOSTOMUS-XANTHURUS; IMMUNE ORGANS; TELEOST FISH AB The formation and persistence of benzo[a]pyrene (B[a]P)-DNA adducts were investigated in blood, liver and two hematopoietic tissues (anterior kidney and spleen) of the mummichog (Fundulus heteroclitus). Fish were injected with a single, sublethal dose of B[a]P (12 mg/kg body weight) and sampled from 8 to 96 days post-injection. P-32-Postlabeling analysis and storage phosphor imaging were used to resolve and quantify hydrophobic DNA adducts. One major DNA adduct was present in each of the examined tissues at all sampling times. This adduct had similar chromatographic characteristics to those of the adduct standard, 7R,8S,9S-trihydroxy-10S-(N-2-deoxyguanosyl-3'-phosphate)-7,8,9,10-tetrahydro-benzo[a]pyrene (B[a]PDE-dG). Minor DNA adduct spots, representing less than 2% of the total DNA adducts, were observed in some liver, anterior kidney and spleen samples for up to 32 days post-injection. The B[a]P-DNA adducts reached maximal levels at 32 days post-injection and persisted for at least 96 days in all examined tissues. B[a]P-DNA adduct levels were significantly higher in the liver and anterior kidney than in the spleen from 16 to 96 days (P < 0.001), although liver and anterior kidney DNA adduct levels were not significantly different at any time. This is the first controlled study to demonstrate the formation and persistence of B[a]P-DNA adducts in hematopoietic tissues and blood of fishes exposed to the prototypical polycyclic aromatic hydrocarbon, B[a]P. Although persistent DNA adducts are generally recognized as potential initiators of carcinogenic processes, adducts in these vital tissues may also lead to disruption of physiological functions such defense mechanisms and hematopoiesis. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. RP Faisal, M (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. NR 54 TC 7 Z9 7 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-445X J9 AQUAT TOXICOL JI Aquat. Toxicol. PD MAY PY 2001 VL 52 IS 3-4 BP 319 EP 328 DI 10.1016/S0166-445X(00)00125-9 PG 10 WC Marine & Freshwater Biology; Toxicology SC Marine & Freshwater Biology; Toxicology GA 424AG UT WOS:000168209500012 PM 11239691 ER PT J AU Kling, R Schnabel, R Griesmann, U AF Kling, R Schnabel, R Griesmann, U TI Accurate lifetimes and absolute transition rates for ultraviolet transitions from 3d(5)((4)G) 4p and 3d(5)(4P) 4p levels in MN II SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE atomic data; methods : laboratory; ultraviolet : general ID SPECTROMETER RESPONSE CALIBRATION; LASER-INDUCED-FLUORESCENCE; VACUUM-ULTRAVIOLET; BRANCHING RATIOS; ARGON; BEAM AB A recently developed, laser-induced fluorescence technique was used to measure the lifetimes of 14 3d(5)((4)G)4p and 3d(5)(P-4)4p levels in the Mn+ ion. Branching fractions for electric dipole transitions from these levels were measured with a vacuum ultraviolet Fourier transform spectrometer, using a hollow-cathode lamp and a Penning discharge source. Based on these new measurements, absolute electric dipole transition rates for about 170 spectral lines in the ultraviolet and vacuum ultraviolet were determined. The uncertainty of the transition rates is less than 5% for the strong transitions. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Hannover, Inst Atom & Mol Phys, Abt Plasmaphys, D-30167 Hannover, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kling, R (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 20 TC 19 Z9 19 U1 1 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD MAY PY 2001 VL 134 IS 1 BP 173 EP 178 DI 10.1086/320366 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 432TG UT WOS:000168711300010 ER PT J AU Wang, T Cheung, VTF Lam, KS Kok, GL Harris, JM AF Wang, T Cheung, VTF Lam, KS Kok, GL Harris, JM TI The characteristics of ozone and related compounds in the boundary layer of the South China coast: temporal and vertical variations during autumn season SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE ozone; CO; NOx; SO2; coastal Hong Kong; subtropical Asia ID HONG-KONG; CHEMICAL CHARACTERISTICS; TROPOSPHERIC OZONE; AIR-QUALITY; RURAL SITE; PEM-WEST; NOY; PACIFIC; POLLUTANTS; POLLUTION AB We present measurements of several trace gases made at a subtropical coastal site in Hong Kong in October and November 1997. The gases include O-3, CO, SO2, and NOx. The surface measurement data are compared with those from an aircraft study [Kok et al. J. Geophys. Res. 102(D15)(1997) 19043-19057], and a subset of the latter is used to show the vertical distribution of the trace gases in the boundary layer. During the study period. averaged concentrations at the surface site for O-3, CO, NOx, and SO2 were 50, 298, 2.75, and 1.65 ppbv, respectively. Their atmospheric abundance and diurnal pattern are similar to those found in the "polluted" rural areas in North America. The measured trace gases are fairly well mixed in the coastal boundary layer in the: warm South China region. Large variability is indicated from the data. Examination of 10-day, isentropic back trajectories shows that the: measured trace gases are influenced by maritime air masses, outflow of pollution-laden continental air, and the mixing of the two. The trajectories capture the contrasting chemical Features of the large-scale air masses impacting on the study area. CO, NOx and SO2 all show higher concentrations in the strong outflow of continental air. as expected, than those in the marine category. Compared with previously reported values for the western Pacific, the much higher levels found in the marine trajectories in our study suggest the impacts of regional and,or sub-regional emissions on the measured trace gases at the study site. The presence of abundant O-3 and other chemically active trace gases in the autumn season. coupled with high solar radiation and warm weather, suggests that the South China Sea is a photochemically active region important for studying the chemical transformation of pollutants emitted from the Asian continent. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Hong Kong Polytech Univ, Dept Civil & Struct Engn, Reg Air Monitoring & Res Grp, Hong Kong, Hong Kong, Peoples R China. Cathedral Consulting, Boulder, CO 80303 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Wang, T (reprint author), Hong Kong Polytech Univ, Dept Civil & Struct Engn, Reg Air Monitoring & Res Grp, Hong Kong, Hong Kong, Peoples R China. RI WANG, Tao/B-9919-2014 OI WANG, Tao/0000-0002-4765-9377 NR 30 TC 41 Z9 45 U1 1 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAY PY 2001 VL 35 IS 15 BP 2735 EP 2746 DI 10.1016/S1352-2310(00)00411-8 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 438TT UT WOS:000169070900013 ER PT J AU Kneller, LR Edwards, AM Nordgren, CE Blasie, JK Berk, NF Krueger, S Majkrzak, CF AF Kneller, LR Edwards, AM Nordgren, CE Blasie, JK Berk, NF Krueger, S Majkrzak, CF TI Hydration state of single cytochrome c monolayers on soft interfaces via neutron interferometry SO BIOPHYSICAL JOURNAL LA English DT Article ID X-RAY INTERFEROMETRY; VECTORIALLY ORIENTED MONOLAYERS; PROFILE STRUCTURES; MULTILAYER FILMS; DIFFRACTION; SURFACE; HOLOGRAPHY; PHASE AB Yeast cytochrome c (YCC) can be covalently tethered to, and thereby vectorially oriented on, the soft surface of a mixed endgroup (e.g., -CH3/-SH = 6:1, or -OH/-SH = 6:1) organic self-assembled monolayer (SAM) chemisorbed on the surface of a silicon substrate utilizing a disulfide linkage between its unique surface cysteine residue and a thiol endgroup. Neutron reflectivities from such monolayers of YCC on Fe/Si or Fe/Au/Si multilayer substrates with H2O versus D2O hydrating the protein monolayer at 88% relative humidity for the nonpolar SAM (-CH3/-SH = 6:1 mixed endgroups) surface and 81% for the uncharged-polar SAM (-OH/-SH = 6:1mixed endgroups) surface were collected on the NG1 reflectometer at NIST. These data were analyzed using a new interferometric phasing method employing the neutron scattering contrast between the Si and Fe layers in a single reference multilayer structure and a constrained refinement approach utilizing the finite extent of the gradient of the profile structures for the systems. This provided the water distribution profiles for the two tethered protein monolayers consistent with their electron density profile determined previously via x-ray interferometry (Chupa et al., 1994). C1 Univ Penn, Dept Chem, Philadelphia, PA 19104 USA. Univ Penn, Dept Phys, Philadelphia, PA 19104 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Blasie, JK (reprint author), Univ Penn, Dept Chem, 231 S 34th St, Philadelphia, PA 19104 USA. NR 19 TC 14 Z9 15 U1 1 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 MAY PY 2001 VL 80 IS 5 BP 2248 EP 2261 PG 14 WC Biophysics SC Biophysics GA 428WZ UT WOS:000168485800021 PM 11325727 ER PT J AU Frenzen, P Vogel, CA AF Frenzen, P Vogel, CA TI Further studies of atmospheric turbulence in layers near the surface: Scaling the TKE budget above the roughness sublayer SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE atmospheric turbulence; cup anemometer overspeeding; dimensionless shear function (or phi(m)); roughness sublayer; turbulence dissipation deficit; turbulence scaling; turbulent kinetic energy (or TKE) budget ID KANSAS MAST INFLUENCE; VON KARMAN CONSTANT; KINETIC-ENERGY; APPARENT RANGE; BOUNDARY-LAYER; REVALUATION; MAGNITUDE; PROFILES; STRESS; FLOW AB The second of two experimental studies of the TKE budget conducted on sites of different roughness is described, and results are compared. The first took place within a shallow layer above a small field of mostly bare, cultivated soil; the second was carried out above a roughness sublayer of significant depth on an extensive plain of tall dry grass. Budget terms observed in the second study were scaled with a modified u(*) which compensated for effects of an unusually large stress gradient and ensured that the phi (m) functions would be collinear. By showing that the modification becomes negligible in smaller gradients, it is demonstrated that in normal conditions, budgets observed above significant roughness sublayers should be normalized by scaling in terms of the unreduced Reynolds stress at the sublayer's upper surface. This procedure is shown to be consistent with the expectation that TKE budgets in layers near the surface all scale in fundamentally the same way. Other findings include: (1) the fact that most phi (m) functions previously reported are not quite collinear is attributed to a type of overspeeding known to affect three-cup anemometers; (2) revised phi (m) functions, collinear and largely free of the effects of overspeeding, are determined from a well-established characteristic of the linear phi (m) relation for the stable case; (3) data that define collinear phi (m) functions can also be represented with single hyperbolic curves; (4) dissipation is found to be 10 to 15% too small to balance total TKE production in unstable and neutral conditions and to decrease with increasing z/L in the stable regime; and (5) new relations for phi (epsilon) based on the observed behaviour of the dissipation deficit provide an improved closure for the set of equations that express the budget terms as functions of phi (m) and z/L. C1 NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. RP 263 Kala Hts Dr, Port Townsend, WA 98368 USA. NR 40 TC 21 Z9 24 U1 1 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0006-8314 EI 1573-1472 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD MAY PY 2001 VL 99 IS 2 BP 173 EP 206 DI 10.1023/A:1018956931957 PG 34 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 416ZB UT WOS:000167809500001 ER PT J AU Vasiloff, SV AF Vasiloff, SV TI Improving tornado warnings with the Federal Aviation Administration's Terminal Doppler Weather Radar SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID WSR-88D AB The potential role of the Federal Aviation Administration's Terminal Doppler Weather Radar (TDWR) to supplement the Weather Surveillance Radar-1988 Doppler (WSR-88D) for tornado detection is discussed. Compared to the WSR-88D, the TDWR has a narrower beam, lower scan angles, and faster update rates. The 11 August 1999 Salt Lake City, Utah, tornado is used as an illustration of the utility of the TDWR. The Salt Lake City TDWR was much closer to the tornado than the WSR-88D and the WSR-88D was 750 m higher than the TDWR. Because the tornado developed rapidly upward from a surface convergence line, the TDWR detected the formation earlier than the WSR-88D. Also, the vortex signatures associated with the tornado were much better defined by the TDWR. The enhanced spatial and temporal coverage provided by the TDWR network is shown. A significant improvement in tornado detection, as well as other low-altitude phenomena, would be gained. However, ground clutter and signal attenuation can degrade coverage. Ongoing efforts by the National Weather Service to incorporate TDWR data into operations are described. C1 Natl Severe Storms Lab, Norman, OK 73069 USA. RP Vasiloff, SV (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 17 TC 20 Z9 20 U1 2 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 MAY PY 2001 VL 82 IS 5 BP 861 EP 874 DI 10.1175/1520-0477(2001)082<0861:ITWWTF>2.3.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 428WY UT WOS:000168485700001 ER PT J AU Hatfield, EMC Hanlon, RT Forsythe, JW Grist, EPM AF Hatfield, EMC Hanlon, RT Forsythe, JW Grist, EPM TI Laboratory testing of a growth hypothesis for juvenile squid Loligo pealeii (Cephalopoda : Loliginidae) SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID SEXUAL-MATURATION; FINNED SQUID; CEPHALOPODA; TEMPERATURE; AGE; POPULATIONS; OTOLITHS; BEHAVIOR; MEXICO; GULF AB Growth modeling in squid has been hampered by a paucity of raw growth data on live individuals. We reared wild juvenile squid Loligo pealeii, for up to 97 days post capture, to determine the form of growth and to test the hypothesis that a 5 degreesC difference in temperature would significantly affect growth rates. Precapture growth rates (the instantaneous relative growth rate or percent increase in body mass per day (IRGR)) of 8-11% were estimated using statolith age data. Laboratory growth rates over a maximum of 97 experimental days fell into two phases in which most L. pealeii grew exponentially, albeit at a slower rate in phase 2. In both phases, the values of IRGR were significantly higher for L. pealeii reared at 20 degreesC than for those reared at 15 degreesC, being respectively, 4.36 and 2.69 in phase 1 and 2.57 and 1.63 in phase 2. This study provides strong evidence of phase-specific temperature sensitivity in squid growth. The IRGR values obtained were used to simulate the growth of squid hatched in nature from May to September in a simple predictive model. The growth simulations indicated that, by the end of phase-1 growth, squid hatched in June and July were two and three times the weight, respectively, at the same age, as squid hatched in May, owing to their exposure to warmer temperatures. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. Marine Biol Lab, Woods Hole, MA 02543 USA. Inst Marine Biomed, Natl Resource Ctr Cephalopods, Galveston, TX 77555 USA. Univ London, Sch Biol Sci, Egham TW20 0EX, Surrey, England. RP Hatfield, EMC (reprint author), Fisheries Res Serv, Marine Lab Aberdeen, POB 101,Victoria Rd, Aberdeen AB11 9DB, Scotland. EM e.hatfield@marlab.ac.uk RI Hanlon, Roger/Q-8687-2016 OI Hanlon, Roger/0000-0003-0004-5674 NR 41 TC 35 Z9 37 U1 0 U2 2 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD MAY PY 2001 VL 58 IS 5 BP 845 EP 857 DI 10.1139/cjfas-58-5-845 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 429QH UT WOS:000168528100002 ER PT J AU Takagi, S Liao, H Chow, LC AF Takagi, S Liao, H Chow, LC TI Effect of a low-fluoride-content. two-component rinse on fluoride uptake and on de- and remineralization of enamel lesions: An in vitro study SO CARIES RESEARCH LA English DT Article DE fluoride rinse; fluoride; enamel; mineralization; calcium fluoride; sodiumhexafluorosilicate; in vitro pH cyclic model ID PROGRESSION INVITRO; 2-SOLUTION RINSE; PLAQUE FLUID; IN-VITRO; MOUTHRINSE; DENTIFRICE; CALCIUM; SALIVA; CARIES; NAF AB The effect of calcium (Ca) concentrations and added ethanol on fluoride (F) depositions by experimental two-component rinses, each consisting of a Ca-containing and an F-containing component, was evaluated in an in vitro system. Among the tested rinses, a 3 mmol/l F two-component rinse with 200 mmol/l Ca and 10% v/v ethanol was found to produce the greatest F deposition relative to the F concentration in the rinse. Specifically, this rinse produced an F deposition that was about 7 times greater than a conventional 13.2-mmol/l sodium fluoride (NaF) rinse. In a second experiment, an in vitro pH cycling model was used to evaluate the potential anti-caries effects of 4 rinses: (1) placebo rinse (no F), (2) 13.2-mmol/l NaF rinse, (3) 52.6-mmol/l NaF rinse, and (4) the 3-mmol/l F two-component rinse in a 7-day in vitro pH cycling model. The changes in lesion mineral contents, delta(DeltaZ), as assessed by quantitative microradiographic measurements, were as follows [mean +/- standard deviation, n = 10]: (1) 72.5 +/- 10.2 mum, (2) 43.4 +/- 5.6 mum, (3) 17.3 +/- 10.2 mum and (4) 45.3 +/-5.2 mum. These results showed that the 3-mmol/l F two-component rinse produced the same (p >0.05) protection against demineralization as did the 13.2-mmol/l NaF rinse which had 4 times the fluoride content. The results suggest that it is possible to formulate an effective low-F two-component rinse. Copyright (C) 2001 S. KargerAG, Basel. C1 Natl Inst Stand & Technol, Div Polymers, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. WESTAT Corp, Rockville, MD 20850 USA. RP Takagi, S (reprint author), Natl Inst Stand & Technol, Div Polymers, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [DE05354] NR 30 TC 9 Z9 10 U1 0 U2 0 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 0008-6568 J9 CARIES RES JI Caries Res. PD MAY-JUN PY 2001 VL 35 IS 3 BP 223 EP 228 DI 10.1159/000047460 PG 6 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 438RX UT WOS:000169069000011 PM 11385204 ER PT J AU Ho, DL Briber, RM Glinka, CJ AF Ho, DL Briber, RM Glinka, CJ TI Characterization of organically modified clays using scattering and microscopy techniques SO CHEMISTRY OF MATERIALS LA English DT Article ID LAYERED-SILICATE NANOCOMPOSITES; ANGLE NEUTRON-SCATTERING; POLYMER; DYNAMICS; MIXTURES; COLLOIDS AB Understanding the structure of organophilic clays and the interaction between clay platelets dispersed in organic solvents is important for characterizing nanocomposites formed by organophilic clays and polymers. To understand and optimize potential processing conditions, organically modified montmorillonite clays were dispersed in a number of organic solvents covering a range of solubility parameters and characterized using small-angle neutron scattering and wide-angle X-ray scattering techniques. The organic modifier was dimethyl dihydrogenated tallow ammonium. Both as-received (unextracted) and purified (extracted) organically modified clays were studied. The scattering profiles and dispersion behavior in organic solvents of the dry powder of unextracted and of extracted dimethyl dihydrogenated tallow montmorillonite are significantly different, confirming that the organic modifiers are present in excess in the unextracted material as reported by the industrial provider. The scattering data show that both unextracted and extracted organically modified clay platelets were fully exfoliated in chloroform while the platelets retain their lamellar structure and swell to a similar extent in benzene, toluene, and p-xylene, but the extracted material has a stronger tendency to gel. The scattering profiles indicate that the swollen tactoids of extracted material are thinner, and therefore more numerous, which may account for the bulk suspension behavior. The extracted clay dispersion exhibited a concentration dependence on the scattering for all the organic solvents studied except chloroform while the unextracted clay dispersion did not. Neither the extracted nor the unextracted dispersions exhibited any temperature dependence on the scattering. The thickness of unmodified montmorillonite platelets was found to be 9.9 Angstrom while that of organically modified montmorillonite platelets was determined to be 24.3 Angstrom using wide-angle X-ray scattering. The lateral size of organically modified montmorillonite platelets was observed to be in the range of 0.4-1.0 mum using atomic force microscopy. C1 Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Ho, DL (reprint author), Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RI Briber, Robert/A-3588-2012 OI Briber, Robert/0000-0002-8358-5942 NR 28 TC 83 Z9 83 U1 1 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD MAY PY 2001 VL 13 IS 5 BP 1923 EP 1931 DI 10.1021/cm0008617 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 435DB UT WOS:000168861200072 ER PT J AU Saigal, A Fuller, ER AF Saigal, A Fuller, ER TI Analysis of stresses in aluminum-silicon alloys SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article AB Two-phase aluminum-silicon-based alloys are widely used for premium quality castings for aerospace and automotive applications. While it is clear that silicon improves fluidity in the molten state, providing excellent castability to the alloy, and increases the tensile strength of the alloy, much needs to be done to improve the understanding of the structure-property relationships in castings. This paper deals with the application of a microstructural finite element method and the OOF program to study the effect of size and shape of silicon particles on the stresses in the silicon particles and the aluminum matrix. The highest stress in the matrix increases with increasing particle size for a given volume fraction of silicon particles. Therefore, the yield strength of a microstructure containing coarse particles would be lower than one containing fine particles. Once the silicon particles with large aspect ratios crack or the microstructure containing large silicon particles yield. the effective stiffness of the aluminum matrix decreases which significantly increases the average stress in the silicon particles and the highest stresses in both the silicon particles and the aluminum matrix. This indicates that once the matrix yields, the potential for particle cracking increases dramatically. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Tufts Univ, Dept Mech Engn, Medford, MA 02155 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Saigal, A (reprint author), Tufts Univ, Dept Mech Engn, Medford, MA 02155 USA. NR 16 TC 34 Z9 34 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD MAY PY 2001 VL 21 IS 1 BP 149 EP 158 DI 10.1016/S0927-0256(00)00224-X PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 426WG UT WOS:000168371000015 ER PT J AU Langer, SA Fuller, E Carter, WC AF Langer, SA Fuller, E Carter, WC TI OOF: An image-based finite-element analysis of material microstructures SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article ID SIMULATION; CERAMICS AB Determining a material's macroscopic properties given its microscopic structure is of fundamental importance to materials science, The authors describe two public-domain programs that jointly predict macroscopic behavior. The programs start from an image of the microstructure and end with results from finite-element calculations. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. MIT, Cambridge, MA 02139 USA. RP Langer, SA (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RI Carter, W/K-2406-2012 NR 14 TC 142 Z9 142 U1 0 U2 11 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD MAY-JUN PY 2001 VL 3 IS 3 BP 15 EP 23 DI 10.1109/5992.919261 PG 9 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 424CA UT WOS:000168213500008 ER PT J AU Lovejoy, NR Collette, BB AF Lovejoy, NR Collette, BB TI Phylogenetic relationships of new world needlefishes (Teleostei : Belonidae) and the biogeography of transitions between marine and freshwater habitats SO COPEIA LA English DT Article ID MOLECULAR SYSTEMATICS; CENTRAL-AMERICA; SOUTH-AMERICA; EVOLUTION; FISHES; STINGRAYS; LIMITS; GENES; RAG2; DNA AB The New World clade of needlefishes (Belonidae) includes species distributed along the Pacific and Atlantic coasts of the Americas and in freshwater basins of Central and South America. Phylogenetic relationships among 13 species of the group were assessed based on data from two nuclear genes (RAG2 and Tmo-4C4), two mitochondrial genes (cytochrome b and 16S rRNA), and a small suite of morphological characters. In general, there was concordance between separate analyses of nuclear and mitochondrial characters, and RAG2 was found to be a particularly useful gene for phylogeny reconstruction. Morphology supported an alternative phylogenetic pattern, but this was probably a result of the small number of characters and the lack of a thorough anatomical survey, The total evidence hypothesis divides the group into two major clades, In one, Pseudotylosurus from freshwater in South America is most closely related to a pair of Strongylura species from the western and eastern Atlantic; in the other, Potamorrhaphis and Belonion from South American freshwater are related to a clade of Strongylura from marine and freshwater habitats of the eastern Pacific and western Atlantic. Optimization of habitat on the total evidence tree, combined with paleogeographic data, suggests that four independent entries into freshwater have taken place-one in Central America, and three in South America. C1 Natl Museum Nat Hist, Natl Marine Fisheries Serv, Systemat Lab, Washington, DC 20560 USA. Cornell Univ, Ecol & Systemat Sect, Ithaca, NY 14853 USA. RP Lovejoy, NR (reprint author), Univ Calif Berkeley, Museum Vertebrate Zool, 3101 Valley Life Sci Bldg 3160, Berkeley, CA 94720 USA. EM lovejoy7@uclink4.berkeley.edu NR 63 TC 64 Z9 68 U1 3 U2 7 PU AMER SOC ICHTHYOLOGISTS & HERPETOLOGISTS PI MIAMI PA MAUREEN DONNELLY, SECRETARY FLORIDA INT UNIV BIOLOGICAL SCIENCES, 11200 SW 8TH STREET, MIAMI, FL 33199 USA SN 0045-8511 EI 1938-5110 J9 COPEIA JI Copeia PD MAY 1 PY 2001 IS 2 BP 324 EP 338 DI 10.1643/0045-8511(2001)001[0324:PRONWN]2.0.CO;2 PG 15 WC Zoology SC Zoology GA 432AJ UT WOS:000168663700002 ER PT J AU Kiffney, PM Richardson, JS AF Kiffney, PM Richardson, JS TI Interactions among nutrients, periphyton, and invertebrate and vertebrate (Ascaphus truei) grazers in experimental channels SO COPEIA LA English DT Article ID STREAM PERIPHYTON; BRITISH-COLUMBIA; PHOSPHORUS ENRICHMENT; RESPONSES; LIMITATION; HERBIVORES; COMMUNITY; GROWTH; LIGHT; RIVER AB Objectives of this study were to determine whether (1) stream algal biomass was nutrient limited, (2) stream herbivores could reduce algal biomass at different levels of productivity, and (3) a large vertebrate herbivore (Ascaphus truei) affected the abundance of insect grazers under different nutrient supply regimes. To address these objectives, we conducted a 2 x 2 factorial experiment to examine the effects of varying phosphate supply on periphyton biomass, insect grazers, and a tadpole grazer in 12 streamside experimental channels in southwestern Canada. We manipulated presence of tailed frog tadpoles (A. truei Stejneger) and varied nutrient levels using nutrient-diffusing pellets. We monitored periphyton biomass as ash-free dry mass (AFDM), insect grazer abundance, dissolved nutrients (NO3 - N and PO4 - P) in water, and tadpole growth rates over 38 days. Dissolved nitrate and phosphate concentrations were temporally variable, and there were no statistical differences among treatments, but dissolved phosphate levels were 1.7 times greater in nutrient-enriched channels (3.2 mug L-1) than in unenriched channels (1.7 mug L (1)). Periphyton AFDM was significantly higher in channels with added nutrients, as was abundance of insect grazers, primarily Chironomidae and Ephemeroptera. Tadpoles in channels with nutrients had growth rates approximately four times higher than tadpoles in controls. Insect grazer abundance in channels with and without added nutrients was lower in the presence of tadpoles, and this reduction was greater in channels with nutrients, In contrast to other studies that have examined the impact of vertebrate herbivores on periphyton, tadpoles had no measurable effect on periphyton biomass, These data indicate periphyton and grazers were resource limited, as added nutrients increased periphyton biomass, as well as abundance (insect grazers) and biomass (tailed frog tadpoles) of herbivores. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. Univ British Columbia, Dept Forest Sci, Vancouver, BC V6T 1Z4, Canada. British Columbia Minist Environm, Wildlife Branch, Vancouver, BC V6T 1Z4, Canada. RP Kiffney, PM (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. RI Richardson, John/G-1513-2012 OI Richardson, John/0000-0001-8135-7447 NR 41 TC 32 Z9 34 U1 0 U2 20 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS PI CHARLESTON PA UNIV CHARLESTON, GRICE MARINE LABORATORY, 205 FORT JOHNSON RD, CHARLESTON, SC 29412 USA SN 0045-8511 J9 COPEIA JI Copeia PD MAY 1 PY 2001 IS 2 BP 422 EP 429 DI 10.1643/0045-8511(2001)001[0422:IANPAI]2.0.CO;2 PG 8 WC Zoology SC Zoology GA 432AJ UT WOS:000168663700011 ER PT J AU Govoni, JJ Hoss, DE AF Govoni, JJ Hoss, DE TI Comparison of the Development and Function of the Swimbladder of Brevoortia tyrannus (Clupeidae) and Leiostomus xanthurus (Sciaenidae) SO COPEIA LA English DT Article ID LARVAL ATLANTIC MENHADEN; SWIM BLADDER INFLATION; SALMO-GAIRDNERI; NORTH-CAROLINA; GULF-MENHADEN; BUOYANCY; FISH; SYSTEM; GROWTH; DEFLATION AB The swimbladders of physostomous Brevoorlia tyrannus (Atlantic menhaden) and physoclistous Leiostomus xanthurus (spot) develop as a simple evagination of the larval foregut, The swimbladder of L, xanthurus develops earlier (at yolk and oil globule depletion when larvae are two days posthatch and similar to2 mm notochord length) than it does in B. tyrannus (well after yolk and oil depletion when larvae are 12 days and similar to8 mm), The Larvae of each species initially inflate the swimbladder by ascending to the surface and forcing atmospheric gas through a pneumatic duct into the swimbladder lumen, Larval B, tyrannus modulate swimbladder volume and buoyancy within a diel cycle by inflation with atmospheric gas passed through a persistent pneumatic duct and deflation by diffusion through the swimbladder wall along with expulsion through the anus and mouth. This capacity of swimbladder volume modulation and buoyancy compensation corresponds with the average vertical distribution of larvae in the sea, where larval B. tyrannus occupy the upper water column. The pneumatic duct of L. xanthurus atrophies after 20 days and has no discernable lumen after 40 days, the beginning of metamorphosis when larvae are similar to7 mm standard length, The mucosal epithelium of the swimbladder of L, xanthurus acquires cytological characteristics of adult gas-gland tissue soon after initial inflation when larvae gain the capability of gas secretion. A plexiform rete mirabile does not form until metamorphosis, The swimbladder of larval L. xanthurus functions by providing neutral buoyancy with low amplitude diel depth changes in swimbladder volume. In the sea, larval L, xanthurus occupy primarily mid- and deep depths. C1 NOAA, Natl Ocean Serv, Natl Ctr Coastal Ocean Sci, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. RP NOAA, Natl Ocean Serv, Natl Ctr Coastal Ocean Sci, Ctr Coastal Fisheries & Habitat Res, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. EM jeff.govoni@noaa.gov NR 67 TC 23 Z9 24 U1 1 U2 6 PU AMER SOC ICHTHYOLOGISTS & HERPETOLOGISTS PI MIAMI PA MAUREEN DONNELLY, SECRETARY FLORIDA INT UNIV BIOLOGICAL SCIENCES, 11200 SW 8TH STREET, MIAMI, FL 33199 USA SN 0045-8511 EI 1938-5110 J9 COPEIA JI Copeia PD MAY 1 PY 2001 IS 2 BP 430 EP 442 DI 10.1643/0045-8511(2001)001[0430:COTDAF]2.0.CO;2 PG 13 WC Zoology SC Zoology GA 432AJ UT WOS:000168663700012 ER PT J AU Greenough, G McGeehin, M Bernard, SM Trtanj, J Riad, J Engelberg, D AF Greenough, G McGeehin, M Bernard, SM Trtanj, J Riad, J Engelberg, D TI The potential impacts of climate variability and change on health impacts of extreme weather events in the United States SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE climate change; extreme weather events; flooding; global warming; natural disasters; storms ID PUERTO-RICO; RISK-FACTORS; INJURIES; DEATHS; PRECIPITATION; DISASTER; TORNADO; DISEASE; FREQUENCY; TRENDS AB Extreme weather events such as precipitation extremes and severe storms cause hundreds of deaths and injuries annually in the United States. Climate change? may alter the frequency, timing, intensity, and duration of these events. Increases in heavy precipitation have occurred over the past century. Future climate scenarios show likely increases in the frequency of extreme precipitation events, including precipitation during hurricanes, raising the risk of floods. Frequencies of tornadoes and hurricanes cannot reliably be projected. Injury and death are the direct health impacts most often associated with natural disasters. Secondary effects, mediated by changes in ecologic systems and public health infrastructure, also occur. The health impacts of extreme weather events hinge on the vulnerabilities and recovery capacities of the natural environment and the local population. Relevant variables include building codes, warning systems, disaster policies, evacuation plans, and relief efforts. There are many federal, state, and local government agencies and nongovernmental organizations involved in planning for and responding to natural disasters in the United States. Future research on health impacts of extreme weather events should focus on improving climate models to project any trends in regional extreme events and as a result improve public health preparedness and mitigation. Epidemiologic studies of health effects beyond the direct impacts of disaster will provide a more accurate measure of the full health impacts and will assist in planning and resource allocation. C1 US Ctr Dis Control & Prevent, Natl Ctr Environm Hlth, Div Environm Hazards & Hlth Effects, CDC, Atlanta, GA 30333 USA. Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Environm Hlth Sci, Baltimore, MD USA. Natl Ocean & Atmospher Adm, Off Global Programs, Silver Spring, MD USA. Univ Delaware, Disaster Res Ctr, Newark, DE USA. RP McGeehin, M (reprint author), US Ctr Dis Control & Prevent, Natl Ctr Environm Hlth, Div Environm Hazards & Hlth Effects, CDC, Atlanta, GA 30333 USA. NR 95 TC 96 Z9 104 U1 12 U2 74 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD MAY PY 2001 VL 109 SU 2 BP 191 EP 198 DI 10.2307/3435009 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 434PF UT WOS:000168824500004 PM 11359686 ER PT J AU Kimm-Brinson, KL Moeller, PDR Barbier, M Glasgow, H Burkholder, JM Ramsdell, JS AF Kimm-Brinson, KL Moeller, PDR Barbier, M Glasgow, H Burkholder, JM Ramsdell, JS TI Identification of a P2X7 receptor in GH(4)C(1) rat pituitary cells: A potential target for a bioactive substance produced by Pfiesteria piscicida SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE c-fos; GH(4)C(1); P2X7; Pfiesteria; pituitary; purinergic; toxin ID EXTRACELLULAR ATP; MICROGLIAL CELLS; P2X(7) RECEPTOR; PLASMA-MEMBRANE; ESTUARINE FISH; P2Z RECEPTOR; DINOFLAGELLATE; MACROPHAGES; EXPRESSION; EXPOSURE AB We examined the pharmacologic activity of a putative toxin (pPfTx) produced by Pfesteria piscicida by characterizing the signaling pathways that induce the c-fos luciferase construct in GH(4)C(1) rat pituitary cells. Adenosine-5 ' -triphosphate (ATP) was determined to increase and, at higher concentrations, decrease luciferase activity in GH(4)C(1) rat pituitary cells that stably express c-fos luciferase. The inhibition of luciferase results from cytotoxicity, characteristic of the putative P. piscicida toxin (pPfTx). The actions of both pPfTx and ATP to induce c-fos luciferase were inhibited by the purinogenic receptor antagonist pyridoxalphosphate-6-azophenyl-2 ' ,4 ' -disulfonic acid (PPADS). Further characterization of a P2X receptor on the GH(4)C(1) cell was determined by the analog selectivity of P2X agonists. The P2X1/P2X3 agonist alpha,beta -methylene ATP (alpha,beta -MeATP) failed to increase or decrease c-fos luciferase. However, the P2X7 agonist 2 ' ,3 '-(4-benzoyl)benzoyl ATP (BzATP), which had a predominant cytotoxic effect, was more potent than ATP. Immunoblot analysis of GH(4)C(1) cell membranes confirmed the presence of a 70-kDa protein that was immunoreactive to an antibody directed against the carboxy-terminal domain unique to the P2X7 receptor. The P2X7 irreversible antagonist oxidized-ATP (oxATP) inhibited the action of ATP, BzATP, and pPfTx. These findings indicate that GH(4)C(1) cells express purinogenic receptors with selectivity consistent with the P2X7 subtype and that this receptor pathway mediates the induction of the c-fos luciferase reporter gene by ATP and the putative Pfiesteria toxin. C1 NOAA, Coastal Res Branch,Ctr Coastal Environm Hlth & Bi, Natl Ocean Serv, Marine Biotoxins Program, Charleston, SC 29412 USA. N Carolina State Univ, Dept Bot, Raleigh, NC 27695 USA. RP Ramsdell, JS (reprint author), NOAA, Coastal Res Branch,Ctr Coastal Environm Hlth & Bi, Natl Ocean Serv, Marine Biotoxins Program, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 38 TC 33 Z9 34 U1 1 U2 2 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD MAY PY 2001 VL 109 IS 5 BP 457 EP 462 DI 10.2307/3454703 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 438YA UT WOS:000169080800024 PM 11401756 ER PT J AU Paulson, AJ Gendron, JF AF Paulson, AJ Gendron, JF TI Partitioning of copper at concentrations below the marine water quality criteria SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE copper; partitioning; water quality criteria; adsorption; Cu-64 ID CONDITIONAL STABILITY-CONSTANTS; PHASE LIQUID-CHROMATOGRAPHY; ORGANIC-COMPLEXES; SPECIATION; SEAWATER; EXTRACTION; PACIFIC; SEA AB Partioning of Cu between the aqueous and particulate phases and among their components was examined in six ambient Paget Sound, Washington State, USA, samples (6-10 nM Cu). Most of the particulate Cu (4-12% of the total Cu) was associated For the dissolved with particulate. organic matter, and resulted in distribution coefficients (K-d) ranging between 10(4.55) and 10(5.1) phase, the portion of Cu extracted by C-18-packed cartridges averaged 44% (+11%). Radioactive Cu-64 was added to these samples to total stable Cu concentrations (17-33 nM). After 24 h of equilibration, the portion of Cu-64 associated with the particulate matter in five of the six samples (K-d between 10(4.7) and 10(5.3)) was an average of 70% higher than that of natural Cu in the ambient samples. In contrast, only 19 +/- 7% of the Cu-64 was extracted by C-18-packed cartridges. The partitioning of natural Cu and Cu-64 onto particles was not significantly different when the equilibria were based on dissolved Cu passing through the C-18 cartridges. Further research is warranted on utilizing the hydrophilic component of the dissolved phase as a parameter on which water quality criteria are based. C1 NOAA, James J Howard Lab, NE Fisheries Sci Ctr, NMFS, Highlands, NJ 07732 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Paulson, AJ (reprint author), NOAA, James J Howard Lab, NE Fisheries Sci Ctr, NMFS, 74 Magruder Rd, Highlands, NJ 07732 USA. EM anthony.paulson@noaa.gov NR 27 TC 5 Z9 5 U1 0 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD MAY PY 2001 VL 20 IS 5 BP 952 EP 959 DI 10.1002/etc.5620200503 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 457YK UT WOS:000170165800003 PM 11337883 ER PT J AU Vecchione, M Galbraith, J AF Vecchione, M Galbraith, J TI Cephalopod species collected by deepwater exploratory fishing off New England SO FISHERIES RESEARCH LA English DT Article; Proceedings Paper CT Annual Conference of the International Council for the Exploration of the Sea (ICES) CY SEP 16-18, 1998 CL LISBON, PORTUGAL DE cephalopod; squid; octopod; exploratory trawling; deepwater fishing; continental slope AB Federal resources have been used to subsidize exploratory trawling beyond the edge of the continental shelf by refitted New England fishing vessels. Potential targets include deepwater species of fishes, decapod crustaceans, and cephalopods. The first eight cruises of the F/V CONTENDER captured 18 species of cephalopods in 12 families, including four octopods, 11 oegopsid squids, one myopsid squid, and two sepiolids. One additional species of oegopsid squid was collected by jigging from F/V PERSEVERANCE. Of all the species captured, only jigging for Ommastrephes bartramii has much potential for development of a directed cephalopod fishery. Published by Elsevier Science B.V. C1 Natl Museum Nat Hist, Natl Marine Fisheries Serv, Systemat Lab, Washington, DC 20560 USA. RP Vecchione, M (reprint author), Natl Museum Nat Hist, Natl Marine Fisheries Serv, Systemat Lab, Washington, DC 20560 USA. NR 15 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD MAY PY 2001 VL 51 IS 2-3 BP 385 EP 391 DI 10.1016/S0165-7836(01)00262-4 PG 7 WC Fisheries SC Fisheries GA 424FY UT WOS:000168222700025 ER PT J AU Crone, PR AF Crone, PR TI Spatial differences in maturity schedules of female Dover sole off Oregon (1989-1991) SO FISHERIES RESEARCH LA English DT Article; Proceedings Paper CT Annual Conference of the International Council for the Exploration of the Sea (ICES) CY SEP 16-18, 1998 CL LISBON, PORTUGAL DE Dover sole (Microstomus pacificus); fishery management; groundfish fisheries; maturity schedules; logistic regression ID MICROSTOMUS-PACIFICUS AB An assessment of sexual maturity of Dover sole (Microstomus pacificus) landed in Oregon from 1989 to 1991 indicated that females of the species had a 50% probability of being mature at ages 7.3-9.5, depending on when and where the sampling was conducted. Logistic regression models were used to document statistical differences (P less than or equal to 0.05) between maturity schedules of fish harvested in the northern and southern regions of the state. There was evidence that fish from southern Oregon waters reached sexual maturity at an earlier age and exhibited higher overall rates of maturation than fish inhabiting northern waters of the state. It does not appear that the statistical findings are of magnitudes that reflect dramatic implications for management, primarily because the majority of the fish (at least 90%) did not enter the fishery until mature. It is recommended that additional information be collected regarding other vital parameters of the species, such as estimates of growth rates and mortality coefficients, to ensure exploitation strategies appropriately address the stock structure of Dover sole inhabiting US Pacific coast waters. (C) 2001 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Crone, PR (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. NR 24 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD MAY PY 2001 VL 51 IS 2-3 BP 393 EP 402 DI 10.1016/S0165-7836(01)00263-6 PG 10 WC Fisheries SC Fisheries GA 424FY UT WOS:000168222700026 ER PT J AU Welch, MJ Colbert, JC Gill, LM Phinney, CS Sharpless, KE Sniegoski, LT Wood, LJ AF Welch, MJ Colbert, JC Gill, LM Phinney, CS Sharpless, KE Sniegoski, LT Wood, LJ TI The certification of SRM 1546 - Meat Homogenate, a new reference material for nutrients in a high protein, high fat matrix SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article ID BABY FOOD COMPOSITE; VALUE ASSIGNMENT AB In response to reference material needs expressed by the food industry and government regulators, the National Institute of Standards and Technology (NIST) has developed a new Standard Reference Material (SRM) consisting of a canned meat product with certified and reference values for a large number of constituents. SRM 1546 Meat Homogenate consists of a mixture of finely ground pork and chicken prepared and canned by a commercial process. NIST determined the concentration levels of cholesterol, sodium, calcium, iron, and seven fatty acids in this SRM using well defined methods and procedures. These analytes as well as 34 other constituents or properties were determined in an interlaboratory comparison exercise involving 21 laboratories, most of which are associated with the National Food Processors Association (NFPA) Food Industry Analytical Chemists Subcommittee (FIACS). From statistical analysis of the data, NIST assigned certified concentrations for the eleven analytes measured at NIST and reference concentrations for the proximates, six additional fatty acids, seven minerals, and seven water-soluble vitamins. Information values without uncertainties are provided for the concentrations of six additional constituents for which the uncertainties could not adequately be assessed. SRM 1546 will provide Laboratories with a means to evaluate the accuracy of the methods they use to assign nutrient levels to processed meats and similar products. C1 NIST, Div Analyt Chem, Chem Sci & Technol Lab, US Dept Commerce, Gaithersburg, MD 20899 USA. RP Welch, MJ (reprint author), NIST, Div Analyt Chem, Chem Sci & Technol Lab, US Dept Commerce, Gaithersburg, MD 20899 USA. OI Sharpless, Katherine/0000-0001-6569-198X NR 13 TC 11 Z9 12 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PD MAY PY 2001 VL 370 IS 1 BP 42 EP 47 DI 10.1007/s002160100705 PG 6 WC Chemistry, Analytical SC Chemistry GA 437YU UT WOS:000169027600008 PM 11393235 ER PT J AU Bates, JJ Jackson, DL AF Bates, JJ Jackson, DL TI Trends in upper-tropospheric humidity SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID WATER-VAPOR; BRIGHTNESS TEMPERATURES; VARIABILITY; CLIMATOLOGY AB Water vapor is the most radiatively active greenhouse gas, and the process of water-vapor feedback may significantly; amplify global warming induced by anthropogenic greenhouse gasses. Satellite radiance observations from the past 20 years, which are sensitive to the mater vapor and temperature of the upper troposphere, provide the first global observations of trends in upper-tropospheric humidity. These decadal trends are strongly positive in the deep tropics, negative in the Southern Hemisphere subtropics and midlatitudes, and of mixed sign in the Northern Hemisphere subtropics and midlatitudes. The trends are shown to be consistent with atmospheric circulation changes observed in the past 20 years, including a tendency toward more EI Nino-Southern Oscillation warm events and changes in transient eddy activity in the subtropics. C1 NOAA, Environm Technol Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Bates, JJ (reprint author), NOAA, Environm Technol Lab, 325 Broadway,R-ET7, Boulder, CO 80305 USA. RI Bates, John/D-1012-2009; Jackson, Darren/D-5506-2015 OI Bates, John/0000-0002-8124-0406; Jackson, Darren/0000-0001-5211-7866 NR 15 TC 69 Z9 70 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAY 1 PY 2001 VL 28 IS 9 BP 1695 EP 1698 DI 10.1029/2000GL012544 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 424QN UT WOS:000168243100007 ER PT J AU Sainz-Trapaga, SM Goni, GJ Sugimoto, T AF Sainz-Trapaga, SM Goni, GJ Sugimoto, T TI Identification of the Kuroshio Extension, its Bifurcation and Northern Branch from altimetry and hydrographic data during October 1992-August 1999: Spatial and temporal variability SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERANNUAL VARIABILITY; PACIFIC; TOPOGRAPHY; SYSTEM AB A methodology is proposed using altimter-derived upper layer thickness and baroclinic transport to identify the Kuroshio Extension, the Bifurcation Point and the Northern Branch, by combining TOPEX/POSEIDON altimeter and climatological data within a two-layer reduced gravity model. Results obtained from the Japanese coast to 175 degreesW show that the location of the Bifurcation Point presents interannual variability that is related with upstream conditions. The longitude of the Bifurcation Point ranged from 147 to 160 degreesE. Estimates of baroclinic transport at the Kuroshio Extension and its Northern Branch decrease steadily to the east trough the region of study from 35 to 11 and from 10 to 3 Sv, respectively. C1 Univ Tokyo, Ocean Res Inst, Nakano Ku, Tokyo 1648639, Japan. NOAA, Atlantic Oceanog & Meteorol Lab, PHOD, US Dept Commerce, Miami, FL 33149 USA. RP Sainz-Trapaga, SM (reprint author), Univ Paris 06, Lab Oceanog & Climatol, Tour 15 2E,4 Pl Jussieu, F-75235 Paris, France. RI Goni, Gustavo/D-2017-2012 OI Goni, Gustavo/0000-0001-7093-3170 NR 22 TC 13 Z9 13 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 MAY 1 PY 2001 VL 28 IS 9 BP 1759 EP 1762 DI 10.1029/2000GL012323 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 424QN UT WOS:000168243100023 ER PT J AU Johnson, GC AF Johnson, GC TI The Pacific Ocean subtropical cell surface limb SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EQUATORIAL PACIFIC; TROPICAL PACIFIC; DECADAL VARIABILITY; DRIFTER DATA; CURRENTS; WIND AB The subtropical cells (STCs) cycle subtropically subducted water to the equator, where it upwells and flows poleward at the surface, exchanging heat and freshwater with the atmosphere. Pacific STC surface flow is analyzed using drifter data. Mean surface velocities are estimated. The mean divergence reveals substantial equatorial upwelling. Off-equatorial downwelling around +/-4 degrees latitude suggests that about half the upwelled water may recirculate in shallow tropical cells. Pathways and time scales for the poleward surface limb of the STC are estimated. Mean streamlines reach +/-9 degrees latitude after hair a year and +/- 22 degrees after 2 years, taking a more convoluted path in the northern hemisphere. They reenter the subtropics in the western half of the basin, far from the subduction regions feeding the equatorward limbs of the STCs, reinforcing the point that the STCs are intrinsically linked with the global ocean circulation. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Johnson, GC (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI Johnson, Gregory/I-6559-2012 OI Johnson, Gregory/0000-0002-8023-4020 NR 19 TC 44 Z9 45 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAY 1 PY 2001 VL 28 IS 9 BP 1771 EP 1774 DI 10.1029/2000GL012723 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 424QN UT WOS:000168243100026 ER PT J AU Caplan-Auerbach, J Fox, CG Duennebier, FK AF Caplan-Auerbach, J Fox, CG Duennebier, FK TI Hydroacoustic detection of submarine landslides on Kilauea volcano SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EARTHQUAKE; MECHANISM AB Landslides produced at the site where lava flows into the ocean at Kilauea volcano have been detected hydroacoustically;. Up to 10 landslides per day were detected by a hydrophone on the Hawaii Undersea Gee-Observatory (HUGO), located 50 km south of the entry site. The largest of these landslides, partly subaerial events known as bench collapses! were detected by a network of hydrophones in the eastern Pacific, 5000-7000 km away from the source. The landslides display a characteristic spectra signature easily recognizable among other signals such as earthquake T-phases and anthropogenic noises. The fact that signals are detected at great distances suggests that hydroacoustic detection of landslides could he a powerful tool in tsunami monitoring and modeling efforts. C1 Univ Hawaii, Honolulu, HI 96822 USA. Pacific Marine Environm Lab, Newport, OR 97365 USA. RP Caplan-Auerbach, J (reprint author), Univ Alaska, Alaska Volcano Observ, Fairbanks, AK 99701 USA. NR 15 TC 29 Z9 29 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAY 1 PY 2001 VL 28 IS 9 BP 1811 EP 1813 DI 10.1029/2000GL012545 PG 3 WC Geosciences, Multidisciplinary SC Geology GA 424QN UT WOS:000168243100036 ER PT J AU Forman, SL Oglesby, R Webb, RS AF Forman, SL Oglesby, R Webb, RS TI Temporal and spatial patterns of Holocene dune activity on the Great Plains of North America: megadroughts and climate links SO GLOBAL AND PLANETARY CHANGE LA English DT Review DE dune fields; Holocene climate; Great Plains; USA; droughts ID NEBRASKA SAND HILLS; CENTRAL UNITED-STATES; SOUTHERN HIGH-PLAINS; QUATERNARY EOLIAN DEPOSITION; PAST 21,000 YEARS; MIDDLE-HOLOCENE; STRATIGRAPHIC EVIDENCE; STABLE ISOTOPES; CENTRAL KANSAS; PALEOCLIMATIC SIGNIFICANCE AB The Holocene record of eolian sand and loess deposition is reviewed for numerous presently stabilized dune fields on the Great Plains of North America. Dune field activity reflects decade-to-century-scale dominance of drought that exceeded historic conditions, with a growing season deficit of precipitation > 25%. The largest dune fields, the Nebraska Sand Hills and ergs in eastern Colorado, Kansas and the Southern High Plains showed peak activity sometime between ca. 7 and 5 cal. ka. Loess deposition between ca. 10 and 4 cal. ka also signifies widespread aridity. Most dune fields exhibit evidence for one or more reactivation events sometime in the past 2 cal. ka; a number of localities register two events post 1 cal. ka, the latest potentially after 1400 AD. However, there is not a clear association of the latest dune remobilization events with up to 13 droughts in the past 2 cal. ka identified in dendroclimatic and lacustrine records. Periods of persistent drought are associated with a La Nina-dominated climate state, with cooling of sea surface temperatures in the tropical Pacific Ocean and later of the tropical Atlantic Ocean and the Gulf of Mexico that significantly weakens cyclogenesis over central North America. As drought proceeds, reduced soil moisture and vegetation cover would lessen evaporative cooling arid increase surface temperatures. These surface changes strengthen the eastward expansion of a high-pressure ridge aloft and shift the jet stream northward, further enhancing continent-wide drought. Uncertainty persists if dune fields will reactivate in the future at a scale similar to the Holocene because of widespread irrigation, the lack of migratory bison herds, and the suppression of prairie fires, all of which enhance stabilization of dune fields in the Great Plains. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. Natl Oceanog & Atmospher Adm, Off Atmospher Res, Climate Diagnost Ctr, Boulder, CO 80305 USA. RP Forman, SL (reprint author), Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA. NR 135 TC 150 Z9 153 U1 4 U2 14 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 MAY PY 2001 VL 29 IS 1-2 BP 1 EP 29 DI 10.1016/S0921-8181(00)00092-8 PG 29 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 449ET UT WOS:000169671900001 ER PT J AU Wang, B Suehle, JS Vogel, EM Bernstein, JB AF Wang, B Suehle, JS Vogel, EM Bernstein, JB TI Time-dependent breakdown of ultra-thin SiO2 gate dielectrics under pulsed biased stress SO IEEE ELECTRON DEVICE LETTERS LA English DT Article DE CMOS; defect generation; reliability; silicon dioxide; time dependent dielectric breakdown ID INTERFACE-TRAP GENERATION; SILICON DIOXIDE; HOLE INJECTION AB Ultra-thin SiO2 films (t(ox) similar to 2.0 nm) were stressed under de. unipolar, and bipolar pulsed bias conditions up to a pulse repetition frequency of 50 kHz. The time-to-breakdown (t(BD)), the number of defects at breakdown (N-BD), and the number of defects generated inside the oxide as a function of stress time were monitored during each stress condition, Oxide Lifetime under unipolar pulsed bias is similar to that under de conditions; however lifetime under bipolar pulsed bias is significantly improved and exhibits a dependence on pulse repetition frequency. The observation of a lifetime increase under bipolar pulsed bias For the oxide thickness and voltage range used in this study suggests that a different physical mechanism may be responsible for the lifetime increase from that assumed in earlier studies for thicker films. C1 Univ Maryland, Ctr Reliabil Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Wang, B (reprint author), Univ Maryland, Ctr Reliabil Engn, College Pk, MD 20742 USA. RI Vogel, Eric/A-7731-2008 OI Vogel, Eric/0000-0002-6110-1361 NR 16 TC 14 Z9 14 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD MAY PY 2001 VL 22 IS 5 BP 224 EP 226 DI 10.1109/55.919236 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 427JY UT WOS:000168402100010 ER PT J AU Remley, KA Williams, DF DeGroot, DC Verspecht, J Kerley, J AF Remley, KA Williams, DF DeGroot, DC Verspecht, J Kerley, J TI Effects of nonlinear diode junction capacitance on the nose-to-nose calibration SO IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS LA English DT Article DE digital sampling oscilloscope; nose-to-nose calibration; phase error; samplers AB We examine the effects of nonlinear diode junction capacitance on the fundamental premise of the nose-to-nose calibration, that the kickout pulse is identical in shape and duration to the impulse response of a sampling circuit. We offer a physical explanation for the error introduced by the nonlinear junction capacitance using small-signal diode equations. C1 Natl Inst Stand & Technol, RF Technol Div 813 01, Boulder, CO 80305 USA. Agilent Technol Inc, B-1050 Brussels, Belgium. Agilent Technol Inc, Colorado Springs, CO USA. RP Remley, KA (reprint author), Natl Inst Stand & Technol, RF Technol Div 813 01, Boulder, CO 80305 USA. NR 9 TC 7 Z9 9 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 1531-1309 J9 IEEE MICROW WIREL CO JI IEEE Microw. Wirel. Compon. Lett. PD MAY PY 2001 VL 11 IS 5 BP 196 EP 198 DI 10.1109/7260.923026 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 435RL UT WOS:000168894900002 ER PT J AU Masterson, KD Novotny, DR Koepke, GH AF Masterson, KD Novotny, DR Koepke, GH TI Electromagnetic shielding characteristics of optical-fiber feedthroughs SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE electromagnetic interference; fiber optic adapter barrels; fiber optic connectors; fiber optics; shielding effectiveness; mode-stirred chamber AB A number of commercially available optical-fiber connector styles ST, SC, and FC were tested to determine the extent to which their use in bulkhead adapter feedthroughs would compromise the shielding of electromagnetic interference for electronic enclosures. Connectors and adapter barrels made from metal, ceramic, and polymer materials were included in the tests. The tests were carried out using a nested reverberation cell and covered a frequency range from 1 to 16 GHz, Although we rely on data acquired by making shielding effectiveness (SE) measurements, we report the results in terms of a transmission cross section which is the ratio of the power coupled into an enclosure through an aperture to the power per unit area incident on the aperture. The amount of coupling through the feedthroughs we tested varied over 70 dB, The shielding of an all-metal FC connector system was nearly equal to that of a blank reference plate. In some cases, a feedthrough coupled more energy into the enclosure than was coupled through the empty hole required to mount the adapter barrel, Unlike SE, the transmission cross sections do not depend on the volume, shape, or construction materials of the enclosure and can be used to estimate the degradation in the SE for enclosures other than our reference cell. The uncertainties in the reported transmission cross sections are calculated to be +/-3 dB and are small compared to the differences between the measured cross sections. C1 Natl Inst Stand & Technol, Div Electromagnet Fields, Boulder, CO 80305 USA. RP Natl Inst Stand & Technol, Div Electromagnet Fields, Boulder, CO 80305 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9375 EI 1558-187X J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD MAY PY 2001 VL 43 IS 2 BP 177 EP 186 DI 10.1109/15.925538 PG 10 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 438ER UT WOS:000169041200009 ER PT J AU Della Torre, E Bennett, LH AF Della Torre, E Bennett, LH TI Temperature variation of magnetic aftereffect SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article DE accelerated testing; chemical potential; magnetic aftereffect; quantum statistics ID VISCOSITY AB The paper analyzes the anomalous behavior of the magnetic aftereffect decay coefficient with temperature, which has been established experimentally from a thermodynamic point of view. The Arrhenius law, which has often been used to model magnetic aftereffect, is based on the Maxwell-Boltzmann (MB) statistics. At low temperatures, however, magnons obey Bose-Einstein (BE) statistics, which have a different energy spectrum. MB statistics are a good approximation to BE statistics in the temperature range in which most devices operate. The variation in temperature, governed by chemical potential that is essentially linear, has a negative slope and is zero below a low but finite temperature. Other explanations for this anomalous behavior would predict an incorrect type of temperature dependence. This new interpretation of magnetic aftereffect may have profound implications on accelerated testing to determine life expectancy of recordings. C1 NIST, Gaithersburg, MD 20899 USA. George Washington Univ, Washington, DC 20052 USA. RP Della Torre, E (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 11 TC 12 Z9 12 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAY PY 2001 VL 37 IS 3 BP 1118 EP 1122 DI 10.1109/20.920486 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 428JT UT WOS:000168459100009 ER PT J AU Hersh, W Over, P AF Hersh, W Over, P TI Interactivity at the Text Retrieval Conference (TREC) SO INFORMATION PROCESSING & MANAGEMENT LA English DT Editorial Material C1 Oregon Hlth Sci Univ, Div Med Informat & Outcomes Res, Portland, OR 97201 USA. Natl Inst Stand & Technol, Retrieval Grp, Informat Access Div, Gaithersburg, MD USA. RP Hersh, W (reprint author), Oregon Hlth Sci Univ, Div Med Informat & Outcomes Res, 3181 SW Sam Jackson Pk Rd, Portland, OR 97201 USA. NR 9 TC 14 Z9 14 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0306-4573 J9 INFORM PROCESS MANAG JI Inf. Process. Manage. PD MAY PY 2001 VL 37 IS 3 BP 365 EP 367 DI 10.1016/S0306-4573(00)00052-2 PG 3 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA 407UW UT WOS:000167290000001 ER PT J AU Over, P AF Over, P TI The TREC interactive track: an annotated bibliography SO INFORMATION PROCESSING & MANAGEMENT LA English DT Article DE information retrieval; TREC; interactive AB The study of interactive information retrieval (IR) has been a small but constant part of the Text REtrieval Conferences (TREC 1-8) from the beginning. The main arena for such work has been the Interactive Track (TREC 3-8). This report presents a bibliography of those efforts together with a summary of the evolving experimental framework within which the studies took place. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Retrieval Grp, Informat Access Div, Gaithersburg, MD 20899 USA. RP Over, P (reprint author), Natl Inst Stand & Technol, Retrieval Grp, Informat Access Div, Gaithersburg, MD 20899 USA. NR 41 TC 18 Z9 18 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0306-4573 J9 INFORM PROCESS MANAG JI Inf. Process. Manage. PD MAY PY 2001 VL 37 IS 3 BP 369 EP 381 DI 10.1016/S0306-4573(00)00053-4 PG 13 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA 407UW UT WOS:000167290000002 ER PT J AU Groisman, PY Rankova, EY AF Groisman, PY Rankova, EY TI Precipitation trends over the Russian permafrost-free zone: Removing the artifacts of pre-processing SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE precipitation trends; Russia; wetting adjustments ID BIASES AB Rain gauge changes, changes in the number of observations per day, and inconsistent corrections to ob;served precipitation data during the 20th century of the meteorological network of the former Soviet Union make it difficult to address the issue of century time-scale precipitation changes. In this paper, we use daily and sub-daily synoptic data to account for the effects of these changes on the instrumental homogeneity of precipitation measurements over the Russian permafrost-free zone (RPF, most populous western and central parts of the country). Re-adjustments that were developed during this assessment allow us to (a) develop a system of scale corrections that remove the inhomogeneity owing to wetting/observation time changes over most of the former Soviet Union during the past century, and (b) to estimate precipitation trends over the RPF, reconciling previously contradictory results. The trend that emerges is an increase of about 5% per century. This estimate can be further refined after a more comprehensive set of supplementary data (precipitation type and wind) and metadata (information about the exposure of meteorological sites) is employed. Copyright (C) 2001 Royal Meteorological Society. C1 Natl Climat Data Ctr, UCAR Project, Asheville, NC 28801 USA. Natl Climat Data Ctr, UCAR Project Sci, Asheville, NC 28801 USA. Russian Fed, Inst Global Climate & Ecol, Moscow, Russia. RP Groisman, PY (reprint author), Natl Climat Data Ctr, UCAR Project, Fed Bldg,151 Patton Ave, Asheville, NC 28801 USA. NR 36 TC 36 Z9 38 U1 1 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD MAY PY 2001 VL 21 IS 6 BP 657 EP 678 DI 10.1002/joc.627 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 439PL UT WOS:000169126200001 ER PT J AU Moldover, MR Buckley, TJ AF Moldover, MR Buckley, TJ TI Reference values of the dielectric constant of natural gas components determined with a cross capacitor SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE argon; carbon dioxide; cross capacitor; dielectric constant; dielectric polarizability; helium; methane; molar polarizability; natural gas; nitrogen; reference data ID PRESSURE VIRIAL-COEFFICIENTS; IMPERFECT GASES; MELTING LINE; FLUID REGION; TEMPERATURE; EQUATION; HELIUM; STATE; MPA; NITROGEN AB A novel toroidal cross capacitor was used to measure accurately the dielectric polarizability epsilon (p) (i.e., the dielectric constant as a function of the pressure) of helium, argon, nitrogen, methane, and carbon dioxide at T=50 degreesC. The data extend up to 7 MPa (5 MPa for CO2) and may be useful for calibrating on-line, capacitance-based systems that are designed to measure the heating value of natural gas. The uncertainties of e and p are 4 x 10(-6) and (3.0 x 10(-5) p + 84 Pa), respectively. The properties of helium that had been calculated ab initio from quantum mechanics were used to verify that the cross capacitor deformed in a predictable manner under hydrostatic (gas) pressure. Thus, a common cause of systematic errors in measuring the dielectric constant of gases was avoided. For helium, the rms deviation of epsilon (p) from the calculations was only 2.7 x 10(-7). This suggests that the estimated uncertainty is very conservative. C1 Natl Inst Stand & Technol, Proc Measurements Div, Gaithersburg, MD 20899 USA. RP Moldover, MR (reprint author), Natl Inst Stand & Technol, Proc Measurements Div, 100 Bur Dr,Stop 8360, Gaithersburg, MD 20899 USA. RI Moldover, Michael/E-6384-2013 NR 35 TC 20 Z9 20 U1 0 U2 5 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD MAY PY 2001 VL 22 IS 3 BP 859 EP 885 DI 10.1023/A:1010731117103 PG 27 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 464GA UT WOS:000170523800010 ER PT J AU Egelhoff, WF Chen, PJ McMichael, RD Powell, CJ Deslattes, RD Serpa, FG Gomez, RD AF Egelhoff, WF Chen, PJ McMichael, RD Powell, CJ Deslattes, RD Serpa, FG Gomez, RD TI Surface oxidation as a diffusion barrier for Al deposited on ferromagnetic metals SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID BY-LAYER GROWTH; MAGNETIC TUNNEL-JUNCTIONS; FCC-FE FILMS; HOMOEPITAXIAL GROWTH; MAGNETORESISTANCE; CU(100); SUPERLATTICES; SCATTERING; EPITAXY; AG(111) AB Grazing incidence x-ray reflectometry has been used to study surface oxidation as a diffusion barrier for Al deposited on ferromagnetic metals (Co, Fe, Ni, and Ni80Fe20). Samples of the form SiO2\ 10 nm X \4 nm Al with X =(Co, Fe, Ni, and Ni80Fe20) were investigated for X \ Al intermixing. Surface oxidation was achieved by exposing the ferromagnetic layer to O-2 to oxidize the top two or three atomic layers before depositing the Al layer. Specular x-ray scans were used for the analysis. Samples of the form SiO2\ 10 nm X \4 nm Au were used to separate topographical roughness from intermixing. Surface oxidation was found to suppress the diffusion of Al into Co, Ni, and Ni80Fe20 but not into Fe. (C) 2001 American Institute of Physics. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Elect Engn, College Pk, MD 20742 USA. RP Egelhoff, WF (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 24 TC 32 Z9 32 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 1 PY 2001 VL 89 IS 9 BP 5209 EP 5214 DI 10.1063/1.1359151 PG 6 WC Physics, Applied SC Physics GA 422QE UT WOS:000168130100080 ER PT J AU Luy, B Marino, JP AF Luy, B Marino, JP TI Measurement and application of H-1-F-19 dipolar couplings in the structure determination of 2 '-fluorolabeled RNA SO JOURNAL OF BIOMOLECULAR NMR LA English DT Article DE dipolar couplings; dipolar-TOCSY; E.COSY; fluorine; MOCCA; RNA ID NUCLEAR-MAGNETIC-RESONANCE; LIQUID-CRYSTALLINE PHASE; PROTON SCALAR COUPLINGS; NMR STRUCTURES; ORIENTED MACROMOLECULES; MOLECULAR ALIGNMENT; GLOBAL STRUCTURE; STATE NMR; PROTEINS; HETERONUCLEAR AB Residual dipolar couplings can provide powerful restraints for determination and refinement of the solution structure of macromolecules. The application of these couplings in nucleic acid structure elucidation can have an especially dramatic impact, since they provide long-range restraints, typically absent in NOE and J-coupling measurements. Here we describe sensitive X-filtered-E.COSY-type methods designed to measure both the sign and magnitude of long-range H-1-F-19 dipolar couplings in selectively fluorine labeled RNA oligonucleotides oriented in solution by a liquid crystalline medium. The techniques for measuring H-1-F-19 dipolar couplings are demonstrated on a 21-mer RNA hairpin, which has been specifically labeled with fluorine at the 2'-hydroxyl position of three ribose sugars. Experimentally measured H-1-F-19 dipolar couplings for the 2'-deoxy-2'-fluoro-sugars located in the helical region of the RNA hairpin were found to be in excellent agreement with values predicted using canonical A-form helical geometry, demonstrating that these couplings can provide accurate restraints for the refinement of RNA structures determined by NMR. C1 Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Rockville, MD 20850 USA. RP Marino, JP (reprint author), Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. RI Luy, Burkhard/I-1918-2013 OI Luy, Burkhard/0000-0001-9580-6397 FU NIGMS NIH HHS [GM 59107-01] NR 48 TC 28 Z9 28 U1 1 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0925-2738 J9 J BIOMOL NMR JI J. Biomol. NMR PD MAY PY 2001 VL 20 IS 1 BP 39 EP 47 DI 10.1023/A:1011210307947 PG 9 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA 432CJ UT WOS:000168669300006 PM 11430754 ER PT J AU Tees, DFJ Woodward, JT Hammer, DA AF Tees, DFJ Woodward, JT Hammer, DA TI Reliability theory for receptor-ligand bond dissociation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ATOMIC-FORCE MICROSCOPY; MOLECULAR ADHESION; CARBOHYDRATE BOND; CELLS; ANTIBODY; TITIN; SPECTROSCOPY; SHEAR; FLOW AB Cell adhesion in the presence of hydrodynamic forces is a critical factor in inflammation, cancer metastasis, and blood clotting. A number of assays have recently been developed to apply forces to small numbers of the receptor-ligand bonds responsible for adhesion. Examples include assays using hydrodynamic shear in flow chambers or elastic probe deflection assays such as the atomic force microscope or the biomembrane force probe. One wishes to use the data on the time distribution of dissociation from these assays to derive information on the force dependence of reaction rates, an important determinant of cell adhesive behavior. The dissociation process can be described using the theory developed for reliability engineering of electronic components and networks. We use this framework along with the Bell model for the reverse reaction rate (k(r) = k(r)(0) exp[r(0) f/kT], where f is the applied force and k(r)(0) and r(0) are Bell model parameters) to write closed form expressions for the probability distribution of break-up with multiple independent or interacting bonds. These expressions show that the average lifetime of n bonds scales with the nth harmonic number multiplied by the lifetime of a single bond. Results from calculation and simulations are used to describe the effect of experimental procedures in forced unbinding assays on the estimation of parameters for the force dependence of reverse reaction rates. (C) 2001 American Institute of Physics. C1 Univ Penn, Dept Bioengn, Philadelphia, PA 19104 USA. Univ Penn, Inst Med & Engn, Dept Chem Engn, Philadelphia, PA 19104 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Hammer, DA (reprint author), Univ Penn, Dept Bioengn, 120 Hayden Hall, Philadelphia, PA 19104 USA. NR 34 TC 41 Z9 41 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 1 PY 2001 VL 114 IS 17 BP 7483 EP 7496 DI 10.1063/1.1356030 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 423GT UT WOS:000168168100021 ER PT J AU Lobkovsky, AE Warren, JA AF Lobkovsky, AE Warren, JA TI Phase-field model of crystal grains SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE crystal morphology; crystallites; growth models; recrystallization ID BOUNDARY; CRYSTALLIZATION; ROTATION AB We introduce a two-dimensional phase field model designed to describe the dynamics of crystalline groins. The phenomenological free energy is a function of two order parameters. They reflect the degree of orientational order as well as the predominant local orientation of the crystal. Solutions: to the gradient flow of this free energy can be interpreted as ensembles of grains tin which the phase of the order parameter is approximately constant in space) separated by mobile grain boundaries. We study the dynamics of the boundaries us well as the rotation of the grains. In the limit of the infinitely sharp interface, the normal velocity of the boundary is proportional to its curvature and its energy. The mobility of a grain boundary has a strong divergence in the limit of the small orientation mismatch. We derive and solve approximate equations describing a circular grain embedded in a fixed matrix. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Lobkovsky, AE (reprint author), Natl Inst Stand & Technol, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 16 TC 14 Z9 15 U1 2 U2 5 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 MAY PY 2001 VL 225 IS 2-4 BP 282 EP 288 DI 10.1016/S0022-0248(01)00867-3 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300033 ER PT J AU Singh, NB Coriell, SR Duval, WMB Mani, SS Green, K Glicksman, ME AF Singh, NB Coriell, SR Duval, WMB Mani, SS Green, K Glicksman, ME TI Thermal conductivity measurement in lead bromide SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE heat transfer; solidification; halides; acousto-optic materials ID INSTABILITIES AB The ratio of liquid and solid thermal conductivities was determined for lead bromide by measuring the temperature of solid and liquid under the steady-state conditions. The liquid thermal conductivity was determined to be 10.5 x 10(-4)Cal/K s cm, a value 1.65 times higher than that reported for the solid. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Northrop Grumman Corp, Ctr Sci & Technol, ESSS, Linthicum, MD 21090 USA. NIST, Gaithersburg, MD 20889 USA. NASA, John Glenn Res Ctr, Cleveland, OH 44135 USA. Rensselaer Polytech Inst, Dept Mat Sci & Engn, Troy, NY 12180 USA. RP Singh, NB (reprint author), Northrop Grumman Corp, Ctr Sci & Technol, ESSS, ATL-3D14,1212 Winterson Rd, Linthicum, MD 21090 USA. OI Glicksman, Martin/0000-0002-2675-2759 NR 4 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD MAY PY 2001 VL 225 IS 2-4 BP 512 EP 515 DI 10.1016/S0022-0248(01)00958-7 PG 4 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300074 ER PT J AU Riley, P Gosling, JT Pizzo, VJ AF Riley, P Gosling, JT Pizzo, VJ TI Investigation of the polytropic relationship between density and temperature within interplanetary coronal mass ejections using numerical simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WIND THERMAL ELECTRONS; SOLAR-WIND; MAGNETIC CLOUDS; EVOLUTION; PARAMETERS; ULYSSES; PLASMA; INDEX AB Single-point spacecraft. measurements within coronal mass ejections (CMEs) often exhibit a negative correlation between electron density and temperature. At least two opposing interpretations ha c:e been suggested for this relationship. If, on one hand, these single spacecraft. observations provide direct measures of the polytropic properties of the plasma, then they imply that the polytropic index for the electrons gamma (e) is often < 1. Moreover, since the electrons carry the bulk of the pressure (via their significantly higher temperature), this further implies that the dynamics of CME evolution are dominated by an effective polytropic index gamma (eff) < 1. On the other hand, gamma < 1 implies that as the ejecta propagate away from the Sun and expand, they also heat up; a result clearly at odds with in situ observations. In contrast to these CME intervals, many studies have shown that the quiescent solar wind exhibits a positive correlation between electron density and temperature, suggesting that gamma (e) > 1. In this study we simulate the evolution of a variety of CME-like disturbances in the solar wind using a one-dimensional, single-fluid model, to address the interpretation of the relationship between electron density and temperature within CMEs at fixed locations in space. Although we strictly impose a polytropic relationship (with gamma = constant) throughout our simulations, we demonstrate that a variety of correlations can ex-ist between density and temperature at fixed points. Furthermore, we demonstrate that the presence of only local uncorrelated random fluctuations in density and temperature can produce a negative correlation. Consequently, we conclude that these single-point observations of negative correlations between electron density and temperature cannot be used to infer the value of gamma (e). Instead, we suggest that entropy variations, together with the plasma's tendency to achieve pressure balance with its surroundings, are responsible for the observed profiles. C1 Sci Applicat Int Corp, San Diego, CA 92121 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Riley, P (reprint author), Sci Applicat Int Corp, San Diego, CA 92121 USA. NR 25 TC 15 Z9 15 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 2001 VL 106 IS A5 BP 8291 EP 8300 DI 10.1029/2000JA000276 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 428VL UT WOS:000168482300017 ER PT J AU Silva, CC McHenry, ME AF Silva, CC McHenry, ME TI Measurement and interpretation of AC susceptibility and loss in high-temperature superconductors SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE superconductivity-high T-c; susceptibility-AC; anisotrophy; magnetic coupling ID SINGLE-CRYSTALS AB Intrinsic and hysteretic AC losses were investigated in high-temperature superconductors. A quantum design physical property measurement system magnetometer was used to measure AC susceptibility as a function of magnetic field. frequency, temperature and field history. Three types of loss mechanisms were observed and each associated with a different loss peak on the imaginary component of the AC susceptibility: the intrinsic, the intergranular and the intragranular peaks. The peaks were observed to change systematically with temperature and magnetic field, either in polycrystalline or single crystals. YBCO polycrystalline samples were prepared by three different techniques: solid-state synthesis, melt-process melt-growth and freeze-dried and studied both as bulk and powder samples. LSCO and BSCCO-2223 single crystals were studied and compared to polycrystalline samples. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Silva, CC (reprint author), Natl Inst Stand & Technol, 19307 Golden Meadow Dr, Gaithersburg, MD 20899 USA. RI McHenry, Michael/B-8936-2009 NR 9 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAY PY 2001 VL 226 SI SI BP 311 EP 313 DI 10.1016/S0304-8853(00)01360-3 PN 1 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600110 ER PT J AU Rezende, SM Lucena, MA Azevedo, A Oliveira, AB de Aguiar, FM Egelhoff, WF AF Rezende, SM Lucena, MA Azevedo, A Oliveira, AB de Aguiar, FM Egelhoff, WF TI Exchange anisotropy in NiFe films on (100) NiO single-crystal substrate SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE magnetic excitations; resonance-ferromagnetic; spin waves; multilayers-metallic ID MODEL; BIAS AB The exchange anisotropy in a Ni81Fe19 film sputtered on a (100) NiO single-crystal substrate is investigated with MOKE magnetometry, ferromagnetic resonance (FMR) and Brillouin light scattering (BLS). The dependencies of the spin-wave frequency and FMR resonance field with the angle of the in-plane field are strikingly different than in polycrystalline samples. The BLS and FMR data are interpreted with a model that includes a planar domain wall in the AF substrate while the exchange field in the single-crystal sample is quite larger than in NiFe films on polycrystalline NiO layers, the domain wall field is smaller. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Fed Pernambuco, Dept Fis, BR-50670901 Recife, PE, Brazil. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Rezende, SM (reprint author), Univ Fed Pernambuco, Dept Fis, BR-50670901 Recife, PE, Brazil. RI Rezende, Sergio/G-4570-2014 OI Rezende, Sergio/0000-0002-3806-411X NR 8 TC 4 Z9 4 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAY PY 2001 VL 226 SI SI BP 1683 EP 1685 DI 10.1016/S0304-8853(00)01200-2 PN 2 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 466DE UT WOS:000170628400222 ER PT J AU Kepa, H Kutner-Pielaszek, J Twardowski, A Sipatov, AY Majkrzak, CF Story, T Galazka, RR Giebultowicz, TM AF Kepa, H Kutner-Pielaszek, J Twardowski, A Sipatov, AY Majkrzak, CF Story, T Galazka, RR Giebultowicz, TM TI Interlayer correlations in ferromagnetic semiconductor superlattices EuS/PbS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE semiconductors-ferromagnetic; superlattices; correlations AB Neutron diffraction and reflectivity data from all-semiconductor ferromagnetic/diamagnetic superlattices EuS/PbS provide direct evidence of antiferromagnetic coupling between EuTe layers across up to 90 Angstrom of diamagnetic PbS, despite the absence of mobile carriers that can support long-range RKKY interactions. (C) 2001 Published by Elsevier Science B.V. C1 Oregon State Univ, Dept Phys, Corvallis, OR 97331 USA. Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Kharkov State Polytech Univ, UA-310002 Kharkov, Ukraine. Univ Warsaw, Dept Phys, PL-00681 Warsaw, Poland. RP Giebultowicz, TM (reprint author), Oregon State Univ, Dept Phys, 301 Weniger Hall, Corvallis, OR 97331 USA. OI Sipatov, Alexander/0000-0002-2693-2135 NR 4 TC 3 Z9 3 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAY PY 2001 VL 226 SI SI BP 1795 EP 1797 PN 2 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 466DE UT WOS:000170628400261 ER PT J AU Valle-Levinson, A Wong, KC Bosley, KT AF Valle-Levinson, A Wong, KC Bosley, KT TI Observations of the wind-induced exchange at the entrance to Chesapeake Bay SO JOURNAL OF MARINE RESEARCH LA English DT Article ID COASTAL-PLAIN ESTUARY; SUBTIDAL SEA-LEVEL; SAN-FRANCISCO BAY; DRIVEN CIRCULATION; SHALLOW BAY; VARIABILITY; RIVER; CURRENTS; POINT; FLOW AB Water density and velocity data from two similar to 75-day deployments across the entrance to the Chesapeake Bay were used in conjunction with wind velocity and sea level records to describe the transverse structure of wind-induced subtidal exchange. Acoustic Doppler current profilers, electromagnetic current meters, and conductivity-temperature-depth recorders were deployed at the entrance to the bay from mid-April to early July of 1999 and from early September to mid-November of 1999. Three main scenarios of wind-induced exchange were identified: (1) Northeasterly (NE) winds consistently drove water from the coast toward the lower Chesapeake Bay as well as water from the upper bay to the lower bay, which was indicated by the surface elevation slopes across the lower bay and along the bay, This resulted in water piling up against the southwestern corner of the bay. The subtidal flow over the southern portion of the bay entrance was directed to the left of the wind direction, likely the result of the influence of Coriolis and centripetal accelerations on the adjustment of the sea level gradients, Over the northern shallow half of the entrance, the subtidal flows were nearly depth-independent and in the same direction as the wind. (2) Southwesterly (SW) winds caused opposite sea level gradients (relative to NE winds), which translated into near-surface outflows throughout the entrance and near-bottom inflows restricted to the channels. This wind-induced circulation enhanced the two-way exchange between the estuary and the adjacent ocean. (3) Northwesterly winds produced the same exchange pattern as NE winds. Water piled up against the southwestern corner of the bay causing net outflow in the deep, southern area and downwind flow over the shallow areas. Northwesterly winds greater than 12 m/s caused the most efficient flushing of the bay, driving water out over the entire mouth of the estuary. C1 Old Dominion Univ, Ctr Coastal Phys Oceanog, Dept Ocean Earth & Atmospher Sci, Norfolk, VA 23529 USA. Univ Delaware, Coll Marine Studies, Newark, DE 19716 USA. NOAA, Natl Ocean Serv, Norfolk, VA 23529 USA. RP Valle-Levinson, A (reprint author), Old Dominion Univ, Ctr Coastal Phys Oceanog, Dept Ocean Earth & Atmospher Sci, Norfolk, VA 23529 USA. NR 43 TC 31 Z9 32 U1 0 U2 2 PU KLINE GEOLOGY LABORATORY PI NEW HAVEN PA YALE UNIV, NEW HAVEN, CT 06520-8109 USA SN 0022-2402 J9 J MAR RES JI J. Mar. Res. PD MAY PY 2001 VL 59 IS 3 BP 391 EP 416 DI 10.1357/002224001762842253 PG 26 WC Oceanography SC Oceanography GA 461QL UT WOS:000170374900003 ER PT J AU Zhao, H Hu, XZ Bush, MB Lawn, BR AF Zhao, H Hu, XZ Bush, MB Lawn, BR TI Cracking of porcelain coatings bonded to metal substrates of different modulus and hardness SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CONTACT DAMAGE; HERTZIAN CONTACTS; BRITTLE COATINGS; CERAMIC COATINGS; FRACTURE; DEFORMATION; INDENTATION; ALUMINA; INTERLAYER AB A preceding study of contact damage in a bilayer system consisting of a porcelain coating on a stiff Pd-alloy substrate is here expanded to investigate the role of substrate modulus and hardness. Bilayers are made by fusing the same dental porcelain onto Co-, Pd-, and Au-alloy metal bases. Indentations are made on the porcelain surfaces using spheres of radii 2.38 and 3.98 mm. Critical loads to initiate cone fracture at the top surface of the porcelain and yield in the substrate below the contact are measured as a function of porcelain thickness. Radial cracks form at the lower surface of the coating once the substrate yield is well developed. By virtue of its controlling role in the metal yield process, substrate hardness is revealed to be a key material parameter-substrate modulus plays a secondary role. A simple elasticity-based analysis for predetermining critical loads for a given brittle/plastic bilayer system is presented. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Western Australia, Dept Mech & Mat Engn, Nedlands, WA 6907, Australia. RP Zhao, H (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Hu, Xiaozhi /H-4353-2011 NR 27 TC 29 Z9 30 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD MAY PY 2001 VL 16 IS 5 BP 1471 EP 1478 DI 10.1557/JMR.2001.0205 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 429AW UT WOS:000168494700038 ER PT J AU Du, BY VanLandingham, MR Zhang, QL He, TB AF Du, BY VanLandingham, MR Zhang, QL He, TB TI Direct measurement of plowing friction and wear of a polymer thin film using the atomic force microscope SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID RESISTANCE; INDENTATION AB Nanometer-scale plowing friction and wear of a polycarbonate thin film were directly measured using an atomic force microscope (AFM) with nanoscratching capabilities. During the nanoscratch tests, lateral forces caused discrepancies between the maximum forces for the initial loadings prior to the scratch and the unloading after the scratch. In the case of a nanoscratch test performed parallel to the cantilever probe axis, the plowing friction added another component to the moment acting at the cantilevered end compared to the case of nanoindentation, resulting in an increased deflection of the cantilever. Using free-body diagrams for the cases of nanoindentation and nanoscratch testing, the AFM force curves were analyzed to determine the plowing friction during nanoscratch testing. From the results of this analysis, the plowing friction was found to be proportional to the applied contact force, and the coefficient of plowing friction was measured to be 0.56 +/- 0.02. Also, by the combination of nanoscratch and nanoindentation testing, the energetic wear rate of the polycarbonate thin film was measured to be 0.94 +/- 0.05 mm(3)/(N m). C1 Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Polymer Phys & Chem, Changchun 130022, Peoples R China. NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP He, TB (reprint author), Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Polymer Phys & Chem, Changchun 130022, Peoples R China. NR 12 TC 30 Z9 31 U1 0 U2 3 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 MAY PY 2001 VL 16 IS 5 BP 1487 EP 1492 DI 10.1557/JMR.2001.0207 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 429AW UT WOS:000168494700040 ER PT J AU Hougen, JT AF Hougen, JT TI Torsional splittings in small-amplitude vibrational fundamental states of methanol-type molecules SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID ETHANE-LIKE MOLECULES; INFRARED-SPECTRUM; INTERNAL-ROTOR; ROTATION; DIMETHYLACETYLENE; MODE; BAND; (GE2H6)-GE-70 AB lGroup-theoretical methods are used to show that inverted torsional splittings in fundamental levels of small-amplitude vibrations of methanol-like molecules can be parameterized and understood in terms of the energy level patterns induced when a pair of high-barrier torsionally split components of given v(t) and (t)A + E-t symmetry species in the molecular symmetry group G(6) is allowed to interact with small-amplitude vibrational modes of symmetry E-v. Such doubly degenerate E-v vibrational modes arise rather naturally in G(6) (isomorphic with the point-group C-3v) for those methyl-group vibrations in print-group-C-s asymmetric tops such as CH3-CHO that are analogs of the degenerate methyl-group stretch, bend, and rocking vibrations in point-group-C-3v symmetric tops such as CH3-C=C-H. The present group-theoretical treatment is somewhat different from, but (as a comparison of model parameters shows) still fundamentally similar to, the recent local mode explanation of inverted torsional splittings in the C-H stretching fundamental region in methanol. (C) 2001 Academic Press. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Hougen, JT (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 21 TC 29 Z9 29 U1 0 U2 7 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 MAY PY 2001 VL 207 IS 1 BP 60 EP 65 DI 10.1006/jmsp.2001.8329 PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 435ZY UT WOS:000168913100009 ER PT J AU Walker, ARH Suenram, RD Samuels, A Jensen, J Ellzy, MW Lochner, JM Zeroka, D AF Walker, ARH Suenram, RD Samuels, A Jensen, J Ellzy, MW Lochner, JM Zeroka, D TI Rotational spectrum of Sarin SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID INTERNAL-ROTATION; MOLECULAR-BEAM; MICROWAVE; GASES AB As part of an effort to examine the possibility of using molecular-beam Fourier-transform microwave spectroscopy to unambiguously detect and monitor chemical warfare agents, we report the first observation and assignment of the rotational spectrum of the nerve agent Sarin (GB) (Methylphosphonofluoridic acid 1-methyl-ethyl ester, CAS #107-44-8) at frequencies between 10 and 22 GHz. Only one of the two low-energy conformers of this oganophosphorus compound (C4H10FO2P) was observed in the rotationally cold (T-rot < 2 K) molecular beam. The experimental asymmetric-rotor ground-state rotational constants of this conformer are A = 2874.0710(9) MHz, B = 1168.5776(4) MHz, C = 1056.3363(4) MHz (Spe A standard uncertainties are given, i.e., 1 ), as obtained from a least-squares analysis of 74 n-, L7-, and c type rotational transitions. Several of the transitions are split into doublets due to the internal rotation of the methyl group attached to the phosphorus. The three-fold-symmetry barrier to internal rotation estimated from these splittings is 677.0(4) cm(-1). Ab initio electronic structure calculations using Hartree-Fock, density functional, and Moller-Plesset perturbation theories have also been made. The structure of the lowest-energy conformer determined from a structural optimization at the MP2/6-311G'* level of theory is consistent with our experimental findings. (C) 2001 Academic Press. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Edgewood Res Dev & Engn Ctr, Aberdeen Proving Grounds, Aberdeen, MD 21010 USA. Lehigh Univ, Dept Chem, Bethlehem, PA 18015 USA. RP Walker, ARH (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 13 TC 29 Z9 29 U1 1 U2 6 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 MAY PY 2001 VL 207 IS 1 BP 77 EP 82 DI 10.1006/jmsp.2001.8307 PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 435ZY UT WOS:000168913100012 ER PT J AU Zeissler, CJ Lindstrom, RM McKinley, JP AF Zeissler, CJ Lindstrom, RM McKinley, JP TI Radioactive particle analysis by digital autoradiography SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID IMAGING PLATE; PHOSPHORS AB We have been exploring ways to evaluate the activity of radioactive particles that have been detected by phosphor plate digital autoradiography based on photostimulated luminescence (PSL). A PSL system with 25 mum pixel digitization has been applied to particle analysis problems, both qualitatively and quantitatively. Two data evaluation methods are currently employed: (1) bulk area signal measurement, and (2) discrete event counting which may include spectral evaluation. The first method is conventional, whereas the second method requires high spatial resolution and is presented here for the first time. The counting methods can discriminate between alpha and background counts. The unshielded background signal accumulation rate was determined by the bulk area method. Using the spectral method of evaluation for a-particle events, the mean signal intensity per recorded a-particle was measured, and the detective quantum efficiency (DQE) was found to be nominally 100%. We present a comparison to gamma-spectrometry for sub-Bq Cs-137 activities, and demonstrate an application for the qualitative assay of International Atomic Energy Agency swipe samples collected from uranium enrichment facilities. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Zeissler, CJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 19 TC 20 Z9 20 U1 0 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD MAY PY 2001 VL 248 IS 2 BP 407 EP 412 DI 10.1023/A:1010640411441 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 446MA UT WOS:000169516000025 ER PT J AU Nechvatal, J Barker, E Bassham, L Burr, W Dworkin, M Foti, J Roback, E AF Nechvatal, J Barker, E Bassham, L Burr, W Dworkin, M Foti, J Roback, E TI Report on the development of the Advanced Encryption Standard (AES) SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE Advanced Encryption Standard (AES); cryptography; cryptanalysis; cryptographic algorithms; encryption; Rijndael AB In 1997, the National Institute of Standards and Technology (NIST) initiated a process to select a symmetric-key encryption algorithm to be used to protect sensitive (unclassified) Federal information in furtherance of NIST's statutory responsibilities. In 1998, NIST announced the acceptance of 15 candidate algorithms and requested the assistance of the cryptographic research community in analyzing the candidates. This analysis included an initial examination of the security and efficiency characteristics for each algorithm. NIST reviewed the results of this preliminary research and selected MARS, RC(TM), Rijndael, Serpent and Twofish as finalists. Having reviewed further public analysis of the finalists, NIST has decided to propose Rijndael as the Advanced Encryption Standard (AES). The research results and rationale for this selection are documented in this report. C1 Natl Inst Stand & Technol, Div Comp Secur, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP Nechvatal, J (reprint author), Natl Inst Stand & Technol, Div Comp Secur, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 97 TC 7 Z9 7 U1 2 U2 12 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 2001 VL 106 IS 3 BP 511 EP 576 PG 66 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 455CJ UT WOS:000170009700001 PM 27500035 ER PT J AU Eppeldauer, GP Martin, RJ AF Eppeldauer, GP Martin, RJ TI Photocurrent measurement of PC and PVHgCdTe detectors SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE detector; drift; HgCdTe; infrared; noise; photoconductive; photocurrent; photodiode; preamplifier AB Novel preamplifiers for working standard photoconductive (PC) and photovoltaic (PV) HgCdTe detectors have been developed to maintain the spectral responsivity scale of the National Institute of Standards and Technology (NIST) in the wavelength range of 5 mum to 20 mum. The linear PC mode preamplifier does not need any compensating source to zero the effect of the detector bias current for the preamplifier output. The impedance multiplication concept with a positive feedback buffer amplifier was analyzed and utilized in a bootstrap PV transimpedance amplifier to measure photocurrent of a 200 Ohm shunt resistance photodiode with a maximum signal gain of 10(8) V/A. In spite of the high performance lock-in used as a second-stage signal-amplifier, the signal-to-noise ratio had to be optimized for output of the photocurrent preamplifiers. Noise and drift were equalized for the output of the PV mode preamplifier. The signal gain errors were calculated to determine the signal frequency range where photocurrent-to-voltage conversion can be performed with very low uncertainties. For the design of both PC and PV detector preamplifiers, the most important gain equations are described. Measurement results on signal ranges and noise performance are discussed. C1 Natl Inst Stand & Technol, Div Opt Technol, Phys Lab, Gaithersburg, MD 20899 USA. Analog Digital Integrated Circuits, Longwood, FL 32750 USA. RP Eppeldauer, GP (reprint author), Natl Inst Stand & Technol, Div Opt Technol, Phys Lab, Gaithersburg, MD 20899 USA. NR 6 TC 5 Z9 5 U1 2 U2 7 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAY-JUN PY 2001 VL 106 IS 3 BP 577 EP 587 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 455CJ UT WOS:000170009700002 PM 27500036 ER PT J AU Chen, WN Fryrear, DW AF Chen, WN Fryrear, DW TI Aerodynamic and geometric diameters of airborne particles SO JOURNAL OF SEDIMENTARY RESEARCH LA English DT Article ID SETTLING VELOCITIES; SAND GRAINS; SIZE; AIR AB Settling velocity and aerodynamic equivalent diameter are properties of eolian particles that determine eolian transportation and deposition, This study establishes a relationship between geometric diameter and aerodynamic equivalent diameter. Glass spheres and five natural eolian deposits were dry-sieved to 15 size classes from 10 to 600 mum using an ultrasonic sieve, A vertical settling air tube (VSAT) was used to measure the average settling time and velocity, Terminal settling velocity and aerodynamic diameter were obtained by Stokes' Law and Newton's motion equation. Aerodynamic equivalent diameter varies as a power function of sieve diameter. Aerodynamic diameters are larger than geometric diameters for particles finer than 100 mum and smaller for particles coarser than 100 mum, Air settling decreases the spread of particle sizes as estimated from sieving, A shape factor (psi) is defined to show the relationship between aerodynamic equivalent diameter and geometric diameter. The measured psi varies as a natural logarithmic function of particle Reynolds number, not a constant as the existing literature suggested. C1 NOAA, Air Resources Lab, Natl Res Council, Res Triangle Pk, NC 27711 USA. Custom Prod & Consultants, Big Spring, TX 79720 USA. RP Chen, WN (reprint author), ALON USA Oil & Chem Co, POB 1311, Big Spring, TX 79721 USA. NR 28 TC 16 Z9 16 U1 0 U2 8 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 1731 E 71ST STREET, TULSA, OK 74136-5108 USA SN 1073-130X J9 J SEDIMENT RES JI J. Sediment. Res. PD MAY PY 2001 VL 71 IS 3 BP 365 EP 371 DI 10.1306/2DC4094A-0E47-11D7-8643000102C1865D PN A PG 7 WC Geology SC Geology GA 428JN UT WOS:000168458700004 ER PT J AU Zarr, RR Martinez-Fuentes, V Filliben, JJ Dougherty, BP AF Zarr, RR Martinez-Fuentes, V Filliben, JJ Dougherty, BP TI Calibration of thin heat flux sensors for building applications using ASTM C 1130 SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE building technology; calibration; guarded hot plate; heat flow meter; hear flux sensor; repeatability; thermal conductance; thermal insulation AB Calibration measurements of thin heat flux sensors for building applications are presented. The findings support the continued development of precision and bias statements for ASTM practice C 1130. Measurements have been conducted using a 1016 mm diameter guarded hot plate apparatus (Test Method C 177) from 10 degreesC to 50 degreesC and for a heat flux range of +/- 13 W/m(2). The option of using a 610 mm heat flow meter apparatus (Test Method C 518) to calibrate the heat flux sensors is also explored. Experimental designs are presented to compare test methods. evaluate which parameters affect the sensor output. and determine the functional relationship between the sensor output and applied heat flux. The study investigates two sizes of sensors fabricated by one manufacturer. Sensor equivalency. grouped by size. is evaluated to determine whether a calibration based on a subset of sensors will suffice or if extensive individual calibrations are needed. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Natl Meteorol Ctr, El Marques 76900, Queretaro, Mexico. RP Zarr, RR (reprint author), Natl Inst Stand & Technol, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 11 TC 3 Z9 3 U1 2 U2 3 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD MAY PY 2001 VL 29 IS 3 BP 293 EP 300 PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA 433RJ UT WOS:000168773300009 ER PT J AU Salomons, EA Ostashev, VE Clifford, SF Lataitis, RJ AF Salomons, EA Ostashev, VE Clifford, SF Lataitis, RJ TI Sound propagation in a turbulent atmosphere near the ground: An approach based on the spectral representation of refractive-index fluctuations SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID SPHERICAL WAVES; INTERFERENCE; BOUNDARY; MODEL AB A new. rigorous approach is presented for the computation of the fluctuating field of a monopole source in a nonrefracting, turbulent atmosphere above a ground surface. The time-averaged sound pressure level is considered. as well as statistical distributions of the sound pressure level, The computation is based on the Rytov solution of the wave equation for a turbulent medium, evaluated for the half-space above the ground surface. The solution takes into account the ground reflection of scattered waves, which has been neglected in previous work on this subject. The present approach is based on a Fourier-Stieltjes representation of refractive-index fluctuations, and makes use of a turbulent image atmosphere to account for the ground reflection of scattered waves, This approach is rigorous only for a rigid ground surface, but it is shown that it also yields a good approximation for a finite-impedance ground surface. The accuracy of the solution is demonstrated by comparison with results of numerical computations with the parabolic equation method for a turbulent atmosphere. The assumption of a nonrefracting atmosphere implies that direct application of the solution is limited to propagation over relatively small distances. However, this study can also be considered as a basis for a generalized solution for a downward refracting atmosphere, which can be applied for larger propagation distances. (C) 2001 Acoustical Society of America. C1 TNO, Inst Appl Phys, NL-2600 AD Delft, Netherlands. NOAA, Environm Technol Lab, Boulder, CO 80305 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. RP Salomons, EA (reprint author), TNO, Inst Appl Phys, POB 155, NL-2600 AD Delft, Netherlands. NR 34 TC 9 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 2001 VL 109 IS 5 BP 1881 EP 1893 DI 10.1121/1.1356021 PN 1 PG 13 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 431AC UT WOS:000168608700014 PM 11386543 ER PT J AU Ostashev, VE Salomons, EM Clifford, SF Lataitis, RJ Wilson, DK Blanc-Benon, P Juva, D AF Ostashev, VE Salomons, EM Clifford, SF Lataitis, RJ Wilson, DK Blanc-Benon, P Juva, D TI Sound propagation in a turbulent atmosphere near the ground: A parabolic equation approach SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID SURFACE-LAYER TURBULENCE; ACOUSTIC PROPAGATION; FLUCTUATIONS; COHERENCE; MODEL; PLANE; WAVES AB The interference of the direct wave from the point source to the receiver and the wave reflected from the impedance ground in a turbulent atmosphere is studied. A parabolic equation approach for calculating the sound pressure p at the receiver is formulated. Then, the parabolic equation is solved by the Rytov method yielding expressions for the complex phases of direct and ground-reflected waves. Using these expressions, a formula for the mean squared sound pressure < /p/(2)> is derived for the case of anisotropic spectra of temperature and wind velocity fluctuations. This formula contains the "coherence factor," which characterizes the coherence between direct and ground-reflected waves. It is shown that the coherence factor is equal to the normalized coherence function of a spherical sound wave for line-of-sight propagation. For the case of isotropic turbulence, this result allows one to obtain analytical formulas for < /p/(2)> for the Kolmogorov, Gaussian, and von Karman spectra of temperature and wind velocity fluctuations. Using these formulas, the effects of temperature and wind velocity fluctuations, and the effects of different spectra of these fluctuations on the mean squared sound pressure, are numerically studied. Also the effect of turbulent anisotropy on the interference of direct and ground reflected waves is numerically studied. Finally, it is shown that the mean squared sound pressure < /p/(2)> calculated for the von Karman spectrum of temperature fluctuations agrees well with experimental data obtained in a laboratory experiment, (C) 2001 Acoustical Society of America. C1 NOAA, Environm Technol Lab, Boulder, CO 80305 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. TNO, Inst Appl Phys, NL-2600 AD Delft, Netherlands. USA, Res Lab, Adelphi, MD 20783 USA. Ecole Cent Lyon, Ctr Acoust, Equipe LMFA, UMR CNRS 5509, F-69131 Ecully, France. RP NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80305 USA. EM vostashe@nmsu.edu RI Blanc-Benon, Philippe/H-1664-2016; Wilson, D. Keith/A-4687-2012 OI Wilson, D. Keith/0000-0002-8020-6871 NR 25 TC 13 Z9 13 U1 0 U2 5 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 EI 1520-8524 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 2001 VL 109 IS 5 BP 1894 EP 1908 DI 10.1121/1.1356022 PN 1 PG 15 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 431AC UT WOS:000168608700015 PM 11386544 ER PT J AU Wilson, DK Ostashev, VE AF Wilson, DK Ostashev, VE TI Statistical moments of the sound field propagating in a random, refractive medium near an impedance boundary SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID PARABOLIC EQUATION; ATMOSPHERE; TURBULENCE; MODEL; WAVE AB Propagation of a monochromatic sound field in a refractive and turbulent medium near an impedance boundary is considered. Starting from the parabolic equation for a moving medium and using the Markov approximation, a closed equation for the statistical moments of arbitrary order of the sound-pressure field is derived. Numerical methods for directly solving the first- and second-moment versions of this equation are formulated. The first-moment formulation is very similar to parabolic equations (PEs) that are now widely used to calculate sound fields for particular realizations of a random medium. The second-moment formulation involves a large, fringed tridiagonal matrix, which is solved using iterative refinement and Cholesky factorization. The solution is computationally intensive and currently restricted to low frequencies. As an example, the first and second moments are directly calculated for upwind and downwind propagation of a sound wave through a turbulent atmosphere. For these cases, predictions from the second-moment PE were statistically indistinguishable from the result of 40 random trials calculated with a standard Crank-Nicholson PE, although the second-moment PE yielded smoother results due to its ensemble-average nature. (C) 2001 Acoustical Society of America. C1 USA, Res Lab, AMSRL, CI,EP, Adelphi, MD 20783 USA. NOAA, Environm Technol Lab, Boulder, CO 80305 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. RP Wilson, DK (reprint author), USA, Res Lab, AMSRL, CI,EP, 2800 Powder Mill Rd, Adelphi, MD 20783 USA. RI Wilson, D. Keith/A-4687-2012 OI Wilson, D. Keith/0000-0002-8020-6871 NR 24 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 2001 VL 109 IS 5 BP 1909 EP 1922 DI 10.1121/1.1359239 PN 1 PG 14 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 431AC UT WOS:000168608700016 PM 11386545 ER PT J AU Goedecke, GH Wood, RC Auvermann, HJ Ostashev, VE Havelock, DI AF Goedecke, GH Wood, RC Auvermann, HJ Ostashev, VE Havelock, DI TI Spectral broadening of sound scattered by advecting atmospheric turbulence SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB Scattering and spectral broadening of a monochromatic sound wave by atmospheric turbulence that is flowing with a uniform constant horizontal wind is considered. The acoustic source and a detector are at rest and at different positions in a ground-fixed frame. Analytic expressions are derived for the sound pressure scattered to the detector by a single eddy. Since distances and the scattering angle change with time as the eddy flows through the scattering volume, the detector signal has time-dependent amplitude and frequency, for which general formulas are derived. A computer code is developed that calculates the scattered signal and its Fourier transform from a single eddy, or from a steady-state collection of eddies of many different scale lengths that represents isotropic homogeneous turbulence flowing with the wind. The code utilizes a time-shift algorithm that reduces the calculation time substantially. Several numerical results from this code are presented, including simulations of a recent experiment. The predicted spectral shape, including peak width and jaggedness, are in good agreement with experiment. (C) 2001 Acoustical Society of America. C1 New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Natl Res Council, Inst Microstruct Sci, Ottawa, ON K1A OR6, Canada. New Mexico State Univ, Klipsch Sch Elect & Comp Engn, Las Cruces, NM 88003 USA. RP Goedecke, GH (reprint author), Armstrong Atlantic State Univ, Dept Chem & Phys, Savannah, GA 31419 USA. NR 21 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 2001 VL 109 IS 5 BP 1923 EP 1934 DI 10.1121/1.1364489 PN 1 PG 12 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 431AC UT WOS:000168608700017 PM 11386546 ER PT J AU Rhee, YW Kim, HW Deng, Y Lawn, BR AF Rhee, YW Kim, HW Deng, Y Lawn, BR TI Contact-induced damage in ceramic coatings on compliant substrates: Fracture mechanics and design SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID QUASI-PLASTIC CERAMICS; BRITTLE COATINGS; STRENGTH DEGRADATION; HERTZIAN CONTACTS; LAYER STRUCTURES; DENTAL CERAMICS; SILICON-NITRIDE; GLASS-CERAMICS; CYCLIC FATIGUE; INDENTATION AB Simple explicit relations are presented for the onset of competing fracture modes in ceramic coatings on compliant substrates from Hertzian-like contacts. Special attention is given to a deleterious mode of radial cracking that initiates at the lower coating surface beneath the contact, in addition to traditional cone cracking and quasiplasticity in the near-contact area. The critical load relations are expressed in terms of well-documented material parameters (elastic modulus, toughness, hardness, and strength) and geometrical parameters (coating thickness and sphere radius). Data from selected glass, Al2O3 and ZrO2 coating materials on polycarbonate substrates are used to demonstrate the validity of the relations. The formulation provides a basis for designing ceramic coatings with optimum damage resistance. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Korea Adv Inst Sci & Technol, Dept Mat Sci & Engn, Taejon 305701, South Korea. NR 38 TC 74 Z9 77 U1 0 U2 5 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 2001 VL 84 IS 5 BP 1066 EP 1072 PG 7 WC Materials Science, Ceramics SC Materials Science GA 431XM UT WOS:000168657100025 ER PT J AU Munro, RG AF Munro, RG TI Effective medium theory of the porosity dependence of bulk moduli SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID YOUNG MODULUS; MECHANICAL-PROPERTIES; ALUMINA AB Effective medium theory is used to obtain a closed- form expression for the porosity dependence of the bulk moduli of ceramics. The theory is illustrated with an application to data for high-purity alumina that spans a volume fraction of porosity ranging from 0.5% to 90%. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Munro, RG (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. NR 30 TC 20 Z9 20 U1 0 U2 4 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 2001 VL 84 IS 5 BP 1190 EP 1192 PG 3 WC Materials Science, Ceramics SC Materials Science GA 431XM UT WOS:000168657100049 ER PT J AU Yi, CX Davis, KJ Berger, BW Bakwin, PS AF Yi, CX Davis, KJ Berger, BW Bakwin, PS TI Long-term observations of the dynamics of the continental planetary boundary layer SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID ATMOSPHERIC CO2; CARBON-DIOXIDE; WIND PROFILER; BOREAL FOREST; MIXED-LAYER; ENTRAINMENT; RADAR; MODEL; INVERSION; BUDGET AB Time series of mixed layer depth, z(i), and stable boundary layer height from March through October of 1998 are derived from a 915-MHz boundary layer profiling radar and CO2 mixing ratio measured from a 447-m tower in northern Wisconsin. Mixed layer depths from the profiler are in good agreement with radiosonde measurements. Maximum z(i) occurs in May, coincident with the maximum daytime surface sensible heat flux. Incoming radiation is higher in June and July, but a greater proportion is converted to latent heat by photosynthesizing vegetation. An empirical relationship between z(i) and the square root of the cumulative surface virtual potential temperature flux is obtained (r(2) = 0.98) allowing estimates of z(i) from measurements of virtual potential temperature flux under certain conditions. In fair-weather conditions the residual mixed layer top was observed by the profiler on several nights each month. The synoptic mean vertical velocity (subsidence rate) is estimated from the temporal evolution of the residual mixed layer height during the night. The influence of subsidence on the evolution of the mixed, stable, and residual layers is discussed. The CO2 jump across the inversion at night is also estimated from the tower measurements. C1 Univ Minnesota, Dept Soil Water & Climate, St Paul, MN 55108 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Yi, CX (reprint author), Penn State Univ, Dept Meteorol, 416 Walker Bldg, University Pk, PA 16802 USA. RI Yi, Chuixiang/A-1388-2013 NR 34 TC 66 Z9 67 U1 0 U2 11 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 MAY PY 2001 VL 58 IS 10 BP 1288 EP 1299 DI 10.1175/1520-0469(2001)058<1288:LTOOTD>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 430EZ UT WOS:000168562700006 ER PT J AU Nieh, MP Glinka, CJ Krueger, S Prosser, RS Katsaras, J AF Nieh, MP Glinka, CJ Krueger, S Prosser, RS Katsaras, J TI SANS study of the structural phases of magnetically alignable lanthanide-doped phospholipid mixtures SO LANGMUIR LA English DT Article ID ANGLE NEUTRON-SCATTERING; HIGH-RESOLUTION NMR; SOLID-STATE NMR; LIPID BILAYERS; FLUID MEMBRANES; MICELLES; MODEL; POLYPEPTIDES; BICELLES; SYSTEM AB The structural phases of magnetically alignable lipid mixtures were investigated as a function of temperature and lipid concentration using small-angle neutron scattering (SANS). Two systems were examined: (a) an aqueous mixture of DMPC (dimyristoyl phosphatidylcholine) and DHPC (dihexanoyl phosphatidylcholine) lipids doped with Tm3+ ions resulting in the positive alignment of the system with the applied magnetic field and (b) the above aqueous Tm3+ doped lipid mixture containing a negatively charged lipid, DMPG (dimyristoylphosphatidylglycerol). For both systems, three different scattering patterns were observed corresponding to distinct structural phases at specific temperatures and lipid concentrations. At 45 degreesC and a lipid concentration of >0.05 g/mL, the high-viscosity liquid crystalline phase was found to be a perforated and possibly undulating lamellar phase consistent with NMR results. Upon dilution ( < 0.05 g/mL) at the same temperature (45 degreesC), the perforated lamellar phase transformed into a unilamellar vesicular phase, in which the bilayers may also be perforated. Below about 25 degreesC, the viscosity decreases considerably and the scattering data suggest that the lamellae present at higher temperatures break up into smaller entities characterized by the bicellar morphology proposed previously for the nondoped system. The structural dimensions of the vesicular and bicellar phases have been determined as a function of lipid concentrations from the SANS data. In the lamellar phase, the influence of Tm3+ ions and DMPG on bilayer structure (e.g., lamellar repeat spacing, bilayer rigidity, and magnetic alignment) were also investigated. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Penn State Univ, Dept Mat Sci, University Pk, PA 16802 USA. Kent State Univ, Dept Chem, Kent, OH 44242 USA. Kent State Univ, Inst Liquid Crystal, Kent, OH 44242 USA. Natl Res Council, Chalk River Labs, Steacie Inst Mol Sci, Neutron Program Mat Res, Chalk River, ON, Canada. RP Nieh, MP (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. OI Nieh, Mu-Ping/0000-0003-4462-8716; Katsaras, John/0000-0002-8937-4177 NR 32 TC 117 Z9 119 U1 4 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 1 PY 2001 VL 17 IS 9 BP 2629 EP 2638 DI 10.1021/la001567w PG 10 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 426XD UT WOS:000168373000017 ER PT J AU Wang, H Composto, RJ Hobbie, EK Han, CC AF Wang, H Composto, RJ Hobbie, EK Han, CC TI Multiple lateral length scales in phase-separating thin-film polymer blends SO LANGMUIR LA English DT Article ID DIRECTED SPINODAL DECOMPOSITION; BINARY-MIXTURES AB The interplay of phase separation, preferential wetting, and capillary instability in thin-film polymer blends is investigated using composition-profiling and surface-imaging techniques. The phase-separating films exhibit a unique morphology with two evolving lateral length scales at both the free film surface and the interface between the wetting and nonwetting layers. The short-wavelength mode shows power-law growth at both the free film surface and the interface, but with a smaller growth exponent at the surface, implying slower kinetics. The long-wavelength mode shows two power-law growth regimes separated by a plateau. C1 Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. Univ Penn, Lab Res Struct Matter, Philadelphia, PA 19104 USA. RP NIST, Div Polymers, Gaithersburg, MD 20899 USA. EM hao.wang@nist.gov RI Hobbie, Erik/C-8269-2013 NR 20 TC 18 Z9 18 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 1 PY 2001 VL 17 IS 9 BP 2857 EP 2860 DI 10.1021/la001570f PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 426XD UT WOS:000168373000049 ER PT J AU Theilacker, GH Shen, W AF Theilacker, GH Shen, W TI Evaluating growth of larval walleye pollock, Theragra chalcogramma, using cell cycle analysis SO MARINE BIOLOGY LA English DT Article ID RNA-DNA RATIO; DRUM SCIAENOPS-OCELLATUS; COD GADUS-MORHUA; ENGRAULIS-MORDAX; NUTRITIONAL CONDITION; NORTHERN ANCHOVY; ATLANTIC COD; SHELIKOF-STRAIT; FLOW-CYTOMETRY; MARINE FISHES AB Cell cycle analysis of muscle cell division rates offers a new and efficient technique to analyze growth of larval fish. Using this approach, growth of larval walleye pollock was estimated by determining cell proliferation rates, reasoning that growth during early life stages is probably attributed to increases in cell number rather than to increases in cell size. Characteristic patterns of brain and muscle cell division rates were produced in larval walleye pollock by manipulating their diet in the laboratory. The fraction of dividing muscle cells and, to a lesser extent, the fraction of dividing brain cells were direct indicators of fast and slow growth. A model was produced to estimate average growth rate from the fraction of dividing muscle cells. We developed a simple method for preparing and storing the muscle tissue that ensures nucleic acid stability for subsequent analyses and permits sampling in the field. We envision that the cell cycle methodology will have on-site applications, presenting an opportunity to attain real-time estimates of larval fish growth at sea. Determining the proportion of first-feeding larvae with a high fraction of dividing muscle cells may yield a means for predicting the proportion of fast-growing fish, i.e., the potential survivors. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. Univ Washington, Dept Pathol, Seattle, WA 98195 USA. RP Theilacker, GH (reprint author), 2314 N 37th St, Seattle, WA 98103 USA. NR 59 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD MAY PY 2001 VL 138 IS 5 BP 897 EP 907 PG 11 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 439HD UT WOS:000169104300002 ER PT J AU Brill, R Swimmer, Y Taxboel, C Cousins, K Lowe, T AF Brill, R Swimmer, Y Taxboel, C Cousins, K Lowe, T TI Gill and intestinal Na+-K+ ATPase activity, and estimated maximal osmoregulatory costs, in three high energy-demand teleosts: yellowfin tuna (Thunnus albacares), skipjack tuna (Katsuwonus pelamis), and dolphin fish (Coryphaena hippurus) SO MARINE BIOLOGY LA English DT Article ID TILAPIA OREOCHROMIS-MOSSAMBICUS; STANDARD METABOLIC-RATE; TROUT SALMO-GAIRDNERI; FRESH-WATER; SEAWATER ACCLIMATION; OXYGEN-CONSUMPTION; RAINBOW-TROUT; CARBONIC-ANHYDRASE; EURYHALINE TELEOST; ENZYME-ACTIVITIES AB We hypothesize that the morpho-physiological adaptations that permit tunas to achieve maximum metabolic rates (MMR) that are more than double those of other active fishes should result in high water and ion flux rates across the gills and concomitant high osmoregulatory costs. The high standard metabolic rates (SMR) of tunas and dolphin fish may, therefore, be due to the elevated rates of energy expenditure for osmoregulation (i.e. teleosts capable of achieving exceptionally high MMR necessarily have SMR). Previous investigators have suggested a link between activity patterns and osmoregulatory costs based on Na+-K+ ATPase activity in the gills of active epipelagic and sluggish deepsea fishes. Based on these observations, we conclude that high-energy-demand fishes (i.e, tunas and dolphin fish) should have exceptionally elevated gill and intestinal Na+-K+ ATPase activity reflecting their elevated rates of salt and water transfer. To test this idea and estimate osmoregulatory costs, we measured Naf-Kf ATPase activity (V,,,) in homogenates of frozen samples taken from the gills and intestines of skipjack and yellowfin tunas, and the gills of dolphin fish. As a check of our procedures, we made similar measurements using tissues from hybrid red tilapia (Oreochromis mossambicus x O. niloticus). Contrary to our supposition, we found no difference in Na+-K+ ATPase activity per unit mass of gill or intestine in these four species. We estimate the cost of osmoregulation to be at most 9% and 13% of the SMR in skipjack tuna and yellowfin tuna, respectively. Our results, therefore, do not support either of our original suppositions, and the cause(s) underlying the high SMR of tunas and dolphin fish remain unexplained. C1 Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Joint Inst Marine & Atmospher Res, Pelag Fisheries Res Program, Honolulu, HI 96822 USA. RP Brill, R (reprint author), NOAA, Natl Marine Fisheries Serv, 2570 Dole St, Honolulu, HI 96822 USA. NR 90 TC 18 Z9 18 U1 2 U2 18 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD MAY PY 2001 VL 138 IS 5 BP 935 EP 944 DI 10.1007/s002270000514 PG 10 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 439HD UT WOS:000169104300005 ER PT J AU Rogers, JS Hare, JA Lindquist, DG AF Rogers, JS Hare, JA Lindquist, DG TI Otolith record of age, growth, and ontogeny in larval and pelagic juvenile Stephanolepis hispidus (Pisces : Monacanthidae) SO MARINE BIOLOGY LA English DT Article ID FLOUNDER PSEUDOPLEURONECTES-AMERICANUS; BLUEFISH POMATOMUS-SALTATRIX; SOUTH-ATLANTIC BIGHT; COHORT DYNAMICS; REEF FISH; MICROSTRUCTURE; SIZE; WINTER; METAMORPHOSIS; INCREMENTS AB Juveniles of the planehead filefish Stephanolepis hispidus (Pisces: Monacanthidae) (Linnaeus, 1766) are a major component of the Sargassum spp, community, yet little is known of their ecology. In this study, the otolith record of age, growth, and ontogeny in S. hispidus was examined. Juveniles caught off Beaufort Inlet, North Carolina (USA) on 30 June 1996 were marked with alizarin complexone and reared in a flow-through, outdoor tank for up to 19 days. Examination of marked otoliths at several time intervals showed that increment formation was not significantly different than one increment per day, and thus, increment number was used to estimate age. Depth-distribution, morphology, and meristics of larvae and juveniles collected (1990-1992) between Cape Remain, South Carolina, and Cape Hatteras, North Carolina, were examined to identify the timing of the larval to juvenile transition. All indicators suggested the transition occurred between 17 and 20 days. Mean otolith increment widths exhibited a marked change at about 20 days, coinciding with the timing of the larval to juvenile transition and a change in the depth distribution from bottom to surface waters. Increment width of individual juveniles, however, did not exhibit the same pattern; only 40% conformed to the pattern identified for all fish. Thus, the record of the larval to juvenile transition is clear at the population level, but unresolved at the individual level. C1 NOAA, Natl Ocean Serv, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. Univ N Carolina, Dept Biol Sci, Wilmington, NC 28516 USA. Univ N Carolina, Ctr Marine Sci, Wilmington, NC 28516 USA. RP Hare, JA (reprint author), NOAA, Natl Ocean Serv, Ctr Coastal Fisheries & Habitat Res, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 44 TC 18 Z9 20 U1 1 U2 10 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD MAY PY 2001 VL 138 IS 5 BP 945 EP 953 DI 10.1007/s002270000521 PG 9 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 439HD UT WOS:000169104300006 ER PT J AU Pank, M Stanhope, M Natanson, L Kohler, N Shivji, M AF Pank, M Stanhope, M Natanson, L Kohler, N Shivji, M TI Rapid and simultaneous identification of body parts from the morphologically similar sharks Carcharhinus obscurus and Carcharhinus plumbeus (Carcharhinidae) using multiplex PCR SO MARINE BIOTECHNOLOGY LA English DT Article DE Carcharhinus; fins; genetic identification; ITS2; multiplex PCR; sharks ID SEQUENCES AB Many commercially exploited carcharhinid sharks are difficult to identify to species owing to extensive morphological similarities. This problem is severely exacerbated when it comes to identifying detached shark fins, and the finless and headless shark carasses typically sold in markets. To assist in the acquisition of urgently needed conservation and management data on shark catch and trade, we have developed a highly streamlined approach based on multiplex polymerase chain reaction (PCR) that uses species-specific primers derived from nuclear ribosomal ITS2 sequences to achieve rapid species identification of shark body parts. Here we demonstrate the utility of this approach for identifying fins and flesh from two globally distributed, morphologically very similar carcharhinid sharks (Carcharhinus obscurus and Carcharhinus plumbeus) intensively targeted in fisheries worldwide, and often confused for each other even as whole animals. The assay is conducted in a 4-primer multiplex format that is structured to simultaneously achieve the following efficiency and cost-reduction objectives: it requires only a single-tube amplification reaction for species diagnosis, it incorporates an internal positive control to allow detection of false-negative results, and it is novel in that it allows species identification even when DNAs from two species are combined in the same tube during the PCR reaction. The latter innovation reduces the required effort for screening a set of unknown samples by 50%. The streamlined approach illustrated here should be amenable for use in a shark conservation and management context where large numbers of samples typically need to be screened; the approach shown may also provide a model for a rapid diagnostic method applicable to species identification in general. C1 Nova SE Univ, Oceanog Ctr, Dania Beach, FL 33004 USA. Nova SE Univ, Guy Harvey Res Inst, Dania Beach, FL 33004 USA. Queens Univ, Belfast, Antrim, North Ireland. NOAA, Natl Marine Fisheries Serv, Narragansett, RI 02882 USA. RP Shivji, M (reprint author), Nova SE Univ, Oceanog Ctr, 8000 N Ocean Dr, Dania Beach, FL 33004 USA. NR 26 TC 50 Z9 55 U1 0 U2 12 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1436-2228 J9 MAR BIOTECHNOL JI Mar. Biotechnol. PD MAY-JUN PY 2001 VL 3 IS 3 BP 231 EP 240 DI 10.1007/s101260000071 PG 10 WC Biotechnology & Applied Microbiology; Marine & Freshwater Biology SC Biotechnology & Applied Microbiology; Marine & Freshwater Biology GA 449EU UT WOS:000169672000005 PM 14961360 ER PT J AU Buonaccorsi, VP McDowell, JR Graves, JE AF Buonaccorsi, VP McDowell, JR Graves, JE TI Reconciling patterns of inter-ocean molecular variance from four classes of molecular markers in blue marlin (Makaira nigricans) SO MOLECULAR ECOLOGY LA English DT Article DE computer simulation; microsatellite DNA; mtDNA; population genetics; population structure; power ID FINITE ISLAND MODEL; COD GADUS-MORHUA; GLOBAL POPULATION-STRUCTURE; MITOCHONDRIAL-DNA MARKERS; GENE FLOW; MICROSATELLITE LOCI; MUTATIONAL PROCESSES; STEPWISE MUTATION; ALLOZYME MARKERS; RESTRICTION DATA AB Different classes of molecular markers occasionally yield discordant views of population structure within a species. Here, we examine the distribution of molecular variance from 14 polymorphic loci comprising four classes of molecular markers within approximate to 400 blue marlin individuals (Makaira nigricans). Samples were collected from the Atlantic and Pacific Oceans over 5 years. Data from five hypervariable tetranucleotide microsatellite loci and restriction fragment length polymorphism (RFLP) analysis of whole molecule mitochondrial DNA (mtDNA) were reported and compared with previous analyses of allozyme and single-copy nuclear DNA (scnDNA) loci. Temporal variance in allele frequencies was nonsignificant in nearly all cases. Mitochondrial and microsatellite loci revealed striking phylogeographic partitioning among Atlantic and Pacific Ocean samples. A large cluster of alleles was present almost exclusively in Atlantic individuals at one microsatellite locus and for mtDNA, suggesting that, if gene now occurs, it is likely to be unidirectional from Pacific to Atlantic oceans. Mitochondrial DNA inter-ocean divergence (F-ST) was almost four times greater than microsatellite or combined nuclear divergences including allozyme and scnDNA markers. Estimates of N(e)u varied by five orders of magnitude among marker classes. Using mathematical and computer simulation approaches, we show that substantially different distributions of F-ST are expected from marker classes that differ in mode of inheritance and rate of mutation, without influence of natural selection or sex-biased dispersal. Furthermore, divergent F-ST values can be reconciled by quantifying the balance between genetic drift, mutation and migration. These results illustrate the usefulness of a mitochondrial analysis of population history, and relative precision of nuclear estimates of gene flow based on a mean of several loci. C1 Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. RP Buonaccorsi, VP (reprint author), Natl Marine Fisheries Serv, 8604 La Jolla Shores Dr, La Jolla, CA 92037 USA. NR 79 TC 107 Z9 122 U1 1 U2 12 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD MAY PY 2001 VL 10 IS 5 BP 1179 EP 1196 DI 10.1046/j.1365-294X.2001.01270.x PG 18 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 432LJ UT WOS:000168692900010 PM 11380876 ER PT J AU Cinzano, P Falchi, F Elvidge, CD AF Cinzano, P Falchi, F Elvidge, CD TI Naked-eye star visibility and limiting magnitude mapped from DMSP-OLS satellite data SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE scattering; atmospheric effects; light pollution; site testing ID NIGHT-SKY BRIGHTNESS; OPERATIONAL LINESCAN SYSTEM; HUMAN-SETTLEMENTS; MAUNA-KEA; LIGHT; EXTINCTION; EMISSIONS; SITES AB We extend the method introduced by Cinzano et al. to map the artificial sky brightness in large territories from DMSP satellite data, in order to map the naked-eye star visibility and telescopic limiting magnitudes. For these purposes we take into account the altitude of each land area from GTOPO30 world elevation data, the natural sky brightness in the chosen sky direction, based on Garstang modelling, the eye capability with the naked eye or a telescope, based on the Schaefer and Garstang approach, and the stellar extinction in the visual photometric band. For near-zenith sky directions we also take into account screening by terrain elevation. Maps of naked-eye star visibility and telescopic limiting magnitudes are useful for quantifying the capability of the population to perceive our Universe, evaluating the future evolution, making cross-correlations with statistical parameters, and recognizing areas where astronomical observations or popularization can still acceptably be made. We present, as an application, maps of naked-eye star visibility and total sky brightness in the V band in Europe at the zenith with a resolution of approximately 1 km. C1 Univ Padua, Dipartimento Astron, I-35122 Padua, Italy. NOAA, Natl Geophys Data Ctr, Off Director, Boulder, CO 80303 USA. RP Cinzano, P (reprint author), Univ Padua, Dipartimento Astron, Vicolo Osservatorio 5, I-35122 Padua, Italy. RI Elvidge, Christopher/C-3012-2009 NR 65 TC 28 Z9 28 U1 0 U2 13 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 1 PY 2001 VL 323 IS 1 BP 34 EP 46 DI 10.1046/j.1365-8711.2001.04213.x PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 434JE UT WOS:000168810700006 ER PT J AU Baranyi, T Gyori, L Ludmany, A Coffey, HE AF Baranyi, T Gyori, L Ludmany, A Coffey, HE TI Comparison of sunspot area data bases SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE methods : data analysis; sunspots ID IRRADIANCE; CONTRAST; DECAY AB Sunspot area measurements play an important role in the studies of sunspot groups and variations in solar irradiance. However, the measured areas may be burdened with systematic and random errors, which may affect the results in these fields. Mainly the total solar irradiance models can be improved by using more precise area data. In order to choose the most appropriate area data for a given study or create a homogeneous composite area data base, there is a need to compare the sunspot areas provided by different observatories. In this study we statistically investigated all the available corrected sunspot area data bases for the years 1986 and 1987. We find that the photographic data bases are in good agreement with each other but there are important systematic differences between the photographic and sunspot drawings data bases. We give the characteristic parameters for the systematic and random errors as well as the possible reasons for them. C1 Hungarian Acad Sci, Heliophys Observ, H-4010 Debrecen, Hungary. Heliophys Observ, Gyula Observing Stn, H-5701 Gyula, Hungary. NOAA, NESDIS, NGDC, Solar Terr Phys Div EGC2, Boulder, CO 80303 USA. RP Baranyi, T (reprint author), Hungarian Acad Sci, Heliophys Observ, POB 30, H-4010 Debrecen, Hungary. NR 32 TC 32 Z9 32 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 1 PY 2001 VL 323 IS 1 BP 223 EP 230 DI 10.1046/j.1365-8711.2001.04195.x PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 434JE UT WOS:000168810700022 ER PT J AU Muir, WD Smith, SG Williams, JG Hockersmith, EE Skalski, JR AF Muir, WD Smith, SG Williams, JG Hockersmith, EE Skalski, JR TI Survival estimates for migrant yearling chinook salmon and steelhead tagged with passive integrated transponders in the lower Snake and lower Columbia rivers, 1993-1998 SO NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT LA English DT Article ID PACIFIC SALMON; RATES AB Precise, up-to-date survival estimates for salmonids that migrate through reservoirs, hydroelectric dams, and free-flowing sections of the Snake and Columbia rivers are essential to develop effective strategies for recovering depressed stocks. To provide this information, survival was estimated for yearling chinook salmon Oncorhynchus tshawytschu and steelhead O. mykiss with passive integrated transponder (PIT) tags that migrated through Snake River dams and reservoirs from 1993 through 1998. A multiple-recapture model for single release groups was used to estimate survival from detections of PIT-tagged fish at dams. The stretch of river over which survival was estimated varied between years, depending on the release site, the number of dams with the capability to detect and rerelease PIT-tagged fish back to the river, the total number of fish marked, and the efficiency of detecting PIT-tagged fish at each dam. Precision of survival estimates varied with the number of fish PIT-tagged and released and the amount of spill at dams with PIT-tag detectors. When spill levels were high, detection probabilities were lower, as was precision. Mortality at bypass outfall sites was not significant at any Snake River dam investigated. Estimated annual average per-project (combined reservoir and dam passage) survival ranged from 86% to 94% for yearling chinook salmon and from 88% to 92% for steelhead. Survival estimates were higher for both species in years when spill was used specifically to pass fish through nonturbine routes. Over the same stretches of river in years with similar flow conditions from 1970 through 1975, per-project survival estimates typically averaged 57-71% for yearling chinook salmon and 77-90% for steelhead. From 1993 to 1998, survival estimates for fish released from Snake River basin hatcheries to the Lower Granite Dam tailrace indicated that substantial smolt mortality occurred before fish entered the hydropower system. For each hatchery, estimated survival varied each year, and estimates from different hatcheries to Lower Granite Dam varied inversely with the distance fish traveled. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fish Ecol Div, Seattle, WA 98112 USA. Univ Washington, Columbia Basin Res Sch Aquat & Fishery Sci, Seattle, WA 98195 USA. RP Muir, WD (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fish Ecol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. OI Skalski, John/0000-0002-7070-2505 NR 36 TC 66 Z9 66 U1 0 U2 13 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0275-5947 J9 N AM J FISH MANAGE JI North Am. J. Fish Manage. PD MAY PY 2001 VL 21 IS 2 BP 269 EP 282 DI 10.1577/1548-8675(2001)021<0269:SEFMYC>2.0.CO;2 PG 14 WC Fisheries SC Fisheries GA 529FJ UT WOS:000174289100001 ER PT J AU Williams, JG Smith, SG Muir, WD AF Williams, JG Smith, SG Muir, WD TI Survival estimates for downstream migrant yearling juvenile salmonids through the Snake and Columbia rivers hydropower system, 1966-1980 and 1993-1999 SO NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT LA English DT Article ID CHINOOK SALMON AB This paper examines average annual survival of juvenile spring-summer chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss during migration through the hydropower system of the Snake and Columbia rivers from 1966 to 1980 and 1993 to 1999. In each year, survival was estimated from observations of marked fish in a portion of the hydropower system corridor. We expanded these estimates to calculate an annual estimate of survival over the entire system (head of uppermost reservoir to tailrace of lowermost dam). Temporal changes in the hydropower system were compared with trends in estimated survival to evaluate the effects of dams on survival of downstream migrants. When only four dams were in place (1966-1967), estimates of survival through the hydropower system were 32-56%. Four additional dams were constructed between 1968 and 1975. Survival estimates during the 1970s typically were 10-30% for spring-summer chinook salmon, but less than 3% in the drought years of 1973 and 1977. From 1993 to 1999, after structural and operational changes in the hydropower system, survival estimates of spring-summer chinook salmon and steelhead ranged from 31% to 59%. Smolt-to-adult return rates of Snake River wild spring-summer chinook salmon from the middle to late 1960s generally exceeded 4% but decreased during the 1970s. Although survival through the hydropower system in the 1990s is substantially greater than that in the 1970s, adult return rates in the 1990s have remained low. Thus, in the 1990s, the cause of the continuing low adult return rates does not seem to be related to direct mortality of downstream migrant fish within the hydropower system. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fish Ecol Div, Natori, Miyagi 98112, Japan. RP Williams, JG (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fish Ecol Div, 2725 Montlake Blvd E, Natori, Miyagi 98112, Japan. NR 22 TC 39 Z9 41 U1 0 U2 12 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0275-5947 J9 N AM J FISH MANAGE JI North Am. J. Fish Manage. PD MAY PY 2001 VL 21 IS 2 BP 310 EP 317 DI 10.1577/1548-8675(2001)021<0310:SEFDMY>2.0.CO;2 PG 8 WC Fisheries SC Fisheries GA 529FJ UT WOS:000174289100004 ER PT J AU Ryan, BA Ferguson, JW Ledgerwood, RD Nunnallee, EP AF Ryan, BA Ferguson, JW Ledgerwood, RD Nunnallee, EP TI Detection of passive integrated transponder tags from juvenile salmonids on piscivorous bird colonies in the Columbia River basin SO NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT LA English DT Article ID SYSTEM; PIT AB We modified 400-kHz passive integrated transponder (PIT) tag detection equipment, previously used in water, to detect PIT tags in piscivorous bird-nesting areas in the Columbia River basin. Two land-based recovery mechanisms were developed: a flat-plate antenna that was drawn over the surface of bird-nesting areas with a four-wheel-drive vehicle and a pole-mounted antenna that was passed by hand over smaller nesting areas. In 1998 and 1999, we detected more than 100,000 unique PIT tag codes by the use of the flat-plate antenna, and in 1999, we detected more than 10,000 unique PIT tag codes by the use of the pole-mounted antenna. Codes were detected for every release year since 1987, the first year that salmonids were marked with PIT tags in the Columbia River basin; however, the majority of tag codes came from juveniles marked for the 1999 migration year (>50,000 tag codes recovered). In 2000, researchers in the Columbia River basin changed to a 134.2-kHz PIT tag, in accordance with guidelines from the International Standards Organization (ISO). We are adapting the land-based apparatus to detect ISO tags, which will provide information on management issues critical to recovering salmonid stocks listed under the Federal Endangered Species Act. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fish Ecol Div, Seattle, WA 98112 USA. RP Ryan, BA (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fish Ecol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 14 TC 10 Z9 12 U1 0 U2 1 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0275-5947 J9 N AM J FISH MANAGE JI North Am. J. Fish Manage. PD MAY PY 2001 VL 21 IS 2 BP 417 EP 421 DI 10.1577/1548-8675(2001)021<0417:DOPITT>2.0.CO;2 PG 5 WC Fisheries SC Fisheries GA 529FJ UT WOS:000174289100016 ER PT J AU Cahn, JW Nabarro, FRN AF Cahn, JW Nabarro, FRN TI Thermal activation under shear SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID KINKED SCREW DISLOCATIONS; ANDRADE CREEP; BCC LATTICE; FLOW-STRESS AB Becker in 1925 and Mott and Nabarro in 1948 gave different expressions for the stress dependence of activation energy for shear in the limit when the stress approaches that at which plastic deformation can occur without thermal activation. We show that, when allowance is made for the inevitable elastic nonlinearity in the activated state, Becker's model leads to the same dependence as that of Mott and Nabarro. This limiting expression is likely to be valid in many, but not all, processes of thermally activated plastic deformation. Following Clough and Simmons, we explore definitions of activation volumes under a general stress that are tensors and represent the volume integral of the strain which occurs during the process of activation. We then consider the influence of the sharpness of the dependence of the strain rate on the applied stress. Activation of plastic deformation at one site sheds loads on to other sites which may then activate athermally, producing a multiplication factor which is itself stress dependent and may diverge before the applied stress reaches that at which activation occurs without thermal assistance. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Witwatersrand, Condensed Matter Phys Res Unit, ZA-2050 Wits, Johannesburg, South Africa. CSIR, Div Mat Sci & Technol, ZA-0001 Pretoria, South Africa. RP Cahn, JW (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 31 TC 37 Z9 37 U1 3 U2 17 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD MAY PY 2001 VL 81 IS 5 BP 1409 EP 1426 PG 18 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 433KC UT WOS:000168757700023 ER PT J AU Glasgow, HB Burkholder, JM Morton, SL Springer, J AF Glasgow, HB Burkholder, JM Morton, SL Springer, J TI A second species of ichthyotoxic Pfiesteria (Dinamoebales, Dinophyceae) SO PHYCOLOGIA LA English DT Article; Proceedings Paper CT 9th International Conference on Harmful Algal Blooms CY FEB 07-11, 2000 CL HOBART, AUSTRALIA ID FISH KILLS; PISCICIDA DINOPHYCEAE; TOXIC DINOFLAGELLATE; LIFE-CYCLE; COMPLEX; ESTUARY; MANAGEMENT; BEHAVIOR; IMPACTS; RIVER AB A second toxic species within the family Pfiesteriaceae, Pfiesteria shumwayae Glas.-ow & Burkholder sp. nov., is described from the New River Estuary and the Neuse Estuary of the Albemarle-Pamlico Estuarine Ecosystem, USA. The species is polymorphic and multiphasic, with flagellated, amoeboid and cyst stages. The flagellated zoospores (diameter 8-24 mum) have permanently condensed chromosomes (mesokaryotic nucleus); a chrysophyte-like cyst (diameter 6-25 mum) With organic scales and bracts; and thin thecal plates arranged in a Kofoidian series of Po, cp, X, 4', 1a, 6", 6c, 4s, 5"', 2''''. The benthic filopodial (filose), lobopodial (lobose) and rhizopodial amoeboid stages (5-250 mum) have an outer covering that ranges from rough to smooth in texture, depending on the stage of origin and the prey source, Pfiesteria shumwayae amoebae have a normal eukaryote nucleus and cysts of multiple sizes (diameter 4-25 mum) With a reticulate outer covering, Toxic strains of the two Pfiesteria species have overlapping distributions in the mid-Atlantic and southeastern United States and Scandinavia, with toxic P. shumwayae also having been verified from New Zealand. Pfiesteria shumwayae is similar to P. piscicida in its complex life cycle, general nutrition, attraction to live fish prey, and ichthyotoxic activity that is stimulated by the presence of live fish or their fresh tissues and excreta. However, it can be distinguished from P. piscicida morphologically by having six precingular plates and a four-sided I a plate, as well as genetically, on the basis of its 18S ribosomal DNA sequence. C1 N Carolina State Univ, Ctr Appl Aquat Ecol, Raleigh, NC 27606 USA. NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Marine Biotoxin Program, Charleston, SC 29412 USA. RP Glasgow, HB (reprint author), N Carolina State Univ, Ctr Appl Aquat Ecol, 620 Hutton St,Suite 104, Raleigh, NC 27606 USA. EM howard_glasgow@ncsu.edu NR 55 TC 54 Z9 56 U1 1 U2 9 PU INT PHYCOLOGICAL SOC PI LAWRENCE PA NEW BUSINESS OFFICE, PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0031-8884 J9 PHYCOLOGIA JI Phycologia PD MAY PY 2001 VL 40 IS 3 BP 234 EP 245 DI 10.2216/i0031-8884-40-3-234.1 PG 12 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 465MG UT WOS:000170592300006 ER PT J AU Anderson, DM McFadden, GB Wheeler, AA AF Anderson, DM McFadden, GB Wheeler, AA TI A phase-field model with convection: sharp-interface asymptotics SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article DE phase-field; convection; solidification; sharp-interface analysis ID DENDRITIC GROWTH; UNEQUAL CONDUCTIVITIES; CRYSTAL-GROWTH; SOLIDIFICATION; STABILITY; TRANSITIONS; KINETICS; ENERGY; FLUID; ALLOY AB We have previously developed a phase-field model of solidification that includes convection in the melt [Physica D 135 (2000) 175]. This model represents the two phases as viscous liquids, where the putative solid phase has a viscosity much larger than the liquid phase. The object of this paper is to examine in detail a simplified version of the governing equations for this phase-field model in the sharp-interface limit to derive the interfacial conditions of the associated free-boundary problem. The importance of this analysis is that it reveals the underlying physical mechanisms built into the phase-field model in the context of a free-boundary problem and, in turn, provides a further validation of the model. In equilibrium, we recover the standard interfacial conditions including the Young-Laplace and Clausius-Clapeyron equations that relate the temperature to the pressures in the two bulk phases, the interface curvature and material parameters. In nonequilibrium, we identify boundary conditions associated with classical hydrodynamics, such as the normal mass flux condition, the no-slip condition and stress balances. We also identify the heat flux balance condition which is modified to account for the flow, interface curvature and density difference between the bulk phases. The interface temperature satisfies a nonequilibrium version of the Clausius-Clapeyron relation which includes the effects of curvature, attachment kinetics and viscous dissipation. (C) 2001 Published by Elsevier Science B.V. C1 George Mason Univ, Dept Math Sci, Fairfax, VA 22030 USA. NIST, Math & Computat Sci Div, Gaithersburg, MD 20899 USA. Univ Southampton, Fac Math Studies, Southampton SO17 1BJ, Hants, England. RP George Mason Univ, Dept Math Sci, Fairfax, VA 22030 USA. EM danders1@gmu.edu RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 48 TC 42 Z9 43 U1 0 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 EI 1872-8022 J9 PHYSICA D JI Physica D PD MAY 1 PY 2001 VL 151 IS 2-4 BP 305 EP 331 DI 10.1016/S0167-2789(01)00229-9 PG 27 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 433TG UT WOS:000168775400011 ER PT J AU Schultz-Johanning, M Kling, R Schnabel, R Kock, H Li, Z Lundberg, H Johansson, S AF Schultz-Johanning, M Kling, R Schnabel, R Kock, H Li, Z Lundberg, H Johansson, S TI Lifetimes, branching fractions, and oscillator strengths of doubly ionized Tungsten SO PHYSICA SCRIPTA LA English DT Article ID LASER-INDUCED-FLUORESCENCE; RADIATIVE LIFETIMES; VACUUM-ULTRAVIOLET; HOLLOW-CATHODE; II LEVELS; DISCHARGE; ENERGIES; SPECTRUM; RATIOS; LEVEL AB A first small set of W III oscillator strengths has been obtained from combined lifetime and branching fraction measurements. The branching fractions in the wavelength region of 154-334 nm were measured with a Penning discharge and a Fourier transform spectrometer. Three levels have been calibrated on absolute scales with lifetimes measured with the time-resolved laser-induced fluorescence technique. The f-values derived have uncertainties of about 8% at best. A comparison with Cowan-code calculations is given since no other data are available in the literature. C1 Leibniz Univ Hannover, Abt Plasmaphys, Inst Atom & Mol Phys, D-30167 Hannover, Germany. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Lund Inst Technol, Dept Phys, S-22100 Lund, Sweden. Dept Phys, S-22100 Lund, Sweden. RP Schultz-Johanning, M (reprint author), Leibniz Univ Hannover, Abt Plasmaphys, Inst Atom & Mol Phys, D-30167 Hannover, Germany. EM michael.schultz@pmp.uni-hannover.de OI Li, Zhongshan/0000-0002-0447-2748 NR 25 TC 5 Z9 5 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. PD MAY PY 2001 VL 63 IS 5 BP 367 EP 371 DI 10.1238/Physica.Regular.063a00367 PG 5 WC Physics, Multidisciplinary SC Physics GA 432XZ UT WOS:000168722600004 ER PT J AU Indelicato, P Mohr, PJ AF Indelicato, P Mohr, PJ TI Coordinate-space approach to the bound-electron self-energy: Self-energy screening calculation SO PHYSICAL REVIEW A LA English DT Article ID STRONG COULOMB FIELD; LAMB-SHIFT CALCULATIONS; GROUND-STATE ENERGY; HELIUM-LIKE IONS; RADIATIVE-CORRECTIONS; VACUUM-POLARIZATION; ATOMIC-STRUCTURE; DIRAC-FOCK; POTENTIALS AB The self-energy screening correction is evaluated in a model in which the effect of the screening electron is represented as a first-order perturbation of the self-energy by an effective potential. The effective potential is the Coulomb potential of the spherically averaged charge density of the screening electron. We evaluate the energy shift due to a 1s(1/2),2s(1/2), 2P(1/2) or 2P(3/2) electron screening a 1s(1/2), 2S(1/2), 2p(1/2), or 2p(3/2) electron, for nuclear charge Z in the range 5 less than or equal toZ less than or equal to 92. A detailed comparison with other calculations is made. C1 Ecole Normale Super, Lab Kastler Brossel, CNRS, UMR C8552, F-75252 Paris 05, France. Univ Paris 06, F-75252 Paris, France. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Indelicato, P (reprint author), Ecole Normale Super, Lab Kastler Brossel, CNRS, UMR C8552, Case 74,4 Pl Jussieu, F-75252 Paris 05, France. RI Indelicato, Paul/D-7636-2011 OI Indelicato, Paul/0000-0003-4668-8958 NR 35 TC 22 Z9 22 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 2001 VL 63 IS 5 BP art. no. EP 052507 DI 10.1103/PhysRevA.63.052507 PG 22 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 430RJ UT WOS:000168589100050 ER PT J AU Bohn, JL AF Bohn, JL TI Inelastic collisions of ultracold polar molecules SO PHYSICAL REVIEW A LA English DT Article ID RELAXATION RATES; ATOMIC-HYDROGEN; SPIN-EXCHANGE; SCATTERING; TRAP AB The collisional stability of ultracold polar molecules in electrostatic traps is considered. Rate constants for collisions that drive molecules from weak-electric-field-seeking to strong-field-seeking states are estimated using a simple model that emphasizes long-range dipolar forces. The rate constants for collisional losses are found to vary substantially as a function of molecular parameters used in the model, such as dipole moment, mass, and the splitting of the molecular Lambda doublet. Varying these parameters over physically reasonable ranges yields rate constants as low as 10(-20) cm(3)/sec and as high as 10(-10) cm(3)/sec. Nevertheless. the loss rates rise dramatically in the presence of the externally applied trapping electric field. For this reason it is argued that electrostatic traps are likely to be less stable against collisional losses than their magnetic counterparts. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Bohn, JL (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 22 TC 62 Z9 63 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 2001 VL 63 IS 5 AR 052714 DI 10.1103/PhysRevA.63.052714 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 430RJ UT WOS:000168589100071 ER PT J AU Hwang, SR Li, WH Lee, KC Lynn, JW Luo, HM Ku, HC AF Hwang, SR Li, WH Lee, KC Lynn, JW Luo, HM Ku, HC TI Structural and magnetic properties of Pr1+xBa2-xCu3O7+y SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-DIFFRACTION; PR; PRBA2CU3O7; ORDER; SUPERCONDUCTIVITY; SUSCEPTIBILITY; CU AB The effects of the incorporation of Pr atoms onto the Pa sites on the structural and magnetic properties of Pr1 + xBa2 - xCu3O7 + y, with x = 0.22 and 0.48, were studied by using neutron diffraction and ac magnetic susceptibility measurements. Rietveld structural analysis shows that extra O atoms are pulled into the antichain sites, driving a structural change from an orthorhombic Pmmm to a tetragonal P4/mmm symmetry, when the chain and antichain sites become equally populated. Significant reductions in the ordering temperature of the Pr spins were found while the simple antiferromagnetic arrangement remained the same. These observations are consistent with the Pr-O distance increasing with increasing Pr doping. No changes in the structure or magnetic behavior were found for the CuO2 layers. C1 Natl Cent Univ, Dept Phys, Chungli 32054, Taiwan. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Natl Tsing Hua Univ, Dept Phys, Hsinchu 300, Taiwan. RP Hwang, SR (reprint author), Natl Cent Univ, Dept Phys, Chungli 32054, Taiwan. NR 23 TC 1 Z9 1 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 MAY 1 PY 2001 VL 63 IS 17 AR 172401 PG 4 WC Physics, Condensed Matter SC Physics GA 428XQ UT WOS:000168487300010 ER PT J AU Wakimoto, S Birgeneau, RJ Lee, YS Shirane, G AF Wakimoto, S Birgeneau, RJ Lee, YS Shirane, G TI Hole concentration dependence of the magnetic moment in superconducting and insulating La2-xSrxCuO4 SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-SCATTERING; DOPED LA2-XSR(X)CUO4; SPIN CORRELATIONS; PHASE-DIAGRAM; ORDER; STATE; ANTIFERROMAGNETISM; LA1.88SR0.12CUO4; LA2-XBAXCUO4; FLUCTUATIONS AB Recent neutron-scattering measurements on the La2-xSrxCuO4 system have revealed a drastic change of the incommensurate static-spin correlations from diagonal in the insulating region to parallel in the superconducting region. We report the eloping dependence of the ordered magnetic moment for the hole concentration region 0.03 less than or equal to x less than or equal to 0.12, focusing on the relationship between the static magnetism and the superconductivity. The elastic magnetic cross-section decreases monotonically with increasing x for 0.03 less than or equal to x less than or equal to 0.07. We find that the ordered magnetic moment mu varies from similar to 0.18 mu (B)/Cu(x = 0.03) to similar to 0.06 mu (B)/Cu(x = 0.07). No significant anomaly is observed at the: insulator-superconductor boundary (x similar to 0.055). The elastic magnetic cross-section is enhanced in the vicinity of x = 0.12 where resolution-limited width peaks are observed in neutron-scattering measurements and where the apparent magnetic and superconducting transitions coincide. C1 MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. NCNR, Natl Inst Stand & Technol, Bethesda, MD 20889 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Univ Toronto, Dept Phys, 60 St George St, Toronto, ON M5S 1A7, Canada. NR 29 TC 44 Z9 44 U1 1 U2 4 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 MAY 1 PY 2001 VL 63 IS 17 AR 172501 DI 10.1103/PhysRevB.63.172501 PG 4 WC Physics, Condensed Matter SC Physics GA 428XQ UT WOS:000168487300030 ER PT J AU Brome, CR Butterworth, JS Dzhosyuk, SN Mattoni, CEH McKinsey, DN Doyle, JM Huffman, PR Dewey, MS Wietfeldt, FE Golub, R Habicht, K Greene, GL Lamoreaux, SK Coakley, KJ AF Brome, CR Butterworth, JS Dzhosyuk, SN Mattoni, CEH McKinsey, DN Doyle, JM Huffman, PR Dewey, MS Wietfeldt, FE Golub, R Habicht, K Greene, GL Lamoreaux, SK Coakley, KJ TI Magnetic trapping of ultracold neutrons SO PHYSICAL REVIEW C LA English DT Article ID COLD NEUTRONS; LIQUID-HELIUM; SUPERFLUID-HELIUM; STORAGE RING; LIFETIME; HE-4; SCATTERING; LIGHT; DECAY; UCN AB Three-dimensional magnetic confinement of neutrons is reported. Neutrons are loaded into an Ioffe-type superconducting magnetic trap through inelastic scattering of cold neutrons with He-4. Scattered neutrons with sufficiently low energy and in the appropriate spin state are confined by the magnetic field until they decay. The electron resulting from neutron decay produces scintillations in the liquid helium bath that results in a pulse of extreme ultraviolet light. This light is frequency downconverted to the visible and detected. Results are presented in which 500+/-155 neutrons are magnetically trapped in each loading cycle, consistent with theoretical predictions. The lifetime of the observed signal, 660(-170)(+290) s, is consistent with the neutron beta-decay lifetime. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Harvard Univ, Cambridge, MA 02138 USA. Hahn Meitner Inst Kernforsch Berlin GmbH, D-14109 Berlin, Germany. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Brome, CR (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,MS 8461, Gaithersburg, MD 20899 USA. RI Habicht, Klaus/K-3636-2013; OI Habicht, Klaus/0000-0002-9915-7221; Huffman, Paul/0000-0002-2562-1378 NR 47 TC 20 Z9 20 U1 0 U2 6 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 MAY PY 2001 VL 63 IS 5 AR 055502 DI 10.1103/PhysRevC.63.055502 PG 15 WC Physics, Nuclear SC Physics GA 431PZ UT WOS:000168640900047 ER PT J AU Lobkovsky, AE Warren, JA AF Lobkovsky, AE Warren, JA TI Sharp interface limit of a phase-field model of crystal grains SO PHYSICAL REVIEW E LA English DT Article ID BOUNDARY; ROTATION; GROWTH; RECRYSTALLIZATION; KINETICS; SYSTEM AB We analyze a two-dimensional phase field model designed to describe the dynamics of crystalline grains. The phenomenological free energy is a functional of two order parameters. The first one reflects the orientational order, while the second reflects the predominantally local orientation of the crystal. We consider the gradient flow of this free energy. Solutions can be interpreted as ensembles of grains tin which the orientation is constant in space) separated by grain boundaries. We study the dynamics of the boundaries as well as the rotation of the grains. In the limit of an infinitely sharp interface, the normal velocity of the boundary is proportional to both its curvature and its energy. We obtain explicit formulas for the interfacial energy and mobility, and study their behavior in the limit of a small misorientation. We calculate the rate of rotation of a grain in the sharp interface limit, and find that it depends sensitively on the choice of the model. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Lobkovsky, AE (reprint author), Natl Inst Stand & Technol, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 26 TC 22 Z9 22 U1 1 U2 14 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD MAY PY 2001 VL 63 IS 5 AR 051605 DI 10.1103/PhysRevE.63.051605 PN 1 PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 432ZK UT WOS:000168730700037 PM 11414914 ER PT J AU Arp, U Fraser, GT Walker, ARH Lucatorto, TB Lehmann, KK Harkay, K Sereno, N Kim, KJ AF Arp, U Fraser, GT Walker, ARH Lucatorto, TB Lehmann, KK Harkay, K Sereno, N Kim, KJ TI Spontaneous coherent microwave emission and the sawtooth instability in a compact storage ring SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article ID SYNCHROTRON RADIATION; MILLIMETER WAVELENGTHS; BUNCH; SUBMILLIMETER AB Strong evidence for self-excited emission of coherent synchrotron radiation in the microwave spectral region was observed at the Synchrotron Ultraviolet Radiation Facility (SURF III) electron storage ring at the NIST. The microwave emission between 25 and 35 mm was dominated by intense bursts of radiation. The intensity enhancement during these bursts was on the order of 10 000 to 50 000 over the incoherent value. The shape, width, and period of the bursts depend strongly on the operational parameters of the storage ring. Coherent microwave emission was observed only when the beam was unstable, namely, during bunch-length relaxation oscillations. We report on the measurements of the microwave bursts, and correlate the data with signals from a beam monitor electrode and photodiode detector. The coherent enhancement of the radiation intensity is ascribed to spontaneous self-induced microbunching of the electrons within the bunch. C1 Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Arp, U (reprint author), Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. RI Arp, Uwe/C-2854-2009; Hight Walker, Angela/C-3373-2009 OI Hight Walker, Angela/0000-0003-1385-0672 NR 37 TC 29 Z9 29 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD MAY PY 2001 VL 4 IS 5 AR 054401 DI 10.1103/PhysRevSTAB.4.054401 PG 9 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 461MM UT WOS:000170368100004 ER PT J AU Jones, RM AF Jones, RM TI The dispersion relation for internal acoustic-gravity waves in a baroclinic fluid SO PHYSICS OF FLUIDS LA English DT Article ID FORMULATION; PROPAGATION; PHASES; SHEAR; FLOW AB The dispersion relation for internal waves in a fluid is generalized from the barotropic approximation to the baroclinic case to allow for the inclination of surfaces of constant density to surfaces of constant pressure. This generalization allows the barotropic approximation to be tested in a variety of situations. The dispersion relation applies to both acoustic waves and internal gravity waves propagating in either the ocean or the atmosphere. Imaginary terms in the dispersion relation proportional to the baroclinic vector indicate energy exchange between the wave and the mean flow, a result of buoyancy being a nonconservative force in a baroclinic fluid. A buoyancy calculation shows that the baroclinic generalization of the Brunt-Vaisala frequency N is given by N-2=del rho (theta).delp/rho (2), where rho is density, rho (theta) is potential density, and p is pressure. The baroclinicity in a weather front or cyclonic ring can sometimes have as large an effect as the Earth's rotation on the propagation of internal gravity waves. (C) 2001 American Institute of Physics. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Jones, RM (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. OI JONES, RICHARD MICHAEL/0000-0002-9493-7456 NR 30 TC 8 Z9 8 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD MAY PY 2001 VL 13 IS 5 BP 1274 EP 1280 DI 10.1063/1.1359419 PG 7 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 420ZU UT WOS:000168037200018 ER PT J AU Zank, GP Muller, HR Wood, BE AF Zank, GP Muller, HR Wood, BE TI The interaction of the solar wind and stellar winds with the partially ionized interstellar medium SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 42nd Annual Meeting of the Division of Plasma Physics Of the American-Physical-Society/10th International Congress on Plasma Physics CY OCT 23-27, 2000 CL QUEBEC CITY, CANADA SP Amer Phys Soc, Div Plasma Phys ID LY-ALPHA ABSORPTION; TERMINATION SHOCK; MAGNETIC-FIELD; HELIOSPHERE; HYDROGEN; HELIOPAUSE; SIMULATIONS; MODELS; CLOUD; IONIZATION AB Plasmas in the laboratory and interstellar and interplanetary space are frequently partially ionized. Thus, the solar wind and stellar winds often interact with an interplanetary medium that is an admixture of protons, electrons, other charged ions, and neutral atoms. For example, the very local interstellar medium surrounding our heliosphere may be less than 50% ionized, with the dominant constituent being neutral hydrogen (H). As a result, the composition of the solar wind in the outer heliosphere beyond some 10-15 AU is dominated by neutral interstellar H. Our understanding of the complex physics describing the interaction of the solar wind with the partially ionized local interstellar medium (ISM) has advanced significantly in the last 5 years with the development of very sophisticated models which treat the coupling of neutral atoms and plasma self-consistently. A number of major predictions have emerged from these models, such as the existence of a large wall of heated neutral hydrogen upstream of the heliosphere. Remarkably, in the ensuing years, this prediction has been confirmed by high-resolution Hubble Space Telescope Lyman-alpha spectroscopic data. Subsequent models now consider the interaction of various stellar winds with the ISM, and Hubble observations provide supporting data. An introductory review of the basic physics, and associated observations, of the interaction of the solar wind and stellar winds with the interstellar medium is presented for this exciting and rapidly developing field. (C) 2001 American Institute of Physics. C1 Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Zank, GP (reprint author), Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. NR 50 TC 13 Z9 13 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 2001 VL 8 IS 5 BP 2385 EP 2393 DI 10.1063/1.1345502 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 423QP UT WOS:000168188500078 ER PT J AU Phelps, AV AF Phelps, AV TI Abnormal glow discharges in Ar: experiments and models SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT XVth Europhysics Conference on Atomic and Molecular Physics of Ionized Gases CY AUG 26-30, 2000 CL LILLAFURED, HUNGARY SP European Phys Soc ID SCATTERING CROSS-SECTIONS; ARGON METASTABLE ATOMS; MONTE-CARLO SIMULATION; CATHODE SHEATH REGION; LOW-PRESSURE; GAS TEMPERATURE; NEGATIVE-GLOW; 2-DIMENSIONAL MODEL; PARTICLE SIMULATION; ENERGY-DISTRIBUTION AB We review measured and calculated voltages and cathode-fall thicknesses against current and electrode separation for parallel-plane Ar glow discharges in the above-normal, or abnormal, current range. We consider dc and pulsed discharges, but not radio-frequency discharges. Reasons for the very high degree of variability among experiments and models are reviewed and suggestions are made for improving the reliability of both. Variations of a factor of two in experimental cathode-fall voltages at a fixed normalized current density are attributed to differences in the cathode emission properties, varying electrode separation, and effects of discharge tube walls. We explore a wide range of normalized current densities, models of the ionization coefficient against E / n, and the effective electron yields per positive ion reaching the cathode using simple scaling laws. Ionization source terms for local-field and non-local-field models are compared and used as the basis for a simplified non-local model. We discuss the present author's recommendation that, because of current large uncertainties in the electron yield per ion for practical cathodes, the yield used in cathode-fall models should be treated as an unknown. Recent models successfully predict the behaviour of transient abnormal discharges on the microsecond time scale. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 137 TC 43 Z9 43 U1 1 U2 14 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0963-0252 EI 1361-6595 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD MAY PY 2001 VL 10 IS 2 BP 329 EP 343 DI 10.1088/0963-0252/10/2/323 PG 15 WC Physics, Fluids & Plasmas SC Physics GA 441YY UT WOS:000169258200024 ER PT J AU Chou, KF Han, CC Lee, S AF Chou, KF Han, CC Lee, S TI Buffer transport in hydroxyethyl methacrylate copolymer irradiated by gamma-rays SO POLYMER LA English DT Article DE buffer; gamma-ray; hydroxyethyl methacrylate ID PHASE-TRANSITION; 2-HYDROXYETHYL METHACRYLATE; MECHANICAL DEFORMATION; METHANOL TRANSPORT; WATER TRANSPORT; IONIC GELS; PH; SALT; PMMA AB The transport of buffer solutions (pH 4.1-7.2) in hydroxyethyl methacrylate copolymer (HEMA) is investigated. The diffusion coefficient of Case I transport, the velocity of Case II transport and the activation energy of the transport process in non-irradiated HEMA are determined. The buffer transport in HEMA copolymers irradiated by gamma -rays in vacuum and in air is also studied. After irradiation, the data of mass gain at the short times and long times are designated as stages 1 and 2, respectively. The first stage is followed in Case I transport when the specimen is irradiated in vacuum and the anomalous transport when irradiated in air. The second stage, regardless of the irradiation atmosphere is followed in Case II transport. The equilibrium swelling ratio of irradiated specimens increases significantly when the pH value is greater than 5. A volume transition is observed at high gamma -ray doses. The effect of gamma -ray irradiation on the functional groups in the polymer is investigated using the infrared spectra. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Natl Tsing Hua Univ, Dept Mat Sci & Engn, Hsinchu 30043, Taiwan. NIST, Div Polymer, Gaithersburg, MD 20899 USA. RP Lee, S (reprint author), Natl Tsing Hua Univ, Dept Mat Sci & Engn, 101,Sec 2 Kuang Fu Rd, Hsinchu 30043, Taiwan. NR 23 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD MAY PY 2001 VL 42 IS 11 BP 4989 EP 4996 DI 10.1016/S0032-3861(00)00895-8 PG 8 WC Polymer Science SC Polymer Science GA 409KD UT WOS:000167382100025 ER PT J AU Shaffner, TJ AF Shaffner, TJ TI Semiconductor characterization and analytical technology (vol 88, pg 1416, 2000) SO PROCEEDINGS OF THE IEEE LA English DT Correction C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Shaffner, TJ (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD MAY PY 2001 VL 89 IS 5 SI SI BP 789 EP 789 DI 10.1109/JPROC.2001.929654 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA 445GZ UT WOS:000169450900010 ER PT J AU Egelhoff, WF Chen, PJ Powell, CJ McMichael, RD Stiles, MD AF Egelhoff, WF Chen, PJ Powell, CJ McMichael, RD Stiles, MD TI Surface and interface effects in the growth of giant magnetoresistance spin valves for ultrahigh-density data-storage applications SO PROGRESS IN SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 20th International Seminar on Surface Physics CY JUN 19-24, 2000 CL KUDOWA ZDROJ, POLAND SP Univ Wroclaw, Inst Exptl Phys, Polish State Comm Sci Res, German Phys Soc, Phys Electr GmbH, Shimadzu Polska - Analityka DE hard-disk drive; giant magnetoresistance; read-heads ID BY-LAYER GROWTH; HOMOEPITAXIAL GROWTH; MULTILAYERS; CU(100); SUPERLATTICES; EPITAXY; CU(110); AG(111); OXYGEN; ENERGY AB The current generation of hard-disk drives use giant magneto resistance (GMR) spin valves as the read-head because the GMR effect is currently the most sensitive way to detect magnetic fields at submicron length scales and data rates of approximate to 10(8) Hz. At present, hard-disk capacities are doubling approximately every year. To maintain this growth rate, GMR values will have to double approximately every two years. To achieve such GMR values, major progress will have to be made in controlling surface and interface effects in the growth of GMR spin valves. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Egelhoff, WF (reprint author), Natl Inst Stand & Technol, Mail Stop 8558, Gaithersburg, MD 20899 USA. RI McMichael, Robert/J-8688-2012; Stiles, Mark/K-2426-2012; OI Stiles, Mark/0000-0001-8238-4156; McMichael, Robert/0000-0002-1372-664X NR 32 TC 23 Z9 23 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6816 J9 PROG SURF SCI JI Prog. Surf. Sci. PD MAY-AUG PY 2001 VL 67 IS 1-8 BP 355 EP 364 DI 10.1016/S0079-6816(01)00036-3 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 460QC UT WOS:000170319200028 ER PT J AU Rumble, J Lee, AY Blakeslee, D Young, S AF Rumble, J Lee, AY Blakeslee, D Young, S TI Reliable solubility data in the age of computerized chemistry. Why, how, and when? SO PURE AND APPLIED CHEMISTRY LA English DT Article; Proceedings Paper CT 9th International Symposium on Solubility Phenomena (9th ISSP) CY JUL 25-28, 2000 CL HAMMAMET, TUNISIA SP IUPAC, Analyt Div, Tunisian Chem Soc AB Since 1979, the International Union of Pure and Applied Chemistry (IUPAC) Commission V.8 on Solubility Data has published over 70 compilations of evaluated data on the solubility of gases in liquids, liquids in liquids, and solids in liquids. These volumes represent one of the largest collections of chemical property data ever produced and are the result of work of scientists throughout the world. In 1998, IUPAC signed an agreement with the National Institute of Standards and Technology (NIST) to continue the series by replacing the monographs by articles in the Journal of Physical and Chemical Reference Data. Five data compilations have already been published in the Journal, and many more are under way. Recently, IUPAC and NIST have concluded another agreement about computerizing all previously published IUPAC solubility data. In this paper, we describe in detail the computerization of IUPAC solubility data, with some emphasis on harmonizing data published over a long time period. We describe the anticipated query paths that will be supported. We also discuss some of the driving forces for making these and other data resources available over the World Wide Web. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Rumble, J (reprint author), Natl Inst Stand & Technol, 100 Bureau Dr MS 2310, Gaithersburg, MD 20899 USA. NR 3 TC 3 Z9 3 U1 0 U2 3 PU INT UNION PURE APPLIED CHEMISTRY PI RES TRIANGLE PK PA 104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USA SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD MAY PY 2001 VL 73 IS 5 BP 825 EP 829 DI 10.1351/pac200173050825 PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA 454DZ UT WOS:000169958300007 ER PT J AU Shaw, PS Larason, TC Gupta, R Brown, SW Vest, RE Lykke, KR AF Shaw, PS Larason, TC Gupta, R Brown, SW Vest, RE Lykke, KR TI The new ultraviolet spectral responsivity scale based on cryogenic radiometry at Synchrotron Ultraviolet Radiation Facility III SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID NORMAL-INCIDENCE MONOCHROMATOR; SURF-II; DETECTOR CALIBRATION; NATIONAL-INSTITUTE; STANDARDS; NIST; NM AB The recently completed upgrade of the Synchrotron Ultraviolet Radiation Facility (SURF III) at the National Institute of Standards and Technology (NIST) has improved the accuracy of radiometric measurements over a broad spectral range from the infrared to the soft x ray. The beamline 4 at SURF III is a cryogenic-radiometer based radiometric facility for the ultraviolet (UV) spectral range. The upgrade of SURF III has allowed us to use beamline 4 to improve the detector spectral power responsivity scales in the wavelength range from 125 to 320 nm. The achieved combined relative standard uncertainty is better than 0.5% over most of this spectral range. This is a significant improvement over the more than 6% relative standard uncertainty in this spectral range of the current scales maintained at the Spectral Comparator Facility (SCF) in the Optical Technology Division and the Far UV Calibration Facility in the Electron and Optical Physics Division. The new UV scale of beamline 4 was subsequently intercompared and transferred to the SCF and to the Far UV Calibration Facility to improve their UV scales and ensure consistency within NIST. The new scale established at beamline 4 improves NIST's calibration capabilities for environmental monitoring, astrophysics, and the UV industry. The new scale also includes wavelengths such as 193 and 157 nm excimer laser wavelengths, which are of particular interest to the semiconductor photolithography industry. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Shaw, PS (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 22 TC 25 Z9 28 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAY PY 2001 VL 72 IS 5 BP 2242 EP 2247 DI 10.1063/1.1361081 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 424VH UT WOS:000168254300002 ER PT J AU Klein, EJ Ramirez, WF Hall, JL AF Klein, EJ Ramirez, WF Hall, JL TI A common-path heterodyne interferometer for surface profiling in microelectronic fabrication SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID END-POINT DETECTION; FOCUSED ION-BEAM; ENDPOINT DETECTION; MASS-SPECTROMETRY; REFLECTOMETRY; REFLECTANCE; FILMS; LASER AB We describe the design of a common-path heterodyne laser interferometer for the surface profiling of micron-sized photopatterned features during the microelectronic fabrication process. The common-path design of the interferometer's reference and measurement arms effectively removes any path length difference in the measurement which can be attributed to the movement of the target surface. It is shown that repeated surface profiling during the ion milling process allows the difference in etch rates between the photoresist layer and the exposed portions of the underlying substrate layer to be monitored online. A prototype apparatus has been assembled and results demonstrating the usefulness of the device are reported. The surface profiles of both a photopatterned nickel-iron trench and an unmasked aluminum trench are measured and compared to those obtained using a stylus-based scanning profiler and an atomic force microscope. (C) 2001 American Institute of Physics. C1 Univ Colorado, Dept Chem Engn, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Ramirez, WF (reprint author), Univ Colorado, Dept Chem Engn, Campus Box 424, Boulder, CO 80309 USA. NR 21 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAY PY 2001 VL 72 IS 5 BP 2455 EP 2466 DI 10.1063/1.1367353 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 424VH UT WOS:000168254300037 ER PT J AU Manning, JA Kidd, A AF Manning, JA Kidd, A TI NOAA satellite active archive & derived environmental products SO SEA TECHNOLOGY LA English DT Article C1 Sci & Technol Corp, Hampton, VA 23666 USA. NOAA, NESDIS Satellite Act Arch, Suitland, MD USA. RP Manning, JA (reprint author), Sci & Technol Corp, Hampton, VA 23666 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 MAY PY 2001 VL 42 IS 5 BP 51 EP 53 PG 3 WC Engineering, Ocean SC Engineering GA 436BC UT WOS:000168915800008 ER PT J AU Withee, GW Smith, DB Masters, RO AF Withee, GW Smith, DB Masters, RO TI The prospects for enhanced international polar-orbiting satellite cooperation SO SPACE POLICY LA English DT Article AB With robust polar satellite missions demonstrated and/or operational in the USA, Europe, Japan, China, Russia, India, and Brazil, and with other nations also likely to develop such capability, this paper examines the prospects for as well as the potential challenges to closer and perhaps more formal international polar satellite cooperation. In suggesting that now is the time to explore the development of a coordinated polar observing system, the present paper identifies potential contributors, assesses the relevance of existing space-based Earth observation international coordination mechanisms, and considers three potential models for a future system. Published by Elsevier Science Ltd. C1 NOAA, Natl Enivironm Satellite Data & Informat Serv, Silver Spring, MD 20910 USA. RP Smith, DB (reprint author), NOAA, Natl Enivironm Satellite Data & Informat Serv, 1335 East West Highway,Room 7311, Silver Spring, MD 20910 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0265-9646 J9 SPACE POLICY JI Space Policy PD MAY PY 2001 VL 17 IS 2 BP 121 EP 126 DI 10.1016/S0265-9646(01)00008-X PG 6 WC International Relations; Social Sciences, Interdisciplinary SC International Relations; Social Sciences - Other Topics GA 435GZ UT WOS:000168870200009 ER PT J AU Collis, K Roby, DD Craig, DP Ryan, BA Ledgerwood, RD AF Collis, K Roby, DD Craig, DP Ryan, BA Ledgerwood, RD TI Colonial waterbird predation on juvenile salmonids tagged with passive integrated transponders in the Columbia river estuary: Vulnerability of different salmonid species, stocks, and rearing types SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID STEELHEAD TROUT; ONCORHYNCHUS-MYKISS; HATCHERY; WILD; EXPERIENCE; BEHAVIOR; SURVIVAL; STRESS; GROWTH; SALAR AB Passive integrated transponder (PIT) tags implanted in Columbia River basin juvenile salmonids Oncorhyncus spp. were recovered from breeding. colonies of Caspian terns Sterna caspia and double-crested cormorants Phalacrocorax auritus on Rice Island, a dredge spoil island in the Columbia River estuary. Tags were recovered to assess the relative vulnerability of different salmonid species, stocks, and rearing types to avian predators. We detected 50,221 PIT tags at the two bird colonies, mostly from juvenile chinook salmon O. tshawytscha and steelhead O. mykiss raised in hatcheries; 72% of the total tags were from the tern colony and 28% from the cormorant colony. Tagged steelhead smolts were more vulnerable to predation by both bird species than were yearling chinook salmon. More than 15% of PIT tags from steelhead smolts that were available in the estuary in 1998 were detected at the bird colonies compared with 2% of PIT tags from yearling chinook salmon. The greater vulnerability of steelhead may reflect size-dependent selection by avian predators. Salmonids listed under the Endangered Species Act and unlisted salmonids were equally vulnerable to predation by both terns and cormorants. Hatchery-raised yearling chinook salmon were more vulnerable than their wild counterparts to predation by terns, a surface-feeding species; however, hatchery-raised and wild yearling chinook salmon were equally vulnerable to predation by cormorants, a diving species. These results suggest that hatchery-raised yearling chinook salmon, and hatchery-raised steelhead in some years, are more vulnerable to tern predation than wild fish because they have a greater tendency to reside near the water surface where terns forage. C1 Columbia River Intertribal Fish Commiss, Portland, OR 97232 USA. Oregon State Univ, Dept Fisheries & Wildlife, US Geol Survey, Oregon Cooperat Fish & Wildlife Res Unit, Corvallis, OR 97331 USA. Natl Marine Fisheries Serv, Point Adams Biol Field Stn, Hammond, OR 97121 USA. RP Collis, K (reprint author), Real Time Res, 201 Yellowtail Hawk Ave, Bend, OR 97701 USA. NR 61 TC 79 Z9 80 U1 4 U2 20 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAY PY 2001 VL 130 IS 3 BP 385 EP 396 DI 10.1577/1548-8659(2001)130<0385:CWPOJS>2.0.CO;2 PG 12 WC Fisheries SC Fisheries GA 439EJ UT WOS:000169097600005 ER PT J AU Logerwell, EA AF Logerwell, EA TI Metabolic rate of California Pacific sardine estimated from energy losses during starvation SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID PATTERNS; SAGAX; ENERGETICS; RESPONSES; JUVENILES; FISHES; GROWTH AB The nonfeeding swimming metabolism of adult Pacific sardine Sardinops sagax was estimated from starvation experiments during which energy losses in fasting fish were measured. Because sardine were kept in groups and handling during the experiment was minimal, stress was probably less than in previous respirometry experiments with sardine. The experiment was conducted at 17.5 degreesC, with sardine swimming spontaneously at 0.5 body length/s. The resulting estimate of metabolism was 0.042 +/- 0.124 kJ.g wet mass(-1).d(-1), which compares favorable with estimates of metabolism in other clupeoids. It is also similar to the metabolism of sardine in a different system, the Benguela Current off South Africa, which as derived from respirometry. C1 SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Logerwell, EA (reprint author), Alaska Fisheries Sci Ctr, F-AKC3,POB 15700, Seattle, WA 98115 USA. NR 31 TC 3 Z9 3 U1 2 U2 6 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAY PY 2001 VL 130 IS 3 BP 526 EP 530 DI 10.1577/1548-8659(2001)130<0526:MROCPS>2.0.CO;2 PG 5 WC Fisheries SC Fisheries GA 439EJ UT WOS:000169097600020 ER PT J AU McGuiggan, PM Zhang, J Hsu, SM AF McGuiggan, PM Zhang, J Hsu, SM TI Comparison of friction measurements using the atomic force microscope and the surface forces apparatus: the issue of scale SO TRIBOLOGY LETTERS LA English DT Article DE friction; surface forces apparatus; atomic force microscope; friction of thin films; tribology; scale ID SILICON SURFACES; MOLECULAR FILMS; MONOLAYERS; SHEAR; TRANSITIONS; DIAMOND; LIQUID; MICA AB Results are presented of lateral force measurements using the atomic force microscope (AFM) and the surface forces apparatus (SFA). Two different probes are used in the AFM measurements; a sharp silicon nitride tip (radius R approximate to 20 nm) and a glass ball (R approximate to 15 mum). The lateral force is measured between the (silicon nitride or glass) probe and a mica surface which has been coated by a thin lubricant film. Tn the SFA, a thin lubricant film separates two molecularly smooth mica surfaces (R approximate to 1 cm) which are slid relative to each other. Perfluoropolyether (PFPE) and polydimethylsiloxane (PDMS) were used as the lubricant films. In the SFA where the contact diameter is largest, the PFPE film shows much lower friction than PDMS. As the size of the probe decreases, the difference in the measured friction decreases. For sharp AFM tips, no clear distinction between the tribological properties of the films can be made. Hence, the measured coefficient of friction varies according to the length scare probed, at least for small dimensions. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Data Storage Inst, Singapore, Singapore. RP McGuiggan, PM (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RI McGuiggan, Patricia/A-3379-2010 NR 32 TC 34 Z9 34 U1 1 U2 22 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PD MAY PY 2001 VL 10 IS 4 BP 217 EP 223 DI 10.1023/A:1016692704748 PG 7 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 439MQ UT WOS:000169121000004 ER PT J AU Michaud, JD Hirschboeck, KK Winchell, M AF Michaud, JD Hirschboeck, KK Winchell, M TI Regional variations in small-basin floods in the United States SO WATER RESOURCES RESEARCH LA English DT Article ID FLASH FLOODS; EVENTS AB This paper presents a reconnaissance study of regional flood patterns in the United States, focusing on peak discharges at several recurrence intervals and characteristics of flood-causing rainfall. Because of an interest in flash floods, attention was restricted to watersheds between 10 and 200 km(2) in area. Data were obtained from 130 stream gaging stations with a consistent 30-year period of record and from reports documenting 90 exceptional floods occurring mostly on ungaged watersheds. Peak discharges vary considerably within local regions. Roughly 60% of the local variability can be explained by watershed characteristics, but watershed area is not a reliable predictor of peak discharge within the narrow range of watershed sizes examined. On a continental scale the spatial patterns of the median and 25-year floods are similar. In both cases a concentration of large floods is found in the southeastern Great Plains and parts of the southeast. In the west, north, and northeast, floods tend to be small, but large floods still occur in scattered locations. The pattern and seasonality of the exceptional floods, which are presumed to have relatively long recurrence intervals, are different from the pattern of median and 25-year floods. The largest of the exceptional floods are concentrated in the central and southern Great Plains during May and June. They occur farther west (and several months later) than the largest median floods. Exceptional floods occurring in the semiarid west were caused by as little as 5-10 cm of rain in 30-60 min, whereas in humid areas most of the exceptional floods resulted from 13-32 cm of rain in 1-12 hours. C1 Univ Hawaii, Dept Geol, Hilo, HI 96720 USA. Univ Arizona, Tree Ring Res Lab, Tucson, AZ 85721 USA. Natl Weather Serv, NE River Forecast Ctr, Taunton, MA 02780 USA. RP Michaud, JD (reprint author), Univ Hawaii, Dept Geol, 200 W Kawili St, Hilo, HI 96720 USA. NR 24 TC 17 Z9 17 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAY PY 2001 VL 37 IS 5 BP 1405 EP 1416 DI 10.1029/2000WR900283 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 425AP UT WOS:000168266400024 ER PT J AU Kroesen, BJ Pettus, B Luberto, C Busman, M Sietsma, H de Leij, L Hannun, YA AF Kroesen, BJ Pettus, B Luberto, C Busman, M Sietsma, H de Leij, L Hannun, YA TI Induction of apoptosis through B-cell receptor cross-linking occurs via de novo generated C16-ceramide and involves mitochondria SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID TUMOR-NECROSIS-FACTOR; CERAMIDE-INDUCED APOPTOSIS; MEDIATED APOPTOSIS; ANTIGEN RECEPTOR; WEHI-231 CELLS; CYTOCHROME-C; T-CELLS; ACTIVATION; INVOLVEMENT; SPHINGOMYELIN AB B-cells, triggered via their surface E-cell receptor (BcR), start an apoptotic program known as activation-induced cell death (AICD), and it is widely believed that this phenomenon plays a role in the restriction and focusing of the immune response. Although both ceramide and caspases have been proposed to be involved in AICD, the contribution of either and the exact molecular events through which AICD commences are still unknown. Here we show that in Ramos B-cells, BcR-triggered cell death is associated with an early rise of C16 ceramide that derives from activation of the de novo pathway, as demonstrated using a specific inhibitor of ceramide synthase, fumonisin B1 (FB1), and using pulse labeling with the metabolic sphingolipid precursor, palmitate, There was no evidence for activation of sphingomyelinases or hydrolysis of sphingomyelin. Importantly, FB1 inhibited several specific apoptotic hallmarks such as poly(A)DP-ribose polymerase cleavage and DNA fragmentation. Electron microscopy revealed morphological evidence of mitochondrial damage, suggesting the involvement of mitochondria in BcR-triggered apoptosis, and this was inhibited by FB1, Moreover; a loss of mitochondrial membrane potential was observed in Ramos cells after BcR cross-linking, which was inhibited by the addition of FB1. Interestingly, benzyloxycarbonyl-Val-Ala-DL-Asp, a broad spectrum caspase inhibitor did not inhibit BcR-induced mitochondrial membrane permeability transition but did block DNA fragmentation, These results suggest a crucial role for de novo generated C16 ceramide in the execution of AICD, and, they further suggest an ordered and more specific sequence of biochemical events in which de novo generated C16 ceramide is involved in mitochondrial damage resulting in a downstream activation of caspases and apoptosis. C1 Med Univ S Carolina, Dept Biochem & Mol Biol, Charleston, SC 29425 USA. Univ Groningen Hosp, Dept Pathol & Lab Med, NL-9713 G2 Groningen, Netherlands. Univ Groningen Hosp, Dept Pediat Oncol & Hematol, NL-9713 G2 Groningen, Netherlands. US Dept Commerce, Natl Ocean Serv, Charleston, SC 29412 USA. RP Hannun, YA (reprint author), Med Univ S Carolina, Dept Biochem & Mol Biol, 173 Ashley Ave, Charleston, SC 29425 USA. FU NIGMS NIH HHS [GM08716, GM43825] NR 50 TC 122 Z9 126 U1 0 U2 6 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD APR 27 PY 2001 VL 276 IS 17 BP 13606 EP 13614 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 426PB UT WOS:000168356600016 PM 11278517 ER PT J AU Seidel, DJ Ross, RJ Angell, JK Reid, GC AF Seidel, DJ Ross, RJ Angell, JK Reid, GC TI Climatological characteristics of the tropical tropopause as revealed by radiosondes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC WATER-VAPOR; FOUNTAIN HYPOTHESIS; TEMPERATURE TRENDS; GLOBAL TROPOPAUSE; ANNUAL CYCLE; HEIGHT; REEXAMINATION; SENSITIVITY; REANALYSES; HUMIDITY AB A temporally and spatially comprehensive depiction of the tropical tropopause is presented, based on radiosonde data from 83 stations. Climatological statistics for 1961-1990 are computed for three levels: the conventional lapse-rate tropopause (LRT), the cold-point tropopause (CPT), and the 100 hPa level. Mean values and seasonal and interannual variations of temperature, pressure, height, potential temperature, and water vapor saturation mixing ratio at these levels are compared. The tropopause is higher, colder, and at lower pressure in the Northern Hemisphere (NH) than in the Southern Hemisphere (SH) in NH winter. This pattern reverses in NH summer, except that the tropopause remains colder in the NH than in the SH. The climatological locations of minimum tropopause temperature differ from those of maximum height and minimum pressure: In NH winter the tropopause is coldest over the western tropical Pacific warm pool region, but it is highest and at lowest pressure over the western Atlantic. Correlations of interannual anomalies in zonal-mean characteristics reveal that the height of the tropopause reflects the temperature of the underlying troposphere. Tropopause. temperature, on the other hand, shows little association with tropospheric characteristics but is significantly correlated with the temperature and pressure of the lower stratosphere. The 100 hPa level is a poor surrogate for the tropical tropopause. Changes in radiosonde instrumentation limit the potential for detecting tropopause trends. However, the following (nonmonotonic) trends in the tropopause in the deep tropics during 1978-1997 seem robust: an increase in height of about 20 m decade(-1), a decrease in pressure of about 0.5 hPa decade(-1), a cooling of about 0.5 K decade(-1), little change in potential temperature, and a decrease in saturation volume mixing ratio of about 0.3 ppmv decade(-1). C1 NOAA, Air Resources Lab, R ARL, Silver Spring, MD 20910 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Seidel, DJ (reprint author), NOAA, Air Resources Lab, R ARL, 1315 WE Highway, Silver Spring, MD 20910 USA. NR 51 TC 185 Z9 199 U1 1 U2 25 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 27 PY 2001 VL 106 IS D8 BP 7857 EP 7878 DI 10.1029/2000JD900837 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 427ZW UT WOS:000168437500004 ER PT J AU Keckhut, P Wild, JD Gelman, M Miller, AJ Hauchecorne, A AF Keckhut, P Wild, JD Gelman, M Miller, AJ Hauchecorne, A TI Investigations on long-term temperature changes in the upper stratosphere using lidar data and NCEP analyses SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MIDDLE ATMOSPHERE; RADIOSONDE TEMPERATURE; RAYLEIGH LIDAR; CLIMATE-CHANGE; TRENDS; TIDES; INHOMOGENEITIES; VARIABILITY; SOUNDER AB OHP lidar data and National Centers for Environmental Prediction (NCEP) stratospheric temperature analyses provide long and continuous databases for the middle and upper stratosphere that are highly valuable for long-term studies. However, each data set has limitations. Comparisons between lidar data from 1979 to 1993 and NCEP data interpolated from the global analyses to the lidar location reveal significant mean temperature differences. Insight into the origin of the differences offers an opportunity to improve the overall quality of temperature monitoring in the stratosphere. Some of the differences can be explained by instrumental effects in the lidar system. In the stratosphere most of the limitations in lidar temperatures appear below 35-40 km, due to events of lidar misalignment (as large as 10 K) or to the effects on lidar data of volcanic aerosols (as large as 15 K), Changing biases between lidar and NCEP temperatures above 5 hPa coincide with replacement of satellites used in the NCEP analyses. However, some bias differences in upper stratospheric temperatures remain even after NCEP adjustments are made, based on rocketsonde comparisons. While these biases have been already suspected, they had never been explained. Here we suggest that the remaining bias (2-4 K) is caused by tidal influences, heretofore not accounted for by the NCEP adjustment procedure. Lidar profiles have been filtered in their lower part for misalignment and aerosol contamination. Long-term changes have been compared, and a factor of 2 in trend differences have been reported. No significant trends (at 95% confidence) have been detected except with lidar around the stratopause and with NCEP analyses at 5 and 10 hPa, According to instrumental limitations of both data sets the temperature trend may vary from 1 to 3 K with altitude (10-0.4 hPa). Because only satellite data can provide global trend estimates and because lidar data have been chosen for ground-based stratospheric monitoring programs, we suggest some plans to overcome these difficulties for past and future measurements. This should allow a more confident use for future trend estimates from both data sets. C1 IPSL, Serv Aeron, F-91371 Verrieres Buisson, France. Res & Data Syst Corp, Greenbelt, MD 20770 USA. NOAA, NCEP, Climate Predict Ctr, Washington, DC 20203 USA. RP Keckhut, P (reprint author), IPSL, Serv Aeron, BP3, F-91371 Verrieres Buisson, France. RI Hauchecorne, Alain/A-8489-2013; OI Hauchecorne, Alain/0000-0001-9888-6994 NR 43 TC 34 Z9 34 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 27 PY 2001 VL 106 IS D8 BP 7937 EP 7944 DI 10.1029/2000JD900845 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 427ZW UT WOS:000168437500009 ER PT J AU Stroud, CA Roberts, JM Goldan, PD Kuster, WC Murphy, PC Williams, EJ Hereid, D Parrish, D Sueper, D Trainer, M Fehsenfeld, FC Apel, EC Riemer, D Wert, B Henry, B Fried, A Martinez-Harder, M Harder, H Brune, WH Li, G Xie, H Young, VL AF Stroud, CA Roberts, JM Goldan, PD Kuster, WC Murphy, PC Williams, EJ Hereid, D Parrish, D Sueper, D Trainer, M Fehsenfeld, FC Apel, EC Riemer, D Wert, B Henry, B Fried, A Martinez-Harder, M Harder, H Brune, WH Li, G Xie, H Young, VL TI Isoprene and its oxidation products, methacrolein and methylvinyl ketone, at an urban forested site during the 1999 Southern Oxidants Study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NOCTURNAL BOUNDARY-LAYER; BIOGENIC HYDROCARBONS; VINYL KETONE; UNITED-STATES; DECIDUOUS FOREST; OZONE PRODUCTION; REGIONAL OZONE; TROPOSPHERE; ATMOSPHERE; EMISSIONS AB Isoprene (ISOP) and its oxidation products, methacrolein (MACR) and methyl vinyl ketone (MVK), were measured at an urban forested site in Nashville, Tennessee, as part of the 1999 Southern Oxidants Study (SOS). Hourly observations were performed at Cornelia Fort Airpark for a 4 week period between June 13 and July 14. At the midday photochemical peak (1200 local standard time, LST), average mixing ratios of isoprene, MACR, and MVK were 410 parts per trillion by volume (pptv), 240 pptv, and 430 pptv, respectively. Median isoprene, MACR, and MVK mixing ratios were 400 pptv, 200 pptv, and 360 pptv, respectively, at 1200 LST. An emissions inventory calculation for Davidson County, encompassing Nashville, suggests that MACR and MVK were produced predominately from isoprene oxidation rather than direct combustion emissions. The observations are compared with results from two chemical models: a simple sequential reaction scheme and a one-dimensional (1-D) numerical box model. The daytime ratios of MVK/ISOP and MACR/ISOP varied in a systematic manner and can be reproduced by the analytical solution of the sequential reaction scheme. Air masses with more photochemically aged isoprene were observed during SOS 1999 at Cornelia Fort (0.3-1.6 hours) compared to the SOS 1990 canopy study at Kinterbish (0.1-0.6 hours). This is consistent with the proximity of the tower inlets to the forest canopies during both campaigns. Isoprene had a chemical lifetime of 20 min at the average observed midday HO mixing ratio of 8 x 10(6) molecules/cm(3). As a result, significant conversion of isoprene to its oxidation products was observed on the timescale of transport from the dense forest canopies surrounding Nashville. The systematic diurnal behavior in the MVK/MACR ratio can also be simulated with a 1-D photochemical box model. General agreement between the observations of MACR and MVK during SOS 1999 with the two chemical models suggests we have a comprehensive understanding of the first few stages of isoprene oxidation in this urban forested environment. C1 Natl Ctr Atmospher Res, Atmospher Chem Div, Boulder, CO 80304 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. NOAA, Aeron Lab, Boulder, CO 80305 USA. Ohio Univ, Dept Chem Engn, Athens, OH 45701 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Stroud, CA (reprint author), York Univ, EATS Dept, N York, ON M3J 1P3, Canada. RI Roberts, James/A-1082-2009; Williams, Eric/F-1184-2010; Kuster, William/E-7421-2010; Parrish, David/E-8957-2010; Trainer, Michael/H-5168-2013; Fehsenfeld, Frederick/I-4876-2013; Harder, Hartwig/L-2511-2014 OI Roberts, James/0000-0002-8485-8172; Kuster, William/0000-0002-8788-8588; Parrish, David/0000-0001-6312-2724; Harder, Hartwig/0000-0002-6868-714X NR 31 TC 55 Z9 57 U1 2 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 27 PY 2001 VL 106 IS D8 BP 8035 EP 8046 DI 10.1029/2000JD900628 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 427ZW UT WOS:000168437500018 ER PT J AU Kates, RW Clark, WC Corell, R Hall, JM Jaeger, CC Lowe, I McCarthy, JJ Schellnhuber, HJ Bolin, B Dickson, NM Faucheux, S Gallopin, GC Grubler, A Huntley, B Jager, J Jodha, NS Kasperson, RE Mabogunje, A Matson, P Mooney, H Moore, B O'Riordan, T Svedin, U AF Kates, RW Clark, WC Corell, R Hall, JM Jaeger, CC Lowe, I McCarthy, JJ Schellnhuber, HJ Bolin, B Dickson, NM Faucheux, S Gallopin, GC Grubler, A Huntley, B Jager, J Jodha, NS Kasperson, RE Mabogunje, A Matson, P Mooney, H Moore, B O'Riordan, T Svedin, U TI Environment and development - Sustainability science SO SCIENCE LA English DT Editorial Material ID MANAGEMENT C1 Harvard Univ, John F Kennedy Sch Govt, Cambridge, MA 02138 USA. Amer Meteorol Soc, Washington, DC 20005 USA. NOAA, Silver Spring, MD 20910 USA. Potsdam Inst Climate Imapct Res, D-14412 Potsdam, Germany. Griffith Univ, Nathan, Qld 4111, Australia. Stockholm Univ, S-18451 Stockholm, Sweden. Univ Versailles, Ctr Econ & Eth Environm & Dev, F-78047 Guyancourt, France. Econ Commiss Latin Amer & Caribbean, Santiago, Chile. Int Inst Appl Syst Anal, A-2361 Laxenburg, Austria. Natl Bot Inst, ZA-7735 Cape Town, South Africa. Int Human Dimens Programme Global Environm Change, D-53113 Bonn, Germany. Int Ctr Integrated Mt Dev, Kathmandu, Nepal. Stockholm Environm Inst, S-10314 Stockholm, Sweden. Stanford Univ, Stanford, CA 94305 USA. Univ New Hampshire, Inst Earth Oceans & Space, Durham, NH 03824 USA. Univ E Anglia, Ctr Social & Econ Res Global Environm, Norwich NR4 7TJ, Norfolk, England. Swedish Council Planning & Coordinat Res FRN, S-10387 Stockholm, Sweden. Dev Policy Ctr, Ibadan, Nigeria. RP Clark, WC (reprint author), Harvard Univ, John F Kennedy Sch Govt, Cambridge, MA 02138 USA. RI Schellnhuber, Hans Joachim/B-2607-2012; Clark, William/A-4832-2008; OI Schellnhuber, Hans Joachim/0000-0001-7453-4935; Grubler, Arnulf/0000-0002-6225-7712; O'Riordan, Timothy/0000-0002-0492-8477 NR 25 TC 874 Z9 992 U1 32 U2 366 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 APR 27 PY 2001 VL 292 IS 5517 BP 641 EP 642 DI 10.1126/science.1059386 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 428TX UT WOS:000168478300024 PM 11330321 ER PT J AU Ryerson, TB Trainer, M Holloway, JS Parrish, DD Huey, LG Sueper, DT Frost, GJ Donnelly, SG Schauffler, S Atlas, EL Kuster, WC Goldan, PD Hubler, G Meagher, JF Fehsenfeld, FC AF Ryerson, TB Trainer, M Holloway, JS Parrish, DD Huey, LG Sueper, DT Frost, GJ Donnelly, SG Schauffler, S Atlas, EL Kuster, WC Goldan, PD Hubler, G Meagher, JF Fehsenfeld, FC TI Observations of ozone formation in power plant plumes and implications for ozone control strategies SO SCIENCE LA English DT Article ID UNITED-STATES; EMISSIONS; HYDROCARBONS; TROPOSPHERE; NO2; POLLUTION; CHEMISTRY; ATLANTA; MODELS; O-3 AB Data taken in aircraft transects of emissions plumes from rural U.S. coal-fired power plants were used to confirm and quantify the nonlinear dependence of tropospheric ozone formation on plume NOx (NO plus NO2) concentration, which is determined by plant NOx emission rate and atmospheric dispersion. The ambient availability of reactive volatile organic compounds, principally biogenic isoprene, was also found to modulate ozone production rate and yield in these rural plumes. Differences of a factor of 2 or greater in plume ozone formation rates and yields as a function of NOx and volatile organic compound concentrations were consistently observed. These large differences suggest that consideration of power plant NOx emission rates and geographic locations in current and future U.S. ozone control strategies could substantially enhance the efficacy of NOx reductions from these sources. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. RP Ryerson, TB (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Kuster, William/E-7421-2010; Hubler, Gerhard/E-9780-2010; Parrish, David/E-8957-2010; Holloway, John/F-9911-2012; Trainer, Michael/H-5168-2013; Ryerson, Tom/C-9611-2009; Frost, Gregory/I-1958-2013; Fehsenfeld, Frederick/I-4876-2013; Atlas, Elliot/J-8171-2015 OI Kuster, William/0000-0002-8788-8588; Parrish, David/0000-0001-6312-2724; Holloway, John/0000-0002-4585-9594; NR 24 TC 162 Z9 170 U1 3 U2 51 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 APR 27 PY 2001 VL 292 IS 5517 BP 719 EP 723 DI 10.1126/science.1058113 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 428TX UT WOS:000168478300049 PM 11326097 ER PT J AU Pochan, DJ Lin, EK Satija, SK Wu, WL AF Pochan, DJ Lin, EK Satija, SK Wu, WL TI Thermal expansion of supported thin polymer films: A direct comparison of free surface vs total confinement SO MACROMOLECULES LA English DT Article ID GLASS-TRANSITION TEMPERATURE; X-RAY REFLECTIVITY; POLYSTYRENE FILMS; LIGHT-SCATTERING; INTERFACE; POLYIMIDES; MOBILITY; PROBE AB Neutron reflectivity measurements on deuterated polystyrene (dPS) thin films reveal a strong dependence of the coefficient of thermal expansion (CTE) on both the thickness of the film and the specific confinement boundaries. A direct comparison is made between films on low energy, fluorinated polyimide (fPI) substrates with a free surface (bilayer) and the same films after capping the bilayer with another fPI layer (trilayer). For bilayers, a significant decrease in alpha (r), the CTE above the bulk glass transition temperature, is observed in dPS with thicknesses d < 35 nm. For trilayers, a decrease of a,is observed at larger film thicknesses, d < 60 nm. Replacing the fPI substrate with an SiOx substrate, alpha (r) remains bulklike, showing that the length scale for deviations from bulk behavior is sensitive to the specific confining boundaries. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Pochan, DJ (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 31 TC 48 Z9 48 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 24 PY 2001 VL 34 IS 9 BP 3041 EP 3045 DI 10.1021/ma001253f PG 5 WC Polymer Science SC Polymer Science GA 424MT UT WOS:000168236600043 ER PT J AU Holmes, EE AF Holmes, EE TI Estimating risks in declining populations with poor data SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID TIME-SERIES; EXTINCTION; PROBABILITY; MEANINGFUL; MODELS; ERRORS AB Census data on endangered species are often sparse, error-ridden, and confined to only a segment of the population. Estimating trends and extinction risks using this type of data presents numerous difficulties. In particular, the estimate of the variation in year-to-year transitions in population size (the "process error" caused by stochasticity in survivorship and fecundities) is confounded by the addition of high sampling error variation. In addition, the year-to-year variability in the segment of the population that is sampled may be quite different from the population variability that one is trying to estimate. The combined effect of severe sampling error and age- or stage-specific counts leads to severe biases in estimates of population-level parameters. I present an estimation method that circumvents the problem of age- or stage-specific counts and is markedly robust to severe sampling error. This method allows the estimation of environmental variation and population trends for extinction-risk analyses using corrupted census counts-a common type of data for endangered species that has hitherto been relatively unusable for these analyses. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Resource Enhancement & Utilizat Technol Div, Seattle, WA 98112 USA. RP Holmes, EE (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Resource Enhancement & Utilizat Technol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 18 TC 101 Z9 107 U1 3 U2 23 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 APR 24 PY 2001 VL 98 IS 9 BP 5072 EP 5077 DI 10.1073/pnas.081055898 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 425VC UT WOS:000168311500050 PM 11309483 ER PT J AU Maier, R Cohn, JL Neumeier, JJ Bendersky, LA AF Maier, R Cohn, JL Neumeier, JJ Bendersky, LA TI Ferroelectricity and ferrimagnetism in iron-doped BaTiO3 SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILMS; TEMPERATURE; DEPOSITION AB The structural and physical properties of pseudocubic thin-film BaTi1-xFexO3(0.5 less than or equal tox less than or equal to0.75) grown by pulsed-laser deposition are reported. This material is of interest because the corresponding bulk compounds have hexagonal structure for comparable x, and because the films are both ferroelectric and ferrimagnetic well above room temperature. A substantial increase of the ferroelectric transition temperature relative to that of bulk BaTiO3 is attributed to lattice expansion induced by Fe doping. (C) 2001 American Institute of Physics. C1 Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. Florida Atlantic Univ, Dept Phys, Boca Raton, FL 33431 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Maier, R (reprint author), Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. NR 25 TC 59 Z9 62 U1 3 U2 25 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 23 PY 2001 VL 78 IS 17 BP 2536 EP 2538 DI 10.1063/1.1367311 PG 3 WC Physics, Applied SC Physics GA 425RC UT WOS:000168304600041 ER PT J AU Coxon, B Reynolds, RC AF Coxon, B Reynolds, RC TI Boat conformations part IV - Synthesis, NMR spectroscopy, and molecular dynamics of methyl 4,6-O-benzylidene-3-deoxy-3-phthalimido-alpha-D-altropyranoside derivatives SO CARBOHYDRATE RESEARCH LA English DT Article DE altropyranoside; boat conformations; H-1 NMR spectroscopy; molecular dynamics; phthalimido derivative; simulated annealing; skew boat conformations; vicinal coupling constants ID H-1-NMR AB Addition of the elements of phthalimide to methyl 2,3-anhydro-4,6-O-benzylidene-alpha -D-mannopyranoside (1) under fusion conditions has yielded methyl 4,6-O-benzylidene-3-deoxy-3-phthalimido-alpha -D-altropyranoside (2). The conformation of the pyranose ring of 2 has been shown to be non-chair by H-1 NMR spectroscopy, in contrast to the conformations of related derivatives having smaller substituents at C-3. Molecular dynamics simulations of 2 in explicit chloroform-d solvent have indicated four principal conformational possibilities. Of these, the C-7(5)/S-1(5) chair/skew boat form 2d has the lowest potential energy, and is largely consistent with the observed vicinal H-1-H-1 NMR coupling constants. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 NICHHD, NIH, Bethesda, MD 20892 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Coxon, B (reprint author), NICHHD, NIH, 6 Ctr Dr,MSC 2720, Bethesda, MD 20892 USA. NR 17 TC 8 Z9 9 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0008-6215 J9 CARBOHYD RES JI Carbohydr. Res. PD APR 23 PY 2001 VL 331 IS 4 BP 461 EP 467 DI 10.1016/S0008-6215(01)00036-2 PG 7 WC Biochemistry & Molecular Biology; Chemistry, Applied; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA 427BC UT WOS:000168384100012 PM 11398989 ER PT J AU Leo, PJ Julienne, PS Mies, FH Williams, CJ AF Leo, PJ Julienne, PS Mies, FH Williams, CJ TI Collisional frequency shifts in Cs-133 fountain clocks SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN CONDENSATION; CESIUM FOUNTAIN; ATOMS; SCATTERING; RESONANCE; STANDARD AB Wie present a theoretical analysis of the density dependent frequency shift in Cs fountain clocks using the highly constrained binary collision model described by Leo et al. [Phys. Rev Lett. 85, 2721 (2000)]. We predict a reversal in the clock shift at temperatures near 0.08 muK. OUT results show that s waves; dominate the collision process. However, as a consequence of the large scattering lengths in Ca the clock shift is strongly temperature dependent and does not reach a constant Wigner-law value until temperatures are less than 0.1 nK. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Leo, PJ (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Williams, Carl/B-5877-2009; Leo, Paul/B-3470-2011; Julienne, Paul/E-9378-2012 OI Leo, Paul/0000-0001-8325-4134; Julienne, Paul/0000-0002-5494-1442 NR 28 TC 52 Z9 52 U1 3 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 23 PY 2001 VL 86 IS 17 BP 3743 EP 3746 DI 10.1103/PhysRevLett.86.3743 PG 4 WC Physics, Multidisciplinary SC Physics GA 426FC UT WOS:000168338300012 PM 11329313 ER PT J AU Killian, TC Lim, MJ Kulin, S Dumke, R Bergeson, SD Rolston, SL AF Killian, TC Lim, MJ Kulin, S Dumke, R Bergeson, SD Rolston, SL TI Formation of Rydberg atoms in an expanding ultracold neutral plasma SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON-ION RECOMBINATION; VERY-LOW ENERGIES; 3-BODY RECOMBINATION; EXPANSION; ANTIHYDROGEN; VACUUM; RATES; STATE AB We study the formation of Rydberg atoms in expanding plasmas at temperatures of 1-1000 K and densities from 10(5)-10(10) cm(-3). Up to 20% of the initially free charges recombine in about 100 mus, and the binding energy of the Rydberg atoms approximately equals the increase in the kinetic enemy of the remaining free electrons. Three-body recombination is expected to dominate in this regime, yet most of our results are inconsistent with this mechanism. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Killian, TC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI rolston, steven/L-5175-2013; Bergeson, Scott/L-8959-2013 OI rolston, steven/0000-0003-1671-4190; Bergeson, Scott/0000-0002-3124-9226 NR 27 TC 199 Z9 201 U1 3 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 23 PY 2001 VL 86 IS 17 BP 3759 EP 3762 DI 10.1103/PhysRevLett.86.3759 PG 4 WC Physics, Multidisciplinary SC Physics GA 426FC UT WOS:000168338300016 PM 11329317 ER PT J AU Arp, U AF Arp, U TI Diffraction and depths-of-field effects in electron beam imaging at SURF III SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE electron beam diagnostics; transverse beam size; diffraction; depth of field; synchrotron radiation; storage ring ID SYNCHROTRON RADIATION; OPTICAL RESOLUTION AB Imaging an electron beam with visible light is a common method of diagnostics applied to electron accelerators. It is a straightforward way to deduce the transverse electron distribution as well as its changes over time. The electrons stored in the Synchrotron Ultraviolet Radiation Facility (SURF) III at the National Institute of Standards and Technology (NIST) were studied over an extended period of time to characterize the upgraded accelerator. There is good agreement between experimental and theoretical horizontal beam sizes at three different electron energies. (C) 2001 Elsevier Science B.V. All rights reserved. C1 NIST, SURF, Gaithersburg, MD 20899 USA. RP Arp, U (reprint author), NIST, SURF, 100 Bur Dr,MS 8410, Gaithersburg, MD 20899 USA. RI Arp, Uwe/C-2854-2009; OI Arp, Uwe/0000-0002-6468-9455 NR 13 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 2001 VL 462 IS 3 BP 568 EP 575 DI 10.1016/S0168-9002(00)01328-0 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 435MU UT WOS:000168885900026 ER PT J AU Sansonetti, CJ Reader, J Vogler, K AF Sansonetti, CJ Reader, J Vogler, K TI Precision measurement of wavelengths emitted by a molecular fluorine laser at 157 nm SO APPLIED OPTICS LA English DT Article ID F2 LASER; SHIFTS AB The wavelengths of six spectral lines emitted by a molecular fluorine (F-2) laser at 157 nm were measured to high accuracy with the 10.7-m normal-incidence vacuum spectrograph at the National Institute of Standards and Technology. Lines from a Pt-Ne hollow-cathode lamp served as the wavelength standards. Spectra of the laser and the Pt-Ne lamp were photographed simultaneously through an uncoated CaF2 beam splitter. The optical paths were arranged so as to avoid shifts in line positions arising from possible differences in illumination of the grating by the two sources. The strongest lasing line was found to have a wavelength of 157.63094(10) nm. Changes in wavelength for variations in gas mixture, total gas pressure, and voltage were also measured. C1 Natl Inst Stand & Technol, Atom Spect Grp, Gaithersburg, MD 20899 USA. Lambda Phys Corp, Gottingen, Germany. RP Sansonetti, CJ (reprint author), Natl Inst Stand & Technol, Atom Spect Grp, Gaithersburg, MD 20899 USA. EM craig.sansonetti@nist.gov NR 14 TC 21 Z9 21 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD APR 20 PY 2001 VL 40 IS 12 BP 1974 EP 1978 DI 10.1364/AO.40.001974 PG 5 WC Optics SC Optics GA 421RD UT WOS:000168076600014 PM 18357199 ER PT J AU Orr, JW Busby, MS AF Orr, JW Busby, MS TI Prognatholiparis ptychomandibularis, a new genus and species of the fish family Liparidae (Teleostei : Scorpaeniformes) from the Aleutian Islands, Alaska SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB A new species representing a monotypic genus of liparid fishes is described from the central Aleutian Islands. The new genus differs from all known liparid genera by its strongly protruding lower jaw and prominent folds and flaps of skin on the jaws and snout. It is similar to Allocareproctus jordani and Careproctus pycnosoma, which are also moderately slender liparids with large pelvic disks, but it is further distinguished from these species by its lower meristics, more slender body, and absence of pyloric caeca. Ptychomandibularis also differs from Allocareproctus in its possession of an eighth preoperculomandibular pore, absence of coronal and post-coronal pores, two epurals, and autogenous hypural plates. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Resource Assessment & Conservat Engn Div, Seattle, WA 98115 USA. RP Orr, JW (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Resource Assessment & Conservat Engn Div, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 10 TC 5 Z9 5 U1 0 U2 3 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 APR 19 PY 2001 VL 114 IS 1 BP 51 EP 57 PG 7 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 428MG UT WOS:000168465000004 ER PT J AU Redfield, S Linsky, JL AF Redfield, S Linsky, JL TI Microstructure of the Local Interstellar Cloud and the identification of the Hyades cloud SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : atoms; ISM : clouds; ISM : structure; stars : chromospheres; ultraviolet : ISM; ultraviolet : stars ID LATE-TYPE STARS; ALPHA ABSORPTION; SPACE-TELESCOPE; CANIS-MAJORIS; D/H RATIO; SIRIUS-A; HST-GHRS; SIGHT; GAS; DEUTERIUM AB We analyze high-resolution UV spectra of the Mg II h and k lines for 18 members of the Hyades to study inhomogeneity along these proximate lines of sight. The observations were taken by the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope (HST). Three distinct velocity components are observed. All 18 lines of sight show absorption by the Local Interstellar Cloud (LIC); 10 stars show absorption by an additional cloud, which we name the Hyades Cloud; and one star exhibits a third absorption component. The LIC absorption is observed at a lower radial velocity than predicted by the LIC velocity vector derived by Lallement & Bertin in 1992 and Lallement et al. in 1995 [upsilon (predicted)(LIC) - upsilon (observed)(LIC) = 2.9 +/- 0.7 km s(-1)], which may indicate a compression or deceleration at the leading edge of the LIC. We propose an extension of the Hyades Cloud boundary based on previous HST observations of other stars in the general vicinity of the Hyades, as well as groundbased Ca II observations. We present our fits of the interstellar parameters for each absorption component. The availability of 18 similar lines of sight provides an excellent opportunity to study the inhomogeneity of the warm, partially ionized local interstellar medium (LISM). We find that these structures are roughly homogeneous. The measured Mg II column densities do not vary by more than a factor of 2 for angular separations of less than or similar to8 degrees, which at the outer edge of the LIC correspond to physical separations of less than or similar to0.6 pc. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Redfield, S (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 48 TC 38 Z9 38 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 18 PY 2001 VL 551 IS 1 BP 413 EP 428 DI 10.1086/320096 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 423AF UT WOS:000168152200035 ER PT J AU Harper, GM Wilkinson, E Brown, A Jordan, C Linsky, JL AF Harper, GM Wilkinson, E Brown, A Jordan, C Linsky, JL TI Identification of FeII emission lines in FUSE stellar spectra SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : formation; line : identification; stars : chromospheres; stars : individual (alpha Trianguli Australis, HD 104237); ultraviolet : stars ID OUTER ATMOSPHERE; ALPHA-TAU; ULTRAVIOLET-SPECTRUM; GHRS OBSERVATIONS; BRIGHT GIANTS; COOL STARS; EXCITATION; WIND AB We identify two complexes of Fe II emission lines in far-ultraviolet spectra of the stars alpha TrA and HD 104237. Using spectra from both the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST), we show that these emission lines, which represent the majority of previously unidentified emission features in cool star spectra between 912 and 1180 Angstrom, are fluorescent decays in Fe II following excitation by H Ly alpha. Specifically, following photoexcitation from the third term (4s a D-4) of Fe II, subsequent decays are observed to the two lowest terms (4s a D-6 and 3d(7) a F-4) which are observed near 1100 and 1135 Angstrom, respectively. Decays to higher terms, and hence longer wavelengths, also are clearly seen in the STIS spectra. Differences in the fluorescent Fe II spectra of alpha TrA and HD 104237 are tentatively identified as resulting from differences in the intrinsic width of the density-weighted H Ly alpha radiation fields. The additional Fe II lines observed in alpha TrA result from a broadened H Ly alpha profile. Two features near 1060 Angstrom appear to be fluorescent lines of Cr II, also excited by H Ly alpha. C1 Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Univ Oxford, Dept Phys Teoret Phys, Oxford OX1 3NP, England. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Harper, GM (reprint author), Univ Colorado, Ctr Astrophys & Space Astron, 389 UCB, Boulder, CO 80309 USA. NR 36 TC 25 Z9 25 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 18 PY 2001 VL 551 IS 1 BP 486 EP 494 DI 10.1086/320088 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 423AF UT WOS:000168152200041 ER PT J AU Muller, HR Zank, GP Wood, BE AF Muller, HR Zank, GP Wood, BE TI Modeling the interstellar medium-stellar wind interactions of lambda Andromedae and epsilon Indi SO ASTROPHYSICAL JOURNAL LA English DT Article DE hydrodynamics; stars : individual (epsilon Indi, lambda Andromedae); stars : winds, outflows; ultraviolet : ISM ID LY-ALPHA ABSORPTION; SOLAR-WIND; HYDROGEN; GAS; HELIOSPHERE; CENTAURI AB A numerical study is presented of the interaction between the partially ionized interstellar medium (ISM) and the stellar wind of the very active RS CVn-type binary star lambda And (G8 IV-III + ?). Similar to results found for the heliosphere-ISM interaction, a termination shock, a tangential discontinuity (the "astropause"), and a flow shock are found in the model. More importantly, a hydrogen wall forms in the model, and its neutral density, temperature, and velocity are investigated. As an application, the additional absorption of the Ly alpha line of lambda And due to the hydrogen wall is calculated and compared with high-resolution UV spectra obtained by the Hubble Space Telescope (HST). Variation of stellar wind parameters results in different astrospheres and hydrogen walls, with distinct Ly alpha absorption. Although not studied here, variation of interstellar parameters will alter the astrospheres as well, just as in the heliospheric case. Thus, establishing a good model fit to the HST data is a tool to constrain the combination of parameters of stellar wind and ambient interstellar medium. A second numerical study is undertaken for the nearby star epsilon Ind (K5 V). Again, a hydrogen wall is encountered, and the correction to interstellar Ly alpha absorption demonstrated. While epsilon Ind is interesting in that it has a high relative velocity with respect to the ISM, lambda And is interesting in that it is a large, extremely active star that we therefore model with a higher mass-loss rate than the Sun. The numerous assumptions that are made in the models preclude a definitive measurement of mass-loss rates for these stars at this point, but our models suggest that for epsilon Ind the observed Ly alpha absorption can be reproduced adequately by a wind with roughly the solar mass-loss rate. For lambda And, a mass-loss rate of roughly 10 times solar is suggested, which is actually lower than one might have expected since the star has about 55 times the surface area of the Sun. C1 Univ Delaware, Bartol Res Inst, Sharp Lab 217, Newark, DE 19716 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Univ Delaware, Bartol Res Inst, Sharp Lab 217, Newark, DE 19716 USA. EM mueller@bartol.udel.edu; zank@bartol.udel.edu; woodb@casa.colorado.edu NR 24 TC 18 Z9 18 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD APR 18 PY 2001 VL 551 IS 1 BP 495 EP 506 DI 10.1086/320070 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 423AF UT WOS:000168152200042 ER PT J AU Wahlgren, GM Brage, T Brandt, JC Fleming, J Johansson, S Leckrone, DS Proffitt, CR Reader, J Sansonetti, CJ AF Wahlgren, GM Brage, T Brandt, JC Fleming, J Johansson, S Leckrone, DS Proffitt, CR Reader, J Sansonetti, CJ TI The bismuth abundance in the HgMn stars chi Lupi and HR 7775 and improved atomic data for selected transitions of BiI, BiII, and BiIII SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; stars : abundances; stars : chemically peculiar; stars : individual (chi Lupi, HR 7775); ultraviolet : stars ID OSCILLATOR-STRENGTHS; PATHFINDER PROJECT; ELEMENTS; PLATINUM; SPECTROSCOPY; DIFFUSION; ENVELOPES; SPECTRUM; PACKAGE; PROGRAM AB High-resolution spectra of the chemically peculiar HgMn stars chi Lupi and HR 7775, obtained with the Hubble Space Telescope/Goddard High Resolution Spectrograph, are investigated for their abundance of bismuth by comparison with LTE synthetic spectrum modeling. HR 7775, previously known from International Ultraviolet Explorer spectra to display strong lines of Bi II, is determined to have bismuth present at an enhancement level of nearly 5 orders of magnitude from the lines Bi II lambda lambda 1436, 1902 and Bi III lambda 1423. The bismuth enhancement for chi Lupi is found to be near a level of 1.5 dex, and an ionization anomaly between Bi+ and Bi++ is apparent. HR 7775 abundance enhancements of the heavy elements platinum, [Pt/H] = 4.7 dex, and gold, [Au/H] = 3.8 dex, have also been determined. New laboratory measurements for wavelengths and hyperfine structure patterns of Bi I/Bi II/Bi III lines are presented, as well as the results of calculations for hyperfine structure constants and oscillator strengths for selected lines of Bi II and Bi III. C1 Univ Lund, Dept Phys, S-22100 Lund, Sweden. NASA, Goddard Space Flight Ctr, Comp Sci Corp, Sci Program, Greenbelt, MD 20771 USA. Univ Colorado, Lab Astron & Space Phys, Boulder, CO 80309 USA. Queens Univ Belfast, Dept Appl Math, Belfast BT7 1NN, Antrim, North Ireland. Univ Lund, Lund Observ, S-22100 Lund, Sweden. NASA, Goddard Space Flight Ctr, Hubble Space Telescope Project, Greenbelt, MD 20771 USA. Comp Sci Corp, Sci Program, Baltimore, MD 21218 USA. Catholic Univ Amer, Dept Phys, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Wahlgren, GM (reprint author), Univ Lund, Dept Phys, Box 118, S-22100 Lund, Sweden. NR 44 TC 17 Z9 17 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 18 PY 2001 VL 551 IS 1 BP 520 EP 535 DI 10.1086/320063 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 423AF UT WOS:000168152200045 ER PT J AU Evmenenko, G Bauer, BJ Kleppinger, R Forier, B Dehaen, W Amis, EJ Mischenko, N Reynaers, H AF Evmenenko, G Bauer, BJ Kleppinger, R Forier, B Dehaen, W Amis, EJ Mischenko, N Reynaers, H TI The influence of molecular architecture and solvent type on the size and structure of poly(benzyl ether) dendrimers by SANS SO MACROMOLECULAR CHEMISTRY AND PHYSICS LA English DT Article ID ANGLE NEUTRON-SCATTERING; DENDRITIC MACROMOLECULES; CONVERGENT APPROACH; PAMAM DENDRIMERS; POLYMERS; DYNAMICS; POLYETHERS; REACTIVITY; BEHAVIOR; QUALITY C1 Catholic Univ Louvain, Dept Chem, Lab Macromol Struct Chem, B-3001 Heverlee, Belgium. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Catholic Univ Louvain, Dept Chem, Organ Synth Lab, B-3001 Heverlee, Belgium. RP Reynaers, H (reprint author), Catholic Univ Louvain, Dept Chem, Lab Macromol Struct Chem, Celestijnenlaan 200F, B-3001 Heverlee, Belgium. NR 42 TC 27 Z9 27 U1 1 U2 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 1022-1352 J9 MACROMOL CHEM PHYSIC JI Macromol. Chem. Phys. PD APR 18 PY 2001 VL 202 IS 6 BP 891 EP 899 DI 10.1002/1521-3935(20010301)202:6<891::AID-MACP891>3.0.CO;2-K PG 9 WC Polymer Science SC Polymer Science GA 429EX UT WOS:000168504000017 ER PT J AU Jaffe, D Anderson, T Covert, D Trost, B Danielson, J Simpson, W Blake, D Harris, J Streets, D AF Jaffe, D Anderson, T Covert, D Trost, B Danielson, J Simpson, W Blake, D Harris, J Streets, D TI Observations of ozone and related species in the northeast Pacific during the PHOBEA campaigns 1. Ground-based observations at Cheeka Peak SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LONG-RANGE TRANSPORT; MAUNA-LOA; ASIAN EMISSIONS; CARBON-MONOXIDE; ATLANTIC REGION; UNITED-STATES; SURFACE OZONE; NOX; CO; NITRATE AB As part of the Photochemical Ozone Budget of the Eastern North Pacific Atmosphere (PHOBEA) project, we made observations of CO, O3, NOx, peroxyacetyl nitrate (PAN), nonmethane hydrocarbons (NMHC), Rn, aerosol scattering, aerosol absorption, and aerosol number density during the springs of 1997 and 1998 at the Cheeka Peak Observatory (CPO) on the western tip of Washington State. The data have been segregated to quantify the mixing ratio of these species in the Pacific marine atmosphere. However, even in these marine air masses, there are occasionally substantial enhancements of NOx and aerosols, but not CO, which we attribute to diesel exhaust from ship traffic to and from major ports in the region. The marine air masses were further classified into four categories based on 10-day back isentropic trajectories; high, mid, and low latitude and those which had crossed over the Asian industrial region. Mean marine mixing ratios in 1998 were significantly higher then the 1997 values for CO (1997 mean equal to 151, 1998 mean equal to 170 ppbv), ethane (1771, 1968 parts per trillion by volume (pptv)), and ethyne (306, 452 pptv). Also, segregation of the 1998 data by air mass origin produced smaller differences in the mixing ratios for most species when comparing different source regions. We attribute both of these results to elevated emissions associated with unusually large areas of biomass burning which took place in Indonesia and Siberia during late 1997 and 1998. The relative enhancements of CO, ethane, ethyne, and propane we observed at CPO are consistent with enhanced biomass burning and industrial sources in the spring of 1998, relative to the spring of 1997. C1 Univ Washington, Bothell, WA 98021 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Univ Alaska, Dept Chem, Fairbanks, AK 99775 USA. Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92717 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Jaffe, D (reprint author), Univ Washington, Bothell, WA 98021 USA. RI Simpson, William/I-2859-2014; OI Simpson, William/0000-0002-8596-7290; Streets, David/0000-0002-0223-1350 NR 56 TC 65 Z9 64 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 16 PY 2001 VL 106 IS D7 BP 7449 EP 7461 DI 10.1029/2000JD900636 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 423QZ UT WOS:000168189400019 ER PT J AU Kotchenruther, RA Jaffe, DA Beine, HJ Anderson, TL Bottenheim, JW Harris, JM Blake, DR Schmitt, R AF Kotchenruther, RA Jaffe, DA Beine, HJ Anderson, TL Bottenheim, JW Harris, JM Blake, DR Schmitt, R TI Observations of Ozone and related species in the northeast Pacific during the PHOBEA campaigns 2. Airborne observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PEM-WEST-B; UNITED-STATES; CHEMICAL CHARACTERISTICS; FUEL COMBUSTION; ASIAN EMISSIONS; AIR; OCEAN; NOX; PHOTOCHEMISTRY; HYDROCARBONS AB During late March and April of 1999 the University of Wyoming's King Air research aircraft measured atmospheric concentrations of NO, O-3, peroxyacetyl nitrate (PAN), CO, CH4, VOCs, aerosols, and J(NO2) off the west coast df the United States. During 14 flights, measurements were made between 39 degrees -48 degreesN latitude, 125 degrees -129 degreesW longitude, and at altitudes from 0-8 km. These flights were part of the Photochemical Ozone Budget of the Eastern North Pacific Atmosphere (PHOBEA) experiment, which included both groundbased and airborne measurements. Flights were scheduled when meteorological conditions minimized the impact of local pollution sources. The resulting measurements were segregated by air mass source region as indicated by back isentropic trajectory analysis. The chemical composition of marine air masses whose 5-day back isentropic trajectories originated north df 40 degreesN latitude or west of 186 degreesW longitude (WNW) differed significantly from marine air masses whose 5-day back isentropic trajectories originated south of 40 degreesN latitude and east of 180 degreesW longitude (SW). Trajectory and chemical analyses indicated that the majority of all encountered air masses, both WNW and SW, likely originated from the northwestern Pacific and have characteristics of emissions from the East Asian continental region. However, air masses with WNW back trajectories contained higher mixing ratios of NO, NOx, O-3, PAN, CO, CH4, various VOC pollution tracers, and aerosol number concentration, compared to those air masses with SW back trajectories. Calculations of air mass age using two separate methods, photochemical and back trajectory, are consistent with transport from the northwestern Pacific in 8-10 days for air masses with WNW back trajectories and 16-20 days for air masses with SW back trajectories. Correlations, trajectory analysis, and comparisons with measurements made in the northwestern Pacific during NASA's Pacific Exploritory Mission-West Phase B (PEM-West B) experiment in 1994 are used to investigate the data. These analyses provide evidence that anthropogenically influenced air masses from the northwestern Pacific affect the overall chemical composition of the northeastern Pacific troposphere. C1 Univ Washington, Dept Chem, Seattle, WA 98195 USA. Univ Washington, Bothell, WA 98021 USA. CNR, Ist Inquinamento Atmosfer, I-00016 Monterotondo, Italy. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Atmospher Environm Serv, Toronto, ON M3H 5T4, Canada. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92717 USA. Meteorol Consult GmbH, D-61479 Glashutten, Germany. RP Kotchenruther, RA (reprint author), Univ Washington, Dept Chem, Seattle, WA 98195 USA. NR 39 TC 38 Z9 38 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 16 PY 2001 VL 106 IS D7 BP 7463 EP 7483 DI 10.1029/2000JD900425 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 423QZ UT WOS:000168189400020 ER PT J AU Schulz, A Rex, M Harris, NRP Braathern, GO Reimer, E Alfier, R Kilbane-Dawe, I Eckermann, S Allaart, M Alpers, M Bojkov, B Cisneros, J Claude, H Cuevas, E Davies, J De Backer, H Dier, H Dorokhov, V Fast, H Godin, S Johnson, B Kois, B Kondo, Y Kosmidis, E Kyro, E Litynska, Z Mikkelsen, IS Molyneux, MJ Murphy, G Nagai, T Nakane, H O'Connor, F Parrondo, C Schmidlin, FJ Skrivankova, P Varotsos, C Vialle, C Viatte, P Yushkov, V Zerefos, C von der Gathen, P AF Schulz, A Rex, M Harris, NRP Braathern, GO Reimer, E Alfier, R Kilbane-Dawe, I Eckermann, S Allaart, M Alpers, M Bojkov, B Cisneros, J Claude, H Cuevas, E Davies, J De Backer, H Dier, H Dorokhov, V Fast, H Godin, S Johnson, B Kois, B Kondo, Y Kosmidis, E Kyro, E Litynska, Z Mikkelsen, IS Molyneux, MJ Murphy, G Nagai, T Nakane, H O'Connor, F Parrondo, C Schmidlin, FJ Skrivankova, P Varotsos, C Vialle, C Viatte, P Yushkov, V Zerefos, C von der Gathen, P TI Arctic ozone loss in threshold conditions: Match observations in 1997/1998 and 1998/1999 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WINTER; DEPLETION; STRATOSPHERE; VORTEX AB Chemical ozone loss rates inside the Arctic polar vortex were determined in early 1998 and early 1999 by using the Match technique based on coordinated ozonesonde measurements. These two winters provide the only opportunities in recent years to investigate chemical ozone loss in a warm Arctic vortex under threshold conditions, i.e., where the preconditions for chlorine activation, and hence ozone destruction, only occurred occasionally. In 1998, results were obtained in January and February between 410 and 520 K. The overall ozone loss was observed to be largely insignificant; with the exception of late February, when those air parcels exposed to temperatures below 195 K were affected by chemical ozone loss. In 1999, results are confined to the 475 K isentropic level, where no significant ozone loss was observed. Average temperatures were some 8 degrees - 10 degrees higher than those in 1995, 1996, and 1997, when substantial chemical ozone loss occurred. The results underline the strong dependence of the chemical ozone loss on the stratospheric temperatures. This study shows that enhanced chlorine alone does not provide a sufficient condition for ozone loss. The evolution of stratospheric temperatures over the next decade will be the determining factor for the amount of wintertime chemical ozone loss in the Arctic stratosphere. C1 Alfred Wegener Inst Polar & Marine Res, D-14401 Potsdam, Germany. European Ozone Res Coordinating Unit, Cambridge CB2 1EW, England. Norwegian Inst Air Res, Kjeller, Norway. FU Berlin, Inst Meteorol, D-12165 Berlin, Germany. USN, Res Lab, Washington, DC 20375 USA. Royal Netherlands Meteorol Inst, NL-3730 AE De Bilt, Netherlands. Leibniz Inst Atmospher Phys, D-18221 Kuhlungsborn, Germany. Inst Nacl Meteorol, Madrid 28071, Spain. Deutsch Wetterdienst, Observ Hohenpeissenberg, D-82383 Hohenpeissenberg, Germany. Inst Nacl Meteorol, Tenerife, Spain. Atmospher Environm Serv, Downsview, ON M3H 5T4, Canada. Royal Meteorol Inst, B-1180 Brussels, Belgium. Meteorol Observ Lindenberg, D-15864 Lindenberg, Germany. Cent Aerol Observ, Dolgoprudnyi 141700, Moscow Region, Russia. Univ Paris 06, Serv Aeron, CNRS, F-75230 Paris 05, France. NOAA, Climate Monitoring & Diagnost Lab, Ozone & Water Vapour Grp, Boulder, CO 80303 USA. Ctr Aerol, Inst Meteorol & Water Management, PL-95119 Legionowo, Poland. Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. Univ Thessaloniki, Lab Atmospher Phys, Salonika 45006, Greece. Sodankyla Meteorol Observ, Sodankyla 99600, Finland. Danish Meteorol Inst, DK-2100 Copenhagen, Denmark. Meteorol Off, Wokingham RG40 3DN, Berks, England. Irish Meteorol Serv, Valentia Observ, Cahirciveen, County Kerry, Ireland. Meteorol Res Inst, Tsukuba, Ibaraki 3050052, Japan. Natl Inst Environm Studies, Tsukuba, Ibaraki 3050053, Japan. Inst Nacl Tecn Aerosp, Madrid 28850, Spain. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Island, VA 23337 USA. Czech Hydrometeorol Inst, Uppsala Air & Surface Observat Dept, Prague 14306, Czech Republic. Univ Athens, Dept Appl Phys, Athens 15784, Greece. Inst Pierre Simon Laplace, Serv Observat, F-91371 Verrieres Buisson, France. Swiss Meteorol Inst, CH-1530 Payerne, Switzerland. RP Schulz, A (reprint author), Alfred Wegener Inst Polar & Marine Res, POB 600149, D-14401 Potsdam, Germany. RI Rex, Markus/A-6054-2009; von der Gathen, Peter/B-8515-2009; Kondo, Yutaka/D-1459-2012; Varotsos, Costas/H-6257-2013; Cuevas, Emilio/L-2109-2013; OI Rex, Markus/0000-0001-7847-8221; von der Gathen, Peter/0000-0001-7409-1556; Varotsos, Costas/0000-0001-7215-3610; Cuevas, Emilio/0000-0003-1843-8302; Nakane, Hideaki/0000-0002-9032-6105; Harris, Neil/0000-0003-1256-3006 NR 17 TC 53 Z9 54 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 16 PY 2001 VL 106 IS D7 BP 7495 EP 7503 DI 10.1029/2000JD900653 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 423QZ UT WOS:000168189400022 ER PT J AU Dvortsov, VL Solomon, S AF Dvortsov, VL Solomon, S TI Response of the stratospheric temperatures and ozone to past and future increases in stratospheric humidity SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-VAPOR; MIDDLE ATMOSPHERE; NUMERICAL-MODEL; METHANE PHOTOOXIDATION; TRENDS; CONTRAST AB Balloonsonde and aircraft in situ and remote sensing measurements in the Northern Hemisphere midlatitudes show that stratospheric humidity has been increasing since 1954. Satellite data, albeit only available over a much shorter period (1992 through 1999), also suggest that water Vapor has been increasing globally over much of the stratosphere. Implications of these trends for stratospheric temperatures and ozone are explored using a two-dimensional interactive radiative-chemical-dynamical model. It is shown that the increase in humidity cools the model stratosphere, in agreement with previous studies. Tn the midlatitude lower stratosphere, increasing water vapor induces a temperature trend of about -0.25 to -0.35 K per decade, which is similar to 30-50% of the observed cooling in this region. According to our results, such trends in water vapor have intensified Northern Hemisphere midlatitude ozone trends over the last few decades, mainly via the enhancement of ozone loss in HOx catalytic cycles and changes in chlorine partitioning tin spite of some buffering by concomitant increases in the O-3 production in the methane oxidation cycle). Increasing humidity in the model accounts for additional depletion of midlatitude column ozone at a rate of -0.3% per decade and up to -0.7% (-1%) per decade enhancement of local ozone trends in the lower (upper) stratospheres, accordingly. It is important to investigate what will be the likely consequences for stratospheric climate and ozone if the water Vapor trend continues. Our simulations suggest that smaller effects on ozone are to be expected over the 2000-2050 period as compared to 1979-1996 because of the projected reduction in the stratospheric chlorine land bromine) loading. However, our model simulations assuming World Meteorological Organization future emission scenarios for halogenated compounds, CH4, N2O, and CO2, show that increasing humidity will induce further cooling of the stratosphere and result in about a decade of delay in the ozone recovery, all other factors being equal. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Dvortsov, VL (reprint author), NOAA, Aeron Lab, 325 Broadway,R-AL8, Boulder, CO 80303 USA. NR 18 TC 65 Z9 66 U1 1 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 16 PY 2001 VL 106 IS D7 BP 7505 EP 7514 DI 10.1029/2000JD900637 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 423QZ UT WOS:000168189400023 ER PT J AU Harris, KD Vick, D Gonzalez, EJ Smy, T Robbie, K Brett, MJ AF Harris, KD Vick, D Gonzalez, EJ Smy, T Robbie, K Brett, MJ TI Porous thin films for thermal barrier coatings SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE growth models; electron beam evaporation; zirconium oxide; thermal barrier coatings ID GLANCING ANGLE DEPOSITION; MICROSTRUCTURES; CONDUCTIVITY AB A new approach is described in the deposition of thin films for thermal barrier applications. Using controlled substrate motion, porous layers and capping layers were vacuum deposited in an alternating fashion, creating a new, multilayered film structure. Direct measurements of the thermal properties of these multilayers were made using the 3 omega and Mirage techniques. In the 3 omega technique, heat is introduced into the coating by an AC current flowing through an evaporated resistor with a frequency omega. A fit of resistor voltage as a function of frequency yields the thermal conductivity. In the Mirage technique, an oscillating temperature is induced immediately above the film using a pulsed laser. A second probe laser aligned parallel to the surface is deflected by these temperature variations, and the thermal diffusivity is then found by fitting amplitude and phase shift data to the solution of the three-dimensional diffusion equation. Typically, the 3w and Mirage techniques measure thermal constants in directions normal and parallel to the substrate, respectively. Measurements using these methods led to estimates of a reduction in thermal diffusivity of as little as 9% of that of films deposited entirely at normal incidence. Thermal simulations of similar structures also predicted a substantial decrease in overall thermal conductivity. In a specific case, an improved conductivity of 18% of that of films deposited by standard techniques was estimated. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Alberta, Dept Elect & Comp Engn, Edmonton, AB T6G 2M7, Canada. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Carleton Univ, Dept Elect, Ottawa, ON K1S 5B6, Canada. Queens Univ, Dept Phys, Kingston, ON K7L 3N6, Canada. RP Harris, KD (reprint author), Univ Alberta, Dept Elect & Comp Engn, Edmonton, AB T6G 2M7, Canada. RI Harris, Ken/I-7219-2012 NR 27 TC 52 Z9 57 U1 1 U2 11 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD APR 16 PY 2001 VL 138 IS 2-3 BP 185 EP 191 DI 10.1016/S0257-8972(00)01155-5 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 410QG UT WOS:000167450200009 ER PT J AU Wegmann, J Albert, K Pursch, M Sander, LC AF Wegmann, J Albert, K Pursch, M Sander, LC TI Poly(ethylene-co-acrylic acid) stationary phases for the separation of shape constrained isomers SO ANALYTICAL CHEMISTRY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; POLYCYCLIC AROMATIC-HYDROCARBONS; STATE NMR-SPECTROSCOPY; RETENTION MECHANISMS; CAROTENOID ISOMERS; BONDING DENSITY; BONDED PHASES; CHAIN ORDER; SELECTIVITY; SILICA AB A new approach for the synthesis of long alkyl chain length stationary phases for use in reversed-phase liquid chromatography is described. Poly(ethylene-co-acrylic acid) copolymers (i.e., (-CH2CH2-)(x)[CH2CH(CO2H)-](y)) with different levels of acrylic acid were covalently bonded to silica via glycidoxypropyl or aminopropyl linkages. C-13 cross polarization magic angle spinning (CP/MAS) nuclear magnetic resonance (NMR) spectroscopy was used to characterize the new reversed-phase materials. Aspects of shape selectivity were evaluated for six different columns with Standard Reference Material (SRM) 869a, Column Selectivity Test Mixture for liquid Chromatography, Selectivity for isomer separations was enhanced for stationary phases prepared with poly(ethylene-co-acrylic acid) containing a mass fraction of 5% acrylic acid. The relationship between alkyl conformation and chromatographic properties was studied by C-13 magic angle spinning (MAS) NMR measurements, and correlations were made with the composition of the polymer. Finally, the effectiveness of this phase is demonstrated by the separation of several beta -carotene isomers. C1 Univ Tubingen, Inst Organ Chem, D-72076 Tubingen, Germany. NIST, Gaithersburg, MD 20899 USA. RP Wegmann, J (reprint author), Univ Tubingen, Inst Organ Chem, Morgenstelle 18, D-72076 Tubingen, Germany. NR 44 TC 28 Z9 28 U1 0 U2 8 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 APR 15 PY 2001 VL 73 IS 8 BP 1814 EP 1820 DI 10.1021/ac000992r PG 7 WC Chemistry, Analytical SC Chemistry GA 423BY UT WOS:000168156600022 PM 11338596 ER PT J AU Jander, A Moreland, J Kabos, P AF Jander, A Moreland, J Kabos, P TI Angular momentum and energy transferred through ferromagnetic resonance SO APPLIED PHYSICS LETTERS LA English DT Article ID TORQUE MAGNETOMETRY; MAGNETIC-FILMS; SPECTROSCOPY AB We show that ferromagnetic resonance (FMR) selectively transfers angular momentum and energy from a microwave held to the lattice as measurable torque and heat. The expected torque and absorbed power are derived classically in terms of Landau-Lifshitz dynamics, including demagnetizing field effects. The torque is also described as a photon absorption process, in which the absorbed photons carry both energy and angular momentum. FMR data are shown for a thin NiFe him deposited on a micromechanical cantilever detector that measures both torque and heat under nearly identical conditions. C1 Natl Inst Stand & Technol, Div Electromagnet Technol, Boulder, CO 80303 USA. RP Jander, A (reprint author), Natl Inst Stand & Technol, Div Electromagnet Technol, Boulder, CO 80303 USA. NR 17 TC 14 Z9 14 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 15 PY 2001 VL 78 IS 16 BP 2348 EP 2350 DI 10.1063/1.1361095 PG 3 WC Physics, Applied SC Physics GA 425EK UT WOS:000168275200028 ER PT J AU Marks, KM Tikku, AA AF Marks, KM Tikku, AA TI Cretaceous reconstructions of East Antarctica, Africa and Madagascar SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Indian Ocean; Cretaceous; Mozambique Basin; Riiser-Larsen Basin; gravity anomalies; plate tectonics; reconstruction ID MOZAMBIQUE BASIN; FRACTURE-ZONE; GRAVITY-FIELD; SOMALI BASIN; INDIAN-OCEAN; RIDGE; ANOMALIES; HISTORY AB Some Cretaceous reconstructions of East Antarctica, Africa, and Madagascar overlap the Mozambique ridge onto the margin of Dronning Maud Land, and others place Madagascar west of the Gunnerus ridge, into the Riiser-Larsen Sea. Our M10Ny (131.9 Ma), MO (120.4 Ma), 96 Ma, and 34y (83 Ma) marine free-air gravity and topography reconstructions illustrate a solution to the overlap problem and also demonstrate that Madagascar separated from Antarctica east of the Gunnerus ridge. Our reconstructions chronicle the growth of the conjugate Mozambique and Riiser-Larsen Basins created at the Southwest Indian spreading ridge. Well defined spreading corridors, identified by conjugate fracture zones and Mesozoic magnetic anomaly identifications, extend from one basin into the other. We find that the eastern scarp of the Mozambique ridge aligns with the Astrid ridge, and there is no room for Madagascar west of the Gunnerus ridge. The overlap of the Mozambique ridge is solved by taking into account the motion of an independent Mozambique ridge microplate that existed from Chron M11 to circa M2. Published by Elsevier Science B.V. C1 NOAA, Lab Satellite Alimetry, Silver Spring, MD 20910 USA. RP Marks, KM (reprint author), NOAA, Lab Satellite Alimetry, E-RA31,1315 East West Hwy, Silver Spring, MD 20910 USA. RI Marks, Karen/F-5610-2010 OI Marks, Karen/0000-0001-6524-1495 NR 36 TC 59 Z9 65 U1 2 U2 11 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 APR 15 PY 2001 VL 186 IS 3-4 BP 479 EP 495 DI 10.1016/S0012-821X(01)00262-X PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 425YD UT WOS:000168318500012 ER PT J AU Rodionov, S Assel, R AF Rodionov, S Assel, R TI A new look at the Pacific/North American index SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID UNITED-STATES CLIMATE; TELECONNECTION PATTERN; CIRCULATION PATTERNS; VARIABILITY; ENSO; WINTER; OSCILLATION AB This study examines inconsistencies in the Pacific/North American (PNA) index relative to atmospheric circulation over North America. Two types of atmospheric circulation were found to be associated with high PNA values. The first type is the true PNA pattern characterized by an amplified ridge-trough system. It appears to be related to the leading mode of sea surface temperature variability in the North Pacific. The second type is observed during El Nino events. It is characterized by a flattening of the polar jet stream and southward shift of the subtropical jet stream. The recognition of these two types of the PNA index improves our understanding of the relative role of to El Nino/Southern Oscillation events and sea surface temperatures in the North Pacific in affecting winter atmospheric circulation over North America. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Rodionov, S (reprint author), Univ Colorado, Dept Comp Sci, Campus Box 430, Boulder, CO 80309 USA. OI Rodionov, Sergei/0000-0002-5318-9746 NR 18 TC 21 Z9 21 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 15 PY 2001 VL 28 IS 8 BP 1519 EP 1522 DI 10.1029/2000GL012185 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 421LP UT WOS:000168066100029 ER PT J AU Wetherald, RT Stouffer, RJ Dixon, KW AF Wetherald, RT Stouffer, RJ Dixon, KW TI Committed warming and its implications for climate change SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OCEAN-ATMOSPHERE MODEL; CARBON-DIOXIDE; TRANSIENT RESPONSES; GRADUAL CHANGES; SUMMER DRYNESS; SENSITIVITY; CO2; INCREASE; TEMPERATURE AB Time lags between changes in radiative forcing and the resulting simulated climate responses are investigated in a set of transient climate change experiments. Both surface air temperature (SAT) and soil moisture responses are examined. Results suggest that if the radiative forcing is held fixed at today's levels, the global mean SAT will rise an additional 1.0K before equilibrating. This unrealized warming commitment is larger than the 0.6K warming observed since 1900. The coupled atmosphere-ocean GCM's transient SAT response for the year 2000 is estimated to be similar to its equilibration response to 1980 radiative forcings - a lag of similar to 20 years. Both the time lag and the warming commitment are projected to increase in the future, and depend on the model's climate sensitivity, oceanic heat uptake, and the forcing scenario. These results imply that much of the warming due to current greenhouse gas levels is yet to be realized. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Wetherald, RT (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. RI Dixon, Keith/L-7120-2015 OI Dixon, Keith/0000-0003-3044-326X NR 26 TC 39 Z9 40 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 15 PY 2001 VL 28 IS 8 BP 1535 EP 1538 DI 10.1029/2000GL011786 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 421LP UT WOS:000168066100033 ER PT J AU Hewitt, CD Broccoli, AJ Mitchell, JFB Stouffer, RJ AF Hewitt, CD Broccoli, AJ Mitchell, JFB Stouffer, RJ TI A coupled model study of the last glacial maximum: Was part of the North Atlantic relatively warm? SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLIMATE MODEL; CIRCULATION; SEA; TEMPERATURE; SENSITIVITY; SIMULATION AB A coupled ocean-atmosphere general circulation model is used to simulate the climates of today and the last glacial maximum (LGM). The model, which does not require artificial flux adjustments, produces a pattern of cooling at the LGM that is broadly consistent with the findings from simpler models and palaeoclimatic data. However, changes to the ocean circulation produce anomalously warm LGM surface conditions over parts of the North Atlantic, seemingly at odds with palaeoceanographic data. The thermohaline circulation is intensified for several centuries, as is the northward heat transport in the Atlantic equatorward of 55 degreesN, but this may be a transient result. Mechanisms that lead to this response are discussed. C1 Hadley Ctr, Met Off, Bracknell RG12 2SY, Berks, England. Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Hewitt, CD (reprint author), Hadley Ctr, Met Off, London Rd, Bracknell RG12 2SY, Berks, England. RI Broccoli, Anthony/D-9186-2014 OI Broccoli, Anthony/0000-0003-2619-1434 NR 24 TC 82 Z9 84 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 15 PY 2001 VL 28 IS 8 BP 1571 EP 1574 DI 10.1029/2000GL012575 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 421LP UT WOS:000168066100042 ER PT J AU Zhang, JZ Wanninkhof, R Lee, K AF Zhang, JZ Wanninkhof, R Lee, K TI Enhanced new production observed from the diurnal cycle of nitrate in an oligotrophic anticyclonic eddy SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GAS-EXCHANGE; SARGASSO SEA; OPEN-OCEAN; INCREASE; NITROGEN; PACIFIC; EDDIES; TRACER; LAYER; RATES AB A diurnal study in an anticyclonic eddy provides the first evidence of nutrient dynamics consistent with the observed trends in solar radiation, oxygen concentration changes, and estimates of the eddy diffusive flux of nitrate from nitracline. A new production rate of 24 mmol C m(-2) d(-1) was determined from nitrate inventory changes at nM levels in the mixed layer using a liquid waveguide technique combined with eddy diffusion estimates across the base of the mixed layer from temporal changes in the vertical penetration of SF,. The new production supported by nitrate from deepening of the mixed layer after storm events is two times larger than that from the daily diffusive flux. Our results demonstrate that new production in the oligotrophic ocean can be enhanced by a supply of nitrate through the eddy turbulence-induced diffusive flux and entrainment during storms. C1 Univ Miami, Cooperat Inst Marine & Atmospher Sci, Miami, FL 33149 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Div, Miami, FL 33149 USA. RP Zhang, JZ (reprint author), Univ Miami, Cooperat Inst Marine & Atmospher Sci, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. RI Zhang, Jia-Zhong/B-7708-2008; Lee, Kitack/G-7184-2015 OI Zhang, Jia-Zhong/0000-0002-1138-2556; NR 30 TC 32 Z9 33 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 15 PY 2001 VL 28 IS 8 BP 1579 EP 1582 DI 10.1029/2000GL012065 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 421LP UT WOS:000168066100044 ER PT J AU Seki, MP Polovina, JJ Brainard, RE Bidigare, RR Leonard, CL Foley, DG AF Seki, MP Polovina, JJ Brainard, RE Bidigare, RR Leonard, CL Foley, DG TI Biological enhancement at cyclonic eddies tracked with GOES thermal imagery in Hawaiian waters SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MESOSCALE EDDY; UPPER OCEAN; PACIFIC; SEA AB In November 1999, ship and satellite platforms were used to track, target and map the vertical and horizontal structure of two cyclonic eddies in the lee of Hawaii. Depth-integrated nitrate+nitrite levels within the photic zone of the eddy cores were 3- to 15- fold higher than those observed for control stations. The depth and magnitude of the deep chlorophyll maximum were significantly elevated in the more mature of the two eddies. HPLC analyses revealed that the enhanced chlorophyll was largely contributed by chromophyte microalgae. Modeled primary productivity rates were up to twofold higher at the stations within the eddies. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Univ Hawaii, Dept Oceanog, SOEST, Honolulu, HI 96822 USA. Univ Hawaii, Joint Inst Marine & Atmospher Res, SOEST, Honolulu, HI 96822 USA. RP Seki, MP (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. NR 14 TC 87 Z9 91 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 15 PY 2001 VL 28 IS 8 BP 1583 EP 1586 DI 10.1029/2000GL012439 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 421LP UT WOS:000168066100045 ER PT J AU Wang, CZ Enfield, DB AF Wang, CZ Enfield, DB TI The tropical Western Hemisphere warm pool SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EL-NINO; OCEAN AB The Western Hemisphere warm pool (WHWP) of water warmer than 28.5 degreesC extends from the eastern North Pacific to the Gulf of Mexico and the Caribbean, and at its peak, overlaps with the tropical North Atlantic. It has a large seasonal cycle and its interannual fluctuations of area and intensity are significant. Surface heat fluxes warm the WHWP through the boreal spring to an annual maximum of SST and areal extent in the late summer/early fall, associated with eastern North Pacific and Atlantic hurricane activities and rainfall from northern South America to the southern tier of the United States. SST and area anomalies occur at high temperatures where small changes can have a large impact on tropical convection. Observations suggest that a positive ocean-atmosphere feedback operating through longwave radiation and associated cloudiness is responsible for the WHWP SST anomalies. Associated with an increase in SST anomalies is a decrease in atmospheric sea level pressure anomalies and an anomalous increase in atmospheric convection and cloudiness. The increase in convective activity and cloudiness results in less longwave radiation loss from the surface, which then reinforces SST anomalies. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Phys Oceanog Div, Miami, FL 33149 USA. RP Wang, CZ (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Phys Oceanog Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Wang, Chunzai /C-9712-2009; Enfield, David/I-2112-2013 OI Wang, Chunzai /0000-0002-7611-0308; Enfield, David/0000-0001-8107-5079 NR 16 TC 156 Z9 167 U1 1 U2 15 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 APR 15 PY 2001 VL 28 IS 8 BP 1635 EP 1638 DI 10.1029/2000GL011763 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 421LP UT WOS:000168066100058 ER PT J AU Taylor, PJ Jesser, WA Benson, JD Martinka, M Dinan, JH Bradshaw, J Lara-Taysing, M Leavitt, RP Simonis, G Chang, W Clark, WW Bertness, KA AF Taylor, PJ Jesser, WA Benson, JD Martinka, M Dinan, JH Bradshaw, J Lara-Taysing, M Leavitt, RP Simonis, G Chang, W Clark, WW Bertness, KA TI Optoelectronic device performance on reduced threading dislocation density GaAs/Si SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; SI; GROWTH; SILICON; SUBSTRATE; INTEGRATION; NUCLEATION; QUALITY; SURFACE; ISSUES AB A technique for the heteroepitaxy of GaAs/Si films having reduced threading dislocation density is presented. The important attribute of this technique is the suppression of three-dimensional Volmer-Weber island formation during initial deposition. This suppression is achieved by deposition of a stoichiometric GaAs buffer layer by a migration-enhanced epitaxy technique on silicon at 348 K to a thickness greater than the "monolithic thickness," h(m). Subsequent GaAs films deposited by conventional molecular beam epitaxy on buffer layers of thickness greater than h(m) possess structural and optical characteristics that exceed those for state-of-the-art GaAs/Si layers: an x-ray full width at half maximum (FWHM) of 110 arcsec with a dislocation density at the film surface of 3x10(6) cm(-2) and a concomitant 4 K photoluminescence FWHM of 2.1 meV. The p-i-n structures suitable for use as light-emitting diodes (LEDs) that were grown on the reduced threading dislocation density GaAs/Si and by means of forward- and reverse-bias measurements, demonstrated an ideality factor of n=1.5, an increased reverse-bias breakdown electric field of 2.1x10(7) V/m, and an intrinsic region resistivity of 4x10(7) Omega cm for LEDs of increasingly smaller mesa size. (C) 2001 American Institute of Physics. C1 Univ Virginia, Dept Mat Sci & Engn, Charlottesville, VA 22903 USA. USA, CECOM, Night Vis & Elect Sensors Directorate, Ft Belvoir, VA 22060 USA. USA, Res Lab, Electroopt & Photon Div, Adelphi, MD 20783 USA. Natl Inst Stand & Technol, Optoelect Div 815, Boulder, CO 80305 USA. RP Taylor, PJ (reprint author), MIT, Lincoln Lab, 244 Wood St, Lexington, MA 02420 USA. RI Bradshaw, John/E-8330-2011 NR 42 TC 28 Z9 30 U1 2 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 2001 VL 89 IS 8 BP 4365 EP 4375 DI 10.1063/1.1347000 PG 11 WC Physics, Applied SC Physics GA 417HB UT WOS:000167828500023 ER PT J AU Anthony, EB Bierbaum, VM Leone, SR AF Anthony, EB Bierbaum, VM Leone, SR TI Rotational-state and velocity-subgroup dependence of the rotational alignment of N-2(+) drifted in He SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ANGULAR-MOMENTUM POLARIZATION; SUPERSONIC SEEDED BEAMS; COLLISIONAL ALIGNMENT; MOLECULAR-BEAMS; EXPANSION; DYNAMICS; OXYGEN; HELIUM; CO2 AB Experimental results are presented for the rotational alignment of N-2(+)(v(')=0) as a function of both rotational state and component Doppler velocity. A single-frequency ring dye laser is used to probe the alignment of N-2(+) drifted in helium in a flow-drift apparatus by the technique of polarized laser-induced fluorescence. The collision-induced quadrupole rotational alignment parameter A(0)((2)) is determined as a function of the field direction component of sub-Doppler laboratory velocity at a fixed field strength of 12 Td for five rotational states. A dramatic difference in velocity-selected alignment as a function of rotational state is observed, with the higher rotational states exhibiting a greater degree of alignment than the lower rotational states. Additionally, for sufficiently low rotational state (J=11.5), A(0)((2)) changes sign across the Doppler profile, a behavior that has not previously been reported in the literature. A companion theoretical paper presents molecular dynamics calculations that are in excellent agreement with these experimental observations. (C) 2001 American Institute of Physics. C1 JILA, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Div Quantum Phys, Boulder, CO USA. RP Anthony, EB (reprint author), Meadowlark Opt, 5964 Iris Pkwy, Frederick, CO 80530 USA. NR 24 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 15 PY 2001 VL 114 IS 15 BP 6654 EP 6661 DI 10.1063/1.1354176 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 418VG UT WOS:000167914400019 ER PT J AU Li, XF Zheng, QN Pichel, WG Yan, XH Liu, WT Clemente-Colon, P AF Li, XF Zheng, QN Pichel, WG Yan, XH Liu, WT Clemente-Colon, P TI Analysis of coastal lee waves along the coast of Texas observed in advanced very high resolution radiometer images SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ATMOSPHERE AB We examine a group of wave-like cloud patterns that occurred along the coast of Texas on a National Oceanic and Atmospheric Administration satellite advanced very high resolution radiometer IR images taken on January 22, 1999. These wave-like cloud patterns were interpreted to be signatures of a coastal lee wave packet on the basis of simultaneous field observations and theories developed by Zheng et al. [1998a]. The wave packet contains 13 waves with crest lines generally parallel to the coastline. The lengths of leading wave crest lines are longer than 500 km. The average wavelength is 9.5 km, ranging from 6.2 to 14.7 km. The width of the horizontal distribution band of the wave packet is as wide as 113 km. This case represents the most energetic coastal lee wave packet that has ever been reported. C1 NOAA, NESDIS, Camp Springs, MD 20746 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Delaware, Coll Marine Studies, Newark, DE 19716 USA. RP Li, XF (reprint author), NOAA, NESDIS, E-RA3,Room 102,WWBG,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Clemente-Colon, Pablo/F-5581-2010; Zheng, Quanan/F-9025-2010; Pichel, William/F-5619-2010; Li, Xiaofeng/B-6524-2008 OI Pichel, William/0000-0001-6332-0149; Li, Xiaofeng/0000-0001-7038-5119 NR 13 TC 16 Z9 16 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 APR 15 PY 2001 VL 106 IS C4 BP 7017 EP 7025 DI 10.1029/1999JC000019 PG 9 WC Oceanography SC Oceanography GA 422UJ UT WOS:000168137400013 ER PT J AU Daly, KL Smith, WO Johnson, GC DiTullio, GR Jones, DR Mordy, CW Feely, RA Hansell, DA Zhang, JZ AF Daly, KL Smith, WO Johnson, GC DiTullio, GR Jones, DR Mordy, CW Feely, RA Hansell, DA Zhang, JZ TI Hydrography, nutrients, and carbon pools in the Pacific sector of the Southern Ocean: Implications for carbon flux SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ANTARCTIC CIRCUMPOLAR CURRENT; ZONE COLOR SCANNER; INTERMEDIATE WATER; NEW-ZEALAND; PHYTOPLANKTON BLOOMS; ORGANIC-CARBON; SUBTROPICAL CONVERGENCE; ECOSYSTEM STRUCTURE; SURFACE WATERS; INDIAN SECTOR AB We investigated the hydrography, nutrients, and dissolved and particulate carbon pools in the western Pacific sector of the Antarctic Circumpolar Current (ACC) during austral summer 1996 to assess the region's role in the carbon cycle. Low fCO(2) values along two transects indicated that much of the study area was a sink for atmospheric CO2. The fCO(2) values were lowest near the Polar Front (PF) and the Subtropical Front (STF), concomitant with maxima of chlorophyll a and particulate and dissolved organic carbon. The largest biomass accumulations did not occur at fronts, which had high surface geostrophic velocities (20-51 cm s(-1)), but in relatively low velocity regions near fronts or in an eddy. Thus vertical motion and horizontal advection associated with fronts may have replenished nutrients in surface waters but also dispersed phytoplankton. Although surface waters north of the PF have been characterized as a "high nutrient-low chlorophyll" region, low silicic acid (Si) concentrations (2-4 muM) may limit production of large diatoms and therefore the potential carbon flux. Low concentrations (4-10 muM Si) at depths of winter mixing constrain the level of Si replenishment to surface waters. It has been suggested that an increase in aeolian iron north of the PF may increase primary productivity and carbon export. Our results, however, indicate that while diatom growth and carbon export may be enhanced, the extent ultimately would be limited by the vertical supply of Si. South of the PF, the primary mechanism by which carbon is exported to deep water appears to be through diatom flux. We suggest that north of the PF, particulate and dissolved carbon may be exported primarily to intermediate depths through subduction and diapycnal mixing associated with Subantarctic Mode Water and Antarctic Intermediate Water formation. These physical-biological interactions and Si dynamics should be included in future biogeochemical models to provide a more accurate prediction of carbon flux. C1 Coll William & Mary, Virginia Inst Marine Sci, Gloucester Point, VA USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Charleston, Grice Marine Lab, Charleston, SC 29412 USA. Univ Washington, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98195 USA. Bermuda Biol Stn Res, St Georges, Bermuda. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Cooperat Inst Marine & Atmospher Studies, Miami, FL 33149 USA. Univ Tennessee, Dept Ecol & Evolutionary Biol, Knoxville, TN USA. RP Daly, KL (reprint author), Univ S Florida, Coll Marine Sci, 140 7th Ave S, St Petersburg, FL 33701 USA. RI Zhang, Jia-Zhong/B-7708-2008; Johnson, Gregory/I-6559-2012; OI Zhang, Jia-Zhong/0000-0002-1138-2556; Johnson, Gregory/0000-0002-8023-4020; Hansell, Dennis/0000-0001-9275-3445 NR 96 TC 22 Z9 22 U1 2 U2 12 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 APR 15 PY 2001 VL 106 IS C4 BP 7107 EP 7124 DI 10.1029/1999JC000090 PG 18 WC Oceanography SC Oceanography GA 422UJ UT WOS:000168137400020 ER PT J AU Jeon, HS Kim, S Han, CC AF Jeon, HS Kim, S Han, CC TI Phase separation induced by shear quenching in polymer blends with a diblock copolymer SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE phase separation; shear quench; block copolymer; PB; PS; blend; interfacial modification ID SPINODAL DECOMPOSITION; BLOCK-COPOLYMER; LIGHT-SCATTERING; INDUCED HOMOGENIZATION; POLYOLEFIN BLENDS; BINARY-MIXTURES; KINETICS; INTERFACES; TIME; FLOW AB The effects of adding A-B diblock copolymer to a polymer blend (A/B) on phase-separation kinetics and morphology have been investigated in a fixed shallow-quench condition (DeltaT = 1.5 degreesC) by in situ time-resolved light scattering and phase-contrast optical microscopy. A shear-quench technique was used in this study instead of a conventional temperature-quench method. Mixtures of nearly monodisperse low relative-molecular masses of polybutadiene (M(w) = 2.8 kg/mol), polystyrene (M(w) = 2.6 kg/mol), and a near-symmetric butadiene-styrene diblock copolymer (M(w) = 6.3 kg/mol) as an interfacial modifier were studied. We observed that the addition of the diblock copolymer could either retard or accelerate the phase-separation kinetics depending on the concentration of the diblock copolymer in the homopolymer blends. In contrast to the conventional temperature quench, we observed complex phase-separation kinetics in the intermediate and late stages of phase separation by the shear-quench technique. (C) 2001 John Wiley & Sons, Inc. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. New Mexico Inst Min & Technol, Dept Chem & Petr Engn, Socorro, NM 87801 USA. USDA ARS, Natl Ctr Agr Utilizat Res, Peoria, IL 61604 USA. RP Han, CC (reprint author), Natl Inst Stand & Technol, Div Polymers, A207-Bldg 224,Mail Stop 8544, Gaithersburg, MD 20899 USA. EM charles.han@nist.gov NR 30 TC 4 Z9 4 U1 1 U2 2 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD APR 15 PY 2001 VL 39 IS 8 BP 819 EP 830 DI 10.1002/polb.1056 PG 12 WC Polymer Science SC Polymer Science GA 412RP UT WOS:000167568400001 ER PT J AU Conzone, SD Hayden, JS Funk, DS Roshko, A Veasey, DL AF Conzone, SD Hayden, JS Funk, DS Roshko, A Veasey, DL TI Hybrid glass substrates for waveguide device manufacture SO OPTICS LETTERS LA English DT Article ID WAVE-GUIDE LASERS; PHOSPHATE-GLASS; ARRAYS AB Hybrid glass substrates were prepared by a novel, low-temperature process joining active (Er-Yb codoped) and passive phosphate glass. The resulting hybrid substrates are chemically and physically robust; they can be cut, ground, and polished by conventional, water-based techniques. The entire substrate can be immersed in a molten-salt bath to produce waveguides simultaneously in the active and passive regions. A low reflectance of -34 +/- 2 dB was measured at the joint interface with 1531.2-nm light by optical low-coherence reflectometry. Further, a hybrid laser waveguide device exhibited a slope efficiency of 33% at 1540 nm when pumped at 975 nm. C1 Schott Glass Technol, Duryea, PA 18642 USA. Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Conzone, SD (reprint author), Schott Glass Technol, 400 York Ave, Duryea, PA 18642 USA. NR 7 TC 27 Z9 27 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD APR 15 PY 2001 VL 26 IS 8 BP 509 EP 511 DI 10.1364/OL.26.000509 PG 3 WC Optics SC Optics GA 424FW UT WOS:000168222500012 PM 18040368 ER PT J AU Pratt, JR Nayfeh, AH AF Pratt, JR Nayfeh, AH TI Chatter control and stability analysis of a cantilever boring bar under regenerative cutting conditions SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE machine-tool chatter; vibration control; Hopf bifurcation; boring; nonlinear dynamics ID DYNAMICS; MODEL AB A theoretical and experimental investigation into the stability of a slender boring bar under regenerative cutting conditions is presented. The bar has been equipped with actuators and sensors for feedback control of its structural dynamics. It is modelled at the tool point by a mass-spring-damper system free to move in two mutually perpendicular directions. Our aim is to demonstrate the effect of simple feedback control on the parameter space of chatter-free machining in a boring process using theory and experiment. We reinforce the notion that the system design for control should provide actuation in two orthogonal directions because the cutting forces couple the principal modes of the tool in a complex fashion. Active control of the tool damping in each of the principal modal directions is implemented and shown in theory and experiment to be quite effective at suppressing chatter. Problems caused by jumps front stable to unstable cutting due to nonlinear regenerative chatter effects are also considered. The case where the cutting forces are described by polynomial functions of the chip thickness is examined. We use a perturbation technique to calculate the nonlinear normal form of the governing equations to determine the post-linear instability (bifurcation) behaviour. The predicted bifurcation corresponds to a subcritical Hopf bifurcation, and hence the predicted transition from stable to unstable cutting is not smooth and may possess hysteresis. This result is in qualitative agreement with experimental observations. An active control technique for changing the form of this bifurcation from subcritical to supercritical is presented for a prototypical, single-degree-of-freedom model. C1 Natl Inst Stand & Technol, Mfg Engn Lab, Gaithersburg, MD 20899 USA. Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. RP Pratt, JR (reprint author), Natl Inst Stand & Technol, Mfg Engn Lab, Gaithersburg, MD 20899 USA. NR 52 TC 52 Z9 52 U1 3 U2 15 PU ROYAL SOC LONDON PI LONDON PA 6 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T ROY SOC A JI Philos. Trans. R. Soc. Lond. Ser. A-Math. Phys. Eng. Sci. PD APR 15 PY 2001 VL 359 IS 1781 BP 759 EP 792 PG 34 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 424JH UT WOS:000168228800006 ER PT J AU Davies, MA Burns, TJ AF Davies, MA Burns, TJ TI Thermomechanical oscillations in material flow during high-speed machining SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE high-speed machining; Hopf bifurcation; relaxation oscillations; chaotic dynamics; plasticity; adiabatic shear bands ID SHEAR BAND; SIMULATION AB This paper presents a nonlinear dynamics approach for predicting the transition from continuous to shear-localized chip formation in machining. Experiments and a simplified one-dimensional model of the flow both show that, as cutting speed is increased, a transition takes place from continuous to shear-localized chip formation in the flowfield of the material being cut. Initially, the process appears to be somewhat disordered. With further increases in cutting speed! the average spacing between shear bands increases monotonically, and the spacing becomes more regular and asymptotically approaches a limiting value that is determined by the cutting conditions and the properties of the workpiece material. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Davies, MA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 58 TC 31 Z9 34 U1 1 U2 5 PU ROYAL SOC LONDON PI LONDON PA 6 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T ROY SOC A JI Philos. Trans. R. Soc. Lond. Ser. A-Math. Phys. Eng. Sci. PD APR 15 PY 2001 VL 359 IS 1781 BP 821 EP 846 PG 26 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 424JH UT WOS:000168228800008 ER PT J AU Takacs, E Berenyi, Z Gillaspy, JD Ratliff, LP Minniti, R Pedulla, J Deslattes, RD Stolterfoht, N AF Takacs, E Berenyi, Z Gillaspy, JD Ratliff, LP Minniti, R Pedulla, J Deslattes, RD Stolterfoht, N TI Separation of inner-shell vacancy transfer mechanisms in collisions of slow Ar17+ ions with SiO2 SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID HIGHLY-CHARGED IONS; X-RAY-EMISSION; HOLLOW ATOMS; SURFACE; SCATTERING; NEUTRALIZATION; EQUILIBRATION; BOMBARDMENT; EXCITATION; ELECTRONS AB We have studied the spectrum of x-rays emitted when 130 and 200 keV kinetic energy hydrogen-like argon ions impact silicon dioxide surfaces, Specifically, we were interested in the mechanism for creation of K-shell holes in the silicon target atoms, which can be filled with the release of a 1.75 keV x-ray. Two mechanisms have been hypothesized for the vacancy transfer between the K-shells of silicon and argon atoms: 'direct vacancy transfer' and 'projectile-decay-product-mediated vacancy transfer'. To separate these mechanisms, we used a target with a metallic coating (preventing close collisions between Si and Ar but allowing x-ray transmission) and a target without such a coating. We found that x-ray photoionization is the dominant mechanism in both cases and measured an upper limit for the contribution from the 'direct mechanism' on the uncoated sample, Furthermore, we measured the relative strengths of the K alpha, K beta and K gamma lines of the argon projectile as a function of kinetic energy and found satisfactory agreement with charge exchange and cascade model calculations. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Debrecen, Inst Phys Expt, ATOMKI, H-4026 Debrecen, Hungary. Hahn Meitner Inst Berlin GmbH, D-14109 Berlin, Germany. RP Takacs, E (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 41 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 EI 1361-6455 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD APR 14 PY 2001 VL 34 IS 7 BP 1277 EP 1287 DI 10.1088/0953-4075/34/7/310 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 428JE UT WOS:000168457900015 ER PT J AU Levitus, S Antonov, JI Wang, JL Delworth, TL Dixon, KW Broccoli, AJ AF Levitus, S Antonov, JI Wang, JL Delworth, TL Dixon, KW Broccoli, AJ TI Anthropogenic warming of Earth's climate system SO SCIENCE LA English DT Article ID OCEAN-ATMOSPHERE MODEL; 20TH-CENTURY TEMPERATURE AB We compared the temporal variability of the heat content of the world ocean, of the global atmosphere, and of components of Earth's cryosphere during the Latter half of the 20th century. Each component has increased its heat content (the atmosphere and the ocean) or exhibited melting (the cryosphere). The estimated increase of observed global ocean heat content lover the depth range from 0 to 3000 meters) between the 1950s and 1990s is at least one order of magnitude Larger than the increase in heat content of any other component. Simulation results using an atmosphere-ocean general circulation model that includes estimates of the radiative effects of observed temporal variations in greenhouse gases, sulfate aerosols, solar irradiance, and volcanic aerosols over the past century agree with our observation-based estimate of the increase in ocean heal content. The results we present suggest that the observed increase in ocean heat content may largely be due to the increase of anthropogenic gases in Earth's atmosphere. C1 NOAA, NODC, Air Resources Lab, EOC5, Silver Spring, MD 20910 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Levitus, S (reprint author), NOAA, NODC, Air Resources Lab, EOC5, 1315 East West Highway, Silver Spring, MD 20910 USA. RI Delworth, Thomas/C-5191-2014; Broccoli, Anthony/D-9186-2014; Dixon, Keith/L-7120-2015; Wang, Julian/C-3188-2016 OI Broccoli, Anthony/0000-0003-2619-1434; Dixon, Keith/0000-0003-3044-326X; NR 25 TC 308 Z9 328 U1 7 U2 68 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 APR 13 PY 2001 VL 292 IS 5515 BP 267 EP 270 DI 10.1126/science.1058154 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 421QA UT WOS:000168074000041 PM 11303098 ER PT J AU Briggman, KA Stephenson, JC Wallace, WE Richter, LJ AF Briggman, KA Stephenson, JC Wallace, WE Richter, LJ TI Absolute molecular orientational distribution of the polystyrene surface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID FREQUENCY VIBRATIONAL SPECTROSCOPY; POTENTIAL SURFACE; POLYMER SURFACE; THIN-FILMS; BENZENE; GENERATION; INTERFACE; INTENSITIES; TEMPERATURE; SIMULATION AB Vibrationally resonant sum frequency generation (VR-SFG) has been used to study the absolute molecular orientational distribution of the pendant phenyl groups at the foe surface of polystyrene (PS) thin films on oxidized Si substrates. Characterization of the dependence of the VR-SFG on film thickness allows unique identification of the origin of the signal, e.g., free surface, bulk, or buried interface. For films <400 nm thick, the dominant source of vibrationally resonant signal is the PS/air interface, while the dominant source of the nonresonant background is the Si/SiO2 interface. VR-SFG of a self-assembled phenylsiloxane layer is used to calibrate the relative phase between the vibrationally resonant phenyl ring hyperpolarizability and the Si/SiO2 interface nonresonant hyperpolarizability. It is found that the phenyl groups are ordered at the PS/air interface and are oriented away from the polymer film. Quantitative analyses of the orientational distribution for both the PS free interface and the phenylsiloxane monolayer are reported. The phenyl groups at the PS free surface are tilted away from the surface normal in an angular range near 57. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Richter, LJ (reprint author), Natl Inst Stand & Technol, 100 Bur Dr, Gaithersburg, MD 20899 USA. RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 44 TC 157 Z9 158 U1 1 U2 33 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 APR 12 PY 2001 VL 105 IS 14 BP 2785 EP 2791 DI 10.1021/jp0037495 PG 7 WC Chemistry, Physical SC Chemistry GA 423LQ UT WOS:000168178100018 ER PT J AU Molloy, DP Giamberini, L Morado, JF Fokin, SI Laruelle, F AF Molloy, DP Giamberini, L Morado, JF Fokin, SI Laruelle, F TI Characterization of intracytoplasmic prokaryote infections in Dreissena sp (Bivalvia : Dreissenidae) SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE zebra mussels; intracytoplasmic prokaryote; epithelium; connective tissue; virus-like particles; Rickettsiales-like; Chlamydiales-like ID RICKETTSIALES-LIKE INFECTION; OYSTER CRASSOSTREA-GIGAS; CHLAMYDIA-LIKE ORGANISMS; SCALLOP PECTEN-MAXIMUS; GILL EPITHELIAL-CELLS; HARD CLAMS MERCENARIA; POTOMAC HORSE FEVER; PACIFIC RAZOR CLAM; DIGESTIVE GLAND; NORTH-AMERICA AB This study characterizes intracytoplasmic infections with prokaryote microorganisms in Dreissena sp. (near Dreissena polymorpha) from northeastern Greece and represents the first report of such infections in freshwater bivalves. Light microscope observations of stained tissues revealed basophilic, cytoplasmic inclusion bodies in 87.5% (28/32) of the mussels sectioned. Inclusions in epithelial cells and connective tissues were noted, respectively, in 34.4 and 71.9% of the sample, with 5 mussels (15.6%) having both tissue types infected. Epithelial cell infections were observed in histological sections only in digestive gland tubules and ducts; within tubules, inclusions were present more often in secretory than digestive cells. Connective tissue infections, however, were systemic; among the 32 mussels sectioned, inclusions were found in the gills (65.6%), foot (12.5%), mantle (9.4%), labial palps (6.3%), digestive gland (6.3%), stomach (6.3%), and gonads (3.1%). Cytoplasmic inclusions (maximum dimension, 138 mum) were prominent enough in the gills to be visible in 17.0% of the 247 mussels dissected. Ultrastructurally, prokaryote cells in gill connective tissues were clearly characteristic of Chlamydiales-like organisms, with each intracytoplasmic inclusion containing a loosely packed mixture of elementary, reticulate, intermediate bodies, and blebs. Prokaryote colonies in digestive gland epithelial cells exclusively contained 1 of 4 morphological cell types and were considered Rickettsiales-like. Hexagonal, virus-like particles were present in the cytoplasm of the largest of these Rickettsiales-like prokaryotes. Although host stress was evident from localized cell necrosis and dense hemocyte infiltration, overall infection was fairly benign, with no major, adverse impact on body condition evident among sectioned or dissected mussels. A possible negative effect was partial constriction of gill water tubes, but at the infection intensity observed (typical range 1 to 7 inclusion bodies per section), significant interference with respiration and other metabolic functions of the gills was highly unlikely. C1 New York State Museum, State Educ Dept, Cultural Educ Ctr, Albany, NY 12230 USA. Univ Metz, Equipe Prod Ecosyst & Ecotoxicol, Lab EBSE, F-57070 Metz, France. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Resource Assessment & Conservat Engn Div, Seattle, WA 98115 USA. St Petersburg State Univ, Biol Res Inst, St Petersburg 198904, Russia. European Univ Inst, CNRS, UMR 6539, UBO, F-29280 Plouzane, France. RP Molloy, DP (reprint author), New York State Museum, State Educ Dept, Cultural Educ Ctr, Albany, NY 12230 USA. OI FOKIN, SERGEY/0000-0002-8359-2819 NR 59 TC 20 Z9 21 U1 2 U2 6 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0177-5103 J9 DIS AQUAT ORGAN JI Dis. Aquat. Org. PD APR 10 PY 2001 VL 44 IS 3 BP 203 EP 216 DI 10.3354/dao044203 PG 14 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA 434EU UT WOS:000168802800006 PM 11383568 ER PT J AU Morgan, AB Gilman, JW Jackson, CL AF Morgan, AB Gilman, JW Jackson, CL TI Characterization of the dispersion of clay in a polyetherimide nanocomposite SO MACROMOLECULES LA English DT Article ID POLYMER; POLYIMIDE; HYBRID; INTERCALATION; SILICATES C1 Natl Inst Stand & Technol, Fire Sci Div, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymer, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Morgan, AB (reprint author), Dow Chem Co, Corp R&D, Nanomat Grp, Midland, MI 48674 USA. RI Morgan, Alexander/A-9672-2009; OI Jackson, Catheryn/0000-0003-1611-3926 NR 16 TC 75 Z9 76 U1 2 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 10 PY 2001 VL 34 IS 8 BP 2735 EP 2738 DI 10.1021/ma0008847 PG 4 WC Polymer Science SC Polymer Science GA 419TK UT WOS:000167964600048 ER PT J AU Geltman, S Bambini, A AF Geltman, S Bambini, A TI Triplet scattering lengths for rubidium and their role in Bose-Einstein condensation SO PHYSICAL REVIEW LETTERS LA English DT Article ID NONLINEAR SCHRODINGER-EQUATION; TRAPPED NEUTRAL ATOMS; GROUND-STATE; ATTRACTIVE INTERACTIONS; ELASTIC-SCATTERING; GAS; BOSONS; ENERGY; APPROXIMATION; COLLISIONS AB The triplet scattering lengths of Rb-85 and Rb-87 are evaluated as a function of C-6 using a potential whose short-range form is fitted to an ab initio result. This is combined with a previous analysis of photoassociation measurements, which allows the determination of bounds on C-6 and the scattering amplitudes to give sharper bounds for these quantities. Questions are raised about the use of scattering length as the sole atomic parameter in the description of Bose-Einstein condensates. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. CNR, Ist Elettron Quantist, I-50127 Florence, Italy. RP Geltman, S (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 39 TC 12 Z9 12 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 9 PY 2001 VL 86 IS 15 BP 3276 EP 3279 DI 10.1103/PhysRevLett.86.3276 PG 4 WC Physics, Multidisciplinary SC Physics GA 421CZ UT WOS:000168045700015 PM 11327949 ER PT J AU Chu, SY Tordova, M Gilliland, GL Gorshkova, I Shi, Y Wang, SL Schwarz, FP AF Chu, SY Tordova, M Gilliland, GL Gorshkova, I Shi, Y Wang, SL Schwarz, FP TI The structure of the T127L/S128A mutant of cAMP receptor protein facilitates promoter site binding SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID CAP-DNA COMPLEX; CYCLIC-NUCLEOTIDE BINDING; GENE ACTIVATOR PROTEIN; ESCHERICHIA-COLI; REGULATORY PROTEIN; RESOLUTION; AMP; INTERFACE; MUTAGENESIS; TRANSITION AB The x-ray crystal structure of the cAMP-ligated T127L/ S128A double mutant of cAMP receptor protein (CRP) was determined to a resolution of 2.2 Angstrom Although this structure is close to that of the x-ray crystal structure of cAMP-ligated CRP with one subunit in the open form and one subunit in the closed form, a bound syn-cAMP is clearly observed in the closed subunit in a third binding site in the C-terminal domain. In addition, water-mediated interactions replace the hydrogen bonding interactions between the N-6 of anti-cAMP bound in the N-terminal domains of each subunit and the OH groups of the Thr(127) and Ser(128) residues in the C alpha -helix of wild type CRP, This replacement induces flexibility in the C alpha -helix at Ala(128), which swings the C-terminal domain of the open subunit more toward the N-terminal domain in the T127L/S128A double mutant of CRP (CRP*) than is observed in the open subunit of cAMP-ligated CRP, Isothermal titration calorimetry measurements on the binding of cAMP to CRP* show that the binding mechanism changes from an exothermic independent two-site binding mechanism at pH 7.0 to an endothermic interacting two-site mechanism at pH 5.2, similar to that observed for CRP at both pH levels. Differential scanning calorimetry measurements exhibit a broadening of the thermal denaturation transition of CRP*; relative to that of CRP at pH 7.0 but similar to the multipeak transitions observed for cAMP-ligated CRP. These properties and the bound syn-cAMP ligand, which has only been previously observed in the DNA bound x-ray crystal structure of cAMP-ligated CRP by Passner and Steitz (Passner, J. M., and Steitz, T. A. (1997) Proc. Nafl. Acad. Sci. U.S. A. 94, 2843-2847), imply that the cAMP-ligated CRP* structure is closer to the conformation of the allosterically activated structure than cAMP-ligated CRP. This may be induced by the unique flexibility at Ala128 and/or by the bound syn-cAMP in the hinge region of CRP*. C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland, Inst Biotechnol, Rockville, MD 20850 USA. RP Gilliland, GL (reprint author), NIST, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. NR 38 TC 23 Z9 24 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD APR 6 PY 2001 VL 276 IS 14 BP 11230 EP 11236 DI 10.1074/jbc.M010428200 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 420AC UT WOS:000167980900088 PM 11124966 ER PT J AU Reilly, CA Crouch, DJ Yost, GS Fatah, AA AF Reilly, CA Crouch, DJ Yost, GS Fatah, AA TI Determination of capsaicin, dihydrocapsaicin, and nonivamide in self-defense weapons by liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE pepper spray; capsaicin; dihydrocapsaicin; nonivamide; octanoyl vanillamide ID PEPPER-SPRAY; PAIN; RECEPTOR; CAPSICUM AB Sensitive and selective liquid chromatogaphy-mass spectrometry (LC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS-MS) methods for the analysis of capsaicin, dihydrocapsaicin, and nonivamide in pepper spray products have been developed. Chromatographic separation of the capsaicinoid analogues was achieved using a reversed-phase HPLC column and a stepwise gradient of methanol and distilled water containing 0.1% (v/v) formic acid. Identification and quantification of the capsaicinoids was achieved by electrospray ionization single-stage mass spectrometry monitoring the protonated molecules of the internal standard (m/z 280), capsaicin (m/z 306), dihydrocapsaicin (m/z 308), and nonivamide (m/z 294) or by tandem mass spectrometry monitoring the appropriate precursor-to-product-ion transitions. The ng/ml using LC-MS-MS. However, to accurately quantify the capsaicinoids in the pepper spray products calibration curves between 10 and 1000 ng were constructed and fit using a weighted quadratic equation. Using the quadratic curve, the accuracy of the assay ranged from 91 to 102% for all analytes. The intra-assay precision (RSD) for capsaicin was 2% at 25 ng/ml, 10% at 500 ng/ml, and 3% at 800 ng/ml. The inter-assay precision (RSD) for capsaicin was 6% at 25 ng/ml, 6% at 500 ng/ml, and 9% at 800 ng/ml. Similar values for inter- and intra-assay precision were experimentally obtained for both dihydrocapsaicin and nonivamide. The analysis of selected pepper spray products demonstrated that the capsaicinoid concentration in the products ranged from 0.7 to 40.5 mug/mul. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Utah, Ctr Human Toxicol, Salt Lake City, UT 84112 USA. Univ Utah, Dept Pharmacol & Toxicol, Salt Lake City, UT 84112 USA. Natl Inst Stand & Technol, Off Law Enforcement Stand, Gaithersburg, MD 20899 USA. RP Crouch, DJ (reprint author), Univ Utah, Ctr Human Toxicol, 20 S 2030 E,Room 490, Salt Lake City, UT 84112 USA. NR 22 TC 60 Z9 62 U1 5 U2 35 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD APR 6 PY 2001 VL 912 IS 2 BP 259 EP 267 DI 10.1016/S0021-9673(01)00574-X PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 416WM UT WOS:000167803200006 PM 11330795 ER PT J AU Hoerling, MP Hurrell, JW Xu, TY AF Hoerling, MP Hurrell, JW Xu, TY TI Tropical origins for recent North Atlantic climate change SO SCIENCE LA English DT Article ID PACIFIC-OCEAN; EL NINO; OSCILLATION; VARIABILITY; MIDLATITUDE; TEMPERATURE; SURFACE; TRENDS; TELECONNECTIONS; MODEL AB Evidence is presented that North Atlantic climate change since 1950 is linked to a progressive warming of tropical sea surface temperatures, especially over the Indian and Pacific Oceans. The ocean changes alter the pattern and magnitude of tropical rainfall and atmospheric heating, the atmospheric response to which includes the spatial structure of the North Atlantic Oscillation (NAO), The slow, tropical ocean warming has thus forced a commensurate trend toward one extreme phase of the NAO during the past half-century. C1 NOAA, Climate Diagnost Ctr, Environm Res Labs, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Hoerling, MP (reprint author), NOAA, Climate Diagnost Ctr, Environm Res Labs, Boulder, CO 80303 USA. NR 28 TC 383 Z9 398 U1 4 U2 37 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 APR 6 PY 2001 VL 292 IS 5514 BP 90 EP 92 DI 10.1126/science.1058582 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 420FU UT WOS:000167995200043 PM 11292869 ER PT J AU Bryukov, MG Slagle, IR Knyazev, VD AF Bryukov, MG Slagle, IR Knyazev, VD TI Kinetics of reactions of H atoms with methane and chlorinated methanes SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PLESSET PERTURBATION-THEORY; HIGH-TEMPERATURE PYROLYSIS; ELECTRON-SPIN-RESONANCE; TRANSITION-STATE THEORY; FUEL-RICH; HYDROGEN-ATOMS; CHEMICAL STRUCTURES; RATE CONSTANTS; SHOCK-TUBE; DATA-BASE AB The reactions of H atoms with methane, four chlorinated methanes, and isobutene have been studied experimentally using the discharge flow/resonance fluorescence technique over wide ranges of temperatures. The rate constants were obtained in direct experiments as functions of temperature. The experimentally obtained activation energies of the reactions of H atoms with chlorinated methanes demonstrate a correlation with the enthalpies of the reactions. Transition state theory reaction models were created on the basis of ab initio calculations, the Marcus expression for correlation between reaction barriers and reaction energetics, and analysis of experimental data. It is demonstrated that the formalism based on the Marcus expression adequately describes the observed temperature dependencies of the rate constants of the overall reactions. According to the models, abstraction by H atoms of hydrogen atoms from chloromethanes is an important process accounting for significant fractions of the overall rate constants. The models result in expressions for the rate constants of Cl and H atom abstraction channels and the corresponding reverse reactions over wide ranges of temperatures. C1 Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Knyazev, VD (reprint author), Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA. NR 79 TC 53 Z9 54 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD APR 5 PY 2001 VL 105 IS 13 BP 3107 EP 3122 DI 10.1021/jp0023359 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 419AV UT WOS:000167927900026 ER PT J AU Hass, DD Slifka, AJ Wadley, HNG AF Hass, DD Slifka, AJ Wadley, HNG TI Low thermal conductivity vapor deposited zirconia microstructures SO ACTA MATERIALIA LA English DT Article DE physical vapor deposition (PVD); coating; oxides; thermal conductivity ID BARRIER COATINGS; THIN-FILMS; ADHESION AB Low thermal conductivity yttria stabilized zirconia (YSZ) coatings have been grown using a low-vacuum (0.20 Torr) electron beam directed vapor deposition process. In this approach, a transsonic helium jet was used to entrain and transport an evaporated YSZ flux to a substrate. The interaction of the helium jet with the coating surface resulted in many of the evaporated species making oblique angles of contact with the substrate. This resulted in the formation of a highly porous, columnar microstructure without substrate rotation. When the substrate was positioned perpendicular to the axis of the jet, coatings with intercolumnar pores normal to the substrate surface were formed. The ambient temperature thermal conductivity of a coating grown in this arrangement was 1.9 Wm/K, comparable to that of conventinal, high-vacuum electron beam coatings. When the column and pore orientation was inclined (by tilting the substrate) the thermal conductivity was observed to fall. By alternating the inclination angle as growth progressed, coatings containing zig-zag columns and pores could be synthesized. Using this technique, YSZ coatings with thermal conductivities as low as 0.8 W/m K were obtained. The observed thermal conductivity reduction arises from the longer thermal diffusion path of the zig-zag pore micro-structures. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Virginia, Sch Engn & Appl Sci, Dept Mat Sci, Charlottesville, VA 22903 USA. Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Hass, DD (reprint author), Univ Virginia, Sch Engn & Appl Sci, Dept Mat Sci, Charlottesville, VA 22903 USA. NR 53 TC 98 Z9 101 U1 6 U2 22 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD APR 2 PY 2001 VL 49 IS 6 BP 973 EP 983 DI 10.1016/S1359-6454(00)00403-1 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 420WF UT WOS:000168027700004 ER PT J AU Haljan, PC Anderson, BP Coddington, I Cornell, EA AF Haljan, PC Anderson, BP Coddington, I Cornell, EA TI Use of surface-wave spectroscopy to characterize tilt modes of a vortex in a Bose-Einstein condensate SO PHYSICAL REVIEW LETTERS LA English DT Article ID COLLECTIVE EXCITATIONS; STABILITY; DYNAMICS; VORTICES; STATES; GASES AB A vortex in a condensate in a nonspherical trapping potential will in general experience a torque. The torque will induce tilting of the direction of the vortex axis. We observe this behavior experimentally and show that by applying small distortions to the trapping potential, we can control the tilting behavior. By suppressing vortex tilt, we have been able to hold the vortex axis along the line of sight for up to 15 sec. Alternatively, we can induce a 180 degrees tilt, effectively reversing the charge on the vortex as observed in the lab frame. We characterize the vortex nondestructively with a surface-wave spectroscopic technique. C1 Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Quantum Phys Div, Boulder, CO 80309 USA. RP Haljan, PC (reprint author), Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. RI Anderson, Brian/A-2286-2009 OI Anderson, Brian/0000-0002-0442-7867 NR 18 TC 41 Z9 41 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 APR 2 PY 2001 VL 86 IS 14 BP 2922 EP 2925 DI 10.1103/PhysRevLett.86.2922 PG 4 WC Physics, Multidisciplinary SC Physics GA 417ZX UT WOS:000167866300003 PM 11290073 ER PT J AU Anderson, BP Haljan, PC Regal, CA Feder, DL Collins, LA Clark, CW Cornell, EA AF Anderson, BP Haljan, PC Regal, CA Feder, DL Collins, LA Clark, CW Cornell, EA TI Watching dark solitons decay into vortex rings in a Bose-Einstein condensate SO PHYSICAL REVIEW LETTERS LA English DT Article ID NONLINEAR MEDIA; DYNAMICS; VORTICES; INSTABILITY; PROPAGATION; STABILITY; STATES; BEAMS; GAS AB We have created spatial dark solitons in two-component Bose-Einstein condensates in which the soli ton exists in one of the condensate components and the soliton nodal plane is filled with the second component. The filled solitons are stable for hundreds of milliseconds. The filling can be selectively removed, making the soliton more susceptible to dynamical instabilities. For a condensate in a spherically symmetric potential, these instabilities cause the dark soliton to decay into stable vortex rings. We have imaged the resulting vortex rings. C1 Univ Colorado, JILA, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Quantum Phys Div, Boulder, CO 80305 USA. Lawrence Univ, Dept Phys, Appleton, WI 54912 USA. Natl Inst Stand & Technol, Electron & Opt Phys Div, Gaithersburg, MD 20899 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Univ Colorado, JILA, Natl Inst Stand & Technol, Boulder, CO 80309 USA. RI Anderson, Brian/A-2286-2009; Clark, Charles/A-8594-2009 OI Anderson, Brian/0000-0002-0442-7867; Clark, Charles/0000-0001-8724-9885 NR 28 TC 484 Z9 489 U1 2 U2 21 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 APR 2 PY 2001 VL 86 IS 14 BP 2926 EP 2929 DI 10.1103/PhysRevLett.86.2926 PG 4 WC Physics, Multidisciplinary SC Physics GA 417ZX UT WOS:000167866300004 PM 11290074 ER PT J AU Spal, RD AF Spal, RD TI Submicrometer resolution hard x-ray holography with the asymmetric Bragg diffraction microscope SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNIFIER AB The asymmetric Bragg diffraction microscope is a novel x-ray microscope which forms a magnified in-line near-field hologram by asymmetric reflection from two crossed flat crystals. In this paper, the optics of the microscope is studied theoretically. The optical transfer function is obtained, and the limiting spatial resolution, rated at 25% modulation transfer, is determined to be 0.30 mum at an optimum magnification of 89x with Si crystals, over a wide range of hard x-ray wavelengths. Absorption and phase contrast images can be computed from holograms acquired at several object distances. Application to submicrometer resolution hard x-ray microtomography is envisioned. C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. RP Spal, RD (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. NR 23 TC 28 Z9 29 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 2 PY 2001 VL 86 IS 14 BP 3044 EP 3047 DI 10.1103/PhysRevLett.86.3044 PG 4 WC Physics, Multidisciplinary SC Physics GA 417ZX UT WOS:000167866300033 PM 11290103 ER PT J AU Reis, DA DeCamp, MF Bucksbaum, PH Clarke, R Dufresne, E Hertlein, M Merlin, R Falcone, R Kapteyn, H Murnane, MM Larsson, J Missalla, T Wark, JS AF Reis, DA DeCamp, MF Bucksbaum, PH Clarke, R Dufresne, E Hertlein, M Merlin, R Falcone, R Kapteyn, H Murnane, MM Larsson, J Missalla, T Wark, JS TI Probing impulsive strain propagation with x-ray pulses SO PHYSICAL REVIEW LETTERS LA English DT Article ID STRUCTURAL DYNAMICS; LATTICE-DYNAMICS; DIFFRACTION; GENERATION; PHONONS; FILMS AB Pump-probe time-resolved x-ray diffraction of allowed and nearly forbidden reflections in InSb is used to follow the propagation of a coherent acoustic pulse generated by ultrafast laser excitation. The surface and bulk components of the strain could be simultaneously measured due to the large x-ray penetration depth. Comparison of the experimental data with dynamical diffraction simulations suggests that the conventional model for impulsively generated strain underestimates the partitioning of energy into coherent modes. C1 Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Michigan, Ctr Ultrafast Opt Sci, Ann Arbor, MI 48109 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Lund Inst Technol, Dept Atom Phys, SE-22100 Lund, Sweden. Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. RP Reis, DA (reprint author), Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. RI Kapteyn, Henry/H-6559-2011; OI Kapteyn, Henry/0000-0001-8386-6317; Merlin, Roberto/0000-0002-5584-0248; Dufresne, Eric/0000-0002-2077-4754 NR 22 TC 131 Z9 131 U1 1 U2 20 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 2 PY 2001 VL 86 IS 14 BP 3072 EP 3075 DI 10.1103/PhysRevLett.86.3072 PG 4 WC Physics, Multidisciplinary SC Physics GA 417ZX UT WOS:000167866300040 PM 11290110 ER PT J AU Manley, ME Fultz, B McQueeney, RJ Brown, CM Hults, WL Smith, JL Thoma, DJ Osborn, R Robertson, JL AF Manley, ME Fultz, B McQueeney, RJ Brown, CM Hults, WL Smith, JL Thoma, DJ Osborn, R Robertson, JL TI Large harmonic softening of the phonon density of states of uranium SO PHYSICAL REVIEW LETTERS LA English DT Article ID INELASTIC NEUTRON-SCATTERING; VIBRATIONAL ENTROPY; GAMMA-CERIUM AB Phonon density-of-states curves were obtained from inelastic neutron scattering spectra from the three crystalline phases of uranium at temperatures from 50 to 1213 K. The alpha -phase showed an unusually large thermal softening of phonon frequencies. Analysis of the vibrational power spectrum showed that this phonon softening originates with the softening of a harmonic solid, as opposed to vibrations in anharmonic potentials. It follows that thermal excitations of electronic states are more significant thermodynamically than are the classical volume effects. For the alpha-beta and beta-gamma phase transitions, vibrational and electronic entropies were comparable. C1 CALTECH, Pasadena, CA 91125 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Maryland, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Manley, ME (reprint author), CALTECH, Pasadena, CA 91125 USA. RI Osborn, Raymond/E-8676-2011; Brown, Craig/B-5430-2009; Manley, Michael/N-4334-2015; McQueeney, Robert/A-2864-2016 OI Osborn, Raymond/0000-0001-9565-3140; Brown, Craig/0000-0002-9637-9355; McQueeney, Robert/0000-0003-0718-5602 NR 23 TC 57 Z9 59 U1 3 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 APR 2 PY 2001 VL 86 IS 14 BP 3076 EP 3079 DI 10.1103/PhysRevLett.86.3076 PG 4 WC Physics, Multidisciplinary SC Physics GA 417ZX UT WOS:000167866300041 PM 11290111 ER PT J AU Kim, YJ Birgeneau, RJ Chou, FC Erwin, RW Kastner, MA AF Kim, YJ Birgeneau, RJ Chou, FC Erwin, RW Kastner, MA TI Critical spin dynamics of the 2D quantum Heisenberg antiferromagnets Sr2CuO2Cl2 and Sr2Cu3O4Cl2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID LOW-TEMPERATURES; LA2CUO4 AB We report a neutron scattering study of the long-wavelength dynamic spin correlations in the model two-dimensional S = 1/2 square lattice Heisenberg antiferromagnets Sr2CuO2Cl2 and Sr2Cu3O4Cl2. The characteristic energy scale, omega (0)(T/J), is determined by measuring the quasielastic peak width in the paramagnetic phase over a wide range of temperature (0.2 less than or similar to T/J less than or similar to 0.7). The obtained values for omega (0)(T/J) agree quantitatively between the two compounds and also with values deduced from quantum Monte Carlo simulations. The combined data show scaling behavior, omega similar to xi (-z), over the entire temperature range with z = 1.0(1), in agreement with dynamic scaling theory. C1 MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Kim, YJ (reprint author), MIT, Dept Phys, Cambridge, MA 02139 USA. RI Kim, Young-June /G-7196-2011 OI Kim, Young-June /0000-0002-1172-8895 NR 20 TC 8 Z9 8 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 2 PY 2001 VL 86 IS 14 BP 3144 EP 3147 DI 10.1103/PhysRevLett.86.3144 PG 4 WC Physics, Multidisciplinary SC Physics GA 417ZX UT WOS:000167866300058 PM 11290128 ER PT J AU Allison, TC Gonzalez, CA Louis, F Sawerysyn, JP AF Allison, TC Gonzalez, CA Louis, F Sawerysyn, JP TI Ab initio study of the kinetics of the reactions of H atoms with a series of chloromethanes: Implications in combustion chemistry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Expt Kinet & Thermodynam Grp, Gaithersburg, MD 20899 USA. NIST, Computat Chem Grp, Gaithersburg, MD 20899 USA. Univ Sci & Technol Lille, CNRS, UMR 8522, Lab Cinet & Chim Combust, Lille, France. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 232-PHYS BP U269 EP U269 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801554 ER PT J AU Amis, EJ Sehgal, A Meredith, JC Karim, A AF Amis, EJ Sehgal, A Meredith, JC Karim, A TI Combinatorial methods for materials science: Application to biocompatibility of polymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Div Polymers, MSEL, Gaithersburg, MD 20899 USA. Georgia Inst Technol, Sch Chem Engn, Atlanta, GA 30332 USA. RI Meredith, Carson/B-3323-2009 OI Meredith, Carson/0000-0003-2519-5003 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 70-BTEC BP U464 EP U465 PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802813 ER PT J AU Anderson, DL Lindstrom, RM AF Anderson, DL Lindstrom, RM TI Development of a beam facility for thermal neutron capture prompt gamma-ray activation analysis. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US FDA, Elemental Res Branch, HFS 388, Washington, DC 20204 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 166-NUCL BP U88 EP U88 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824800526 ER PT J AU Bauer, BJ Lin, EK Lee, HJ Wang, H Wu, WL AF Bauer, BJ Lin, EK Lee, HJ Wang, H Wu, WL TI Structure and property characterization of low-k dielectric porous thin films. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 15-POLY BP U297 EP U297 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801737 ER PT J AU Briggman, KA Richter, LJ Wilson, PT Stephenson, JC Wallace, WE AF Briggman, KA Richter, LJ Wilson, PT Stephenson, JC Wallace, WE TI Determination of molecular structure at polymer/glass interfaces by sum-frequency generation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Opt Tech Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Surface & Microanal Div, Gaithersburg, MD 20899 USA. EM kbriggma@nist.gov RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 497-COLL BP U384 EP U384 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824702742 ER PT J AU Briggman, KA Richter, LJ Yang, C Stephenson, JC AF Briggman, KA Richter, LJ Yang, C Stephenson, JC TI Monitoring the real-time, in situ kinetics of self assembly processes by sum frequency generation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Surface & Microanal Div, Gaithersburg, MD 20899 USA. EM kbriggma@nist.gov RI Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 380-COLL BP U366 EP U366 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824702626 ER PT J AU Bubeck, RA Bauer, BJ Dvornic, PR Owen, MJ Reeves, SD Parham, PL Hoffman, LW AF Bubeck, RA Bauer, BJ Dvornic, PR Owen, MJ Reeves, SD Parham, PL Hoffman, LW TI Small-angle neutron scattering from metal ion-containing PAMAMOS dendrimer networks. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Michigan Mol Inst, Midland, MI 48640 USA. Natl Inst Stand & Technol, Bethesda, MD 20892 USA. Dow Corning Corp, Midland, MI 48686 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 480-PMSE BP U431 EP U431 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802610 ER PT J AU Buntin, SA Litorja, M AF Buntin, SA Litorja, M TI Effects of hydrogen and hydrocarbon adsorption on the oxidation of Si(100) by atomic oxygen. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. EM steven.buntin@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 161-COLL BP U332 EP U332 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824702407 ER PT J AU Burden, DL Poppen, SD Elliott, JT Woodward, JT Sehgal, A AF Burden, DL Poppen, SD Elliott, JT Woodward, JT Sehgal, A TI Probing surface diffusion heterogeneity at biomaterial interfaces with single-event histograms. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Wheaton Coll, Dept Chem, Wheaton, IL 60187 USA. Natl Inst Stand & Technol, Wheaton, IL 60187 USA. Natl Inst Stand & Technol, Div Biotechnol, Wheaton, IL 60187 USA. Natl Inst Stand & Technol, Div Polymers, Wheaton, IL 60187 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 145-PHYS BP U249 EP U249 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801469 ER PT J AU Burnett, DJ Marsh, AL Gland, JL Fischer, DA AF Burnett, DJ Marsh, AL Gland, JL Fischer, DA TI In situ studies of CO oxidation on a 100 angstrom Pt/Al2O3 thin film. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Michigan, Dept Chem Engn, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD USA. EM djburnet@engin.umich.edu NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 374-COLL BP U365 EP U365 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824702620 ER PT J AU Cantoni, G Bonner, RF Sehgal, A Douglas, JF Karim, A AF Cantoni, G Bonner, RF Sehgal, A Douglas, JF Karim, A TI High-throughput polymer microwell arrays for Laser Capture Microdissection. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIH, NICHHD, Lab Integrat & Med Biophys, Bethesda, MD 20892 USA. NIST, Div Polymers, MSEL, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 72-BTEC BP U465 EP U465 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802815 ER PT J AU Carlin, RT Fuller, J AF Carlin, RT Fuller, J TI Supported ionic liquid membrane reactors: Energy savings with reduced materials requirements. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Off Naval Res, Phys Sci S&T Div, Arlington, VA 22217 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM carlinr@onr.navy.mil NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 27-IEC BP U558 EP U558 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824703639 ER PT J AU Chin, JW Martin, JW Embree, E Byrd, E Tate, JD AF Chin, JW Martin, JW Embree, E Byrd, E Tate, JD TI Use of integrating spheres as uniform sources for polymer photodegradation studies. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Bldg Mat Grp, Gaithersburg, MD 20899 USA. Dow Chem Co USA, Analyt Sci, Midland, MI 48674 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 405-POLY BP U355 EP U355 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802126 ER PT J AU Cole, KD Tellez, CM Akerman, B AF Cole, KD Tellez, CM Akerman, B TI Electrophoretic trapping and mobility of large circular DNA in gels. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. Chalmers Univ Technol, Dept Phys Chem, S-41296 Gothenburg, Sweden. EM Kenneth.Cole@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 218-BIOT BP U143 EP U143 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824700690 ER PT J AU Cziczo, DJ Murphy, D Thomson, D Dobson, C Ellison, B Tuck, A Vaida, V AF Cziczo, DJ Murphy, D Thomson, D Dobson, C Ellison, B Tuck, A Vaida, V TI Meteoritic and organic material in the atmosphere. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. EM djcziczo@al.noaa.gov NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 167-GEOC BP U543 EP U543 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824703580 ER PT J AU Dickens, S Stansbury, JW Floyd, CJE AF Dickens, S Stansbury, JW Floyd, CJE TI NIR applications for measuring water sorption and vinyl unsaturation in dental dimethacrylate polymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Amer Dent Assoc Hlth Fdn, PRC, Gaithersburg, MD 20899 USA. Univ Colorado, Ctr Hlth Sci, Sch Dent, Biomat Res Ctr, Boulder, CO 80309 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 36-POLY BP U300 EP U300 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801758 ER PT J AU Draxler, AFJ AF Draxler, AFJ TI Biogeochemicals as controlling factors in the behavior and growth of young-of-the-year winter flounder. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA, NMFS, NEFSC, Howard Marine Sci Lab, Highlands, NJ 07732 USA. EM andrew.draxler@noaa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 160-GEOC BP U542 EP U542 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824703573 ER PT J AU Esker, AR Grull, H Satija, SK Han, CC AF Esker, AR Grull, H Satija, SK Han, CC TI Probing polymer dynamics with ultra-thin membranes by neutron reflectivity. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Virginia Polytech Inst & State Univ, Dept Chem, Blacksburg, VA 24061 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 14-POLY BP U296 EP U296 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801736 ER PT J AU Gallagher, T Holden, MJ Mayhew, MP Vilker, VL AF Gallagher, T Holden, MJ Mayhew, MP Vilker, VL TI Protein and enzyme engineering from a structural perspective. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. EM travis.gallagher@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 154-BIOT BP U133 EP U133 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824700628 ER PT J AU Gaune-Escard, M Fuller, J AF Gaune-Escard, M Fuller, J TI Research opportunities derived from the Molten Salt Database project. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Aix Marseille 1, CNRS, Technopole Chateau Gombert, IUSTI, F-13453 Marseille, France. NIST, SRD, Gaithersburg, MD 20899 USA. EM mge@iusti.univ-mrs.fr; joan.fuller@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 281-IEC BP U611 EP U611 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824703894 ER PT J AU Gilman, JW VanderHart, D Asano, A Sutto, TE Awad, W Trulove, PC DeLong, H Davis, RD AF Gilman, JW VanderHart, D Asano, A Sutto, TE Awad, W Trulove, PC DeLong, H Davis, RD TI Recent advances in characterization and processing of flame retardant polymer nanocomposites. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Fire Sci, Mat Fire Res Grp, Gaithersburg, MD 20899 USA. NIST, Div Polymers, Gaithersburg, MD 20899 USA. USN, Res Lab, Div Chem, Washington, DC 20375 USA. USAF, Off Sci Res, Washington, DC USA. USN Acad, Dept Chem, Annapolis, MD 21402 USA. EM jeffrey.gilman@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 291-IEC BP U612 EP U612 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824703904 ER PT J AU Grohn, F Bauer, BJ Kim, G Amis, EJ AF Grohn, F Bauer, BJ Kim, G Amis, EJ TI Nanoparticle formation within dendrimer-containing polymer networks: Route to new organic-inorganic hybrid materials. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 43-PMSE BP U364 EP U364 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802173 ER PT J AU Guttman, CM Blair, WR Wetzel, SJ AF Guttman, CM Blair, WR Wetzel, SJ TI Making MALDI-TOF-MS an absolute method for the determination of the MMD of polymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 37-POLY BP U300 EP U300 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801759 ER PT J AU Han, CC Schmidt, G Nakatani, AI Karim, A AF Han, CC Schmidt, G Nakatani, AI Karim, A TI Characterization of polymer-clay solutions by rheology, flow birefringence and SANS. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 18-POLY BP U297 EP U297 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801740 ER PT J AU Heinz, WF Weston, KD Navarro, B Bernardi, P Goldner, LS AF Heinz, WF Weston, KD Navarro, B Bernardi, P Goldner, LS TI Combined atomic force, confocal, and total internal reflection microscope for the study of single molecules. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Opt Technol, Gaithersburg, MD 20899 USA. EM william.heinz@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 240-COLL BP U344 EP U344 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824702486 ER PT J AU Hodges, AR Fang, Y Heinz, WF Hoh, JH AF Hodges, AR Fang, Y Heinz, WF Hoh, JH TI Probing membrane fusion using atomic force microscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Johns Hopkins Sch Med, Dept Physiol, Baltimore, MD 21205 USA. Corning Inc, Corning, NY USA. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD USA. EM ahodges@jhmi.edu NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 238-COLL BP U344 EP U344 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824702484 ER PT J AU Holmes, GA Feresenbet, E Raghavan, D AF Holmes, GA Feresenbet, E Raghavan, D TI Effect of self-assembled monolayer technology on fiber-matrix adhesion. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymer, Gaithersburg, MD 20899 USA. Howard Univ, Dept Chem, Washington, DC 20059 USA. Howard Univ, Polymer Sci Div, Washington, DC 20059 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 155-POLY BP U316 EP U316 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801877 ER PT J AU Johnson, RD AF Johnson, RD TI NIST computational chemistry comparison and benchmark database. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Computat Chem Grp, Gaithersburg, MD 20899 USA. EM russell.johnson@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 6-CINF BP U279 EP U279 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824702123 ER PT J AU Johnson, WE AF Johnson, WE TI Long term temporal trends of pops in NOAA's Mussel Watch Project compared with trends in other matrices. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA, Natl Ocean Serv, Silver Spring, MD 20910 USA. EM ed.johnson@noaa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 54-ENVR BP U453 EP U453 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824703073 ER PT J AU Kapteyn, HC Murnane, MM Bartels, R Backus, SJ Christov, IP AF Kapteyn, HC Murnane, MM Bartels, R Backus, SJ Christov, IP TI Coherent control of electronic wavefunctions in the strong field regime. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Colorado, Joint Inst Lab Astrophys, Dept Phys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Sofia, Dept Phys, BU-1126 Sofia, Bulgaria. RI Backus, Sterling/C-2506-2008; Kapteyn, Henry/H-6559-2011; Christov, Ivan/D-4446-2014 OI Kapteyn, Henry/0000-0001-8386-6317; Christov, Ivan/0000-0002-9146-6708 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 129-PHYS BP U247 EP U247 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801453 ER PT J AU Karim, A Smith, AP Douglas, JF Amis, E AF Karim, A Smith, AP Douglas, JF Amis, E TI Characterization of symmetric diblock copolymers with high throughput techniques. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 34-POLY BP U299 EP U299 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801756 ER PT J AU Khoury, F AF Khoury, F TI Aspects of the diversity of polymer crystallization habits. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 151-POLY BP U316 EP U316 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801873 ER PT J AU Kim, SD Boczar, EM Bauer, BJ Klein, A Sperling, LH AF Kim, SD Boczar, EM Bauer, BJ Klein, A Sperling, LH TI SANS study of sulfonate end group effect on polystyrene self-diffusion. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Lehigh Univ, Ctr Polymer Sci & Engn, Bethlehem, PA 18015 USA. Rohm & Haas Co, Philadelphia, PA 19104 USA. Natl Inst Stand & Technol, Div Polymer, Bethesda, MD 20892 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 332-PMSE BP U408 EP U408 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802462 ER PT J AU Lauenstein, GG O'Connor, TP AF Lauenstein, GG O'Connor, TP TI US coastal and estuarine surficial sediment trace element and organic contaminant changes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Ctr Coastal Ocean Sci, Natl Ocean & Atmospher Adm, Silver Spring, MD 20901 USA. EM glauenstein@rdc.noaa.gov NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 72-ENVR BP U456 EP U456 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824703091 ER PT J AU Leone, SR AF Leone, SR TI Femtosecond soft x-ray time-resolved photoelectron spectroscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 157-PHYS BP U251 EP U251 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801481 ER PT J AU Lewis, HD Burnett, DJ Gabelnick, AM Gland, JL Fischer, DA AF Lewis, HD Burnett, DJ Gabelnick, AM Gland, JL Fischer, DA TI In situ soft x-ray studies of defect reactivity: Oxidation of CO on Pt(411) in pressures of oxygen. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Michigan, Dept Chem Engn, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD USA. EM lewish@engin.umich.edu NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 373-COLL BP U365 EP U365 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824702619 ER PT J AU Li, XF Ando, Y Ober, CK Sivanliah, E Kramer, EJ Fischer, DA AF Li, XF Ando, Y Ober, CK Sivanliah, E Kramer, EJ Fischer, DA TI Surface self-assembly in side chain modified block copolymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Cornell Univ, Dept Mat Sci & Engn, Ithaca, NY 14853 USA. NIST, Bethesda, MD 20892 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 482-PMSE BP U431 EP U431 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802612 ER PT J AU Louis, F Gonzalez, CA Huie, RE Kurylo, MJ AF Louis, F Gonzalez, CA Huie, RE Kurylo, MJ TI Determination of the potential energy surfaces for the reactions of OH radicals with haloalkanes Implications in atmospheric chemistry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Sci & Technol Lille, CNRS, UMR 8522, Lab Cinet & Chim Combust, F-59655 Villeneuve Dascq, France. Natl Inst Stand & Technol, Computat Chem Grp, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Expt Kinet & Thermodynam Grp, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 237-PHYS BP U270 EP U270 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801559 ER PT J AU Louis, F Gonzalez, CA Huie, RE Kurylo, MJ AF Louis, F Gonzalez, CA Huie, RE Kurylo, MJ TI Conformational properties of a series of hydrofluoroethers: Implications in atmospheric chemistry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Sci & Technol Lille, CNRS, UMR 8522, Lab Cinet & Chim Combust, F-59655 Villeneuve Dascq, France. Natl Inst Stand & Technol, Computat Chem Grp, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Expt Kinet & Thermodynam Grp, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 233-PHYS BP U269 EP U269 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801555 ER PT J AU Marsh, AL Burnett, DJ Fischer, DA Rasmussen, PG Gland, JL AF Marsh, AL Burnett, DJ Fischer, DA Rasmussen, PG Gland, JL TI Near Edge X-Ray Absorption Fine Structure characterization of polymers based on 2-vinyl-4,5-dicyanoimidazole. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 564-PMSE BP U443 EP U443 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802694 ER PT J AU Martter, TD Foster, MD Lizarraga, G Xu, S Yoo, T Quirk, RP Butler, P Majkrzak, CF AF Martter, TD Foster, MD Lizarraga, G Xu, S Yoo, T Quirk, RP Butler, P Majkrzak, CF TI Surface and bulk studies in blends of star and linear polybutadiene. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Akron, Dept Polymer Sci, Akron, OH 44325 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. Natl Inst Stand & Technol, Bethesda, MD 20892 USA. RI Butler, Paul/D-7368-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 379-PMSE BP U415 EP U415 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802509 ER PT J AU Mayhew, MP Holden, MJ Gallagher, T Vilker, VL AF Mayhew, MP Holden, MJ Gallagher, T Vilker, VL TI Chorismate lyase: Understanding the mechanism of product inhibition. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. EM martin.mayhew@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 169-BIOT BP U135 EP U135 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824700643 ER PT J AU Meredith, JC Smith, AP Tona, A Elgendy, H Karim, A Amis, E AF Meredith, JC Smith, AP Tona, A Elgendy, H Karim, A Amis, E TI Combinatorial characterization of complex polymers: Thin film and biomedical polymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Georgia Inst Technol, Sch Chem Engn, Atlanta, GA 30332 USA. NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. NIST, Adv Technol Program, Gaithersburg, MD 20899 USA. RI Meredith, Carson/B-3323-2009 OI Meredith, Carson/0000-0003-2519-5003 NR 0 TC 0 Z9 0 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 588-PMSE BP U447 EP U447 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802718 ER PT J AU Meredith, JC Tona, A Elgendy, H Karim, A Amis, E AF Meredith, JC Tona, A Elgendy, H Karim, A Amis, E TI Combinatorial characterization of biodegradable polymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Georgia Inst Technol, Sch Chem Engn, Atlanta, GA 30332 USA. NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. NIST, Adv Technol Program, Gaithersburg, MD 20899 USA. NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Meredith, Carson/B-3323-2009 OI Meredith, Carson/0000-0003-2519-5003 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 35-POLY BP U299 EP U300 PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801757 ER PT J AU Nakatani, AI Kwan, KS Ivkov, R Papanek, P AF Nakatani, AI Kwan, KS Ivkov, R Papanek, P TI Silica surface treatment effects on the dynamics of poly(dimethyl siloxane) by time-of-flight neutron spectroscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. Dow Corning Corp, Midland, MI 48686 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 268-POLY BP U334 EP U334 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801989 ER PT J AU Nguyen, T Martin, J Byrd, E Embree, N AF Nguyen, T Martin, J Byrd, E Embree, N TI Effects of relative humidity on moisture-enhanced photolysis of acrylic-melamine polymer coatings: A quantitative study. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Bldg Mat Div, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 404-POLY BP U355 EP U355 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802125 ER PT J AU Poskrebyshev, G Neta, P Huie, RE AF Poskrebyshev, G Neta, P Huie, RE TI Reaction of the sulfite radical with ferrous ions in bisulfite solutions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Expt Kinet & Thermodynam Grp, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD USA. EM gposkr@nist.gov; robert.huie@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 115-ENVR BP U462 EP U462 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824703132 ER PT J AU RamachandraRao, V Gupta, R Watkins, JJ Russell, TP Satija, S AF RamachandraRao, V Gupta, R Watkins, JJ Russell, TP Satija, S TI Using supercritical CO2 to enhance surface ordering in block copolymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Massachusetts, Dept Chem Engn, Amherst, MA 01003 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 113-PMSE BP U375 EP U375 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802243 ER PT J AU Reipa, V Niaura, G Mayhew, M Holden, MJ Vilker, V AF Reipa, V Niaura, G Mayhew, M Holden, MJ Vilker, V TI Structural alterations of the active site in Y96F mutant of cytochrome P450cam as deduced by resonance raman spectroscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. Inst Chem, Dept Spect, Vilnius, Lithuania. EM vytas@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 580-INOR BP U725 EP U725 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824704611 ER PT J AU Rumble, J Lee, AY Blakeslee, D Young, S AF Rumble, J Lee, AY Blakeslee, D Young, S TI Supplementing full text journals with factual databases. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. EM john.rumble@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 21-CINF BP U281 EP U281 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824702138 ER PT J AU Stranick, SJ Chase, B Michaels, CA AF Stranick, SJ Chase, B Michaels, CA TI Chemical imaging with scanning near-field IR microscopy and spectroscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Dupont Co Inc, Expt Stn Res, Wilmington, DE USA. EM stephan.stranick@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 173-ANYL BP U96 EP U96 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824700434 ER PT J AU Tees, DFJ Woodward, JT Hammer, DA AF Tees, DFJ Woodward, JT Hammer, DA TI Systematic errors in estimation of Bell model parameters for receptor-ligand bond dissociation from forced unbinding assays. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Penn, Dept Chem Engn, Philadelphia, PA 19104 USA. NIST, Div Biotechnol, Gaithersburg, MD USA. Univ Penn, Dept Bioengn, Philadelphia, PA 19104 USA. EM tees@seas.upenn.edu NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 31-COLL BP U311 EP U311 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824702279 ER PT J AU Tsai, AM Soles, CL Dimeo, RM Neumann, DA Cappelletti, RL AF Tsai, AM Soles, CL Dimeo, RM Neumann, DA Cappelletti, RL TI Low frequency dynamics and its effects on the preservation of biomaterials. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. EM amos.tsai@nist.gov NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 10-BIOT BP U108 EP U108 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PH UT WOS:000168824700489 ER PT J AU Viers, BD Bauer, BJ AF Viers, BD Bauer, BJ TI Kinetics of formation of many armed stars with dendrimer cores as a model of crosslinking. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Polymer Blends & Proc Grp, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 399-PMSE BP U418 EP U418 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802529 ER PT J AU Wallace, WE Guttman, CM Antonucci, J AF Wallace, WE Guttman, CM Antonucci, J TI Mass spectrometry of spin-on-glass low-K dielectric precursors. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 38-POLY BP U300 EP U300 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801760 ER PT J AU Wu, WL Lin, EK Lin, QL Angelopoulos, M AF Wu, WL Lin, EK Lin, QL Angelopoulos, M TI Small angle neutron scattering measurements of nanoscale lithographic features. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Mat Sci & Engn Lab, Div Polymers, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 16-POLY BP U297 EP U297 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824801738 ER PT J AU Yang, S Mirau, PA Pai, CS Nalamasu, O Reichmanis, E Lin, EK Lee, HJ Gidley, D Frieze, WE Dull, TL Sun, J Yee, AF AF Yang, S Mirau, PA Pai, CS Nalamasu, O Reichmanis, E Lin, EK Lee, HJ Gidley, D Frieze, WE Dull, TL Sun, J Yee, AF TI Design of nanoporous ultra low-dielectric constant organosilicates by self-assembly. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. NIST, MSEL, Div Polymers, Bethesda, MD 20894 USA. Natl Inst Stand & Technol, Div Polymer, Bethesda, MD 20894 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 435-PMSE BP U423 EP U424 PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802565 ER PT J AU Yang, S Pai, CS Mirau, P Nalamasu, O Reichmanis, E Lin, EK Gidley, D AF Yang, S Pai, CS Mirau, P Nalamasu, O Reichmanis, E Lin, EK Gidley, D TI Design of ultra low-dielectric constant organosilicates using block copolymers as templates. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Natl Inst Stand & Technol, Bethesda, MD 20894 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 1 PY 2001 VL 221 MA 162-PMSE BP U383 EP U383 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 434PJ UT WOS:000168824802292 ER PT J AU Gayle, F AF Gayle, F TI Fatigue resistant, high temperature solder SO ADVANCED MATERIALS & PROCESSES LA English DT Article C1 Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RP Gayle, F (reprint author), Natl Inst Stand & Technol, Div Met, 100 Bur Dr,MS 8555, Gaithersburg, MD 20899 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0882-7958 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD APR PY 2001 VL 159 IS 4 BP 43 EP 44 PG 2 WC Materials Science, Multidisciplinary SC Materials Science GA 419HN UT WOS:000167943400005 ER PT J AU Seely, JF Brown, CM Holland, GE Hanser, F Wise, J Weaver, JL Korde, R Viereck, RA Grubb, R Judge, DL AF Seely, JF Brown, CM Holland, GE Hanser, F Wise, J Weaver, JL Korde, R Viereck, RA Grubb, R Judge, DL TI Calibration of an extreme-ultraviolet transmission grating spectrometer with synchrotron radiation SO APPLIED OPTICS LA English DT Article ID EFFICIENCY SILICON PHOTODIODES; RESPONSIVITY; PERFORMANCE; DETECTORS; STABILITY AB The responsivity of an extreme-ultraviolet transmission grating spectrometer with silicon photodiode detectors was measured with synchrotron radiation. The spectrometer was designed to record the absolute radiation flux in a wavelength bandpass centered at 30 nm. The transmission grating had a period of 200 nm and relatively high efficiencies in the +1 and the -1 diffraction orders that were dispersed on either aide of the zero-order beam. Three photodiodes were positioned to measure the signals in the zero order and in the +1 and -1 orders. The photodiodes had aluminum overcoatings that passed the desired wavelength bandpass centered at 30 nm and attenuated higher-order radiation and wavelengths longer than approximately 80 nm. The spectrometer's responsivity, the ratio of the photodiode current to the incident radiation power, was determined as a function of the incident wavelength and the angle of the spectrometer with respect to the incident radiation beam. The spectrometer's responsivity was consistent with the product of the photodiode responsivity and the grating efficiency, both of which were separately measured while removed from the spectrometer. C1 USN, Res Lab, Space Sci Div, Washington, DC 20375 USA. Univ So Calif, Ctr Space Sci, Los Angeles, CA 90089 USA. NOAA, Boulder, CO 80303 USA. Int Radiat Detectors Inc, Torrance, CA 90505 USA. Panametr Inc, Waltham, MA 02453 USA. SFA Inc, Landover, MD 20785 USA. RP Seely, JF (reprint author), USN, Res Lab, Space Sci Div, Washington, DC 20375 USA. EM john.seely@nrl.navy.mil NR 20 TC 3 Z9 3 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD APR 1 PY 2001 VL 40 IS 10 BP 1623 EP 1630 DI 10.1364/AO.40.001623 PG 8 WC Optics SC Optics GA 417MY UT WOS:000167839800006 PM 18357156 ER PT J AU Dennis, T Gill, EM Gilbert, SL AF Dennis, T Gill, EM Gilbert, SL TI Interferometric measurement of refractive-index change in photosensitive glass SO APPLIED OPTICS LA English DT Article ID OPTICAL-FIBERS; SILICA; GERMANOSILICATE; DENSIFICATION AB We report on a technique for determining the change in the refractive index of photosensitive glass. We have demonstrated our interferometer-based technique on fiber preform and bulk glass samples, achieving an optical-path-difference (OPD) repeatability of 0.2 nm. For the bulk glass sample we measured an OPD of 15.2 +/- 3.0 nm, corresponding to an index change of 2.1 +/- 0.7 x 10(-5). Our technique was found to be insensitive to the effects of photodarkening and material compaction. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80305 USA. EM tasshi@boulder.nist.gov NR 11 TC 12 Z9 12 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD APR 1 PY 2001 VL 40 IS 10 BP 1663 EP 1667 DI 10.1364/AO.40.001663 PG 5 WC Optics SC Optics GA 417MY UT WOS:000167839800011 PM 18357161 ER PT J AU Colle, R AF Colle, R TI Calibration of P-32 "hot-wall" angioplasty-balloon-catheter sources by liquid-scintillation-spectrometry-based destructive radionuclidic assays SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID INTRAVASCULAR BRACHYTHERAPY; RADIATION; PREVENTION; RESTENOSIS; PHYSICS AB A very quantitative, destructive-analysis procedure was devised for assaying the P-32 activity content of "hot-wall" angioplasty-balloon catheters. These sources, developed and under investigation by Radiance Medical Systems, Inc. (Irvine, CA), are intended for use in the prophylactic inhibition of restenosis following balloon angioplasty in heart-disease patients. The assay was based on performing a physicochemical digestion of the balloon catheter to extract the P-32 activity followed by liquid-scintillation (LS) spectrometry of the resultant solutions. Measurement-based corrections were applied fur the residual activity remaining in the digested balloon debris and in all of the digestion apparatus. The LS spectrometry. with H-3-standard efficiency tracing, utilized a previously-developed method for resolving the always-present P-33 impurity. Initial ionization current measurements on the sources prior to the destructive assays led to the establishment of calibration factors that can be used for subsequent non-destructive radionuclidic measurements on similar balloon-catheter sources. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. RP Colle, R (reprint author), Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. NR 26 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD APR PY 2001 VL 54 IS 4 BP 611 EP 622 DI 10.1016/S0969-8043(00)00315-8 PG 12 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 401TT UT WOS:000166944900004 PM 11225697 ER PT J AU Zimmerman, BE Unterweger, MP Brodack, JW AF Zimmerman, BE Unterweger, MP Brodack, JW TI The standardization of Lu-177 by 4 pi ss liquid scintillation spectrometry with H-3-standard efficiency tracing SO APPLIED RADIATION AND ISOTOPES LA English DT Article DE efficiency tracing; liquid scintillation counting; lutetium-177; standardization ID INTRAPERITONEAL RADIOIMMUNOTHERAPY; OVARIAN-CANCER AB Solutions containing the potential radiotherapy radionuclide Lu-177 have been standardized at the National Institute of Standards and Technology (NIST) by 4 pi beta liquid scintillation (LS) counting with H-3-standard efficiency tracing using the CIEMAT/NIST method. Confirmatory measurements were made with 4 pi NaI(Tl) gamma -ray spectrometry. Activity determinations were made on 4 solutions over the course of 10 months with an expanded (k = 2) uncertainty on the activity of 0.8%. Half-life measurements were carried out using the NIST "4 pi" gamma ionization chamber (IC) and LS counting and gave a new value of 6.65 +/- 0.01d, which is shorter than the current ENSDF-recommended value bq 1.3%. Impurity analyses were performed by high-purity germanium (HPGe) gamma -ray spectrometry and indicated only the presence of Lu-177m at a level of 0.02% that of the Lu-177 as of the respective reference times: for the four solutions. Calibration factors fur the NIST IC and Vinten 671 ionization chambers were developed, as were dial settings for the NIST-maintained Capintec CRC-12, Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. Mallinckrodt Inc, Nucl Med R&D, St Louis, MO 63134 USA. RP Zimmerman, BE (reprint author), Natl Inst Stand & Technol, Phys Lab, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 14 TC 10 Z9 10 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD APR PY 2001 VL 54 IS 4 BP 623 EP 631 DI 10.1016/S0969-8043(00)00316-X PG 9 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 401TT UT WOS:000166944900005 PM 11225698 ER PT J AU Myers, JM Hershberger, WK Saxton, AM Iwamoto, RN AF Myers, JM Hershberger, WK Saxton, AM Iwamoto, RN TI Estimates of genetic and phenotypic parameters for length and weight of marine net-pen reared coho salmon (Oncorhynchus kisutch Walbaum) SO AQUACULTURE RESEARCH LA English DT Article DE aquaculture; coho; genetics; heritability; salmon ID RAINBOW-TROUT; CHINOOK SALMON; BODY-WEIGHT; GROWTH; SMOLTIFICATION; HERITABILITIES; PERFORMANCE; SELECTION; MATURITY; CULTURE AB Heritabilities and genetic and phenotypic correlations were estimated for length and weight of two brood years (BY 1977 and BY 1978) of coho salmon [Oncorhynchus kisutch (Walbaum)] during the marine net-pen phase of rearing. The estimates were calculated from length and weight measurements on progeny resulting from a nested mating design and measurements at approximately 4 and 7 months after entering sea water. Point estimate for heritabilities based on the sire component for BY 1977 were low to moderate (0.02-0.19) and did not differ significantly from zero. On the other hand, BY 1978 estimates ranged from 0.31 to 0.62 and, with two exceptions, were significantly different from zero, The latter estimates may have been inflated by inclusion of variances from non-additive sources, but still indicated that differences in the genetic potential for increased growth between the two pear classes may be substantial. Genetic correlations between length and weight within sampling periods were consistently high (0.95-1.00), indicating that pleiotropic gene action or close linkage among genes affects length and weight. Genetic correlations between body size traits (length and weight) between sampling periods varied considerably but suggested a potential for indirect selection gains. Genetic correlation approximations derived using family means or ranks appeared to provide reliable estimates and may be useful when environmental influences cause a significant deviation from normality. C1 Natl Marine Fisheries Serv, NOAA, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. ARS, Leetown, WV USA. Louisiana State Univ, Dept Expt Stat, Baton Rouge, LA 70803 USA. RP Myers, JM (reprint author), Natl Marine Fisheries Serv, NOAA, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 25 TC 14 Z9 27 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1355-557X J9 AQUAC RES JI Aquac. Res. PD APR PY 2001 VL 32 IS 4 BP 277 EP 285 DI 10.1046/j.1365-2109.2001.00556.x PG 9 WC Fisheries SC Fisheries GA 420LC UT WOS:000168005600004 ER PT J AU Brandt, JC Heap, SR Walter, FM Beaver, EA Boggess, A Carpenter, KG Ebbets, DC Hutchings, JB Jura, M Leckrone, DS Linsky, JL Maran, SP Savage, BD Smith, AM Trafton, LM Weymann, RJ Norman, D Redfield, S AF Brandt, JC Heap, SR Walter, FM Beaver, EA Boggess, A Carpenter, KG Ebbets, DC Hutchings, JB Jura, M Leckrone, DS Linsky, JL Maran, SP Savage, BD Smith, AM Trafton, LM Weymann, RJ Norman, D Redfield, S TI AB Dor in '94. I. Hubble Space Telescope Goddard High Resolution Spectrograph observations of the quiescent chromosphere of an active star SO ASTRONOMICAL JOURNAL LA English DT Article DE ISM : kinematics and dynamics; stars : activity; stars : chromospheres; stars : individual (AB Doradus) ID EVOLUTIONARY STATUS; INTERSTELLAR GAS; FAR-ULTRAVIOLET; EMISSION-LINE; LOCAL CLOUD; HD 36705; DORADUS; SOLAR; SPECTROSCOPY; ABUNDANCES AB We analyze Hubble Space Telescope/Goddard High Resolution Spectrograph spectra of AB Doradus, the prototypical, ultrarapidly rotating K dwarf. We observed chromospheric (Mg II) and transition-region (C II, Si IV, C IV, and N V) lines periodically throughout the stellar rotation period and provide a low-dispersion stellar atlas of 78 emission lines. The quiescent line profiles of the chromospheric and transition-region lines show narrow cores superposed on very broad wings. The broad wings of the Mg II k and h lines and of the transition-region lines can be explained by emission from gas corotating with the star and extending out to near the Keplerian corotation radius (2.8 stellar radii). While this is not a unique solution, it is consistent with previous studies of Ha emission, which are naturally explained by large corotating prominences. We find no evidence for rotational modulation of the emission-line fluxes. The density diagnostics suggest that the transition region is formed at constant pressure, with an electron density of 2-3 x 10(12) cm(-3) at a temperature of 3 x 10(4) K. The electron pressure is about 100 times larger than that for the quiet Sun. The emission-measure distribution shows a minimum between log T = 5 and 5.5. The Mg II line exhibits three interstellar absorption components along the 15 pc line of sight. We identify the lowest velocity component with the G Cloud, but the other components are not identified with any interstellar clouds previously detected from other lines of sight. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. Ball Aerosp & Technol Corp, Boulder, CO 80306 USA. Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Space Sci Directorate, Greenbelt, MD 20771 USA. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Univ Texas, MacDonald Observ, Austin, TX 78712 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. RP Univ New Mexico, Dept Phys & Astron, Inst Astrophys, 800 Yale Blvd, Albuquerque, NM 87131 USA. RI heap, sara/E-2237-2012; Carpenter, Kenneth/D-4740-2012 NR 51 TC 20 Z9 20 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD APR PY 2001 VL 121 IS 4 BP 2173 EP 2184 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 420UA UT WOS:000168022600029 ER PT J AU Mesnick, SL AF Mesnick, SL TI Genetic relatedness in sperm whales: Evidence and cultural implications SO BEHAVIORAL AND BRAIN SCIENCES LA English DT Editorial Material ID POPULATION-STRUCTURE; DIVERSITY; SELECTION; PATTERNS; DIALECTS AB Results of genetic analyses show that social groups of female and immature sperm whales are comprised of multiple matrilines as evidenced by the presence of multiple mitochondrial (maternally inherited) control region haplotypes. These data suggest: (1) a social environment in which the transmission of cultural information, such as vocal dialects, is more likely to, be horizontal or oblique rather than strictly vertical (mother-offspring) and (2) lead us to question the data presented to support gene-culture coevolution. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Mesnick, SL (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. NR 18 TC 29 Z9 29 U1 1 U2 10 PU CAMBRIDGE UNIV PRESS PI PORT CHESTER PA 110 MIDLAND AVE, PORT CHESTER, NY 10573-9863 USA SN 0140-525X J9 BEHAV BRAIN SCI JI Behav. Brain Sci. PD APR PY 2001 VL 24 IS 2 BP 346 EP + DI 10.1017/S0140525X01463965 PG 12 WC Psychology, Biological; Behavioral Sciences; Neurosciences SC Psychology; Behavioral Sciences; Neurosciences & Neurology GA 458DL UT WOS:000170177900086 ER PT J AU Johnson, JB AF Johnson, JB TI Hierarchical organization of genetic variation in the Costa Rican livebearing fish Brachyrhaphis rhabdophora (Poeciliidae) SO BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Article DE allozyme; biogeography; control region; gene flow; genetic distance; geographic variation; kin-structured colonization; mtDNA; population differentiation; polymorphism ID MITOCHONDRIAL-DNA; PHYLOGENETIC-RELATIONSHIPS; POPULATION-STRUCTURE; FLOW; DROSOPHILA; SELECTION; EVOLUTION; DISTANCE; HISTORY AB I examined the geographic distribution of genetic variation in the livebearing freshwater fish Brachyrhaphis rhabdophora in northwestern Costa Rica as revealed by allozymes and mitochondrial DNA sequences. Allelic variability at 11 enzyme-coding loci surveyed across 12 localities revealed marked genetic differentiation among populations within drainages (theta (P) = 0.36) and among drainages within regions (theta (D) = 0.17), but not between northern and southern geographic regions (theta (R) = -0.02). Allozyme variation was hierarchically organized such that populations found within stream drainages were more similar to each other than to populations found in adjacent drainages, a result confirmed by cluster analysis. In contrast to the allozyme data, there was extremely little DNA sequence variation among populations in the mitochondrial control region (3 variable nucleotide positions out of 444 bp examined). The difference in genetic divergence between allozyme and mtDNA markers was unexpected and is discussed in terms of biogeographical colonization events and a molecular selective sweep on the mitochondrial genome, both processes that could explain the lack of mitochondrial variability in this highly subdivided species. (C) 2001 The Linnean Society of London. C1 Univ Vermont, Dept Biol, Burlington, VT 05405 USA. RP Johnson, JB (reprint author), NOAA, Natl Marine Fisheries Serv, Conservat Biol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 31 TC 18 Z9 18 U1 0 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0024-4066 J9 BIOL J LINN SOC JI Biol. J. Linnean Soc. PD APR PY 2001 VL 72 IS 4 BP 519 EP 527 DI 10.1006/bijl.2000.0513 PG 9 WC Evolutionary Biology SC Evolutionary Biology GA 437RM UT WOS:000169007400003 ER PT J AU Wilczak, JM Oncley, SP Stage, SA AF Wilczak, JM Oncley, SP Stage, SA TI Sonic anemometer tilt correction algorithms SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE anemometers; coordinate systems; sloping terrain; surface layer; tilt corrections ID ATMOSPHERIC SURFACE-LAYER; FLOW DISTORTION; TEMPERATURE; TURBULENCE; BUDGETS; SIMILARITY; FLUX AB The sensitivity of sonic anemometer-derived stress estimates to the tilt of the anemometer is investigated. The largest stress errors are shown to occur for unstable stratification (z/L < 0) and deep convective boundary layers. Three methods for determining the tilt angles relative to a mean streamline coordinate system and for computing the tilt-corrected stresses are then compared. The most commonly used method, involving a double rotation of the anemometers' axes, is shown to result in significant run-to-run stress errors due to the sampling uncertainty of the mean vertical velocity. An alternative method, requiring a triple rotation of the anemometer axes, is shown td result in even greater run-to-run stress errors due to the combined sampling errors of the mean vertical velocity and the cross-wind stress. For measurements over the sea where the cross-stream stress is important, the double rotation method is shown to overestimate the surface stress, due to the uncorrected lateral tilt component. A third method, using a planar fit technique, is shown to reduce the run-to-run stress errors due to sampling effects, and provides an unbiased estimate of the lateral stress. C1 NOAA, Environm Res Labs, Environm Technol Lab, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80303 USA. Innovat Emergency Management, Baton Rouge, LA 70809 USA. RP Wilczak, JM (reprint author), NOAA, Environm Res Labs, Environm Technol Lab, Boulder, CO 80303 USA. NR 28 TC 713 Z9 802 U1 10 U2 82 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 APR PY 2001 VL 99 IS 1 BP 127 EP 150 DI 10.1023/A:1018966204465 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 415QQ UT WOS:000167734500006 ER PT J AU Moles, A Wade, TL AF Moles, A Wade, TL TI Parasitism and phagocytic function among sand lance Ammodytes hexapterus pallas exposed to crude oil-laden sediments SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID CONTAMINATED SEDIMENTS; EXXON-VALDEZ; AROMATIC-HYDROCARBONS; POLLUTION; SPILL C1 NOAA, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. Texas A&M Univ, Geochem & Environm Res Grp, College Stn, TX 77845 USA. RP Moles, A (reprint author), NOAA, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. RI Wade, Terry/A-4012-2012 NR 17 TC 18 Z9 20 U1 1 U2 7 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 APR PY 2001 VL 66 IS 4 BP 528 EP 535 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 411VA UT WOS:000167518900019 PM 11443318 ER PT J AU Palka, DL Hammond, PS AF Palka, DL Hammond, PS TI Accounting for responsive movement in line transect estimates of abundance SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID PHOCOENA-PHOCOENA AB A method is developed to account for effects of animal movement in response to sighting platforms in line transect density estimates using data on animal orientation. Models of expected distributions of animal orientation show that presence of responsive movement is determined by the ratio of animal sightings with angles of orientation in the third quadrant relative to the first quadrant. The distance at which response began is estimated using logistic generalized additive models of the relationship between radial distance and orientation. Density corrected for responsive movement is estimated by applying the Buckland and Turnock two-team analysis method to data poststratified into regions "close" to and "far" from (beyond the distance that responsive movement began) the observation platform instead of the original stratification by observation team. For data collected in the North Atlantic, white-sided dolphins, harbor porpoises, and minke whales responded by avoiding the survey ship, and white-beaked dolphins were attracted to the ship. For these populations, our method to correct for responsive movement gave significantly higher estimates, from 1.4 to 2.7 times the uncorrected estimates. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. Univ St Andrews, Sea Mammal Res Unit, Gatty Marine Lab, St Andrews KY16 8LB, Fife, Scotland. RP Palka, DL (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 27 TC 41 Z9 47 U1 0 U2 13 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 APR PY 2001 VL 58 IS 4 BP 777 EP 787 DI 10.1139/cjfas-58-4-777 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 418TG UT WOS:000167907000013 ER PT J AU Berejikian, BA Tezak, EP Park, L LaHood, E Schroder, SL Beall, E AF Berejikian, BA Tezak, EP Park, L LaHood, E Schroder, SL Beall, E TI Male competition and breeding success in captively reared and wild coho salmon (Oncorhynchus kisutch) SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID ATLANTIC SALMON; REPRODUCTIVE-BEHAVIOR; AGONISTIC BEHAVIOR; SOCKEYE-SALMON; PACIFIC SALMON; RAINBOW-TROUT; HATCHERY; PERFORMANCE; SELECTION; TACTICS AB In the Pacific Northwest, releasing captively reared adult salmon (Oncorhynchus spp.) for natural spawning is an evolving strategy for the recovery of imperiled populations. However, the ability of captively reared fish to spawn naturally may be compromised by their artificial rearing environments. In this study, wild coho salmon (O. kisutch) males outcompeted captively reared males and controlled access to spawning females in 11 of 14 paired trials in laboratory stream channels. In two cases where satellite males were observed participating in spawning, DNA genotyping results determined that they did not sire any of the progeny. When spawning occurred at night and was not observed, DNA results confirmed behavior-based determinations of dominance made before dark. Dominance was established soon after the males were introduced into a common arena containing a sexually active female. We hypothesize that decisions by subordinate males to avoid direct competition may have minimized conflict. The competitive inferiority of captively reared coho salmon in this and a previous study probably reflects deficiencies in rearing environments, which fail to produce appropriate body coloration and body shape and perhaps alter natural behavioral development. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Resource Enhancement & Utilizat Technol Div, Manchester, WA 98353 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98112 USA. Washington Dept Fish & Wildlife, Olympia, WA 98501 USA. Inst Natl Rech Agron, Stn Hydrobiol, F-64210 St Pee Sur Nivelle, France. RP Berejikian, BA (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Resource Enhancement & Utilizat Technol Div, POB 130, Manchester, WA 98353 USA. NR 37 TC 33 Z9 35 U1 1 U2 10 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 APR PY 2001 VL 58 IS 4 BP 804 EP 810 DI 10.1139/cjfas-58-4-804 PG 7 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 418TG UT WOS:000167907000016 ER PT J AU Taylor, MK Akeeagok, S Andriashek, D Barbour, W Born, EW Calvert, W Cluff, HD Ferguson, S Laake, J Rosing-Asvid, A Stirling, I Messier, F AF Taylor, MK Akeeagok, S Andriashek, D Barbour, W Born, EW Calvert, W Cluff, HD Ferguson, S Laake, J Rosing-Asvid, A Stirling, I Messier, F TI Delineating Canadian and Greenland polar bear (Ursus maritimus) populations by cluster analysis of movements SO CANADIAN JOURNAL OF ZOOLOGY LA English DT Article ID SEALS PHOCA-HISPIDA; NORTHWEST-TERRITORIES; LANCASTER SOUND; ICE; ABUNDANCE; PREDATION; DYNAMICS; PATTERNS; HABITAT AB Within their circumpolar range, polar bears (Ursus maritimus) are not subject to absolute barriers. However, physiographic features do cause discontinuities in their movements. These discontinuities in distribution can be used to delineate population units. Based on satellite telemetry of the movements of female polar bears carried out in 1989-1998, we used cluster analysis to identify 6 regions within the Canadian and western Greenland Arctic in which movements appear to be restricted enough to identify distinct populations. These regions generally correspond to management units that have been previously identified as Viscount Melville Sound, Lancaster Sound, Norwegian Bay, Kane Basin, Baffin Bay, and Davis Strait. A north-south substructure was identified for the Baffin Bay population, but it was weaker than the structure identified for the 6 primary units. The 6 units were consistent with genetic information, except for the Baffin Bay - Kane Basin separation, and with mark-recapture observations and the traditional knowledge of Inuit hunters. Only 2 of 65 bears that provided telemetry information for more than 1 year were classified in different populations in different years. However, annual rates of exchange, measured as the percentage of locations outside the population boundary, ranged from 0.4 to 8.9%. Analysis of mark-recapture movements indicated no difference in large-scale movements between the sexes or long-term movements with age. Although our validation criteria for demographic closure were satisfied, the observed rates of exchange between adjacent populations suggest that population dynamics in adjacent populations may not be completely independent. C1 Govt Nunavut, Dept Sustainable Dev, Iqaluit, NT X0A 0H0, Canada. Govt Nunavut, Dept Sustainable Dev, Grise Fiord, NT X0H 0H0, Canada. Canadian Wildlife Serv, Edmonton, AB T6H 3S5, Canada. Labrador Inuit Assoc, Nain, NF A0P 1L0, Canada. Greenland Inst Nat Resources, DK-3900 Nuuk, Greenland. Govt NW Terr, Dept Resources Wildlife & Econ Dev, Yellowknife, NT X1A 2P9, Canada. Univ Saskatchewan, Dept Biol, Saskatoon, SK S7N 5E2, Canada. Natl Marine Fisheries Serv, Natl Marine Mammal Lab, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Taylor, MK (reprint author), Govt Nunavut, Dept Sustainable Dev, POB 1000,Stn 1170, Iqaluit, NT X0A 0H0, Canada. EM mtaylor1@gov.nu.ca NR 70 TC 58 Z9 60 U1 1 U2 20 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0008-4301 EI 1480-3283 J9 CAN J ZOOL JI Can. J. Zool. PD APR PY 2001 VL 79 IS 4 BP 690 EP 709 DI 10.1139/cjz-79-4-690 PG 20 WC Zoology SC Zoology GA 423JH UT WOS:000168172400018 ER PT J AU Gabriele, CM Straley, JM Mizroch, SA Baker, CS Craig, AS Herman, LM Glockner-Ferrari, D Ferrari, MJ Cerchio, S von Ziegesar, O Darling, J McSweeney, D Quinn, TJ Jacobsen, JK AF Gabriele, CM Straley, JM Mizroch, SA Baker, CS Craig, AS Herman, LM Glockner-Ferrari, D Ferrari, MJ Cerchio, S von Ziegesar, O Darling, J McSweeney, D Quinn, TJ Jacobsen, JK TI Estimating the mortality rate of humpback whale calves in the central North Pacific Ocean SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID MEGAPTERA-NOVAEANGLIAE; PERSPECTIVE; WATERS AB Sighting histories of individually identified female humpback whales (Megaptera novaeangliae) in their winter and summer ranges were used to investigate mortality of North Pacific humpback whale calves. We compiled records collected between 1979 and 1995 by eight independent research groups, which yielded 29 cases where 25 different mothers sighted in Hawai'i were identified later the same year in Alaska. In 7 of 29 cases, a calf sighted with its mother in Hawai'i was missing from its mother's Alaska sighting(s). After investigating many factors, we determined that the largest potential bias would occur in late-autumn observations, when calf absences might indicate weaning or temporary mother-calf separation rather than calf mortality. Our minimal and most robust estimate excluded all mortalities and survivals based on sightings of the mother after October 31; 3 of 20 cases or 0.150 (95% confidence intervals (CI) = 0.032, 0.378). The maximal calf mortality rate, derived from all the available data, was 7 of 29 cases or 0.241 (95% CI = 0.103, 0.434). An intermediate estimate that excluded all cases based on single Alaska sightings and omitted late-season sightings (2 of 11 cases or 0.182; 95% CI = 0.023, 0.518) is perhaps closest to the actual first-year mortality rate for humpback whale calves, although it is compromised by its small sample size. Our results demonstrate both the value and the limitations of using longitudinal data to determine the life-history parameters that are essential for documenting the recovery of endangered populations. C1 Glacier Bay Natl Pk, Gustavus, AK 99826 USA. Univ Hawaii, Kewalo Basin Marine Mammal Lab, Honolulu, HI 96814 USA. Univ Alaska SE, Sitka, AK 99835 USA. NOAA, Natl Marine Mammal Lab, Seattle, WA 98115 USA. Ctr Whale Studies, Lahaina, HI 96767 USA. Moss Landing Marine Labs, Moss Landing, CA 95039 USA. N Gulf Ocean Soc, Homer, AK 99603 USA. W Coast Whale Res Fdn, Tofino, BC V0R 2Z0, Canada. Univ Alaska, Juneau Ctr Fisheries & Ocean Sci, Juneau, AK 99801 USA. Humboldt State Univ, Arcata, CA 95521 USA. RP Gabriele, CM (reprint author), Glacier Bay Natl Pk, POB 140, Gustavus, AK 99826 USA. RI Mizroch, Sally/M-6084-2016 OI Mizroch, Sally/0000-0002-1736-5909 NR 42 TC 25 Z9 26 U1 2 U2 13 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 APR PY 2001 VL 79 IS 4 BP 589 EP 600 DI 10.1139/cjz-79-4-589 PG 12 WC Zoology SC Zoology GA 423JH UT WOS:000168172400007 ER PT J AU Charles, CD Rind, D Healy, R Webb, R AF Charles, CD Rind, D Healy, R Webb, R TI Tropical cooling and the isotopic composition of precipitation in general circulation model simulations of the ice age climate SO CLIMATE DYNAMICS LA English DT Article ID LAST GLACIAL MAXIMUM; SEA-SURFACE TEMPERATURE; RECORDS; OCEAN; ATMOSPHERE; SHEETS; CORE; DELTA-O-18; CYCLES; LEVEL AB We test the climate effects of changes in the tropical ocean by imposing three different patterns of tropical SSTs in ice age general circulation model simulations that include water source tracers and water isotope tracers. The continental air temperature and hydrological cycle response in these simulations is substantial and should be directly comparable to the paleoclimatic record. With tropical cooling imposed, there is a strong temperature response in mid- to high-latitudes resulting from changes in sea ice and disturbance of the planetary waves; the results suggest that tropical/subtropical ocean cooling leads to significant dynamical and radiative feedbacks that might amplify ice age cycles, The isotopes in precipitation generally follow the temperature response at higher latitudes, but regional delta O-18/air temperature scaling factors differ greatly among the experiments. In low-latitudes, continental surface temperatures decrease congruently with the adjacent SSTs in the cooling experiments. Assuming CLIMAP SSTs, O-18/O-16 ratios in low-latitude precipitation show no change from modern values. However, the experiments with additional cooling of SSTs produce much lower tropical continental delta O-18 values, and these low values result primarily from an enhanced recycling of continental moisture (as marine evaporation is reduced). The water isotopes are especially sensitive to continental aridity, suggesting that they represent an effective tracer of the extent of tropical cooling and drying. Only one of the tropical cooling simulations produces generalized low-latitude aridity. These results demonstrate that the geographic pattern of cooling is most critical for promoting much drier continents, and they underscore the need for accurate reconstructions of SST gradients in the ice age ocean. C1 Scripps Inst Oceanog, La Jolla, CA 92093 USA. Goddard Inst Space Studies, New York, NY 10025 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. NOAA, OAR, CDC, Boulder, CO 80303 USA. RP Charles, CD (reprint author), Scripps Inst Oceanog, La Jolla, CA 92093 USA. RI Healy, Richard/J-9214-2015 OI Healy, Richard/0000-0002-5098-8921 NR 43 TC 13 Z9 15 U1 0 U2 5 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD APR PY 2001 VL 17 IS 7 BP 489 EP 502 DI 10.1007/s003820000126 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 427AZ UT WOS:000168383800001 ER PT J AU Zhao, LZ Vijay, PC Chen, W Demirbilek, Z Chhabbra, N AF Zhao, LZ Vijay, PC Chen, W Demirbilek, Z Chhabbra, N TI Simulation of wave breaking effects in two-dimensional elliptic harbor wave models SO COASTAL ENGINEERING LA English DT Article DE wave; model; mild-slope equation; breaking; elliptic model ID LINEAR WATER-WAVES; COASTAL REGIONS; PROPAGATION; DIFFRACTION; REFRACTION; TRANSFORMATION; HEIGHT; ZONE AB A technique is developed for including the effects of dissipation due to wave breaking in two-dimensional elliptic models based on the mild-slope wave equation. This involves exploration of convergence properties pertaining to iteration due to presence of the nonlinear wave breaking parameter in the governing equations as well as new boundary conditions that include wave-breaking effects. Five wave-breaking formulations are examined in conjunction with the resulting model, which is applied to tests involving a sloping beach, a bar-trough bottom configuration, shore-connected and shore-parallel breakwaters on a sloping beach, and two real-world cases. Model results show that three of the formulations, when used within the context of the modeling scheme presented here, provide excellent results compared to data. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Maine, Dept Civil Engn, Orono, ME 04469 USA. Univ Maine, Sch Marine Sci, Orono, ME 04469 USA. USA, Engineer Res & Dev Ctr, Coastal & Hydraul Lab, Vicksburg, MS 39180 USA. GE Power Syst, Schenectady, NY 12345 USA. RP Vijay, PC (reprint author), NOAA, US Dept Commerce, NSGO, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 39 TC 21 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3839 J9 COAST ENG JI Coast. Eng. PD APR PY 2001 VL 42 IS 4 BP 359 EP 373 DI 10.1016/S0378-3839(00)00069-7 PG 15 WC Engineering, Civil; Engineering, Ocean SC Engineering GA 410AC UT WOS:000167417000005 ER PT J AU Olson, SL Kashiwagi, T Fujita, O Kikuchi, M Ito, K AF Olson, SL Kashiwagi, T Fujita, O Kikuchi, M Ito, K TI Experimental observations of spot radiative ignition and subsequent three-dimensional flame spread over thin cellulose fuels SO COMBUSTION AND FLAME LA English DT Article ID SPEED CONCURRENT FLOW; SOLID-FUEL; MICROGRAVITY ENVIRONMENT; TRANSITION; OXYGEN; MODEL AB Non-piloted radiative ignition and transition to flame spread over thin cellulose fuel samples was studied aboard the USMP-3 STS-75 Space Shuttle mission, and in three test series in the 10 second Japan Microgravity Center (JAMIC). A focused beam from a tungsten/halogen lamp was used to ignite the center of the fuel sample while an external air flow was varied from 0 to 10 cm/s. Non-piloted radiative ignition of the paper was found to occur more easily in microgravity than in normal gravity. ignition of the sample was achieved under all conditions studied (shuttle cabin air, 21%-50% O-2 in JAMIC), with transition to flame spread occurring for all but the lowest oxygen and Bow conditions. Although radiative ignition in a quiescent atmosphere was achieved, the flame quickly extinguished in air. The ignition delay time was proportional to the gas-phase mixing time, which is estimated by using the inverse flow rate. The ignition delay was a much stranger function of Bow at lower oxygen concentrations. After ignition, the flame initially spread only upstream, in a fan-shaped pattern. The fan angle increased with increasing external flow and oxygen concentration from zero angle (tunneling flame spread) at the limiting 0.5 cm/s external air Bow, to 90 degrees (semicircular flame spread) for external Bows at and above 5 cm/s, and higher oxygen concentrations. The fan angle was shown to be directly related to the limiting air flow velocity. A surface energy balance reveals chat the heat feedback rate from the upstream flame to the surface decreases with decreasing oxygen mass transport via either imposed flow velocity or ambient oxygen concentration. Quenching extinction occurs when the heat feedback rate from the flame is no longer sufficient to offset the ongoing surface radiative heat losses. Despite the convective heating from the upstream flame. the downstream flame was inhibited due to the 'oxygen shadow' of the upstream flame for the air Bow conditions studied. Downstream flame spread rates in air, measured alter upstream flame spread was complete and extinguished, were slower than upstream flame spread rates at the same Bow. The quench regime for the transition to flame spread was skewed toward the downstream, because of the augmenting role of diffusion for opposed Bow flame spread, versus the canceling effect of diffusion at very low cocurrent flows. (C) 2001 by The Combustion Institute. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Hokkaido Univ, Div Mech Sci, Sapporo, Hokkaido 0608628, Japan. RP Olson, SL (reprint author), NASA, Glenn Res Ctr, Mail Stop 5003-115, Cleveland, OH 44135 USA. RI Fujita, Osamu/D-6797-2012 NR 18 TC 23 Z9 28 U1 1 U2 9 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 APR PY 2001 VL 125 IS 1-2 BP 852 EP 864 DI 10.1016/S0010-2180(00)00249-2 PG 13 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 427EB UT WOS:000168390900010 ER PT J AU Breaker, LC Liu, PC Torrence, C AF Breaker, LC Liu, PC Torrence, C TI Intraseasonal oscillations in sea surface temperature, wind stress, and sea level off the central California coast SO CONTINENTAL SHELF RESEARCH LA English DT Article DE wind stress; sea surface temperature; California coast ID 40-50 DAY OSCILLATION; ATMOSPHERIC ANGULAR-MOMENTUM; OUTGOING LONGWAVE RADIATION; NORTHERN HEMISPHERE WINTER; EQUATORIAL KELVIN WAVES; INDIAN-OCEAN; ZONAL WIND; PACIFIC; CURRENTS; CIRCULATION AB The wavelet transform is used to conduct spectral and cross-spectral analysis of daily time series of sea surface temperature (SST), surface wind stress, and sea level off the central California coast for an 18-year period from 1974 through 1991. The spectral band of primary interest is given by intraseasonal time scales ranging from 30 to 70 days. Using the wavelet transform, we examine the evolutionary behavior of the frequently observed 40-50 day oscillation originally discovered in the tropics by Madden and Julian, and explore the relative importance of atmospheric vs oceanic forcing for a range of periods where both could be important. Wavelet power spectra of each variable reveal the event-like, nonstationary nature of the intraseasonal band. Peaks in wavelet power typically last for 3-4 months and occur, on average, approximately once every 18 months. Thus, their occurrence and/or duration off central California is somewhat reduced in comparison to their presence in the tropics. Although peaks in wind stress often coincide with peaks in SST and/or sea level, no consistent relationships between the variables was initially apparent. The spectra suggest, however, that relationships between the variables, if and where they do exist, are event-dependent and thus have time scales of the same order. Cross-wavelet spectra between wind stress and SST indicate that periods of high coherence (> 0.90) occur on at least six occasions over the 18-year period of record. Phase differences tend to be positive, consistent with wind forcing. For wind stress vs sea level, the cross-wavelet spectra indicate that periods of high coherence, which tend to correlate with lags close to zero, also occur, but are less frequent. As with SST, the periods of high coherence usually coincide with events in the wavelet power spectra. The somewhat weaker relationship between wind stress and sea level may be due to an independent contribution to sea level through remote forcing by the ocean originating in the tropics. Finally, simple dynamical arguments regarding the lag relationships between the variables appear to be consistent with the cross-wavelet results. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Natl Ctr Environm Predict, Washington, DC 20233 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Natl Ctr Atmospher Res, Adv Study Program, Boulder, CO 80307 USA. RP Breaker, LC (reprint author), Natl Ctr Environm Predict, Washington, DC 20233 USA. NR 48 TC 13 Z9 13 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD APR-MAY PY 2001 VL 21 IS 6-7 BP 727 EP 750 DI 10.1016/S0278-4343(00)00080-7 PG 24 WC Oceanography SC Oceanography GA 420BT UT WOS:000167984600008 ER PT J AU Krueger, S AF Krueger, S TI Neutron reflection from interfaces with biological and biomimetic materials SO CURRENT OPINION IN COLLOID & INTERFACE SCIENCE LA English DT Review DE neutron reflectivity; model membranes; lipid bilayers; lipid monolayers; interfaces; self-assembly ID SPECULAR REFLECTION; PHOSPHOLIPID MONOLAYERS; LIPID BILAYERS; PHASE STATE; X-RAY; SURFACE; WATER; REFLECTOMETRY; MEMBRANE; GOLD AB During the past decade, neutron reflectivity has increasingly become an important technique for the characterization of biological and biomimetic thin films. Advancements in instrumentation, sample environment and measurement protocols now make it possible to obtain Angstrom-level information about the composition of these materials along the axis perpendicular to the plane of the membrane. A newly developed phase-sensitive neutron reflectivity technique now allows direct inversion of the reflectivity data to obtain unique compositional depth profiles of the films. This review concentrates on the development of these neutron reflectivity methods for the study of peptide and protein interactions with model membranes. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Krueger, S (reprint author), NIST, Ctr Neutron Res, 100 Bur Dr,Stop 8562, Gaithersburg, MD 20899 USA. NR 31 TC 52 Z9 54 U1 1 U2 14 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1359-0294 J9 CURR OPIN COLLOID IN JI Curr. Opin. Colloid Interface Sci. PD APR PY 2001 VL 6 IS 2 BP 111 EP 117 DI 10.1016/S1359-0294(01)00073-5 PG 7 WC Chemistry, Physical SC Chemistry GA 436CY UT WOS:000168920000005 ER PT J AU Cowen, JP Bertram, MA Wakeham, SG Thomson, RE Lavelle, JW Baker, ET Feely, RA AF Cowen, JP Bertram, MA Wakeham, SG Thomson, RE Lavelle, JW Baker, ET Feely, RA TI Ascending and descending particle flux from hydrothermal plumes at Endeavour Segment, Juan de Fuca Ridge SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article DE hydrothermal plumes; organic carbon production; ascending/descending flux; endeavour segment; Juan de Fuca Ridge ID PARTICULATE ORGANIC MATERIAL; SCATTERING LAYER; NORTH PACIFIC; METHANE OXIDATION; ABYSSAL WATERS; VENT FIELD; MATTER; OCEAN; MANGANESE; SYSTEM AB Bio-acoustic surveys and associated zooplankton net tows have documented anomalously high concentrations of zooplankton within a 100 m layer above the hydrothermal plumes at Endeavour Segment, Juan de Fuca Ridge. These and other data suggest that congregating epi-plume zooplankton are exploiting a food substrate associated with the hydrothermal plume. Ascending, organic-rich particles could provide a connection, Consequently, two paired sequentially sampling ascending and descending particle flux traps and a current meter were deployed on each of three moorings from July 1994 to May 1995. Mooring sites included an on-axis site (OAS; 47 degrees 57.0'N, 129 degrees 05.7'W) near the main Endeavour vent field, a "down-current" site 3 km west of the main vent field (WS), and a third background station 43 km northeast of the vent field (ES). Significant ascending and descending particle fluxes were measured at all sites and depths. Lipid analyses indicated that ascending POC was derived from mid-depth and deep zooplankton whereas descending POC also contained a component of photosynthetically derived products from the sea surface. Highest ascending POC fluxes were found at the hydrothermal plume-swept sites (OAS and WS). The limited data available, however, precludes an unequivocal conclusion that hydrothermal processes contribute to the ascending flux of organic carbon at each site. Highest ascending to descending POC flux ratios were also found at WS. Observed trends in POC, PMn/PTi, and PFe/PTi clearly support a hydrothermal component to the descending flux at the plume-swept WS site (no descending data was recovered at OAS) but not at the background ES site. Alternative explanations for ascending particle data are discussed. First-order calculations for the organic carbon input (5-22 mg C m(-2) d(-1)) required to sustain observed epi-plume zooplankton anomalies at Endeavour are comparable both to measured total POC flux to epi-plume depths (2-5 mg C m(-2) d(-1): combined hydrothermal and surface derived organic carbon) and to estimates of the total potential in situ organic carbon production (2-9 mg C m(-2) d(-1)) from microbial oxidation of hydrothermal plume H-2. CH4 and NH4+. (C) 2001 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. Skidaway Inst Oceanog, Savannah, GA 31411 USA. Fisheries & Oceans Canada, Inst Ocean Sci, Sidney, BC V8L 4B2, Canada. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Cowen, JP (reprint author), Univ Hawaii, Dept Oceanog, 1000 Pope Rd, Honolulu, HI 96822 USA. NR 75 TC 27 Z9 27 U1 0 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD APR PY 2001 VL 48 IS 4 BP 1093 EP 1120 DI 10.1016/S0967-0637(00)00070-4 PG 28 WC Oceanography SC Oceanography GA 403TL UT WOS:000167058500006 ER PT J AU Moffat, TP Wheeler, D Huber, WH Josell, D AF Moffat, TP Wheeler, D Huber, WH Josell, D TI Superconformal electrodeposition of copper SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID ADSORPTION; TRENCHES; VIAS AB A model of superconformal electrodeposition is presented based on a local growth velocity that is proportional to coverage of a catalytic species at the metal/electrolyte interface. The catalyst accumulates at the interface through reaction with the electrolyte. More importantly, if the concentration of the catalyst precursor in the electrolyte is dilute, then surface coverage within small features can change far more rapidly due to changing interface area. In such a case, the catalyst effectively floats on the interface during deposition, with changes in coverage coupled to alterations in arc-length of the moving surface. The local coverage therefore increases during conformal growth on a concave surface, resulting in a corresponding increase in the local deposition rate. The opposite is true for a convex surface. The model is supported by experiments and simulations of superconformal copper deposition in 350-100 nm wide features. The model also has significant implications for understanding the influence of adsorbates on the evolution of surface roughness during electrodeposition. (C) 2001 The Electrochemical Society. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. RP Moffat, TP (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Wheeler, Daniel/C-8994-2009 OI Wheeler, Daniel/0000-0002-2653-7418 NR 14 TC 222 Z9 223 U1 5 U2 52 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD APR PY 2001 VL 4 IS 4 BP C26 EP C29 DI 10.1149/1.1354496 PG 4 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 408VC UT WOS:000167347300010 ER PT J AU Berger, JR Tewary, VK AF Berger, JR Tewary, VK TI Greens functions for boundary element analysis of anisotropic bimaterials SO ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS LA English DT Article DE anisotropic elasticity; Greens functions; fundamental solutions; boundary element methods ID FUNDAMENTAL-SOLUTIONS; INTERFACE CRACKS AB We present several Greens functions for anisotropic bimaterials for two-dimensional elasticity and steady-state heat transfer problems. The details of the various Greens functions for perfect, slipping, and cracked interfaces are given for mechanical loading conditions, previously reported formulations for cubic materials are extended to materials with general anisotropy in which plane strain deformations can exist. Wt also give the steady-state Greens function for thermal loading of a bimaterial with a perfectly bonded interface. The Greens functions are incorporated in boundary integral formulations and method of fundamental solutions formulations for analysis of finite solids under general boundary conditions. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Colorado Sch Mines, Div Engn, Golden, CO 80401 USA. Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Berger, JR (reprint author), Colorado Sch Mines, Div Engn, Golden, CO 80401 USA. RI Berger, John/F-5169-2010 NR 26 TC 24 Z9 24 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-7997 J9 ENG ANAL BOUND ELEM JI Eng. Anal. Bound. Elem. PD APR-MAY PY 2001 VL 25 IS 4-5 BP 279 EP 288 DI 10.1016/S0955-7997(01)00023-6 PG 10 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 440RT UT WOS:000169188600007 ER PT J AU Kimm-Brinson, KL Ramsdell, JS AF Kimm-Brinson, KL Ramsdell, JS TI The red tide toxin, brevetoxin, induces embryo toxicity and developmental abnormalities SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE brevetoxin; red tides; teratogenicity ID SENSITIVE SODIUM-CHANNELS; PTYCHODISCUS-BREVIS; GYMNODINIUM-BREVE; DINOFLAGELLATE; CIGUATOXINS AB Brevetoxins are lipophilic polyether toxins produced by the red tide dinoflagellate Gymnodinium breve, and their neurotoxic effects on adult animals have been documented. In this study, we characterized adverse developmental effects of brevetoxin-1 (PbTx-1) using an exposure: paradigm that parallels the maternal oocyte transfer of toxin. Medaka fish (Oryzias latipes) embryos mere exposed to PbTx-1 via microinjection of toxin reconstituted in a triolein oil droplet. Embryos microinjected with doses of 0.1-8.0 ng/egg (ppm) of brevetoxin-l exhibited pronounced muscular activity (hyperkinesis) after embryonic day 4. Upon hatching, morphologic abnormalities were commonly found in embryos at the following lowest adverse effect levels: 1.0-3.0 ppm, lateral curvature of the spinal column; 3.1-3.4 ppm, herniation of brain meninges through defects in the skull; and 3.4-4.0 ppm, malpositioned eye. Hatching abnormalities were also commonly observed at brevetoxin doses of 2.0 ppm and higher with head-first, as opposed to the normal tail-first, hatching, and doses > 4.1 ng/egg produced embryos that developed but failed to hatch. Given the similarity of developmental professes found between higher and lower vertebrates, teratogenic effects of brevetoxins have the potential to occur among different phylogenetic classes. The observation of developmental abnormalities after PbTx-1 exposure identifies a new spectrum of adverse effects that may be expected to occur following exposure to G. breve red tide events. C1 NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Marine Biotoxins Program, Charleston, SC 29412 USA. RP Ramsdell, JS (reprint author), NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Coastal Res Branch, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 35 TC 32 Z9 35 U1 4 U2 11 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD APR PY 2001 VL 109 IS 4 BP 377 EP 381 DI 10.2307/3454897 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 427NZ UT WOS:000168413600028 PM 11335186 ER PT J AU Tatara, CP Newman, MC Mulvey, M AF Tatara, CP Newman, MC Mulvey, M TI Effect of mercury and Gpi-2 genotype on standard metabolic rate of eastern mosquitofish (Gambusia holbrooki) SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE Gambusia holbrooki; standard metabolic rate; genetics; mercury ID KREBS CYCLE METABOLITES; ALLOZYME GENOTYPE; DEMOGRAPHIC RESPONSES; INORGANIC MERCURY; AFFINIS BAIRD; GIRARD 1859; POPULATIONS; EXPOSURE; SUSCEPTIBILITY; VERIFICATION AB Previous studies demonstrated differential mortality among mosquitofish of different Gpi-2 genotypes during acute mercury and arsenate exposures. Mercury-exposed mosquitofish also had Gpi-2 genotype-specific differences in glycolytic and Krebs. cycle metabolite pools. The mortality and metabolite data suggested that mosquitofish bearing specific Gpi-2 genotypes might differ in metabolic efficiency. with less efficient Gpi-2 genotypes having higher standard metabolic rates (SMRs) and shorter times to death during acute mercury exposure. Effect of Gpi-2 genotype on SMR was assessed with a factorial arrangement of six Gpi-2 genotypes and two exposure sequences (Control - Control; Control - 100 mug/L Hg). The SMRs were estimated by measuring oxygen consumption using an indirect, closed-circuit, computer-controlled respirometer A 48-h exposure to 100 mug/L of mercury resulted in a 16.7% elevation of SMR above control levels (p = 0.001). The Gpi-2 genotype and the number of heterozygous loci per individual had no significant effect on SMR in mercury-exposed mosquitofish. The experimental results do not support the hypothesis that Gpi-2 genotype-specific differences in glycolytic and Krebs cycle metabolite pools and mortality in mosquitofish exposed to mercury are associated with differences in SMR. C1 Natl Marine Fisheries Serv, Santa Rosa, CA 95404 USA. Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. RP Tatara, CP (reprint author), Natl Marine Fisheries Serv, SW Reg,777 Sonoma Ave,Suite 325, Santa Rosa, CA 95404 USA. NR 30 TC 16 Z9 16 U1 3 U2 10 PU SETAC PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3367 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD APR PY 2001 VL 20 IS 4 BP 782 EP 786 PG 5 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 457YJ UT WOS:000170165700013 PM 11345454 ER PT J AU Lotufo, GR Landrum, PF Gedeon, ML AF Lotufo, GR Landrum, PF Gedeon, ML TI Toxicity and bioaccumulation of DDT in freshwater amphipods in exposures to spiked sediments SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE dichlorodiphenyltrichloroethane; sediment; amphipods; equilibrium partitioning; critical body residue ID POLYCHAETE NEANTHES ARENACEODENTATA; EQUILIBRIUM-PARTITIONING THEORY; SAN-FRANCISCO BAY; HYALELLA-AZTECA; ORGANIC CONTAMINANTS; PONTOPOREIA-HOYI; WATER AMPHIPODS; LAKE-MICHIGAN; TOXICOKINETICS; FLUORANTHENE AB The amphipods Hyalella azteca and Diporeia spp. were exposed to sediments dosed with dichlorodiphenyltrichloroethane (DDT), and the toxicity and toxicokinetics were determined. The toxicity was evaluated with the equilibrium partitioning (EqP) and critical body residue approaches. The DDT in the sediments degraded during the equilibration period prior to organism exposure. Thus, the toxicity using EqP pore-water toxic units (TUs) was evaluated for DDT and its degradation product, dichlorodiphenyldichloroethane (DDD), as the ratio of the predicted interstitial water concentration divided by the water-only LC50 values. The sum of TUs (Sigma TU) was assumed to best represent the toxicity of the mixture. For H. azteca, the 10-d LC50 was 0.98 and 0.33 :ETU for two experiments. For Diporeia spp., no toxicity was found in the first experiment with up to 3 Sigma TU predicted in the interstitial water. However, in the second experiment, the 28-d LC50 was 0.67 ITU. These data suggest that the EqP approach approximately predicts the toxicity for the combination of DDT and DDD in sediment, provided a toxic unit approach is employed. The critical body residue approach also used TU's because DDT is biotransformed by H. azteca and because of the dual exposure to DDT and DDD. Because biotransformation was only determined in the second experiment, the critical body residue approach could only be evaluated for that case. The TUs were calculated as the ratio of the concentration in the live amphipods divided by the respective LR50 (residue concentration required to produce 50% mortality) values. The LR50 was 1.1 Sigma TU for H. azteca for the 10-d exposure and 0.53 for Diporeia spp. after a 28-d exposure. Thus, this approach was also quite successful in predicting the toxicity. The accumulation and loss rates for H. azteca were much greater than for Diporeia spp. Thus, 10-d exposures represent steady-state conditions for H. azteca, while even at 28-d, the Diporeia spp. are not at steady state. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Cooperat Inst Limnol & Ecosyst Res, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Michigan, 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 38 TC 27 Z9 29 U1 2 U2 12 PU SETAC PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3367 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD APR PY 2001 VL 20 IS 4 BP 810 EP 825 DI 10.1897/1551-5028(2001)020<0810:TABODI>2.0.CO;2 PG 16 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 457YJ UT WOS:000170165700017 PM 11345458 ER PT J AU Castellanos, DL Rozas, LP AF Castellanos, DL Rozas, LP TI Nekton use of submerged aquatic vegetation, marsh, and shallow unvegetated bottom in the Atchafalaya River Delta, a Louisiana tidal freshwater ecosystem SO ESTUARIES LA English DT Article ID LOWER CHESAPEAKE BAY; CALLINECTES-SAPIDUS RATHBUN; ZOSTERA-MARINA MEADOWS; SALT-MARSH; SEAGRASS MEADOWS; FISH COMMUNITIES; SAMPLING CHARACTERISTICS; STRUCTURAL COMPONENTS; HABITAT COMPLEXITY; ABUNDANCE AB We sampled nekton (fishes and decapod crustaceans) in submerged aquatic vegetation (SAV) (Potamogeton nodosus, Najas guadalupensis), in emergent marsh vegetation (Sagittaria spp. and Scirpus americanus), and over unvegetated bottom associated with three islands in the Atchafalaya River Delta, Louisiana. The purpose of our study was to quantify nekton densities in these major aquatic habitat types and to document the relative importance of these areas to numerically dominant aquatic organisms. We collected a total of 33 species of fishes and 7 species of crustaceans in 298 1-m(2) throw trap samples taken over three seasons: summer (July and August 1994), fall (September and October 1994), and spring (May and June 1995). Fishes numerically accounted for > 65% of the total organisms collected. Vegetated areas generally supported much higher nekton densities than unvegetated sites, although bay anchovies Anchoa mitchilli were more abundant over unvegetated bottom than in most vegetated habitat types. Among vegetation types, most species showed no apparent preference between SAV and marsh. However, inland silversides Menidia beryllina and freshwater gobies Gobionellus shufeldti were most abundant in Scirpus marsh in summer, and blue crabs Callinectes sapidus were most abundant in SAV (Potamogeton) in spring. Several species (sheepshead minnow Cyprinodon variegatus, rainwater killifish Lucania parva, and blue crab) apparently selected the vegetated backmarsh of islands (opposite of riverside) over streamside Scirpus marsh. Freshwater gobies, in contrast, were most abundant in streamside Scirpus marsh. Densities of juvenile blue crabs were high (up to 17 m(-2)) in vegetated delta habitat types and comparable to values reported from more saline regions of Gulf Coast estuaries. Shallow vegetated habitat types of the Atchafalaya River Delta and other tidal freshwater systems of the Gulf Coast may be: important nursery areas for blue crabs and other estuarine species. C1 Univ Louisiana Lafayette, Dept Biol, Lafayette, LA 70504 USA. NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Fishery Ecol Branch,Galveston Lab, Galveston, TX 77551 USA. RP Castellanos, DL (reprint author), Louisiana Dept Nat Resources, Coastal Restorat Div, POB 639, Abbeville, LA 70511 USA. NR 65 TC 40 Z9 41 U1 1 U2 17 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD APR PY 2001 VL 24 IS 2 BP 184 EP 197 DI 10.2307/1352943 PG 14 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 438KR UT WOS:000169052900004 ER PT J AU Colborn, J Crabtree, RE Shaklee, JB Pfeiler, E Bowen, BW AF Colborn, J Crabtree, RE Shaklee, JB Pfeiler, E Bowen, BW TI The evolutionary enigma of bonefishes (Albula spp.): Cryptic species and ancient separations in a globally distributed shorefish SO EVOLUTION LA English DT Review DE cytochrome b; leptocephalus; marine fish; mitochondrial DNA; phylogeography; speciation; stabilizing selection; sympatry ID INDO-WEST PACIFIC; MITOCHONDRIAL-DNA EVOLUTION; GENETIC-STRUCTURE; OCEAN CURRENTS; MARINE FISHES; FLORIDA-KEYS; POPULATION-GENETICS; SEA-URCHINS; REEF FISHES; SPECIATION AB Many examples of cryptic marine species have been demonstrated with biochemical and molecular studies. In most cases, a broadly distributed taxon is actually a group of sibling species that can be distinguished (upon closer examination) by ecological or morphological characters. Fishes of the family Albulidae constitute a notable exception. Bonefish (Albula spp.) morphology and ecology are highly conserved around the globe, and their extended pelagic larval stage could allow population connections on a vast geographic scale. Based on this perceived homogeneity, bonefishes were classified as a single pantropical species, A. vulpes. However, allozyme studies of Hawaiian populations indicated that two sympatric species (A. glossodonta and A. neoguinaica) are included in the synonymy of A. vulpes. To ascertain the number and distribution of evolutionary partitions in Albula, we surveyed 564 bp of mitochondrial DNA (mtDNA) cytochrome b from 174 individuals collected at 26 locations. Sequence comparisons reveal eight deep lineages (d = 5.56-30.6%) and significant population structure within three of the four lineages that could be tested (phi (ST) = 0.047-0.678). These findings confirm the genetic distinctiveness of the three species noted above and invoke the possibility of five additional species. Clock estimates for mtDNA indicate that these putative species arose 4-20 million years ago. Distinct evolutionary lineages coexist in several sample locations, yet show little morphological or ecological differentiation in sympatry. Thus, bonefish species seem to defy the evolutionary conventions of morphological differentiation over time and ecological displacement in sympatry. Despite multiple cases of sympatry, sister-taxa relationships inferred from mtDNA indicate that divergence in allopatry has been the predominant speciation mechanism in Albula. Stabilizing selection in the homogeneous habitat occupied by bonefishes (tropical sand flats) could promote the retention of highly conserved morphology and ecology. C1 Univ Florida, Dept Fisheries & Aquat Sci, Gainesville, FL 32653 USA. Natl Marine Fisheries Serv, SE Reg Ctr, St Petersburg, FL 33702 USA. Washington Dept Fish & Wildlife, Olympia, WA 98501 USA. Arizona State Univ, Dept Biol, Tempe, AZ 85287 USA. RP Univ Florida, Dept Fisheries & Aquat Sci, Gainesville, FL 32653 USA. EM bowen@gnv.ifas.ufl.edu NR 113 TC 144 Z9 157 U1 2 U2 29 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0014-3820 EI 1558-5646 J9 EVOLUTION JI Evolution PD APR PY 2001 VL 55 IS 4 BP 807 EP 820 DI 10.1554/0014-3820(2001)055[0807:TEEOBA]2.0.CO;2 PG 14 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 434WA UT WOS:000168837800017 PM 11392398 ER PT J AU Baumgartner, MF Mullin, KD May, LN Leming, TD AF Baumgartner, MF Mullin, KD May, LN Leming, TD TI Cetacean habitats in the northern Gulf of Mexico SO FISHERY BULLETIN LA English DT Article ID NORTHEASTERN UNITED-STATES; SPERM WHALE DISTRIBUTIONS; DOLPHIN GRAMPUS-GRISEUS; WARM-CORE RING; OF-MEXICO; CALIFORNIA WATERS; CONTINENTAL-SLOPE; TROPICAL PACIFIC; WESTERN GULF; LOOP CURRENT AB Surveys were conducted in the northern Gulf of Mexico during the spring seasons of 1992, 1993, and 1994 to determine the distribution, abundance, and habitat preferences of oceanic cetaceans. The distributions of bottlenose dolphins (Tsursiops truncatus), Risso's dolphins (Grampus griseus) Kogia spp. (pygmy [kogia breviceps] and dwarf sperm whales [Kogia sima]) pantropical spotted dolphins (Stenella attenuata), and sperm whales (Physeter macrocephalus) were examined with respect to depth. depth gradient, surface temperature, surface temperature variability the depth of the 15 degreesC isotherm, surface chlorophyll concentration, and epipelagic zooplankton biomass. Bottlenose dolphins were encountered in two distinct legions: the shallow continental shelf (0-150 mi and just seaward of the shelf break (200-760 mi. Within both of these depth strata, bottlenose dolphins were sighted more frequently than expected in regions of high surface temperature variability which suggests an association with ocean fronts. Risso's dolphins were encountered over the steeper sections of the upper continental slope (200-1000 m), whereas the Kogia spp. were sighted more frequently in waters of the upper continental slope that had high zooplankton biomass. The pantropical spotted dolphin and sperm whales were similarly distributed over the lower continental slope and deep Gulf (>1000 m), but sperm whales were generally absent from anticyclonic oceanographic features (e.g. the Loop Current. warm-core eddies) characterized by deep occurrences of the 15 degreesC isotherm. Habitat partitioning, high-use areas, species accounts, environmental sampling limitations, and directions for future habitat work in the Gulf of Mexico are discussed. C1 Natl Marine Fisheries Serv, SE Fisheries Ctr, Mississippi State, MS 39529 USA. John C Stennis Space Ctr, Mississippi State, MS 39529 USA. RP Baumgartner, MF (reprint author), Oregon State Univ, Ctr Ocean & Atmosper Sci, 104 Ocean Adm Bldg, Corvallis, OR 97331 USA. NR 68 TC 63 Z9 74 U1 1 U2 8 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 2001 VL 99 IS 2 BP 219 EP 239 PG 21 WC Fisheries SC Fisheries GA 429ET UT WOS:000168503600001 ER PT J AU Bjorndal, KA Bolten, AB Koike, B Schroeder, BA Shaver, DJ Teas, WG Witzell, WN AF Bjorndal, KA Bolten, AB Koike, B Schroeder, BA Shaver, DJ Teas, WG Witzell, WN TI Somatic growth function for immature loggerhead sea turtles, Caretta caretta, in southeastern US waters SO FISHERY BULLETIN LA English DT Article ID LENGTH-FREQUENCY ANALYSIS; GREAT-BARRIER-REEF; CHELONIA-MYDAS; POLYPHASIC GROWTH; GREEN TURTLES; RATES; AGE; MULTIFAN; MODEL; POPULATIONS AB The Sea Turtle Stranding and Salvage Network, coordinated by the National Marine Fisheries Service through a network of state coordinators. archives data on sea turtles that strand along the U.S. coast. We conducted length-frequency analyses, using MUL-TIFAN software, to generate somatic growth functions for loggerhead sea turtles, Caretta caretta, that stranded along the Atlantic coast of Florida (n=1234) and along the U.S. coast of the Gulf of Mexico (n=570) between 1988 and 1995. In both legions, the size range of loggerhead sea turtles between the size at which they begin to recruit in substantial numbers from pelagic to neritic habitats (46 fm curved carapace length [CCL]) and minimum size at sexual maturity (87 cm CCL) was composed of 20 year classes and had similar von Bertalanffy growth functions. Our estimates of 20 ear classes fall within the range of estimates calculated from previous studies (9 to 29 years) for this life stage. Because sun survivorship in this size range has been identified as critical for population recovery an accurate estimate of life stage is essential far developing effective management plans. C1 Univ Florida, Archie Carr Ctr Sea Turtle Res, Dept Zool, Gainesville, FL 32611 USA. Aquarium Americas, New Orleans, LA 70130 USA. NOAA, Natl Marine Fisheries Serv, Off Protected Resources, Silver Spring, MD 20910 USA. US Geol Survey, Padre Isl Natl Seashore, Biol Resources Div, Corpus Christi, TX 78480 USA. NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Miami, FL 33149 USA. RP Bjorndal, KA (reprint author), Univ Florida, Archie Carr Ctr Sea Turtle Res, Dept Zool, POB 118525, Gainesville, FL 32611 USA. OI Bjorndal, Karen/0000-0002-6286-1901 NR 34 TC 35 Z9 38 U1 1 U2 6 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 2001 VL 99 IS 2 BP 240 EP 246 PG 7 WC Fisheries SC Fisheries GA 429ET UT WOS:000168503600002 ER PT J AU Burton, ML AF Burton, ML TI Age, growth, and mortality of gray snapper, Lutjanus griseus, from the east coast of Florida SO FISHERY BULLETIN LA English DT Article ID SOUTHEASTERN UNITED-STATES; SOUTH-ATLANTIC BIGHT; VERMILION SNAPPER; NORTH-CAROLINA; LIFE-HISTORY; REEF FISHES; PARAMETERS; BIOLOGY; SIZE AB Gray snapper, Lutjanus griseus, were sampled from recreational headboat and commercial landings along the east coast of Florida, 1994-97. Fish were weighed (g) and measured (total Length, Ttl in nlm): and sagittal otoliths were removed for aging. Marginal increment analysis on sectioned otoliths (n=1243) confirmed annulus formation in June and July: The oldest fish examined was 24 years old and measured 760 mm TL. Weight-length relations were not significantly different by sex. Weight-length relations were significantly different (F=39.198. P < 0.001, df=10,705) for fish measured from the headboat survey from 1982-97 between north Florida (W=8.4 x 10(-9) x TL3.08, n=4034) and south Florida (W=5.45 x 10(-9) x TL3 15, n=6670), where W = total weight (kg). The TL-otolith radius (OR) relationships were described by the following equations: TL = (10.02 x OR) - 52.98 (r(2) = 0.90, n=519, north Florida), and TL = (9.90 x OR)- 91.68 (r(2) = 0.78, n=724, south Florida). Mean lengths at age from back-calculations to the last annulus ranged from 121 mm at the end of age 1 to 740 mm at age 24 for north Florida, and 227 mm at age 2 to 495 mm at age 15 For south Florida. The von Bertalanffy growth equations were L-t = 717 x (1-e ' (-0.17 mu + 0.025 eta)) for north Florida and L-t = 625 x (1 - e ' (-0.13 mu + 1.33 eta)) for south Florida. Estimates of M ranged from 0.14 to 0.43 for north Florida and from 0.29 to 0.38 for south Florida. Estimates of Z averaged 0.34 for north Florida and 0.95 for south Florida. Recruitment to the fisheries occurred between ages 5 and 8 for north Florida and ages 4 and 5 for south Florida. Estimates off for gray snapper by area were 0.16 for north Florida and 0.66 for south Florida. C1 NOAA, Natl Marine Fisheries Serv, Cent Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. RP Burton, ML (reprint author), NOAA, Natl Marine Fisheries Serv, Cent Coastal Fisheries & Habitat Res, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. EM Michael.Burton@noaa.gov NR 34 TC 34 Z9 36 U1 2 U2 8 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 EI 1937-4518 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 2001 VL 99 IS 2 BP 254 EP 265 PG 12 WC Fisheries SC Fisheries GA 429ET UT WOS:000168503600004 ER PT J AU Hobson, ES Chess, JR Howard, DF AF Hobson, ES Chess, JR Howard, DF TI Interannual variation in predation on first-year Sebastes spp. by three northern California predators SO FISHERY BULLETIN LA English DT Article ID DENSITY-DEPENDENT MORTALITY; POPULATION REGULATION; JUVENILE MORTALITY; TEMPERATE REEF; FISH; RECRUITMENT; ROCKFISHES; SETTLEMENT; LARVAL; SCORPAENIDAE AB There is much interannual variation in numbers of first-year Sebastes that settle near shore off northern California, and when more abundant, they become prey of an increased variety of predators. hmong predators that concentrate on these abundances are the black rockfish (Sebastes melanops); the blue rockfish (Sebastes mystinus); and the kelp greenling (Hexagrammos decagrammus). One might expect S. melanops to be involved in these attacks because it is known to be piscivorous, hut S. mystinus and H. decagrammus ordinarily feed on on invertebrates. The predation on Sebastes juveniles is concentrated during a relatively brief period shortly after they have settled in nearshore habitats. Most of this predation occurs during June and decreases sharply through July and August, and relatively little after that. me argue that the pattern of predation reflects removal of less adapted individuals during the period shortly after settlement. C1 SW Fisheries Sci Ctr, Santa Curz Lab, Santa Cruz, CA 95060 USA. Gulf Farllones Natl Marine Sanctuary, San Francisco, CA 94123 USA. RP Hobson, ES (reprint author), SW Fisheries Sci Ctr, Santa Curz Lab, 110 Shaffer Rd, Santa Cruz, CA 95060 USA. NR 33 TC 21 Z9 21 U1 0 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 2001 VL 99 IS 2 BP 292 EP 302 PG 11 WC Fisheries SC Fisheries GA 429ET UT WOS:000168503600007 ER PT J AU Jacobson, LD Brodziak, J Rogers, J AF Jacobson, LD Brodziak, J Rogers, J TI Depth distributions and time-varying bottom trawl selectivities for Dover sole (Microstomus pacificus), sablefish (Anoplopoma fimbria), and thornyheads (Sebastolobus alascanus and S-altivelis) in a commercial fishery SO FISHERY BULLETIN LA English DT Article ID SAMPLING TRAWL; CATCH; GROUNDFISH AB We estimated size-specific depth distributions and commercial bottom trawl fishery selectivities for Dover sole (Microstomus pacificus), shortspine thornyhead (Sebastolobus alascanus), longspine thornyhead (S. altivelis), and sablefish (Anoplopoma fimbria) along the U.S, west coast. Depth distributions are size-specific because fish migrate ontogenetically to deep water: With ontogenetic migration, fishery selectivities of commercial bottom trawls depend on depth of fishing because large fish ale most common in deep water. Depth distributions were similar for northern and southern areas and for males and females. Results show ontogenetic migration in sablefish, suggest a possible weak ontogenetic migration in longspine thornyhead, and confirm ontogenetic migration patterns already reported for Dover sole and shortspine thornyhead. Fishery selectivities varied among species, between areas, and changed dramatically over time for most species as fishing effort moved into deep water: Our approach used biological data collected during research bottom trawl surveys but was generally not affected by size selectivity of bottom trawl survey gear. Uncertainty in our commercial bottom trawl selectivity estimates was mostly from length-specific capture probabilities (or vulnerabilities) for fish in the path of commercial bottom trawls. Our estimates complement selectivity estimates fi om stock assessment models. The approach may be useful whenever the geographic distribution of fish depends on size ol age, fishing effort is not randomly distributed geographically, and sun ey estimates of fish density, bathymetric data, and commercial fishing effort information ar e available. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Newport, OR 97365 USA. RP Jacobson, LD (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 37 TC 16 Z9 16 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 2001 VL 99 IS 2 BP 309 EP 327 PG 19 WC Fisheries SC Fisheries GA 429ET UT WOS:000168503600009 ER PT J AU Zimmermann, M Harrison, RC Jones, AF AF Zimmermann, M Harrison, RC Jones, AF TI Differential parasitism by Naobranchia occidentalis (Copepoda : Naobranchiidae) and Nectobrachia indivisa (Copepoda : Lernaeopodidae) on northern rock sole (Lepidopsetta polyxystra Orr and Matarese, 2000) and southern rock sole (L-bilineata Ayres, 1855) in Alaskan waters SO FISHERY BULLETIN LA English DT Article ID TOADFISH TETRACTENOS-HAMILTONI; VARIABILIS COPEPODA; PARASITOLOGY; TERMS; GILL AB Northern rock sole (Lepidopsetta polyxystra Orr and Matarese, 2000) and southern rock sole it. bilineata Ayres, 1855) from the Gulf of Alaska and northern rock sole from the Aleutian Islands were examined for gill parasites. Four species of copepod parasites were identified: Naobranchia occidentalis and Nectobrachia indivisa were the most common. Both parasites were more prevalent on northern lock sole (22% and 15%, respectively) than on southern rock sole (5% and 1%, respectively) in the Gulf of Alaska samples. Northern rock sole tended to have a greater mean intensity of Naobranchia occidentalis than southern rock sole but there was not a significant difference because of the high variance about the means; too few southern rock sole were infested by Nectobrachia indivisa for comparison. Northern rock sole from the Aleutian Islands region had a significantly greater prevalence (36%) and mean intensity (10.2/infested fish) of Naobranchia occidentalis than northern rock sole from the Gulf of Alaska (22%, and 4.4, respectively) but did not differ significantly in prevalence and mean intensity of Nectobrachia indivisa. Parasitized male northern rock sole from the Gulf of Alaska had a significantly reduced weight at length, indicating a possible Effect of parasitism. Naobranchia occidentalis selectively infested larger northern rock sole and only the largest southern rock sole. Nectobrachia indivisa also were found on larger northern rock sole but did not infest enough southern rock sole to describe a trend. Southern rock sole males were not infested by either parasite. Naobranchia occidentalis preferred to infest the middle gill arches of hosts and Nectobrachia indivisa preferred to infest the exterior gill arches of hosts. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Zimmermann, M (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 18 TC 2 Z9 4 U1 0 U2 4 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 2001 VL 99 IS 2 BP 371 EP 380 PG 10 WC Fisheries SC Fisheries GA 429ET UT WOS:000168503600015 ER PT J AU Dizdaroglu, M Jaruga, P Rodriguez, H AF Dizdaroglu, M Jaruga, P Rodriguez, H TI Identification and quantification of 8,5 '-cycle-2 '-deoxyadenosine in DNA by liquid chromatography/mass spectrometry SO FREE RADICAL BIOLOGY AND MEDICINE LA English DT Article DE -8,5 '-cyclo-purine nucleosides; mass spectrometry; nucleotide-excision repair; oxidative DNA damage; free radicals ID IRRADIATED NUCLEIC-ACIDS; IONIZATION MASS-SPECTROMETRY; RADICAL-INDUCED FORMATION; GAMMA-IRRADIATION; INTRAMOLECULAR CYCLIZATION; DEOXYRIBONUCLEIC-ACID; ENZYMATIC-HYDROLYSIS; AQUEOUS-SOLUTION; EXCISION-REPAIR; INDUCED DAMAGE AB Recent studies suggested that 8,5'-cyclo-2' -deoxyadenosine may play a role in diseases with defective nucleotide-excision repair. This compound is one of the major lesions, which is formed in DNA by hydroxyl radical attack on the sugar moiety of 2'-deoxyadenosine. It is likely to be repaired by nucleotide-excision repair rather than by base-excision repair because of a covalent bond between the sugar and base moieties. We studied the measurement of 8,5'-cyclo-2'-deoxyadenosine in DNA by liquid chromatography/isotope-dilution mass spectrometry. A methodology was developed for the analysis of 8,5'-cyclo-2'-deoxyadenosine by liquid chromatography in DNA hydrolyzed to nucleosides by a combination of four enzymes, i.e., DNase I, phosphodiesterases I and II, and alkaline phosphatase. Detection by mass spectrometry was performed using atmospheric pressure ionization-electrospray process in the positive ionization mode. Results showed that liquid chromatography/isotope-dilution mass spectrometry is well suited for identification and quantification of 8,5'-cyclo-2'-deoxyadenosine in DNA. Both (5'R)- and (5'S)-diastereomers of 8,5'-cyclo-2'-deoxyadenosine were detected. The level of sensitivity of liquid chromatography/mass spectrometry with selected-ion monitoring amounted to 2 fmol of this compound on the column. The yield of 8,5'-cyclo-2'-deoxyadenosine was measured in DNA in aqueous solution exposed to ionizing radiation at doses from 2.5 to 80 Gray. Gas chromatography/mass spectrometry was also used to measure this compound in DNA. Both techniques yielded similar results. The yield of 8,5'-cyclo-2'-deoxyadenosine was comparable to the yields of some of the other major modified bases in DNA, which were measured using gas chromatography/mass spectrometry. The measurement of 8,5'-cyclo-2'-deoxyadenosine by Liquid chromatography/mass spectrometry may contribute to the understanding of its biological properties and its role in diseases with defective nucleotide-excision repair. (C) 2001 Elsevier Science Inc. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Ludwik Rydygier Med Univ, Dept Clin Biochem, Bydgoszcz, Poland. RP Dizdaroglu, M (reprint author), NIST, Chem Sci & Technol Lab, Bldg 227-A243,Mail Stop 8311, Gaithersburg, MD 20899 USA. RI Jaruga, Pawel/M-4378-2015 NR 40 TC 68 Z9 68 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0891-5849 J9 FREE RADICAL BIO MED JI Free Radic. Biol. Med. PD APR 1 PY 2001 VL 30 IS 7 BP 774 EP 784 DI 10.1016/S0891-5849(01)00464-6 PG 11 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 415MD UT WOS:000167724600008 PM 11275477 ER PT J AU Nielsen, R Mattila, DK Clapham, PJ Palsboll, PJ AF Nielsen, R Mattila, DK Clapham, PJ Palsboll, PJ TI Statistical approaches to paternity analysis in natural populations and applications to the North Atlantic humpback whale SO GENETICS LA English DT Article ID MEGAPTERA-NOVAEANGLIAE; CHAMAELIRIUM-LUTEUM; MICROSATELLITE LOCI; COMPETITIVE GROUPS; LILIACEAE; BAY AB We present a new method for paternity analysis in natural populations that is based on genotypic data that can take the sampling fi action of putative parents into account. The method allows paternity assignment to be performed in a decision theoretic framework. Simulations at e performed to evaluate the utility and robustness of the method and to assess how many loci are necessary for reliable paternity: inference. In addition we present a method for testing hypotheses regarding relative reproductive success of different ecologically or behaviorally defined groups as well as a new method for estimating the current population size of males From genotypic data. This method is an extension of the Fractional paternity method to the case where only a proportion of all putative fathers hav e been sampled. It can also be applied to provide abundance estimates of the number of breeding males from genetic data. Throughout, the methods were applied to genotypic data collected from North Atlantic humpback whales (Megaptera novaeangliae) to test if the males that appear dominant during the mating season have a higher reproductive success than the subdominant males. C1 Cornell Univ, Dept Biometr, Ithaca, NY 14853 USA. Harvard Univ, Dept Organism & Evolutionary Biol, Cambridge, MA 02138 USA. Ctr Coastal Studies, Provincetown, MA 02567 USA. NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. Univ Wales, Sch Biol Sci, Bangor LL57 2UW, Gwynedd, Wales. RP Nielsen, R (reprint author), Cornell Univ, Dept Biometr, 439 Warren Hall, Ithaca, NY 14853 USA. EM rn28@cornell.edu RI Nielsen, Rasmus/D-4405-2009; Palsboll, Per /G-6988-2011 OI Nielsen, Rasmus/0000-0003-0513-6591; Palsboll, Per /0000-0002-4198-7599 NR 29 TC 87 Z9 91 U1 2 U2 24 PU GENETICS SOCIETY AMERICA PI BETHESDA PA 9650 ROCKVILLE AVE, BETHESDA, MD 20814 USA SN 0016-6731 EI 1943-2631 J9 GENETICS JI Genetics PD APR PY 2001 VL 157 IS 4 BP 1673 EP 1682 PG 10 WC Genetics & Heredity SC Genetics & Heredity GA 424GD UT WOS:000168223400025 PM 11290722 ER PT J AU Bosch, H Camy-Peyret, C Chipperfield, M Fitzenberger, R Harder, H Schiller, C Schneider, M Trautmann, T Pfeilsticker, K AF Bosch, H Camy-Peyret, C Chipperfield, M Fitzenberger, R Harder, H Schiller, C Schneider, M Trautmann, T Pfeilsticker, K TI Comparison of measured and modeled stratospheric UV/visible actinic fluxes at large solar zenith angles SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OZONE LOSS; SIMULATIONS; PHOTOLYSIS; ATMOSPHERE; NO2 AB Measured and modeled stratospheric filter sensitivity weighted ultraviolet/visible (UV/vis) actinic fluxes - approximating the NO2 photolysis rate coefficients (j(NO2)) - are compared. The measurements were performed with two calibrated a 2 pi -actinometers assembled on the azimuth angle-controlled LPMA/DOAS (Laboratoire de Physique Moleculaire et Applications / Differential Optical Absorption Spectroscopy) gondola during a series of balloon flights. Since the actinometer's spectral sensitivity curve did not exactly match the actinic spectrum of NO2 and the skylight's spectrum shape changes with atmospheric height and solar illumination, only proxies (proxy-)j(NO2) rather than true j(NO2) values were monitored during balloon ascents (0-30 km) for solar zenith angle (SZA) 75 degrees < SZA < 86 degrees, and at balloon float altitude during solar occultation (86 degrees < SZA < 95 degrees). The measured direct and diffuse total proxy-j(NO2), values compare excellently with radiative transfer (RT) modeling. That finding allows us to rule out uncertainties in computing UV/vis actinic fluxes as a significant factor in the still insufficient modeling of stratospheric NO2 at large SZAs. C1 Univ Heidelberg, Inst Umweltphys, INF 229, D-69120 Heidelberg, Germany. Univ Paris 06, CNRS, LPMA, Paris, France. Univ Leeds, Sch Environm, Leeds, W Yorkshire, England. Max Planck Inst Chem, Mainz, Germany. FZ Julich, Inst Stratosphar Chem, Julich, Germany. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Bosch, H (reprint author), Univ Heidelberg, Inst Umweltphys, INF 229, D-69120 Heidelberg, Germany. RI Schiller, Cornelius/B-1004-2013; Chipperfield, Martyn/H-6359-2013; Harder, Hartwig/L-2511-2014; Boesch, Hartmut/G-6021-2012; Schneider, Matthias/B-1441-2013 OI Chipperfield, Martyn/0000-0002-6803-4149; Harder, Hartwig/0000-0002-6868-714X; NR 22 TC 11 Z9 11 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 APR 1 PY 2001 VL 28 IS 7 BP 1179 EP 1182 DI 10.1029/2000GL012134 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 415GZ UT WOS:000167714000003 ER PT J AU Rosenlof, KH Oltmans, SJ Kley, D Russell, JM Chiou, EW Chu, WP Johnson, DG Kelly, KK Michelsen, HA Nedoluha, GE Remsberg, EE Toon, GC McCormick, MP AF Rosenlof, KH Oltmans, SJ Kley, D Russell, JM Chiou, EW Chu, WP Johnson, DG Kelly, KK Michelsen, HA Nedoluha, GE Remsberg, EE Toon, GC McCormick, MP TI Stratospheric water vapor increases over the past half-century SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPOPAUSE TEMPERATURES; AIRCRAFT MEASUREMENTS; ATMOSPHERIC METHANE; SOUTHERN ENGLAND; HUMIDITY; TRENDS; OZONE; VARIABILITY; WASHINGTON; HYGROMETER AB Ten data sets covering the period 1954-2000 are analyzed to show a 1%/yr increase in stratospheric water vapor. The trend has persisted for at least 45 years, hence is unlikely the result of a single event, but rather indicative of long-term climate change. A long-term change in the transport of water vapor into the stratosphere is the most probable cause. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. NOAA, CMDL, Boulder, CO 80305 USA. Forschungszentrum Julich, Julich, Germany. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Sandia Natl Labs, Livermore, CA 94551 USA. USN, Res Lab, Washington, DC 20375 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Rosenlof, KH (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80305 USA. EM krosenlof@al.noaa.gov RI Rosenlof, Karen/B-5652-2008; Johnson, David/F-2376-2015 OI Rosenlof, Karen/0000-0002-0903-8270; Johnson, David/0000-0003-4399-5653 NR 29 TC 198 Z9 205 U1 2 U2 19 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 APR 1 PY 2001 VL 28 IS 7 BP 1195 EP 1198 DI 10.1029/2000GL012502 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 415GZ UT WOS:000167714000007 ER PT J AU Milly, PCD Dunne, KA AF Milly, PCD Dunne, KA TI Trends in evaporation and surface cooling in the Mississippi River basin SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID UNITED-STATES; NORTHERN WINTER; PRECIPITATION; CLIMATE AB A synthesis of available data for the Mississippi River basin (area 3x10(6) km(2)) reveals an upward trend in evaporation during recent decades, driven primarily by increases in precipitation and secondarily by human water use. A cloud-related decrease in surface net radiation appears to have accompanied the precipitation trend. Resultant evaporative and radiative cooling of the land and lower atmosphere quantitatively explains downward trends in observed pan evaporation. These cooling tendencies also reconcile the observed regional atmospheric cooling with the anticipated regional "greenhouse warming." If recent high levels of precipitation (which correlate with the North Atlantic Oscillation) are mainly caused by an internal climatic fluctuation, an eventual return to normal precipitation could reveal heretofore-unrealized warming in the basin. If, instead, they are caused by some unidentified forcing that will continue to grow in the future, then continued intensification of water cycling and suppression of warming in the basin could result. 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, POB 308, Princeton, NJ 08542 USA. NR 25 TC 73 Z9 77 U1 2 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 2001 VL 28 IS 7 BP 1219 EP 1222 DI 10.1029/2000GL012321 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 415GZ UT WOS:000167714000013 ER PT J AU Lee, X Bullock, OR Andres, RJ AF Lee, X Bullock, OR Andres, RJ TI Anthropogenic emission of mercury to the atmosphere in the northeast United States SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID COMBUSTION SOURCES; CARBON-MONOXIDE; GASEOUS MERCURY; AIR; SPECIATION; WATER; FLUX; DEPOSITION; TRANSPORT; EXCHANGE AB The severity and spatial extent of the health impact of anthropogenic mercury (Hg) emission to the atmosphere depend on the emission rate and chemical form of the emitted species. The few measurements of combustion flue gas give highly variable results about how the emission is divided between the elemental (Hg degrees) and reactive forms and are difficult to extrapolate to a regional scale. Here we combine measurement of total gaseous mercury (TGM) and carbon dioxide (CO2) concentrations at a background site in the winter with carbon (C) emission inventory to show that at a regional (500 km) scale, the effective anthropogenic Hg-degrees flux is 41(+/-2) g km(-2) yr(-1) in the north-east United States. This regional-scale flux was higher under clear skies than under cloudy skies, suggesting some removal of Hg degrees by cloud water, but the physical mechanisms of the removal are yet to be identified. C1 Yale Univ, Sch Forestry & Environm Studies, New Haven, CT 06511 USA. NOAA, Air Resources Lab, Res Triangle Pk, NC USA. Univ Alaska, Fairbanks, AK 99701 USA. RP Lee, X (reprint author), Yale Univ, Sch Forestry & Environm Studies, 370 Prospect St, New Haven, CT 06511 USA. RI ANDRES, ROBERT/B-9786-2012 NR 24 TC 10 Z9 11 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 2001 VL 28 IS 7 BP 1231 EP 1234 DI 10.1029/2000GL012274 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 415GZ UT WOS:000167714000016 ER PT J AU Viereck, R Puga, L McMullin, D Judge, D Weber, M Tobiska, WK AF Viereck, R Puga, L McMullin, D Judge, D Weber, M Tobiska, WK TI The MgII Index: A proxy for solar EUV SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID IRRADIANCE MEASUREMENTS; ULTRAVIOLET IRRADIANCE; FLUX MODEL; VARIABILITY; SPECTRUM; DENSITY AB This paper shows that the Mg II core-to-wing ratio is a better proxy for Solar Extreme Ultraviolet (EUV) radiation, between 25 and 35 nm than is the F10.7 index. The He II 30.4 nm solar emission, by itself, is an important source of energy for the upper atmosphere. We will compare the NOAA Mg II Index and the F10.7 Index to the He If 30.4 data taken with the CELIAS/Solar EUV Monitor (SEM) on the Solar and Helospheric Observatory (SOHO). C1 NOAA, Space Environm Ctr, Boulder, CO 80305 USA. Univ So Calif, Ctr Space Sci, Los Angeles, CA USA. Univ Bremen, Inst Environm Phys, D-2800 Bremen 33, Germany. Fed Data Corp, Pasadena, CA USA. RP Viereck, R (reprint author), NOAA, Space Environm Ctr, 325 Broadway, Boulder, CO 80305 USA. RI Weber, Mark/F-1409-2011 OI Weber, Mark/0000-0001-8217-5450 NR 15 TC 92 Z9 94 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 2001 VL 28 IS 7 BP 1343 EP 1346 DI 10.1029/2000GL012551 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 415GZ UT WOS:000167714000044 ER PT J AU Fanslow, DL Nalepa, TF Johengen, TH AF Fanslow, DL Nalepa, TF Johengen, TH TI Seasonal changes in the respiratory electron transport system (ETS) and respiration of the zebra mussel, Dreissena polymorpha in Saginaw Bay, Lake Huron SO HYDROBIOLOGIA LA English DT Article DE seasonal respiration; oxygen uptake; mussel activity; R : ETS ratio; Great Lakes ID PHYSIOLOGICAL ENERGETICS; OXYGEN-CONSUMPTION; MARINE ZOOPLANKTON; GROWTH EFFICIENCY; NORTH-AMERICA; GREAT-LAKES; PHYTOPLANKTON; RATES; COLONIZATION; POPULATIONS AB Electron transport system activity (ETS) and respiration rates (R) of the zebra mussel, Dreissena polymorpha, were determined monthly from April to November over 2 years at two sites in Saginaw Bay, Lake Huron. The sites were located in the inner and outer bay and contrasted in food quantity and quality. ETS ranged from 2 to 40 mug O-2 mg DW-1 h(-1) over the study period. Both ETS and respiration were strongly related to temperature, and maximum values were found between June and August. ETS also peaked in June/July when assays were conducted at a constant temperature (25 degreesC), indicating other factors besides temperature affected metabolic activity. R:ETS ratios decreased with increased temperature at the inner bay site, but trends were minimal at the outer bay site. In late summer, blooms of the cyanophyte Microcystis occurred in the inner bay, likely depressing filtration rates, and leading to lower respiration rates relative to ETS. ETS activity was consistently higher in the outer bay and was likely a result of higher food quality. Despite these spatial differences, annual mean R:ETS ratios varied only from 0.04 to 0.09 at the two sites over the 2-year period. Based on these values, ETS may be useful as an indicator of long-term metabolic activity in annual energy budgets of D. polymorpha. However, food conditions differentially affect respiration relative to ETS, and variability in this ratio must be considered when interested in shorter time scales. 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 Fanslow, DL (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 43 TC 31 Z9 32 U1 0 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD APR PY 2001 VL 448 IS 1-3 BP 61 EP 70 DI 10.1023/A:1017582119098 PG 10 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 452NA UT WOS:000169863400008 ER PT J AU Fuks, IM AF Fuks, IM TI Wave diffraction by a rough boundary of an arbitrary plane-layered medium SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE bistatic scattering cross section; electromagnetic wave (EM); global position system (GPS); layered media; remote sensing; rough surfaces; scattering ID SCATTERING; SURFACE AB The problem of electromagnetic (EM) wave scattering by a slightly rough boundary of an arbitrary, layered medium is solved by a small perturdation method, The bistatic amplitude of scattering as well as scattering cross sections for statistically rough surface are calculated for linear and circular polarized waves. Along with the scattering into the upgoing waves in the homogeneous medium, the scattering cross sections in the downgoing waves into a layered medium are obtained, Analytical results are applied to the modeling of natural, layered media (ice and sand layers) remote sensing problems employing global position system (GPS) technics. C1 LLC, H Zel Technol, Boulder, CO 80305 USA. NOAA, ERL, ETL, Boulder, CO 80305 USA. RP Fuks, IM (reprint author), LLC, H Zel Technol, Boulder, CO 80305 USA. NR 17 TC 40 Z9 42 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD APR PY 2001 VL 49 IS 4 BP 630 EP 639 DI 10.1109/8.923325 PG 10 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 431PQ UT WOS:000168640100017 ER PT J AU Benz, SP Burroughs, CJ Dresselhaus, PD Christian, LA AF Benz, SP Burroughs, CJ Dresselhaus, PD Christian, LA TI AC and DC voltages from a Josephson arbitrary waveform synthesizer SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE digital-analog conversion; frequency control; frequency domain synthesis; frequency synthesizers; Josephson arrays; signal synthesis; standards; superconducting microwave devices; superconducting-normal-superconductor; devices; voltage control ID STANDARD AB We have synthesized and measured ac and de voltages using a Josephson arbitrary waveform synthesizer, On-chip filtering has enabled the first practical operating margins for ac and arbitrary waveforms, Using a digital voltmeter, we demonstrate the operating margins and linearity of 101 synthesized de voltages and confirm the flatness of a single voltage step. We present the first ac-dc and ac-ac voltage measurements of the synthesizer at 3.65 mV using an ac-dc thermal transfer standard. This quantum-based standard source can be used to measure the ac-dc difference of thermal transfer standards at small voltages. C1 Natl Inst Stand & Technol, Div Electromagnet Technol, Elect & Elect Engn Lab, Boulder, CO 80303 USA. Measurement Stand Lab New Zealand, Lower Hutt, New Zealand. RP Natl Inst Stand & Technol, Div Electromagnet Technol, Elect & Elect Engn Lab, Boulder, CO 80303 USA. NR 10 TC 30 Z9 30 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9456 EI 1557-9662 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 181 EP 184 DI 10.1109/19.918096 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200003 ER PT J AU Jeanneret, B Rufenacht, A Burroughs, CJ AF Jeanneret, B Rufenacht, A Burroughs, CJ TI High precision comparison between SNS and SIS Josephson voltage standards SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE electrical measurements; Josephson arrays; voltage standard; Zener diodes AB Recently, a new Josephson voltage standard based on a 1 V programmable chip provided by the National Institute of Standards and Technology (NIST) was implemented at the Swiss Federal Office of Metrology (OFMET). A comparison with a conventional Josephson voltage standard showed an agreement of (1.4 +/- 3.4) X 10(-10) at 1 V, This result demonstrates the new system is functioning properly and can be used in various types of measurements. In particular it will be one of the key components of the Watt balance experiment [1] that is presently under construction at OFMET. C1 Swiss Fed Off Metrol, CH-3003 Bern, Switzerland. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Jeanneret, B (reprint author), Swiss Fed Off Metrol, CH-3003 Bern, Switzerland. NR 12 TC 20 Z9 20 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 188 EP 191 DI 10.1109/19.918098 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200005 ER PT J AU Reymann, D Witt, TJ Vrabcek, P Tang, YH Hamilton, CA Katkov, AS Jeanneret, B Power, O AF Reymann, D Witt, TJ Vrabcek, P Tang, YH Hamilton, CA Katkov, AS Jeanneret, B Power, O TI Recent developments in BIPM voltage standard comparisons SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB The Bureau International des Poids ct Measures (BIPM) carries out a number of comparisons of de voltage standards with National Metrology Institutes (NMIs). These take the form of on-site comparisons of Josephson standards or bilateral comparisons using traveling standards based on Zener diodes. This paper describes some of the new procedures used in both types of comparison and presents some results of five recent BIPM key comparisons. C1 Bur Int Poids & Mesures, F-92312 Sevres, France. SMU, Slovak Inst Metrol, F-92312 Sevres, France. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Inst Metrol, St Petersburg, Russia. Swiss Fed Off Metrol, CH-3003 Bern, Switzerland. Natl Metrol Lab, Dublin, Ireland. RP Reymann, D (reprint author), Bur Int Poids & Mesures, F-92312 Sevres, France. NR 9 TC 9 Z9 10 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 206 EP 209 DI 10.1109/19.918103 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200010 ER PT J AU Tang, YH Miller, WB AF Tang, YH Miller, WB TI Interlaboratory comparison of Josephson voltage standards between NIST and Lockheed Martin Astronautics SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE intercomparison; Josephson voltage standard (JVS); measurement assurance program (MAP); uncertainty; Zener pressure correction AB Two Josephson voltage standard (JVS) systems operated at the National institute of Standards and Technology (NIST) and Lockheed Martin Astronautics (LMA) were compared by using four traveling Zener standards. A Measurement Assurance Program MAP) protocol was adopted for the comparison, The Zener data were first corrected based on their pressure coefficients to compensate for the pressure difference due to the lab elevations and local meteorological conditions. The Welch-Satterthwaite formula and effective degrees of freedom DOF) were then used to calculate the expanded uncertainty. The mean difference between the measurements of the two laboratories was found to be 0.059 muV with an expanded uncertainty of +/- 0.189 muV at the 95% confidence level. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Lockheed Martin Space Syst Co, Astronaut Operat, Denver, CO 80201 USA. RP Tang, YH (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 4 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 210 EP 213 DI 10.1109/19.918104 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200011 ER PT J AU Schumacher, B Warnecke, P Poirier, W Delgado, I Msimang, Z Boella, G Hetland, PO Elmquist, RE Williams, J Inglis, D Jeckelmann, B Gunnarsson, O Satrapinsky, A AF Schumacher, B Warnecke, P Poirier, W Delgado, I Msimang, Z Boella, G Hetland, PO Elmquist, RE Williams, J Inglis, D Jeckelmann, B Gunnarsson, O Satrapinsky, A TI Transport behavior of commercially available 100-Omega standard resistors SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE cryogenic electronics; Hall effect; resistance measurement; resistors; transfer standard ID EFFECT RESISTANCE STANDARDS; BIPM; TEMPERATURE AB Several types of commercial 100-Omega resistors can be used with the cryogenic current comparator to maintain the resistance unit, derived from the quantized Hall effect (QHE), and to disseminate this unit to laboratory resistance standards, Up until now, the transport behavior of these resistors has not been investigated. Such an investigation is of importance for carrying out comparisons that are close to the level of a direct comparison of two QHE apparatuses, A set of five 100-Omega resistors from three different manufacturers has been sent to 11 participating national metrological institutes. Ah laboratories but one have measured the resistors based on their laboratory's quantized Hall resistance measurements. A constant drift model has been applied, and the results are evaluated in such a way that the transport properties of these resistors are treated independently for the different types of resistor, Under certain conditions, these resistors allow comparisons with uncertainties better than 1 part in 10(8). C1 Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany. Lab Cent Ind Elect, Paris, France. CEM, Madrid, Spain. CSIR, Natl Metrol Lab, ZA-0001 Pretoria, South Africa. Ist Elettrotecn Nazl Galileo Ferraris, Turin, Italy. Justervesenet, Kjeller, Norway. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Natl Phys Lab, Teddington TW11 0LW, Middx, England. Natl Res Council Canada, Ottawa, ON, Canada. Swiss Fed Off Metrol, Bern, Switzerland. Swedish Natl Testing & Res Inst, Boras, Sweden. MIKES, Espoo 02150, Finland. RP Schumacher, B (reprint author), Phys Tech Bundesanstalt, D-38116 Braunschweig, Germany. NR 9 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 242 EP 244 DI 10.1109/19.918112 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200019 ER PT J AU Jarrett, DG AF Jarrett, DG TI Analysis of a dual-balance high-resistance bridge at 10 T Omega SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE balance; bridge; detector; guard; measurement; resistance; standard; transfer standard ID STANDARD RESISTORS AB The NIST guarded active-arm bridge, using a third de source and a second detector to balance the guard network, is described. Improvements to the NIST active-arm bridge and the design and construction of improved high resistance standards have facilitated the extension of MST calibration services to the 10 T Omega decade of resistance. The 10 T Omega calibration service has been offered as a special test for NIST customers; the 100 T Omega special test will be available later this year. To ensure the quality of the measurements provided to the customer and to evaluate the bridge, many verifications including the use of check standards, redundant measurement systems, and multiple bridge ratios have been used, Analysis techniques described here for the 10 T Omega decade of resistance can also be applied to the 100 T Omega decade of resistance. C1 Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab, Technol Adm,US Dept Commerce, Gaithersburg, MD 20899 USA. RP Jarrett, DG (reprint author), Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab, Technol Adm,US Dept Commerce, Gaithersburg, MD 20899 USA. NR 9 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 249 EP 254 DI 10.1109/19.918114 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200021 ER PT J AU Tang, YH Sims, JE AF Tang, YH Sims, JE TI Complete characterization of Zener standards at 10 V for measurement assurance program (MAP) SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE correlation functions; environmental effects; measurement assurance program; uncertainty; Zener standards ID VOLTAGE STANDARDS AB A complete characterization of Zener standards for temperature, pressure, and humidity is being performed to improve the uncertainty of a measurement assurance program (MAP) that uses 10 V Zeners as travelling standards. The procedure and equipment used for this work is briefly described. For the Zener standards we have tested; the temperature coefficients range from (1.6 to 5.4) nV/Omega expressed by Zener output change versus thermistor resistance, and the pressure coefficients range from (1 to 20) nV/hPa, The time constant of Zener response to relative humidity change varies from days to nearly infinity. By choosing low noise and nonhumidity sensitive Zeners as transfer standards and correcting for the pressure and temperature effects, the uncertainties of a MAP can be improved. C1 NIST, Div Elect, Elect & Elect Engn Lab, Technol Adm,US Dept Commerce, Gaithersburg, MD 20899 USA. RP Tang, YH (reprint author), NIST, Div Elect, Elect & Elect Engn Lab, Technol Adm,US Dept Commerce, Gaithersburg, MD 20899 USA. NR 4 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 263 EP 266 DI 10.1109/19.918117 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200024 ER PT J AU Elmquist, RE Jeffery, AM Jarrett, DG AF Elmquist, RE Jeffery, AM Jarrett, DG TI Characterization of four-terminal-pair resistance standards: A comparison of measurements and theory SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE AC measurements; calculable frequency dependence; coaxial resistance standards; four-terminal-pair measurements; straight wire resistance standards AB Coaxial straight-mire resistance standards with calculable frequency dependence link ac measurements to de measurements of resistance. Here, several coaxial standards of values 100 Omega and 1000 Omega are compared with each other and with other resistance standards at frequencies of 1592 Hz (omega congruent to 10(4)) and 15920 Hz (omega congruent to 10(5)) using ac bridges. The data are compared with calculations based on the geometry of this resistor design, Our results provide;good assurance that the calculations are accurate for the quadrature component of admittance (phase angle), which is directly proportional to frequency. Frequency-dependent contributions to the in-phase component of admittance, which increase as the square of the frequency, are larger than predicted by the calculations. C1 NIST, Div Elect, Elect & Elect Engn Lab, Technol Adm,US Dept Commerce, Gaithersburg, MD 20899 USA. RP Elmquist, RE (reprint author), NIST, Div Elect, Elect & Elect Engn Lab, Technol Adm,US Dept Commerce, Gaithersburg, MD 20899 USA. NR 10 TC 5 Z9 6 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 267 EP 271 DI 10.1109/19.918118 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200025 ER PT J AU Lipe, TE Kinard, JR Reintsema, CD AF Lipe, TE Kinard, JR Reintsema, CD TI Improvements in the NIST cryogenic thermal transfer standard SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE AC-DC difference; cryogenic converter; primary standards; thermal converters ID AC-DC TRANSFER; CONVERTERS AB We describe the development of a cryogenic thermal transfer standard (CTTS) from the first prototype in 1997 to the present version. A description of the superconducting transition-edge sensor and the development of a superconducting input transmission line are given. We also present data demonstrating the performance of the CTTS. C1 Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Electromagnet Technol Div, Elect & Elect Engn Lab, Boulder, CO 80303 USA. RP Lipe, TE (reprint author), Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. NR 8 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 326 EP 329 DI 10.1109/19.918133 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200040 ER PT J AU Wunsch, TF Kinard, JR Manginell, RP Solomon, OM Lipe, TE Jungling, KC AF Wunsch, TF Kinard, JR Manginell, RP Solomon, OM Lipe, TE Jungling, KC TI A new fabrication process for planar thin-film multijunction thermal converters SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE AC-DC transfer; metrology; standard; thermal converter; voltage AB Advanced thin-film processing and packaging technologies are employed in the fabrication of new planar thin-film multijunction thermal converters (MJTCs). The processing, packaging, and design features build on experience gained from prior NIST demonstrations of thin-film converters and are optimized for improved sensitivity, bandwidth, manufacturability, and reliability. C1 Natl Inst Stand & Technol, Elect Engn Lab, Div Elect, Gaithersburg, MD 20899 USA. Univ New Mexico, Albuquerque, NM 87106 USA. RP Wunsch, TF (reprint author), Natl Inst Stand & Technol, Elect Engn Lab, Div Elect, Gaithersburg, MD 20899 USA. NR 4 TC 16 Z9 16 U1 0 U2 6 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 APR PY 2001 VL 50 IS 2 BP 330 EP 332 DI 10.1109/19.918134 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200041 ER PT J AU Filipski, PS van Mullem, CJ Janik, D Klonz, M Kinard, JR Lipe, TE Waltrip, BC AF Filipski, PS van Mullem, CJ Janik, D Klonz, M Kinard, JR Lipe, TE Waltrip, BC TI Comparison of high-frequency AC-DC voltage transfer standards at NRC, VSL, PTB, and NIST SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE AC-DC transfer; calibration; coaxial transmission lines; electric variables measurement; measurement standard; thermal converter ID DIFFERENCE; MHZ AB The paper summarizes results of two international comparisons relating thermal voltage converter (TVC) HF voltage standards of the National Research Council of Canada (NRC) to the standards of three National Metrology Institutes (NMIs): NMi Van Swinden Laboratorium (VSL), The Netherlands, Physikalisch-Technische Bundesanstalt (PTB), Germany, and National Institute of Standards and Technology (NIST), USA. The first comparison was part of the CCE 92-05 Intercomparison of AC-DC Voltage Transfer Standards at HF (1-50 MHz), [1], The second comparison was carried out using a calorimetric thermal voltage converter (CTVC) of MRC design, Results of both comparisons show very good agreement in the frequency range (10 Hz-100 MHz) between NRC and the three other NMIs, thus validating the design of the NRC CTVC as a wideband reference standard of the ac-dc voltage transfer difference [2]. C1 Natl Res Council Canada, INMS, Ottawa, ON K1A 0R6, Canada. NMi Van Swinden Lab, NL-2600 AR Delft, Netherlands. Phys Tech Bundesanstalt, D-3816 Braunschweig, Germany. Natl Inst Stand & Technol, Div Elect, Gaithersburg, MD 20899 USA. RP Filipski, PS (reprint author), Natl Res Council Canada, INMS, Ottawa, ON K1A 0R6, Canada. NR 9 TC 4 Z9 4 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 349 EP 352 DI 10.1109/19.918139 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200046 ER PT J AU So, E Angelo, D Nelson, T Snider, L AF So, E Angelo, D Nelson, T Snider, L TI NRC-NIST comparison of power meter calibrations at 60 Hz and ranges up to 600 V, 100 A SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE international comparison; power meter calibrations ID CURRENT-COMPARATOR; VOLTAGE AB A number of international comparisons of power meter calibrations at power frequencies were conducted in the past, all of them being done at 120 V and 5 A. This comparison of power meter calibrations between the National Research Council of Canada and the National Institute of Standards and Technology, USA, was done to include voltage ranges up to 600 V, current ranges up to 100 A, and at power factors of 1.0, 0.5 lead and lag, and 0.0 lead and lag. The comparison was implemented by a transfer standard consisting of a modified commercial time-division multiplier type wattmeter based on a development at the National Research Council of Canada. The results indicate that there are no significant differences in the overall accuracy of ac power measurements in each laboratory up to 600 V, 100 A, at all power factors. C1 Natl Res Council Canada, Ottawa, ON K1A 0R6, Canada. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP So, E (reprint author), Natl Res Council Canada, Ottawa, ON K1A 0R6, Canada. NR 7 TC 1 Z9 1 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 353 EP 355 DI 10.1109/19.918140 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200047 ER PT J AU Oldham, N Nelson, T Bergeest, R Ramm, G Carranza, R Corney, AC Gibbes, M Kyriazis, G Laiz, HM Liu, LX Lu, Z Pogliano, U Rydler, KE Shapiro, E So, E Temba, M Wright, P AF Oldham, N Nelson, T Bergeest, R Ramm, G Carranza, R Corney, AC Gibbes, M Kyriazis, G Laiz, HM Liu, LX Lu, Z Pogliano, U Rydler, KE Shapiro, E So, E Temba, M Wright, P TI An international comparison of 50/60 Hz power (1996-1999) SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID TRANSFER STANDARD; FREQUENCIES; COMPARATOR; SYSTEM; ENERGY AB An international comparison of 50/60 Hz power is described. The traveling standard was an electronic power transducer that was tested at 120 V, 5 A, 53 Hz, at five power factors (1.0, 0.5, and 0.0). Fifteen National Metrology Institutes (NMIs) from six metrology regions participated in the comparison. C1 NIST, Div Elect, Elect & Elect Engn Lab, Technol Adm, Gaithersburg, MD 20899 USA. Phys Tech Bundesanstalt, D-3816 Braunschweig, Germany. CENAM, Queretaro 76900, Mexico. Ind Res Ltd, Measurement Stand Lab New Zealand, Lower Hutt, New Zealand. CSIRO, Natl Measurement Lab, Lindfield, NSW 2070, Australia. Natl Inst Metrol, INMETRO, BR-25250020 Rio De Janeiro, Brazil. INTI, RA-1650 San Martin, Argentina. Singapore Product & Stand Board, Natl Measurement Ctr, Singapore, Singapore. NIM, Beijing 100013, Peoples R China. Ist Elettrotecnico Nazl Galileo Ferraris, I-10135 Turin, Italy. SP Swedish Natl Testing & Res Inst, SE-50115 Boras, Sweden. DI Mendeleyev Inst Metrol, St Petersburg 198005, Russia. Natl Res Council Canada, Inst Natl Measurement Stand, Ottawa, ON K1A 0R6, Canada. CSIR, Natl Metrol Lab, ZA-0001 Pretoria, South Africa. Natl Phys Lab, Teddington TW11 0LW, Middx, England. RP NIST, Div Elect, Elect & Elect Engn Lab, Technol Adm, Gaithersburg, MD 20899 USA. NR 17 TC 13 Z9 13 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9456 EI 1557-9662 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 356 EP 360 DI 10.1109/19.918141 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200048 ER PT J AU Randa, J Dunleavy, LP Terrell, LA AF Randa, J Dunleavy, LP Terrell, LA TI Stability measurements on noise sources SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE noise; noise measurement; noise source; noise temperature; stability; thermal noise AB We report results of stability and repeatability measurements performed on a selection of different noise sources for selected frequencies between 12 GHz and 26.5 GHz. Measurements cover intervals classified as intermediate term (about 1 week) and long term (about 1 year of more). Noise sources measured include a commercial diode source, a gas-discharge source constructed by NIST, a specially modified commercial diode source, and a variable-temperature FET-based source. All sources exhibit excellent stability, typically consistent with zero drift in noise temperature within the uncertainty of the tests. C1 Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder, CO 80305 USA. Univ S Florida, Dept Elect Engn, Tampa, FL 33620 USA. RP Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder, CO 80305 USA. NR 6 TC 9 Z9 10 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9456 EI 1557-9662 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 368 EP 372 DI 10.1109/19.918144 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200051 ER PT J AU Achkar, J Mellouet, B Velasco, L Swarnowski, S Akhiezer, AN Seredniy, VP Pavlenko, YF Juroshek, JR AF Achkar, J Mellouet, B Velasco, L Swarnowski, S Akhiezer, AN Seredniy, VP Pavlenko, YF Juroshek, JR TI The GT-RF/95-1 key comparison of power measurements at 62 GHz SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE effective efficiency; international comparison; power; power measurement; reflection coefficient AB An international key comparison of effective efficiency was carried out from 1996 to 1998 between four National Metrology Institutes (NMIs) at 62 GHz in IEC R620 rectangular waveguide standard, The traveling item was a waveguide temperature compensated thermistor mount. The following NMIs participated: National Physical Laboratory (NPL), Malvern, U,K,; State Scientific Industrial Association (SSIA), Kharkov, Ukraine; National Institute of Standards and Teehnology (NIST), Boulder, CO; and Bureau National de Metrologie-Laboratoire Central des Industries Electriques (BNM-LCIE), Fontenay-aux-Roses, France, which acted as the pilot laboratory for the GT-RF/95-1 key comparison. Good agreement was found among the results from the different NMIs, with all results agreeing within one standard uncertainty (kappa = 1), which ranged from approximately 0.5% to 0.9%. C1 LCIE, BNM, F-92266 Fontenay Aux Roses, France. NPL, Malvern, Worcs, England. SISA Metrol, Kharkov, Ukraine. Natl Inst Stand & Technol, Boulder, CO 80301 USA. RP Achkar, J (reprint author), LCIE, BNM, F-92266 Fontenay Aux Roses, France. NR 8 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 406 EP 408 DI 10.1109/19.918153 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200060 ER PT J AU Larason, TC Brown, SW Eppeldauer, GP Lykke, KR AF Larason, TC Brown, SW Eppeldauer, GP Lykke, KR TI Responsivity calibration methods for 365-nm irradiance meters SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE calibration; irradiance; photodetectors; radiometry; spectral responsivity; ultraviolet ID FILTER RADIOMETERS AB Two detector-based responsivity calibration methods have been compared at the National Institute of Standards and Technology for ultraviolet irradiance meters in the 365-nm spectral region. Both methods are based on an electrical substitution high-accuracy cryogenic radiometer, but utilize different facilities and transfer standards. One facility is a monochromator-based spectral-power responsivity measuring system utilizing an aperture-scanning method, while the second is a tunable-laser and integrating-sphere source system using a light-trapping silicon transfer detector with a known aperture area. The first reported comparison of these two fundamentally different methods agreed to 1%-2% near the peak and long wavelength side of the bandpass curves which is comparable to their expanded (k = 2) uncertainties. C1 Natl Inst Stand & Technol, Opt Technol Div, Phys Lab, US Dept Commerce, Gaithersburg, MD 20899 USA. RP Larason, TC (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Phys Lab, US Dept Commerce, Gaithersburg, MD 20899 USA. NR 7 TC 4 Z9 4 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 474 EP 477 DI 10.1109/19.918169 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200076 ER PT J AU Migdall, AL AF Migdall, AL TI Absolute quantum efficiency measurements using correlated photons: Toward a measurement protocol SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE photodetectors; quantum efficiency; radiometry AB Correlated photons can be used to measure the quantum efficiency of photon counting photodetectors without ties to any externally calibrated standards. We present a study of measurement systematics aimed at reducing the measurement uncertainties to the 0.1% level, and developing a robust measurement protocol. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 7 TC 13 Z9 14 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9456 EI 1557-9662 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 478 EP 481 DI 10.1109/19.918170 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200077 ER PT J AU Heavner, TP Hollberg, L Jefferts, SR Kitching, J Klipstein, WM Meekhof, DM Robinson, HG AF Heavner, TP Hollberg, L Jefferts, SR Kitching, J Klipstein, WM Meekhof, DM Robinson, HG TI Characterization of a cold cesium source for PARCS: Primary atomic reference clock in space SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB The Primary Atomic Reference Clock in Space (PARCS) project is a joint NIST-JPL-University of Colorado venture aimed at placing a Cs atomic clock aboard the International Space Station (ISS). This orbiting clock will achieve high accuracy, in part due to the long Ramsey times afforded by the microgravity environment, and allow for precision tests of fundamental physics including relativity theory. As pare of this effort, we are evaluating the characteristics of a prototype cold Cs source based on launching atoms from an optical molasses, Experimental results, in conjunction with theoretical modeling of atom flux requirements, will be applied to the design and construction of a robust, space-qualified device. The apparatus described here will be used to develop other PARCS components such as the microwave cavity structure and detection systems, and to investigate two-dimensional cooling schemes for future Cs fountains and space clocks. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. NR 6 TC 7 Z9 9 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9456 EI 1557-9662 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 500 EP 502 DI 10.1109/19.918176 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200083 ER PT J AU Meekhof, DM Jefferts, SR Stepanovic, M Parker, TE AF Meekhof, DM Jefferts, SR Stepanovic, M Parker, TE TI Accuracy evaluation of a cesium fountain primary frequency standard at NIST SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID SHIFT AB A new laser-cooled Cs fountain primary frequency standard has been constructed at the National Institute of Standards and Technology (NIST) in Boulder, CO. The new standard, NIST-F1, is described here, including details of systematic frequency biases for which frequency corrections are made. We have submitted two evaluations to the Bureau International des Poids et Mesures (BIPM), which have Type A (statistical) uncertainties less than 1.5 x 10(-15) and Type B (systematic) uncertainties less than 0.9 x 10(-15). C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Meekhof, DM (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 14 TC 15 Z9 15 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 507 EP 509 DI 10.1109/19.918178 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200085 ER PT J AU Diddams, SA Jones, DJ Ye, J Cundiff, ST Hall, JL Ranka, JK Windeler, RS AF Diddams, SA Jones, DJ Ye, J Cundiff, ST Hall, JL Ranka, JK Windeler, RS TI Direct RF to optical frequency measurements with a femtosecond laser comb SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE frequency measurement; laser stability; optical frequency conversion; optical spectroscopy ID 2-PHOTON TRANSITION; PHASE-CONTROL; GENERATION; RUBIDIUM; NM AB By spanning an optical octave (> 300 THz) with a broadened femtosecond laser frequency comb, we directly measure the frequencies of optical standards at 1064/532 nm, 633 nm and 778 nm in terms of the microwave frequency that controls the tomb spacing. This microwave frequency can be linked directly to the cesium standard. C1 Univ Colorado, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Univ Colorado, Boulder, CO 80309 USA. RI Cundiff, Steven/B-4974-2009; Ye, Jun/C-3312-2011; Diddams, Scott/L-2819-2013; Jones, David/F-5859-2017 OI Cundiff, Steven/0000-0002-7119-5197; NR 14 TC 10 Z9 11 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9456 EI 1557-9662 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 552 EP 555 DI 10.1109/19.918189 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200096 ER PT J AU Taylor, BN Mohr, PJ AF Taylor, BN Mohr, PJ TI The role of fundamental constants in the International System of Units (SI): Present and future SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE ampere; fundamental constants; International System of Units; Josephson effect; kilogram redefinition; ohm; Planck constant; quantum Hall effect; realization of electric units; representations of electric units; SI; volt; watt; watt balance ID CODATA RECOMMENDED VALUES; PHYSICAL CONSTANTS; KILOGRAM AB This paper addresses the role of fundamental constants in 1) the current definitions of the SI base units; 2) practical representations of SI electric units and the consistency of those representations with the SI as deduced from the 1998 CODATA recommended values of the constants; and 3) redefinition of the kilogram and the impact on realizations of SI electric units of a newly proposed definition that fixes the value of the Planck constant h. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Taylor, BN (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 TC 15 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 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 563 EP 567 DI 10.1109/19.918192 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200099 ER PT J AU De Bievre, P Valkiers, S Kessel, R Taylor, PDP Becker, P Bettin, H Peuto, A Pettorruso, S Fujii, K Waseda, A Tanaka, M Deslattes, RD Peiser, HS Kenny, MJ AF De Bievre, P Valkiers, S Kessel, R Taylor, PDP Becker, P Bettin, H Peuto, A Pettorruso, S Fujii, K Waseda, A Tanaka, M Deslattes, RD Peiser, HS Kenny, MJ TI A reassessment of the molar volume of silicon and of the Avogadro constant SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE Avogadro constant; density; molar mass; molar volume; silicon (single crystal) ID DENSITY STANDARDS; SINGLE-CRYSTALS; MASS AB An "absolute" value for the molar volume of Si in Si single crystals is presented as 12.058 820 7(54) cm(3) mol(-1) with a relative standard uncertainty of 4.5 .10(-7). It is argued that the consistency of most of the molar volume determinations is useful for evaluating the quality of the Si single crystals involved. A value for the Avogadro constant is derived as 6.022 133 9(27) 10(23) mol(-1) having a relative standard uncertainty of 4.6 10(-1). C1 Commiss European Communities, Inst Reference Mat & Measurements, Geel, Belgium. Phys Tech Bundesanstalt, Braunschweig, Germany. Ist Metrol Gustavo Colonnetti, Turin, Italy. Natl Res Lab Metrol, Tsukuba, Ibaraki, Japan. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Commonwealth Sci & Ind Res Org, Natl Measurement Lab, Lindfield, NSW, Australia. RP De Bievre, P (reprint author), Commiss European Communities, Inst Reference Mat & Measurements, Geel, Belgium. NR 28 TC 28 Z9 28 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 593 EP 597 DI 10.1109/19.918199 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200106 ER PT J AU Parks, HV Faller, JE Robertson, DS AF Parks, HV Faller, JE Robertson, DS TI A suspended laser interferometer for determining the newtonian constant of gravitation SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE Fabry-Perot interferometer; gravity measurement; Newtonian constant AB Progress is reported on an experiment to measure the Newtonian constant of gravitation G with a suspended Fabry-Perot laser interferometer. With this technique, we measure the deflection of simple pendulums due to the gravitational attraction of tungsten masses. A result for G is expected with a relative uncertainty of 3 x 10(-5). C1 Univ Colorado, Joint Inst Lab Astrophys, Natl Inst Stand & Technol, Boulder, CO 80309 USA. NOAA, NOS, Natl Geodet Survey, CIRES, Boulder, CO 80309 USA. RP Parks, HV (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80309 USA. NR 5 TC 4 Z9 4 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 2001 VL 50 IS 2 BP 598 EP 600 DI 10.1109/19.918200 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 424LF UT WOS:000168233200107 ER PT J AU Williams, DF Alpert, BK AF Williams, DF Alpert, BK TI Causality and waveguide circuit theory SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE causality; characteristic impedance; microwave-circuit theory; minimum phase ID GUIDE AB We develop a new causal power-normalized waveguide equivalent-circuit theory that, unlike its predecessors, results in network parameters usable in both the frequency and time domains in a broad class of waveguides, Enforcing simultaneity of the voltages, currents, and fields and a power normalization fixes all of the parameters of the new theory within a single normalization factor, including both the magnitude and phase of the characteristic impedance of the waveguide. Enforcing simultaneity also ensures that the theory's voltages and currents do not start before their excitation, and that the network parameters of passive devices are causal, a necessary condition for stable time-domain simulations. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Williams, DF (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 15 TC 8 Z9 8 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD APR PY 2001 VL 49 IS 4 BP 615 EP 623 DI 10.1109/22.915434 PN 1 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA 419PF UT WOS:000167957000005 ER PT J AU Rozsa, K Bano, G Gallagher, A AF Rozsa, K Bano, G Gallagher, A TI The location of very small particles in silane RF discharge SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE amorphous materials; gas discharges; photo-voltaic cell materials; plasma applications ID PLASMAS; GROWTH AB The size and location of silicon particles that grow in a pure silane, capacitively coupled RF discharge, are measured by laser light scattering. The discharge conditions were similar to those typically used to produce amorphous silicon devices, except the temperatures is 300 K, At early discharge time, when the particles are small (D similar to 15 nm), they are located at the middle of the discharge. The larger ones that occur at later discharge times form a double layer nearer the electrodes. Surprisingly, the particles are not concentrated at the region of brightest discharge-light, which represents the distribution of high-energy electrons. Yet as expected, the distribution of film deposition on the electrodes fits radical diffusion with a source proportional to light intensity. It is also shown, by tilting the substrate, that a small gradient in plasma potential can have a major effect on particle positions. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. RP Rozsa, K (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Bano, Gregor/S-4884-2016 NR 7 TC 1 Z9 1 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 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 2001 VL 29 IS 2 BP 256 EP 260 DI 10.1109/27.923703 PN 1 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 431ZN UT WOS:000168661800022 ER PT J AU Kondoh, E Baklanov, MR Lin, E Gidley, D Nakashima, A AF Kondoh, E Baklanov, MR Lin, E Gidley, D Nakashima, A TI Comparative study of pore size of low-dielectric-constant porous spin-on-glass films using different methods of nondestructive instrumentation SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS LA English DT Article DE low-dielectric-constant films; pore size distribution; ellipsometry; neutron scattering; positronium annihilation ID THIN-FILMS AB The pore sizes of hydrogen-methyl-siloxane-based porous spin-on-glass (SOG) thin films having different k values (k = 1.8-2.5) are comparatively studied using different nondestructive instrumental ways and also with reference to sorption porosimetry. The pore size and its spread are found to increase with increasing porosity, or with decreasing dielectric constant. C1 Yamanashi Univ, Fac Engn, Dept Mech Syst Engn, Kofu, Yamanashi 4008511, Japan. IMEC, Silicon Proc Technol Div, B-3001 Louvain, Belgium. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Catalysts & Chem Ind Co Ltd, Fine Chem Res Ctr, Fukuoka 8080027, Japan. RP Kondoh, E (reprint author), Yamanashi Univ, Fac Engn, Dept Mech Syst Engn, 4-3-11 Takeda, Kofu, Yamanashi 4008511, Japan. NR 9 TC 38 Z9 39 U1 2 U2 5 PU INST PURE APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG, 4-24-8 SHINBASHI, MINATO-KU TOKYO, 105-004, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 2 JI Jpn. J. Appl. Phys. Part 2 - Lett. PD APR 1 PY 2001 VL 40 IS 4A BP L323 EP L326 DI 10.1143/JJAP.40.L323 PG 4 WC Physics, Applied SC Physics GA 468UU UT WOS:000170777200007 ER PT J AU Buckley, CE Birnbaum, HK Lin, JS Spooner, S Bellmann, D Staron, P Udovic, TJ Hollar, E AF Buckley, CE Birnbaum, HK Lin, JS Spooner, S Bellmann, D Staron, P Udovic, TJ Hollar, E TI Characterization of H defects in the aluminium-hydrogen system using small-angle scattering techniques SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID NEUTRON-SCATTERING; X-RAY; DIFFUSIVITY; SOLUBILITY; BUBBLES; IMPLANTATION; PRESSURE; METALS AB Aluminium foils (99.99% purity) and single crystals (99.999% purity) were charged with hydrogen using a gas plasma method and electrochemical methods, resulting in the introduction of a large amount of hydrogen. X-ray diffraction measurements indicated that within experimental error there was a zero change in lattice parameter after plasma charging. This result is contradictory to almost all other face-centred cubic (f.c.c.) materials, which exhibit a lattice expansion when the hydrogen enters the lattice interstitially. It is hypothesized that the hydrogen does not enter the lattice as an interstitial solute, but instead forms an H-vacancy complex at the surface that diffuses into the volume and then clusters to form H-2 bubbles. Small- and ultra-small-angle neutron scattering (SANS, USANS) and small-angle X-ray scattering (SAXS) were primarily employed to study the nature and agglomeration of the H-vacancy complexes in the Al-H system. The SAXS results were ambiguous owing to double Bragg scattering, but the SANS and USANS investigation, coupled with results from inelastic neutron scattering, and transmission and scanning electron microscopy, revealed the existence of a large size distribution of hydrogen bubbles on the surface and in the bulk of the Al-H system. The relative change in lattice parameter is calculated from the pressure in a bubble of average volume and is compared with the experimentally determined value. C1 Curtin Univ Technol, Dept Appl Phys, Perth, WA 6845, Australia. Univ Illinois, Mat Res Lab, Urbana, IL 61801 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN USA. GKSS Res Ctr Geesthacht GmbH, Inst Mat Res, D-21502 Geesthacht, Germany. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Buckley, CE (reprint author), Curtin Univ Technol, Dept Appl Phys, GPO Box U 1987, Perth, WA 6845, Australia. RI Buckley, Craig/B-6753-2013 OI Buckley, Craig/0000-0002-3075-1863 NR 40 TC 31 Z9 31 U1 1 U2 9 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD APR 1 PY 2001 VL 34 BP 119 EP 129 DI 10.1107/S0021889800018239 PN 2 PG 11 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 416PX UT WOS:000167790300005 ER PT J AU Popa, NC Balzar, D AF Popa, NC Balzar, D TI Elastic strain and stress determination by Rietveld refinement: generalized treatment for textured polycrystals for all Laue classes SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID DIFFRACTION AB A novel approach to model diffraction line shifts caused by elastic residual or applied stresses in textured polycrystals is proposed. The model yields the complete strain and stress tensors as a function of crystallite orientation, as well as the average values of the macroscopic strain and stress tensors. It is particularly suitable for implementation in Rietveld refinement programs. The requirements on refinable parameters for all crystal Laue classes are given. The effects of sample symmetry are also included and the conditions for strain invariance to both the sample symmetries (texture and stress/strain) are discussed. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80305 USA. Natl Inst Mat Phys, Bucharest, Romania. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Balzar, D (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80305 USA. RI Popa, Nicolae/B-8182-2011 NR 16 TC 39 Z9 39 U1 1 U2 14 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD APR 1 PY 2001 VL 34 BP 187 EP 195 DI 10.1107/S0021889801002060 PN 2 PG 9 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 416PX UT WOS:000167790300014 ER PT J AU Toby, BH AF Toby, BH TI EXPGUI, a graphical user interface for GSAS SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Software Review AB A description and justification of the EXPGUI program is presented. This program implements a graphical user interface and shell for the GSAS single-crystal and Rietveld package. Use of the Tcl/Tk scripting language allows EXPGUI to be platform independent. Also included is a synopsis of how the program is implemented. C1 Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Toby, BH (reprint author), Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 8 TC 3964 Z9 3995 U1 18 U2 216 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD APR 1 PY 2001 VL 34 BP 210 EP 213 DI 10.1107/S0021889801002242 PN 2 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 416PX UT WOS:000167790300018 ER PT J AU Roy, K Martien, KK AF Roy, K Martien, KK TI Latitudinal distribution of body size in north-eastern Pacific marine bivalves SO JOURNAL OF BIOGEOGRAPHY LA English DT Article DE body size; latitude; bivalves; diversity; biogeography ID SPECIES RICHNESS; BERGMANNS RULE; BATHYMETRIC PATTERNS; EXTINCTION; BIODIVERSITY; DIVERSITY; GRADIENTS; MACROECOLOGY; ASSEMBLAGES; ECTOTHERMS AB Aim To understand the latitudinal patterns in body size distributions of north-eastern Pacific bivalves, as well as the factors influencing those patterns. Locations The north-eastern Pacific continental shelf from 5 degreesS latitude to 70 degreesN latitude. Methods We used data on the body size and latitudinal ranges of 915 species of northeastern Pacific marine bivalves to test for the presence of interspecific latitudinal size trends. We tested for trends in both mean body size as well as variance in body size using randomization tests. Results Overall, there is no significant linear relationship between either mean size or variance in size and latitude. Rather, there is a mid-latitude trough and peak in mean body size and variance in body size, respectively, with changes in the sign of the correlations occurring at provincial boundaries. A significant decreasing trend in mean size with latitude exists within the tropical Panamic province. In contrast, variance in body size shows a significant increasing trend with latitude within the tropics, and a significant decreasing trend with latitude in the cold temperate and Arctic provinces. For north-eastern Pacific bivalves, latitudinal trends in mean body size and variance in body size show very little correlation with latitudinal trends in species richness. Close to an order of magnitude difference in species numbers between tropical and polar latitudes does not appear to significantly affect either mean size or variance in size. Changes in mean body size associated with biogeographic boundaries are significantly larger than changes elsewhere along the range. Main conclusions The spatial distribution of major environmental barriers along the north-eastern Pacific margin plays a major role in structuring the latitudinal distribution of body size in marine bivalves along this coast. C1 Univ Calif San Diego, Div Biol, Sect Ecol Behav & Evolut, La Jolla, CA 92093 USA. SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Univ Calif San Diego, Div Biol, Sect Ecol Behav & Evolut, La Jolla, CA 92093 USA. EM kroy@ucsd.edu NR 57 TC 35 Z9 36 U1 0 U2 8 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0305-0270 EI 1365-2699 J9 J BIOGEOGR JI J. Biogeogr. PD APR PY 2001 VL 28 IS 4 BP 485 EP 493 DI 10.1046/j.1365-2699.2001.00561.x PG 9 WC Ecology; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 455AX UT WOS:000170006300006 ER PT J AU Ross, EA Branham, ML Tebbett, IR AF Ross, EA Branham, ML Tebbett, IR TI High mass clearance of autoantibodies from a murine model of lupus nephritis by immunoadsorption using star-configured polyethylene glycols SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE immunoadsorption; polyethylene glycol; systemic lupus erythematosus; lupus nephritis; histones ID ANTI-DNA ANTIBODY; EXTRACORPOREAL IMMUNOADSORPTION; ERYTHEMATOSUS; POLYMERS; COMPLEX; ADSORPTION; MEMBRANES; REMOVAL; BIND AB The extracorporeal immunoadsorption of antibodies as part of the therapy for human autoimmune diseases has been limited by technology with inadequate and nonselective mass clearance or problems with bioincompatibility. To overcome these shortcomings, we designed a method utilizing star-configured polyethylene glycols (star-PEGs) having up to 63 free arms with immunoreactive (tresylate ester) end-groups for each arm immobilized to a polymer support substrate. The flexibility and length of the arms are thought to allow optimization of epitope presentation and to permit interaction with immunoligands on adjacent arms. To demonstrate efficacy we used an in vitro murine antibody model of human lupus nephritis, wherein we could study the kinetics and mass clearance of hybridoma derived antihistone antibodies from human plasma. Histones were covalently bound to the star-PEG end-groups and the kinetics of antibody adsorption were assessed using a surface plasmon resonance technique. The equilibrium constants of antihistone antibody binding to histone-star-PEGs that were linked to a support grid demonstrated high affinity with a K-A of 3.56E + 07 and a K-D of 2.81E - 08. The optimum reaction conditions were determined to accomplish the hydrophilization of polysulfone (PS; by an aqueous nitration method) and polymethylmethacrylate substrates (PMMA; by hydrazine), using sheet casts of both polymer substances. Hollow fiber devices of these polymers (commercial hemodialyzers) were modified so that histone-bound star-PEGs were linked to their intracapillary luminal surfaces, using a process which we have shown retains their immunoadsorption properties for antihistone antibodies. A dosed loop recirculating model was constructed to measure mass clearance of antibodies from a reservoir. After optimizing conditions using extraction from saline solutions, the removal of antibody from human plasma by control and surface-modified devices was assessed over 4 h. There was no measurable antibody clearance by the control fibers over this time interval. The 2.1 m(2) luminal surface area PMMA devices removed 5.0 +/- 3.3 mg, with a maximum of 7.0 mg. The 1.8 m(2) PS device cleared 11.3 +/- 6.2 mg with a maximum of 17.5 mg. In summary, star-PEG immunoadsorption is a promising technique for the treatment of human autoimmune disease because it can achieve very high-mass clearance of autoantibodies using modified biocompatable hollow-fiber polymer devices. (C) 2001 John Wiley & Sons, Inc. C1 Univ Florida, Coll Med, Div Nephrol Hypertens & Transplantat, Gainesville, FL 32610 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. Univ Florida, Coll Vet Med, Dept Physiol Sci, Gainesville, FL 32610 USA. RP Ross, EA (reprint author), Univ Florida, Coll Med, Div Nephrol Hypertens & Transplantat, Gainesville, FL 32610 USA. NR 25 TC 6 Z9 7 U1 0 U2 7 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 APR PY 2001 VL 55 IS 1 BP 114 EP 120 DI 10.1002/1097-4636(200104)55:1<114::AID-JBM150>3.0.CO;2-Z PG 7 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 398JM UT WOS:000166753400015 PM 11426388 ER PT J AU Coriell, SR McFadden, GB Mitchell, WF Murray, BT Andrews, JB Arikawa, Y AF Coriell, SR McFadden, GB Mitchell, WF Murray, BT Andrews, JB Arikawa, Y TI Effect of flow due to density change on eutectic growth SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE convection; diffusion; directional solidification; eutectics; mass transfer; solidification ID MONOTECTIC COMPOSITE GROWTH; LARGE THERMAL-GRADIENT; LAMELLAR EUTECTICS; HUNT THEORY; JACKSON; SOLIDIFICATION; CONVECTION; MODEL AB The Jackson-Hunt model of eutectic growth is extended to allow for different densities of the phases. The density differences give rise to fluid how which is calculated from a series solution of the fluid flow equations in the Stokes flow approximation. The solute diffusion equation with flow terms is then solved numerically using an adaptive refinement and multigrid algorithm. The interface undercoolings and volume fractions are calculated as a function of spacing for tin-lead and iron-carbon eutectic alloys and for an aluminum-indium monotectic alloy. The numerical results are compared with various approximations based on the Jackson-Hunt analysis. Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. SUNY Binghamton, Dept Mech Engn, Binghamton, NY 13902 USA. Univ Alabama, Dept Mat Sci & Engn, Birmingham, AL 35294 USA. RP McFadden, GB (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8910, Gaithersburg, MD 20899 USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 22 TC 16 Z9 17 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD APR PY 2001 VL 224 IS 1-2 BP 145 EP 154 DI 10.1016/S0022-0248(01)00724-2 PG 10 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 423BX UT WOS:000168156500021 ER PT J AU Lawn, BR AF Lawn, BR TI An engineering perspective of dental layer structures. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT AMER ASSOC DENTAL RESEARCHI A D R/A A D R PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314-3406 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD APR PY 2001 VL 80 IS 4 BP 980 EP 980 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 497VL UT WOS:000172476100296 ER PT J AU Zhao, H Hu, XZ Bush, MB Ford, C AF Zhao, H Hu, XZ Bush, MB Ford, C TI Contact damage analysis of layered dental composites. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Univ Western Australia, Dept Mech & Mat Engn, Nedlands, WA 6907, Australia. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Hu, Xiaozhi /H-4353-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT AMER ASSOC DENTAL RESEARCHI A D R/A A D R PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314-3406 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD APR PY 2001 VL 80 IS 4 BP 980 EP 980 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 497VL UT WOS:000172476100295 ER PT J AU Hirayama, S Takagi, S Chow, LC Ikemi, T AF Hirayama, S Takagi, S Chow, LC Ikemi, T TI Properties of calcium phosphate cements with different phosphate solutions. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Nihon Univ, Sch Dent, Matsudo, Chiba 271, Japan. ADAHF, PRC, NIST, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU INT AMER ASSOC DENTAL RESEARCHI A D R/A A D R PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314-3406 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD APR PY 2001 VL 80 IS 4 BP 1340 EP 1340 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 497VL UT WOS:000172476102728 ER PT J AU Bauer, BJ Lin, EK Lee, HJ Wang, H Wu, WL AF Bauer, BJ Lin, EK Lee, HJ Wang, H Wu, WL TI Structure and property characterization of low-k dielectric porous thin films SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Advances in Interconnect and Packaging Materials at the TMS Fall Meeting CY OCT 08-12, 2000 CL ST LOUIS, MISSOURI SP TMS DE porous thin film; x-ray reflectivity; small-angle neutron scattering; porosity; ion scattering; low-k dielectric material ID PORE-SIZE DISTRIBUTION; NANOPOROUS SILICA AB A novel methodology is developed that uses a combination of high energy ion scattering, x-ray reflectivity, and small angle neutron scattering to characterize the structure and properties of porous thin films. Ion scattering is used to determine the elemental composition of the film for absolute intensity calibration of the x-ray and neutron scattering techniques. X-ray reflectivity is used to measure the average electron density and film thickness. Small angle neutron scattering is used to determine the pore size, structure, and connectivity. Combining information from all three techniques, the film porosity and matrix material density can be uniquely determined. C1 NIST, Div Polymers, Elect Mat Grp, Gaithersburg, MD 20899 USA. RP Bauer, BJ (reprint author), NIST, Div Polymers, Elect Mat Grp, 100 Bur Dr,Stop 8541, Gaithersburg, MD 20899 USA. NR 9 TC 19 Z9 20 U1 0 U2 3 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD APR PY 2001 VL 30 IS 4 BP 304 EP 308 DI 10.1007/s11664-001-0035-x PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 422XK UT WOS:000168144400005 ER PT J AU Neuman, MJ Witting, DA Able, KW AF Neuman, MJ Witting, DA Able, KW TI Relationships between otolith microstructure, otolith growth, somatic growth and ontogenetic transitions in two cohorts of windowpane SO JOURNAL OF FISH BIOLOGY LA English DT Article DE otolith microstructure; validation; settlement; accessory growth centres; otolith growth; somatic growth ID EARLY-LIFE-HISTORY; PLEURONECTES-PLATESSA; PARALICHTHYS-DENTATUS; RHOMBOSOLEA-TAPIRINA; INCREMENT FORMATION; ATLANTIC MENHADEN; MORONE-SAXATILIS; SUMMER FLOUNDER; FISH OTOLITHS; STRIPED BASS AB Otolith increments in larval and juvenile windowpane Scophthalmus aquosus can provide an estimate of daily age for spring-spawned individuals held under summer conditions. Otolith increments for spring- and autumn-spawned individuals occurred at intervals >1 day under winter conditions. A significant decrease in the slope of the linear relationship between otolith size and somatic size at 40 mm L-S coincided with significant habitat, morphological and behavioural transitions, in smaller, field-captured windowpane belonging to spring- and autumn-spawned cohorts. the formation of accessory growth centres coincided with a transitional settlement period and the completion of eye migration (c. 8-20 mm L-S). Back-calculated growth rats estimates for spring-spawned windowpane were significantly faster than those Fur autumn-spawned windowpane and these differences could produce differential rates or survival for the two cohorts during the first year of life. (C) 2001 The Fisheries Society of the British Isles. 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, Sandy Hook, NJ 07732 USA. RP Neuman, MJ (reprint author), Rutgers State Univ, Marine Field Stn, Inst Marine & Coastal Sci, 800 C-O 132 Great Bay Blvd, Tuckerton, NJ 08087 USA. EM neuman@imcs.rutgers.edu NR 47 TC 33 Z9 35 U1 3 U2 10 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0022-1112 EI 1095-8649 J9 J FISH BIOL JI J. Fish Biol. PD APR PY 2001 VL 58 IS 4 BP 967 EP 984 DI 10.1006/jfbi.2000.1507 PG 18 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 419ZE UT WOS:000167978800006 ER PT J AU Norton, EC MacFarlane, RB Mohr, MS AF Norton, EC MacFarlane, RB Mohr, MS TI Lipid class dynamics during development in early life stages of shortbelly rockfish and their application to condition assessment SO JOURNAL OF FISH BIOLOGY LA English DT Article DE lipid class dynamics; early life stages; condition assessment; Sebastes jordani ID NUTRITIONAL CONDITION; ENGRAULIS-MORDAX; ANCHOVY LARVAE; CALIFORNIA; SEBASTES; GROWTH; STARVATION; HISTORY; GENUS; FISH AB Lipid class dynamics and the relationship between weight and length were analysed during early life stage (ELS) development in wild populations of shortbelly rockfish Sebastes jordani to investigate their utility in a condition or nutritional status assessment. Analyses from more than 3000 field-captured shortbelly rockfish indicated little variation in weight for a given length and provided limited application in the assessment of condition. The fractionation of total lipids into individual classes revealed trends in lipid metabolism throughout development. These trends were described best using a stage-specific regression model, since Sebastes show defined early life history transitions. Among developmental stages, triacylglycerols (TAG) and polar lipids (PL) were the dominant lipid classes and cholesterol (CHOL). sterol/wax esters. and nonesterified fatty acids were found in lower concentrations. In the preflexion stage, low concentrations and constant levels of TAG alone with the combined influence of endogenous and exogenous sources of energy compromised the use of TAG as an index of nutritional status. However. during flexion through juvenile stages, TAG levels increased indicating an accumulation of energy reserves with development, thus providing a valid indicator of nutritional status in later stages. Large fluctuations in PL concentrations during development suggested complex metabolism which may be due to changes in cell volume and cell membrane proliferation with development as well as catabolism. CHOL declined in larval stages, then remained constant with increasing size through the juvenile stage. negating its use as a normalizer for variations of mass in a TAG/CHOL ratio prior to juvenile transformation. This study provides the first documentation of lipid dynamics during early life stages following parturition in a marine viviparous teleost. C1 Santa Cruz Lab, SW Fisheries Sci Ctr, Natl Marine Fisheries Sci, Santa Cruz, CA 95060 USA. RP Norton, EC (reprint author), Santa Cruz Lab, SW Fisheries Sci Ctr, Natl Marine Fisheries Sci, 110 Shaffer Rd, Santa Cruz, CA 95060 USA. NR 41 TC 28 Z9 29 U1 1 U2 7 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD APR PY 2001 VL 58 IS 4 BP 1010 EP 1024 DI 10.1006/jfbi.2000.1509 PG 15 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 419ZE UT WOS:000167978800009 ER PT J AU Kenyon, M Cobb, JL Amar, A Song, D Zimmerman, NM Lobb, CJ Wellstood, FC AF Kenyon, M Cobb, JL Amar, A Song, D Zimmerman, NM Lobb, CJ Wellstood, FC TI Dynamics of a charged fluctuator in an Al-AlOx-Al single-electron transistor SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article ID STATES AB We report detailed observations of random-telegraph charge fluctuations in a two-junction Al-AlOx-Al single-electron transistor (SET) switched between two states, causing charge shifts of DeltaQ(o) = 0.1 +/- 0.025e on the SET's island. The transition rate out of each state was periodic in the gate voltage, varied non-monotonically with the device bias voltage, and was independent of the temperature about 0.3 K. We discuss two effects which could contribute to the behavior of the transition rates, including heating of the defect by the island conduction electrons and inelastic scattering between the defect and electrons flowing through the SET. C1 Univ Maryland, Dept Phys, Ctr Superconduct Res, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kenyon, M (reprint author), Univ Maryland, Dept Phys, Ctr Superconduct Res, College Pk, MD 20742 USA. RI Joint Quantum Institute, NIST/UMD/H-4494-2011 NR 20 TC 7 Z9 7 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD APR PY 2001 VL 123 IS 1-2 BP 103 EP 126 DI 10.1023/A:1017597515748 PG 24 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 435CM UT WOS:000168859900007 ER PT J AU Huffman, PR Brome, CR Butterworth, JS Dzhosyuk, SN Golub, R Lamoreaux, SK Mattoni, CEH McKinsey, DN Doyle, JM AF Huffman, PR Brome, CR Butterworth, JS Dzhosyuk, SN Golub, R Lamoreaux, SK Mattoni, CEH McKinsey, DN Doyle, JM TI Magnetically stabilized luminescent excitations in hexagonal boron nitride SO JOURNAL OF LUMINESCENCE LA English DT Article DE boron nitride; magnetic stabilization ID BAND-GAP; FILMS AB Magnetically stabilized luminescence is observed in hexagonal boron nitride. The luminescence is induced by absorption of cold neutrons and is in the visible region. In the absence of a magnetic field, the photon emission level is observed to decay over several hundred seconds. A fraction of this luminescence can be suppressed if the temperature is T less than or similar to0.6 K and the magnetic field is B less than or similar to 1.0 T. Subsequent to irradiation and suppression, luminescence can be induced by an increase in T or lowering of B. Possible explanations include stabilization of triplet states or the localization and stabilization of excitons. (C) 2001 Elsevier Science B,V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Harvard Univ, Cambridge, MA 02138 USA. Hahn Meitner Inst Kernforsch Berlin GmbH, D-1000 Berlin, Germany. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Huffman, PR (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. OI Huffman, Paul/0000-0002-2562-1378 NR 18 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 J9 J LUMIN JI J. Lumines. PD APR PY 2001 VL 92 IS 4 BP 291 EP 296 DI 10.1016/S0022-2313(01)00166-1 PG 6 WC Optics SC Optics GA 416WZ UT WOS:000167804500005 ER PT J AU Hastie, JW Bonnell, DW Schenck, PK AF Hastie, JW Bonnell, DW Schenck, PK TI Application of a new thermochemical measurement method for nuclear materials at temperatures beyond 3000 K SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 10th International Symposium on Themodynamics of Nuclear Materials CY AUG 06-11, 2000 CL HALIFAX, CANADA ID REFRACTORY MATERIALS; VAPORIZATION AB In processing and end-use environments, and particularly nuclear fission reactor excursions, inorganic materials can be subjected to temperatures where liquids and vapors are significant components of the materials system. Classical characterization and thermochemical methods fail at temperatures beyond about 3000 K, due to the reactivity of container materials. Use of a pulsed laser beam as a localized heat source avoids this limitation. Coupling laser heating with molecular beam sampling and mass- and optical-spectroscopy allows us to characterize the thermochemistry of liquid-vapor systems at temperatures of 3000-5000 K, pressures of 0.01-20 bar (1 bar = 10(5) Nm(-2)), and on a nanosecond order-of-magnitude time scale. Materials considered here include C, ZrO2, Y2O3 and HfO2. New approaches for temperature measurement and for pressure determination, using electron impact mass spectral data coupled with deposition rate measurements, are described. (C) 2001 Published by Elsevier Science B.V. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Hastie, JW (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 13 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD APR PY 2001 VL 294 IS 1-2 BP 175 EP 178 DI 10.1016/S0022-3115(01)00448-2 PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 425XZ UT WOS:000168318100031 ER PT J AU Zeisler, R Lamaze, GP Chen-Mayer, HH AF Zeisler, R Lamaze, GP Chen-Mayer, HH TI Coincidence and anti-coincidence measurements in prompt gamma neutron activation analysis with pulsed cold neutron beams SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB A novel approach is implemented to alleviate some persistent problems in neutron capture prompt gamma activation analysis (PGAA). Detection sensitivities of PGAA are often restricted by the following factors: poor signal to noise ratios, interferences from background signals, and, in some cases, overlapping energy lines from different origins, namely ultra short-lived decay lines interfering with prompt decay. Timing the gamma-ray acquisition with the actual capture events using a pulsed beam of cold neutrons allows discrimination between prompt and delayed emissions from a sample source as well as against background events. Coincidence gating selects the prompt gamma-ray emissions. Contributions of background capture gamma-rays are suppressed because of different flight times of neutrons to the sources of background radiation, providing a reduction in direct gamma-ray interferences. Anti-coincidence gating allows measurement of only decay radiation that originates from short-lived activated states of the nuclides after capture. Spectra of decaying nuclides are free of interfering prompt activities, as well as have lower continuum background from Compton scattering of high-energy prompt gamma-rays in the detector. The measurements provide the opportunity to use ultrashort half-life nuclides for analytical purposes, no sample transfer times are lost, and repetitive activation and counting cycles are achieved with the use of pulsed neutron beams. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Zeisler, R (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 9 TC 7 Z9 7 U1 1 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD APR PY 2001 VL 248 IS 1 BP 35 EP 38 DI 10.1023/A:1010609604827 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 423XU UT WOS:000168203700005 ER PT J AU Wu, ZY Inn, KGW Lin, ZC McMahon, CA AF Wu, ZY Inn, KGW Lin, ZC McMahon, CA TI Traceability of performance evaluation materials SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB One of the most critical elements of a performance evaluation (PE) program for radioactivity measurements is the traceability of the PE materials to the national standards. The requirements and criteria for the production of traceable environmental and radiobioassay PE materials have been defined by ANSI N42.22 and ANSI N13.30 standards. It is important to note that use of traceable source materials does not necessarily ensure the traceability of subsequently derived PE materials unless verification measurements exist in conjunction with the preparation processes. This paper describes the protocol currently used by NIST for the preparation and verification of air filter, acidified water, spilled soil, synthetic urine, and synthetic fecal PE materials for low-level radioactivity measurements. The process involves gravimetric dilutions and mixing of primary radionuclide NIST Standard Reference Materials (SRMs), addition of the derived master solution to sample matrices, and subsequent verification measurements. Several gamma-emitters were used to trace the gravimetric dilutions and spike addition through an unbroken chain of gamma comparison measurements. The massic activities of alpha- and beta-emitters in the diluted solutions and PE samples were also measured by radiochemical methods and compared with their gravimetric values. A correlation analysis demonstrated that the gamma emitters quantitatively followed Sr-90, U-238, Py-238 and Am-241 throughout the dilution and spiking and can be used as effective process monitors. The statistical results from t-tests. box plots, and normal probability tests suggested that traceability of radionuclides in the PE materials to their primary standards can be verified to within 1%, with an overall precision better than 2% (1s). C1 NIST, Phys Lab, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. RP Wu, ZY (reprint author), NIST, Phys Lab, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. NR 15 TC 9 Z9 9 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD APR PY 2001 VL 248 IS 1 BP 155 EP 161 DI 10.1023/A:1010663132568 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 423XU UT WOS:000168203700026 ER PT J AU Lin, ZC Inn, KGW Filliben, JJ AF Lin, ZC Inn, KGW Filliben, JJ TI An alternative statistical approach for interlaboratory comparison data evaluation SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article ID STANDARD REFERENCE MATERIAL; IRISH SEA; SEDIMENTS; INVENTORIES; DISPERSION AB Interlaboratory comparisons are an essential component of method validation, laboratory proficiency and equivalency evaluation, and standard reference material certification. The reliability of the results from interlaboratory comparison largely depends upon analyzing the data with appropriate statistical methods. Intercomparison data are often found to be non-normally distributed as a result of sample heterogeneity, uneven laboratory variance, and methodology bias. The statistical methods that require data normality are inappropriate for analyzing such skewed data. Instead of using data transformation or non-parametric methods, an alternative method which sets aside the assumption of data normality is utilized in the certification of new National Institute of Standards and Technology (NIST) Ocean Sediment Standard Reference Material (SRM4357). It first determines the best-fit distribution for the data, then calculates appropriate distributional mean and tolerance limits, and finally estimates the uncertainties for the derived statistics by bootstrap analysis. The method Nas applied to evaluate the data from the SRM intercomparison, and revealed homogeneity for natural radionuclides and inhomogeneity for anthropogenic radionuclides in the SRM. It was found that the data of natural radionuclides in the SRM are normally distributed. In contrast, the data of anthropogenic radionuclides, such as Sr-90, Cs-137, Pu-238, and ((239+240))Pu, are best fitted by Weibull distributions. The difference on data distributions for the two types of radionuclides is believed to be related to "hot" particles in the SRM. By determining the best-fit data distribution and applying bootstrap analysis, more reliable and realistic massic activity (Bq.kg(-1)) for anthropogenic radionuclides were certified in comparison to those obtained using data transformation and nonparametric methods. Although the developed method is computationally intensive, it provides a straightforward, rigorous procedure for computing the statistics that would otherwise be difficult to obtain when the data distribution form is complicated. With the help of advanced personal computers and use of the DataPlot software from NIST, this method becomes very practical and has enhanced interlaboratory comparison data studies and certification of the NIST standard reference materials. C1 NIST, Ionizing Radiat Div, Phys Lab, Gaithersburg, MD 20899 USA. NIST, Informat Technol Lab, Stat Engn Div, Gaithersburg, MD 20899 USA. RP Lin, ZC (reprint author), NIST, Ionizing Radiat Div, Phys Lab, Gaithersburg, MD 20899 USA. NR 14 TC 10 Z9 11 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD APR PY 2001 VL 248 IS 1 BP 163 EP 173 DI 10.1023/A:1010615200709 PG 11 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 423XU UT WOS:000168203700027 ER PT J AU McCurdy, DE Morton, JS Inn, KG AF McCurdy, DE Morton, JS Inn, KG TI Basic considerations for the preparation of performance testing materials as related to performance evaluation acceptance criteria SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB The preparation of performance testing (PT) materials for environmental and radiobioassay applications involves the use of natural matrix materials containing the analyte of interest the addition (spiking) of the analyte to a desired matrix (followed by blending for certain matrices) or a combination of the two. The distribution of the sample analyte concentration in a batch of PT samples will reflect the degree of heterogeneity of the analyte in the PT material and/or the reproducibility of the sample preparation process. Commercial and government implemented radioanalytical performance evaluation programs have a variety of acceptable performance criteria The performance criteria should take into consideration many parameters related to the preparation of the PT materials including the within and between sample analyte heterogeneity, the accuracy of the quantification of an analyte in the PT material and to what "known" value will a laboratory's result be compared. This manuscript discusses how sample preparation parameters affect the successful participation in performance evaluation (PE) programs having an acceptance criteria established as a percent difference from a "known" value or in PE programs using other acceptance criteria, such as the guidance provided in ANSI N42.22 and N13.30. C1 Duke Engn & Serv, Marlboro, MA USA. Natl Analyt Management Program, Dept Energy, Idaho Falls, ID USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP McCurdy, DE (reprint author), Duke Engn & Serv, Solomon Pond Pk,400 Donald Lynch Blvd, Marlboro, MA USA. NR 3 TC 1 Z9 1 U1 2 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD APR PY 2001 VL 248 IS 1 BP 185 EP 190 DI 10.1023/A:1010623418456 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 423XU UT WOS:000168203700030 ER PT J AU Inn, KGW Lin, ZC Wu, ZY McMahon, C Filliben, JJ Krey, P Feiner, M Liu, CK Holloway, R Harvey, J Larsen, IL Beasley, T Huh, CA Morton, S McCurdy, D Germain, P Handl, J Yamamoto, M Warren, B Bates, TH Holms, A Harvey, BR Popplewell, DS Woods, MJ Jerome, S Odell, KJ Young, P Croudace, I AF Inn, KGW Lin, ZC Wu, ZY McMahon, C Filliben, JJ Krey, P Feiner, M Liu, CK Holloway, R Harvey, J Larsen, IL Beasley, T Huh, CA Morton, S McCurdy, D Germain, P Handl, J Yamamoto, M Warren, B Bates, TH Holms, A Harvey, BR Popplewell, DS Woods, MJ Jerome, S Odell, KJ Young, P Croudace, I TI The NIST natural-matrix radionuclide standard reference material program for ocean studies SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB In 1977, the Low-level Working Group of the International Committee on Radionuclide Metrology met in Boston. MA (USA) to define the characteristics of a new set of environmental radioactivity reference materials. These reference materials were to provide the radiochemist with the same analytical challenges faced when assaying environmental samples. It was decided that radionuclide bearing natural materials should be collected from sites where there had been sufficient time for natural processes to redistribute the various chemically different species of the radionuclides. Over the succeeding years, the National Institute of Standards and Technology (NIST), in cooperation with other highly experienced laboratories, certified and issued a number of these as low-level radioactivity Standard Reference Materials (SRMs) for fission and activation product and actinide concentrations. The experience of certifying these SRMs has given NIST the opportunity to compare radioanalytical methods and learn of their limitations. NIST convened an international workshop in 1994 to define the natural-matrix radionuclide SRM needs for ocean studies. The highest priorities proposed at the workshop were for sediment, shellfish, seaweed, fish flesh and water matrix SRMs certified for mBq per sample concentrations of Sr-90, Cs-137 and Pu-239 + Pu-240. The most recent low-level environmental radionuclide SRM issued by NIST, Ocean Sediment (SRM 4357) has certified and uncertified values for the following 22 radionuclides: K-40 Sr-90, I-129, Cs-137, Eu-155, Pb-210, Po-210, Pb-212, Bi-214, Ra-226 Ra-228 Th-228, Th-230, Th-232, U-234, U-235, Np-237, U-238, Pu-238(,) Pu-239, + Pu-240, and Am-241. The uncertainties for a number of the certified radionuclides are non-symmetrical and relatively large because of the non-normal distribution of reported values. NIST is continuing its efforts to provide the ocean studies community with additional natural matrix radionuclide SRMs. The freeze-dried shellfish flesh matrix has been prepared and recently sent to participating laboratories for analysis and we anticipate receiving radioanalytical results in 2000. The research and development work at NIST produce well characterized SRMs that provide the world's environment-studies community with an important foundation component for radionuclide metrology. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. US Dept Energy, Environm Measurements Lab, New York, NY USA. US EPA, Las Vegas, NV 89193 USA. Int Technol Corp, Ridge, TN USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Oregon State Univ, Newport, OR 97365 USA. USDOE, Radiol & Environm Sci Lab, Idaho Falls, ID USA. Ctr Etud Nucl, Lab Radioecol Marine, Fontenay Aux Roses, France. Niedersachs Inst Radiookol, Hannover, Germany. Kanazawa Univ, Kanazawa, Ishikawa 920, Japan. Atom Weapons Estab, Aldermaston, England. British Nucl Fuels Plc, Sellafield, England. Lab Govt Chemist, Teddington TW11 0LY, Middx, England. Minist Agr Fisheries & Food, Lowestoft, Suffolk, England. Natl Radiol Protect Board, Didcot OX11 0RQ, Oxon, England. Natl Phys Lab, Teddington TW11 0LW, Middx, England. Nucl Elect, Gravesend, England. S Scotland Elect Board, Hunterston, Scotland. Southhampton Oceanog Ctr, Southampton, Hants, England. RP Inn, KGW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Huh, Chih-An/N-4610-2013; OI Croudace, Ian/0000-0003-1547-5650 NR 7 TC 10 Z9 11 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD APR PY 2001 VL 248 IS 1 BP 227 EP 231 DI 10.1023/A:1010635705252 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 423XU UT WOS:000168203700036 ER PT J AU James, WD Zeisler, R AF James, WD Zeisler, R TI Uptake of oxygen in a coal standard reference material (R) determined by fast (14-MeV) neutron activation analysis SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB A fast (14-MeV) neutron activation analysis procedure was employed to directly measure mass fractions of oxygen in coal samples. The procedure demonstrated sufficient precision and accuracy to determine a relative change of about 5% or more, in the oxygen mass fraction of about 12%. The procedure was applied to test samples of the newly developed SRM 1632c Trace Elements in Coal (Bituminous). The samples had been stored at three conditions: in liquid nitrogen vapor and at room temperature in the original containers packaged under argon, and for accelerated aging at 50 degreesC open to air. Following six months storage increments, duplicate samples of each of twelve bottles of the SRM were measured for each storage condition. In addition each sample was processed through ten separate analytical runs yielding a total of some 720 measurements per storage duration. Oxygen was determined by comparison to a primary standard potassium dichromate and the accuracy of the method was assessed through the analysis of replicate samples of three reference materials that are certified for oxygen content. The initial 6-months test period indicated uptake of oxygen in the open-air storage. C1 Texas A&M Univ, Ctr Chem Characterizat & Anal, College Stn, TX 77843 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP James, WD (reprint author), Texas A&M Univ, Ctr Chem Characterizat & Anal, College Stn, TX 77843 USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD APR PY 2001 VL 248 IS 1 BP 233 EP 237 DI 10.1023/A:1010639822090 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 423XU UT WOS:000168203700037 ER PT J AU Currie, LA Klouda, GA AF Currie, LA Klouda, GA TI Detection and quantification capabilities for Kr-85 with the NIST low-level gas counting system: Impacts of instrumental and environmental backgrounds SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB Among the most important, conservative geochemical tracers are the long-lived isotopes of krypton, Kr-81 and Kr-85. Following a brief review of the metrology and applications of these radionuclides, we focus on the low-level measurement of the 10.8 year fission product Kr-85, in connection with its use for studying atmospheric transport and short term (decadal) atmosphere-ocean exchange and mixing. Special challenges for the study of 85Kr in the environment are: (1) reducing detection/quantification limits to mBq levels, to minimize the need for costly (large) atmospheric and marine samples, where current levels are ca. 1.4 Bq.m(-3) (northern troposphere) and 0.08 mBq.kg(-1) (surface ocean water); and (2) designing a protocol that accounts for the influence of both instrumental and environmental backgrounds and their variability. The capability of the NIST enhanced low-level gas counting system to meet these challenges was demonstrated theoretically and experimentally, showing that ambient Kr-85 can be quantified in just 1.5 1 air or 25 1 seawater with 2000 min paired counting periods. C1 NIST, Gaithersburg, MD 20899 USA. RP Currie, LA (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 15 TC 4 Z9 4 U1 0 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD APR PY 2001 VL 248 IS 1 BP 239 EP 246 DI 10.1023/A:1010691922999 PG 8 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 423XU UT WOS:000168203700038 ER PT J AU Abdulagatov, IM Bazaev, EA Bazev, AR Rabezkii, MG AF Abdulagatov, IM Bazaev, EA Bazev, AR Rabezkii, MG TI PVTx measurements for dilute water plus n-hexane mixtures in the near-critical and supercritical regions SO JOURNAL OF SUPERCRITICAL FLUIDS LA English DT Article DE PVTx relation; critical point; excess molar volume; n-hexane; partial molar volume; supercritical water ID SOLVENTS CRITICAL-POINT; VIRIAL-COEFFICIENTS; PHASE-EQUILIBRIA; HIGH-PRESSURES; VOLUMETRIC PROPERTIES; AQUEOUS MIXTURES; BINARY-SYSTEMS; DEGREES-C; + WATER; TEMPERATURES AB The PVTx relationship of four binary dilute (water + n-hexane) mixtures (0.0021, 0.0050, 0.0850 and 0.0138 mole fraction of n-hexane) were measured with a constant-volume method. Measurements were made at five near-critical and supercritical temperatures of pure water: 643.05, 645.05, 647.05, 649.05 and 651.05 K. The range of pressures was from 8 to 35 MPa. The total uncertainty of density, pressure, concentration, and temperature measurements were estimated to be less than +/-0.2%, +/- 5 kPa, 0.001 mole fraction, and 10 mK, respectively. The derived PVTx data have been differentiated to yield infinite dilution partial molar volumes (V) over bar (infinity)(2). Asymptotic properties for V,l along the critical isotherm-isobar of the pure solvent (water) are experimentally studied. We show that PVTx measurements for the dilute water + n-hexane mixture confirm the non-classical power-law behavior of (V) over bar (infinity)(2) along the experimental path of constant T-C-P-C with a critical exponent of 0.79. The values of the Krichevskii parameter of 96.4 MPa for the dilute water + n-hexane mixture was estimated from PVTx measurements and compared with values calculated from the initial slopes of the T-C-x and P-C-x critical lines and the slope of the vapor-pressure P-S-T-S curve at the pure solvent critical point. The excess molar volumes of the mixture near the critical point of pure water are calculated using measured PVTs properties for mixtures and pure components. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Dagestan Sci Ctr, Inst Geothermal Res, Makhachkala 367030, Russia. RP Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80305 USA. EM ilmutdin@boulder.nist.gov NR 68 TC 23 Z9 23 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0896-8446 EI 1872-8162 J9 J SUPERCRIT FLUID JI J. Supercrit. Fluids PD APR PY 2001 VL 19 IS 3 BP 219 EP 237 DI 10.1016/S0896-8446(00)00100-5 PG 19 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 421UF UT WOS:000168081400001 ER PT J AU Kanematsu, W Sando, M Ives, LK Marinenko, R Quinn, GD AF Kanematsu, W Sando, M Ives, LK Marinenko, R Quinn, GD TI Dye impregnation method for revealing machining crack geometry SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 101st Annual Meeting of the American-Ceramic-Society CY APR 25-28, 1999 CL INDIANAPOLIS, INDIANA SP Amer Ceram Soc ID SILICON-NITRIDE; RESIDUAL-STRESSES; SIALON CERAMICS; GROUND CERAMICS; STRENGTH; FRACTURE; COMPOSITES; PARAMETERS; TOUGHNESS; BEHAVIOR AB The palladium nitrate dye penetrant method for revealing surface microcracks was investigated and applied to display the geometry of machining cracks in silicon nitride flexure test specimens. This method used elemental mapping with an electron probe microanalyzer to detect the presence of the dye and, thereby, display the crack geometry. A previously used bending method and a method developed in this study in which the specimen surface is exposed to the dye under pressure were used to facilitate dye penetration. Prior to applying the method to study machining cracks, carefully controlled Knoop indentation cracks introduced into flexure specimens were used to verify penetration of the dye to the crack tip. During these experiments it was found that the palladium nitrate dye resulted in a reduction in flexure strength, which, on further study, was attributed to the dilute nitric acid solution used to formulate the dye. Exposure to carbon tetrafluoride plasma etching prior to applying the pressurized dye method also resulted in a detectable decrease in flexure strength. Although there was clear evidence that exposure to dye and plasma etching resulted in a small but measurable decrease in flexure strength for the silicon nitride material studied, there was no detectable change in observed crack geometry. The reduction in flexure strength was apparently caused by a decrease in resistance to initiate crack propagation. It was concluded that the palladium nitrate dye method is an accurate and useful means for determining the geometry of small, otherwise difficult to observe surface microcracks, Nevertheless, caution should be exercised with the use of this method during strength measurements. When applied to machining cracks, the complex nature of these shallow, elongated, sometimes joining cracks was unambiguously revealed. C1 Natl Ind Res Inst Nagoya, Nagoya, Aichi 4628510, Japan. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kanematsu, W (reprint author), Natl Ind Res Inst Nagoya, Nagoya, Aichi 4628510, Japan. NR 42 TC 11 Z9 11 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD APR PY 2001 VL 84 IS 4 BP 795 EP 800 DI 10.1111/j.1151-2916.2001.tb00743.x PG 6 WC Materials Science, Ceramics SC Materials Science GA 421BM UT WOS:000168042300017 ER PT J AU Blanchard, TW Santiago, NT Lipscomb, TP Garber, RL McFee, WE Knowles, S AF Blanchard, TW Santiago, NT Lipscomb, TP Garber, RL McFee, WE Knowles, S TI Two novel alphaherpesviruses associated with fatal disseminated infections in Atlantic bottlenose dolphins SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE Bottlenose dolphin; heart; herpesvirus; inclusions; lymphoid necrosis; syncytial cells; thymus; Tursiops truncatus ID POLYMERASE-CHAIN-REACTION; GULF-OF-MEXICO; DELPHINAPTERUS-LEUCAS; NOSED DOLPHINS; DERMATITIS AB Two immature female bottlenose dolphins (Tursiops truncatus) were found stranded on the Atlantic coast of the USA. Necropsy and histopathologic examination of both dolphins demonstrated acute necrotizing lesions in multiple organ systems. Commonly seen in these lesions were cells with enlarged nuclei that contained single 4 to 6 mum diameter homogeneous eosinophilic inclusion bodies that were often surrounded by a clear halo. Ultrastructural examination revealed that intranuclear inclusions contained 90 to 110 nm diameter viral particles with electron-dense cores and hexagonal profiles. Viral particles were also present in the cytoplasm, and these were surrounded by variable electron-dense envelopes. Enveloped virions were 140 nm in diameter. Polymerase chain reactions targeting the DNA polymerase and terminase genes of herpesviruses were carried out on unfixed tissues of both animals, and analysis of the DNA products indicated the presence of two novel alphaherpesviruses. The gross, histologic, ultrastructural, and molecular genetic findings indicate disseminated herpesviral infections, and support the conclusion that the alphaherpesviruses caused the deaths of the two dolphins. This is the first report of disseminated herpesviral infection in cetaceans. C1 Armed Forces Inst Pathol, Dept Vet Pathol, Washington, DC 20306 USA. PathoGenesis Corp, Seattle, WA 98119 USA. NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Charleston, SC 29412 USA. Cooperat Oxford Lab, Dept Nat Resources, Oxford, MD 21654 USA. RP Blanchard, TW (reprint author), Armed Forces Inst Pathol, Dept Vet Pathol, Washington, DC 20306 USA. OI Knowles, Susan/0000-0002-0254-6491 NR 17 TC 31 Z9 36 U1 1 U2 2 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 USA SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD APR PY 2001 VL 37 IS 2 BP 297 EP 305 PG 9 WC Veterinary Sciences SC Veterinary Sciences GA 421RP UT WOS:000168077600010 PM 11310880 ER PT J AU Walker, WA AF Walker, WA TI Geographical variation of the parasite, Phyllobothrium delphini (Cestoda), in Dall's porpoise, Phocoenoides dalli, in the northern North Pacific, Bering Sea, and sea of Okhotsk SO MARINE MAMMAL SCIENCE LA English DT Article DE Dall's porpoise; Phocoenoides dalli; parasitism; Phyllobothrium delphini; biological tags; geographical variation; elasmobranchs; blue shark; prionace glauca ID EASTERN TROPICAL PACIFIC; INDICATORS; STENELLA AB Prevalence of the larval cestode, Phyllobothrium delphini, was estimated from 2,445 Dall's porpoise, Phocoenoides dalli, from the incidental take of the Japanese high seas salmon drift-net fishery in the northwestern North Pacific Ocean, Bering Sea, and a local hand harpoon fishery in the southern Sea of Okhotsk. Prevalence of P. delphini was 22.7% in the northwestern North Pacific Ocean and 1.4% in the Bering Sea. This parasite was not found in the southern Sea of Okhotsk. Geographical differences in the prevalence of P. delphini may be due, at least in part, to regional differences in abundance of elasmobranchs known to feed on marine mammals and suspected as hosts of the parasite. Estimated intensity of infection of individual porpoises by P. delphini was low (estimated mean intensity of 3.5 plerocercoids per animal). This is a low intensity of infection compared to other species of small cetaceans studied and may be due to both differences in regional abundance of elasmobranchs and the comparatively short life span of P, dalli. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Walker, WA (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, 7600 Sand Point Way,NE, Seattle, WA 98115 USA. EM mindwalk@msn.com NR 32 TC 6 Z9 6 U1 1 U2 9 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0824-0469 EI 1748-7692 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 2001 VL 17 IS 2 BP 264 EP 275 DI 10.1111/j.1748-7692.2001.tb01270.x PG 12 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 415JT UT WOS:000167718700003 ER PT J AU Huber, HR Jeffries, SJ Brown, RF DeLong, RL VanBlaricom, G AF Huber, HR Jeffries, SJ Brown, RF DeLong, RL VanBlaricom, G TI Correcting aerial survey counts of harbor seals (Phoca vitulina richardsi) in Washington and Oregon SO MARINE MAMMAL SCIENCE LA English DT Article DE harbor seal; Phoca vitulina richardsi; census methods; population estimate; aerial survey; radio-tagging; correction factor ID SAN-MIGUEL-ISLAND; COMMON SEAL; CALIFORNIA; MOVEMENTS; PATTERNS AB Aerial surveys of harbor seals on land produce only a minimum assessment of the population; a correction factor to account for the missing animals is necessary to estimate total abundance. In 1991 and 1992, VHF radio tags were deployed on harbor seals (n = 124) at six sites in Washington and Oregon. During aerial surveys a correction factor to account for seals in the water was determined from the proportion of radio-tagged seals on shore during the pupping season. This proportion ranged from 0.54 to 0.74. Among the six sites there was no significant difference in the proportion of animals on shore nor was there a difference in age/sex categories of seals on shore between sites. The pooled correction factor for determining total population abundance was 1.53. An additional 32 seals were radio tagged in 1993 at one of the sites used in 1991. Comparing data from the two years we found no interannual variation. Aerial surveys of all known harbor haul-out sites in Washington (n = 319) and Oregon (n = 68) were flown during the peak of the pupping season, 1991-1993. The Washington and Oregon harbor seal population was divided into two stocks based on pupping phenology, morphometics, and genetics. Mean counts for the Washington inland stock were 8,710 in 1991, 9,018 in 1992, and 10,092 in 1993 Oregon and Washington coastal stock mean counts were 18,363 in 1991, 18,556 in 1992, and 17,762 in 1993. Multiplying the annual count by the correction factor yielded estimates of harbor seal abundance in the Washington inland stock of 13,326 (95% CI = 11,637-15,259) for 1991, 13,798 (95% CI = 11,980-15,890) for 1992, and 15,440 (95% CI = 13,382-17,814) for 1993. In the Oregon and Washington coastal stock the corrected estimate of harbor seal abundance was 28,094 (95% CI = 24,697-31,960) in 1991, 28,391 (95% CI = 24,847-32,440) for 1992, and 27,175 (95% CI = 23,879-30,926) for 1993. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. Washington Dept Fish & Wildlife, Tacoma, WA 98498 USA. Oregon Dept Fish & Wildlife, Wildlife Divers Program, Corvallis, OR 97330 USA. Univ Washington, Sch Fisheries, Washington Cooperat Fis & Wildlife Res Unit, US Geol Survey,Biol Resources Div, Seattle, WA 98105 USA. RP Huber, HR (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, 7600 Sand Point Way,NE, Seattle, WA 98115 USA. NR 41 TC 41 Z9 44 U1 4 U2 12 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 2001 VL 17 IS 2 BP 276 EP 293 DI 10.1111/j.1748-7692.2001.tb01271.x PG 18 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 415JT UT WOS:000167718700004 ER PT J AU Laidre, KL Jameson, RJ DeMaster, DP AF Laidre, KL Jameson, RJ DeMaster, DP TI An estimation of carrying capacity for sea otters along the California coast SO MARINE MAMMAL SCIENCE LA English DT Article DE southern sea otter; Enhydra lutris nereis; carrying capacity; GIS; California ID PATTERNS AB Carrying capacity (K) for the California sea otter (Enhydra lutris nereis) was estimated as a product of the density of sea otters at equilibrium within a portion of their existing range and the total area of available habitat. Equilibrium densities were determined using the number of sea otters observed during spring surveys in 1994, 1995, and 1996 in each of three habitat types where sea otters currently exist. Potential sea otter habitat was defined as from the California coastline to the 40-m isobath and classified as rocky, sandy, or mixed habitat according to the amount of kelp and rocky substrate in the area. The amount of habitat available to sea otters in California was estimated using a Geographic Information Systems (GIS) program. The estimated mean number of sea otters that could be supported by the marine environment to a depth of 40 m in California was 15,941 (95% CI 13,538-18,577). The GIS-based approach incorporated detailed bathymetric contours, produced repeatable and accurate estimates, and served as an innovative method of measuring sea otter habitat. We believe the approach described in this paper represents the best available information on how a sea otter population at equilibrium would be distributed along the California coast. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. US Geol Survey, Western Ecol Res Ctr, Corvallis, OR 97333 USA. RP Laidre, KL (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 22 TC 14 Z9 14 U1 3 U2 18 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 2001 VL 17 IS 2 BP 294 EP 309 DI 10.1111/j.1748-7692.2001.tb01272.x PG 16 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 415JT UT WOS:000167718700005 ER PT J AU Kinzey, D Gerrodette, T AF Kinzey, D Gerrodette, T TI Conversion factors for binocular reticles SO MARINE MAMMAL SCIENCE LA English DT Article C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Kinzey, D (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. NR 4 TC 9 Z9 11 U1 0 U2 2 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 2001 VL 17 IS 2 BP 353 EP 361 DI 10.1111/j.1748-7692.2001.tb01276.x PG 9 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 415JT UT WOS:000167718700009 ER PT J AU Roberts, SP DeMaster, DP AF Roberts, SP DeMaster, DP TI Pinniped survival in captivity: Annual survival rates of six species SO MARINE MAMMAL SCIENCE LA English DT Article ID DOLPHINS C1 Natl Marine Fisheries Serv, Off Protected Resources, Silver Spring, MD 20910 USA. NOAA, Natl Marine Fisheries Serv, Natl Mammal Lab, Seattle, WA 98115 USA. RP Roberts, SP (reprint author), Natl Marine Fisheries Serv, Off Protected Resources, Floor 13,1315 East West Highway, Silver Spring, MD 20910 USA. NR 7 TC 0 Z9 1 U1 1 U2 16 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 2001 VL 17 IS 2 BP 381 EP 387 DI 10.1111/j.1748-7692.2001.tb01280.x PG 7 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 415JT UT WOS:000167718700013 ER PT J AU Pyle, P Long, DJ Schonewald, J Jones, RE Roletto, J AF Pyle, P Long, DJ Schonewald, J Jones, RE Roletto, J TI Historical and recent colonization of the South Farallon Islands, California, by northern fur seals (Callorhinus ursinus) SO MARINE MAMMAL SCIENCE LA English DT Article ID SAN-MIGUEL ISLAND; GUADALUPE C1 Point Reyes Bird Observ, Stinson Beach, CA 94970 USA. Calif Acad Sci, Dept Ornithol & Mammol, San Francisco, CA 94118 USA. Univ Calif Berkeley, Museum Vertebrate Zool, Berkeley, CA 94720 USA. Gulf Farallones Natl Marine Sanctuary, San Francisco, CA 94123 USA. RP Pyle, P (reprint author), Point Reyes Bird Observ, 4990 Shoreline Hwy, Stinson Beach, CA 94970 USA. NR 25 TC 7 Z9 8 U1 0 U2 5 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 2001 VL 17 IS 2 BP 397 EP 402 DI 10.1111/j.1748-7692.2001.tb01282.x PG 6 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 415JT UT WOS:000167718700015 ER PT J AU Jones, BA DeMaster, DP AF Jones, BA DeMaster, DP TI Survivorship of captive southern sea otters SO MARINE MAMMAL SCIENCE LA English DT Article ID SURVIVAL C1 Prescott Coll, Ctr Cultural & Ecol Studies, Bahia De Kino 83340, Sonora, Mexico. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Narl Marine Mammal Lab, Seattle, WA 98115 USA. RP Jones, BA (reprint author), Prescott Coll, Ctr Cultural & Ecol Studies, APDO 69, Bahia De Kino 83340, Sonora, Mexico. NR 9 TC 0 Z9 0 U1 1 U2 7 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 2001 VL 17 IS 2 BP 414 EP 418 DI 10.1111/j.1748-7692.2001.tb01284.x PG 5 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 415JT UT WOS:000167718700017 ER PT J AU Clapham, P AF Clapham, P TI Why do baleen whales migrate? A response to Corkeron and Connor SO MARINE MAMMAL SCIENCE LA English DT Letter ID MEGAPTERA-NOVAEANGLIAE; HUMPBACK WHALE; ORCINUS-ORCA; WEST-INDIES C1 NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Clapham, P (reprint author), NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 34 TC 28 Z9 30 U1 3 U2 33 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 2001 VL 17 IS 2 BP 432 EP 436 DI 10.1111/j.1748-7692.2001.tb01289.x PG 5 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 415JT UT WOS:000167718700021 ER PT J AU Ford, MJ AF Ford, MJ TI Molecular evolution of transferrin: Evidence for positive selection in salmonids SO MOLECULAR BIOLOGY AND EVOLUTION LA English DT Article DE positive selection; likelihood; disease resistance; transferrin; salmon; evolution ID SEQUENCE-ANALYSIS; NUCLEOTIDE-SEQUENCE; BACTERIAL TRANSFERRIN; ONCORHYNCHUS-KISUTCH; DNA-SEQUENCES; LACTOFERRIN; CLONING; CDNA; IRON; PHYLOGENY AB Transferrins are iron-binding proteins that are involved in iron storage and resistance to bacterial disease. Previous work has shown that nonsynonymous-to-synonymous-site substitution ratios (d(n)/d(s) ratios) between transferrin genes from some salmonid species were significantly greater than 1.0, providing evidence for positive selection at the transferrin gene. The purpose of the current study was to put these earlier results in a broader evolutionary context by examining variation among 25 previously published transferrin sequences from fish, amphibians, and mammals. The results of the study show that evidence for positive selection at transferrin is limited to salmonids-d(n)/d(s) ratios estimated for nonsalmonid lineages were generally less than 1.0. Within the salmonids, similar to 13% of the transferrin codon sites are estimated to be subject to positive selection, with an estimated d(n)/d(s) ratio of similar to7. The three-dimensional locations of some of the selected sites were inferred by comparing these sites to homologous sites in the bovine lactoferrin crystallographic structure. The selected sites generally fall on the outside of the molecule, within and near areas that are bound by transferrin-binding proteins from human pathogenic bacteria. The physical locations of sites estimated to be subject to positive selection support previous speculation that competition for iron from pathogenic bacteria could be the source of positive selection. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98112 USA. RP Ford, MJ (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. RI Ford, Michael/K-3147-2012 NR 48 TC 75 Z9 81 U1 2 U2 5 PU SOC MOLECULAR BIOLOGY EVOLUTION PI LAWRENCE PA PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0737-4038 J9 MOL BIOL EVOL JI Mol. Biol. Evol. PD APR PY 2001 VL 18 IS 4 BP 639 EP 647 PG 9 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA 418NM UT WOS:000167898300021 PM 11264416 ER PT J AU King, TL Kalinowski, ST Schill, WB Spidle, AP Lubinski, BA AF King, TL Kalinowski, ST Schill, WB Spidle, AP Lubinski, BA TI Population structure of Atlantic salmon (Salmo salar L.): a range-wide perspective from microsatellite DNA variation SO MOLECULAR ECOLOGY LA English DT Article DE biogeography; fisheries management; microsatellite; phylogeography; population genetics; Salmonidae ID GENETIC-VARIATION; NORTH-AMERICAN; MITOCHONDRIAL-DNA; NATURAL-POPULATIONS; PHYLOGENETIC TREES; PROTEIN VARIATION; HATCHERY STOCKS; RIVER; DIVERSITY; IRELAND AB Atlantic salmon (n = 1682) from 27 anadromous river populations and two nonanadromous strains ranging from south-central Maine, USA to northern Spain were genotyped at 12 microsatellite DNA loci. This suite of moderate to highly polymorphic loci revealed 266 alleles (5-37/locus) range-wide. Statistically significant allelic and genotypic heterogeneity was observed across loci between all but one pairwise comparison. Significant isolation by distance was found within and between North American and European populations, indicating reduced gene flow at all geographical scales examined. North American Atlantic salmon populations had fewer alleles, fewer unique alleles (though at a higher frequency) and a shallower phylogenetic structure than European Atlantic salmon populations. We believe these characteristics result from the differing glacial histories of the two continents, as the North American range of Atlantic salmon was glaciated more recently and more uniformly than the European range. Genotypic assignment tests based on maximum-likelihood provided 100% correct classification to continent of origin and averaged nearly 83% correct classification to province of origin across continents. This multilocus method, which may be enhanced with. additional polymorphic loci, provides fishery managers the highest degree of correct assignment to management unit of any technique currently available. C1 US Geol Survey, Biol Resources Div, Leetown Sci Ctr, Aquat Ecol Lab, Kearneysville, WV 25430 USA. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98112 USA. US Geol Survey, Biol Resources Div, Leetown Sci Ctr, Natl Fish Hlth Res Lab, Kearneysville, WV 25430 USA. Johnson Control World Serv, Lafayette, LA 70506 USA. RP King, TL (reprint author), US Geol Survey, Biol Resources Div, Leetown Sci Ctr, Aquat Ecol Lab, 1700 Leetown Rd, Kearneysville, WV 25430 USA. RI Kalinowski, Steven/A-7607-2008; OI Schill, William/0000-0002-9217-984X NR 64 TC 160 Z9 166 U1 3 U2 28 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD APR PY 2001 VL 10 IS 4 BP 807 EP 821 DI 10.1046/j.1365-294X.2001.01231.x PG 15 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 428RH UT WOS:000168455500001 PM 11348491 ER PT J AU Backus, S Bartels, R Thompson, S Dollinger, R Kapteyn, HC Murnane, MM AF Backus, S Bartels, R Thompson, S Dollinger, R Kapteyn, HC Murnane, MM TI High-efficiency, single-stage 7-kHz high-average-power ultrafast laser system SO OPTICS LETTERS LA English DT Article ID SAPPHIRE REGENERATIVE AMPLIFIER; SOFT X-RAYS; TI-SAPPHIRE; FEMTOSECOND PULSES; REPETITION-RATE; 1 KHZ; GENERATION; AMPLIFICATION; COMPRESSION; LEVEL AB We demonstrate a simple and practical single-stage ultrafast laser amplifier system that operates at a repetition frequency from 1 to 10 kHz, with millijoule pulse energy and as much as 13 FV of average power. The repetition rate can be adjusted continuously from 1 to 1D kHz by new all-solid-state pump laser technology. This is to our knowledge the highest average power ever obtained from a single-stage ultrafast laser amplifier system. This laser Will significantly increase the average power and the repetition rate that is easily accessible for high-field experiments such as coherent x-ray generation or for laser-synchrotron studies. (C) 2001 Optical Society of America. C1 Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Backus, S (reprint author), Natl Inst Stand & Technol, JILA, 325 Broadway, Boulder, CO 80309 USA. RI Backus, Sterling/C-2506-2008; Kapteyn, Henry/H-6559-2011 OI Kapteyn, Henry/0000-0001-8386-6317 NR 25 TC 95 Z9 95 U1 0 U2 8 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 APR 1 PY 2001 VL 26 IS 7 BP 465 EP 467 DI 10.1364/OL.26.000465 PG 3 WC Optics SC Optics GA 416HL UT WOS:000167774200023 PM 18040355 ER PT J AU Bryant, GW Jaskolski, W AF Bryant, GW Jaskolski, W TI Designing nanocrystal nanosystems: Quantum-dot quantum-wells to quantum-dot solids SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT International Conference on Semiconductor Quantum Dots (QD2000) CY JUL 31-AUG 03, 2000 CL TECHN UNIV MUNICH, MUNICH, GERMANY HO TECHN UNIV MUNICH ID CDS/HGS/CDS; PHOTOPHYSICS; COLLOIDS; CDS AB To design nanocrystalline nanosystems, a theory for nanocrystals is needed which can be: applied to nanocrystals with atomic-scale variations in composition, structure and shape. We present an empirical tight-binding theory for nanocrystal heteronanostructures. Electronic structure and optical absorption spectra are obtained for CdS/HgS/CdS and ZnS/CdSZnS quantum-dot quantum-well nanocrystals. Comparison with experiment shows that tight-binding theory provides a good description of nanosystems with monolayer variations in composition. Issues for designing nanocrystal heteronanostructures are discussed. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. UMK, Inst Fizyki, Torun, Poland. RP Bryant, GW (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Jaskolski, Wlodzimierz/D-1318-2014 OI Jaskolski, Wlodzimierz/0000-0003-4814-1876 NR 14 TC 26 Z9 26 U1 0 U2 3 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD APR PY 2001 VL 224 IS 3 BP 751 EP 755 DI 10.1002/(SICI)1521-3951(200104)224:3<751::AID-PSSB751>3.3.CO;2-C PG 5 WC Physics, Condensed Matter SC Physics GA 427XU UT WOS:000168432100028 ER PT J AU Rahmani, A Bryant, GW AF Rahmani, A Bryant, GW TI Modification of spontaneous emission of quantum dots: Purcell effect in semiconductor microcavities SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT International Conference on Semiconductor Quantum Dots (QD2000) CY JUL 31-AUG 03, 2000 CL TECHN UNIV MUNICH, MUNICH, GERMANY HO TECHN UNIV MUNICH ID DISCRETE-DIPOLE APPROXIMATION; SCATTERING; ATOMS; RADIATION; GRAINS; FIELD AB We study the spontaneous emission of a quantum dot embedded in a cavity;. Purcell and local-field effects are investigated using the coupled dipole method and a comparison with a continuous medium approach is presented. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Bryant, GW (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Rahmani, Adel/G-6406-2011 NR 13 TC 3 Z9 3 U1 0 U2 3 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD APR PY 2001 VL 224 IS 3 BP 807 EP 810 DI 10.1002/(SICI)1521-3951(200104)224:3<807::AID-PSSB807>3.0.CO;2-D PG 4 WC Physics, Condensed Matter SC Physics GA 427XU UT WOS:000168432100037 ER PT J AU Deng, L Payne, MG Garrett, WR AF Deng, L Payne, MG Garrett, WR TI Four-wave mixing with short pulses and optimized atomic coherence SO PHYSICAL REVIEW A LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; NONLINEAR FREQUENCY-CONVERSION; AMPLIFICATION; REFRACTION; GENERATION; INVERSION; SYSTEMS; QUANTUM; INDEX AB We present a lime-dependent calculation for four-wave mixing using a combination of long, short, and time delayed laser pulses in the context of electromagnetically induced transparency. Two transform limited nanosecond lasers are used to create a highly coherent mixture of the ground state and an excited state via a two-photon process. Once the induced transparency is established, a laser with short pulse length is injected after a suitable delay to generate four-wave mixing. We show that the wave mixing process is phase matched for all detunings, and with appropriately selected atomic coherence and populations, near 100% photon flux conversion efficiency can be obtained, independent of the intensity of the short pulse laser. In addition, we show that for small detunings for the short pulse laser, the four-wave mixing field travels with the speed of light in vacuum and suffers no pulse distortion even though the medium is highly dispersive at the frequency of the generated wave. These advantages open a door for future applications of the scheme for highly efficient, very stable UV generation. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Chem Phys Sect, Oak Ridge, TN 37831 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 21 TC 5 Z9 6 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 APR PY 2001 VL 63 IS 4 AR 043811 DI 10.1103/PhysRevA.63.043811 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 422AG UT WOS:000168095300117 ER PT J AU Jentschura, UD Mohr, PJ Soff, G AF Jentschura, UD Mohr, PJ Soff, G TI Electron self-energy for the K and L shells at low nuclear charge SO PHYSICAL REVIEW A LA English DT Article ID ORDER BINDING CORRECTIONS; STRONG COULOMB FIELD; 1S-2S TRANSITION FREQUENCY; HYDROGEN-LIKE ATOMS; LITHIUM-LIKE ATOMS; LAMB-SHIFT; RECOIL CORRECTIONS; STATE ENERGY; ALPHA-Z; LOGARITHMS AB A nonperturbative numerical evaluation of the one-photon electron self-energy for the K- and L-shell states of hydrogenlike ions with nuclear charge numbers Z = 1 to 5 is described. Our calculation for the S-1(1/2) state has a numerical uncertainty of 0.8 Hz in atomic hydrogen, and for the L-shell states (2S(1/2), 2P(1/2), and 2P(3/2)) the numerical uncertainty is 1.0 Hz. The method of evaluation for the ground state and for the excited states is described in detail. The numerical results are compared to results based on known terms in the expansion of the self-energy in powers of Z alpha. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Tech Univ Dresden, Inst Theoret Phys, D-01062 Dresden, Germany. RP Jentschura, UD (reprint author), Natl Inst Stand & Technol, Mail Stop 8401, Gaithersburg, MD 20899 USA. EM jentschura@physik.tu-dresden.de; mohr@nist.gov; soff@physik.tu-dresden.de NR 70 TC 48 Z9 48 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 2001 VL 63 IS 4 AR 042512 DI 10.1103/PhysRevA.63.042512 PG 19 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 422AG UT WOS:000168095300051 ER PT J AU Muller, D Cornell, EA Prevedelli, M Schwindt, PDD Wang, YJ Anderson, DZ AF Muller, D Cornell, EA Prevedelli, M Schwindt, PDD Wang, YJ Anderson, DZ TI Magnetic switch for integrated atom optics SO PHYSICAL REVIEW A LA English DT Article ID GUIDING NEUTRAL ATOMS; EVANESCENT-WAVE; COLD ATOMS; WIRE; FIBERS AB A magnetic waveguide structure allows switching of neutral atoms between two guides. The switch consists of lithographically patterned current-carrying wires on a sapphire substrate. By selectively sending current through a particular set of wires, we select the desired output port of an incoming beam. We utilize two different magnetic-guiding schemes to adiabatically manipulate the atom trajectory. C1 Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Quantum Phys Div, Boulder, CO 80309 USA. Univ Florence, Dipartimento Fis, I-50125 Florence, Italy. RP Muller, D (reprint author), Univ Colorado, Dept Phys, Boulder, CO 80309 USA. NR 24 TC 28 Z9 30 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 APR PY 2001 VL 63 IS 4 AR 041602 DI 10.1103/PhysRevA.63.041602 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 422AG UT WOS:000168095300014 ER PT J AU Christianson, RJ Leheny, RL Birgeneau, RJ Erwin, RW AF Christianson, RJ Leheny, RL Birgeneau, RJ Erwin, RW TI Critical dynamics of a spin-5/2 two-dimensional isotropic antiferromagnet SO PHYSICAL REVIEW B LA English DT Article ID 2-DIMENSIONAL HEISENBERG-ANTIFERROMAGNET; SQUARE-LATTICE; LOW-TEMPERATURES; NEUTRON-SCATTERING; CORRELATION LENGTH; RB2MNF4 AB We report a neutron-scattering study of the dynamic spin correlations in Rb2MnF4, a two-dimensional spin-5/2 antiferromagnet. By tuning an external magnetic field to the value for the spin-flop line, we reduce the effective spin anisotropy to essentially zero, thereby obtaining a nearly ideal two-dimensional isotropic anti-ferromagnet. From the shape of the quasielastic peak as a function of temperature, we demonstrate dynamic scaling for this system and find a value for the dynamical exponent z. We compare these results to theoretical predictions for the dynamic behavior of the two-dimensional Heisenberg model, in which deviations from z =1 provide a measure of the corrections to scaling. C1 MIT, Dept Phys, Cambridge, MA 02139 USA. NIST, Div Reactor Radiat, Gaithersburg, MD 20899 USA. RP Christianson, RJ (reprint author), MIT, Dept Phys, Cambridge, MA 02139 USA. NR 21 TC 18 Z9 20 U1 0 U2 5 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 APR 1 PY 2001 VL 63 IS 14 AR 140401 DI 10.1103/PhysRevB.63.140401 PG 4 WC Physics, Condensed Matter SC Physics GA 421HW UT WOS:000168059800002 ER PT J AU Kiryukhin, V Kim, YJ Thomas, KJ Chou, FC Erwin, RW Huang, Q Kastner, MA Birgeneau, RJ AF Kiryukhin, V Kim, YJ Thomas, KJ Chou, FC Erwin, RW Huang, Q Kastner, MA Birgeneau, RJ TI Magnetic properties of the S=1/2 quasi-one-dimensional antiferromagnet CaCu2O3 SO PHYSICAL REVIEW B LA English DT Article ID SYNCHROTRON X-RAY; CU-O SYSTEM; PHASE-TRANSITIONS; HEISENBERG MODEL; SPIN; SCATTERING; LADDERS; CHAIN; SUSCEPTIBILITY; THERMODYNAMICS AB We report single-crystal growth and magnetic susceptibility and neutron diffraction studies of the S = 1/2 quasi-one-dimensional antiferromagnet CaCu2O3. The structure of this material is similar to that of the prototype two-leg spin-ladder compound SrCu2O3. However, the Cu-O-Cu bond angle in the ladder rungs in CaCu2O3 is equal to 123 degrees, and therefore the magnetic interaction along the rung is expected to be much weaker in this material. At high temperatures, the magnetic susceptibility of CaCu2O3 can be decomposed into a contribution from one-dimensional antiferromagnetic chains or finite-size chain segments together with a weak Curie contribution. The intrachain magnetic exchange constant J(parallel to), determined from the magnetic susceptibility measurements, is 2000+/-300 K. CaCu2O3 undergoes a Neel transition at T-N = 25 K with ordering wave vector of [0.429(5), 1/2, 1/2]. The magnetic structure is incommensurate in the direction of the frustrated interchain interaction. Weak commensurate magnetic Bragg peaks with the reduced wave vector (1/2, 1/2, 1/2) are also observed below T-N. Application of a magnetic field induces a metamagnetic transition at which the incommensurability of the magnetic structure is substantially reduced. Above the transition field, the material possesses only short-range magnetic order, and no well defined temperature-driven transition is observed. C1 MIT, Dept Phys, Cambridge, MA 02139 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RP Kiryukhin, V (reprint author), Rutgers State Univ, Dept Phys & Astron, POB 849, Piscataway, NJ 08854 USA. RI Kim, Young-June /G-7196-2011 OI Kim, Young-June /0000-0002-1172-8895 NR 44 TC 43 Z9 43 U1 1 U2 14 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 APR 1 PY 2001 VL 63 IS 14 AR 144418 DI 10.1103/PhysRevB.63.144418 PG 10 WC Physics, Condensed Matter SC Physics GA 421HW UT WOS:000168059800065 ER PT J AU Romero, DB Moritomo, Y Mitchell, JF Drew, HD AF Romero, DB Moritomo, Y Mitchell, JF Drew, HD TI Competition of charge, orbital, and ferromagnetic correlations in layered manganites SO PHYSICAL REVIEW B LA English DT Article ID GIANT MAGNETORESISTANCE; RAMAN-SPECTROSCOPY; ELECTRONIC-STRUCTURE; TRANSPORT-PROPERTIES; MANGANESE OXIDES; LA1.2SR1.8MN2O7; LASR2MN2O7; TRANSITION; SCATTERING; SPECTRA AB The competition of charge, orbital, and ferromagnetic interactions in layered manganites is investigated by magneto-Raman scattering spectroscopy. We find that the colossal magnetoresistance effect in the layered compounds results from the interplay of orbital and ferromagnetic double exchange correlations. inelastic scattering by charge-order fluctuations dominates the quasiparticle dynamics in the ferromagnetic-metal state. It is suppressed at low frequencies, consistent with the opening of a charge-density wave pseudogap. C1 NIST, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Nagoya Univ, CIRSE, Nagoya, Aichi 46401, Japan. Nagoya Univ, Dept Appl Phys, Nagoya, Aichi 46401, Japan. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Romero, DB (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 28 TC 12 Z9 12 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD APR 1 PY 2001 VL 63 IS 13 AR 132404 DI 10.1103/PhysRevB.63.132404 PG 4 WC Physics, Condensed Matter SC Physics GA 418MB UT WOS:000167895000014 ER PT J AU Woo, H Tyson, TA Croft, M Cheong, SW Woicik, JC AF Woo, H Tyson, TA Croft, M Cheong, SW Woicik, JC TI Correlations between the magnetic and structural properties of Ca-doped BiMnO3 SO PHYSICAL REVIEW B LA English DT Article ID ABSORPTION FINE-STRUCTURE; FERROMAGNETIC PEROVSKITE BIMNO3; X-RAY; COLOSSAL MAGNETORESISTANCE; NEGATIVE MAGNETORESISTANCE; ELECTRICAL-PROPERTIES; STRUCTURE SPECTRA; BETA-AGI; K-EDGE; MANGANITES AB The Bi1-xCaxMnO3 system is known to exhibit charge ordering for a much broader range of x than the La1-xCaxMnO3 system. However, the properties of Bi1-xCaxMnO3 over the entire doping range are not well understood. We have performed magnetization and resistivity measurements as well as x-ray absorption and x-ray diffraction measurements on Bi1-xCaxMnO3 to correlate structural, magnetic, and transport properties. The system is insulating and antiferromagnetic for the entire range of x studied (x greater than or equal to0.4) except near x similar to0.9, where we find a canted spin arrangement with approximately one Bohr magneton per Mn site. Detailed magnetization measurements were performed as a function of field and temperature to explore the net moment on the Mn sites as a function of x and reveal the charge ordering and Neel temperatures. X-ray absorption measurements reveal significant structural distortions of the Mn-O bond distributions with increasing Bi content that correlates directly with increasing charge-ordering temperatures. Moreover, the x-ray diffraction data reveal peak splittings consistent with lower-symmetry cells as Bi content increases. These structural-magnetic correlations point to the importance of Mn-O distortions in stabilizing the charge-ordered state in the manganites. C1 New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. Rutgers State Univ, Dept Phys, Piscataway, NJ 08855 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Woo, H (reprint author), New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. NR 57 TC 101 Z9 101 U1 2 U2 23 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 APR 1 PY 2001 VL 63 IS 13 AR 134412 DI 10.1103/PhysRevB.63.134412 PG 12 WC Physics, Condensed Matter SC Physics GA 418MB UT WOS:000167895000062 ER PT J AU Kink, I Laming, JM Takacs, E Porto, JV Gillaspy, JD Silver, E Schnopper, H Bandler, SR Barbera, M Brickhouse, N Murray, S Madden, N Landis, D Beeman, J Haller, EE AF Kink, I Laming, JM Takacs, E Porto, JV Gillaspy, JD Silver, E Schnopper, H Bandler, SR Barbera, M Brickhouse, N Murray, S Madden, N Landis, D Beeman, J Haller, EE TI Analysis of broadband x-ray spectra of highly charged krypton from a microcalorimeter detector of an electron-beam ion trap SO PHYSICAL REVIEW E LA English DT Article ID FE-XVII; NE-LIKE; PLASMAS; ATOMS; KR; COEFFICIENTS; ULTRAVIOLET; DENSITY; REGION; LINES AB Spectra of highly charged Kr ions, produced in an electron-beam ion trap (EBIT), have been recorded in a broad x-ray energy band (0.3 keV to 4 keV) with a microcalorimeter detector. Most of the spectral lines have been identified as transitions of B- to Al-like Kr. The transition energies have been determined with 0.2% uncertainty. A semi-empirical EBIT plasma model has been created to calculate a synthetic spectrum of highly charged Kr and to determine a charge state distribution of Kr ions inside the EBIT. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Res Lab, Washington, DC 20375 USA. MIT, Cambridge, MA 02139 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron GS Vaiana, Palermo, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kink, I (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Bandler, Simon/A-6258-2010; OI Bandler, Simon/0000-0002-5112-8106; Brickhouse, Nancy/0000-0002-8704-4473 NR 48 TC 11 Z9 12 U1 1 U2 2 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 APR PY 2001 VL 63 IS 4 AR 046409 DI 10.1103/PhysRevE.63.046409 PN 2 PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 424CT UT WOS:000168215100065 PM 11308958 ER PT J AU Schulz, JC Warr, GG Butler, PD Hamilton, WA AF Schulz, JC Warr, GG Butler, PD Hamilton, WA TI Adsorbed layer structure of cationic surfactants on quartz SO PHYSICAL REVIEW E LA English DT Article ID SOLID-LIQUID INTERFACES; NEUTRON REFLECTION; HEXADECYLTRIMETHYLAMMONIUM BROMIDE; AQUEOUS-SOLUTION; PHASE-BEHAVIOR; ADSORPTION; MICELLES; SILICA; MICA; MECHANISM AB Recent atomic force microscopy (AFM) surface images of surfactant adsorbed at solid and solution interfaces have shown apparent micellar aggregates familiar from bulk self-assembly. This contradicts the classical picture of laterally unstructured bilayers within which neutron reflectometry (NR) measurements have previously been analyzed. Applying both techniques to surfactant adsorption on quartz, we show that film thickness and coverage parameters derived from NR results are generally consistent with those from AFM and bulk self-assembly. NR by itself allows us to distinguish between actual bilayer and probable aggregate adsorption, which will be of particular importance when a solution's rheology makes AFM imaging impractical. C1 Univ Sydney, Sch Chem, Sydney, NSW 2006, Australia. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Warr, GG (reprint author), Univ Sydney, Sch Chem, Sydney, NSW 2006, Australia. EM g.warr@chem.usyd.edu.au RI Schulz, Jamie/B-3819-2008; Butler, Paul/D-7368-2011 NR 33 TC 7 Z9 7 U1 0 U2 10 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 APR PY 2001 VL 63 IS 4 AR 041604 PN 1 PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 424CQ UT WOS:000168214900049 ER PT J AU Starr, FW Sastry, S La Nave, E Scala, A Stanley, HE Sciortino, F AF Starr, FW Sastry, S La Nave, E Scala, A Stanley, HE Sciortino, F TI Thermodynamic and structural aspects of the potential energy surface of simulated water SO PHYSICAL REVIEW E LA English DT Article ID KINETIC GLASS-TRANSITION; NORMAL-MODE ANALYSIS; SUPERCOOLED WATER; LIQUID WATER; CONFIGURATIONAL ENTROPY; MOLECULAR MOBILITY; INHERENT STRUCTURE; FORMING LIQUID; SLOW DYNAMICS; LANDSCAPE AB Relations between the thermodynamics and dynamics of supercooled liquids approaching a glass transition is a topic of considerable interest. The potential energy surface of model liquids has been increasingly studied, since it provides a connection between the configurational component of the partition function on the one hand, and the system dynamics on the other. This connection is most obvious at low temperatures, where the motion of the system can be partitioned into vibrations within a basin of attraction and infrequent interbasin transitions. in this work, we present a description of the potential energy surface properties of supercooled liquid water. The dynamics of this model have been studied in great detail in recent years. We locate the minima sampled by the liquid by "quenches" from equilibrium configurations generated via molecular dynamics simulations, and then calculate the temperature and density dependence of the basin energy, degeneracy, and shape. The temperature dependence of the energy of the minima is qualitatively similar to simple liquids, but has anomalous density dependence. The unusual density dependence is also reflected in the configurational entropy, the thermodynamic measure of degeneracy. Finally, we study the structure of simulated water at the minima, which provides insight on the progressive tetrahedral ordering of the liquid on cooling. C1 Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. Boston Univ, Ctr Computat Sci, Boston, MA 02215 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. Jawaharlal Nehru Ctr Adv Sci Res, Bangalore 560064, Karnataka, India. Univ Rome La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Univ Rome La Sapienza, Ist Nazl Fis Mat, I-00185 Rome, Italy. RP Starr, FW (reprint author), Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. RI Sciortino, Francesco/B-4768-2012; Starr, Francis/C-7703-2012; Scala, Antonio/A-2098-2012 OI Scala, Antonio/0000-0002-3414-2686 NR 68 TC 64 Z9 64 U1 1 U2 8 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 APR PY 2001 VL 63 IS 4 AR 041201 DI 10.1103/PhysRevE.63.041201 PN 1 PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 424CQ UT WOS:000168214900019 PM 11308829 ER PT J AU Nakatani, AI Chen, W Schmidt, RG Gordon, GV Han, CC AF Nakatani, AI Chen, W Schmidt, RG Gordon, GV Han, CC TI Chain dimensions in polysilicate-filled poly(dimethyl siloxane) SO POLYMER LA English DT Article DE small angle neutron scattering; poly(dimethyl siloxane); polysilicate fillers ID ANGLE NEUTRON-SCATTERING; X-RAY-SCATTERING; CARBON-BLACK COMPOSITES; POLYMER-SOLUTIONS; FRACTAL STRUCTURE; LIGHT-SCATTERING; SIMULATIONS; REINFORCEMENT; POLYSTYRENE; MORPHOLOGY AB We present experimental results on the single chain dimensions of isotopic blends (both mismatched and matched molecular masses) of poly(dimethyl siloxane) (PDMS) containing trimethylsilyl-treated polysilicate particles (fillers) and compare these results with Monte Carlo calculations. For polymer chains which are approximately the same size as the filler particle, a decrease in chain dimensions is observed relative to the unfilled chain dimensions at all filler concentrations. For larger chains, at low filler concentrations, an increase in chain dimensions relative to the unfilled chain dimensions is observed. Both results are in agreement with existing Monte Carlo predictions. However, at even higher filler contents, which are beyond the scope of the Monte Carlo predictions, the chain dimensions reach a maximum value before decreasing to values which are still larger than the unfilled chain dimensions. A simple excluded volume model is proposed which accounts for these observations at higher filler content. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. Dow Corning Corp, Midland, MI 48686 USA. RP Nakatani, AI (reprint author), NIST, Div Polymers, 100 Bur Dr,Stop 8542,Bldg 224, Gaithersburg, MD 20899 USA. NR 36 TC 100 Z9 101 U1 4 U2 29 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD APR PY 2001 VL 42 IS 8 BP 3713 EP 3722 DI 10.1016/S0032-3861(00)00771-0 PG 10 WC Polymer Science SC Polymer Science GA 396CX UT WOS:000166619700044 ER PT J AU Chin, JW Aouadi, K Haight, MR Hughes, WL Nguyen, T AF Chin, JW Aouadi, K Haight, MR Hughes, WL Nguyen, T TI Effects of water, salt solution and simulated concrete pore solution on the properties of composite matrix resins used in civil engineering applications SO POLYMER COMPOSITES LA English DT Article ID DEGRADATION; POLYESTER AB nOne of the obstacles hindering the acceptance of polymer composites in civil engineering applications is the susceptibility of the polymeric matrix to degradation that is initiated by moisture, temperature, and corrosive chemical environments. The objective of this study was to characterize chemical and physical changes in polymer matric; resins following exposure to these environments. Resin systems studied were vinyl ester and isophthalic polyester, both of which are proposed for use in construction applications. Unreinforced free films were exposed to water, alkaline and saline environments at ambient and elevated temperatures for extended periods of time. Changes in strength and thermophysical properties were evaluated through tensile testing, dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). Chemical degradation of the polymers was characterized using Fourier transform infrared (FTIR) spectroscopy. Energy dispersive X-ray (EDX) analysis of specimens following exposure was carried out to determine if ion diffusion into the bulk polymer occurred. Only minor changes in the glass transition temperatures of the polymers were observed after prolonged exposure at elevated temperature, but more substantial changes were noted in tensile strength, particularly in the case of the isophthalic polyester. Examination of the polymers following immersion in salt solution and alkaline solution showed essentially no ionic penetration into the bulk, with the exception of specimens that were visibly degraded. Spectroscopic analysis of chemical structure prior to and following exposure revealed varying degrees of ester hydrolysis. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Chin, JW (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8621, Gaithersburg, MD 20899 USA. NR 19 TC 36 Z9 38 U1 0 U2 5 PU SOC PLASTICS ENG INC PI BROOKFIELD PA 14 FAIRFIELD DR, BROOKFIELD, CT 06804-0403 USA SN 0272-8397 J9 POLYM COMPOSITE JI Polym. Compos. PD APR PY 2001 VL 22 IS 2 BP 282 EP 297 DI 10.1002/pc.10538 PG 16 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA 422YK UT WOS:000168146700010 ER PT J AU Hinz, HJ Schwarz, FP AF Hinz, HJ Schwarz, FP TI Measurement and analysis of results obtained on biological substances with differential scanning calorimetry SO PURE AND APPLIED CHEMISTRY LA English DT Article ID HEAT-CAPACITY DATA; DODECAMERIC GLUTAMINE-SYNTHETASE; ACANTHAMOEBA MYOSIN-II; THERMODYNAMIC DATA; ESCHERICHIA-COLI; THERMAL-DENATURATION; UNFOLDING TRANSITION; PROTEIN STABILITY; SUBTILISIN BPN'; CALIBRATION AB Differential scanning calorimeters (DSCs) have been widely used to determine the thermodynamics of phase transitions and conformational changes in biological systems including proteins, nucleic acid sequences, and lipid assemblies. DSCs monitor the temperature difference between two vessels, one containing the biological solution and the other containing a reference solution, as a function of temperature at a given scan rate. Recommendations for DSC measurement procedures, calibration procedures, and procedures for testing the performance of the DSC are described. Analysis of the measurements should include a correction for the time response of the instrument and conversion of the power vs. time curve to a heat capacity vs, temperature plot. Thermodynamic transition models should only be applied to the analysis of the heat capacity curves if the model-derived transition temperatures and enthalpies are independent of the DSC scan rate. Otherwise, kinetic models should be applied to the analysis of the data. Application of thermodynamic transition models involving two states, two states and dissociation, and three states to the heat capacity vs. temperature data are described. To check the operating performance with standard DSCs, samples of 1 to 10 mg mL(-1) solutions of hen egg white lysozyme in 0.1 M HCl-glycine buffer at pH = 2.4 +/- 0. 1 were sent to six different DSC laboratories worldwide. The values obtained from proper measurements and application of a two-state transition model yielded an average unfolding transition temperature for lysozyme of 331.2 K with values ranging from 329.4 to 331.9 K. and an average transition enthalpy of 405 kJ mol(-1) with values ranging from 377 to 439 kJ mol(-1). It is recommended that the reporting of DSC results be specific with regard to the composition of the solution. the operating conditions and calibrations of the DSC, determination of base lines that may be model-dependent. and the model used in the analysis of the data. C1 Univ Munster, Inst Phys Chem, D-48149 Munster, Germany. Natl Inst Stand & Technol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. RP Hinz, HJ (reprint author), Univ Munster, Inst Phys Chem, Schlosspl 4-7, D-48149 Munster, Germany. NR 55 TC 34 Z9 36 U1 2 U2 12 PU INT UNION PURE APPLIED CHEMISTRY PI RES TRIANGLE PK PA 104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USA SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD APR PY 2001 VL 73 IS 4 BP 745 EP 759 DI 10.1351/pac200173040745 PG 15 WC Chemistry, Multidisciplinary SC Chemistry GA 447WR UT WOS:000169595900005 ER PT J AU Schutt, H Spetzler, H AF Schutt, H Spetzler, H TI Capillary crack imbibition: A theoretical and experimental study using a Hele-Shaw cell SO PURE AND APPLIED GEOPHYSICS LA English DT Article DE capillary pressure; crack; fluid flow; groundwater contamination; Hele-Shaw cell ID PARTIAL GAS SATURATION; SEISMIC ATTENUATION; ROCKS; DISPERSION AB We study the filling of horizontal cracks with constant aperture driven by capillary forces. The physical model of the crack consists of a narrow gap between two flat glass plates (Hele-Shaw cell). The liquid enters the gap through a hole in the bottom plate. The flow is driven purely by the force acting on the contact lines between solid, liquid, and gas. We developed a theoretical model for this type of flow on the basis of Darcy's law; it allows for the consideration of different surface conditions. We run the experiment for two surface conditions: Surfaces boiled in hydrogen peroxide to remove initial contamination, and surfaces contaminated with 2-propanol after boiling in hydrogen peroxide. The flow rate depends on the gap aperture and on the interaction of the liquid with the air and the solid surfaces: The smaller the aperture, the lower the flow rate due to viscous resistance of the liquid. The flow rate is also reduced when the glass surfaces are contaminated with 2-propanol. The contact line force per unit length is approximately 60% higher on clean glass surfaces than it is on glass surfaces with the 2-propanol contamination. These experimental results are in agreement with our theoretical model and are confirmed by independent measurements of the liquid-solid interaction in capillary rise experiments under static conditions with the same Hele-Shaw cell. Another aspect of this study is the distribution of the liquid for the different surface conditions. The overall shape is a circular disk, as assumed in the theoretical model. However, a pronounced contact line roughness develops in case of the surfaces contaminated with 2-propanol, and air bubbles are trapped behind the contact line. A further analysis of the flow regime using the capillary number and the ratio of the viscosities of the involved fluids (water and air) reveals that the experiments take place in the transition zone between stable displacement and capillary fingering, i.e., neither viscous nor capillary fingers develop under the conditions of the experiment. The contact line roughness and the trapped air bubbles in the contaminated cell reflect local inhomogeneities of the surface wettability. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. RP Schutt, H (reprint author), Heriot Watt Univ, Dept Petr Engn, Edinburgh EH14 4AS, Midlothian, Scotland. NR 22 TC 1 Z9 1 U1 1 U2 6 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD APR PY 2001 VL 158 IS 4 BP 627 EP 646 DI 10.1007/PL00001197 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 439WB UT WOS:000169139600001 ER PT J AU Xu, Q Gu, H Yang, S AF Xu, Q Gu, H Yang, S TI Simple adjoint method for three-dimensional wind retrievals from single-Doppler radar SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE dual-Doppler reflectivity; Phoenix ID PHOENIX-II; VARIATIONAL ANALYSIS; 3-DIMENSIONAL WIND; BOUNDARY-LAYER; FIELDS; ASSIMILATION; REFLECTIVITY; MODEL; AIR AB A new simple adjoint (SA) method is developed for retrieving three-dimensional wind from single-Doppler observations. The method uses the full momentum equations and the mass continuity equation as weak constraints, in addition to the strong constraints of the radial-wind and reflectivity equations. With these weak constraints, the unknown source term in the previous two-dimensional SA method is now explicitly estimated in terms of perturbation pressure and buoyancy. This improves the wind retrievals, although the retrieved perturbation pressure and buoyancy may not de accurate. Bi-spline basis functions are used to express the retrieved fields on coarse finite-element meshes. The bi-spline representation filters short-wave noise and effectively reduces the number of unknowns that need to be retrieved, so the retrievals are further improved. The methods tested with Doppler-radar data collected during the Phoenix II field experiment. The retrieved winds are very close to the dual-Doppler observed winds and the difference is about 1.0 m s(-1). The retrievals can be further improved by adding smoothness constraints in the cost function, especially when the bi-spline representation is not used. The robustness of the method is examined in terms of sensitivities to the weights specified for the weak constraints in the cost function. C1 Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Norman, OK 73019 USA. RP Xu, Q (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 24 TC 22 Z9 26 U1 0 U2 1 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD APR PY 2001 VL 127 IS 573 BP 1053 EP 1067 DI 10.1256/smsqj.57318 PN A PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 429DD UT WOS:000168500000018 ER PT J AU Muller, R Schmidt, U Engel, A McKenna, DS Proffitt, MH AF Muller, R Schmidt, U Engel, A McKenna, DS Proffitt, MH TI The O-3-N2O relation from balloon-borne observations as a measure of Arctic ozone loss in 1991/92 SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE Arctic; chemical ozone destruction; mixing across vortex edge; ozone loss; stratosphere; tracer relations ID IN-SITU MEASUREMENTS; HALOGEN OCCULTATION EXPERIMENT; ATMOSPHERE RESEARCH SATELLITE; POLAR VORTEX AIR; STRATOSPHERIC EXPEDITION; NORTHERN-HEMISPHERE; WINTER STRATOSPHERE; PROFILE OBSERVATIONS; VERTICAL STRUCTURE; MODEL SIMULATIONS AB We analyse balloon-borne measurements of ozone (O-3) and nitrous oxide (N2O) in the Arctic, obtained during the European Arctic Stratospheric Ozone Experiment campaign in winter and early spring 1991/92. Using N2O as a long-lived tracer, we identify chemical ozone depletion in the Arctic vortex in the presence of ozone variations caused by dynamical effects. Substantial chemical ozone loss of about 25% locally over the height range of 15-21 km, corresponding to the potential-temperature range of 400-550 K, is deduced for late winter. Mixing processes can be ruled out as the major cause of the observed anomaly in the O-3-N2O relation by considering the concurrently measured chloroflurocarbon-11-N2O relation. The chemical ozone loss derived from the balloon-borne measurements is in agreement with the loss derived, following the same methodology, from satellite (Halogen Occultation Experiment) vortex observations. Consistent with the dynamical development of the polar vortex and with the observed chlorine activation, the major fraction of the ozone decline occurred before February 1992. The reduced ozone levels persisted over the lifetime of the polar vortex until late March 1992. C1 Forschungszentrum Julich, Inst Stratospher Chem ICG 1, D-52425 Julich, Germany. Goethe Univ Frankfurt, D-6000 Frankfurt, Germany. NOAA, Aeron Lab, Silver Spring, MD USA. RP Forschungszentrum Julich, Inst Stratospher Chem ICG 1, Postfach 1913, D-52425 Julich, Germany. EM ro.mueller@fz-juelich.de RI Muller, Rolf/A-6669-2013; McKenna, Daniel/E-7806-2014; Engel, Andreas/E-3100-2014 OI Muller, Rolf/0000-0002-5024-9977; McKenna, Daniel/0000-0002-4360-4782; Engel, Andreas/0000-0003-0557-3935 NR 79 TC 35 Z9 35 U1 0 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0035-9009 EI 1477-870X J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD APR PY 2001 VL 127 IS 574 BP 1389 EP 1412 DI 10.1256/smsqj.57414 PN B PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 444AN UT WOS:000169375900014 ER PT J AU Fields, E AF Fields, E TI NOAA's recruitment and retention woes SO SEA TECHNOLOGY LA English DT Editorial Material C1 NOAA Corps, Washington, DC 20230 USA. RP Fields, E (reprint author), NOAA Corps, Washington, DC 20230 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 USA SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD APR PY 2001 VL 42 IS 4 BP 101 EP 101 PG 1 WC Engineering, Ocean SC Engineering GA 425WH UT WOS:000168314300011 ER PT J AU Choquette, SJ Travis, JC O'Neal, LE Zhu, CJ Duewer, DL AF Choquette, SJ Travis, JC O'Neal, LE Zhu, CJ Duewer, DL TI A rare-Earth-oxide glass for the wavelength calibration of near-infrared dispersive and fourier-transform spectrometers SO SPECTROSCOPY LA English DT Article ID STANDARD AB This article describes SRM 2035, a new optical wavelength standard available from the National Institute of Standards and Technology. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Choquette, SJ (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Analyt Chem, Bldg 227,MS 20899-8394, Gaithersburg, MD 20899 USA. RI Duewer, David/B-7410-2008 NR 17 TC 3 Z9 3 U1 0 U2 2 PU ADVANSTAR COMMUNICATIONS PI DULUTH PA 131 W FIRST ST, DULUTH, MN 55802 USA SN 0887-6703 J9 SPECTROSCOPY JI Spectroscopy PD APR PY 2001 VL 16 IS 4 BP 14 EP 19 PG 8 WC Spectroscopy SC Spectroscopy GA 422XY UT WOS:000168145600001 ER PT J AU Pfeifer, L AF Pfeifer, L TI The Shuckburgh scale SO SURVEY REVIEW LA English DT Article AB Airy stated unequivocally that the dimensions of is Figure of the Earth, better known as the Airy 1830 ellipsoid, were given in "feet of the Shuckburgh standard", further interpreted as feet of th first yard of the Shuckburgh scale. Because relation to the international metre was ill-defined, approximate metric equivalents have been used, e.g. by the goedetic datum of Great Britian. This article presents a definitive determination of thermal expansion of the Shuckburgh scale and of the length of its first yard. C1 NOAA, Washington, DC USA. RP Pfeifer, L (reprint author), 829 Virginia Court, Cheyenne, WY 82009 USA. NR 20 TC 1 Z9 1 U1 0 U2 0 PU COMMONWEALTH ASSOC SURVEYING LAND ECONOMY, C A S L E PI BRISTOL PA UNIV WEST ENGLAND, C/O FACULTY BUILT ENVIRONMENT, FRENCHAY CAMPUS, COLDHARBOUR L, BRISTOL BS16 1QY, ENGLAND SN 0039-6265 J9 SURV REV JI Surv. Rev. PD APR PY 2001 VL 36 IS 280 BP 101 EP 109 PG 9 WC Engineering, Civil; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA 412EA UT WOS:000167540400002 ER PT J AU McCowan, CN Siewert, TA Vigliotti, DP Wang, CM AF McCowan, CN Siewert, TA Vigliotti, DP Wang, CM TI Reference materials for weld metal ferrite content: Gauge calibration and material characterization SO WELDING JOURNAL LA English DT Article DE ferrite; ferrite content; ferrite detector; ferrite number; magne-gauge; reference material; stainless steel AB The Ferrite Number (FN) is a measure of the ferrite content in stainless steel welds. Accurate measurement of the FN is important because the relative amounts of ferritic and austenitic phases influence the physical and mechanical properties (as well as general corrosion and stress corrosion cracking resistance) of stainless steel welds. This report documents the procedures used to evaluate several batches of certrifugally cast reference materials and to assign reference values that can be used to calibrate several types of instruments. it also describes some general characteristics of the specimens. Our initial effort was devoted to finding and reducing sources of uncertainty in the gauges (instruments for measuring ferrite content in units of FN) and in the calibration procedures. After improving our gauges and procedures, we found our calibration lines were nearly linear over the range of 0 to 100 FN and the gauges compared well to gauges used by The Welding institute (TWI), which had assigned the certified FN values to secondary specimens produced in the past. The measurements on the reference materials showed the standard deviations in FN for the secondary specimens were typically less than 0.5 FN for the 0 to 30 FN range, and less than 3 FN for the 30 to 100 FN range. The microstructure was found to be a finely dispersed and homogeneous mixture of ferritic and austenitic phases, with a percent ferrite area fraction that was nearly equivalent to the FN (up to about 60 FN) assigned to the reference materials. C1 NIST, Mat Sci & Engn Lab, Mat Reliabil Div, Boulder, CO USA. NIST, Informat Technol Lab, Stat Engn Div, Boulder, CO USA. RP McCowan, CN (reprint author), NIST, Mat Sci & Engn Lab, Mat Reliabil Div, Boulder, CO USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU AMER WELDING SOC PI MIAMI PA 550 N W LEJEUNE RD, MIAMI, FL 33126 USA SN 0043-2296 J9 WELD J JI Weld. J. PD APR PY 2001 VL 80 IS 4 BP 106S EP 114S PG 9 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 746KT UT WOS:000186746100019 ER PT J AU Whiteman, DN Evans, KD Demoz, B Starr, DO Eloranta, EW Tobin, D Feltz, W Jedlovec, GJ Gutman, SI Schwemmer, GK Cadirola, M Melfi, SH Schmidlin, FJ AF Whiteman, DN Evans, KD Demoz, B Starr, DO Eloranta, EW Tobin, D Feltz, W Jedlovec, GJ Gutman, SI Schwemmer, GK Cadirola, M Melfi, SH Schmidlin, FJ TI Raman lidar measurements of water vapor and cirrus clouds during the passage of Hurricane Bonnie SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT 2nd AGU Chapman Conference on Water Vapor in the Climate System CY OCT 12-15, 1999 CL POTOMAC, MARYLAND SP Amer Geophysic Union ID EXTINCTION; SCATTERING; METHODOLOGY; TEMPERATURE; ABSORPTION; ATMOSPHERE; RETRIEVAL; PROFILES; HUMIDITY; AEROSOLS AB The NASA GSFC Scanning Raman Lidar (SRL) was stationed on Andros Island in the Bahamas during August-September 1998 as a part of the third Convection and Moisture Experiment (CAMEX 3) which focused on hurricane development and tracking. During the period August 21-24, Hurricane Bonnie passed near Andros Island and influenced the water vapor and cirrus cloud measurements acquired by the SRL. Two drying signatures related to the hurricane were recorded by the SRL and other sensors. Cirrus cloud optical depths (at 351 nm) were also measured during this period. Optical depth values ranged from less than 0.01 to 1.5, The influence of multiple scattering on these optical depth measurements was studied. A correction technique is presented which minimizes the influences of multiple scattering and derives information about cirrus cloud optical and physical properties. The UV/IR cirrus cloud optical depth ratio was estimated on the basis of a comparison of lidar and GOES 8 measurements. Simple radiative transfer model calculations compared with GOES satellite brightness temperatures indicate that satellite radiances are significantly affected by the presence of cirrus clouds if IR optical depths are similar to0.005 or greater. Using the International Satellite Cloud Climatology Project (ISCCP) detection threshold for cirrus clouds on the GOES data presented here, a high bias of up to 40% was found in the GOES precipitable water retrieval. C1 NASA, Goddard Space Flight Ctr, Earth Sci Directorate, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Catonsville, MD 21228 USA. Univ Wisconsin, Ctr Space Sci & Engn, Madison, WI 53706 USA. NASA, George C Marshall Space Flight Ctr, Global Hydrol & Climate Ctr, Huntsville, AL 35812 USA. NOAA, Forecast Syst Lab, Golden, CO 80401 USA. RP Whiteman, DN (reprint author), NASA, Goddard Space Flight Ctr, Earth Sci Directorate, Greenbelt, MD 20771 USA. RI Demoz, Belay/N-4130-2014 NR 51 TC 49 Z9 49 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 27 PY 2001 VL 106 IS D6 BP 5211 EP 5225 DI 10.1029/2000JD900621 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 413XB UT WOS:000167635900009 ER PT J AU Escoffier, C Bates, JJ Chedin, A Rossow, WB Schmetz, J AF Escoffier, C Bates, JJ Chedin, A Rossow, WB Schmetz, J TI Comparison of upper tropospheric humidity retrievals from TOVS and Meteosat SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT 2nd AGU Chapman Conference on Water Vapor in the Climate System CY OCT 12-15, 1999 CL POTOMAC, MARYLAND SP Amer Geophysic Union ID WATER-VAPOR CHANNEL; RELATIVE-HUMIDITY; SATELLITE; CALIBRATION; CLIMATOLOGY; BUDGET; FIELD AB Two different methods for retrieving upper tropospheric humidity (UTH) from the TIROS Operational Vertical Sounder (TOVS) instruments aboard NOAA polar orbiting satellites are presented and compared. The first one, from the Environmental Technology Laboratory, computed by J. J. Bates and D. L. Jackson, estimates UTH from a simplified radiative transfer analysis of the upper tropospheric infrared water vapor channel at 6.7 mum wavelength measured by High-resolution Infrared Radiation Sounder (HIRS). The second one results from a neural network analysis of the TOVS (HIRS and Microwave Sounding Unit (MSU)) data developed at the Laboratoire de Meteorologie Dynamique. Although the two methods give very similar retrievals in temperate regions (30 degrees -60 degreesN and S), the latter is larger by up to 16% in the tropics. The two data sets have also been compared with the UTH retrievals from infrared radiance measurements at 6.3 mum wavelength from the geostationary satellite Meteosat. These products are taken from the archive without any reprocessing that would take care of known biases. Since the Meteosat UTH in 1989 was confined to clear-sky areas, it has a dry bias. The differences observed among the three data sets can be explained. UTH computation is sensitive to assumed air temperature and humidity profiles. Despite the biases the spatial and temporal correlations are very good. Overall, the comparison of the two TOVS retrievals provides an assessment of the UTH uncertainties, about 15-25% (relative). With regard to the Meteosat UTH it is concluded that the archived product performs well in depicting spatial and temporal changes. For future quantitative analyses, a reprocessing of the Meteosat UTH is suggested. C1 Columbia Univ, Goddard Inst Space Studies, New York, NY 10025 USA. NOAA, ERL, Environm Technol Lab, Boulder, CO 80303 USA. Ecole Polytech, Meteorol Dynam Lab, F-91128 Palaiseau, France. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. European Org Exploitat Meteorol Satellites, D-64295 Darmstadt, Germany. RP Escoffier, C (reprint author), Columbia Univ, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. RI Bates, John/D-1012-2009; Rossow, William/F-3138-2015 OI Bates, John/0000-0002-8124-0406; NR 32 TC 9 Z9 9 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 27 PY 2001 VL 106 IS D6 BP 5227 EP 5238 DI 10.1029/2000JD900553 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 413XB UT WOS:000167635900010 ER PT J AU Gillette, DA Chen, WA AF Gillette, DA Chen, WA TI Particle production and aeolian transport from a "supply-limited" source area in the Chihuahuan desert, New Mexico, United States SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT 2nd AGU Chapman Conference on Water Vapor in the Climate System CY OCT 12-15, 1999 CL POTOMAC, MARYLAND SP Amer Geophysic Union ID THRESHOLD FRICTION VELOCITY; WIND EROSION; SALTATION; DUST AB Wind erosion mechanisms were investigated for the "scrape site" at the Jornada Experimental Range near Las Cruces, New Mexico, in the Chihuahuan desert. The scrape site was denuded of vegetation and scraped flat in 1991. We adopted the site in 1994 because it offered an opportunity to study wind erosion mechanisms for a large area of unprotected sandy and crusted soil in an otherwise natural setting and over a period of several years. We installed and operated the following instrumentation for a period of 35 months: three meteorological towers, each 2 m in height, with wind speed sensors at 0.2, 0.5, 1.0, and 2.0 m above ground; air temperature at 0.2 and 2 m height; rain gauge; seven sets of particle collectors at 0.1, 0.5, and 1.0 m heights; and three fast-response particle mass flux sensors at 0.02, 0.1, 0.2, and 0.5 m heights; all along a transect crossing the site and parallel to the predominant southwesterly wind direction. The minimum threshold friction velocity for the scrape site with a thin layer of loose material was 25 cm s(-1). This minimum threshold velocity increased to as high as 100 cm s(-1) depending on the degree of particle depletion and the site's status which varied between supply unlimited just after a high wind episode and supply limited which was more typical for the rest of the time. The dominant mechanism producing fresh sediment for transport was sandblasting of the surface crust. The measurements showed that supply and availability of loose, fine particles on the surface is a strong control of rates of erosion rather than wind energy alone. C1 NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27711 USA. RP Gillette, DA (reprint author), NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27711 USA. NR 24 TC 57 Z9 60 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 27 PY 2001 VL 106 IS D6 BP 5267 EP 5278 DI 10.1029/2000JD900674 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 413XB UT WOS:000167635900013 ER PT J AU Cooper, OR Moody, JL Parrish, DD Trainer, M Ryerson, TB Holloway, JS Hubler, G Fehsenfeld, FC Oltmans, SJ Evans, MJ AF Cooper, OR Moody, JL Parrish, DD Trainer, M Ryerson, TB Holloway, JS Hubler, G Fehsenfeld, FC Oltmans, SJ Evans, MJ TI Trace gas signatures of the airstreams within North Atlantic cyclones: Case studies from the North Atlantic Regional Experiment (NARE '97) aircraft intensive SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT 2nd AGU Chapman Conference on Water Vapor in the Climate System CY OCT 12-15, 1999 CL POTOMAC, MARYLAND SP Amer Geophysic Union ID CARBON-MONOXIDE; STRATOSPHERIC INTRUSIONS; TROPOSPHERIC OZONE; BOUNDARY-LAYER; TRANSPORT; NITROGEN; EXCHANGE; DISTRIBUTIONS; FLUORESCENCE; CLIMATOLOGY AB This study reveals how airstreams within midlatitude cyclones draw and export trace gases from the polluted continental boundary layer, the midtroposphere, and the stratosphere of North America to the troposphere of the North Atlantic Ocean. The North Atlantic Regional Experiment (NARE) produced aircraft-based trace gas measurements from eight midlatitude cyclones during the autumn of 1997, Meteorological and back trajectory analysis identified the various component airstreams of several cyclones, including a cold conveyor belt, two warm conveyor belts, a dry airstream, a previously undefined post cold front airstream, and a streamer fragment that originated in a dry airstream off the coast of California. O-3, CO, and NOgamma mixing ratio distributions and relationships were determined for each airstream. Airstream chemical composition was related to the origin and transport history of the associated air mass. The lowest O-3 values were associated with airstreams originating in Canada or the Atlantic Ocean marine boundary layer; the highest O-3 values were associated with airstreams with a recent stratospheric component. The highest CO values were associated with lower tropospheric outflow from New England and a warm conveyor belt that advected boundary layer CO from the southeast United States to the mid and upper troposphere. The highest NOgamma values were also the result of lower troposphere polluted outflow from New England. Most NOgamma was removed from the airstreams that transported polluted boundary layer air to the free troposphere, A steep and positive O-3/NOgamma slope was found for all airstreams in the free troposphere regardless of air mass origin. C1 Univ Virginia, Dept Environm Sci, Charlottesville, VA 22904 USA. NOAA, Aeron Lab, Boulder, CO 80305 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Univ Cambridge, Ctr Atmospher Sci, Cambridge, England. RP Cooper, OR (reprint author), Univ Virginia, Dept Environm Sci, POB 400123, Charlottesville, VA 22904 USA. RI Hubler, Gerhard/E-9780-2010; Parrish, David/E-8957-2010; Evans, Mathew/A-3886-2012; Holloway, John/F-9911-2012; Cooper, Owen/H-4875-2013; Trainer, Michael/H-5168-2013; Ryerson, Tom/C-9611-2009; Fehsenfeld, Frederick/I-4876-2013 OI Parrish, David/0000-0001-6312-2724; Evans, Mathew/0000-0003-4775-032X; Holloway, John/0000-0002-4585-9594; NR 62 TC 94 Z9 94 U1 1 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 27 PY 2001 VL 106 IS D6 BP 5437 EP 5456 DI 10.1029/2000JD900574 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 413XB UT WOS:000167635900023 ER PT J AU Grohn, F Kim, G Bauer, AJ Amis, EJ AF Grohn, F Kim, G Bauer, AJ Amis, EJ TI Nanoparticle formation within dendrimer-containing polymer networks: Route to new organic-inorganic hybrid materials SO MACROMOLECULES LA English DT Article ID SMALL-ANGLE SCATTERING; STARBURST DENDRIMERS; POLY(AMIDOAMINE) DENDRIMERS; EPR TECHNIQUE; GOLD; NANOCLUSTERS; NANOCOMPOSITES; COLLOIDS; TRANSFORMATION; TEMPLATES AB Higher generation poly(amidoamine) (PAMAM) dendrimers have the unique ability td act as templates for the formation of inorganic nanoclusters. Here, we use dendrimers dispersed in a polymer matrix to create a new type of polymer-inorganic composite material. Hydrophilic polymer networks (poly(2-hydroxyethyl methacrylate)) that contain poly(amidoamine) dendrimers were swollen in aqueous solution, and metal ions were attached to the dendrimers. Chemical reduction on these precursor ions results in nanoparticles that are located inside the dendrimers, which are dispersed in the polymer matrix. Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) were used to characterize gold, platinum, and copper nanoclusters within the polymer networks. These new organic-inorganic hybrid materials may be important for a combination of optical or catalytic properties of the colloids with the mechanical properties provided by the polymer network. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Amis, EJ (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 27 TC 107 Z9 109 U1 3 U2 29 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAR 27 PY 2001 VL 34 IS 7 BP 2179 EP 2185 DI 10.1021/ma001489j PG 7 WC Polymer Science SC Polymer Science GA 413MH UT WOS:000167615600021 ER PT J AU Lenhart, JL van Zanten, JH Dunkers, JP Parnas, RS AF Lenhart, JL van Zanten, JH Dunkers, JP Parnas, RS TI Studying the buried interfacial region with an immobilized fluorescence probe SO MACROMOLECULES LA English DT Article ID ULTRATHIN POLYMER-FILMS; GLASS-TRANSITION TEMPERATURE; EXCIMER FLUORESCENCE; WATER-ADSORPTION; MOLECULAR PROBE; THIN-FILMS; MOBILITY; SPECTROSCOPY; CURE; REFLECTION AB The properties of a buried epoxy/glass interfacial region were studied by covalently grafting a fluorescent probe to the glass surface. A (dimethylamino)nitrostilbene (DMANS) fluorophore was tethered to a triethoxysilane coupling agent, generating a fluorescently labeled silane coupling agent (FLSCA). The glass surface was coated with a silane layer that was doped with small amounts of FLSCA. The emission maximum from grafted FLSCA was different than when the dye was dissolved in bulk resin, suggesting a different interfacial structure. When the dye was dissolved in bulk cured resin, a red shift in the emission maximum was detected as the resin temperature was increased. A distinct break in the fluorescence maximum vs temperature slope was detected at the glass transition of the bulk resin. The slope became larger at temperatures above T-g. A similar break was observed from grafted FLSCA, suggesting that the grafted dye was sensitive to an apparent glass transition in the buried interfacial region. The temperature of the apparent interfacial transition measured by grafted FLSCA could be lower or higher than the bulk polymer T-g, depending on the initial structure of the grafted silane layer. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. N Carolina State Univ, Dept Chem Engn, Raleigh, NC 27695 USA. Univ Connecticut, Inst Sci Mat, Storrs, CT 06269 USA. Univ Connecticut, Dept Chem Engn, Storrs, CT 06269 USA. RP Parnas, RS (reprint author), Katholieke Univ Leuven, MTM Dept, Croylaan 2, B-3001 Heverlee, Belgium. NR 33 TC 21 Z9 21 U1 3 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAR 27 PY 2001 VL 34 IS 7 BP 2225 EP 2231 DI 10.1021/ma0015572 PG 7 WC Polymer Science SC Polymer Science GA 413MH UT WOS:000167615600027 ER PT J AU Gonzalez, C AF Gonzalez, C TI Quantum chemistry SO CHEMICAL & ENGINEERING NEWS LA English DT Article C1 Natl Inst Stand & Technol, Computat Chem Grp, Gaithersburg, MD 20899 USA. RP Gonzalez, C (reprint author), Natl Inst Stand & Technol, Computat Chem Grp, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD MAR 26 PY 2001 VL 79 IS 13 BP 90 EP 90 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 415JD UT WOS:000167717100061 ER PT J AU Stranick, SJ AF Stranick, SJ TI Chemical microscopy SO CHEMICAL & ENGINEERING NEWS LA English DT Article C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Stranick, SJ (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD MAR 26 PY 2001 VL 79 IS 13 BP 122 EP 122 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 415JD UT WOS:000167717100077 ER PT J AU Tarlov, MJ AF Tarlov, MJ TI Cultivating a flow of "cool ideas" SO CHEMICAL & ENGINEERING NEWS LA English DT Article C1 Natl Inst Stand & Technol, Proc Sensing Grp, Proc Measurements Div, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Tarlov, MJ (reprint author), Natl Inst Stand & Technol, Proc Sensing Grp, Proc Measurements Div, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD MAR 26 PY 2001 VL 79 IS 13 BP 204 EP 204 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 415JD UT WOS:000167717100126 ER PT J AU Vasquez, GB AF Vasquez, GB TI Biotechnology: A look ahead SO CHEMICAL & ENGINEERING NEWS LA English DT Article C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Vasquez, GB (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD MAR 26 PY 2001 VL 79 IS 13 BP 210 EP 210 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 415JD UT WOS:000167717100131 ER PT J AU Nelson, BC AF Nelson, BC TI Making health care more affordable SO CHEMICAL & ENGINEERING NEWS LA English DT Article C1 Natl Inst Stand & Technol, Div Analyt Chem, Washington, DC USA. RP Nelson, BC (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Washington, DC USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD MAR 26 PY 2001 VL 79 IS 13 BP 288 EP 288 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 415JD UT WOS:000167717100208 ER PT J AU Coxon, B AF Coxon, B TI Boat conformations. Analysis and simulation of the complex H-1 NMR spectrum of methyl 2,6 : 3,4-dianhydro-alpha-D-altropyranoside (vol 329, pg 131, 2000) SO CARBOHYDRATE RESEARCH LA English DT Correction C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Coxon, B (reprint author), Natl Inst Stand & Technol, Div Biotechnol, 100 Bur Dr Stop 8311, Gaithersburg, MD 20899 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0008-6215 J9 CARBOHYD RES JI Carbohydr. Res. PD MAR 22 PY 2001 VL 331 IS 2 BP 227 EP 228 DI 10.1016/S0008-6215(01)00033-7 PG 2 WC Biochemistry & Molecular Biology; Chemistry, Applied; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA 416VY UT WOS:000167801900015 ER PT J AU Skokov, S Zou, SL Bowman, JM Allison, TC Truhlar, DG Lin, YJ Ramachandran, B Garrett, BC Lynch, BJ AF Skokov, S Zou, SL Bowman, JM Allison, TC Truhlar, DG Lin, YJ Ramachandran, B Garrett, BC Lynch, BJ TI Thermal and state-selected rate coefficients for the O(P-3)+HCl reaction and new calculations of the barrier height and width SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID POTENTIAL-ENERGY SURFACE; CHEMICAL-REACTION RATES; RATE-CONSTANT CALCULATIONS; QUANTUM REACTION DYNAMICS; ATOM-TRANSFER-REACTIONS; PARTIAL CROSS-SECTIONS; PLUS HCL REACTION; TRAJECTORY CALCULATIONS; CONFIGURATION-INTERACTION; COMPUTER-PROGRAM AB This paper compares several approximate methods for calculating rate coefficients for the O(P-3) + HCl reaction to presumably more accurate quantum mechanical calculations that an based on applying the J-shifting approximation (QM/JS) to an accurate cumulative reaction probability for J = O, All calculations for this work employ the recent S4 potential energy surface, which presents a number of challenges for the approximate methods. The O + HCl reaction also poses a significant challenge to computational dynamics because of the heavy-light-heavy mass combination and the broad noncollinear reaction path. The approximate methods for calculating the thermal rate coefficient that are examined in this article are quasiclassical trajectories (QCT), conventional transition state theory (TST), variational transition state theory employing the improved canonical variational theory (ICVT), ICVT with the microcanonical optimized multidimensional tunneling correction (ICVT/mu OMT), and reduced dimensionality quantum mechanical calculations based on adiabatic bend and J-shifting (QM/AB-JS) approximations. It is seen that QCT, TST, and ICVT rate coefficients agree with each other within a factor of 2.7 at 250 K and 1.6 at 1000 K, whereas inclusion of tunneling by the ICVT/mu OMT, QM/AB-JS, or QM/JS methods increases the late coefficients considerably. However, the ICVT/mu OMT and QM/AB-JS methods yield significantly lower rate coefficients than the QM/JS calculations, especially at lower temperatures. We also report and discuss calculations for the state-selected reaction of O(P-3) with HCl in the first excited vibrational state. In addition to the dynamics calculations, we report new electronic structure calculations by the Multi-Coefficient Gaussian-3 (MCG3) method that indicate that one possible source of disagreement between the QM/JS rate coefficients and experiment is that the barrier on the S4 surface may be too narrow. C1 Emory Univ, Dept Chem, Atlanta, GA 30322 USA. Natl Inst Stand & Technol, Expt Kinet & Thermodynam Grp, Gaithersburg, MD 20899 USA. Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. Univ Minnesota, Inst Supercomp, Minneapolis, MN 55455 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Bowman, JM (reprint author), Emory Univ, Dept Chem, 1515 Pierce Dr, Atlanta, GA 30322 USA. RI Garrett, Bruce/F-8516-2011; Truhlar, Donald/G-7076-2015; OI Truhlar, Donald/0000-0002-7742-7294; Ramachandran, Bala/0000-0002-5179-5750 NR 89 TC 19 Z9 19 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 22 PY 2001 VL 105 IS 11 BP 2298 EP 2307 DI 10.1021/jp003783j PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 413VN UT WOS:000167632400023 ER PT J AU Nalli, NR Smith, WL Huang, B AF Nalli, NR Smith, WL Huang, B TI Quasi-specular model for calculating the reflection of atmospheric-emitted infrared radiation from a rough water surface SO APPLIED OPTICS LA English DT Article ID SEA-SURFACE; TEMPERATURE; OCEAN; EMISSIVITY; WINDOW; MU AB A numerical model is developed for computation of the reflection of atmospheric-emitted IR radiance from a wind-roughened water body. The model assumes the Kirchhoff approximation for rough surface scattering. This allows application of the postulates of geometrical optics to determine the reflection of rays from an ensemble of wave facets. We;performed the hemispherical integration with Gaussian quadrature by using an uplooking fast transmittance model. This calculation is simplified further through the concept of a reflection-diffusivity angle. The model compares favorably with observed radiance spectra obtained from the Marine-Atmospheric Emitted Radiance Interferometer during the Combined Sensor Program research cruise. (C) 2001 Optical Society of America. C1 Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI 53706 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Nalli, NR (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, Washington, DC 20233 USA. RI Nalli, Nicholas/F-6731-2010 OI Nalli, Nicholas/0000-0002-6914-5537 NR 36 TC 15 Z9 15 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD MAR 20 PY 2001 VL 40 IS 9 BP 1343 EP 1353 DI 10.1364/AO.40.001343 PG 11 WC Optics SC Optics GA 413RX UT WOS:000167626700006 PM 18357120 ER PT J AU Tumlinson, J Giroux, ML Shull, JM AF Tumlinson, J Giroux, ML Shull, JM TI Probing the first stars with hydrogen and helium recombination emission SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; intergalactic medium; stars : early-type ID LYMAN-ALPHA FOREST; HIGH-REDSHIFT; HOT STARS; MASS-LOSS; EVOLUTION; REIONIZATION; GALAXIES; ULTRAVIOLET; DENSITY AB Unusual patterns of recombination emission from gas ionized by metal-free stars may distinguish early star-forming galaxies from their present-day counterparts. This pattern arises from the harder ionizing spectrum expected from metal-free stars, which strongly enhances the strength of He ii recombination lines. Our calculations indicate that line fluxes of He II lambda 1640 and lambda 4686 are sufficiently large to be detected by narrowband and spectroscopic searches for high-redshift emission-line sources at z less than or similar to 5 using current instruments. Beyond z similar to 5, potentially low stellar mass loss and observational limitations may hinder the detectability of Population III 5 stars with this technique. An unknown fraction of Ly alpha emitters may harbor low-metallicity or metal-free stars. As the predicted He II lambda 1640 flux is comparable to and may exceed hydrogen Ly alpha, searches for high-redshift galaxies should consider He II recombination lines as possible identifications for single emission lines in observed spectra. Spectra of metal-free stars may show both H I and He II emission lines, improving the constraints on their redshift and identification. We assess the considerable uncertainties that affect our expectations for the detection and identification of true first-generation stars with present search techniques, including the role of stellar mass loss in spectral evolution and the confusion of ionization by primordial stellar sources and active galactic nuclei in the early universe. C1 Univ Colorado, Dept Astrophys & Planetary Sci, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO USA. RP Tumlinson, J (reprint author), Univ Colorado, Dept Astrophys & Planetary Sci, Ctr Astrophys & Space Astron, CB 389, Boulder, CO 80309 USA. EM tumlinso@casa.colorado.edu; giroux@casa.colorado.edu; mshull@casa.colorado.edu NR 29 TC 61 Z9 61 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 2001 VL 550 IS 1 BP L1 EP L5 DI 10.1086/319477 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 413GZ UT WOS:000167605400001 ER PT J AU Martner, BE Moran, KP AF Martner, BE Moran, KP TI Using cloud radar polarization measurements to evaluate stratus cloud and insect echoes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERIC RADIATION; PROFILING RADAR; PROGRAM AB Suspended insects and other nonhydrometeor particulates are commonly detected in and near the planetary boundary layer by high-sensitivity millimeter-wave cloud radars, Radar reflectivity patterns of these targets are difficult to discern from those of stratus clouds, and therefore these particles represent undesirable contaminants for automated cloud-detection algorithms. Radar polarization measurements, however, offer a means of distinguishing between cloud droplets and these contaminants, based on the shape information contained in depolarization ratio observations. A procedure is presented which allows dual-polarization cloud radar data and simultaneous lidar and laser ceilometer data to determine the presence of cloud droplets alone, insects alone, and mixtures of the two at the Atmospheric Radiation Measurement program's Cloud and Radiation Test bed sites. Theory is also developed for estimating the contribution of cloud droplets to the observed reflectivity of an insect plus droplet mixture using dual-polarization cloud radar data. Preliminary data indicate that the method provides more accurate estimates if the radar transmits circular rather than linear polarization because the effects of target orientation are minimized. C1 NOAA, ETL, Boulder, CO 80303 USA. RP Martner, BE (reprint author), NOAA, ETL, 325 Broadway, Boulder, CO 80303 USA. NR 12 TC 9 Z9 9 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 16 PY 2001 VL 106 IS D5 BP 4891 EP 4897 DI 10.1029/2000JD900623 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 411DM UT WOS:000167482900015 ER PT J AU Wagner, T Leue, C Pfeilsticker, K Platt, U AF Wagner, T Leue, C Pfeilsticker, K Platt, U TI Monitoring of the stratospheric chlorine activation by Global Ozone Monitoring Experiment (GOME) OClO measurements in the austral and boreal winters 1995 through 1999 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OPTICAL-ABSORPTION SPECTROSCOPY; POLAR VORTEX CONDITIONS; ANTARCTIC OZONE; ARCTIC WINTER; LIDAR OBSERVATIONS; SAM-II; INTERHEMISPHERIC DIFFERENCES; VISIBLE SPECTROSCOPY; MLS OBSERVATIONS; SAGE-II AB Measurements of OClO total column amounts by means of the Global Ozone Monitoring Experiment (GOME) instrument conducted in the austral and boreal winter stratospheres from 1995 through 1999 are presented. GOME is a four-channel UV/visible spectrometer (240-790 nm) deployed on the polar orbiting European ERS-2 satellite since April 1995. Previous studies have shown that the observations of OClO, the symmetric chlorine dioxide formed in a side channel of the reaction of BrO + ClO, can serve as an indicator for a stratospheric chlorine activation. GOME's 3-day coverage of the global atmosphere allows us to infer the first global data set of OClO, and to study continuous time series of its occurrence in both winter stratospheres. It is found that, while OClO regularly occurs over Antarctica in similar amounts and seasonal timing during the different winters, its occurrence is much more variable in the Arctic winter stratosphere, primarily because of the larger dynamic activity that result in warmer temperatures there. About 40% higher OClO column amounts are found in the Antarctic polar stratosphere than in its northern counterpart, a further indication for a significantly more efficient chlorine activation in the Antarctic than the Arctic late winter and spring stratosphere. C1 Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Wagner, T (reprint author), Univ Heidelberg, Inst Umweltphys, Neuenheimer Feld 229, D-69120 Heidelberg, Germany. NR 90 TC 32 Z9 32 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 16 PY 2001 VL 106 IS D5 BP 4971 EP 4986 DI 10.1029/2000JD900458 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 411DM UT WOS:000167482900021 ER PT J AU Poskrebyshev, GA Neta, P Huie, RE AF Poskrebyshev, GA Neta, P Huie, RE TI Equilibrium constant of the reaction OH+HNO3 reversible arrow H2O+NO3 center dot in aqueous solution SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NITRIC-ACID SOLUTIONS; PULSE-RADIOLYSIS; PEROXYNITROUS ACID; NO3 RADICALS; NIGHTTIME CHEMISTRY; ORGANIC REDUCTANTS; HYDROXYL RADICALS; ELECTRON-TRANSFER; HYDROGEN-ATOMS; GAS-PHASE AB The equilibrium reaction .OH + HNO3 reversible arrow H2O + NO3. was investigated by pulse radiolysis in aqueous solutions. An estimate of the equilibrium constant was derived from the dependence of the optical absorbance due to NO3. radicals upon the concentration of HNO3. In addition, estimates of the forward and reverse rate constants were obtained from the dependence of the formation rate constant on the ratio of the activities of nitric acid and water. Studies were carried out at different values of the dose per pulse and at pH values of 1 and 0. The observations were modeled, faking into account all relevant reactions for the formation and decay of the nitrate radical. From these modeling studies the estimated rate and equilibrium constants were refined. The rate constant of the forward reaction is found to be (8.6 +/- 1.3) x 10(7) L mol(-1) s(-1), the rate constant of the reverse reaction is found to be (3 +/- 1) X 10(2) L mol(-1) s(-1), and the equilibrium constant K-eq = (2.8 +/- 0.4) x 10(5), all at zero ionic strength. From the latter value of K-eq and taking E-0(H+,(OH)-O-./H2O) = 2.72 V versus NHE, we calculate the reduction potentials E-0(H+, NO3-/HNO3) = (2.40 +/- 0.01) V and E-0(NO3./NO3-) = (2.48 +/- 0.01) V. This value of the reduction potential for this couple leads to a Henry`s law coefficient of K-H = 0.018 mol L-1 bar(-1) at 298 K for NO3.. This value suggests that the impact of NO3. on atmospheric droplets will be due solely to reactive uptake. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Poskrebyshev, GA (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Huie, Robert/A-5645-2010; Poskrebyshev, Gregory/I-9122-2016 OI Poskrebyshev, Gregory/0000-0002-8920-7037 NR 60 TC 18 Z9 18 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 16 PY 2001 VL 106 IS D5 BP 4995 EP 5004 DI 10.1029/2000JD900702 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 411DM UT WOS:000167482900023 ER PT J AU Guttman, CM Wetzel, SJ Blair, WR Fanconi, BM Girard, JE Goldschmidt, RJ Wallace, WE VanderHart, DL AF Guttman, CM Wetzel, SJ Blair, WR Fanconi, BM Girard, JE Goldschmidt, RJ Wallace, WE VanderHart, DL TI NIST-sponsored interlaboratory comparison of polystyrene molecular mass distribution obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: Statistical analysis SO ANALYTICAL CHEMISTRY LA English DT Article ID GEL-PERMEATION CHROMATOGRAPHY; DESORPTION IONIZATION; POLYDISPERSE POLYMERS; SYNTHETIC-POLYMERS; WEIGHT DISTRIBUTION; IONS; DISCRIMINATION; FRACTIONATION; SPECTRA; ISSUES AB The method of preparation and methods of analysis of a narrow distribution polystyrene of similar to7 ku used in an interlaboratory comparison of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) of synthetic polymers is described. Size exclusion chromatography was used to measure the polystyrene sample variability. Fourier transform infrared spectroscopy and MALDI-TOF-MS were used to analyze end groups on the polymer. The polystyrene was analyzed by MALDI-TOF-MS and classical methods of polymer characterization. The number (M-n) and mass (M-w) average of the molecular mass distribution (MMD) determined by the classical methods (light scattering and NMR) were compared with those obtained by MALDI-TOF-MS. Agreement between classical methods to obtain the moments of the MMD and the MALDI is found to be good overall. However, all the experimental values obtained by MALDI fell below the classical values. A discussion of why these values are lower is included. We discuss the statistical analysis of the data from the interlaboratory comparison conducted by NIST, which includes data from 23 different laboratories. Analysis of variance is used to examine the influences of the independent parameters (laboratory, matrix, instrument manufacturer, instrument mode) on the data. The parameters, laboratory and instrument manufacturer, were determined to have an influence on the MMD, where matrix and instrument mode were found not to have a significant influence. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. American Univ, Dept Chem, Washington, DC 20016 USA. RP Wetzel, SJ (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 34 TC 50 Z9 50 U1 1 U2 7 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 MAR 15 PY 2001 VL 73 IS 6 BP 1252 EP 1262 DI 10.1021/ac001011d PG 11 WC Chemistry, Analytical SC Chemistry GA 412GJ UT WOS:000167546400028 ER PT J AU Thodesen, J Storebakken, T Shearer, KD Rye, M Bjerkeng, B Gjerde, B AF Thodesen, J Storebakken, T Shearer, KD Rye, M Bjerkeng, B Gjerde, B TI Genetic variation in mineral absorption of large Atlantic salmon (Salmo salar) reared in seawater SO AQUACULTURE LA English DT Article DE genetic variation; element-mineral; absorption-digestibility; Atlantic salmon (Salmo salar) ID RAINBOW-TROUT; FEED-UTILIZATION; WHOLE-BODY; GROWTH; ZINC; DIETS; FISH; GAIRDNERI; ELEMENTS; PROTEIN AB Apparent absorption coefficients (AACs) of mineral elements (K, Na, Cu, Ca, Mg, Zn, Fe, Mn, P) were studied in 82 full-sib family groups of individually tagged Atlantic salmon (41 sires, 2 dams per sire, 7-27 fish per family), with an average weight of 4.6 kg. The fish were kept in one net-pen in seawater and fed a diet with Y2O3 as the inert marker. Faeces were obtained by stripping and pooled for each family. The mean AACs (%) of elements and ash were: K, 97.5; Na, 23.8; Cu, 55.9; Ca, - 11.7; Mg, -260; Zn, 37.9; Fe, 23.8; Mn, 7.6; P, 40.4 and ash, 16.6. Differences between paternal half-sib families were significant (P < 0.05) for the AACs of K, Ca, Mg, Zn and Fe. The sire component explained 54-81% of the variation in the AACs of the elements and 60% of the variation in the AAC of ash. The AACs of all elements, except K, were significantly correlated with AAC of ash. The AACs of Cu and Mg were positively correlated to the mean weight of each family. The AAC of Mg was positively correlated while those of K and Zn were negatively correlated to specific growth rate. The results indicate genetic variation in AACs of elements in Atlantic salmon. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Agr Res Council Norway, Inst Aquaculture Res, N-6600 Sunndalsora, Norway. Inst Aquaculture Res, N-1432 As Nlh, Norway. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Storebakken, T (reprint author), Agr Res Council Norway, Inst Aquaculture Res, N-6600 Sunndalsora, Norway. RI storebakken, trond/E-8050-2011 OI storebakken, trond/0000-0002-4525-2098 NR 30 TC 13 Z9 13 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD MAR 15 PY 2001 VL 194 IS 3-4 BP 263 EP 271 DI 10.1016/S0044-8486(00)00525-1 PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 403AW UT WOS:000167021200006 ER PT J AU Newman, PA Wilson, JC Ross, MN Brock, CA Sheridan, PJ Schoeberl, MR Lait, LR Bui, TP Loewenstein, M Podolske, JR AF Newman, PA Wilson, JC Ross, MN Brock, CA Sheridan, PJ Schoeberl, MR Lait, LR Bui, TP Loewenstein, M Podolske, JR TI Chance encounter with a stratospheric kerosene rocket plume from Russia over California SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AEROSOL; MIDLATITUDES; TROPOSPHERE; VORTEX; OZONE AB A high-altitude aircraft flight on April 18, 1997, detected an enormous aerosol cloud at 20 km altitude near California (37 degreesN). Not visually observed, the cloud had high concentrations of soot and sulfate aerosol, and was over 180 km in horizontal extent. The cloud was probably a large hydrocarbon-fueled rocket vehicle, most likely burning liquid oxygen and kerosene. One of two Russian Soyuz rockets could have produced the cloud: a launch from the Baikonur Cosmodrome, Kazakhstan on April 6; or one from Plesetsk, Russia on April 9. Parcel trajectories and long-lived trace gas concentrations suggest the Baikonur launch as the cloud source. Cloud trajectories do not trace the Soyuz plume from Asia to North America, illustrating the uncertainties of point-to-point trajectories. This cloud encounter is the only stratospheric measurement of a hydrocarbon-fueled rocket. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Denver, Dept Engn, Denver, CO 80208 USA. Aerospace Corp, Environm Syst Directorate, Los Angeles, CA 90009 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Raytheon ITSS, Lanham, MD USA. RP Newman, PA (reprint author), NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. RI Brock, Charles/G-3406-2011; Newman, Paul/D-6208-2012 OI Brock, Charles/0000-0002-4033-4668; Newman, Paul/0000-0003-1139-2508 NR 15 TC 9 Z9 9 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 15 PY 2001 VL 28 IS 6 BP 959 EP 962 DI 10.1029/2000GL011972 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 411JD UT WOS:000167494200003 ER PT J AU Cziczo, DJ Abbatt, JPD AF Cziczo, DJ Abbatt, JPD TI Ice nucleation in NH4HSO4, NH4NO3, and H2SO4 aqueous particles: Implications for cirrus cloud formation SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SULFURIC-ACID AEROSOLS; PHASE-TRANSITIONS; LOW-TEMPERATURE; SULFATE; FTIR AB The temperature at which ice nucleation occurs in aqueous NH4HSO4, NH4NO3, and H2SO4 particles has been studied as a function of solute concentration. The onset of freezing was determined using FTIR extinction spectroscopy coupled to a low-temperature flow tube system. The greatest supercooling with respect to equilibrium freezing was observed for H2SO4/H2O. Considerably less supercooling was observed for NH4NO3/H2O, and less yet for the NH4HSO4/H2O system. All three aerosol types exhibit a lower freezing temperature, as a function of solute concentration, than (NH4)(2)SO4 particles previously studied by this approach. These results suggest that air masses containing ammoniated sulfate particles will promote cirrus cloud formation at higher temperatures and lower relative humidities than will those containing pure H2SO4 particles. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Toronto, Dept Chem, Toronto, ON M5S 3H6, Canada. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Cziczo, DJ (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80305 USA. NR 20 TC 21 Z9 21 U1 3 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 15 PY 2001 VL 28 IS 6 BP 963 EP 966 DI 10.1029/2000GL012568 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 411JD UT WOS:000167494200004 ER PT J AU Ezer, T AF Ezer, T TI Can long-term variability in the Gulf Stream transport be inferred from sea level? SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NORTH-ATLANTIC OCEAN; INTERPENTADAL VARIABILITY; MODEL AB Recent studies by Sturges and collaborators suggest a simple, but powerful, technique to estimate climatic changes in the transport of the Gulf Stream from the difference between the oceanic sea level calculated with a simple wind-driven Rossby wave model and the observed coastal sea level. The hypothesis behind this technique is tested, using 40 years of data (1950 to 1989) obtained from a three-dimensional Atlantic Ocean model forced by observed surface data. The analysis shows that variations in sea level difference between the ocean and the coast are indeed coherent with variations of the Gulf Stream transport for periods shorter than 1 year or longer than 4-5 years. The results obtained from the three-dimensional model confirm the findings of the simple Rossby wave model that decadal climatic changes in the Gulf Stream transport vary considerably with latitude. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Ezer, T (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, POB CN710,Sayre Hall, Princeton, NJ 08544 USA. OI Ezer, Tal/0000-0002-2018-6071 NR 13 TC 20 Z9 20 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 15 PY 2001 VL 28 IS 6 BP 1031 EP 1034 DI 10.1029/2000GL011640 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 411JD UT WOS:000167494200021 ER PT J AU Katsaros, KB Forde, EB Chang, P Liu, WT AF Katsaros, KB Forde, EB Chang, P Liu, WT TI QuikSCAT's SeaWinds facilitates early identification of tropical depressions in 1999 hurricane season SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SCATTEROMETER; SYSTEM; OCEAN AB Far from land and surface ship observations, most tropical depressions are identified by examining images from geostationary satellites for the presence of rotation of the convective cloud masses. During the 1999 hurricane season, surface wind vectors obtained by the SeaWinds scatterometer on the QuikSCAT satellite for the tropical Atlantic and Caribbean Sea were examined to test the hypothesis that developing tropical depressions (TDs) could be observed with this satellite sensor, before identification by the traditional means. QuikSCAT was able to detect the presence of closed circulation in the surface winds before the systems were designated as depressions. The satellite's unprecedented large swath width of 1800 km allows twice a day observation of most of the tropical oceans. SeaWinds data can, therefore, provide valuable guidance that are an important addition to the tools available to the tropical cyclone forecasting community. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Camp Springs, MD 20746 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Katsaros, KB (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Chang, Paul/F-5580-2010 OI Chang, Paul/0000-0001-5113-0938 NR 16 TC 49 Z9 50 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 MAR 15 PY 2001 VL 28 IS 6 BP 1043 EP 1046 DI 10.1029/2000GL011646 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 411JD UT WOS:000167494200024 ER PT J AU Murphy, PP Nojiri, Y Harrison, DE Larkin, NK AF Murphy, PP Nojiri, Y Harrison, DE Larkin, NK TI Scales of spatial variability for surface ocean pCO(2) in the Gulf of Alaska and Bering Sea: toward a sampling strategy SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NORTH PACIFIC; SOUTH-PACIFIC; CO2; FLUX AB Twenty-four near-exact repeat tracks lover a 48-month period) of ocean surface pCO(2) data from the North Pacific offer an unprecedented opportunity to examine the space scales of pCO(2) in this region. Because previous basin scale studies of air-sea carbon flux have shown that the field of Delta pCO(2) lair-sea disequilibrium) largely controls the field of flux land atmospheric pCO(2) is relatively constant), knowing how to sample pCO(2) in seawater is a crucial element of the design of a basin scale carbon flux observing system. Unbiased (within 3 mu atm) along-track means for Delta pCO(2) can be obtained from measurements made every 40 km (similar to hourly for a ship traveling 20 knots). We find distinctly different characteristics of spatial variability in two open ocean regions, the Bering Sea and the Gulf of Alaska. The first zero crossing of the mean spatial autocorrelation function is 1.5 degrees longitude in the Bering Sea and 3.5 degrees in the Gulf of Alaska, when the cruise data are linearly detrended to remove the larger scale field. There is a strong seasonal variation in the zero crossing, with shorter scales in the summer. In near-shore waters there is extreme variability, often with very small space scales and very large cruise-to-cruise differences. Neither the mean nor variability statistics from a single ship cruise data set appear likely to produce reliable information for designing an observing system. C1 NOAA, Natl Oceanog Data Ctr, Silver Spring, MD USA. Natl Inst Environm Studies, Tsukuba, Ibaraki, Japan. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Murphy, PP (reprint author), NOAA, Natl Oceanog Data Ctr, Silver Spring, MD USA. RI Harrison, Don/D-9582-2013; Nojiri, Yukihiro/D-1999-2010 OI Nojiri, Yukihiro/0000-0001-9885-9195 NR 11 TC 15 Z9 17 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 15 PY 2001 VL 28 IS 6 BP 1047 EP 1050 DI 10.1029/2000GL012375 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 411JD UT WOS:000167494200025 ER PT J AU Harrison, DE Vecchi, GA AF Harrison, DE Vecchi, GA TI El Nino and La Nina - Equatorial Pacific thermocline depth and sea surface temperature anomalies, 1986-98 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MADDEN-JULIAN OSCILLATION; TROPICAL PACIFIC; SOUTHERN OSCILLATION; MODEL; VARIABILITY; ENSO; EVENTS AB Simple models of the El Nino-Southern Oscillation (ENSO) phenomenon have provided many of our basic ideas about ENSO mechanisms. These models exhibit a range of correlation patterns between thermocline depth anomaly (Z(20)A) and sea surface temperature anomaly (SSTA). We use 13 years of Pacific equatorial waveguide observations to explore the relationships between Z(20)A and SSTA. We find significant correlation in the eastern Pacific, and in the east-central Pacific when the east-central Pacific is normal or cooler than normal. We find no correlation in the western, west-central and east-central (when warmer than normal) Pacific. It is inappropriate to attribute SSTA changes to Z(20)A changes. Coupled ENSO models should be reexamined in light of these observed Z(20)A/SSTA relationships. Analysis of ocean general circulation models suggests that progress in understanding ENSO may depend as much on understanding SSTA/wind/near-surface current relationships and processes, as upon thermocline change processes. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98115 USA. Univ Washington, Sch Oceanog, Seattle, WA 98115 USA. RP Harrison, DE (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI Vecchi, Gabriel/A-2413-2008; Harrison, Don/D-9582-2013 OI Vecchi, Gabriel/0000-0002-5085-224X; NR 26 TC 26 Z9 27 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 MAR 15 PY 2001 VL 28 IS 6 BP 1051 EP 1054 DI 10.1029/1999GL011307 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 411JD UT WOS:000167494200026 ER PT J AU Fernandez, J Charco, M Tiampo, KF Jentzsch, G Rundle, JB AF Fernandez, J Charco, M Tiampo, KF Jentzsch, G Rundle, JB TI Joint interpretation of displacement and gravity data in volcanic areas. A test example: Long Valley Caldera, California SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADAR INTERFEROMETRY; MAGMA INTRUSION; HALF-SPACE; DEFORMATION; INFLATION; COLLAPSE; ERUPTION; CHAMBER; SURFACE; UPLIFT AB Volcanic activity produces deformation and gravity changes that many times can be used as precursors of future eruptions. Applying geodetic techniques to monitoring activity involves interpretation using deformation models. Usually gravity change data and displacement data are interpreted separately. We show, using modeling of deformation and gravity change data in Long Valley Caldera, California, USA, that this can lead to incorrect interpretations. The results obtained show that displacements and gravity changes must be interpreted together whenever possible and that elastic-gravitational models can be a far more appropriate approximation to problems of volcanic load in the crust than the more commonly used purely elastic models. Therefore it is necessary to change the philosophy normally used to interpret geodetic observations, improving the possibility of predicting future eruptions. C1 Univ Complutense Madrid, Fac C Matemat, CSIC, Inst Astron & Geodesia, E-28040 Madrid, Spain. FSU Jena, Inst Geosci, Dept Geol & Geophys, D-07749 Jena, Germany. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Fernandez, J (reprint author), Univ Complutense Madrid, Fac C Matemat, CSIC, Inst Astron & Geodesia, Ciudad Univ, E-28040 Madrid, Spain. RI Fernandez, Jose/K-1669-2014; Charco, Maria/L-9823-2014; Tiampo, Kristy/I-1355-2015 OI Fernandez, Jose/0000-0001-5745-3527; Charco, Maria/0000-0001-9281-8392; Tiampo, Kristy/0000-0002-5500-7600 NR 32 TC 15 Z9 15 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 MAR 15 PY 2001 VL 28 IS 6 BP 1063 EP 1066 DI 10.1029/2000GL012393 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 411JD UT WOS:000167494200029 ER PT J AU Thompson, WE Jacox, ME AF Thompson, WE Jacox, ME TI The infrared spectra of the NH3-d(n)(+) cations trapped in solid neon SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ION PHOTOELECTRON-SPECTROSCOPY; VIBRATIONAL-SPECTRA; MOLECULAR-IONS; LASER SPECTROSCOPY; AB-INITIO; ENERGY-LEVELS; OSCILLATOR-STRENGTHS; ELECTRON AFFINITIES; CROSS-SECTIONS; GROUND-STATE AB When a dilute mixture of NH3 in neon is subjected to Penning ionization and/or photoionization by neon atoms in their first excited states, between 16.6 eV and 16.85 eV, and the products are rapidly frozen at approximately 5 K, the infrared spectrum of the resulting deposit includes three relatively prominent product absorptions which agree well with the positions determined in earlier gas-phase studies for the three infrared-active fundamentals of (NH3+)-N-14. The corresponding fundamentals of (NH3+)-N-15, (ND3+)-N-14, and (ND3+)-N-15 have been observed for the first time, as have been many of the fundamentals of the partially deuterium-substituted cations, in experiments on isotopically enriched NH3 samples. When the effects of anharmonicity are considered (including the occurrence of "negative anharmonicity" for the out-of-plane deformation fundamental), the positions of these absorptions agree satisfactorily with those predicted in an earlier study from the fit of an ab initio potential surface to the experimental data for (NH3+)-N-14, as well as with those predicted in the present study from a least-squares force constant adjustment to the frequencies observed for the various isotopomers. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. US Dept Commerce, Technol Adm, Natl Inst Stand & Technol, Washington, DC 20230 USA. RP Thompson, WE (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 87 TC 17 Z9 17 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 15 PY 2001 VL 114 IS 11 BP 4846 EP 4854 DI 10.1063/1.1349087 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 409DC UT WOS:000167368400012 ER PT J AU Applegate, BE Miller, TA Barckholtz, TA AF Applegate, BE Miller, TA Barckholtz, TA TI The Jahn-Teller and related effects in the cyclopentadienyl radical. I. The ab initio calculation of spectroscopically observable parameters SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONICAL INTERSECTION MECHANISM; RESOLVED ELECTRONIC-SPECTRUM; SPIN RESONANCE; SMALL CLUSTERS; RESOLUTION; MOLECULES; SOLVATION; CHEMISTRY; SOLVENTS; SYSTEM AB Ab initio calculations are performed for the (X) over tilde E-2(1)" and (A) over tilde (2)A(2)" states of the cyclopentadienyl radical. An important goal of these calculations is to guide the analysis of the experimentally observed (A) over tilde (2)A(2)"- (X) over tilde E-2(1)" electronic spectrum. Vibrational frequencies for both the (X) over tilde and (A) over tilde state are reported. Large changes in frequency between the states for out-of-plane vibrations are found, leading to the expectation that overtones of these modes will appear strongly in the spectrum. Additionally, spectroscopically obtainable parameters describing the Jahn-Teller effect are calculated for the (X) over tilde state. Using all this information the (X) over tilde-(A) over tilde electronic spectrum is predicted for both C5H5 and C5D5. (C) 2001 American Institute of Physics. C1 Ohio State Univ, Dept Chem, Laser Spect Facil, Columbus, OH 43210 USA. Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Ohio State Univ, Dept Chem, Laser Spect Facil, 120 W 18th Ave, Columbus, OH 43210 USA. EM tamiller+@osu.edu RI Miller, Terry/F-6607-2014 OI Miller, Terry/0000-0003-0731-8006 NR 45 TC 60 Z9 60 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 15 PY 2001 VL 114 IS 11 BP 4855 EP 4868 DI 10.1063/1.1348275 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 409DC UT WOS:000167368400013 ER PT J AU Phelan, BA Manderson, JP Stoner, AW Bejda, AJ AF Phelan, BA Manderson, JP Stoner, AW Bejda, AJ TI Size-related shifts in the habitat associations of young-of-the-year winter flounder (Pseudopleuronectes americanus): field observations and laboratory experiments with sediments and prey SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE burying; food; habitat; sediment; substrata; winter flounder ID PLEURONECTES-PLATESSA L; PARALICHTHYS-DENTATUS; SPATIAL VARIATION; BURYING ABILITY; GROWTH-RATES; GRAIN-SIZE; BODY-SIZE; JUVENILE; FLATFISHES; PREFERENCE AB Field surveys and laboratory studies were used to determine the role of substrata in habitat selection by young-of-the year winter flounder. A synoptic field survey of winter flounder and sediments in the Navesink River-Sandy Hook Bay estuarine system in New Jersey demonstrated that winter flounder distribution was related to sediment grain size. Analysis using a generalized additive model indicated that the probability of capturing 10-49 mm SL winter flounder was high on sediments with a mean grain diameter of less than or equal to 0.5 mm, while fish 50-95 mm were least likely to be collected on fine sediments and most commonly on sediments with a grain-size near 1.0 mm. In the laboratory, sediment preferences and the burying ability of winter flounder (15-69 mm SL) were tested by exposing fish in 10-mm size groups to a choice of azoic sediments of different sediment grain sizes. Smaller individuals ( < 40 mm SL) preferred fine-grained sediments while larger individuals ( 40 mm SL) preferred coarse-grained sediments. Burying ability increased with size and all flounders avoided sediments that prevented burial. Subsequent laboratory experiments revealed that the presence of live prey (Mya arenaria) can over-ride sediment choice by winter flounder (50-68 mm SL) indicating the complexity of interrelated factors in habitat choice. (C) Published by Elsevier Science B.V. C1 James J Howard Marine Sci Lab, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Behav Ecol Branch, Highlands, NJ 07732 USA. RP Phelan, BA (reprint author), James J Howard Marine Sci Lab, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Behav Ecol Branch, 74 Magruder Rd, Highlands, NJ 07732 USA. NR 47 TC 52 Z9 53 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD MAR 15 PY 2001 VL 257 IS 2 BP 297 EP 315 DI 10.1016/S0022-0981(00)00340-3 PG 19 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 414BV UT WOS:000167646800010 ER PT J AU Vandemark, D Mourad, PD Bailey, SA Crawford, TL Vogel, CA Sun, J Chapron, B AF Vandemark, D Mourad, PD Bailey, SA Crawford, TL Vogel, CA Sun, J Chapron, B TI Measured changes in ocean surface roughness due to atmospheric boundary layer rolls SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SYNTHETIC-APERTURE-RADAR; COLD-AIR OUTBREAK; SEA-SURFACE; WIND FIELDS; IMAGERY; SATELLITE; SAR; TURBULENCE; WAVES AB A research aircraft was recently flown over the Mid-Atlantic Eight during a mild cold air outbreak to sample the planetary boundary layer at low levels of 15-20 m above the sea surface. Aircraft sensors measured near-surface atmospheric turbulence and, at the same time, variations in sea surface roughness using laser and radar. The aircraft turbulence observations indicate a coherent secondary flow consistent with boundary layer roll vortices of crosswind scale 1.5-2.0 km. Modulation in measured laser and radar-inferred sea surface slope variance occurs at similar scales. Remarkable correlation is found between the radar backscatter and near-surface wind speed data, showing that the short wave slope variance is responsive to these large eddies. Associated small but periodic changes in wind direction do not appear to impact the short wave slope signature. Differentiation between short- and intermediate-scale wave roughness using aircraft laser and radar data leads us to conclude that observed fluctuations in intermediate-scale wave slope were not directly linked to the local wind. A synthetic aperture radar (SAR) image was acquired by the Canadian Space Agency's RADARSAT coincident with the aircraft measurements. Widespread streaking in the SAR image suggests the surface impacts of atmospheric longitudinal rolls. Our aircraft results indicate that the dominant term dictating SAR backscatter modulations at the eddy scale of 1-2 km is the fluctuation of the along-wind velocity, nominally associated with regions of near-surface convergence or divergence. Wind speed fluctuations of 7-10% estimated from the SAR and aircraft radar are consistent with the aircraft's measured variations in near-surface wind speed. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Isl, VA 23337 USA. Univ Washington, Coll Ocean & Fishery Sci, Appl Phys Lab, Seattle, WA 98105 USA. NOAA, Appl Res Lab, Field Res Div, Idaho Falls, ID 83402 USA. NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. IFREMER, Ctr Brest, F-29280 Plouzane, France. RP Vandemark, D (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Isl, VA 23337 USA. EM vandemark@gsfc.nasa.gov RI Sun, Jielun/H-6576-2015; Chapron, Bertrand/O-6527-2015 OI Sun, Jielun/0000-0003-3271-7914; NR 31 TC 16 Z9 17 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 2001 VL 106 IS C3 BP 4639 EP 4654 DI 10.1029/1999JC000051 PG 16 WC Oceanography SC Oceanography GA 409WX UT WOS:000167409600022 ER PT J AU Gonzalez, C Lim, EC AF Gonzalez, C Lim, EC TI Ab initio study of the intermolecular interactions in small benzene clusters: The equilibrium structures of trimer, tetramer, and pentamer SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MOLECULAR MECHANICS; ENERGY MINIMIZATION; NAPHTHALENE TRIMER; ELECTRONIC-SPECTRA; QUANTUM-CHEMISTRY; ANTHRACENE DIMER; GROUND-STATE; HYDROCARBONS; SPECTROSCOPY; CONFORMATION AB Correlated (MP2) calculations with 6-31G and 6-31G* basis sets have been used to probe the equilibrium geometries of the benzene trimer, tetramer, and pentamer. The lowest energy configuration was found to be a trigonal C-3h structure for the trimer and a tetrahedral C-3 structure for the tetramer. For the pentamer, the MP2/6-31G calculation yields the lowest energy structure, which is a trigonal bipyramid (C-3h) In the tetramer and pentamer, the fourth and fifth benzene molecules occupy the apex of the trigonal bipyramid with their molecular plane perpendicular to the 3-fold symmetry axis of the cyclic trimer motif. These structures, which maximize nearest-neighbor coordination number, suggest manifestation of the Wefelmeier growth sequence in benzene clusters. C1 Univ Akron, Dept Chem, Akron, OH 44325 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Lim, EC (reprint author), Univ Akron, Dept Chem, Akron, OH 44325 USA. NR 37 TC 44 Z9 44 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 15 PY 2001 VL 105 IS 10 BP 1904 EP 1908 DI 10.1021/jp0015776 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 413CN UT WOS:000167592500029 ER PT J AU Huber, ME Steinbach, AH Ono, RH AF Huber, ME Steinbach, AH Ono, RH TI Resonance damping in tightly coupled d.c. SQUIDs via intra-coil resistors SO PHYSICA C LA English DT Article DE SQUID; resonance; damping; planar coil; distortion; noise ID DC-SQUID; NOISE; OPTIMIZATION AB Intra-coil damping is demonstrated to be an effective method for reducing resonance structure in well coupled d.c. SQUIDs with large input coils. A resistance of 1 Omega is placed across each turn of a 137 turn coil coupled to a planar washer d.c. SQUID. Non-ideal structure in the voltage-flux curve is greatly reduced, extending the range (in current bias) of satisfactory device operation. The resulting flux noise, while higher than the thermal noise limit, is less than that observed in undamped devices and can be predicted with a simple model. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, Dept Phys, Denver, CO 80217 USA. Natl Inst Stand & Technol, Div Electromagnet Technol, Boulder, CO 80303 USA. Univ Colorado, Dept Phys, Boulder, CO 80303 USA. RP Huber, ME (reprint author), Univ Colorado, Dept Phys, POB 173364, Denver, CO 80217 USA. RI Huber, Martin/B-3354-2011 NR 16 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAR 15 PY 2001 VL 351 IS 2 BP 85 EP 90 DI 10.1016/S0921-4534(00)01627-0 PG 6 WC Physics, Applied SC Physics GA 413XZ UT WOS:000167638000001 ER PT J AU Eggleston, JJ McFadden, GB Voorhees, PW AF Eggleston, JJ McFadden, GB Voorhees, PW TI A phase-field model for highly anisotropic interfacial energy SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article DE phase-field; anisotropy; interfacial energy ID NUMERICAL SIMULATIONS; ORDER-PARAMETER; MEAN-CURVATURE; SOLIDIFICATION; TRANSITIONS; MOTION; ALLOY; EQUATION; KINETICS; GROWTH AB A computationally efficient phase-field model is developed for two-phase systems with anisotropic interfacial energy. The approach allows for anisotropies sufficiently high that the interface has corners or missing crystallographic orientations. The method employs a regularization that enforces local equilibrium at the corners and allows corners to be added or removed without explicitly tracking their location. Numerical simulations for various degrees of anisotropy were performed and they show excellent agreement with analytical equilibrium shapes and yield accurate time dependent solutions for a wide variety of initial conditions. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. EM p-voorhees@nwu.edu RI McFadden, Geoffrey/A-7920-2008; Voorhees, Peter /B-6700-2009 OI McFadden, Geoffrey/0000-0001-6723-2103; NR 31 TC 118 Z9 126 U1 5 U2 36 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 EI 1872-8022 J9 PHYSICA D JI Physica D PD MAR 15 PY 2001 VL 150 IS 1-2 BP 91 EP 103 DI 10.1016/S0167-2789(00)00222-0 PG 13 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 437LK UT WOS:000168993000006 ER PT J AU Bryant, GW Band, YB AF Bryant, GW Band, YB TI T-shaped quantum wires in magnetic fields: Weakly confined magnetoexcitons beyond the diamagnetic limit SO PHYSICAL REVIEW B LA English DT Article ID CLEAVED-EDGE-OVERGROWTH; ONE-DIMENSIONAL EXCITONS; OPTICAL ANISOTROPY; LATERAL CONFINEMENT; BINDING-ENERGY; WAVE-FUNCTIONS; PHOTOLUMINESCENCE; SPECTROSCOPY; OPTIMIZATION; STATES AB Optical excitations of magnetoexcitons in T-shaped wires are calculated and compared with experiment. We find the single-particle states for electrons and holes confined to a wire in a magnetic field and use these states as a basis for calculations of magnetoexciton states. We accurately reproduce the field dependence of the exciton states and explain the small, field-induced, energy shifts that are observed for these states. The shifts are small because the T-junction provides weak confinement, rather than strong quantum confinement. Diamagnetic shifts calculated from perturbation theory fail to describe the experimental results. We determine when perturbation theory is valid for these nanostructures and which gauge should be used to give the diamagnetic shift that best reproduces the held dependence at low fields. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel. Ben Gurion Univ Negev, Dept Phys, IL-84105 Beer Sheva, Israel. RP Bryant, GW (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8423, Gaithersburg, MD 20899 USA. EM garnett.bryant@nist.gov; band@bgumail.bgu.ac.il NR 37 TC 16 Z9 16 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 MAR 15 PY 2001 VL 63 IS 11 AR 115304 DI 10.1103/PhysRevB.63.115304 PG 9 WC Physics, Condensed Matter SC Physics GA 413QT UT WOS:000167623800067 ER PT J AU Akpalu, YA Karim, A Satija, SK Balsara, NP AF Akpalu, YA Karim, A Satija, SK Balsara, NP TI Suppression of lateral phase separation in thin polyolefin blend films SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; POLYMER-FILMS; SPINODAL DECOMPOSITION; DIBLOCK COPOLYMERS; HOMOPOLYMER BLENDS; LIFSHITZ POINT; MIXTURES; SURFACE; COMPATIBILIZERS; MICROEMULSIONS AB The effectiveness of a compatibilizer in suppressing lateral phase separation in thin polyolefin blend films is investigated as a function of film thickness and temperature. Neutron and X-ray reflectivity measurements were made on spun-cast thin blend films of partially deuterated and hydrogenated polyolefin blends with and without diblock compatibilizer. We use an extended silicon surface passivating treatment. Under these biased symmetric wetting conditions (air vs hydrophobic Si), binary blend films are stabilized against both dewetting from the substrate and roughening of the surface due to phase separation when the film thickness (approximate to 25 nm) is on the order of the molecular radius of gyration. However, thicker (approximate to 100 nm) films exhibit lateral phase separation that can be suppressed by the addition of block copolymer compatibilizer. This stabilization effect can be attributed to the reduction of interfacial tension leading to a broadening of interfaces, and additionally, the presence of diblock copolymer in both phases alters their surface interactions. On longer time scales, optical micrographs show the development of large-scale features over the course of a year in the molecularly thin blend films and in the ternary thin film (stored under vacuum). A droplet morphology is observed for molecularly thin blend films, and an interconnected domain structure characteristic of the early and intermediate stages of phase separation is observed for the ternary thin blend film. The phase separated structure obtained for the binary thin blend film does not evolve with time. Our results indicate that one also needs to account for kinetics in order to develop a comprehensive understanding of the structure of thin blend films. In general, temperature has a weak effect on the profile development of compatibilized blend films. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Polytech Univ, Dept Chem Engn, Brooklyn, NY 11201 USA. RP Akpalu, YA (reprint author), Rensselaer Polytech Inst, Dept Chem, New York State Ctr Polymer Synth, Troy, NY 12180 USA. NR 46 TC 18 Z9 18 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAR 13 PY 2001 VL 34 IS 6 BP 1720 EP 1729 DI 10.1021/ma001347p PG 10 WC Polymer Science SC Polymer Science GA 409ET UT WOS:000167372100030 ER PT J AU Ruette, F Gonzalez, C Octavio, A AF Ruette, F Gonzalez, C Octavio, A TI Fundamental properties of parametric functionals in quantum chemistry SO JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM LA English DT Article DE parametric functionals; quantum chemistry; parametric Hamiltonians ID AB-INITIO COMPUTATION; PI-ELECTRON METHODS; CONSISTENT MODIFICATIONS; SIMULATION TECHNIQUES; SEMIEMPIRICAL METHODS; 2ND-ROW ELEMENTS; SINDO1; MODEL; HAMILTONIANS; PERSPECTIVES AB A theoretical interpretation and justification of the basic approaches proposed in parametrical methods is presented in this paper. The idea of providing a fundamental understanding of these methods can be considered as a guide for further development in this area. The application of functional analysis concepts to understanding the nature of parametric functionals in terms of the Riesz and Weiestrass's theorems is discussed. In addition, applications of virial and hypervirial theorems to constrain the type of functional and the parameters used in these methods is addressed. A justification of the use of a single determinantal wavefunction and the nature and conditions of optimized orbital basis in terms of different electronic environments involved in different interactions was also established. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Inst Venezolano Invest Cient, Ctr Quim, Lab Quim Computac, Caracas 1010A, Venezuela. NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. IVIC, Dept Matemat, Caracas, Venezuela. RP Inst Venezolano Invest Cient, Ctr Quim, Lab Quim Computac, Apartado 21827, Caracas 1010A, Venezuela. EM fruette@quimica.ivic.ve NR 47 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 J MOL STRUC-THEOCHEM JI Theochem-J. Mol. Struct. PD MAR 12 PY 2001 VL 537 SI SI BP 17 EP 25 DI 10.1016/S0166-1280(00)00659-X PG 9 WC Chemistry, Physical SC Chemistry GA 399WX UT WOS:000166838200004 ER PT J AU Li, X Pichel, W Maturi, E Clemente-Colon, P Sapper, J AF Li, X Pichel, W Maturi, E Clemente-Colon, P Sapper, J TI Deriving the operational nonlinear multichannel sea surface temperature algorithm coefficients for NOAA-15 AVHRR/3 SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article AB The National Oceanic and Atmospheric Administration (NOAA) currently uses Nonlinear Sea Surface Temperature (NLSST) algorithms to estimate sea surface temperature (SST) from NOAA satellite Advanced Very High Resolution Radiometer (AVHRR) data. In this study, we created a three-month dataset of global sea surface temperature derived from NOAA-15 AVHRR data paired with coincident SST measurements from buoys (i.e. called the SST matchup dataset) between October and December 1998. The satellite sensor SST and buoy SST pairs were included in the dataset if they were coincident within 25 km and 4 hours. A regression analysis of the data in this matchup dataset was used to derive the coefficients for the operational NLSST equations applicable to NOAA-15 AVHRR sensor data. An independent matchup dataset (between January and March 1999) was also used to assess the accuracy of these day and night operational NLSST algorithms. The bias was found to be 0.14 degreesC and 0.08 degreesC for the day and night algorithms, respectively. The standard deviation was 0.5 degreesC or less. C1 NOAA, NESDIS, Camp Springs, MD 20746 USA. RP Li, X (reprint author), NOAA, NESDIS, E-RA3,Room 102 WWBG,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Clemente-Colon, Pablo/F-5581-2010; Maturi, Eileen/F-5611-2010; Pichel, William/F-5619-2010; Li, Xiaofeng/B-6524-2008 OI Pichel, William/0000-0001-6332-0149; Li, Xiaofeng/0000-0001-7038-5119 NR 13 TC 28 Z9 33 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD MAR 10 PY 2001 VL 22 IS 4 BP 699 EP 704 PG 6 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 410FM UT WOS:000167429400013 ER PT J AU Fox, CG Matsumoto, H Lau, TKA AF Fox, CG Matsumoto, H Lau, TKA TI Monitoring Pacific Ocean seismicity from an autonomous hydrophone array SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID DE-FUCA RIDGE; CURRENT PLATE MOTIONS; EARTHQUAKE SWARM; T-WAVES; EVENT AB Since May 1996, an array of autonomous hydrophone moorings has been continuously deployed in the eastern equatorial Pacific to provide long-term monitoring of seismic activity, including low-level volcanic signals, along the East Pacific Rise between 20 degreesN and 20 degreesS and the Galapagos Ridge. The instruments and moorings were designed to continuously record low-frequency acoustic energy in the SOFAR channel for extended periods and produce results comparable to those previously derived by using the U,S. Navy Sound Surveillance SS stem (SOSUS) The technology and methodology developed for this in the northeast Pacific. The technology and methodology developed for this experiment, including instrument design, mooring configuration, analysis software, location algorithms (with an analysis of errors), and a predicted error field, are described in detail. Volcanic activity is observed throughout the Pacific, along with seismicity along transform faults, subduction zones, and intraplate regions. Comparison data sets indicate detection thresholds and accuracy better than the land networks for open ocean areas and results comparable to. or better than, SOSUS, Volcanic seismicity along the fast spreading East Pacific Rise appears similar in the Northeast Pacific but with much shorter durations. to documented examples In One example from the intermediate spreading Galapagos Ridge is comparable to northeast Pacific examples? and several episodes of activity were observed in the Wilkes Transform Fault Zone. A site of continuing off-axis seismicity is located near 18 degreesS and 116 degreesW. Isolated intraplate earthquakes are observed throughout the study area. Earthquake information from this experiment and future observations will be provided through the World Wide Web and earthquake data centers. C1 NOAA, Pacific Marine Environm Lab, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. Oregon State Univ, Hatfield Marine Sci Ctr, NOAA, Cooperat Inst Marine Resources Studies, Newport, OR 97365 USA. RP Fox, CG (reprint author), NOAA, Pacific Marine Environm Lab, Hatfield Marine Sci Ctr, 2115 SE OSU Dr, Newport, OR 97365 USA. EM fox@pmel.noaa.gov; matsumoto@pmel.noaa.gov; lau@pmel.noaa.gov NR 36 TC 126 Z9 126 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 2001 VL 106 IS B3 BP 4183 EP 4206 DI 10.1029/2000JB900404 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 409JA UT WOS:000167379500016 ER PT J AU Holden, MJ Mayhew, MP Gallagher, DT Vilker, VL AF Holden, MJ Mayhew, MP Gallagher, DT Vilker, VL TI Chorismate lyase: Understanding the mechanism of product inhibition SO FASEB JOURNAL LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 8 PY 2001 VL 15 IS 5 BP A1160 EP A1160 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 410TA UT WOS:000167454202577 ER PT J AU Perkins, KK Hanisco, TF Cohen, RC Koch, LC Stimpfle, RM Voss, PB Bonne, GP Lanzendorf, EJ Anderson, JG Wennberg, PO Gao, RS Del Negro, LA Salawitch, RJ McElroy, CT Hintsa, EJ Loewenstein, M Bui, TP AF Perkins, KK Hanisco, TF Cohen, RC Koch, LC Stimpfle, RM Voss, PB Bonne, GP Lanzendorf, EJ Anderson, JG Wennberg, PO Gao, RS Del Negro, LA Salawitch, RJ McElroy, CT Hintsa, EJ Loewenstein, M Bui, TP TI The NOx-HNO3 system in the lower stratosphere: Insights from in situ measurements and implications of the J(HNO3)-[OH] relationship SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID SUMMER POLARIS MISSION; NASA ER-2 AIRCRAFT; REACTIVE NITROGEN; ARCTIC STRATOSPHERE; SOUTHERN-HEMISPHERE; MIDDLE STRATOSPHERE; OZONE LOSS; NO2; CLO; PHOTOCHEMISTRY AB During the 1997 Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) mission, simultaneous in situ observations of NOchi and HOchi radicals, their precursors, and the radiation field were obtained in the lower stratosphere. We use these observations to evaluate the primary mechanisms that control NOchi- HNO3 exchange and to understand their control over the partitioning between NO2 and HNO3 in regions of continuous sunlight. We calculate NOchi production (P-NO chi) and loss (L-NO chi) in a manner directly constrained by the in situ measurements and current rate constant recommendations, using approaches for representing albedo, overhead O-3 and [OH] that reduce model uncertainty. We find a consistent discrepancy of 18% between modeled rates of NOchi production and loss (L-NO chi = 1.18P(NO chi)) which is within the measurement uncertainty of 127%. The partitioning between NOchi production processes is [HNO3 + OH (41 +/- 2)%; HNO3 + hv (59 +/- 2)%] and between NOchi loss processes is [NO2 + OH, 90% to > 97%; BrONO2 + H2O, 10% to <3%]. The steady-state description of NOchi-HNO3 exchange reveals the significant influence of the tight correlation between the photolysis rate of HNO3 and [OH] established by in situ measurements throughout the lower stratosphere. Parametrizing this relationship, we find (I)the steady-state value of [NO2](24h-avg)/[HNO3] in the continuously sunlit, lower stratosphere is a function only of temperature acid number density, and (2) the partitioning of NO, production between HNO3 + OH and HNO3 + hv is nearly constant throughout most of the lower stratosphere. We describe a methodology (functions of latitude, day, temperature, and pressure) for accurately predicting the steady-state value of [NO2](24h-avg)/[HNO3] and the partitioning of NOchi production within these regions. The results establish a metric to compare observations of [NO2](24h-avg)/[HNO3] within the continuously sunlit region and provide a simple diagnostic for evaluating the accuracy of models that attempt to describe the coupled NOchi-HOchi photochemistry in the lower stratosphere. C1 Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Geol & Geophys, Berkeley, CA 94720 USA. CALTECH, Div Engn, Pasadena, CA 91125 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Environm Canada, Meteorol Serv Canada, Downsview, ON, Canada. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Perkins, KK (reprint author), Harvard Univ, Dept Chem & Biol Chem, 12 Oxford St, Cambridge, MA 02138 USA. RI Salawitch, Ross/B-4605-2009; Cohen, Ronald/A-8842-2011; Wennberg, Paul/A-5460-2012; Gao, Ru-Shan/H-7455-2013; Bonne, Gisele/G-3121-2013 OI Salawitch, Ross/0000-0001-8597-5832; Cohen, Ronald/0000-0001-6617-7691; NR 56 TC 20 Z9 20 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 8 PY 2001 VL 105 IS 9 BP 1521 EP 1534 DI 10.1021/jp002519n PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 407JN UT WOS:000167268600016 ER PT J AU Lanzendorf, EJ Hanisco, TF Wennberg, PO Cohen, RC Stimpfle, RM Anderson, JG Gao, RS Margitan, JJ Bui, TP AF Lanzendorf, EJ Hanisco, TF Wennberg, PO Cohen, RC Stimpfle, RM Anderson, JG Gao, RS Margitan, JJ Bui, TP TI Establishing the dependence of [HO2]/[OH]] on temperature, halogen loading, O-3, and NOx based on in situ measurements from the NASA ER-2 SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID LOWER STRATOSPHERE; INSITU MEASUREMENTS; UPPER TROPOSPHERE; 72-DEGREES-S LATITUDE; REACTIVE NITROGEN; OH; AIRCRAFT; HO2; CHEMISTRY; PHOTOCHEMISTRY AB In situ observations of OH and HO2 from the Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft (ASHOE/MAESA), Stratospheric TRacers of Atmospheric Transport (STRAT), and Polar Ozone Loss in the Arctic Region in Summer (POLARIS) NASA ER-2 field campaigns are used to examine the partitioning of HOchi in the lower stratosphere (tropopause to similar to 21 km) and upper troposphere (similar to 10 km to tropopause). These measurements span a latitude range from 70 degreesS to 90 degreesN and a variety of atmospheric conditions as a result of seasonal changes and altitude. The response of the observed [HO2]/[OH] to changes in temperature, [O-3], [CO], [NO], [CIO], and [BrO] is investigated. The measured ratio is accurately described (similar to+/-10%) by a steady-state model constrained by the measured mixing ratios of O-3, CO, NO, CIO, and BrO, where the model is valid for conditions of HOchi, cycling much faster than HOchi production and loss. The concentration of HO2 depends on [OH], which, to first order, has been observed to be a simple function of the solar zenith angle in the lower stratosphere.(1) The partitioning between OH and HO2 is controlled by the local chemistry between the HOchi radicals and O-3, CO, NO, CIO, and BrO. The response of [HOchi] to changes in [NOchi] and [O-3] is demonstrated. Further observations are necessary to illustrate the response of HOchi to changes in halogen concentrations. A quantitative understanding of [HO2]/ [OH] is important, since many of the reactions that control this ratio are directly involved in catalytic removal of O-3 in the lower stratosphere and production of O-3 in the upper troposphere. C1 Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Div Engn, Pasadena, CA 91125 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Lanzendorf, EJ (reprint author), Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. RI Cohen, Ronald/A-8842-2011; Wennberg, Paul/A-5460-2012; Gao, Ru-Shan/H-7455-2013 OI Cohen, Ronald/0000-0001-6617-7691; NR 29 TC 12 Z9 12 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 8 PY 2001 VL 105 IS 9 BP 1535 EP 1542 DI 10.1021/jp0023841 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 407JN UT WOS:000167268600017 ER PT J AU Hanisco, TF Lanzendorf, EJ Wennberg, PO Perkins, KK Stimpfle, RM Voss, PB Anderson, JG Cohen, RC Fahey, DW Gao, RS Hintsa, EJ Salawitch, RJ Margitan, JJ McElroy, CT Midwinter, C AF Hanisco, TF Lanzendorf, EJ Wennberg, PO Perkins, KK Stimpfle, RM Voss, PB Anderson, JG Cohen, RC Fahey, DW Gao, RS Hintsa, EJ Salawitch, RJ Margitan, JJ McElroy, CT Midwinter, C TI Sources, sinks, and the distribution of OH in the lower stratosphere SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID IN-SITU OBSERVATIONS; SOUTHERN-HEMISPHERE; ARCTIC REGION; OZONE LOSS; PHOTOCHEMISTRY; AIRCRAFT; SUMMER; NO2; CHLORINE; RADICALS AB Extensive measurement campaigns by the NASA ER-2 research aircraft have obtained a nearly pole-to-pole database of the species that control HOchi (OH + HO2) chemistry. The wide dynamic range of these in situ measurements provides an opportunity to demonstrate empirically the mechanisms that control the HOchi system. Measurements in the lower stratosphere show a remarkably tight correlation of OH concentration with the solar zenith angle (SZA). This correlation is nearly invariant over latitudes ranging from 70 degrees S to 90 degrees N and all seasons. An analysis of the production and loss of HOchi in terms of the rate determining steps of reaction sequences developed by Johnston and Podolske and Johnston and Kinnison is used to clarify the behavior of the system and to directly test our understanding of the system with observations. Calculations using in situ measurements show that the production rate of HOchi is proportional to O-3 and ultraviolet radiation flux. The loss rate is proportional to the concentration and the partitioning of NO, (reactive nitrogen) and the concentration of HO2. In the absence of heterogeneous reactions, the partitioning of NOgamma is controlled by O-3 and HOchi and the concentration of HO2 is controlled by NOgamma and O-3, so that the removal rate of OH is buffered against changes in the correlation of O-3 and NOgamma. The heterogeneous conversion of NO2 to HNO3 is not an important net source of HOchi because production and removal sequences are nearly balanced. Changes in NOgamma partitioning resulting from heterogeneous chemistry have a large effect on the loss rates of HOchi, but little or no impact on the measured abundance of OH. The enhanced loss rates at high NO2/HNO3 are offset in the data set examined here by enhanced production rates resulting from increased photolysis rates resulting from the decreased O-3 column above the ER-2. C1 Harvard Univ, Dept Chem, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. NOAA, Boulder, CO USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Atmospher Environm, Downsview, ON, Canada. RP Hanisco, TF (reprint author), Harvard Univ, Dept Chem, 12 Oxford St, Cambridge, MA 02138 USA. RI Salawitch, Ross/B-4605-2009; Cohen, Ronald/A-8842-2011; Wennberg, Paul/A-5460-2012; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013 OI Salawitch, Ross/0000-0001-8597-5832; Cohen, Ronald/0000-0001-6617-7691; Fahey, David/0000-0003-1720-0634 NR 25 TC 21 Z9 21 U1 0 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 8 PY 2001 VL 105 IS 9 BP 1543 EP 1553 DI 10.1021/jp002334g PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 407JN UT WOS:000167268600018 ER PT J AU Louis, F Gonzalez, CA Huie, RE Kurylo, MJ AF Louis, F Gonzalez, CA Huie, RE Kurylo, MJ TI An ab initio study of the kinetics of the reactions of halomethanes with the hydroxyl radical. 3. Kinetic parameters predictions for the potential halon replacements CH2FBr, CHFBr2, CHFClBr, CHCl2Br, and CHClBr2 SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSITION-STATE THEORY; PLESSET PERTURBATION-THEORY; COLLINEAR REACTIONS; HYDROGEN MOLECULES; SPIN PROJECTION; OH AB Ab initio PMP4(SDTQ)/6-311G(3df,2p)//MP2/6-311G(2d,2p) calculations, together with canonical transition state theory, were used in order to compute the energetics and predict the kinetics (in the temperature range 250-400 K) of the H atom abstraction reaction between the hydroxyl radical and the five halomethanes: CH2FBr, CHFBr2, CHFClBr, CHCl2Br, and CHClBr2. The procedure adopted in this study has been discussed and validated in our previous two publications (Louis, F.; Gonzalez, C. A.; Huie, R. E.; Kurylo, M. J. J. Phys. Chem. A 2000, 104, 2931. Louis, F.; Gonzalez, C. A.; Huie, R. E.; Kurylo, M. J. J. Phys. Chem. A 2000, 104, 8773.). In the present work, this computational procedure is extended to develop relations of the Evans-Polanyi type, which provide an alternate method to predict rate constants for other reactions where computational expense becomes a limiting factor. In addition, rate constants computed at 277 K were used in the estimation of the atmospheric lifetimes for the five halomethanes. The validity of these results is also discussed. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Louis, F (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Huie, Robert/A-5645-2010; Kurylo, Michael/H-2201-2012; OI Louis, Florent/0000-0002-9533-557X NR 33 TC 11 Z9 11 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 8 PY 2001 VL 105 IS 9 BP 1599 EP 1604 DI 10.1021/jp001923j PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 407JN UT WOS:000167268600025 ER PT J AU Brown, SS Burkholder, JB Talukdar, RK Ravishankara, AR AF Brown, SS Burkholder, JB Talukdar, RK Ravishankara, AR TI Reaction of hydroxyl radical with nitric acid: Insights into its mechanism SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ABSORPTION CROSS-SECTIONS; RATE COEFFICIENTS; RATE-CONSTANT; TEMPERATURE-DEPENDENCE; QUANTUM YIELDS; REACTION-RATES; OH; HNO3; KINETICS; PHOTODISSOCIATION AB The rate constant for the reaction of hydroxyl radicals with nitric acid has an unusual pressure and temperature dependence. To explore the mechanism for this reaction, we have measured rate constants for reactions of isotopically substituted species OD + DNO(3), OH + DNO(3), OD + HNO(3), and (18)OH + HNO(3) and the yield of NO(3) product. Deuterium substitution on nitric acid results in more than a 10-fold reduction in the rate constant, removes the pressure dependence (over the observed range of 20-200 Torr in He and SF(6)), and leads to a strongly curved Arrhenius temperature dependence. Deuterium substitution on hydroxyl increases the rate constant slightly but does not change the pressure dependence. There is no evidence for exchange reactions in the isotopically mixed reactions. Absorption measurements of the NO(3) product yield show that the title reaction produces nitrate radical with unit efficiency over all temperatures and pressures studied. We discuss the implications of the measured rare constants, product yields, and lack of isotopic exchange in terms of a mechanism that involves formation of a hydroxyl radical-nitric acid complex and its subsequent reaction to give NO(3) and H(2)O. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Brown, SS (reprint author), NOAA, Aeron Lab, 325 Broadway,R-AL2, Boulder, CO 80305 USA. RI TALUKDAR, RANAJIT/G-4530-2013; Burkholder, James/H-4914-2013; Brown, Steven/I-1762-2013; Ravishankara, Akkihebbal/A-2914-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 46 TC 31 Z9 31 U1 0 U2 19 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 MAR 8 PY 2001 VL 105 IS 9 BP 1605 EP 1614 DI 10.1021/jp002394m PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 407JN UT WOS:000167268600026 ER PT J AU Klemm, RB Thorn, RP Stief, LJ Buckley, TJ Johnson, RD AF Klemm, RB Thorn, RP Stief, LJ Buckley, TJ Johnson, RD TI Heat of formation of OBrO: Experimental photoionization study SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID JANAF THERMOCHEMICAL TABLES; IONIZATION-ENERGY; EFFICIENCY SPECTRUM; OZONE DEPLETION; BROMINE DIOXIDE; AB-INITIO; 298 K; RADICALS; OXIDES; IODINE AB The appearance energy of BrO+ from the dissociative ionization of OBrO was determined from the photoionization efficiency spectrum of BrO+ over the wavelength range lambda = 90-122 nm by using a discharge flow-photoionization mass spectrometer apparatus coupled to a vacuum- ultraviolet synchrotron radiation source. Bromine dioxide was generated in a flow tube reactor by first forming BrO via the reaction O(P-3) + Br-2 and then allowing the BrO to react on the cold flow tube wall. Species present in addition to OBrO were BrO, HOBr, Br2O, and residual BT2. The results are perturbed by a signal from BrO+ formed by direct photoionization of BrO and by the dissociative ionization of Br2O. It was possible to correct for these perturbations to obtain a clean appearance energy plot that yielded a threshold at lambda = 98.65 +/- 0.23 nm. This gives AE(298)(BrO+,OBrO) = 12.56(8) +/- 0.02(9) eV. Taking known thermodynamic quantities, this result yields Delta H-f(0)o(OBrO) = 173.4 +/- 4.3 kJ mol(-1) (and Delta H-f(298)o(OBrO) = 163.9 +/- 4.4 kJ mol(-1)). This is the first experimental determination of the heat of formation of OBrO, and the present result is compared with those of previous estimates and recent calculations. In addition, computations (based on results from ab initio calculations) were performed to obtain Delta H-f(0)o(OBrO) = 164 +/- 8 kJ mol(-1), which is in very good agreement with our experimental result. Also, a value for Delta H-f(0)o(OIO) of 174 +/- 25 kJ mol(-1) was estimated from a trend analysis that employed Chase's method (i.e., Delta H-at(0)o(OXO)/D-0(o)(XO)). Additionally, a comparison is made of recent photoelectron spectroscopic and photoionization mass spectrometric determinations of the ionization energies of BrO and OBrO. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Klemm, RB (reprint author), Brookhaven Natl Lab, Bldg 815,POB 5000, Upton, NY 11973 USA. NR 44 TC 13 Z9 13 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 8 PY 2001 VL 105 IS 9 BP 1638 EP 1642 DI 10.1021/jp002397z PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 407JN UT WOS:000167268600030 ER PT J AU Clark, CW AF Clark, CW TI Ugo Fano (1912-2001) - Obituary SO NATURE LA English DT Biographical-Item C1 NIST, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RP Clark, CW (reprint author), NIST, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 1 TC 2 Z9 2 U1 0 U2 2 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAR 8 PY 2001 VL 410 IS 6825 BP 164 EP 164 DI 10.1038/35065786 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 408HJ UT WOS:000167320500029 ER PT J AU Ziegler, BV Holts, DB Kennedy, B Ramon, DA Graham, JB Lai, NC AF Ziegler, BV Holts, DB Kennedy, B Ramon, DA Graham, JB Lai, NC TI Catecholamine and lactate levels in tag-release pelagic sharks. SO FASEB JOURNAL LA English DT Meeting Abstract C1 Univ San Diego, San Diego, CA 92110 USA. SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. Univ Calif San Diego, San Diego, CA 92103 USA. NR 0 TC 0 Z9 0 U1 2 U2 2 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 7 PY 2001 VL 15 IS 4 BP A414 EP A414 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 410KA UT WOS:000167438102364 ER PT J AU Hamilton, H Caballero, S Collins, AG Brownell, RL AF Hamilton, H Caballero, S Collins, AG Brownell, RL TI Evolution of river dolphins SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE Cetacea; fossil; phylogeny; Odontoceti; Miocene; epicontinental seas ID CYTOCHROME-B; PHYLOGENETIC-RELATIONSHIPS; SOUTH-AMERICA; DNA-SEQUENCES; LATE MIOCENE; CETACEANS; WHALES; RECONSTRUCTION; LINEAGES AB The world's river dolphins (Inia, Pontoporia, Lipotes and Platanista) are among the least known and most endangered of all cetaceans. The four extant genera inhabit geographically disjunct river systems and exhibit highly modified morphologies, leading many cetologists to regard river dolphins as an unnatural group. Numerous arrangements have been proposed for their phylogenetic relationships to one another and to other odontocete cetaceans. These alternative views strongly affect the biogeographical and evolutionary implications raised by the important, although limited, fossil record of river dolphins. We present a hypothesis of river dolphin relationships based on phylogenetic analysis of three mitochondrial genes for 29 cetacean species, concluding that the four genera represent three separate, ancient branches in odontocete evolution. Our molecular phylogeny corresponds well with the first fossil appearances of the primary lineages of modern odontocetes. Integrating relevant events in Tertiary palaeoceanography, we develop a scenario far river dolphin evolution during the globally high sea levels of the Middle Miocene. We suggest that ancestors of the four extant river dolphin lineages colonized the shallow epicontinental seas that inundated the Amazon, Parana, Yangtze and Indo-Gangetic river basins, subsequently remaining in these extensive waterways during their transition to freshwater with the Late Neogene trend of sea-level lowering. C1 Univ Calif Berkeley, Museum Paleontol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. Fdn Yubarta, Cali, Colombia. SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Hamilton, H (reprint author), Univ Calif Berkeley, Museum Paleontol, Berkeley, CA 94720 USA. EM heals@socrates.berkeley.edu RI Collins, Allen/A-7944-2008 OI Collins, Allen/0000-0002-3664-9691 NR 68 TC 101 Z9 115 U1 8 U2 48 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD MAR 7 PY 2001 VL 268 IS 1466 BP 549 EP 556 PG 8 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA 410GT UT WOS:000167432800014 PM 11296868 ER PT J AU Holland, M Park, J Walser, R AF Holland, M Park, J Walser, R TI Formation of pairing fields in resonantly coupled atomic and molecular Bose-Einstein condensates SO PHYSICAL REVIEW LETTERS LA English DT Article ID FESHBACH RESONANCE; SCATTERING AB We show that pair correlations may ploy an important role in the dynamical properties of a Bose-Einstein condensed gas composed of an atomic field resonantly coupled with a condensed field of molecular dimers. Specifically, pair correlations in this system can dramatically modify the coherent and incoherent transfers between the atomic and molecular fields. C1 Univ Colorado, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Holland, M (reprint author), Univ Colorado, Boulder, CO 80309 USA. NR 16 TC 117 Z9 118 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 5 PY 2001 VL 86 IS 10 BP 1915 EP 1918 DI 10.1103/PhysRevLett.86.1915 PG 4 WC Physics, Multidisciplinary SC Physics GA 407EU UT WOS:000167259900002 PM 11289819 ER PT J AU Harper, WW Nizkorodov, SA Nesbitt, DJ AF Harper, WW Nizkorodov, SA Nesbitt, DJ TI Differential scattering dynamics of F+CH4 -> HF(v,J)+CH3 via high-resolution IR laser dopplerimetry SO CHEMICAL PHYSICS LETTERS LA English DT Article ID STATE-TO-STATE; RESOLVED REACTIVE SCATTERING; CROSS-SECTIONS; SUPERSONIC JETS; ENERGY; DISTRIBUTIONS; QUANTUM; ABSORPTION; THRESHOLD; F+H-2 AB Product recoil data from F + CH4 --> HF(v,J) + CH3 reactive scattering are obtained using crossed supersonic jets and narrow band (Deltav approximate to 0.0001 cm (1)) infrared radiation laser direct absorption techniques. The high-resolution infrared radiation profiles of HF(v, J) product exhibit extensive Doppler broadening that directly reflects quantum state-resolved translational distributions in the laboratory frame under single collision conditions. Analyses of Doppler profiles yield information on state-resolved differential cross sections into the HF(v = 1) and HF(v = 2) vibrational manifolds, which both identify a propensity for forward/backward scattering (/cos(theta)/approximate to 1) over side scattering (/cos(theta)/ approximate to 0) in the center-of-mass frame. (C) 2001 Published by Elsevier Science B.V. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Nesbitt, DJ (reprint author), Univ Colorado, Dept Chem & Biochem, 325 Broadway, Boulder, CO 80309 USA. RI Nizkorodov, Sergey/I-4120-2014 OI Nizkorodov, Sergey/0000-0003-0891-0052 NR 23 TC 30 Z9 30 U1 0 U2 7 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 MAR 2 PY 2001 VL 335 IS 5-6 BP 381 EP 387 DI 10.1016/S0009-2614(01)00034-3 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 408CM UT WOS:000167309000006 ER PT J AU Cziczo, DJ Thomson, DS Murphy, DM AF Cziczo, DJ Thomson, DS Murphy, DM TI Ablation, flux, and atmospheric implications of meteors inferred from stratospheric aerosol SO SCIENCE LA English DT Article ID ACCRETION RATE; DIFFERENTIAL ABLATION; COSMIC SPHERULES; DUST; ABUNDANCES; COLLECTION; PARTICLES; ELEMENTS; SOLAR; OZONE AB Single-particle analyses of stratospheric aerosol show that about half of the particles contain 0.5 to 1.0 weight percent meteoritic iron by mass, requiring a total extraterrestrial influx of 8 to 38 gigagrams per year. The sodium/iron ratio in these stratospheric particles is higher and the magnesium/iron and calcium/iron ratios are Lower than in chondritic meteorites, implying that the fraction of material that is ablated must lie at the Low end of previous estimates and that the extraterrestrial component that resides in the mesosphere and stratosphere is not of chondritic composition. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Murphy, DM (reprint author), NOAA, Aeron Lab, Boulder, CO 80305 USA. RI Murphy, Daniel/J-4357-2012 OI Murphy, Daniel/0000-0002-8091-7235 NR 33 TC 86 Z9 88 U1 3 U2 14 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 MAR 2 PY 2001 VL 291 IS 5509 BP 1772 EP 1775 DI 10.1126/science.1057737 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 408HK UT WOS:000167320600055 PM 11230690 ER PT J AU Rasberry, SD AF Rasberry, SD TI Certified reference materials in analytical chemistry - A century of NIST contribution SO ACCREDITATION AND QUALITY ASSURANCE LA English DT Review AB Over the course of its first 100 years, the National Institute of Standards and Technology (NIST) has made numerous contributions to advancing the science and practice of analytical chemistry. Contributions to fundamental constants and reference data, such as determination of the Faraday, Avagadro's number, and atomic masses, began at almost the beginning of the new institution when it was formed in 1901. Instrumentation development, improvement, and reproducible methods for its use have also been an important part of the NIST effort. This paper will describe what may be the organization's most important and certainly its most unique contribution; namely, certified reference materials. Ultimately these certified reference materials would become known at NIST as standard reference materials (SRMs). It is a contribution that now has been mirrored around the world with reference materials being certified in at least 25 countries and routinely applied in more than twice that number. The result has been more accurate analyses of materials that impact our safety, health, and well-being. C1 Natl Inst Stand & Technol, Measurement Serv, Gaithersburg, MD 20878 USA. RP Rasberry, SD (reprint author), Natl Inst Stand & Technol, Measurement Serv, 31 Longmeadow Dr, Gaithersburg, MD 20878 USA. NR 2 TC 3 Z9 3 U1 0 U2 4 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 MAR PY 2001 VL 6 IS 3 BP 95 EP 99 DI 10.1007/PL00010448 PG 5 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA 402PN UT WOS:000166997500002 ER PT J AU Belanger, B AF Belanger, B TI The measurement assurance concept in calibration and traceability at NBS/NIST SO ACCREDITATION AND QUALITY ASSURANCE LA English DT Article DE traceability; measurement assurance; calibration; statistics AB During the last quarter of the twentieth century, The United States National Bureau of Standards (NBS), later the National Institute of Standards and Technology (NIST), introduced a measurement quality control concept called "measurement assurance," and developed measurement assurance programs, or MAPs, for high-level calibration processes. The measurement assurance approach has, over time, become increasingly popular in the metrology community, and in recent years has become well accepted both inside and, to some extent, outside the United States as a rigorous way to ensure the quality of calibrations. The concept has also found application in defining traceability to national standards. This paper traces the history of the measurement assurance concept. C1 Natl Inst Stand & Technol, Visiting Comm Adv Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Visiting Comm Adv Technol, Gaithersburg, MD 20899 USA. EM bcbelanger@aol.com NR 13 TC 0 Z9 0 U1 1 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0949-1775 EI 1432-0517 J9 ACCREDIT QUAL ASSUR JI Accredit. Qual. Assur. PD MAR PY 2001 VL 6 IS 3 BP 100 EP 102 DI 10.1007/PL00010443 PG 3 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA 402PN UT WOS:000166997500003 ER PT J AU Peiser, HS AF Peiser, HS TI Measurement science at the national bureau of standards SO ACCREDITATION AND QUALITY ASSURANCE LA English DT Letter C1 US Natl Bur Stand, Gaithersburg, MD 20877 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 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 MAR PY 2001 VL 6 IS 3 BP 111 EP 112 DI 10.1007/PL00010446 PG 2 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA 402PN UT WOS:000166997500006 ER PT J AU Baldocchi, D Falge, E Wilson, K AF Baldocchi, D Falge, E Wilson, K TI A spectral analysis of biosphere-atmosphere trace gas flux densities and meteorological variables across hour to multi-year time scales SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE Fourier analysis; evaporation; carbon dioxide exchange; micrometeorology; biometeorology; energy exchange; biosphere-atmosphere interactions ID CARBON-DIOXIDE EXCHANGE; WATER-VAPOR EXCHANGE; DECIDUOUS FOREST; TERRESTRIAL ECOSYSTEMS; CO2; CLIMATE; TEMPERATURE; VEGETATION; DROUGHT; SURFACE AB The advent of long-term studies on CO2 and water vapor exchange provides us with new information on how the atmosphere and biosphere interact. Conventional time series analysis suggests that temporal fluctuations of weather variables and mass and energy flux densities occur on numerous time scales. The time scales of variance that are associated with annual time series of meteorological variables, scalar Aux densities and their covariance with one another, however, remain unquantified. We applied Fourier analysis to time series (4 years in duration) of photon flux density, air temperature, wind speed, pressure and the flux densities of CO2 and water vapor. At the daily time scale, strong spectral peaks occurred in the meteorological and flux density records at periods of 12 and 24h, due to the daily rising and setting of the sun. At the synoptic time scale (3-7 days) the periodic passage of weather fronts alter available sunlight and temperature. In turn, variations in these state variables affect carbon assimilation, respiration and transpiration. At the seasonal and semi-annual time scales, a broad spectral peak occurs due to seasonal changes in weather and plant functionality and phenology. In general, 21% of the variance of CO2 exchange is associated with the annual cycle, 43% of the variance is associated with the diurnal cycle and 9% is associated with the semi-annual time scale. A pronounced spectral gap was associated with periods 3-4 weeks long. Interactions between CO2 flux density (F-c) and sunlight, air temperature and latent heat flux density were quantified using co-spectral, coherence and phase angle analyzes. Coherent and in-phase spectral peaks occur between CO2 exchange rates and water vapor exchange on annual, seasonal and daily time scales. A 180 degrees phase shift occurs between F-c and photon Aux density (Q(p)) On seasonal and daily time scales because the temporal course of sunlight corresponds with the withdrawal of CO2 from the atmosphere, a flux that possesses a negative sign. Covariations between F-c and T-air experience a 180 degrees phase shift with one another at the seasonal time scale because rising temperatures are associated with more carbon uptake. At daily time scales the phase angle between F-c and T-air is on the order of 130 degrees. This phase lag can be explained by the strong dependence of canopy photosynthesis on available light and the 2-3 h lags, which occur between the daily course of sunlight and air temperature. Spectral analysis was used to investigate the performance of a biophysical model (CANOAK) across a spectrum of time scales. By varying meteorology, leaf area index and photosynthetic capacity, the model was able to replicate most of the spectral gaps and peaks that were associated with CO2 exchange, when soil moisture was ample. Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Dept Environm Sci, Ecosyst Sci Div, Berkeley, CA 94720 USA. Univ Bayreuth, D-95440 Bayreuth, Germany. NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. RP Baldocchi, D (reprint author), Univ Calif Berkeley, Dept Environm Sci, Ecosyst Sci Div, 151 Hilgard Hall, Berkeley, CA 94720 USA. RI Baldocchi, Dennis/A-1625-2009 OI Baldocchi, Dennis/0000-0003-3496-4919 NR 67 TC 104 Z9 117 U1 6 U2 38 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD MAR 1 PY 2001 VL 107 IS 1 BP 1 EP 27 DI 10.1016/S0168-1923(00)00228-8 PG 27 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 406AE UT WOS:000167192100001 ER PT J AU Falge, E Baldocchi, D Olson, R Anthoni, P Aubinet, M Bernhofer, C Burba, G Ceulemans, R Clement, R Dolman, H Granier, A Gross, P Grunwald, T Hollinger, D Jensen, NO Katul, G Keronen, P Kowalski, A Lai, CT Law, BE Meyers, T Moncrieff, H Moors, E Munger, JW Pilegaard, K Rannik, U Rebmann, C Suyker, A Tenhunen, J Tu, K Verma, S Vesala, T Wilson, K Wofsy, S AF Falge, E Baldocchi, D Olson, R Anthoni, P Aubinet, M Bernhofer, C Burba, G Ceulemans, R Clement, R Dolman, H Granier, A Gross, P Grunwald, T Hollinger, D Jensen, NO Katul, G Keronen, P Kowalski, A Lai, CT Law, BE Meyers, T Moncrieff, H Moors, E Munger, JW Pilegaard, K Rannik, U Rebmann, C Suyker, A Tenhunen, J Tu, K Verma, S Vesala, T Wilson, K Wofsy, S TI Gap filling strategies for defensible annual sums of net ecosystem exchange SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE FLUXNET; EUROFLUX; AmeriFlux; eddy covariance; F-NEE; data filling; interpolation techniques ID WATER-VAPOR EXCHANGE; PONDEROSA PINE ECOSYSTEM; MODELING CARBON-DIOXIDE; DECIDUOUS FOREST; SOIL RESPIRATION; TALL VEGETATION; BEECH FOREST; FLUXES; VARIABILITY; ATMOSPHERE AB Heightened awareness of global change issues within both science and political communities has increased interest in using the global network of eddy covariance flux towers to more fully understand the impacts of natural and anthropogenic phenomena on the global carbon balance. Comparisons of net ecosystem exchange (F-NEE) responses are being made among biome types, phenology patterns, and stress conditions. The comparisons are usually performed on annual sums of F-NEE; however, the average data coverage during a year is only 65%. Therefore, robust and consistent gap filling methods are required. We review several methods of gap filling and apply them to data sets available from the EUROFLUX and AmeriFlux databases. The methods are based on mean diurnal variation (MDV), look-up tables LookUp, and nonlinear regressions (Regr.), and the impact of different gap filling methods on the annual sum of FNEE is investigated. The difference between annual F-NEE filled by MDV compared to F-NEE filled by Regr. ranged from -45 to +200 g C m(-2) per year (MDV-Regr.). Comparing LookUp and Regr. methods resulted in a difference (LookUp-Regr.) ranging from -30 to +150g Cm-2 per year. We also investigated the impact of replacing measurements at night, when turbulent mixing is insufficient. The nighttime correction for low friction velocities (u(*)) shifted annual F-NEE on average by +77 g C m(-2) per year, but in certain cases as much as +185 g C m-2 per year. Our results emphasize the need to standardize gap filling-methods for improving the comparability of flux data products from regional and global flux networks. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, SPM, Berkeley, CA 94704 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN USA. Oregon State Univ, Corvallis, OR 97331 USA. Fac Sci Agron Gembloux, Unite Phys, B-5030 Gembloux, Belgium. Tech Univ Dresden, IHM Meteorol, D-01737 Tharandt, Germany. Univ Nebraska, Sch Nat Resource Sci, Lincoln, NE 68583 USA. Univ Instelling Antwerp, Lab Plant Ecol, Dept Biol, B-2610 Wilrijk, Belgium. Univ Edinburgh, Inst Ecol & Resource Management, Edinburgh EH9 3JU, Midlothian, Scotland. Alterra, NL-6700 AA Wageningen, Netherlands. INRA, Unite Ecophysiol Forestiere, F-54280 Seichamps, France. USDA, Forest Serv, Durham, NH 03824 USA. Riso Natl Lab, Plant Biol & Biogeochem Dept, DK-4000 Roskilde, Denmark. Duke Univ, Sch Environm, Durham, NC 27708 USA. Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. NOAA, ATDD, Oak Ridge, TN 37831 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Max Planck Inst Biogeochem, D-07701 Jena, Germany. Univ Bayreuth, D-95440 Bayreuth, Germany. Univ New Hampshire, Dept Nat Resources, Durham, NH 03824 USA. RP Falge, E (reprint author), Univ Calif Berkeley, SPM, Berkeley, CA 94704 USA. RI Pilegaard, Kim/I-7137-2013; Meyers, Tilden/C-6633-2016; Ceulemans, Reinhart/F-2109-2016; Munger, J/H-4502-2013; Burba, George/G-9991-2014; Vesala, Timo/C-3795-2017; Katul, Gabriel/A-7210-2008; Kowalski, Andrew/A-7515-2008; Baldocchi, Dennis/A-1625-2009; Hollinger, David/G-7185-2012; Moors, Eddy/J-5165-2012 OI Dolman, A.J./0000-0003-0099-0457; Pilegaard, Kim/0000-0002-5169-5717; Munger, J/0000-0002-1042-8452; Burba, George/0000-0003-2095-0057; Vesala, Timo/0000-0002-4852-7464; Law, Beverly/0000-0002-1605-1203; Katul, Gabriel/0000-0001-9768-3693; Kowalski, Andrew/0000-0001-9777-9708; Baldocchi, Dennis/0000-0003-3496-4919; Moors, Eddy/0000-0003-2309-2887 NR 49 TC 881 Z9 1011 U1 17 U2 205 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD MAR 1 PY 2001 VL 107 IS 1 BP 43 EP 69 DI 10.1016/S0168-1923(00)00225-2 PG 27 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 406AE UT WOS:000167192100003 ER PT J AU Falge, E Baldocchi, D Olson, R Anthoni, P Aubinet, M Bernhofer, C Burba, G Ceulemans, G Clement, R Dolman, H Granier, A Gross, P Grunwald, T Hollinger, D Jensen, NO Katul, G Keronen, P Kowalski, A Lai, CT Law, BE Meyers, T Moncrieff, J Moors, E Munger, JW Pilegaard, K Rannik, U Rebmann, C Suyker, A Tenhunen, J Tu, K Verma, S Vesala, T Wilson, K Wofsy, S AF Falge, E Baldocchi, D Olson, R Anthoni, P Aubinet, M Bernhofer, C Burba, G Ceulemans, G Clement, R Dolman, H Granier, A Gross, P Grunwald, T Hollinger, D Jensen, NO Katul, G Keronen, P Kowalski, A Lai, CT Law, BE Meyers, T Moncrieff, J Moors, E Munger, JW Pilegaard, K Rannik, U Rebmann, C Suyker, A Tenhunen, J Tu, K Verma, S Vesala, T Wilson, K Wofsy, S TI Gap filling strategies for long term energy flux data sets SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE FLUXNET; EUROFLUX; AmeriFlux; eddy covariance; latent heat; sensible heat; data filling; interpolation techniques ID EDDY-COVARIANCE; CARBON; EXCHANGE; FOREST AB At present a network of over 100 field sites are measuring carbon dioxide, water vapor and sensible heat fluxes between the biosphere and atmosphere, on a nearly continuous basis. Gaps in the long term measurements of evaporation and sensible heat flux must be filled before these data can be used for hydrological and meteorological applications. We adapted methods of gap filling for NEE (net ecosystem exchange of carbon) to energy fluxes and applied them to data sets available from the EUROFLUX and AmeriFlux eddy covariance databases. The average data coverage for the sites selected was 69% and 75% for latent heat (lambdaE) and sensible heat (H). The methods were based on mean diurnal variations (half-hourly binned means of fluxes based on previous and subsequent days, MDV) and look-up tables for fluxes during assorted meteorological conditions (LookUp), and the impact of different gap filling methods on the annual sum of lambdaE and H is investigated. The difference between annual lambdaE filled by MDV and lambdaE filled by LookUp ranged from -120 to 210 MJ m(-2) per year, i.e. -48 to +86 mm per year, or -13 to +39% of the annual sum. For annual sums of H differences between - 140 and +140 MJ m(-2) per year or -12 to +19% of the annual sum were found. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, ESPM, Berkeley, CA 94704 USA. Univ New Hampshire, Dept Nat Resources, Durham, NH 03824 USA. Univ Bayreuth, D-95440 Bayreuth, Germany. Max Planck Inst Biogeochem, D-07701 Jena, Germany. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. NOAA, ATDD, Oak Ridge, TN 37831 USA. Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. Duke Univ, Sch Environm, Durham, NC 27708 USA. Riso Natl Lab, Platn Biol & Biogeochem Dept, DK-4000 Roskilde, Denmark. US Forest Serv, USDA, Durham, NH 03824 USA. INRA, Unite Ecophysiol Forestiere, F-54280 Seichamps, France. Alterra, NL-6700 AA Wageningen, Netherlands. Univ Edinburgh, Inst Ecol & Resource Management, Edinburgh EH9 3JU, Midlothian, Scotland. Univ Instelling Antwerp, Dept Biol, Plant Biol Lab, B-2610 Wilrijk, Belgium. Univ Nebraska, Sch Nat Resouce Sci, Lincoln, NE 68583 USA. Tech Univ Dresden, IHM Meteorol, D-01737 Tharandt, Germany. Fac Sci Agron Gembloux, Unite Phys, B-5030 Gembloux, Belgium. Oregon State Univ, Corvallis, OR 97331 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Falge, E (reprint author), Univ Calif Berkeley, ESPM, Berkeley, CA 94704 USA. RI Katul, Gabriel/A-7210-2008; Kowalski, Andrew/A-7515-2008; Baldocchi, Dennis/A-1625-2009; Hollinger, David/G-7185-2012; Moors, Eddy/J-5165-2012; Pilegaard, Kim/I-7137-2013; Meyers, Tilden/C-6633-2016; Munger, J/H-4502-2013; Burba, George/G-9991-2014; Vesala, Timo/C-3795-2017; OI Katul, Gabriel/0000-0001-9768-3693; Kowalski, Andrew/0000-0001-9777-9708; Baldocchi, Dennis/0000-0003-3496-4919; Moors, Eddy/0000-0003-2309-2887; Pilegaard, Kim/0000-0002-5169-5717; Munger, J/0000-0002-1042-8452; Burba, George/0000-0003-2095-0057; Vesala, Timo/0000-0002-4852-7464; Law, Beverly/0000-0002-1605-1203 NR 12 TC 261 Z9 317 U1 4 U2 77 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD MAR 1 PY 2001 VL 107 IS 1 BP 71 EP 77 DI 10.1016/S0168-1923(00)00235-5 PG 7 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 406AE UT WOS:000167192100004 ER PT J AU Dols, WS AF Dols, WS TI A tool for modeling airflow & contaminant transport SO ASHRAE JOURNAL LA English DT Article C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Indoor Air Qual & Ventilat Grp, Gaithersburg, MD 20899 USA. RP Dols, WS (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Indoor Air Qual & Ventilat Grp, Gaithersburg, MD 20899 USA. NR 18 TC 14 Z9 14 U1 0 U2 4 PU AMER SOC HEATING REFRIGERATING AIR-CONDITIONING ENG, INC, PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA SN 0001-2491 J9 ASHRAE J JI ASHRAE J. PD MAR PY 2001 VL 43 IS 3 BP 35 EP + PG 7 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 411WX UT WOS:000167523400020 ER PT J AU Wilson, KB Meyers, TP AF Wilson, KB Meyers, TP TI The spatial variability of energy and carbon dioxide fluxes at the floor of a deciduous forest SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE ameriflux; carbon flux; deciduous forest; eddy covariance; soil respiration; spatial variability ID WATER-VAPOR EXCHANGE; EDDY FLUXES; PINE FOREST; CO2; ATMOSPHERE; CANOPIES; FOOTPRINTS; VEGETATION; PATTERNS; EFFLUX AB Fluxes of carbon dioxide, water and sensible heat were measured using three different eddy covariance systems above the forest floor of a closed deciduous forest (leaf area index approximate to 6). The primary objective was to examine the representativeness of a single eddy covariance system in estimating soil respiration for time scales ranging from one-half hour to more than one week. Experiments were conducted in which the eddy covariance sensors were in one of three configurations: i) collocated, ii) separated horizontally or iii) separated vertically. A measure of the variation between the three systems (CV',related to the coefficient of variation) for half-hour carbon dioxide fluxes was 0.14 (collocated systems), 0.34 (vertically separated systems at 1, 2 and 4 m above the surface), and 0.57 (systems horizontally separated by 30 m). A similar variation was found for other scalar fluxes (sensible and latent heat). Variability between systems decreased as the number of half-hour sampling periods used to obtain mean fluxes was increased. After forty-eight hours (means from ninety-six half-hour samples), CV' values for carbon dioxide fluxes were 0.07, 0.09 and 0.16 in the collocated, vertically separated and horizontally separated experiments, respectively. The time dependence of variability has implications on the appropriateness of using short-term measurements in modelling validation studies. There are also implications concerning the appropriate number of half-hour samples necessary to obtain reliable causal relationships between flux data and environmental parameters. Based on the longer-term measurements, we also discuss the representativeness of a single eddy covariance system in long-term monitoring of soil respiration and evaporation beneath forest canopies using the eddy covariance method. C1 NOAA, Air Resources Lab, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. RP Wilson, KB (reprint author), NOAA, Air Resources Lab, Atmospher Turbulence & Diffus Div, POB 2456, Oak Ridge, TN 37831 USA. RI Meyers, Tilden/C-6633-2016 NR 53 TC 42 Z9 46 U1 0 U2 9 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD MAR PY 2001 VL 98 IS 3 BP 443 EP 473 DI 10.1023/A:1018779506973 PG 31 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 393ZC UT WOS:000166498700004 ER PT J AU Lozano, SJ Scharold, JV Nalepa, TF AF Lozano, SJ Scharold, JV Nalepa, TF TI Recent declines in benthic macroinvertebrate densities in Lake Ontario SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID ZEBRA MUSSELS; GREAT-LAKES; DREISSENA; COMMUNITIES; INVASION; MICHIGAN; BAY; COLONIZATION; POPULATIONS; ERIE AB Surveys of benthic macroinvertebrates conducted in Lake Ontario during 1994 and 1997 revealed recent declines in populations of three major taxonomic groups: Oligochaeta, Sphaeriidae, and Diporeia spp. (Amphipoda), with the most drastic reductions occurring in the latter. Results from sediment measurements were used to classify deepwater sediments into three habitat zones. Densities of all three taxa declined in the shallowest (12-88 m) of the sediment zones between 1994 and 1997; the greatest changes in density were observed for Diporeia, which declined from 3011 to 145 individuals.m(2), and for total benthic macroinvertebrates, which declined from 5831 to 1376 individuals m(2). Mean densities of Dreissena spp. in 1997 were highest in the shallowest zone, and the areas of greatest densities corresponded to areas of largest reductions in Diporeia populations. We believe that dreissenids are competing with Diporeia by intercepting the supply of fresh algae essential for Diporeia survival. A decline in macroinvertebrate densities, especially populations of an important food item such as Diporeia, in Lake Ontario sediments at depths of 12-88 m may have a detrimental impact on the benthic food web. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. US EPA, Mid Continent Ecol Div, Duluth, MN 55804 USA. RP Lozano, SJ (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 36 TC 86 Z9 90 U1 1 U2 10 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 MAR PY 2001 VL 58 IS 3 BP 518 EP 529 DI 10.1139/cjfas-58-3-518 PG 12 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 409EK UT WOS:000167371400008 ER PT J AU Vogel, GL Zhang, Z Chow, LC Schumacher, GE AF Vogel, GL Zhang, Z Chow, LC Schumacher, GE TI Effect of a water rinse on 'labile' fluoride and ether ions in plaque and saliva before and after conventional and experimental fluoride rinses SO CARIES RESEARCH LA English DT Article DE fluoride; labile ions; plaque; saliva ID CONTAINING CHEWING GUM; HUMAN DENTAL PLAQUE; SUCROSE CHALLENGE; 2-SOLUTION RINSE; CARIES-FREE; FLUID; CALCIUM; NAF; PHOSPHATE; PH AB Labile reservoirs are important in maintaining ion concentrations in oral fluids, especially after a fluoride dentifrice application, where a persistent increase in fluid fluoride can mitigate or reverse caries progression. In this study, the effect of experimental and conventional fluoride rinses on the in vitro and in vivo water-induced release of fluoride, calcium, phosphate, acetate and hydrogen ions from oral reservoirs was examined. At the start of each experiment, 13 subjects rinsed either with a conventional 228-ppm fluoride NaF rinse, a 228-ppm fluoride controlled-release rinse (CR rinse) or received no rinse. Sixty minutes later upper and Tower molar plaque samples and 1-min saliva samples were collected. The subjects then rinsed with deionized water for 1 min, and 7 min later, a second set of samples was collected (in vivo study). Plaque fluid and clarified saliva were then recovered from samples by centrifugation, and the remaining plaque mass was sequentially extracted with water and acid to measure the water-extracted and total whole-plaque fluoride (in vitro study). All the samples were analyzed using microtechniques for pH, free calcium, phosphate, organic acids (plaque fluid) and fluoride (plaque fluid, centrifuged saliva and plaque extracts). Results showed that in vivo water rinsing decreased acetate and phosphate in plaque fluid, and fluoride in plaque fluid and saliva, but had no effect on plaque fluid pH. In vivo water rinsing, however, increased plaque fluid free calcium, apparently due to water-induced loss of calcium-binding ions. Water- or fluoride-rinse-induced changes in plaque fluid concentration were greater at the lower molar site, suggesting that rinse pooling may influence ion distribution. Before the water rinse, plaque fluid, saliva and whole-plaque total fluoride values were 1.7, 2 and 4 times higher after the CR rinse compared to the NaF rinse. Furthermore, the CR rinse deposited approximately 11 times more water-extracted fluoride compared to the NaF rinse, suggesting a 'more efficient' precipitation of 'labile' or 'loosely bound fluoride'. The results presented here, and in previous studies, suggest the possibility of formulating effective fluoride dentifrices with a lower fluoride content than is currently in use. Copyright (C) 2001 S. Karger AG. Basel. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. Pfizer, Morris Plains, NJ USA. RP Vogel, GL (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Room A153,Bldg 224, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [DE10840, DE05354] NR 36 TC 19 Z9 19 U1 0 U2 0 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 0008-6568 J9 CARIES RES JI Caries Res. PD MAR-APR PY 2001 VL 35 IS 2 BP 116 EP 124 DI 10.1159/000047442 PG 9 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 415DY UT WOS:000167706600006 PM 11275671 ER PT J AU Bentz, DP Conway, JT AF Bentz, DP Conway, JT TI Computer modeling of the replacement of "coarse" cement particles by inert fillers in low w/c ratio concretes - Hydration and strength SO CEMENT AND CONCRETE RESEARCH LA English DT Article DE blended cements; compressive strength; hydration; modeling; particle size distribution ID PERFORMANCE AB In concretes with water-to-cement (w/c) ratios below about 0.38, a portion of the cement particles will always remain unhydrated due to space limitations within the material. Thus, in many of the high-performance concretes currently being produced, cement clinker is in effect being wasted. This communication examines the possibility of replacing the coarser fraction of a cement powder by an inert filler, to conserve cement without sacrificing material performance. Using the NIST CEMHYD3D cement hydration model, it is demonstrated that for "initial" w/c ratios of 0.25 and 0.30, a portion of the coarser cement particles can be replaced by inert fillers with little projected loss in compressive strength development. Of course, the optimal replacement fraction depends on the initial w/c ratio, suggesting that blended portland/inert filler cements need to be produced with the end concrete mixture proportions in mind. This further implies that a cement/inert mixture of specific proportions will only perform optimally in a limited range of concrete mixture proportions. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Holnam Inc, Dundee, MI 48131 USA. RP Bentz, DP (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, 100 Bur Dr,Stop 8621, Gaithersburg, MD 20899 USA. RI Chen, Wei/A-5694-2010 NR 9 TC 28 Z9 30 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD MAR PY 2001 VL 31 IS 3 BP 503 EP 506 DI 10.1016/S0008-8846(01)00456-2 PG 4 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 421UT UT WOS:000168082500023 ER PT J AU Sterling, DG AF Sterling, DG TI Chaotic synchronization of coupled ergodic maps SO CHAOS LA English DT Article ID COMPLEX SPREADING SEQUENCES; ASYNCHRONOUS DS-CDMA; SECURE COMMUNICATIONS; SYSTEMS; UNMASKING; ATTRACTORS; SIGNAL; SCHEME AB With few exceptions, studies of chaotic synchronization have focused on dissipative chaos. Though less well known, chaotic systems that lack dissipation may also synchronize. Motivated by an application in communication systems, we couple a family of ergodic maps on the N-torus and study the global stability of the synchronous state. While most trajectories synchronize at some time, there is a measure zero set that never synchronizes. We give explicit examples of these asynchronous orbits in dimensions two and four. On more typical trajectories, the synchronization error reaches arbitrarily small values and, in practice, converges. In dimension two we derive bounds on the average synchronization time for trajectories resulting from randomly chosen initial conditions. Numerical experiments suggest similar bounds exist in higher dimensions as well. Adding noise to the coupling signal destroys the invariance of the synchronous state and causes typical trajectories to desynchronize. We propose a modification of the standard coupling scheme that corrects this problem resulting in robust synchronization in the presence of noise. C1 Natl Inst Stand & Technol, Div Math & Computat Sci, Boulder, CO 80303 USA. RP Natl Inst Stand & Technol, Div Math & Computat Sci, Boulder, CO 80303 USA. EM sterling@boulder.nist.gov NR 40 TC 6 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1054-1500 EI 1089-7682 J9 CHAOS JI Chaos PD MAR PY 2001 VL 11 IS 1 BP 29 EP 46 DI 10.1063/1.1350407 PG 18 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 407ZJ UT WOS:000167301400003 ER PT J AU Thomas, JB Kline, MC Gill, LM Yen, JH Duewer, DL Sniegoski, LT Sharpless, KE AF Thomas, JB Kline, MC Gill, LM Yen, JH Duewer, DL Sniegoski, LT Sharpless, KE TI Preparation and value assignment of standard reference material 968c fat-soluble vitamins, carotenoids, and cholesterol in human serum SO CLINICA CHIMICA ACTA LA English DT Article DE standard reference material; fat-soluble vitamins; carotenoids; lyophilized human serum; cholesterol; value assignment ID ALPHA-TOCOPHEROL; BETA-CAROTENE; QUANTITATIVE-DETERMINATION; LIQUID-CHROMATOGRAPHY; DEFINITIVE METHOD; RETINOL; PLASMA; STABILITY; STORAGE; ISOMERS AB Standard Reference Material 968c Fat-Soluble Vitamins, Carotenoids, and Cholesterol in Human Serum provides certified Values for retinal, delta-. gamma-, and alpha -tocopherol, trans- and total p-carotene, and cholesterol in human serum. Values are also reported for 16 additional compounds including lutein, zeaxanthin, alpha- and beta -cryptoxanthin, lycopene, cu-carotene, retinyl palmitate, and 25-hydroxyvitamin D. The certified values for the fat-soluble vitamins and carotenoids in SRM 968c were based on the agreement of results from the means of at least two liquid chromatographic methods used at the National Institute of Standards and Technology (NIST) and from the medians from an interlaboratory comparison study among institutions that participate in the NIST Micronutrients Measurement Quality Assurance Program. The assigned values for cholesterol in the SRM are the means of results obtained using the NIST definitive method, gas chromatography-isotope dilution mass spectrometry. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Thomas, JB (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8392, Gaithersburg, MD 20899 USA. RI Duewer, David/B-7410-2008; OI Sharpless, Katherine/0000-0001-6569-198X NR 34 TC 15 Z9 15 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-8981 J9 CLIN CHIM ACTA JI Clin. Chim. Acta PD MAR PY 2001 VL 305 IS 1-2 BP 141 EP 155 PG 15 WC Medical Laboratory Technology SC Medical Laboratory Technology GA 419TT UT WOS:000167965300017 ER PT J AU Christenson, RH Duh, SH Apple, FS Bodor, GS Bunk, DM Dalluge, J Panteghini, M Potter, JD Welch, MJ Wu, AHB Kahn, SE AF Christenson, RH Duh, SH Apple, FS Bodor, GS Bunk, DM Dalluge, J Panteghini, M Potter, JD Welch, MJ Wu, AHB Kahn, SE TI Standardization of cardiac troponin I assays: Round robin of ten candidate reference materials SO CLINICAL CHEMISTRY LA English DT Article ID ACUTE MYOCARDIAL-INFARCTION; ACUTE CORONARY SYNDROMES; UNSTABLE ANGINA; SERUM; STRATIFICATION; DIAGNOSIS; MARKERS; BENEFIT AB Background: Cardiac troponin I (cTnI) results vary 100-fold among assays. As a step toward standardization, we examined the performance of 10 candidate reference materials (cRMs) in dilution studies with 13 cTnI measurement systems. Methods: Solutions of 10 cTnI cRMs, each characterized by NIST, were shipped to the manufacturers of 13 cTnI measurement systems. Manufacturers used their respective diluents to prepare each cRM in cTnI concentrations of 1, 10, 25, and 50 mug/L,. For the purpose of ranking the cRMs, the deviation of each cTnI measurement from the expected response was assessed after normalization with the 10 mug/L cTnI solution. Normalized deviations were examined in five formats. Parameters from linear regression analysis of the measured cTnI vs expected values were also used to rank performance of the cRMs. Results: The three cRMs demonstrating the best overall rankings were complexes of troponins C, I, and T. The matrices for these three cRMs values differed; one was reconstituted directly from the lyophilized form submitted by the supplier; one was submitted in liquid form, lyophilized at NIST, and subsequently reconstituted; and the third was evaluated in the liquid form received from the supplier. The cRM demonstrating the fourth best performance was a binary complex of troponins C and I supplied in lyophilized form and reconstituted before distribution. Conclusions: The cRMs demonstrating the best performance characteristics in 13 cTnI analytical systems will be included in subsequent activities of the cTnI Standardization Committee of the AACC, (C) 2001 American Association for Clinical Chemistry. C1 Univ Maryland, Sch Med, Dept Pathobiol, Baltimore, MD 21201 USA. Hennepin Cty Med Ctr, Dept Lab Med & Pathol, Minneapolis, MN 55415 USA. Univ Minnesota, Sch Med, Minneapolis, MN 55415 USA. Denver Hlth Med Ctr, Denver, CO 80204 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. Azienda Osped Spedali Civili, Clin Chem Lab, I-25125 Brescia, Italy. Univ Miami, Sch Med, Dept Pharmacol, Miami, FL 33101 USA. Hartford Hosp, Dept Pathol & Lab Med, Hartford, CT 06102 USA. Loyola Univ, Med Ctr, Dept Pathol, Maywood, IL 60153 USA. Loyola Univ, Med Ctr, Dept Cell Biol, Maywood, IL 60153 USA. Loyola Univ, Med Ctr, Dept Neurobiol, Maywood, IL 60153 USA. Loyola Univ, Med Ctr, Dept Anat, Maywood, IL 60153 USA. RP Christenson, RH (reprint author), Univ Maryland, Sch Med, Dept Pathobiol, 22 S Greene St, Baltimore, MD 21201 USA. NR 15 TC 73 Z9 87 U1 0 U2 2 PU AMER ASSOC CLINICAL CHEMISTRY PI WASHINGTON PA 2101 L STREET NW, SUITE 202, WASHINGTON, DC 20037-1526 USA SN 0009-9147 J9 CLIN CHEM JI Clin. Chem. PD MAR PY 2001 VL 47 IS 3 BP 431 EP 437 PG 7 WC Medical Laboratory Technology SC Medical Laboratory Technology GA 408VG UT WOS:000167347700009 PM 11238293 ER PT J AU Boisvert, RF Moreira, J Philippsen, M Pozo, R AF Boisvert, RF Moreira, J Philippsen, M Pozo, R TI Java and numerical computing SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article ID PERFORMANCE AB Java represents both a challenge and an opportunity to practitioners of numerical computing. This article analyzes the current state of Java in numerical computing and identifies some directions for the realization of its full potential. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. IBM Corp, TJ Watson Res Ctr, Armonk, NY 10504 USA. Univ Karlsruhe, Karlsruhe, Germany. RP Boisvert, RF (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. OI Boisvert, Ronald/0000-0002-4445-1044 NR 9 TC 21 Z9 22 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD MAR-APR PY 2001 VL 3 IS 2 BP 18 EP 24 DI 10.1109/5992.908997 PG 7 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 405BA UT WOS:000167136300006 ER PT J AU Beichl, I Sullivan, F AF Beichl, I Sullivan, F TI In order to form a more perfect UNION SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Editorial Material C1 NIST, Informat Lab, Gaithersburg, MD 20899 USA. IDA Ctr Comp Sci, Bowie, MD 20715 USA. RP Beichl, I (reprint author), NIST, Informat Lab, Gaithersburg, MD 20899 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD MAR-APR PY 2001 VL 3 IS 2 BP 60 EP 64 PG 5 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 405BA UT WOS:000167136300013 ER PT J AU Grady, JM Coykendall, DK Collette, BB Quattro, JM AF Grady, James M. Coykendall, D. K. Collette, B. B. Quattro, J. M. TI Taxonomic diversity, origin, and conservation status of Bermuda killifishes (Fundulus) based on mitochondrial cytochrome b phylogenies SO CONSERVATION GENETICS LA English DT Article DE Fundulus; Bermuda; cytochrome b; evolutionarily significant units AB Sequence variation in the mitochondrial Cytochrome b (Cytb) gene was assayed in four of six extant Bermuda killifish populations, representing two endemic species, to test taxonomic and phylogenetic hypotheses and reconstruct colonization history. Two divergent (4.6%) haplotypes were detected; one is identical to the Georgia 2c haplotype of F. heteroclitus and is fixed in three eastern populations: Lover's Lake (F. relictus), Mangrove Lake (F. bermudae), and Walsingham Pond. The second is fixed and restricted to a western population, Evan's Pond. Likelihood and parsimony cytochrome b trees recognize a Bermuda Fundulus / F. heteroclitus clade in which the Evan's Pond haplotype is basal. Phylogenies and haplotype divergence indicate at least two Bermuda colonizations, the more recent involving transfer of the Georgia 2c haplotype. Enforcing Bermuda killifish monophyly, as predicted from a single colonization event, does not increase tree length significantly, i.e., the trees also are consistent with a single colonization. However, divergence between the Evan's Pond haplotype and the F. bermudae / F. relictus / Georgia 2c haplotype (4.6%) far exceeds the maximum divergence among all F. heteroclitus, F. bermudae, and F. heteroclitus haplotypes (1.2%) and argues for independent colonizations. Alternatively, recent introduction of F. heteroclitus could account for occurrence of the GA2c haplotype in Bermuda but does not explain the presence of the genetically divergent Evans' Pond haplotype. Cytb sequences are uninformative of the taxonomic status of Bermuda endemics, F. bermudae and F. relictus, but support recognition of the Evan's Pond population as an evolutionarily significant unit within the F. heteroclitus group. C1 [Grady, James M.] Univ New Orleans, Dept Biol Sci, New Orleans, LA 70148 USA. [Grady, James M.; Coykendall, D. K.] Univ S Carolina, Dept Biol Sci, Columbia, SC 29208 USA. [Collette, B. B.] Natl Museum Nat Hist, Natl Marine Fisheries Serv, Systemat Lab, Washington, DC 20560 USA. [Quattro, J. M.] Univ S Carolina, Dept Biol Sci, Marine Sci Program, Baruch Inst, Columbia, SC 29208 USA. [Quattro, J. M.] Univ S Carolina, Sch Environm, Columbia, SC 29208 USA. RP Grady, JM (reprint author), Univ New Orleans, Dept Biol Sci, New Orleans, LA 70148 USA. EM jgrady@uno.edu FU Louisiana Board of Regents [LEQSF (2000-01)-ENH-TR-67]; Department of Biological Sciences, University of New Orleans; Cooperative Institute for Fisheries Molecular Biology (FISHTEC) [NOAA/NMFS (RT/F-1), FT007]; National Science Foundation [OCE-9814172]; School of the Environment, University of South Carolina FX This study was made possible in part through the collecting efforts of W. Smith-Vaniz, who also provided critical information on the distribution and status of killifishes in Bermuda. C. Anderson, T. Merritt, and C. Young provided laboratory assistance. C. Bosworth, R. Deaton, L. Fassoni, J. Felley, S. Pelitire, J. Popham, A. Stokes, and E. Wiley offered invaluable comments on previous versions of the manuscript. This work was funded by the Louisiana Board of Regents Support Fund (LEQSF (2000-01)-ENH-TR-67) and the Department of Biological Sciences, University of New Orleans (to JMG) and the Cooperative Institute for Fisheries Molecular Biology (FISHTEC; NOAA/NMFS (RT/F-1) - contribution number FT007), National Science Foundation (OCE-9814172), and School of the Environment, University of South Carolina (to JMQ). NR 61 TC 3 Z9 6 U1 1 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1566-0621 J9 CONSERV GENET JI Conserv. Genet. PD MAR PY 2001 VL 2 IS 1 BP 41 EP 52 DI 10.1023/A:1011584318289 PG 12 WC Biodiversity Conservation; Genetics & Heredity SC Biodiversity & Conservation; Genetics & Heredity GA V22NN UT WOS:000208282000004 ER PT J AU Drazen, JC Buckley, TW Hoff, GR AF Drazen, JC Buckley, TW Hoff, GR TI The feeding habits of slope dwelling macrourid fishes in the eastern North Pacific SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article DE Macrouridae; feeding behaviour; scavengers; deep-sea fisheries; diets; North Pacific; USA ID DEEP-SEA; ATLANTIC-OCEAN; DEMERSAL FISHES; BENTHOPELAGIC FISHES; CONTINENTAL-SLOPE; FOOD-HABITS; STRATEGIES; OVERLAP; CORYPHAENOIDES-(NEMATONURUS)-ARMATUS; DISPERSAL AB The diet of slope dwelling macrourid fishes in the eastern North Pacific is poorly known. We collected several hundred stomach samples to investigate the feeding habits of Coryphaenoides acrolepis and Albatrossia pectoralis, the two dominant slope dwelling macrourids off the continental United States. Coryphaenoides acrolepis exhibited a pronounced ontogenetic shift in diet. Specimens < 15 cm pre-anal fin length (PAF) consumed primarily polychaetes, amphipods, cumaceans and mysids, while larger individuals consumed increasingly larger, more pelagic prey such as fish, squid, and large crustaceans. Scavenging was also very important to specimens > 15 cm with scavenged food constituting approximately 20% of the weight of total prey and occurring in approximately 20% of fish 21-29 cm. Albatrossia pectoralis consumed primarily midwater fish and squid, and we believe that it feeds in the water column. There were significant differences between the diets of A. pectoralis and C. acrolepis suggesting some degree of niche separation between macrourid species on the continental slope of the eastern North Pacific. Both species al-e at the top of the food web on the upper continental slope and, because of their abundance, may exert significant pressures on their prey populations. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif San Diego, Scripps Inst Oceanog, Marine Biol Res Div, La Jolla, CA 92093 USA. Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Seattle, WA 98115 USA. RP Drazen, JC (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Marine Biol Res Div, 9500 Gilman Dr, La Jolla, CA 92093 USA. RI Drazen, Jeffrey/C-1197-2013 OI Drazen, Jeffrey/0000-0001-9613-3833 NR 62 TC 47 Z9 48 U1 1 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD MAR PY 2001 VL 48 IS 3 BP 909 EP 935 DI 10.1016/S0967-0637(00)00058-3 PG 27 WC Oceanography SC Oceanography GA 377ZL UT WOS:000165556300013 ER PT J AU Fagan, WF Meir, E Prendergast, J Folarin, A Karieva, P AF Fagan, WF Meir, E Prendergast, J Folarin, A Karieva, P TI Characterizing population vulnerability for 758 species SO ECOLOGY LETTERS LA English DT Article DE biodiversity database; extinction risk; life history traits; population viability analysis; variation thresholds ID ENVIRONMENTAL STOCHASTICITY; R-SELECTION; K-SELECTION; EXTINCTION; CONSERVATION; DENSITY; PERSISTENCE; DYNAMICS; MODEL; TIMES AB We investigate relationships between life history traits and the character of population dynamics as revealed by time series data. Our classification of time series is according to 'extinction category,' where we identify three classes of populations: (i) weakly varying populations with such high growth rates that long-term persistence is likely (unless some extreme catastrophe occurs); (ii) populations with such low growth rates that average population size must be large to buffer them against extinction in a variable environment; and (iii) highly variable populations that fluctuate so dramatically that dispersal or some other refuge mechanism is likely to be key to their avoidance of extinction. Using 1941 time series representing 758 species from the Global Population Dynamics Database, we find that, depending on the form of density dependence one assumes, between 46 and 90% of species exhibit dynamics that are so variable that even large carrying capacities could not buffer them against extinction on a 100-year time horizon. The fact that such a large proportion of population dynamics are so locally variable vindicates the growing realization that dispersal, habitat connectedness, and large-scale processes are key to local persistence. Furthermore, for mammals, simply by knowing body size, age at first reproduction, and average number of offspring we could correctly predict extinction categories for 83% of species (60 of 72). C1 Natl Ctr Ecol Anal & Synth, Santa Barbara, CA 93101 USA. Arizona State Univ, Dept Biol, Tempe, AZ 85287 USA. Univ Washington, Dept Zool, Seattle, WA 98195 USA. Univ London Imperial Coll Sci Technol & Med, NERC, Ctr Populat Biol, Ascot SL5 7PY, Berks, England. Natl Marine Fisheries Serv, Seattle, WA 98112 USA. RP Fagan, WF (reprint author), Natl Ctr Ecol Anal & Synth, 735 State St Suite 300, Santa Barbara, CA 93101 USA. NR 35 TC 92 Z9 92 U1 6 U2 40 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1461-023X J9 ECOL LETT JI Ecol. Lett. PD MAR PY 2001 VL 4 IS 2 BP 132 EP 138 PG 7 WC Ecology SC Environmental Sciences & Ecology GA 415PH UT WOS:000167731300006 ER PT J AU Tyler, JA Brandt, SB AF Tyler, JA Brandt, SB TI Do spatial models of growth rate potential reflect fish growth in a heterogeneous environment? A comparison of model results SO ECOLOGY OF FRESHWATER FISH LA English DT Article DE growth rate potential; fish bioenergetics; individual-based model; habitat selection; habitat quality; fish growth; density dependence ID INDIVIDUAL-BASED MODEL; STIZOSTEDION-VITREUM-VITREUM; DIEL VERTICAL MIGRATION; IDEAL FREE DISTRIBUTION; LAKE-MICHIGAN; STRIPED BASS; EXPLICIT MODELS; BIOENERGETICS MODEL; PATCHY ENVIRONMENT; BRITISH-COLUMBIA AB Spatial models of fish growth rate potential have been used to characterize a variety of environments including estuaries, the North American Great Lakes, small lakes and rivers. Growth rate potential models capture a snapshot of the environment but do not include the effects of habitat selection or competition for food in their measures of environment quality. Here, we test the ability of spatial models of fish growth rate potential to describe the quality of an environment for a fish population in which individual fish may select habitats and local competition may affect pet capita intake. We compare growth rate potential measurements to simulated fish growth and distributions of model fish from a spatially explicit individual-based model of fish foraging in the same model environment. We base the model environment on data from Lake Ontario and base the model fish population on alewife in the lake. The results from a simulation experiment show that changes in the model environment that caused changes in the average growth rate potential correlated extremely highly (r(2)greater than or equal to0.97) with changes in simulated fish growth. Unfortunately, growth rate potential was not a reliable quantitative predictor of simulated fish growth nor of the fish spatial distribution. The inability of the growth rate potential model to quantitatively predict simulated fish growth and fish distributions results from the fact that growth rate potential does not consider the effects of habitat selection or of competition on fish growth or distribution, processes that operate in our individual-based model and presumably also operate in nature. The results, however, do support the use of growth rate potential models to describe the relative quality of habitats and environments for fish populations. C1 Worcester Polytech Inst, Dept Biol & Biotechnol, Worcester, MA 01609 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Tyler, JA (reprint author), Worcester Polytech Inst, Dept Biol & Biotechnol, 100 Inst Rd, Worcester, MA 01609 USA. EM tylerj@wpi.edu NR 59 TC 18 Z9 18 U1 0 U2 11 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0906-6691 EI 1600-0633 J9 ECOL FRESHW FISH JI Ecol. Freshw. Fish PD MAR PY 2001 VL 10 IS 1 BP 43 EP 56 DI 10.1034/j.1600-0633.2001.100106.x PG 14 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 420AK UT WOS:000167981600006 ER PT J AU Melo, AC Ramsdell, JS AF Melo, AC Ramsdell, JS TI Sexual dimorphism of brain aromatase activity in medaka: Induction of a female phenotype by estradiol SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE aromatase activity; endocrine disruption; medaka; sexual dimorphism ID RAT-BRAIN; CYTOCHROME-P450 AROMATASE; GENE-EXPRESSION; BEHAVIOR; AROMATIZATION; ESTROGEN; TISSUE; ORGANIZATION; TESTOSTERONE; INVITRO AB In this study we identified sex-dependent dimorphism of brain aromatase in the teleost medaka and examined its regulation by sex steriods. We first investigated differential distribution of brain aromatase activity in sexually mature male and female medaka in serial coronal sections of the brain and identified the hypothalamic nuclei contained in each section using the brain atlas of medaka. In the brain of male medaka, high levels of activity are localized in sections containing the preoptic (POA) and suprachiasmatic nuclei (SC) (63-75 fmol/hr) and low levels in the nuclei periventricular dorsalis (HD), ventralis (HV), and caudalis (Hc), nuclei diffusus of lobulus inferiores (NDIL), and nuclei tuberi anteriores (TA) and posteriores (TP) (< 25 fmol/hr). In the brain of female medaka high aromatase activity is localized in sections containing the HD, I-IV, Hc, NDIL, TA, and TP (85-80 fmol/hr) and highly variable levels in the POA and SC (23-70 fmol/hr). The concentration and time dependency of the exposure of male medaka to estradiol on the total brain aromatase activity and morphologic sex characteristics were determined next. Estradiol increased the activity of brain aromatase in a concentration-dependent manner at 2.5 and 25 g/L, but the increase was lower at higher concentrations of the hormone. The effect was time dependent, gradually increasing up to the fifth day of exposure, after which it reached a plateau. Estradiol induction of brain aromatase analyzed using Lineweaver-Burke plots of saturation assays revealed a non-first-order reaction. The results indicate that a positive Feedback mechanism regulates brain aromatase and imply that the sexual dimorphic distribution of aromatase may be highly sensitive to physiologic cues and environmental perturbations in fish. C1 NOAA, Coastal Res Branch, Ctr Coastal Environm Hlth & Biomol Res, Natl Ocean Serv,Marine Biotoxins Program, Charleston, SC 29412 USA. RP Ramsdell, JS (reprint author), NOAA, Coastal Res Branch, Ctr Coastal Environm Hlth & Biomol Res, Natl Ocean Serv,Marine Biotoxins Program, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 38 TC 59 Z9 59 U1 0 U2 3 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD MAR PY 2001 VL 109 IS 3 BP 257 EP 264 DI 10.2307/3434694 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 416HQ UT WOS:000167774600028 PM 11333187 ER PT J AU Mace, PM AF Mace, Pamela M. TI A new role for MSY in single-species and ecosystem approaches to fisheries stock assessment and management SO FISH AND FISHERIES LA English DT Article DE biological reference points; ecosystem approaches; fisheries management; fish stock assessments; maximum sustainable yield; precautionary approaches AB In 1977, Peter Larkin published his now-famous paper, An epitaph for the concept of maximum sustained yield'. Larkin criticized the concept of single-species maximum sustained yield (MSY) for many reasons, including the possibility that it may not guard against recruitment failure, and the impossibility of maximising sustainable yields for all species simultaneously. However, in recent years, there has been a fundamental change in the perception of the fishing mortality associated with MSY (F-MSY) as a limit to be avoided rather than a target that can routinely be exceeded. The concept of F-MSY as a limit is embodied in several United Nations Food and Agriculture Organization (FAO) agreements and guidelines, and has now been incorporated into the US Magnuson-Stevens Fishery Conservation and Management Act. As a result, the United States now requires the development of overfishing definitions based on biological reference points that treat the F-MSY as a limit reference point and must also define a lower limit on biomass below which rebuilding plans with strict time horizons must be developed. This represents a major paradigm shift from the previously mandated (but often unachieved) objective to simply maintain fishing mortalities at levels below those associated with recruitment overfishing. In many cases, it requires substantial reductions in current fishing mortality levels. Therefore, the necessity of the new paradigm is continually questioned. This paper draws on examples from several fisheries, but specifically focuses on the recent US experience illustrating the practical difficulties of reducing fishing mortality to levels below those corresponding to MSY. However, several studies suggest that even more substantial reductions in fishing mortality may be necessary if ecosystem considerations, such as multispecies interactions, maintenance of biodiversity and genetic diversity, and reduction of bycatch and waste, are taken into account. The pros and cons of moving beyond single-species assessment and management are discussed. A US plan for improving stock assessments indicates that even a 'basic' objective such as 'adequate baseline monitoring of all managed species' may be extremely costly. Thus, the suggestion of Larkin (1983, 1997) that the costs of research and management should not exceed 10-20% of the landed value of the catch may preclude comprehensive ecosystem management. More importantly, neither single-species nor ecosystem-based fisheries management is likely to improve appreciably unless levels of fishing capacity are aligned with resource productivity, as is currently being promoted by FAO and several individual nations. C1 Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. RP Mace, PM (reprint author), Natl Marine Fisheries Serv, 166 Water St, Woods Hole, MA 02543 USA. EM pamela.mace@noaa.gov FU Larkin family FX My sincere thanks to the Fisheries Centre at the University of British Columbia for the honour of being invited to present the 4th Larkin Lecture at the University of British Columbia, and to the Larkin family and friends for funding my visit. Thanks also to Steve Murawski for input to the construction of Figs 8-10, to two anonymous referees for constructive comments that helped to strengthen some of the arguments made in the paper, and to Chuck Hollingworth for detailed technical comments. NR 71 TC 163 Z9 168 U1 8 U2 76 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1467-2960 J9 FISH FISH JI Fish. Fish. PD MAR PY 2001 VL 2 IS 1 BP 2 EP 32 DI 10.1046/j.1467-2979.2001.00033.x PG 31 WC Fisheries SC Fisheries GA V22NK UT WOS:000208281700002 ER PT J AU Liermann, M Hilborn, R AF Liermann, Martin Hilborn, Ray TI Depensation: evidence, models and implications SO FISH AND FISHERIES LA English DT Article DE Allee effect; depensation; inverse density dependence AB We review the evidence supporting depensation, describe models of two depensatory mechanisms and how they can be included in population dynamics models and discuss the implications of depensation. The evidence for depensation can be grouped into four mechanisms: reduced probability of fertilisation, impaired group dynamics, conditioning of the environment and predator saturation. Examples of these mechanisms come from a broad range of species including fishes, arthropods, birds, mammals and plants. Despite the large number of studies supporting depensatory mechanisms, there is very little evidence of depensation that is strong enough to be important in a population's dynamics. However, because factors such as demographic and environmental variability make depensatory population dynamics difficult to detect, this lack of evidence should not be interpreted as evidence that depensatory dynamics are rare and unimportant. The majority of depensatory models are based on reduced probability of fertilisation and predator saturation. We review the models of these mechanisms and different ways they can be incorporated in population dynamics models. Finally, we discuss how depensation may affect optimal harvesting, pest control and population viability analysis. C1 [Liermann, Martin] Univ Washington, Seattle, WA 98115 USA. [Hilborn, Ray] Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. RP Liermann, M (reprint author), NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM martin.liermann@noaa.gov RI Hilborn, Ray/D-6332-2013 NR 114 TC 128 Z9 132 U1 2 U2 23 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1467-2960 J9 FISH FISH JI Fish. Fish. PD MAR PY 2001 VL 2 IS 1 BP 33 EP 58 DI 10.1046/j.1467-2979.2001.00029.x PG 26 WC Fisheries SC Fisheries GA V22NK UT WOS:000208281700003 ER PT J AU Logerwell, EA Smith, PE AF Logerwell, EA Smith, PE TI Mesoscale eddies and survival of late stage Pacific sardine (Sardinops sagax) larvae SO FISHERIES OCEANOGRAPHY LA English DT Article DE California Cooperative Oceanic Fisheries Investigations; California Current; mesoscale eddies; Pacific sardine; prerecruit survival; Sardinops sagax ID CALIFORNIA CURRENT SYSTEM; OFFSHORE EDDY; TRACHURUS-SYMMETRICUS; MERLUCCIUS-PRODUCTUS; ENGRAULIS-MORDAX; ANCHOVY; DISTRIBUTIONS; OCEANOGRAPHY; VARIABILITY; RECRUITMENT AB We examined the distribution of sardine larvae relative to environmental conditions with the purpose of identifying and characterizing habitat that encourages high larval growth and survival, based on the 1983-1998 surveys of the California Cooperative Oceanic Fisheries Investigations (CalCOFI). Long-term averages show that sardine 'survivors' (spatially aggregated larvae greater than or equal to 18 days old) were most abundant offshore, whereas sardine egg density, chlorophyll biomass and zooplankton volume were greatest inshore. In contrast, mesoscale eddies, observed in remotely sensed sea surface temperature imagery, were found only in offshore regions. To further examine the link between eddies - which often result in locally elevated chlorophyll and zooplankton - and sardine survival, we compared the distribution of larvae and eddies survey by survey. Sardine survivors were most abundant offshore in only one-quarter of the research surveys, and when they were most abundant offshore they were associated with eddies. This indicates that the offshore eddy habitat produced exceptionally large numbers of survivors, as evidenced by the disproportionate effect on the long-term average. C1 SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Logerwell, EA (reprint author), Univ Washington, Sch Aquat & Fishery Sci, Box 3550020, Seattle, WA 98195 USA. EM libbyl@u.washington.edu NR 65 TC 84 Z9 85 U1 1 U2 9 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 2001 VL 10 IS 1 BP 13 EP 25 DI 10.1046/j.1365-2419.2001.00152.x PG 13 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 430JY UT WOS:000168571800002 ER PT J AU Napp, JM Hunt, GL AF Napp, JM Hunt, GL TI Anomalous conditions in the south-eastern Bering Sea 1997: linkages among climate, weather, ocean, and Biology SO FISHERIES OCEANOGRAPHY LA English DT Article DE apex predators; Bering Sea; biogeochemical cycles; climate change; Emiliania huxleyi; food webs; marine ecosystems ID COCCOLITHOPHORE EMILIANIA-HUXLEYI; PRIBILOF-ISLANDS; BLOOMS; SHELF; PACIFIC; MAINE; GULF; ZOOPLANKTON; ENVIRONMENT; SATELLITE AB In 1997, the Bering Sea ecosystem, a productive, high-latitude marginal sea, demonstrated that it responds on very short time scales to atmospheric anomalies. That year, a combination of atmospheric mechanisms produced notable summer weather anomalies over the eastern Bering Sea. Calm winds, clear skies, and warm air temperatures resulted in a larger-than-normal transfer of heat to surface waters and the establishment of a shallow mixed layer. In spring, significant new production occurred below the shallow pycnocline over the Middle Shelf, depleting the subpycnocline nutrient reservoir that normally exists during summer. Following the depletion of nitrate and silicate from the system, a sustained (greater than or equal to 4 months) bloom of coccolithophores (Emiliania huxleyi) was observed - a phenomenon not previously documented in this region. Summer Middle Shelf Domain copepod concentrations were higher for some species in 1997 than in the early 1980s. Warmer surface water and lack of wind mixing also changed the basic distribution of hydrographic regimes on the south-eastern shelf and altered the strength and position of fronts or transition zones where apex predators seek elevated food concentrations. The Inner Front was well inshore of its normal position, and adult euphausiids (the primary prey of short-tailed shearwaters, Puffinus tenuirostris) were unavailable at, and shoreward of, the front in autumn. High shearwater mortality rates followed the period of low euphausiid availability. Some, but not all, of these anomalous conditions re-occurred in 1998. These observations are another demonstration that the structure and function of marine ecosystems are intimately tied to forcing from the atmosphere. Alteration of climatological forcing functions, expressed as weather, can be expected to have large impacts on this ecosystem and its natural resources. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. Univ Calif Irvine, Dept Ecol & Evolutionary Biol, Irvine, CA 92697 USA. RP Napp, JM (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. OI Hunt, George/0000-0001-8709-2697 NR 50 TC 107 Z9 109 U1 1 U2 9 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 2001 VL 10 IS 1 BP 61 EP 68 DI 10.1046/j.1365-2419.2001.00155.x PG 8 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 430JY UT WOS:000168571800006 ER PT J AU Overland, JE Bond, NA Adams, JM AF Overland, JE Bond, NA Adams, JM TI North Pacific atmospheric and SST anomalies in 1997: Links to ENSO? SO FISHERIES OCEANOGRAPHY LA English DT Article ID SEA-SURFACE TEMPERATURE; CIRCULATION; OSCILLATION; TELECONNECTIONS AB In the summer of 1997, positive sea surface temperature anomalies (SSTA) extended across the Gulf of Alaska (GOA) and into the eastern Bering Sea (EBS). The SSTA in the EBS are at least in part due to atmospheric causes. Anomalously high 925 mb temperatures and 700 mb geopotential heights and low 925 mb relative humidities, and hence decreased low cloud cover, occurred over the region during April to August. This resulted in enhanced warming of the GOA and EBS owing to increased insolation. The anomalous solar heating was particularly great in the EBS from mid-May to mid-July. The pattern of positive 700 mb height anomalies for April to August 1997 is similar to its counterpart formed by compositing the April to August anomalies that occurred during previous El Ninos. The positive equatorial SSTA for 1997 was one of the strongest on record for summer months. The existence of an equatorial/high-latitude connection and the strength of the summer equatorial SSTA in 1997 suggest an El Nino/Southern Oscillation (ENSO) influence in the GOA and EBS. The warming in the Bering Sea and North Pacific during summer 1997 appears to be due in part to the confluence of three meteorological factors which favoured clear skies. There was not only an El Nino influence, but also a decadal trend toward higher 700 mb geopotential heights and a particularly strong blocking ridge weather pattern over the Gulf of Alaska in May. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, JISAO, Seattle, WA 98195 USA. RP Overland, JE (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 23 TC 52 Z9 54 U1 0 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 2001 VL 10 IS 1 BP 69 EP 80 DI 10.1046/j.1365-2419.2001.00154.x PG 12 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 430JY UT WOS:000168571800007 ER PT J AU Stabeno, PJ Bond, NA Kachel, NB Salo, SA Schumacher, JD AF Stabeno, PJ Bond, NA Kachel, NB Salo, SA Schumacher, JD TI On the temporal variability of the physical environment over the south-eastern Bering Sea SO FISHERIES OCEANOGRAPHY LA English DT Article ID SPRING BLOOM; ICE EDGE; PACIFIC; SHELF; CIRCULATION; OSCILLATION; OCEAN AB During 1997 and 1998, unusual physical conditions occurred in the Bering Sea: strong May storms and calm conditions in July; record high sea surface temperature; a shallow wind mixed layer; a fresher-than-normal water column; and abnormal cross-shelf currents. Accompanying these conditions were changes in the dominant phytoplankton, a die-off of seabirds, increased sightings of large whales and diminished returns of salmon. Changes to the physical environment during 1997 and 1998 are placed in context of historical meteorological and oceanographic data sets. Although 1997 had the warmest sea surface temperature ever observed on the south-east Bering Sea shelf, the heat content of the water column was cooler than average. In contrast, during 1998, the sea surface temperature was cooler than in 1997 but the water column had significantly higher heat content. During recent years, the water column has freshened over the middle shelf because of increased sea ice and reduction of on-shelf transport of the saline, high-nutrient water from the slope. The timing of the spring bloom is directly related to the presence of ice. When ice is advected over the south-east shelf during March/April an early, sharp phytoplankton bloom occurs. The absence of ice during this critical time is associated with a May/June bloom. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, JISAO, Seattle, WA 98195 USA. Two Crow Environm Consultants, Silver City, NM USA. RP Stabeno, PJ (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 35 TC 224 Z9 231 U1 1 U2 23 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 2001 VL 10 IS 1 BP 81 EP 98 DI 10.1046/j.1365-2419.2001.00157.x PG 18 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 430JY UT WOS:000168571800008 ER PT J AU Stockwell, DA Whitledge, TE Zeeman, SI Coyle, KO Napp, JM Brodeur, RD Pinchuk, AI Hunt, GL AF Stockwell, DA Whitledge, TE Zeeman, SI Coyle, KO Napp, JM Brodeur, RD Pinchuk, AI Hunt, GL TI Anomalous conditions in the south-eastern Bering Sea, 1997: nutrients, phytoplankton and zooplankton SO FISHERIES OCEANOGRAPHY LA English DT Article DE Bering Sea; coccolithophorids; Emiliania huxleyi; nutrients; productivity; zooplankton ID POLLOCK THERAGRA-CHALCOGRAMMA; EMILIANIA-HUXLEYI; THYSANOESSA-INERMIS; SHELF-EDGE; COCCOLITHOPHORE; DYNAMICS; BLOOMS; GROWTH; PHOTOSYNTHESIS; VARIABILITY AB Anomalies in the regional weather over the south-eastern Bering Sea during spring and summer of 1997 resulted in significant differences in nutrient availability, phytoplankton species composition, and zooplankton abundance over the continental shelf as compared with measurements in the 1980s. Calm winds and the reduction of cloud cover in spring and summer produced a very shallow mixed layer in which nitrate and silicate were depleted after an April diatom bloom. High submarine light levels allowed subsequent phytoplankton growth below the pycnocline and eventual depletion of nitrate from the water column to depths of 70 m or more. Thus, total new production during 1997 may have exceeded that of previous years when nitrate was not depleted below the pycnocline. A bloom of the coccolithophorid, Emiliania huxleyi, was observed in early July in the warm, nutrient-depleted waters over the middle and inner shelf. Emiliania huxleyi concentrations reached 4.5 x 10(6) cells L-1 by September, and the bloom persisted through the autumn. There was evidence for increased abundance of some species of copepods in 1997 as compared with data from the middle domain in June 1981. The abundance of adult and juvenile euphausiids in 1997 was statistically similar to values measured in 1980 and 1981. However, near-surface swarms were rarely observed on the inner shelf in August-September 1997. Lack of euphausiid availability in the upper water column may partially explain the August-September mass mortality of planktivorous short-tailed shearwaters (Puffinus tenuirostris) observed on the inner shelf. C1 Univ Alaska Fairbanks, Fairbanks, AK 99775 USA. Univ New England, Biddeford, ME 04005 USA. NOAA, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. NOAA, NW Fisheries Sci Ctr, Newport, OR 97365 USA. Univ Calif Irvine, Irvine, CA 92697 USA. RP Whitledge, TE (reprint author), Univ Alaska Fairbanks, Fairbanks, AK 99775 USA. OI Hunt, George/0000-0001-8709-2697 NR 72 TC 96 Z9 99 U1 0 U2 6 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD MAR PY 2001 VL 10 IS 1 BP 99 EP 116 DI 10.1046/j.1365-2419.2001.00158.x PG 18 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 430JY UT WOS:000168571800009 ER PT J AU Weber, LA AF Weber, LA TI Measurement of the solubility of water in 2,2-dichloro-1,1,1-trifluoroethane (HCFC 123) SO FLUID PHASE EQUILIBRIA LA English DT Article DE 2,2-dichloro-1,1,1-trifluoroethane; activity coefficient; azeotrope; ebulliometry; solubility; water; CAS registry number 306-83-2 ID THERMODYNAMIC PROPERTIES; VAPOR-PRESSURE; 1,1-DICHLORO-2,2,2-TRIFLUOROETHANE AB A metal ebulliometer has been used to measure the solubility of water in 2,2-dichloro-1,1,1-trifluoroethane (HCFC 123) over the temperature range 297-354 K. Solubilities varied from 9.5 x 10(-3) to 3.75 x 10(-2) (mole fraction). Activity coefficients (gamma (infinity)) and distribution coefficients (KW) were estimated. The results were used to resolve a discrepancy found in the literature concerning the vapor pressure of HCFC 123. (C) 2001 Elsevier Science B.V. All rights reserved. C1 NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Weber, LA (reprint author), NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 10 TC 1 Z9 1 U1 2 U2 2 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 MAR 1 PY 2001 VL 178 IS 1-2 BP 203 EP 208 DI 10.1016/S0378-3812(00)00462-3 PG 6 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 413HP UT WOS:000167607200014 ER PT J AU Bruno, TJ Rybowiak, MC AF Bruno, TJ Rybowiak, MC TI Vapor entraining magnetic mixer for reaction and equilibrium applications SO FLUID PHASE EQUILIBRIA LA English DT Article DE mixing; reaction vessel; vapor entrainment; vapor-liquid equilibrium AB Mixing of fluids is a central component to innumerable operations in chemical processing on the plant floor and also in many laboratory operations. Most mixing applications simply require the efficient blending of fluids present in a single phase, such as the mixing of the individual components of a liquid. For these applications, magnetic stirrers often prov ide a convenient and efficient blending without creating ambient air entertainment into the liquid. This is especially true of fluid mixing operations done in the laboratory. There are many other applications, however, in which the entertainment of a vapor phase with a liquid is specifically desired. Examples of these applications include mixing in two-phase reaction vessels and in apparatus to measure vapor-liquid equilibrium. These mixing operations are difficult to accommodate with magnetic stirrers because the vast majority of such stirrers are designed not to entrain vapor. In this brief paper, we present a novel design of a mixing rotor that efficiently mixes the liquid phase and also achieves entrainment of vapor in the liquid. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Bruno, TJ (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 9 TC 7 Z9 7 U1 0 U2 0 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 MAR 1 PY 2001 VL 178 IS 1-2 BP 271 EP 276 DI 10.1016/S0378-3812(00)00473-8 PG 6 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 413HP UT WOS:000167607200020 ER PT J AU Hoerling, MP Whitaker, JS Kumar, A Wang, WQ AF Hoerling, MP Whitaker, JS Kumar, A Wang, WQ TI The midlatitude warming during 1998-2000 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Large scale tropospheric warming of the Northern and Southern Hemisphere extratropics occurred during the period January 1998-January 2000. The anomalies were remarkable for their amplitude, their persistence, their zonal symmetry with warming occurring at all longitudes between 30-50 degrees latitude, and their axial symmetry with respect to the equator. The origin of the anomalies are investigated using atmospheric general circulation models forced by the global sea surface temperatures (SSTs) of this period. Two ensembles, based on different models, reproduce the key observed features indicating that the unusual climate state was forced by the global SSTs. However, the atmospheric states were unrelated to the strong and protracted La Nina of the east equatorial Pacific Ocean during this time. We speculate on the role of the Indo-Pacific warm pool, which itself experienced unprecedented warming in 1998 and 1999. C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80305 USA. NOAA, NWS, NCEP, EMC,Climate Modeling Branch, Camp Springs, MD 20746 USA. RP Hoerling, MP (reprint author), NOAA, CIRES, Climate Diagnost Ctr, 325 Broadway R-DCDC1, Boulder, CO 80305 USA. NR 8 TC 24 Z9 24 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 MAR 1 PY 2001 VL 28 IS 5 BP 755 EP 758 DI 10.1029/2000GL012137 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 406RV UT WOS:000167229700003 ER PT J AU Coatanoan, C Goyet, C Gruber, N Sabine, CL Warner, M AF Coatanoan, C Goyet, C Gruber, N Sabine, CL Warner, M TI Comparison of two approaches to quantify anthropogenic CO2 in the ocean: Results from the northern Indian Ocean SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID ARABIAN SEA; RED-SEA; HYDROGRAPHIC SECTION; ATLANTIC-OCEAN; WATER; VENTILATION; CHLOROFLUOROCARBONS; DENITRIFICATION; THERMOCLINE; ALKALINITY AB This study compares two recent estimates of anthropogenic CO2 in the northern Indian Ocean along the World Ocean Circulation Experiment cruise I1 [Goyet et al., 1999; Sabine et al., 1999]. These two studies employed two different approaches to separate the anthropogenic CO2 signal from the large natural background variability. Sabine et al. [1999] used the DeltaC* approach first described by Gruber et al. [1996], whereas Goyet et al. [1999] used an optimum multiparameter mixing analysis referred to as the MIX approach. Both approaches make use of similar assumptions in order to remove variations due to remineralization of organic matter and the dissolution of calcium carbonates (biological pumps). However, the two approaches use very different hypotheses in order to account for variations due to physical processes including mixing and the CO2 solubility pump. Consequently, substantial differences exist in the upper thermocline approximately between 200 and 600 m. Anthropogenic CO2 concentrations estimated using the DeltaC* approach average 12 +/- 4 mu mol kg(-1) higher in this depth range than concentrations estimated using the MIX approach, Below similar to 800 m, the MIX approach estimates slightly higher anthropogenic CO2 concentrations and a deeper vertical penetration. Despite this compensatory effect, water column inventories estimated in the 0-3000 m depth range by the DeltaC* approach are generally similar to 20% higher than those estimated by the MIX approach, with this difference being statistically significant beyond the 0.001 level. We examine possible causes for these differences and identify a number of critical additional measurements that will make it possible to discriminate better between the two approaches. C1 Woods Hole Oceanog Inst, Marine Chem & Geochem Dept, Woods Hole, MA 02543 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ USA. Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. RP Coatanoan, C (reprint author), Woods Hole Oceanog Inst, Marine Chem & Geochem Dept, Woods Hole, MA 02543 USA. RI Coatanoan, Christine/A-4497-2010; Gruber, Nicolas/B-7013-2009; OI Gruber, Nicolas/0000-0002-2085-2310; COATANOAN, Christine/0000-0001-9387-1793 NR 43 TC 24 Z9 24 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD MAR PY 2001 VL 15 IS 1 BP 11 EP 25 DI 10.1029/1999GB001200 PG 15 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 417RW UT WOS:000167848800002 ER PT J AU Sabine, CL Feely, RA AF Sabine, CL Feely, RA TI Comparison of recent Indian Ocean anthropogenic CO2 estimates with a historical approach SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID INORGANIC CARBON MEASUREMENTS; TOTAL ALKALINITY; ATLANTIC-OCEAN; INCREASE; DIOXIDE; SEAWATER; WATER; SEA; QUANTIFICATION; NITROGEN AB This work compares the classic Chen and Millero [1979] approach for estimating anthropogenic CO2 from ocean carbon measurements with the more recent DeltaC* technique used by Sabine et al. [1999] to estimate anthropogenic CO2 concentrations in the Indian Ocean. Application of the Chen technique to the WOCE/JGOFS Indian Ocean data set gives a total anthropogenic CO2 inventory that is essentially the same as the DeltaC* inventory, but there are substantial differences in the distributions within the water column. Some of these differences result from details of the application of the techniques such as the choice of which equation to use for the preformed alkalinity concentration or the choice of stoichiometric ratio to use for the biological correction. More significant differences, however, result from two fundamental differences in the techniques. One fundamental difference between the two techniques is that changes in the properties of the subsurface waters are referenced to a single deep water value in the Chen approach instead of the multiple reference points from the isopycnal analysis used in the DeltaC* approach. The second fundamental difference is in the estimation of the preindustrial TCO2 distribution. Many of the differences examined have counteracting effects that may result in a total anthropogenic CO2 inventory that is similar for the two techniques. However, this similarity does not imply that both approaches are right. Comparison with global carbon models and other measurement-based techniques do not clearly demonstrate that one technique is better than another. However, given the additional constraints of the transient tracers and the isopycnal analysis, we believe that the DeltaC* technique provides a more robust estimate. C1 Univ Washington, Joint Inst Study Atmosphere & Oceans, NOAA, PMEL, Seattle, WA 98115 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Sabine, CL (reprint author), Univ Washington, Joint Inst Study Atmosphere & Oceans, NOAA, PMEL, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 43 TC 26 Z9 27 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD MAR PY 2001 VL 15 IS 1 BP 31 EP 42 DI 10.1029/2000GB001258 PG 12 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 417RW UT WOS:000167848800004 ER PT J AU Orr, JC Maier-Reimer, E Mikolajewicz, U Monfray, P Sarmiento, JL Toggweiler, JR Taylor, NK Palmer, J Gruber, N Sabine, CL Le Quere, C Key, RM Boutin, J AF Orr, JC Maier-Reimer, E Mikolajewicz, U Monfray, P Sarmiento, JL Toggweiler, JR Taylor, NK Palmer, J Gruber, N Sabine, CL Le Quere, C Key, RM Boutin, J TI Estimates of anthropogenic carbon uptake from four three-dimensional global ocean models SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID GENERAL-CIRCULATION MODEL; ATLANTIC-OCEAN; EQUATORIAL PACIFIC; NONUNIFORM GRIDS; NET DIFFUSIVITY; NORTH-ATLANTIC; STEADY-STATE; CO2 FLUXES; RADIOCARBON; SIMULATIONS AB We have compared simulations of anthropogenic CO2 in the four three-dimensional ocean models that participated in the first phase of the Ocean Carbon-Cycle Model Intercomparison Project (OCMIP), as a means to identify their major differences. Simulated global uptake agrees to within +/- 19%, giving a range of 1.85 +/-0.35 Pg C yr(-1) for the 1980-1989 average, Regionally, the Southern Ocean dominates the present-day air-sea flux of anthropogenic CO2 in all models, with one third to one half of the global uptake occurring south of 30 degreesS. The highest simulated total uptake in the Southern Ocean was 70% larger than the lowest. Comparison with recent data-based estimates of anthropogenic CO2 suggest that most of the models substantially overestimate storage in the Southern Ocean; elsewhere they generally underestimate storage by less than 20%. Globally, the OCMIP models appear to bracket the real ocean's present uptake, based on comparison of regional data-based estimates of anthropogenic CO2 and bomb C-14. Column inventories of bomb C-14 have become more similar to those for anthropogenic CO2 with the time that has elapsed between the Geochemical Ocean Sections Study (1970s) and World Ocean Circulation Experiment (1990s) global sampling campaigns. Our ability to evaluate simulated anthropogenic CO2 would improve if systematic errors associated with the data-based estimates could be provided regionally. C1 CEA Saclay, Lab Sci Climat Environnement, CNRS, F-91191 Gif Sur Yvette, France. Inst Pierre Simon Laplace, Paris, France. Max Planck Inst Meteorol, Hamburg, Germany. Princeton Univ, Atmospher & Ocean Sci AOS Program, Princeton, NJ 08544 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. Meteorol Off, Hadley Ctr Climate Predict & Res, Bracknell RG12 2SZ, Berks, England. Univ Bern, Inst Phys, Bern, Switzerland. Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. Univ Paris 06, Lab Oceanog Dynam & Climatol, F-75252 Paris 05, France. RP Orr, JC (reprint author), CEA Saclay, Lab Sci Climat Environnement, CNRS, Bat 709, F-91191 Gif Sur Yvette, France. RI Orr, James/C-5221-2009; Gruber, Nicolas/B-7013-2009; Boutin, Jacqueline/M-2253-2016; Le Quere, Corinne/C-2631-2017; OI Gruber, Nicolas/0000-0002-2085-2310; Le Quere, Corinne/0000-0003-2319-0452; Orr, James/0000-0002-8707-7080 NR 64 TC 189 Z9 198 U1 1 U2 28 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD MAR PY 2001 VL 15 IS 1 BP 43 EP 60 DI 10.1029/2000GB001273 PG 18 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 417RW UT WOS:000167848800005 ER PT J AU Dyer, SD Rochford, KB AF Dyer, SD Rochford, KB TI Low-coherence interferometric measurements of the dispersion of multiple fiber Bragg gratings SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE chromatic dispersion; fiber Bragg grating; group delay; interferometry; optical fibers; white light AB We show that the dispersion of multiple fiber Bragg gratings can be obtained from a single low-coherence interferometric measurement. The individual gratings can be identified either from the spatial separation of the interferometric signatures or from the unique wavelength-reflection bands of the gratings. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80305 USA. RP Dyer, SD (reprint author), Natl Inst Stand & Technol, Div Optoelect, 325 Broadway, Boulder, CO 80305 USA. NR 9 TC 10 Z9 11 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 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD MAR PY 2001 VL 13 IS 3 BP 230 EP 232 DI 10.1109/68.914330 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 418CT UT WOS:000167872700020 ER PT J AU Rabin, MW Hilton, GC Martinis, JM AF Rabin, MW Hilton, GC Martinis, JM TI Application of microcalorimeter energy measurement to biopolymer mass spectrometry SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE electrospray ionization mass spectrometry; (ESI-MS); ion energy; microcalorimeter; mixture analysis ID TIME; MACROMOLECULES; DETECTORS; JUNCTIONS AB We have performed electrospray ionization mass spectrometry using a magnetic-sector mass spectrometer of proteins, detecting the ions with a normal-insulator-superconductor microcalorimeter detector. We emphasize the measurement of ion-impact energy as a way to obtain extra information that is unavailable in normal mass spectrometry, Energy measurements are used to discriminate against erroneous ion-strikes, to resolve ambiguities that cannot be resolved by normal mass spectrometry, and to illustrate some of the performance limits of the current detector design. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Rabin, MW (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 16 TC 1 Z9 1 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 242 EP 247 DI 10.1109/77.919329 PN 1 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HP UT WOS:000168285400048 ER PT J AU Deiker, S Chervenak, J Hilton, GC Irwin, KD Martinis, JM Nam, S Wollman, DA AF Deiker, S Chervenak, J Hilton, GC Irwin, KD Martinis, JM Nam, S Wollman, DA TI Transition edge sensor array development SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE transition edge sensors; microcalorimeters; cryogenic detectors; detector arrays; x-ray astronomy; microanalysis ID EV ENERGY RESOLUTION; MICROCALORIMETER; SPECTROMETER AB NIST is fabricating multi-pixel arrays of transition edge sensor (TES) microcalorimeter detectors for use in microanalysis and x-ray astrophysics, We have developed both room temperature digital feedback electronics and a successful SQUID multiplexing technology that will be applied to form a practical, expandable system. We are also exploring surface micromachining techniques to enable the fabrication of large-scale, close-packed arrays of TES microcalorimeters. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Deiker, S (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 9 TC 5 Z9 5 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 469 EP 472 DI 10.1109/77.919384 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HP UT WOS:000168285400103 ER PT J AU Chervenak, JA Grossman, EN Reintsema, CD Irwin, KD Moseley, SH Allen, CA AF Chervenak, JA Grossman, EN Reintsema, CD Irwin, KD Moseley, SH Allen, CA TI Sub-picowatt precision radiometry using superconducting transition edge sensor bolometers SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE blackbody; bolometer; radiometer; sub-millimeter ID ELECTROTHERMAL FEEDBACK AB We describe a cryogenic radiometric calibration system suitable for high sensitivity, low background power bolometers, The system uses a variable temperature blackbody source capable of temperatures of 4 to 20 K, whose output covers the sub-millimeter wavelength regime. The detector is an eight-channel, filled-focal-plane array of superconducting transition edge sensor (TES) bolometers, The system is designed to test components of the optical system such as polarizers, filters and stray light suppressors as well as the performance of the detector array elements, The bolometer response to incident submillimeter radiation is measured and compared to the calculated output of the source seen by the bolometer. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Chervenak, JA (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 5 TC 3 Z9 3 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 593 EP 596 DI 10.1109/77.919415 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HP UT WOS:000168285400134 ER PT J AU Hilton, GC Martinis, JM Irwin, KD Bergren, NF Wollman, DA Huber, ME Deiker, S Nam, SW AF Hilton, GC Martinis, JM Irwin, KD Bergren, NF Wollman, DA Huber, ME Deiker, S Nam, SW TI Microfabricated transition-edge x-ray detectors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE x-ray detectors; IR detectors; microcalorimeter; x-ray spectrometry ID EV ENERGY RESOLUTION; MICROCALORIMETER; SPECTROSCOPY; THERMOMETERS; ARRAYS AB We are developing high performance x-ray detectors based on superconducting transition-edge sensors (TES) for application in materials analysis and astronomy. Using our recently developed fully lithographic TES fabrication process, we have made devices with an energy resolution of 4.5 +/- 0.1 eV for 5.9 keV x-rays, the best reported energy resolution for any energy dispersive detectors in this energy range. These detectors utilize micromachined thermal isolation structures and transition-edge sensors fabricated from Mo/Cu bilayers with normal-metal boundary conditions. We have found the normal-metal boundary conditions to be critical to stable and reproducible low noise operation. In this paper we present details of fabrication and performance of these devices. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Univ Colorado, Dept Phys, Denver, CO 80217 USA. RP Hilton, GC (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. RI Huber, Martin/B-3354-2011 NR 13 TC 59 Z9 60 U1 0 U2 13 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 739 EP 742 DI 10.1109/77.919451 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HP UT WOS:000168285400170 ER PT J AU Vale, LR Ono, RH AF Vale, LR Ono, RH TI Small area Y-Ba-Cu-O thin films for applications in hot-electron bolometers SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE hot-electron bolometer; Si substrates; thin film growth; Y-Ba-Cu-O ID TERAHERTZ APPLICATIONS; MIXERS; FABRICATION AB We are investigating the use of very thin, small area YBa2Cu3O7-x (YBCO) films on Si substrates for application in hot-electron bolometers. Hot-electron bolometers produced from high-T-C materials will be favored over their low-temperature counterparts in applications of radio astronomy and atmospheric physics where the higher operating temperatures provide distinct advantages. Devices on Si can help advance this technology for bolometric space applications, where a substrate is needed with good thermal conductance and excellent IR performance, Based on our experience with YBCO bolometers and YBCO film growth on Si, we have begun a study of sub-micrometer scale devices. Our typical YBCO films grown on Si by pulsed laser deposition have critical temperatures of 86 K and critical currents of 1-3 x10(6) A/cm(2) at 77 K for YBCO microbridges 45 nm thick, We have made 1-2 mum wide microbridges from YBCO films of 25 nm to 45 nm thick. These microbridges show reduced critical temperatures of 71 K to 81 K, respectively, related to the processing sequence that produces the microbridges. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Vale, LR (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 5 TC 4 Z9 4 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 762 EP 765 DI 10.1109/77.919457 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HP UT WOS:000168285400176 ER PT J AU Kautz, RL AF Kautz, RL TI Jim Zimmerman and the SQUID SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA ID MAGNETOMETER; OPERATION; DEVICES AB The career of Jim Zimmerman, beginning with a solid foundation in electronics and cryogenics, reached a turning point in 1965 when he became coinventor of the rf SQUID (Superconducting QUantum Interference Device), while working at the Scientific Laboratory of the Ford Motor Company in Dearborn, Michigan. Recognizing the exquisite sensitivity of the SQUID as an amplifier and magnetometer, Zimmerman devoted the remainder of his career, at Ford and later at the National Bureau of Standards, to the further development of the SQUID and its applications. In 1969, Zimmerman also helped found SHE Corporation, which marketed the first commercially successful SQUID. While at NBS, Zimmerman introduced two variations, the SQUID gradiometer and the fractional-turn SQUID, to enhance the sensitivity of SQUIDs in special situations. He also developed an improved understanding of SQUID dynamics by exploring the pendulum analog using carefully made models, work that has benefited a generation of students. Putting the SQUID to work, Zimmerman investigated applications in metrology, biomagnetism, and geophysics. Notably, he participated in collaborations that recorded the first magnetocardiogram made with a SQUID and the first magnetoencephalogram of an evoked auditory response. Later, Zimmerman explored closed-cycle refrigeration as a means of making SQUIDs more useful outside the laboratory environment, and in 1977 he demonstrated an operating SQUID cooled to 8.5 K by a Stirling-cycle refrigerator made largely of plastic. Zimmerman is remembered for his keen physical insight, the elegance and simplicity of his experiments, and his willingness to question conventional wisdom in all aspects of life. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Kautz, RL (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80305 USA. NR 33 TC 1 Z9 1 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 1026 EP 1031 DI 10.1109/77.919524 PN 1 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HP UT WOS:000168285400241 ER PT J AU Huber, ME Neil, PA Benson, RG Burns, DA Corey, AM Flynn, CS Kitaygorodskaya, Y Massihzadeh, O Martinis, JM Hilton, GC AF Huber, ME Neil, PA Benson, RG Burns, DA Corey, AM Flynn, CS Kitaygorodskaya, Y Massihzadeh, O Martinis, JM Hilton, GC TI DC SQUID series array amplifiers with 120 MHz bandwidth SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE resonances; SQUIDs; SQUID series arrays; superconducting devices ID MULTITURN INPUT COIL; ELECTROTHERMAL FEEDBACK AB We report on the performance of de SQUID (Superconducting Quantum Interference Device) series array amplifiers from de to 500 MHz. The arrays consist of up to 100 de SQUIDs, with varying degrees of intracoil damping; the flux-focusing washer of each SQUID is electrically isolated from the SQUID loop (L-sq = 18 pH). Using an rf network analyzer, we have observed high-frequency resonances in the response at bias points corresponding to distortions in the de transfer functions. Increasing distance between SQUIDs in the array reduces the distortions. Distortions are also more pronounced, and bandwidth reduced, in devices incorporating the flux-focusing washer into the SQUID body. With intracoil damping of 0.25 Omega per turn on the input coil, the voltage-flux transfer characteristics of the isolated-washer design and 300 pm center-to-center SQUID spacing are free of significant distortions, and the bandwidth is not degraded compared to undamped devices. The 100-SQUID array has 150 nH input inductance, 500 V/A transimpedance, 2.5 pA/ Hz equivalent input current noise at 4 K, and 120 MHz bandwidth. C1 Univ Colorado, Dept Phys, Denver, CO 80217 USA. Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Huber, ME (reprint author), Univ Colorado, Dept Phys, Denver, CO 80217 USA. RI Huber, Martin/B-3354-2011 NR 22 TC 22 Z9 23 U1 2 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 1251 EP 1256 DI 10.1109/77.919577 PN 1 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HP UT WOS:000168285400294 ER PT J AU Irwin, KD Huber, ME AF Irwin, KD Huber, ME TI SQUID operational amplifier SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE feedback circuits; SQUIDs; superconducting devices ID PARTICLE-DETECTION AB The nonlinear response of Superconducting Quantum Interference Devices (SQUIDs) has limited their usefulness. We describe the SQUID Operational Amplifier, which consists of several stages of SQUIDs with high open-loop current gain. When connected in a negative-feedback configuration by passing some of the output current through a feedback coil connected to the first stage, the response is linearized. rin analog of the semiconductor op-amp, the SQUID op-amp can be used in superconducting equivalents of op-amp circuits such as current amplifiers, current-to-voltage converters, and differentiators. We present experimental results with a x10 current amplifier as well as a 750 Omega current-to-voltage amplifier which can couple directly to a room-temperature amplifier without a transformer or a feedback line. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. Univ Colorado, Dept Phys, Denver, CO 80217 USA. RP Irwin, KD (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80305 USA. RI Huber, Martin/B-3354-2011 NR 8 TC 16 Z9 16 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 1265 EP 1270 DI 10.1109/77.919580 PN 1 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HP UT WOS:000168285400297 ER PT J AU Booth, JC Vale, LR Ono, RH AF Booth, JC Vale, LR Ono, RH TI On-wafer measurements of nonlinear effects in high temperature superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE high-temperature superconductors; microwave devices; nonlinear response AB We present the results of comprehensive on-wafer microwave probe station measurements of the nonlinear properties of coplanar waveguide devices patterned from high-temperature superconductor (HTS) thin films. We introduce a sequence of measurements and analysis that is designed to describe the nonlinear response of microwave devices in increasingly general terms, and that verifies the resulting description with a number of different nonlinear measurements of different patterned devices. We demonstrate the use of this methodology to analyze the nonlinear response of YBa2CU3O7-8 (YBCO) thin films at 76 K, and find that all of our measurements can be satisfactorily explained by a current-dependent penetration depth of the form lambda=lambda (0)[l+(J/J(0))(2)]. The parameter J(0) is a current-density scale that describes the strength of the material nonlinearity, and can be used as a suitable parameter for optimizing film growth techniques. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Booth, JC (reprint author), Natl Inst Stand & Technol, Boulder, CO 80305 USA. NR 12 TC 8 Z9 8 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 1387 EP 1391 DI 10.1109/77.919610 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HP UT WOS:000168285400327 ER PT J AU Goodrich, LF Stauffer, TC AF Goodrich, LF Stauffer, TC TI Hysteresis in transport critical-current measurements of oxide superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE angle; critical current; high temperature superconductors; hysteresis; variable temperature ID POLYCRYSTALLINE YBA2CU3O7; IRREVERSIBILITY; FLUX AB We have investigated hysteresis in transport critical-current (I-c) measurements of Ag-matrix (Bi,Pb)(2)Sr2Ca2Cu3O10-x (Bi-2223) and AgMg-matrix Bi2Sr2CaCu2O8+x (Bi-2212) tapes. I, hysteresis causes measurements with field, angle, and temperature sweeps to be multi-valued. Which value is correct is addressed in the context that the proper sequence of measurement conditions reflects the application conditions. Hysteresis in angle-sweep and temperature-sweep data is related to field-sweep hysteresis. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Goodrich, LF (reprint author), Natl Inst Stand & Technol, Boulder, CO 80305 USA. NR 8 TC 6 Z9 6 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 3234 EP 3237 DI 10.1109/77.919752 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HV UT WOS:000168285900136 ER PT J AU Haugan, T Wong-Ng, W Cook, LP Geyer, RG Brown, HJ Swartzendruber, L Kaduk, J AF Haugan, T Wong-Ng, W Cook, LP Geyer, RG Brown, HJ Swartzendruber, L Kaduk, J TI Development of low cost (Sr,Ca)(3)Al2O6 dielectrics for Bi2Sr2CaCu2O8+delta applications SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE Bi2Sr2CaCu2O8+delta; dielectric constant and loss tangent; (Sr,Ca)(3)Al2O6; tie-line phase equilibrium ID CU-O SYSTEM; CRYOGENIC TEMPERATURES; SINGLE-CRYSTALS; THICK-FILMS; T-C; ALUMINA; SUPERCONDUCTOR; ADDITIONS; AL2O3; POLARIZABILITIES AB Aspects of the development of low-cost (Sr,Ca)(3)Al2O6 dielectrics for Bi2Sr2CaCu2O8+delta superconductor applications were investigated. A tie-line phase equilibrium relationship between Bi2Sr2CaCu2O8+delta and Sr2CaAl2O6 compositions was observed at 860 degreesC. When the Bi-2212 and (Sr,Ca)(3)Al2O6 solid-solution compositions were changed slightly, the tie-line relationship was not preserved, and a new phase was observed to form with composition similar to BiSr1.5Ca0.5Al2Ox. Composites of (0 to 24) volume fraction % Sr2CaAl2O6 + Bi2Sr2CaCu2O8+delta equilibrated at 860 degreesC slightly reduced the T-c (by 2 g to 4 K) and superconducting volume percentage of the 2212 phase. The dielectric properties of (Sr = 1.0 to 2.5) members of solid-solution (Sr,Ca)(3)Al2O6 were measured at 77 K and 297 K in the range of (10 to 11) GHz for cylindrical samples using resonant system methods. The dielectric constant epsilon (r) varied from 9.7 to 13.2, and the loss tangent tan delta was from 3 x 10(-4) to 8 x 10(-4). C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. BP Amoco Chem, Naperville, IL 60566 USA. RP Haugan, T (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 26 TC 2 Z9 2 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 3305 EP 3308 DI 10.1109/77.919769 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HV UT WOS:000168285900153 ER PT J AU Ekin, JW Bray, SL Cheggour, N Clickner, CC Foltyn, SR Arendt, PN Polyanskii, AA Larbalestier, DC McCowan, CN AF Ekin, JW Bray, SL Cheggour, N Clickner, CC Foltyn, SR Arendt, PN Polyanskii, AA Larbalestier, DC McCowan, CN TI Transverse stress and fatigue effects in Y-Ba-Cu-O coated IBAD tapes SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VA DE coated conductors; critical current; electromechanical; IBAD; mechanical; stress; transverse stress ID YBA2CU3O7-DELTA THICK-FILMS; BUFFER LAYERS; CONDUCTORS; FIELD AB Measurements of the effects of static and cyclic (fatigue) transverse stress on the critical current of Ya-Ba-Cu-O coated tapes made by ion-beam-assisted deposition (IBAD) are reported at 76 K in self magnetic field. Ya-Ba-Cu-O films (similar to1 mum thick) on Inconel substrates (100 mum thick) with IBAD buffer layers had critical-current densities J(c) exceeding 1 MA/cm(2) and n values of about 50 (where n is an index of the sharpness of the superconductor-to-normal transition). Under static loads of 100 MPa, the degradation in J(c) was less than 5% (7% at 120 MPa). When subjected to cyclic loading, there was less than 2% additional degradation in J(c) after 2000 fatigue cycles. Microscopic examination of the samples indicates that this limited J(c) degradation may have arisen from longitudinal cracks forming near the edges of the sample after being subjected to these high transverse pressures. This fracture mode would indicate that longitudinal side support from high-yield substrates or epoxy impregnation of magnet structures may provide additional tolerance against degradation in J(c) from transverse stress. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. Los Alamos Natl Lab, Los Alamos, NM USA. Univ Wisconsin, Madison, WI USA. RP Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80305 USA. EM ekin@boulder.nist.gov; cheggour@boulder.nist.gov RI Cheggour, Najib/K-2769-2012; Larbalestier, David/B-2277-2008 OI Cheggour, Najib/0000-0002-0741-3065; Larbalestier, David/0000-0001-7098-7208 NR 16 TC 20 Z9 20 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1051-8223 EI 1558-2515 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 3389 EP 3392 DI 10.1109/77.919790 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HV UT WOS:000168285900174 ER PT J AU Goldfarb, RB Goodrich, LF Pyon, T Gregory, E AF Goldfarb, RB Goodrich, LF Pyon, T Gregory, E TI Suppression of flux jumps in marginally stable niobium-tin superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2000 Applied Superconductivity Conference CY SEP 17-22, 2000 CL VIRGINIA BEACH, VIRGINIA DE AC losses; flux jumps; hysteresis losses; magnetization measurements; niobium-tin superconductors; superconductor stability ID NB3SN AB Niobium-tin superconductor wires with coalesced filaments may have reduced adiabatic stability. Magnetization measurements on such marginally stable conductors exhibit flux jumps, which appear as a sudden decrease in magnetization as the applied field is changed, caused by the unpinning of flux vortices and resistive heat generation. Flux jumps preclude estimation of the hysteresis loss from the area of the magnetization-versus-field loop. Here, we show that flux jumps can be minimized or suppressed during the measurement of hysteresis loss by immersing the specimen in helium liquid instead of helium gas. The better thermal conductivity of the liquid affords additional dynamic stability against flux jumps. This allows one to determine the loss upon field cycling and to calculate an effective filament diameter, often used to gauge losses and the extent of metallurgical interfilament coupling. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. IGC Adv Superconductors, Waterbury, CT 06704 USA. RP Goldfarb, RB (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80305 USA. RI Goldfarb, Ronald/A-5493-2011 OI Goldfarb, Ronald/0000-0002-1942-7974 NR 11 TC 6 Z9 6 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 2001 VL 11 IS 1 BP 3679 EP 3682 DI 10.1109/77.919863 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 425HV UT WOS:000168285900247 ER PT J AU Piepmeier, JR Gasiewski, AJ AF Piepmeier, JR Gasiewski, AJ TI High-resolution passive polarimetric microwave mapping of ocean surface wind vector fields SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID AIRCRAFT K-BAND; BRIGHTNESS TEMPERATURES; SCATTEROMETER DATA; MODEL; RADIOMETERS; WATER; SPEED; SSM/I AB The retrieval of ocean surface wind fields in both one and two dimensions is demonstrated using passive polarimetric microwave imagery obtained from a conical-scanning airborne polarimeter. The retrieval method is based on an empirical geophysical model function (GMF) for ocean surface thermal emission and an adaptive maximum likelihood (ML) wind vector estimator, Data for the GMF were obtained using the polarimetric scanning radiometer/digital (PSR/D) on the NASA P-3 aircraft during the Labrador Sea Deep Convection Experiment in 1997, To develop the GMF, a number of buoy overflights and GPS dropsondes were used, out of which a GMF of 10.7, 18.7, and 37.0 GHz azimuthal harmonics for the first three Stokes parameters was constructed for the SSM/I incident angle of 53.1 degrees. The data show repeatable azimuthal harmonic coefficient amplitudes of similar to2-3 K peak-to-peak, with a 100% increase in harmonic amplitudes as the frequency is increased from 10.7 to 37 GHz. The GMF is consistent with and extends the results of two independent studies of SSM/I data and also provides a model for the third Stokes parameter over wind speeds up to 20 m/s, The aircraft data show that the polarimetric channels are much less susceptible to geophysical noise associated with maritime convection than the first two Stokes parameters. The polarimetric measurement technique used in the PSR/D also demonstrates the viability of digital correlation radiometry for aircraft or satellite measurements of the full Stokes vector. The ML retrieval algorithm incorporates the additional information on wind direction available from multiple looks and polarimetric channels in a straightforward manner and accommodates the reduced SNRs of the first two Stokes parameters in the presence of convection by weighting these channels by their inverse SNR. The Cramer-Rao bound for the retrieval operator is computed using the SNR estimates. Here, the measurement noise is a root-sum-squared combination of both instrument (radiometric) noise and geophysical (cloud and convection) noise. The retrieved wind directions are within 9 degrees of GPS-dropsonde wind-direction measurements, and the standard deviations are similar to2 times the Cramer-Rao bound. The retrieval method illustrates the capability of mapping ocean surface wind fields from either airborne or spaceborne platforms using a two-look technique. C1 Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Piepmeier, JR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 36 TC 80 Z9 93 U1 1 U2 6 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 MAR PY 2001 VL 39 IS 3 BP 606 EP 622 DI 10.1109/36.911118 PG 17 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 413TM UT WOS:000167628100013 ER PT J AU Berning, DW Hefner, AR AF Berning, DW Hefner, AR TI IGBT model validation for soft-switching applications SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT Annual Meeting of the Industry-Applications-Society CY OCT 03-07, 1999 CL PHOENIX, ARIZONA SP Ind Applicat Soc DE circuit simulation; insulated gate bipolar transistor; model validation; power electronics; soft switching; switching energy AB Techniques are described for validating the performance of insulated gate bipolar transistor (IGBT) circuit simulator models for soft-switching circuit conditions, The circuits used for the validation include a soft-switched boost converter similar to that used in power-factor correction, and a new half-bridge testbed that is specially designed to examine the details of IGBT soft-switching waveforms, The new testbed is designed to emulate the soft-switching circuit conditions of actual applications circuits, while allowing the easy change of IGBT operating conditions. The testbed also eliminates the problems of commutating diode noise and IGBT temperature rise found in actual application circuits. Simulations of IGBT models provided in circuit simulator component libraries are compared with measurements obtained using these test circuits for the soft-switching conditions of zero-voltage turn-on, zero-voltage turn-off, or zero-current turn-off. Finally, the results are summarized by comparing the switching energies for the various measurements and simulations presented in this work. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Berning, DW (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. NR 18 TC 7 Z9 7 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD MAR-APR PY 2001 VL 37 IS 2 BP 650 EP 660 DI 10.1109/28.913733 PG 11 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA 417EP UT WOS:000167822700033 ER PT J AU Hefner, AR Singh, R Lai, JS Berning, DW Bouche, S Chapuy, C AF Hefner, AR Singh, R Lai, JS Berning, DW Bouche, S Chapuy, C TI SiC power diodes provide breakthrough performance for a wide range of applications SO IEEE TRANSACTIONS ON POWER ELECTRONICS LA English DT Article DE fast recovery rectifier; merged PiN Schottky diode; PiN diode; reverse recovery; SiC diode; SiC rectifier AB The electrical performance of silicon carbide (SiC) power diodes is evaluated and compared to that of commercially available silicon (Si) diodes in the voltage range from 600 V through 5000 V, The comparisons include the on-state characteristics, the reverse recovery characteristics, and power converter efficiency and electromagnetic interference (EMI), It is shown that a newly. developed 1500-V SiC merged PiN Schottky (MPS) diode has significant performance advantages over Si diodes optimized for various voltages in the range of 600 V through 1500 V, It is also shown that a newly developed 5000 V SiC PiN diode has significant performance advantages over Si diodes optimized for various voltages in the range of 2000 V through 5000 V, In a test case power converter, replacing the best 600 V Si diodes available with the 1500 V SiC MPS diode results in an increase of po,ver supply efficiency from 82% to 88% for switching at 186 kHz, and a reduction in EMI emissions. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. Cree Inc, Durham, NC 27703 USA. Virginia Polytech Inst & State Univ, Ctr Power Elect Syst, Blacksburg, VA 24061 USA. Univ Montpellier 2, Inst Sci & Engn, ISIM, F-34095 Montpellier 5, France. RP Hefner, AR (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. EM david.berning@nist.gov OI Lai, Jihsheng/0000-0003-2315-8460 NR 9 TC 83 Z9 83 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0885-8993 J9 IEEE T POWER ELECTR JI IEEE Trans. Power Electron. PD MAR PY 2001 VL 16 IS 2 BP 273 EP 280 DI 10.1109/63.911152 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 412JM UT WOS:000167551300014 ER PT J AU Ferre-Pikal, ES Aramburo, MCD Walls, FL Lakin, KM AF Ferre-Pikal, ES Aramburo, MCD Walls, FL Lakin, KM TI 1/f frequency noise of 2-GHZ high-Q thin-film sapphire resonators SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article ID ACOUSTIC RESONATORS; OSCILLATORS AB We present experimental results on intrinsic 1/f frequency modulation (FM) noise in high-overtone thin-film sapphire resonators that operate at 2 GHz. The resonators exhibit several high-Q resonant modes approximately 100 kHz apart, which repeat every 13 MHz. A loaded Q of approximately 20000 was estimated from the phase response, The results show that the FM noise of the resonators varied between S-y(10 Hz) = -202 dB relative (rel) to 1/Hz and -210 dB rel to 1/Hz. The equivalent phase modulation (PM) noise of an oscillator using these resonators (assuming a noiseless amplifier) would range from L(10 Hz) = -39 to -47 dBc/Hz. C1 Univ Wyoming, Laramie, WY 82071 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. TFT Technol Inc, Bend, OR 97701 USA. RP Ferre-Pikal, ES (reprint author), Univ Wyoming, Laramie, WY 82071 USA. NR 12 TC 4 Z9 4 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD MAR PY 2001 VL 48 IS 2 BP 506 EP 510 DI 10.1109/58.911733 PG 5 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA 411PJ UT WOS:000167508200017 PM 11370364 ER PT J AU Coffey, HE Erwin, EH AF Coffey, HE Erwin, EH TI When do the geomagnetic aa and Ap indices disagree? SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT Meeting of the International-Union-of-Geodesy-and-Geophysics (IUGG) CY JUL 27-28, 1999 CL UNIV BIRMINGHAM, BIRMINGHAM, ENGLAND SP Int Union Geodesy & Geophys HO UNIV BIRMINGHAM DE Ap and aa indices; solar cycle; geomagnetic cycle AB The next solar and geomagnetic cycle has been predicted using the Ap and the extensive aa index databases (Thompson, Solar Phys. 148 (1993) 383). Current real-time predictions use the Ap index. Though the correlation between the two indices is at the 0.9 level, the aa and Ap index do not always agree, even though the two aa stations are included in the Ap index. We investigate the differences between these indices, looking for trends at different levels of activity, different solar cycle periods, different times of the day, etc. We find a lower correlation during even numbered solar cycles, a higher correlation late in the UT day, and a higher correlation during solar maximum period. Published by Elsevier Science Ltd. C1 NOAA, Natl Geophys Data Ctr, Boulder, CO 80303 USA. RP Coffey, HE (reprint author), NOAA, Natl Geophys Data Ctr, 325 Broadway, Boulder, CO 80303 USA. NR 16 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD MAR PY 2001 VL 63 IS 5 BP 551 EP 556 DI 10.1016/S1364-6826(00)00171-1 PG 6 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 422HV UT WOS:000168113200019 ER PT J AU Hauglustaine, D Emmons, L Newchurch, M Brasseur, G Takao, T Matsubara, K Johnson, J Ridley, B Stith, J Dye, J AF Hauglustaine, D Emmons, L Newchurch, M Brasseur, G Takao, T Matsubara, K Johnson, J Ridley, B Stith, J Dye, J TI On the role of lightning NO(x) in the formation of tropospheric ozone plumes: A global model perspective SO JOURNAL OF ATMOSPHERIC CHEMISTRY LA English DT Article DE atmospheric composition; ozone; lightning emissions ID CHEMICAL-TRANSPORT MODEL; VERTICAL-DISTRIBUTION; TRACE-A; TROPICAL ATLANTIC; SOUTH-ATLANTIC; FIRE EMISSIONS; PACIFIC-OCEAN; WATER-VAPOR; DISTRIBUTIONS; CHEMISTRY AB A series of ozone transects measured each year from 1987 to 1990 over the western Pacific and eastern Indian oceans between mid-November and mid-December shows a prominent ozone maximum reaching 50-80 ppbv between 5 and 10 km in the 20 degrees S-40 degrees S latitude band. This maximum contrasts with ozone mixing ratios lower than 20 ppbv measured at the same altitudes in equatorial regions. Analyses with a global chemical transport model suggest that these elevated ozone values are part of a large-scale tropospheric ozone plume extending from Africa to the western Pacific across the Indian ocean. These plumes occur several months after the peak in biomass burning influence and during a period of high lightning activity in the Southern Hemisphere tropical belt. The composition and geographical extent of these plumes are similar to the ozone layers previously encountered during the biomass burning season in this region. Our model results suggest that production of nitrogen oxides from lightning strokes sustains the NO(x) (= NO + NO(2)) levels and the ozone photochemical production required in the upper troposphere to form these persistent elevated ozone layers emanating from biomass burning regions. C1 CNRS, Serv Aeron, Paris, France. NCAR, Div Atmospher Chem, Boulder, CO USA. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35899 USA. Max Planck Inst Meteorol, Hamburg, Germany. Japan Meteorol Agcy, Tokyo, Japan. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ N Dakota, Grand Forks, ND 58201 USA. RP Hauglustaine, D (reprint author), CNRS, Serv Aeron, Paris, France. RI Emmons, Louisa/R-8922-2016 OI Emmons, Louisa/0000-0003-2325-6212 NR 68 TC 30 Z9 30 U1 0 U2 7 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-7764 J9 J ATMOS CHEM JI J. Atmos. Chem. PD MAR PY 2001 VL 38 IS 3 BP 277 EP 294 DI 10.1023/A:1006452309388 PG 18 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 410JA UT WOS:000167435800002 ER PT J AU Perkins, R Cusco, L Howley, J Laesecke, A Matthes, S Ramires, MLV AF Perkins, R Cusco, L Howley, J Laesecke, A Matthes, S Ramires, MLV TI Thermal conductivities of alternatives to CFC-11 for foam insulation SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID HOT-WIRE METHOD; WIDE-RANGE; REFRIGERANTS; APPARATUS; HCFC-141B; HFC-134A; GASES AB The present work examines the thermal conductivities of several dilute vapors which are potential alternatives to chlorofluorocarbons (CFCs) for cellular-plastic foams. Thermal conductivity data are reported in the vapor phase, from 280 to 340 K, for trichlorofluoromethane (CFC-11), 1,1, 1-trifluoro-2,2-dichloroethane (HCFC-123), l-fluoro-l,l-dichloroethane (HCFC-141b), 1,1,2-trifluoroethane (HFC-143), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1,2,3,3-hexafluoropropane (HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,2,2,3-pentafluoropropane (HFC-245ca), 2-(difluoromethoxy)-1,1,1-trifluoroethane (HFE-245fa1), 2-(trifluoromethoxy)-1,1,1-trifluoroethane (HFE-263fbl), octafluorocyclo-butane (RC318), 1,1,1-trifluoroacetone, and a 75 mol % cyclopentane + 25 mol % pentane mixture. These data were obtained with a transient hot-wire instrument and are estimated to have an uncertainty of +/-2% (2 sigma confidence) at these low densities. C1 NIST, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Perkins, R (reprint author), Univ Lisbon, Fac Ciencias, Ctr Ciencia & Tecnol Mat, Campo Grande,Bloco C1, P-1700 Lisbon, Portugal. OI Perkins, Richard/0000-0002-8526-6742 NR 20 TC 14 Z9 14 U1 0 U2 4 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 MAR-APR PY 2001 VL 46 IS 2 BP 428 EP 432 DI 10.1021/je990337k PG 5 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 413WH UT WOS:000167634200047 ER PT J AU Laesecke, A Hafer, RF Morris, DJ AF Laesecke, A Hafer, RF Morris, DJ TI Saturated-liquid viscosity of ten binary and ternary alternative refrigerant mixtures. Part I: Measurements SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID SURFACE-TENSION; PROPANE; PHASE; R125 AB The saturated-liquid viscosities of 10 binary and ternary refrigerant mixtures composed of difluoromethane (R32), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), and propane (R290) were measured in a sealed gravitational capillary viscometer with a straight vertical capillary from 245 to 345 K or to a maximum vapor pressure of 3 MPa. The maximum uncertainty of the measurements is estimated to be +/-2.8% for the mixtures of R32 + propane. The largest contribution to the total uncertainty is that of the saturated liquid and vapor densities of the mixtures, which had to be estimated. Comparisons with; viscosity data from the literature show agreement within the mutual uncertainty for all but one data set. Similar. agreement is found with predicted viscosities using the extended-corresponding-states model in NIST Standard Reference Database 23(REFPROP), except for the mixtures of the polar fluids R32 rand R134-a with the nonpolar propane. Their viscosity-composition dependences are strongly nonlinear. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Expt Properties Fluids Grp, Boulder, CO 80305 USA. RP Laesecke, A (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Expt Properties Fluids Grp, 325 Broadway, Boulder, CO 80305 USA. NR 17 TC 9 Z9 11 U1 0 U2 2 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 MAR-APR PY 2001 VL 46 IS 2 BP 433 EP 445 DI 10.1021/je000335w PG 13 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 413WH UT WOS:000167634200048 ER PT J AU He, M Yan, XJ Zhou, JJ Xie, GR AF He, M Yan, XJ Zhou, JJ Xie, GR TI Traditional Chinese medicine database and application on the Web SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article AB To study traditional Chinese medicines and exchange related information through the worldwide Web, we developed a traditional Chinese medicine database and a program for searching and displaying data in the database on the Web. In this paper, the traditional Chinese medicine database is briefly introduced; the methods used in developing the program, including ISAPI (Microsoft Internet Server Application Programming Interface), VRML (Virtual Reality Model Language), and JavaScript are described; and three application examples are also given. C1 Chinese Acad Sci, Inst Chem Met, Lab Comp Chem, Beijing 100080, Peoples R China. RP Yan, XJ (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Bldg 2,Room 1022,325 Broadway, Boulder, CO 80305 USA. NR 18 TC 25 Z9 26 U1 0 U2 5 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 MAR-APR PY 2001 VL 41 IS 2 BP 273 EP 277 DI 10.1021/ci0003101 PG 5 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA 416FD UT WOS:000167768900007 PM 11277710 ER PT J AU Mikhin, D AF Mikhin, D TI Energy-conserving and reciprocal solutions for higher-order parabolic equations SO JOURNAL OF COMPUTATIONAL ACOUSTICS LA English DT Article; Proceedings Paper CT Workshop on Shallow Water Acoustic Modeling (SWAM'99) CY SEP, 1999 CL MONTEREY, CA ID APPROXIMATION; ACOUSTICS; CONSERVATION; PROPAGATION; DENSITY; MEDIA AB The energy conservation law and the flow reversal theorem are valid for underwater acoustic fields. In media at rest the theorem transforms into well-known reciprocity principle. The presented parabolic equation (PE) model strictly preserves these important physical properties in the numerical solution. The new PE is obtained from the one-way wave equation by Godin(12) via Pade approximation of the square root operator and generalized to the case of moving media. The PE is range-dependent and explicitly includes range derivatives of the medium parameters. Implicit finite difference scheme solves the PE written in terms of energy flux. Such formalism inherently provides simple and exact energy-conserving boundary condition at vertical Interfaces. The finite-difference operators, the discreet boundary conditions, and the self-starter are derived by discretization of the differential PE. Discreet energy conservation and flow reversal theorem are rigorously proved as mathematical properties of the finite-difference scheme and confirmed by numerical modeling. Numerical solution is shown to be reciprocal with accuracy of 10-12 decimal digits, which is the accuracy of round-off errors. Energy conservation and wide-angle capabilities of the model are illustrated by comparison with two-way normal mode solutions including the ASA benchmark wedge. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Russian Acad Sci, PP Shirshov Oceanol Inst, Moscow, Russia. RP NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. EM dima@rav.sio.rssi.ru NR 30 TC 10 Z9 10 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-396X EI 1793-6489 J9 J COMPUT ACOUST JI J. Comput. Acoust. PD MAR PY 2001 VL 9 IS 1 BP 183 EP 203 DI 10.1142/S0218396X01000450 PG 21 WC Acoustics; Mathematics, Interdisciplinary Applications SC Acoustics; Mathematics GA 434GD UT WOS:000168806000010 ER PT J AU Van Vaerenbergh, S Coriell, SR McFadden, GB AF Van Vaerenbergh, S Coriell, SR McFadden, GB TI Morphological stability of a binary alloy: thermodiffusion and temperature-dependent diffusivity SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE diffusion; morphological stability; solidification ID THERMOTRANSPORT COEFFICIENTS; CRYSTAL-GROWTH; MICROGRAVITY; MELTS AB The effect of a temperature-dependent solute diffusion coefficient on the morphological stability of a binary alloy during directional solidification is treated by a linear stability analysis. The Soret effect (thermodiffusion) is also included in the analysis. Specific calculations are carried out for a tin alloy containing silver for which the diffusion coefficient has a linear dependence on temperature. Although the temperature dependence of the diffusion coefficient has little effect on the critical concentration for the onset of morphological stability, it causes a significant change in the wavelength at the onset of instability. Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Free Univ Brussels, B-1050 Brussels, Belgium. RP McFadden, GB (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8910, Gaithersburg, MD 20899 USA. RI McFadden, Geoffrey/A-7920-2008; Van Vaerenbergh, Stefan/J-8655-2013 OI McFadden, Geoffrey/0000-0001-6723-2103; Van Vaerenbergh, Stefan/0000-0002-6614-0458 NR 24 TC 7 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD MAR PY 2001 VL 223 IS 4 BP 565 EP 572 DI 10.1016/S0022-0248(01)00620-0 PG 8 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 415UA UT WOS:000167740900019 ER PT J AU Shirley, EL Soininen, JA Zhang, GP Carlisle, JA Callcott, TA Ederer, DL Terminello, LJ Perera, RCC AF Shirley, EL Soininen, JA Zhang, GP Carlisle, JA Callcott, TA Ederer, DL Terminello, LJ Perera, RCC TI Modeling final-state interaction effects in inelastic X-ray scattering from solids: resonant and non-resonant SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 8th International Conference on Electronic Spectroscopy and Structure CY AUG 08-12, 2000 CL UNIV CALIF, CLARK KERR CAMPUS, BERKELEY, CALIFORNIA HO UNIV CALIF, CLARK KERR CAMPUS DE cBN; hBN; IXS; MgO; RIXS; X-ray scattering ID NEAR-EDGE STRUCTURE; HEXAGONAL BORON-NITRIDE; AB-INITIO CALCULATION; ELECTRON-HOLE INTERACTION; DYNAMIC STRUCTURE FACTOR; WIDE-GAP INSULATORS; ENERGY-LOSS SPECTRA; BAND-STRUCTURE; VALENCE-BAND; CORE-LEVEL AB We present resonant inelastic X-ray scattering calculations that realistically incorporate intermediate-state electron-core hole interactions and final-state electron-valence hole interactions. Intermediate-state interactions primarily affect the total fluorescence yield, whereas final-state interactions can change the relative strengths of spectral emission features. This is especially true in systems with strong valence-hole exciton effects. We also consider non-resonant excitation of core electrons. This work considers resonant scattering from B Is electrons in cubic boron nitride (cBN) and hexagonal boron nitride (hBN) and non-resonant scattering from Mg and O Is electrons in MgO, and compares theoretical results to experiment. (C) 2001 Elsevier Science B.V; All rights reserved. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Virginia Commonwealth Univ, Richmond, VA 23284 USA. Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Shirley, EL (reprint author), NIST, Opt Technol Div, 100 Bur Dr,Mail Stop 8441, Gaithersburg, MD 20899 USA. NR 48 TC 11 Z9 11 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAR PY 2001 VL 114 BP 939 EP 946 DI 10.1016/S0368-2048(00)00358-3 PG 8 WC Spectroscopy SC Spectroscopy GA 417JW UT WOS:000167832700146 ER PT J AU Powell, CJ Jablonski, A Naumkin, A Kraut-Vass, A Conny, JM Rumble, JR AF Powell, CJ Jablonski, A Naumkin, A Kraut-Vass, A Conny, JM Rumble, JR TI NIST data resources for surface analysis by X-ray photoelectron spectroscopy and Auger electron spectroscopy SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 8th International Conference on Electronic Spectroscopy and Structure CY AUG 08-12, 2000 CL UNIV CALIF, CLARK KERR CAMPUS, BERKELEY, CA HO UNIV CALIF, CLARK KERR CAMPUS DE Auger-electron spectroscopy; databases; electron elastic-scattering cross sections; electron inelastic mean free paths; standard test data; surface analysis; X-ray photoelectron spectroscopy ID MEAN FREE PATHS; PEAK-PARAMETER ERRORS; STANDARD TEST DATA; SCATTERING; RANGE; SHAPE; AES; XPS AB A description is given of data resources that are available from the National Institute of Standards and Technology (NIST) for X-ray photoelectron spectroscopy (XPS) and Anger-electron spectroscopy. NIST currently has three databases available: an XPS Database, an Electron Elastic-Scattering Cross-Section Database, and an Electron Inelastic-Mean-Free-Path Database. NIST also offers Standard Test Data (STD) for XPS, a set of simulated XPS data designed to evaluate algorithms and procedures for detecting, locating, and measuring the intensities of overlapping peaks in a doublet. The XPS database and the XPS-STD are available over the internet. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Polish Acad Sci, Inst Phys Chem, PL-01224 Warsaw, Poland. Russian Acad Sci, AN Nesmeyanov Inst Organoelement Cpds, Moscow 117813, Russia. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM cedric.powell@nist.gov OI Naumkin, Alexander/0000-0001-5696-5723 NR 15 TC 20 Z9 20 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 EI 1873-2526 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAR PY 2001 VL 114 BP 1097 EP 1102 DI 10.1016/S0368-2048(00)00252-8 PG 6 WC Spectroscopy SC Spectroscopy GA 417JW UT WOS:000167832700169 ER PT J AU Powell, CJ Jablonski, A AF Powell, CJ Jablonski, A TI Effects of elastic-electron scattering on measurements of silicon dioxide film thicknesses by X-ray photoelectron spectroscopy SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 8th International Conference on Electronic Spectroscopy and Structure CY AUG 08-12, 2000 CL UNIV CALIF, CLARK KERR CAMPUS, BERKELEY, CALIFORNIA HO UNIV CALIF, CLARK KERR CAMPUS DE effective attenuation length; elastic scattering; film thickness; silicon dioxide; XPS ID MEAN FREE PATHS; ATTENUATION LENGTHS; ESCAPE PROBABILITY; 50-2000-EV RANGE; XPS AB It is now customary for the effects of elastic-electron scattering to be ignored in measurements of the thicknesses of overlayer films by X-ray photoelectron spectroscopy (XPS). It is known, however, that elastic scattering can cause the effective attenuation length (EAL), needed for the thickness measurement, to be different from the corresponding inelastic mean free path (IMFP). We have investigated the effects of elastic-electron scattering in measurements of thicknesses of SiO2 films on Si from XPS measurements with Al and Mg K alpha X-rays. Calculations were made of substrate and oxide Si 2p photoelectron currents for different oxide thicknesses and emission angles using an algorithm based on the transport approximation. This algorithm accounts for the occurrence of elastic scattering along electron trajectories in the solid. The calculations simulated an angle-resolved XPS experiment in which the angle psi between the X-ray source and the analyzer axis was 40 degrees, 54 degrees, or 70 degrees. For each SiO2 thickness and set of measurement conditions, an average EAL was determined from the substrate currents with and without the oxide overlayer. The ratio of the average EAL to the IMFP varied with SiO2 thickness, emission angle alpha, the angle psi; and the X-ray energy. For alpha less than or equal to 65 degrees and for oxide thicknesses such that the substrate current was reduced to not less than 10% of its original value, the mean EAL for this range of thicknesses was between 0.912 and 0.926 of the corresponding IMFP for Mg K alpha X-rays (for the three psi values) and between 0.922 and 0.935 for Al K alpha X-rays. For larger emission angles, the ratio of the mean EAL to the IMFP varied considerably with alpha and psi An EAL value appropriate for the measurement conditions should be chosen for measurements of SiO, thicknesses by XPS. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. Polish Acad Sci, Inst Phys Chem, PL-01224 Warsaw, Poland. RP Powell, CJ (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 14 TC 41 Z9 41 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAR PY 2001 VL 114 BP 1139 EP 1143 DI 10.1016/S0368-2048(00)00254-1 PG 5 WC Spectroscopy SC Spectroscopy GA 417JW UT WOS:000167832700175 ER PT J AU Smith, DA Robertson, DS Milbert, DG AF Smith, DA Robertson, DS Milbert, DG TI Gravitational attraction of local crustal masses in spherical coordinates SO JOURNAL OF GEODESY LA English DT Article DE Helmert gravity anomalies; terrain correction; digital elevation model; geoid AB The gravitational attractions of terrestrial masses and condensed terrestrial masses were modeled in local regions of gravity stations in different ways. These differences in the models included the type of coordinate frame (Cartesian versus spherical), grid spacing (30 vs 3 arcseconds), and the shape of the terrain ("flat-topped" vs "sloped-topped" prisms). The effect of each of these variables is quantified for its overall impact on Helmert gravity anomalies. The combined effect of removing the masses and restoring the condensed masses is also compared to classical terrain corrections for suitability in computing Helmert anomalies. Some detailed conclusions are drawn from these test computations. The effect of the Earth's curvature has both a near-field effect (due to the differences in volume and shape between rectangular and spherical prisms) and a far-field effect (due to physical location of masses below the horizon). The near-field effect can achieve 0.4 mGal in the Rocky mountains, and affect the geoid by up to 7.5 cm. Additionally, the approximation of the terrain by flat-topped prisms (even at fine spacings such as 3 arcseconds) is inappropriate for terrain near the station, where errors of 20 mGal have been computed using 30-arcsecond data. It is concluded that when 30-arcsecond terrain is allowed to have a more curved (bilinear) prism top, its gravitational attraction is a significantly closer approximation of 3-arcsecond terrain, even for the prism surrounding the station, as compared to the case of 30-arcsecond flat-topped prisms. It is suggested that classical terrain corrections, for many reasons, should not be used to compute Helmert anomalies. Considering only the accuracy, and not the speed, of the computations, the following conclusions are drawn: terrain effects computed inside a local "cap" should be done exclusively in spherical coordinates with a 3-arcsecond Digital Elevation Model (DEM) out to 0.2 degrees radius, and then a 30-arcsecond DEM from 0.2 out to 3.5 degrees. In all cases, bilinearly shaped prism tops should be used. C1 NOAA, Natl Geodet Survey, Silver Spring, MD 20910 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Natl Geodet Survey, Boulder, CO 80309 USA. RP Smith, DA (reprint author), NOAA, Natl Geodet Survey, 1315 E W Highway, Silver Spring, MD 20910 USA. NR 23 TC 19 Z9 19 U1 2 U2 6 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0949-7714 J9 J GEODESY JI J. Geodesy PD MAR PY 2001 VL 74 IS 11-12 BP 783 EP 795 DI 10.1007/s001900000142 PG 13 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 427DE UT WOS:000168388900005 ER PT J AU Schmid, C Molinari, RL Garzoli, SL AF Schmid, C Molinari, RL Garzoli, SL TI New observations of the intermediate depth circulation in the tropical Atlantic SO JOURNAL OF MARINE RESEARCH LA English DT Article ID WESTERN SOUTH-ATLANTIC; TOTAL GEOSTROPHIC CIRCULATION; EQUATORIAL ATLANTIC; NORTH-ATLANTIC; FLOW PATTERNS; DEEP JETS; OCEAN; CURRENTS; WATER; TRANSPORTS AB The intermediate depth (around 1000 m) circulation in the interior tropical Atlantic has been described as several narrow flow bands. Due to a lack of data, these currents have previously been poorly resolved in space and time. Recent observations, obtained during the mid-1997 Seward Johnson cruise and from PALACE floats which cover the period Summer 1997 to Spring 2000, allow a more detailed description of the intermediate depth circulation in the tropical Atlantic. The PALACE trajectories display several well defined currents between the equator and 4N at 800 to 1100 m. Two regimes separated by the eastern edge of the Mid-Atlantic Ridge seem to exist at these latitudes. Velocities in the eastern regime are lower than in the western regime and at some latitudes: the zonal flow in the two regimes is going in opposite directions. Farther south, between 4S and 2S, westward velocities of the central South Equatorial Current dominate the circulation. The flow north of 4N and south of 4S is governed by up to several month-long periods of eastward or westward flow, with only weak preferences for either direction. The southern region is characterized by the (meandering) transition between the central South Equatorial Current and the South Equatorial Countercurrent. It has been proposed earlier that these two currents do not extend eastward beyond about 10W, and that the intermediate water follows a cyclonic path east of 10W between about 5S and 25S. This could be interpreted as an intermediate expression of the Angola Gyre. Such a circulation is not found in the present data set. It is also noted that no significant cross-equatorial flow is found in the PALACE data. C1 Univ Miami, Cooperat Inst Marine & Atmospher Studies, Miami, FL 33149 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Schmid, C (reprint author), Univ Miami, Cooperat Inst Marine & Atmospher Studies, Miami, FL 33149 USA. RI Garzoli, Silvia/A-3556-2010; Schmid, Claudia/D-5875-2013 OI Garzoli, Silvia/0000-0003-3553-2253; Schmid, Claudia/0000-0003-2132-4736 NR 25 TC 17 Z9 18 U1 2 U2 2 PU KLINE GEOLOGY LABORATORY PI NEW HAVEN PA YALE UNIV, NEW HAVEN, CT 06520-8109 USA SN 0022-2402 J9 J MAR RES JI J. Mar. Res. PD MAR PY 2001 VL 59 IS 2 BP 281 EP 312 DI 10.1357/002224001762882664 PG 32 WC Oceanography SC Oceanography GA 436ZT UT WOS:000168966300005 ER PT J AU Waworuntu, JM Garzoli, SL Olson, DB AF Waworuntu, JM Garzoli, SL Olson, DB TI Dynamics of the Makassar Strait SO JOURNAL OF MARINE RESEARCH LA English DT Article ID INVERTED ECHO SOUNDERS; BRAZIL-MALVINAS CONFLUENCE; INDONESIAN SEAS; WATER; ATLANTIC; PACIFIC; THERMOCLINE; VARIABILITY; TRANSPORTS; ALTIMETER AB Data collected as part of the Arlindo Project ("Arlindo" is an acronym for Arus Lintas Indonesia, meaning "throughflow" in Bahasa Indonesia) from October 1996 to March 1998 are analyzed to study the characteristics of the flow through the Makassar Strait. Analysis of inverted echo sounders (IES) and bottom pressure data (PIES) combined with TOPEX/POSEIDON satellite-derived sea height anomaly suggest that a minimum of three-layer approximation is necessary to explain the dynamics of the flow in the Makassar Strait. The simple two-layer model used in several studies of the throughflow is rejected based on total incompatibility with the data sets. A three-layer model with significant contributions by the middle layer provides a consistent interpretation of PIES and satellite data. Results are interpreted in the framework of the large-scale circulation. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Waworuntu, JM (reprint author), PT Newmont Nusa Tenggara, Dept Environm, Jalan Pendidikan 64, Mataram 83125, Indonesia. RI Garzoli, Silvia/A-3556-2010; OI Garzoli, Silvia/0000-0003-3553-2253; Olson, Donald/0000-0001-7180-5672 NR 17 TC 5 Z9 5 U1 0 U2 3 PU KLINE GEOLOGY LABORATORY PI NEW HAVEN PA YALE UNIV, NEW HAVEN, CT 06520-8109 USA SN 0022-2402 J9 J MAR RES JI J. Mar. Res. PD MAR PY 2001 VL 59 IS 2 BP 313 EP 325 PG 13 WC Oceanography SC Oceanography GA 436ZT UT WOS:000168966300006 ER PT J AU Stanimirovic, A Balzaretti, NM Feldman, A Graebner, JE AF Stanimirovic, A Balzaretti, NM Feldman, A Graebner, JE TI Thermal conductivity and thermal diffusivity of selected oxide single crystals SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID VAPOR-DEPOSITED DIAMOND; AC CALORIMETRIC METHOD; THIN-FILMS; CVD DIAMOND AB Values for the thermal conductivity kappa and the thermal diffusivity D of four oxide single crystals were obtained. Near room temperature, the values for kappa (W cm(-1) K-1) and D (cm(2) s(-1)) are as follows: LaAlO3, kappa = 0.115, D = 0.0446; NdGaO3, kappa = 0.068, D = 0.0197 for one structural orientation, and kappa = 0.059, D = 0.0195 for an orthogonal orientation; (LaAlO3)(0.3)-SrAl0.5Ta0.5O3, kappa = 0.051, D = 0.0133; and, ScAlMgO4, kappa = 0.062, D = 0.0229. The relative standard uncertainties in these values are +/-10% (1 sigma). These values allowed us to calculate the specific heat of the materials. The thermal conductivity was measured by a dc heated bar method, and the thermal diffusivity was measured by a modification of Angstrom's method. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Nucl Sci Inst Vinca, Belgrade, Yugoslavia. Univ Fed Rio Grande Sul, Inst Fis, Porto Alegre, RS, Brazil. RP Stanimirovic, A (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Balzaretti, Naira/L-3417-2014 OI Balzaretti, Naira/0000-0003-2797-8618 NR 13 TC 4 Z9 4 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAR PY 2001 VL 16 IS 3 BP 678 EP 682 DI 10.1557/JMR.2001.0090 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA 409VW UT WOS:000167407200007 ER PT J AU Marshall, JC AF Marshall, JC TI New optomechanical technique for measuring layer thickness in MEMS processes SO JOURNAL OF MICROELECTROMECHANICAL SYSTEMS LA English DT Article DE integrated microelectromechanical systems (iMEMS); interferometry; microelectromechanical systems (MEMS); multiuser MEMS processes (MUMPs); polysilicon; profilometry; test structures; thickness ID SURFACE AB Dimensional metrology improvements are needed to achieve the fabrication of repeatable devices, This research presents a new optomechanical technique for measuring the thickness of a suspended material in two distinct microelectromechanical system (MEMS) fabrication processes. This technique includes design of test structure, choice of measurement tools, method of measurement, and computation of thickness. Two tools, the stylus profilometer and optical interferometer, are used to take measurements, Non-contact measurements are possible on structures as narrow as 5 mum. Local thickness measurements are achievable with combined standard uncertainty values of less than 10 nm, Benefits of using the new technique include greater likelihood of fabricating repeatable devices and more accurate measurements of material parameters. The proposed technique is also applicable for measuring layers that are thinner and made of materials other than the conventional suspended material used in this research. C1 Natl Inst Stand & Technol, Div Semicond Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. RP Marshall, JC (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. NR 12 TC 6 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1057-7157 EI 1941-0158 J9 J MICROELECTROMECH S JI J. Microelectromech. Syst. PD MAR PY 2001 VL 10 IS 1 BP 153 EP 157 DI 10.1109/84.911104 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation; Physics, Applied SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation; Physics GA 411LR UT WOS:000167502000024 ER PT J AU Scholz, NL de Vente, J Truman, JW Graubard, K AF Scholz, NL de Vente, J Truman, JW Graubard, K TI Neural network partitioning by NO and cGMP SO JOURNAL OF NEUROSCIENCE LA English DT Article DE NO; nitric oxide; cGMP; guanylate cyclase; stomatogastric; plasticity; crustacean; central pattern generator; cross talk ID STOMATOGASTRIC NERVOUS-SYSTEM; SEQUENTIAL DEVELOPMENTAL ACQUISITION; CRAB CANCER-BOREALIS; MILL MOTOR PATTERN; NITRIC-OXIDE; GASTRIC MILL; GUANYLATE-CYCLASE; CYCLIC-AMP; NEURONS; GANGLION AB The stomatogastric ganglion (STG) of the crab Cancer productus contains similar to 30 neurons arrayed into two different networks (gastric mill and pyloric), each of which produces a distinct motor pattern in vitro. Here we show that the functional division of the STG into these two networks requires intact NO-cGMP signaling. Multiple nitric oxide synthase (NOS)-like proteins are expressed in the stomatogastric nervous system, and NO appears to be released as an orthograde transmitter from descending inputs to the STG. The receptor of NO, a soluble guanylate cyclase (sGC), is expressed in a subset of neurons in both motor networks. When NO diffusion or sGC activation are blocked within the ganglion, the two networks combine into a single conjoint circuit. The gastric mill motor rhythm breaks down, and several gastric neurons pattern switch and begin firing in pyloric time. The functional reorganization of the STG is both rapid and reversible, and the gastric mill motor rhythm is restored when the ganglion is returned to normal saline. Finally, pharmacological manipulations of the NO-cGMP pathway are ineffective when descending modulatory inputs to the STG are blocked. This suggests that the NO-cGMP pathway may interact with other biochemical cascades to partition rhythmic motor output from the ganglion. C1 Univ Washington, Dept Zool, Seattle, WA 98195 USA. Univ Maastricht, Dept Psychiat & Neuropsychol, NL-6200 MD Maastricht, Netherlands. RP Scholz, NL (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. RI Scholz, Nathaniel/L-1642-2013 OI Scholz, Nathaniel/0000-0001-6207-0272 FU NINDS NIH HHS [NS13079] NR 54 TC 40 Z9 42 U1 0 U2 1 PU SOC NEUROSCIENCE PI WASHINGTON PA 11 DUPONT CIRCLE, NW, STE 500, WASHINGTON, DC 20036 USA SN 0270-6474 J9 J NEUROSCI JI J. Neurosci. PD MAR 1 PY 2001 VL 21 IS 5 BP 1610 EP 1618 PG 9 WC Neurosciences SC Neurosciences & Neurology GA 404YG UT WOS:000167129700023 PM 11222651 ER PT J AU Christophorou, LG Olthoff, JK AF Christophorou, LG Olthoff, JK TI Electron interactions with c-C4F8 SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE attachment; c-C4F8; coefficients; cross sections; electron interactions; electron transport; ionization; perfluorocyclobutane; scattering ID CYCLOTRON-RESONANCE PLASMA; INFRARED MULTIPHOTON DISSOCIATION; CROSS-SECTIONS; POLYATOMIC-MOLECULES; SILICON DIOXIDE; ATTACHMENT; ENERGY; C4F8; OCTAFLUOROCYCLOBUTANE; PERFLUOROCYCLOBUTANE AB The limited electron collision cross-section and transport-coefficient data for the plasma processing gas perfluorocyclobutane (C-C4F8) are synthesized, assessed, and discussed. These include cross sections for total electron scattering, differential elastic electron scattering, partial and total ionization, dissociation into neutral fragments, and electron attachment, as well as data on electron transport, ionization, and attachment coefficients. The available data on both the electron collision cross sections and the electron transport coefficients require confirmation. Also, measurements are needed of the momentum transfer and elastic integral cross sections, and of the cross sections for other. significant low-energy electron collision processes such as vibrational and electronic excitation. In addition, electron transport data over a wider range of values of the density-reduced electric field are needed. The present assessment of data on electron affinity, attachment, and scattering suggests the existence of negative ion states near - 0.6, 4.9, 6.9, 9.0, and 10.5 eV. (C) 2001 by the U.S. Secretary of Commerce on behalf of the United States. AII rights reserved. C1 Natl Inst Stand & Technol, Elect & Elect Engn Lab, Div Elect, Gaithersburg, MD 20899 USA. RP Christophorou, LG (reprint author), Natl Inst Stand & Technol, Elect & Elect Engn Lab, Div Elect, Gaithersburg, MD 20899 USA. NR 97 TC 48 Z9 49 U1 0 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD MAR-APR PY 2001 VL 30 IS 2 BP 449 EP 473 DI 10.1063/1.1372164 PG 25 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA 454NW UT WOS:000169979500001 ER PT J AU Dorofeeva, O Novikov, VP Neumann, DB AF Dorofeeva, O Novikov, VP Neumann, DB TI NIST-JANAF thermochemical tables. I. Ten organic molecules related to atmospheric chemistry SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Review DE critical evaluation; enthalpy of formation; group additivity method; heat capacity; internal rotation; molecular structure; normal coordinates; spectroscopic properties; thermodynamic properties; transferable force fields ID VALENCE FORCE-FIELD; STRUCTURALLY RELATED MOLECULES; VIBRATION-ROTATIONAL ANALYSES; TORSIONAL POTENTIAL FUNCTION; LASER-INDUCED ROTAMERIZATION; COUPLING-CONSTANT TENSOR; INTERNAL-ROTATION; CIS-GLYOXAL; AB-INITIO; GLYCOLIC ACID AB The structural, spectroscopic, and thermodynamic properties of 10 gas phase organic molecules related to atmospheric chemistry, including three peroxides and four carboxylic acids, are reviewed. The calculation of the thermochemical tables involved the critical evaluation of new spectroscopic data, enthalpy of formation determinations, and the use of recent internal rotation data. Since insufficient information to characterize all 10 molecules exists, estimation schemes were used to provide the missing experimental and theoretical data. (C) 2001 by the U.S. Secretary of Commerce on behalf of the United States. All rights reserved. C1 NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Moscow MV Lomonosov State Univ, Dept Chem, Moscow 119899, Russia. Univ Maryland Baltimore Cty, Dept Chem & Biochem, Baltimore, MD 21250 USA. RP Dorofeeva, O (reprint author), Russian Acad Sci, IVTAN Assoc, Glushko Thermoctr, Izhorskaya St 13-19, Moscow 127412, Russia. RI Dorofeeva, Olga/E-2427-2012 NR 230 TC 25 Z9 25 U1 3 U2 28 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD MAR-APR PY 2001 VL 30 IS 2 BP 475 EP 513 DI 10.1063/1.1364518 PG 39 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA 454NW UT WOS:000169979500002 ER PT J AU Ratner, A Driscoll, JF Huh, H Bryant, RA AF Ratner, A Driscoll, JF Huh, H Bryant, RA TI Combustion efficiencies of supersonic flames SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID LASER-INDUCED FLUORESCENCE; SCRAMJET COMBUSTORS; SHEAR-LAYER; PERFORMANCE; ACETONE; LIMITS; FLOWS AB Measured values of combustion efficiency eta (c), which quantify the amount of hydrogen fuel that remains unburned because the fuel has insufficient residence time in the reaction zone of a supersonic flame, are reported. Trends are reported as the fuel flow rate and the stagnation temperature are systematically varied. The combustion efficiency measurements are needed to assess chemistry submodels of numerical simulations of supersonic flames. A hydrogen jet flume is stabilized on the axis of a Mach 2.5 wind tunnel, and to explain why some fuel remains unburned images were obtained of the fuel concentration and the OH radical concentration using planar laser-induced fluorescence. Increasing the fuel flow rate (and overall fuel-air equivalence ratio from 0.034 to 0.068) is found to increase the combustion efficiency and the flame length. It is believed that the increased residence time of fuel in the longer dames causes the observed increase in efficiency. The increase the combustion efficiency caused by an increase in the stagnation temperature is quantified. Oblique shock waves were added and were found to decrease combustion efficiency if the waves are positioned to create a radial outflow of fuel away from the OH radical zone, which reduces the residence time. C1 Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. Chungnam Natl Univ, Dept Aerosp Engn, Taejon 305764, South Korea. NIST, Gaithersburg, MD 20899 USA. RP Ratner, A (reprint author), Univ Michigan, Dept Aerosp Engn, Bldg 2118, Ann Arbor, MI 48109 USA. NR 23 TC 4 Z9 4 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD MAR-APR PY 2001 VL 17 IS 2 BP 301 EP 307 DI 10.2514/2.5742 PG 7 WC Engineering, Aerospace SC Engineering GA 411TZ UT WOS:000167516500011 ER PT J AU Maslar, JE Hurst, WS Vanderah, TA Levin, I AF Maslar, JE Hurst, WS Vanderah, TA Levin, I TI The Raman spectra of Cr3O8 and Cr2O5 SO JOURNAL OF RAMAN SPECTROSCOPY LA English DT Article ID CHROMIUM; CATALYSTS; DECOMPOSITION; SPECTROSCOPY; CALIBRATION AB The Raman spectra of polycrystalline Cr3O8 and Cr2O5 powders were measured. The powders were prepared by thermal decomposition of CrO3 under flowing oxygen. Their composition was verified with x-ray diffraction. Raman spectra were excited with both 514.5 and 647.1 nm radiation. The spectral intensities were corrected for wavelength-dependent instrumental response. Tentative peak descriptions were made by comparison of the Cr3O8 and Cr2O5 spectra with reported spectra of crystalline chromium oxides. Copyright (C) 2001 John Wiley & Sons, Ltd. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Maslar, JE (reprint author), NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RI Levin, Igor/F-8588-2010 NR 31 TC 29 Z9 29 U1 1 U2 10 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0377-0486 J9 J RAMAN SPECTROSC JI J. Raman Spectrosc. PD MAR PY 2001 VL 32 IS 3 BP 201 EP 206 PG 6 WC Spectroscopy SC Spectroscopy GA 418QE UT WOS:000167902200007 ER PT J AU Phillips, SD Estler, WT Doiron, T Eberhardt, KR Levenson, MS AF Phillips, SD Estler, WT Doiron, T Eberhardt, KR Levenson, MS TI A careful consideration of the calibration concept SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE calibration; error; influence quantities; measurand; systematic error; uncertainty AB This paper presents a detailed discussion of the technical aspects of the calibration process with emphasis on the definition of the measurand, the conditions under which the calibration results are valid, and the subsequent use of the calibration results in measurement uncertainty statements. The concepts of measurement uncertainty, error, systematic error, and reproducibility are also addressed as they pertain to the calibration process. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Phillips, SD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 6 TC 8 Z9 8 U1 0 U2 4 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 2001 VL 106 IS 2 BP 371 EP 379 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435JA UT WOS:000168872700001 PM 27500027 ER PT J AU Gaigalas, AK Li, L Henderson, O Vogt, R Barr, J Marti, G Weaver, J Schwartz, A AF Gaigalas, AK Li, L Henderson, O Vogt, R Barr, J Marti, G Weaver, J Schwartz, A TI The development of fluorescence intensity standards SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE fluorescence intensity; quantitative fluorescence; standards ID FLOW-CYTOMETRY; QUANTITATION AB The use of fluorescence as an analytical technique has been growing over the last 20 years. A major factor in inhibiting more rapid growth has been the inability to make comparable fluorescence intensity measurements across laboratories. NIST recognizes the need to develop and provide primary fluorescence intensity standard (FIS) reference materials to the scientific and technical communities involved in these assays. The critical component of the effort will be the cooperation between the Federal laboratories, the manufacturers, and the technical personnel who will use the fluorescence intensity standards. We realize that the development and use of FIS will have to overcome many difficulties. However, as we outline in this article, the development of FIS is feasible. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Ctr Dis Control, Atlanta, GA 30333 USA. US FDA, Ctr Biol Evaluat & Res, Bethesda, MD USA. US FDA, CDER, Laurel, MD USA. Ctr Quantitat Cytometry, San Juan, PR USA. RP Gaigalas, AK (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 21 TC 35 Z9 36 U1 1 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 MAR-APR PY 2001 VL 106 IS 2 BP 381 EP 389 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435JA UT WOS:000168872700002 PM 27500028 ER PT J AU Ferraris, CF AF Ferraris, CF TI Concrete mixing methods and concrete mixers: State of the art SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE concrete mixers; mixer efficiency AB As for all materials, the performance of concrete is determined by its microstructure. Its microstructure is determined by its composition, its curing conditions, and also by the mixing method and mixer conditions used to process the concrete. This paper gives an overview of the various types of mixing methods and concrete mixers commercially available used by the concrete industry. There are two main types of mixers used: batch mixers and continuous mixers. Batch mixers are the most common. To determine the mixing method best suited for a specific application, factors to be considered include: location of the construction site (distance from the batching plant), the amount of concrete needed, the construction schedule (volume of concrete needed per hour), and the cost. Ultimately, the quality of the concrete produced determines its performance after placement. An important measure of the quality is the homogeneity of the material after mixing. This paper will review mixing methods in regards to the quality of the concrete produced. Some procedures used to determine the effectiveness of the mixing will be examined. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Ferraris, CF (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 15 TC 18 Z9 28 U1 1 U2 7 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 MAR-APR PY 2001 VL 106 IS 2 BP 391 EP 399 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435JA UT WOS:000168872700003 PM 27500029 ER PT J AU Miller, LE AF Miller, LE TI Distribution of link distances in a wireless network SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE link distance; mobile networks; probability distribution; wireless communication; wireless networks AB The probability distribution is found for the link distance between two randomly positioned mobile radios in a wireless network for two representative deployment scenarios: (1) the mobile locations are uniformly distributed over a rectangular area and (2) the x and y coordinates of the mobile locations have Gaussian distributions. It is shown that the shapes of the link distance distributions for these scenarios are very similar when the width of the rectangular area in the first scenario is taken to be about three times the standard deviation of the location distribution in the second scenario. Thus the choice of mobile location distribution is not critical, but can be selected for the convenience of other aspects of the analysis or simulation of the mobile system. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Miller, LE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 5 TC 76 Z9 79 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 MAR-APR PY 2001 VL 106 IS 2 BP 401 EP 412 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435JA UT WOS:000168872700004 PM 27500030 ER PT J AU Lee, YT Soons, JA Donmez, MA AF Lee, YT Soons, JA Donmez, MA TI Information model for machine-tool-performance tests SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE data exchange; EXPRESS language; information model; machine performance test; machine tools; standard for the exchange of product model data AB This report specifies an information model of machine-tool-performance tests in the EXPRESS [1] language. The information model provides a mechanism for describing the properties and results of machine-tool-performance tests. The objective of the information model is a standardized, computer-interpretable representation that allows for efficient archiving and exchange of performance test data throughout the life cycle of the machine. The report also demonstrates the implementation of the information model using three different implementation methods. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Lee, YT (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 20 TC 0 Z9 0 U1 2 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 MAR-APR PY 2001 VL 106 IS 2 BP 413 EP 439 PG 27 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435JA UT WOS:000168872700005 PM 27500031 ER PT J AU Kearsley, AJ AF Kearsley, AJ TI Global and local optimization algorithms for optimal signal set design SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE nonlinear programming; optimization; signal set ID INEQUALITY CONSTRAINED OPTIMIZATION; NON-GAUSSIAN DETECTORS; CONVERGENCE AB The problem of choosing an optimal signal set for non-Gaussian detection was reduced to a smooth inequality constrained mini-max nonlinear programming problem by Gockenbach and Kearsley. Here we consider the application of several optimization algorithms, both global and local, to this problem. The most promising results are obtained when special-purpose sequential quadratic programming (SQP) algorithms are embedded into stochastic global algorithms. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kearsley, AJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 25 TC 7 Z9 7 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 MAR-APR PY 2001 VL 106 IS 2 BP 441 EP 454 PG 14 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435JA UT WOS:000168872700006 PM 27500032 ER PT J AU Gharavi, H Alamouti, SM AF Gharavi, H Alamouti, SM TI Video transmission for third generation wireless communication systems SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE multimedia communications; third generation mobile systems; WCDMA; wireless video AB This paper presents a twin-class unequal protected video transmission system over wireless channels. Video partitioning based on a separation of the Variable Length Coded (VLC) Discrete Cosine Transform (DCT) coefficients within each block is considered for constant bitrate transmission (CBR). In the splitting process the fraction of bits assigned to each of the two partitions is adjusted according to the requirements of the unequal error protection scheme employed. Subsequently, partitioning is applied to the ITU-T H.263 coding standard. As a transport vehicle, we have considered one of the leading third generation cellular radio standards known as WCDMA. A dual-priority transmission system is then invoked on the WCDMA system where the video data, after being broken into two streams, is unequally protected. We use a very simple error correction coding scheme for illustration and then propose more sophisticated forms of unequal protection of the digitized video signals. We show that this strategy results in a significantly higher quality of the reconstructed video data when it is transmitted over time-varying multipath fading channels. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Cadence Design Syst Inc, San Jose, CA 95134 USA. RP Gharavi, H (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 15 TC 9 Z9 9 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 MAR-APR PY 2001 VL 106 IS 2 BP 455 EP 469 PG 15 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435JA UT WOS:000168872700007 PM 27500033 ER PT J AU Migler, KB Lavallee, C Dillon, MP Woods, SS Gettinger, CL AF Migler, KB Lavallee, C Dillon, MP Woods, SS Gettinger, CL TI Visualizing the elimination of sharkskin through fluoropolymer additives: Coating and polymer-polymer slippage SO JOURNAL OF RHEOLOGY LA English DT Article ID HIGH-DENSITY POLYETHYLENE; WALL SLIP; IN-LINE; INTERFACE; EXTRUSION; MELT; BLENDS; FLOW; FLUOROELASTOMER; INSTABILITIES AB We developed a capillary rheo-optics technique to visualize how fluoropolymer polymer processing additives (PPA) eliminate a surface distortion called "sharkskin" in the extrudate of linear low-density polyethylene (LLDPE). The measurements were carried out in a transparent sapphire tube located at the exit of a twin-screw extruder. Depth-resolved optical microscopy was used to measure both the polymer velocity profiles and to image the coating process of the PPA onto the capillary wall. In the absence of PPA, no slippage occurs between the capillary wall and the polyethylene; sharkskin was observed at all flow rates. Upon addition of the PIPA to the LLDPE, the PPA migrates to the capillary wall where it sticks and induces slippage between itself and the LLDPE, concomitant with the elimination of sharkskin. The interface between the PPA and LLDPE is characterized by long stripes in the flow direction. Large values of the polymer-polymer slippage parameter were found which indicate that the fluoropolymer and LLDPE are fully disentangled at their interface. The PPA acts by dramatically reducing the extensional deformation of the LLDPE at the exit surface. (C) 2001 The Society of Rheology. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. 3M Ctr, Display Mat Technol Ctr, St Paul, MN 55144 USA. Dyneon LLC, Oakdale, MN 55128 USA. 3M Canada Co, London, ON N6A 4T1, Canada. RP Migler, KB (reprint author), NIST, Div Polymers, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 37 TC 81 Z9 85 U1 4 U2 20 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0148-6055 J9 J RHEOL JI J. Rheol. PD MAR-APR PY 2001 VL 45 IS 2 BP 565 EP 581 DI 10.1122/1.1349136 PG 17 WC Mechanics SC Mechanics GA 409HK UT WOS:000167378100016 ER PT J AU Bendersky, LA Chen, RJ Fawcett, ID Greenblatt, M AF Bendersky, LA Chen, RJ Fawcett, ID Greenblatt, M TI TEM study of the electron-doped layered La2-2xCa1+2xMn2O7: Orthorhombic phase in the 0.8 < x < 1.0 composition range SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE La2-2xCa1+2xMn2O7; manganates; TEM; crystallography; phase transition ID GIANT MAGNETORESISTANCE; MANGANATES; REFINEMENT AB A series of Ruddlesden-Popper compounds with n = 2 and stoichiometry La2-2xCa1+2xMn2O7 were synthesized by a citrate gel technique and studied by TEM for the composition range 0.8 < x < 1.0. In situ experiments and analysis of substructure/twins identified structural changes of the 14/mmm phase at low temperatures (200-350 degreesC), Reciprocal space analysis identified superlattice reflections (not previously detected by X ray) and possible space groups. The low-temperature phase belongs to the noncentrosymmetric Cmc2(1) or Ama2 space group, and the transient Cmcm space group is also possible. These structural transitions do not coincide with the magnetic transitions, which occur below room temperature. A structural model based on tilting of almost-rigid octahedra is suggested for Cmcm and Cmc2(1). The proposed model for the low-temperature Cmc2(1) phase has a Phi Phi Psi (z)/Phi Phi Psi (z) combination of tilts, while the transient Cmcm has a Phi Phi0/Phi Phi0 combination of tilts. (C) 2001 Academic Press C1 NIST, Div Met, Gaithersburg, MD 20899 USA. Rutgers State Univ, Dept Chem, Piscataway, NJ 08854 USA. RP Bendersky, LA (reprint author), NIST, Div Met, 100 Bur Dr,Stop 8554, Gaithersburg, MD 20899 USA. NR 22 TC 13 Z9 13 U1 1 U2 5 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD MAR PY 2001 VL 157 IS 2 BP 309 EP 323 DI 10.1006/jssc.2000.9068 PG 15 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 416QL UT WOS:000167791600009 ER PT J AU Abdulagatov, IM Magomedov, UB AF Abdulagatov, IM Magomedov, UB TI Thermal conductivity of aqueous KI and KBr solutions at high temperatures and high pressures SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE apparent molar thermal conductivity; aqueous solutions; high pressure; high temperature; potassium bromide; potassium iodide; thermal conductivity; water ID 100 MPA; 473 K; RANGE AB Experimental measurements are reported for the thermal conductivity of H2O + KI and H2O + KBr solutions using a parallel-plate apparatus. The measurements cover the temperature range from 293 to 473 K at pressures to 100 MPa for salt concentrations between 2.5 and 25 wt.%. The accuracy of the measurements was estimated to be +/-1.6%. The data are compared with the experimental and correlation results of other investigators. For a given concentration, the thermal conductivity was found to vary linearly with pressure. The thermal conductivity at low concentrations below 25 wt.% shows a linear dependence on concentration for all isotherms. Each isobar at a given concentration shows a thermal conductivity maximum at temperatures between 405 and 417 K. The apparent molar thermal conductivity values at 293 K for aqueous KI and KBr are calculated from derived experimental data. 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 20 TC 13 Z9 13 U1 0 U2 4 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD MAR PY 2001 VL 30 IS 3 BP 223 EP 235 DI 10.1023/A:1005223415475 PG 13 WC Chemistry, Physical SC Chemistry GA 442BL UT WOS:000169265300003 ER PT J AU Civjan, SA Engelhardt, MD Gross, JL AF Civjan, SA Engelhardt, MD Gross, JL TI Slab effects in SMRF retrofit connection tests SO JOURNAL OF STRUCTURAL ENGINEERING-ASCE LA English DT Article ID MOMENT-RESISTING CONNECTIONS; SEISMIC RESPONSE AB A series of six full-scale subassemblages were tested to investigate dogbone and haunch retrofits for pre-Northridge steel moment connections. Tests included matched pairs of specimens, one bare steel and one including composite slab. Data were collected to evaluate the influence and behavior of the concrete slab. Results that emphasize the influence of the composite slab on connection behavior and specific comments on the slab response are presented. The presence of a composite slab corresponded to higher-achieved overall plastic rotations and higher-peak attained moments. Existing estimates of composite beam capacity overestimated the specimen strengths in positive moment. Shear stud failures were observed, raising concerns about the capacity of shear studs under severe reversed cyclic loading. C1 Univ Massachusetts, Dept Civil & Environm Engn, Amherst, MA 01003 USA. Univ Texas, Phil M Ferguson Struct Engn Lab, Dept Civil Engn, Austin, TX 78758 USA. Natl Inst Stand & Technol, Struct Div, Gaithersburg, MD 20899 USA. RP Civjan, SA (reprint author), Univ Massachusetts, Dept Civil & Environm Engn, 139 Marston Hall,Box 35205, Amherst, MA 01003 USA. RI Gross, Jorge/G-9138-2012 NR 15 TC 13 Z9 13 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9445 J9 J STRUCT ENG-ASCE JI J. Struct. Eng.-ASCE PD MAR PY 2001 VL 127 IS 3 BP 230 EP 237 DI 10.1061/(ASCE)0733-9445(2001)127:3(230) PG 8 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA 405KJ UT WOS:000167158300002 ER PT J AU Rhee, YW Kim, HW Deng, Y Lawn, BR AF Rhee, YW Kim, HW Deng, Y Lawn, BR TI Brittle fracture versus quasi plasticity in ceramics: A simple predictive index SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID HERTZIAN CONTACT DAMAGE; STRESS-STRAIN CURVES; STRENGTH DEGRADATION; CONE CRACKS; MECHANICAL CHARACTERIZATION; POLYCRYSTALLINE CERAMICS; SILICON-NITRIDE; CYCLIC FATIGUE; INDENTATION; TOUGHNESS AB Simple relations for the onset of competing brittle and quasi-plastic damage modes in Hertzian contact are presented. The formulations are expressed in terms of well-documented material parameters, elastic modulus, toughness, and hardness, enabling a priori predictions for given ceramics and indenter radii. Data from a range of selected ceramic land other) materials are used to demonstrate the applicability of the critical load relations, and to evaluate coefficients in these relations. The results confirm that quasi plasticity is highly competitive with fracture in ceramics, over a sphere radius range 1-10 mm, Implications concerning the brittleness of ceramics in the context of indentation size effects are discussed. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Rhee, YW (reprint author), Korea Adv Inst Sci & Technol, Dept Mat Sci & Engn, Taejon 305701, South Korea. NR 52 TC 81 Z9 81 U1 0 U2 14 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 2001 VL 84 IS 3 BP 561 EP 565 PG 5 WC Materials Science, Ceramics SC Materials Science GA 410YN UT WOS:000167468800013 ER PT J AU Widiyatmi, I Hashiguchi, H Fukao, S Yamanaka, MD Ogino, SY Gage, KS Harijono, SWB Diharto, S Djojodihardjo, H AF Widiyatmi, I Hashiguchi, H Fukao, S Yamanaka, MD Ogino, SY Gage, KS Harijono, SWB Diharto, S Djojodihardjo, H TI Examination of 3-6 day disturbances over equatorial Indonesia based on boundary layer radar observations during 1996-1999 at Bukittinggi, Serpong and Biak SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article ID WESTERN PACIFIC; WIND; 107-DEGREES-E; 6-DEGREES-S; CONVECTION; PERIOD; OCEAN; MODE AB Spectral, features of lower tropospheric horizontal wind observed during 1996-1999 by Bukittinggi, Serpong and Biak boundary layer radars show 3-6 day periodicities in zonal and meridional components and longer period zonal wind oscillations. Using bandpass filtering analysis the 3-6 day modes show a westward phase speed of about. 700 km day(-1) and a zonal wavelength of about 3500 km, and propagate through the Indonesian maritime continent when the westerly wind is prevailing at Biak. C1 Kyoto Univ, Radio Sci Ctr Space & Atmosphere, Kyoto 6110011, Japan. Natl Inst Aeronaut & Space, Atmospher Res & Dev Ctr, Bandung, Indonesia. Kobe Univ, Grad Sch Sci & Technol, Kobe, Hyogo 657, Japan. NOAA, Boulder, CO USA. Agcy Assessment & Applicat Technol, Jakarta, Indonesia. Indonesian Meteorol & Geophys Agcy, Jakpus, Indonesia. Natl Inst Aeronaut & Space, Jakarta Timur, Indonesia. Frontier Observat Res Syst Global Change, Minato Ku, Tokyo, Japan. RP Hashiguchi, H (reprint author), Kyoto Univ, Radio Sci Ctr Space & Atmosphere, Kyoto 6110011, Japan. EM hasiguti@kurasc.kyoto-u.sc.jp RI Yamanaka, Manabu/E-5671-2011 NR 18 TC 7 Z9 7 U1 0 U2 1 PU METEOROLOGICAL SOC JAPAN PI TOKYO PA C/O JAPAN METEOROLOGICAL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, 100-0004, JAPAN SN 0026-1165 EI 2186-9057 J9 J METEOROL SOC JPN JI J. Meteorol. Soc. Jpn. PD MAR PY 2001 VL 79 IS 1B BP 317 EP 331 DI 10.2151/jmsj.79.317 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 432QK UT WOS:000168707000005 ER PT J AU Liu, AS Rahmani, A Bryant, G Richter, LJ Stranick, SJ AF Liu, AS Rahmani, A Bryant, G Richter, LJ Stranick, SJ TI Modeling illumination-mode near-field optical microscopy of Au nanoparticles SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID DISCRETE-DIPOLE APPROXIMATION; PHOTONIC CRYSTAL; QUANTUM DOTS; SCATTERING; SPECTROSCOPY; OPTIMIZATION; IMAGES; GRAINS; LIGHT AB We present a theoretical analysis of near-held scanning optical microscopy (NSOM) images of small Au particles made in the illumination mode. We model the metal-coated fiber tip as a thin disk consisting of a glass core and an aluminum coating. An external held locally illuminates the tip core. We solve for the local fields, including interactions between the tip and the Au particles, by use of the coupled dipole method and calculate the optical signal collected in the far field. We also determine the tip field, in the absence of the particle, for various tip sizes with different metal-coating thicknesses. Calculated tip fields and simulated images are compared with those obtained with the Bethe-Bouwkamp model, a commonly used simple model for the tip held. Calculated line scans of the NSOM images of Au particles depend strongly on the tip aperture size and metal-coating thickness. For blunt tips with a thick metal coating and sharp tips with a much thinner coating, our thin-disk model reproduces the key features of measured NSOM images. Line scans calculated with the Bethe-Bouwkamp model cannot describe the tip dependence of the experimental images. Tip fields obtained from the thin-disk model show significant enhancement beneath the metal coating and a broader field distribution perpendicular to the polarization. Tip fields obtained with the Bethe-Bouwkamp model do not show these effects. Differences in the line scans for these two models are correlated to the differences between the tip fields for the two models. These differences occur because only the disk model accounts for a finite metal coating. (C) 2001 Optical Society of America. C1 NIST, Gaithersburg, MD 20899 USA. RP Liu, AS (reprint author), Intel Corp, 350 E Plumeria Dr, San Jose, CA 95134 USA. RI Rahmani, Adel/G-6406-2011; Richter, Lee/N-7730-2016 OI Richter, Lee/0000-0002-9433-3724 NR 26 TC 16 Z9 16 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD MAR PY 2001 VL 18 IS 3 BP 704 EP 716 DI 10.1364/JOSAA.18.000704 PG 13 WC Optics SC Optics GA 405JK UT WOS:000167156100028 ER PT J AU Hong, FL Ye, J Ma, LS Picard, S Borde, CJ Hall, JL AF Hong, FL Ye, J Ma, LS Picard, S Borde, CJ Hall, JL TI Rotation dependence of electric quadrupole hyperfine interaction in the ground state of molecular iodine by high-resolution laser spectroscopy SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID HETERODYNE SATURATION SPECTROSCOPY; B-X SYSTEM; 532 NM; ABSOLUTE FREQUENCY; I-2-STABILIZED ND; YAG LASER; I-127(2); TRANSITION; I-2; STABILIZATION AB Doppler-free high-resolution spectroscopy is applied to molecular iodine at 532 nm by Nd:YAG lasers. The main hyperfine components as well as the crossover lines are measured for R(56)32-0 and P(54)32-0 transitions by heterodyne beating of two I-2-stabilized lasers. The measured hyperfine splittings including both main and crossover lines are fitted to a four-term Hamiltonian, which includes the electric quadrupole, spin-rotation, tensor spin-spin, and scalar spin-spin interactions, with an average deviation of similar to1 kHz. Absolute values of the electric quadrupole hyperfine constants for both the upper and the lower states are obtained. The rotation dependence of the ground-state (v" = 0) electric quadrupole constant eQq" is found to be eQq"(J) = -2452.556(2) - 0.000164(5)J(J + 1) - 0.000000005(2)J(2)(J + 1)(2) MHz. (C) 2001 Optical Society of America. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Ye, Jun/C-3312-2011; Hong, Feng-Lei/N-3098-2014 OI Hong, Feng-Lei/0000-0003-1318-2635 NR 44 TC 28 Z9 28 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 EI 1520-8540 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD MAR PY 2001 VL 18 IS 3 BP 379 EP 387 DI 10.1364/JOSAB.18.000379 PG 9 WC Optics SC Optics GA 409HA UT WOS:000167377300022 ER PT J AU Hiraka, H Endoh, Y Fujita, M Lee, YS Kulda, J Ivanov, A Birgeneau, RJ AF Hiraka, H Endoh, Y Fujita, M Lee, YS Kulda, J Ivanov, A Birgeneau, RJ TI Spin fluctuations in the underdoped High-T-c cuprate La1.93Sr0.07CuO4 SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE La2-xSrxCuO4; inelastic neutron scattering; generalized susceptibility; scaling; incommensurate to commensurate transition ID NEUTRON INELASTIC-SCATTERING; FLOATING-ZONE FURNACE; SUPERCONDUCTING LA1.85SR0.15CUO4; MAGNETIC FLUCTUATIONS; ENERGY-SPECTRUM; LA2-XSRXCUO4; EXCITATIONS; LA2CUO4; DEPENDENCE; DYNAMICS AB We performed magnetic inelastic neutron-scattering experiments on La1.93Sr0.07CuO4 over a wide range of omega and T; 2 less than or equal to omega less than or equal to 44meV and 1.5 less than or equal to T < 300 K. The dynamic susceptibility " (q, omega) of this underdoped high-T-c superconductor (T-c = 17K) is characterized by broad, incommensurate peaks. Here, the incommensurate wavevector delta (omega) is approximately 0.07 reciprocal lattice units at low T and omega. The superconducting phase does not possess an observable gap in the spin excitation spectrum down to at least 2 meV. Scaling behavior is demonstrated for the Q-integrated energy spectrum chi "(omega)(T) with respect to (omega /k(B)T). This scaling establishes a connnection between the magnetic excitations of the compositions on either side of the insulator-superconductor boundary in the La2-xSrxCuO4 phase diagram. We note a possible cross-over from an incommensurate to a commensurate response for omega > 20 meV or T > 300 K. C1 Tohoku Univ, Mat Res Inst, Sendai, Miyagi 9808577, Japan. JST, Core Res Evolut Sci & Technol, Kawaguchi 3320012, Japan. Kyoto Univ, Chem Res Inst, Uji, Kyoto 6110011, Japan. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. RP Hiraka, H (reprint author), Tohoku Univ, Mat Res Inst, Sendai, Miyagi 9808577, Japan. RI Fujita, Masaki/D-8430-2013; Kulda, Jiri/G-8667-2016 OI Kulda, Jiri/0000-0002-0570-0570 NR 28 TC 32 Z9 33 U1 0 U2 7 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD MAR PY 2001 VL 70 IS 3 BP 853 EP 858 DI 10.1143/JPSJ.70.853 PG 6 WC Physics, Multidisciplinary SC Physics GA 417KD UT WOS:000167833400040 ER PT J AU Rathbone, CK Babbitt, JK Dong, FM Hardy, RW AF Rathbone, CK Babbitt, JK Dong, FM Hardy, RW TI Performance of juvenile coho salmon Oncorhynchus kisutch fed diets containing meals from fish wastes, deboned fish wastes, or skin-and-bone by-product as the protein ingredient SO JOURNAL OF THE WORLD AQUACULTURE SOCIETY LA English DT Article ID FEEDS AB The suitability of meals derived from fish processing wastes as the protein fraction in practical diets for hatchery-reared coho salmon was investigated. The study compared the performance of coho salmon fed diets containing three products: a skin-and-bone meat (SB), a deboned meal (DR I), and a whole-fish meal (WM) made directly from the fish wastes. A commercial trout diet (CO) was fed to a fourth treatment group. Diets were fed at 3% of body weight per day to juvenile coho salmon for 12 wk, Survival (> 94%) was not significantly different among treatment groups, Average fish weight, feed conversion ratio, whole body proximate and mineral composition, and protein and phosphorus retention were compared. There were no significant differences after 12 wk of feeding in fish weight between WM, DM, and CO, but SD had significantly lower weight and whole body lipid, and significantly higher ash, Compared to WM, DM had a significantly lower feed conversion ratio and higher retention of protein and phosphorus, but these indices were not significantly different from CO. It is concluded that DM is a potentially superior protein ingredient compared to WM, while specific characteristics of SE will limit its use as a protein source in feeds for salmonids, However, SE may prove to be a suitable mineral supplement when added at a low level. Utilization of fish processing wastes in salmonid diets could be a commercially viable alternative to direct disposal of processing wastes. C1 NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Kodiak Lab, Kodiak, AK 99615 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. Univ Washington, Sch Aquat & Fishery Sci, Seattle, WA 98105 USA. Univ Idaho, Hagerman Fish Culture Expt Stn, Hagerman, ID 83332 USA. RP Babbitt, JK (reprint author), NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Kodiak Lab, 118 Trident Way, Kodiak, AK 99615 USA. NR 20 TC 18 Z9 19 U1 1 U2 3 PU WORLD AQUACULTURE SOCIETY PI BATON ROUGE PA LOUISIANA STATE UNIV, 143 J M PARKER COLISEUM, BATON ROUGE, LA 70803 USA SN 0893-8849 J9 J WORLD AQUACULT SOC JI J. World Aquacult. Soc. PD MAR PY 2001 VL 32 IS 1 BP 21 EP 29 DI 10.1111/j.1749-7345.2001.tb00918.x PG 9 WC Fisheries SC Fisheries GA 415LR UT WOS:000167723500003 ER PT J AU Gillen, G King, L Freibaum, B Lareau, R Bennett, J Chmara, F AF Gillen, G King, L Freibaum, B Lareau, R Bennett, J Chmara, F TI Negative cesium sputter ion source for generating cluster primary ion beams for secondary ion mass spectrometry analysis SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID SF5+; INSTRUMENT; EMISSION AB A cesium sputter ion source has been used to generate novel cluster and monoatomic primary ion beams for secondary ion mass spectrometry (SIMS). The source produces a variety of primary ion beam species with sufficient flux to be usable for both organic surface analysis and semiconductor depth profiling. The primary focus of this work is on the generation and use of carbon and carbon-containing cluster primary ion beams for SIMS. Stability of the sputter ion source is a few percent over 20 min, has useful lifetimes of weeks to months, and produces total primary ion beam currents for C-2(-) ions, measured at the sample, of >1 muA at an extraction voltage of 10 kV. Larger cluster ions (C(x)(-)x = 4 - 10 and CsC(x)(-)x = 2 - 8) are produced with tens of nA of beam current. Due to the divergence of the source, focused beam operation gives current densities under optimal conditions of 0.4-0.5 mA/cm(2). Cluster bombardment studies of organic films using carbon clusters C(x)(-)x = 1 - 10 indicate-that large enhancements (up to a factor of 800) in the secondary ion yield for characteristic molecular ions from organic samples can be obtained with the larger cluster ions. The signal enhancement can also be utilized in microfocus operation of the source for organic secondary ion imaging studies. For favorable organic samples, cluster bombardment with C-x(-), x > 6 shows little evidence of degradation of the sample from the accumulation of primary beam-induced damage. This effect can be potentially utilized for depth profiling of organic thin films and for further enhancements in sensitivity for organic SIMS analysis. Depth profiling of low energy As implants in silicon with the CsC6- primary ion demonstrates that as much as a factor of 6 improvement in apparent depth resolution can be obtained compared to profiles obtained under standard conditions using Cs+ bombardment. The flexibility of the source to produce monoatomic primary ion beams from virtually any target material is also being exploited to prepare low energy in situ ion implant standards for quantitative SIMS analysis. (C) 2001 American Vacuum Society. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Fed Aviat Adm, Atlantic City, NJ 08405 USA. SEMATECH, Austin, TX 78741 USA. Peabody Sci, Peabody, MA 01960 USA. RP Gillen, G (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 19 TC 48 Z9 48 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAR-APR PY 2001 VL 19 IS 2 BP 568 EP 575 DI 10.1116/1.1340651 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 413CD UT WOS:000167591600027 ER PT J AU Budd, JW Drummer, TD Nalepa, TF Fahnenstiel, GL AF Budd, JW Drummer, TD Nalepa, TF Fahnenstiel, GL TI Remote sensing of biotic effects: Zebra mussels (Dreissena polymorpha) influence on water clarity in Saginaw Bay, Lake Huron SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID HIGH-RESOLUTION RADIOMETER; LAURENTIAN GREAT-LAKES; COLONIZATION; DYNAMICS AB In this study, Advanced Very High Resolution Radiometer (AVHRR) remote sensing reflectance (R(rs)), imagery from 1987-1993 is used to study changes in water clarity before and after zebra mussels (Dreissena polymorpha) were discovered in Saginaw Bay, Lake Huron. Spatial and temporal trends in the data indicate distinct and persistent increases in water clarity in the inner bay after the first large recruitment of zebra mussels in the fall of 1991. The pre-Dreissena imagery show that turbidity in the inner bay was influenced by the Saginaw River discharge in spring, biological production (plankton) in summer, and wind-driven resuspension in fall, with highest turbidity in spring and fall. Spatial patterns in the post-Dreissena images were more similar regardless of season, with low reflectances in the shallow regions of the inner bay where zebra mussel densities were highest. A regression model based on point data from 24 sampling stations over the 7-yr period indicates that reflectances varied significantly by site and zebra mussel densities, as well as seasonally. Trends in observed and predicted values of reflectances followed similar patterns at each station-highest values were found during 1991 and lowest during 1992 at all stations, with slightly higher R(rs) in 1993 compared to 1992. Whereas AVHRR R(rs) highlight the value of historical imagery for reconstructing seasonal and interannual turbidity patterns in near-shore waters, a new generation of operational ocean color satellites, such as SeaWiFS (Sea-viewing Wide Field-of-view Sensor) and the newly launched MODIS (moderate resolution imaging spectroradiometer), now provide for routine monitoring of important biological and physical processes from space. C1 Michigan Technol Univ, Dept Geol Engn & Sci, Houghton, MI 49931 USA. Michigan Technol Univ, Dept Math Sci, Houghton, MI 49931 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. NOAA, Great Lakes Environm Res Lab, Lake Michigan Field Stn, Muskegon, MI 49441 USA. RP Budd, JW (reprint author), Michigan Technol Univ, Dept Geol Engn & Sci, 1400 Townsend Dr, Houghton, MI 49931 USA. NR 29 TC 48 Z9 48 U1 1 U2 15 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 MAR PY 2001 VL 46 IS 2 BP 213 EP 223 PG 11 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 417DJ UT WOS:000167819900001 ER PT J AU VanLandingham, MR Villarrubia, JS Guthrie, WF Meyers, GF AF VanLandingham, MR Villarrubia, JS Guthrie, WF Meyers, GF TI Nanoindentation of polymers: An overview SO MACROMOLECULAR SYMPOSIA LA English DT Article ID ATOMIC-FORCE MICROSCOPE; MECHANICAL-PROPERTIES; NANOMECHANICAL PROPERTIES; NANOSCALE INDENTATION; ELASTIC PROPERTIES; NANO-INDENTATION; FILMS; SURFACES; SYSTEMS; AFM AB In this paper, the application of instrumented indentation devices to the measurement of the elastic modulus of polymeric materials is reviewed. This review includes a summary of traditional analyses of load-penetration data and a discussion of associated uncertainties. Also, the use of scanning probe microscopes to measure the nanoscale mechanical response of polymers is discussed, particularly with regard to the associated limitations. The application of these methods to polymers often leads to measurements of elastic modulus that are somewhat high relative to bulk measurements with potentially artificial trends in modulus as a function of penetration depth. Also, power law fits to indentation unloading curves are often a poor representation of the actual data, and the power law exponents tend to fall outside the theoretical range. These problems are likely caused by viscoelasticity, the effects of which have only been studied recently. Advancement of nanoindentation testing toward quantitative characterization of polymer properties will require material-independent calibration procedures, polymer reference materials, advances in instrumentation, and new testing and analysis procedures that account for viscoelastic and viscoplastic polymer behavior. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Dow Chem Co USA, Analyt Sci, Midland, MI 48667 USA. RP Natl Inst Stand & Technol, 100 Bur Dr, Gaithersburg, MD 20899 USA. RI Villarrubia, John/C-3459-2013 NR 46 TC 280 Z9 281 U1 15 U2 136 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 101161, 69451 WEINHEIM, GERMANY SN 1022-1360 EI 1521-3900 J9 MACROMOL SYMP JI Macromol. Symp. PD MAR PY 2001 VL 167 BP 15 EP 43 DI 10.1002/1521-3900(200103)167:1<15::AID-MASY15>3.0.CO;2-T PG 29 WC Polymer Science SC Polymer Science GA 430AG UT WOS:000168550600003 ER PT J AU Ferreiro, V Douglas, JF Amis, EJ Karim, A AF Ferreiro, V Douglas, JF Amis, EJ Karim, A TI Phase ordering in blend films of semi-crystalline and amorphous polymers SO MACROMOLECULAR SYMPOSIA LA English DT Article ID POLY(ETHYLENE OXIDE); POLY(METHYL METHACRYLATE); THIN-FILMS; SURFACE-COMPOSITION; BEHAVIOR; SYSTEM AB A combination of optical and atomic force microscopy (AFM) is used for probing changes in the morphology of polymer blend films that accompany phase ordering processes (phase separation and crystallization), The phase separation morphology of a "model" semi-crystalline (polyethyleneoxide or PEG) and amorphous (polymethylmethacrylate or PMMA) polymer blend film is compared to previous observations on binary amorphous polymer blend films of polystyrene (PS) and polyvinylmethylether (PVME). The phase separation patterns are found to be similar except that crystallization of the film at high PEO concentrations obscures the observation of phase separation. The influence of film defects (e.g., scratches) and clay filler particles on the structure of the semi-crystalline and amorphous polymer films is also investigated. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Ferreiro, V (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 27 TC 30 Z9 30 U1 1 U2 10 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 1022-1360 J9 MACROMOL SYMP JI Macromol. Symp. PD MAR PY 2001 VL 167 BP 73 EP 88 DI 10.1002/1521-3900(200103)167:1<73::AID-MASY73>3.0.CO;2-T PG 16 WC Polymer Science SC Polymer Science GA 430AG UT WOS:000168550600006 ER PT J AU Raghavan, D Gu, X VanLandingham, M Nguyen, T AF Raghavan, D Gu, X VanLandingham, M Nguyen, T TI Mapping chemically heterogeneous polymer system using selective chemical reaction and tapping mode atomic force microscopy SO MACROMOLECULAR SYMPOSIA LA English DT Article ID BLOCK-COPOLYMERS; MORPHOLOGY; MIXTURES; BLENDS; FILMS; AFM AB The mapping of chemically heterogeneous regions in PEA/PS film was achieved by reacting the film in a low pH environment and analyzing; by AFM. In 70:30 blend, the domains were identified as PS rich regions and matrix as the PEA rich regions, based on AFM images, FTIR measurements, and chemical modification study. During the course of hydrolysis of PEA, pits were formed in isolated regions of the matrix, as characterized by AFM. C1 Howard Univ, Dept Chem, Polymer Sci Div, Washington, DC 20059 USA. Natl Inst Stand & Technol, Bldg & Fire Res Lab, Bldg Mat Div, Gaithersburg, MD 20899 USA. RP Raghavan, D (reprint author), Howard Univ, Dept Chem, Polymer Sci Div, Washington, DC 20059 USA. NR 13 TC 4 Z9 4 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 1022-1360 J9 MACROMOL SYMP JI Macromol. Symp. PD MAR PY 2001 VL 167 BP 297 EP 305 DI 10.1002/1521-3900(200103)167:1<297::AID-MASY297>3.0.CO;2-2 PG 9 WC Polymer Science SC Polymer Science GA 430AG UT WOS:000168550600022 ER PT J AU Ross, SW Sulak, KJ Munroe, TA AF Ross, SW Sulak, KJ Munroe, TA TI Association of Syscenus infelix (Crustacea : Isopoda : Aegidae) with benthopelagic rattail fishes, Nezumia spp. (Macrouridae), along the western North Atlantic continental slope SO MARINE BIOLOGY LA English DT Article ID FAUNA AB During submersible surveys along the continental slope (summers of 1991 and 1992, 184-847 m) between False Cape, Virginia, and Cape Hatteras, North Carolina, USA, we observed the aegid isopod, Syscenus infelix Harger, attached to the macrourid Nezumia bairdii (Goode and Bean). This is the first report of S. infelix attached to fishes in the western North Atlantic. The association of this blind isopod with its host appears species specific. The large, conspicuous isopod always attached to a fish in the same location, the dorsal midline, immediately behind the first dorsal fin. Attachment appears to be long term, with the isopod forming a characteristic scar consisting of a distinct discolored oval depression with seven small, dark impressions that coalesce as the fish grows. Only one S. infelix was found on each host fish. The isopod occurred on 23.7% of N. bairdii observed from submersible on the middle continental slope off Virginia and North Carolina, compared with 16.6% of 1236 museum specimens of the same species (based on inspection for scars) collected at latitudes 26 degrees -64 degreesN. Prevalence of the fish-isopod association was not correlated with depth or latitude. We also found identical scars on preserved specimens of N, aequalis (2.6% of 660 specimens), N. sclerorhynchus (1.2% of 86 specimens), and N. suilla (14.3% of 7 specimens), mostly from areas outside the range of N. bairdii. No scars were found on museum specimens of N. atlantica (n = 27), N. cyrano (n = 57), or N. longebarbata (n = 7). The low incidence of isopod attachment on these species suggests that N. bairdii is the preferred host. Infestation by the isopod appears to result in erosion of host fish scales and tissue. We propose that S. infelix is an obligate associate of its host fish and should be considered parasitic. C1 N Carolina Natl Estuarine Res Reserve, Wilmington, NC 28409 USA. US Geol Survey, Biol Resources Div, Florida Caribbean Sci Ctr, Gainesville, FL 32653 USA. Natl Museum Nat Hist, Natl Marine Fisheries Serv, Natl Systemat Lab, Washington, DC 20560 USA. RP Ross, SW (reprint author), N Carolina Natl Estuarine Res Reserve, 1 Marvin Moss Ln, Wilmington, NC 28409 USA. NR 30 TC 9 Z9 11 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD MAR PY 2001 VL 138 IS 3 BP 595 EP 601 DI 10.1007/s002270000485 PG 7 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 417MG UT WOS:000167838300016 ER PT J AU Meador, JP Rice, CA AF Meador, JP Rice, CA TI Impaired growth in the polychaete Armandia brevis exposed to tributyltin in sediment SO MARINE ENVIRONMENTAL RESEARCH LA English DT Article DE tributyltin; growth; polychaete; tissue residue; sediment; bioaccumulation; metabolites; toxicity ID GENERALIZED LINEAR-MODELS; NEANTHES-ARENACEODENTATA; INFAUNAL INVERTEBRATES; ACUTE TOXICITY; PUGET SOUND; REPRODUCTION; BUTYLTINS; BIOAVAILABILITY; BIOACCUMULATION; HYDROCARBONS AB Juveniles of the opheliid polychaete, Armandia brevis, were exposed to sediment-associated tributyltin (TBT) for 42 days to evaluate toxicity and bioaccumulation. Growth in this species was inhibited in a dose-response fashion by increasing concentrations of TBT. Even though the biota sediment accumulation factor (BSAF) for TBT declined for the higher sediment concentrations, the total butyltins in tissue increased over all sediment concentrations. At the highest sediment concentrations, polychaetes bioaccumulated less TBT than expected, which was most likely due to reduced uptake and continued metabolism of the parent compound. The less than expected BSAF values exhibited by animals at the exposure concentrations causing severe effects are an important finding for assessing responses in the field. It appears that severe biological effects can occur in long-term experiments without the expected high tissue concentrations; an observation likely explained by altered toxicokinetics. Analysis of variance determined the lowest observed effect concentration for growth to be 191 ng/g sediment dry wt. for 21 days of exposure and 101 ng/g sediment dry wt, at day 42, indicating that 21 days was insufficient for delineating the steady-state toxicity response. When based on regression analysis, the sediment concentration causing a 25% inhibition in growth at 42 days exposure was 93 ng/g dry wt. (total organic carbon = 0.58%). A dose-response association was also determined for polychaete net weight and TBT in tissue. The tissue residue associated with a 25% reduction in growth was 2834 ng/g dry wt. at day 42. A comparison of these results with previous work indicates that juveniles are approximately three times more sensitive than adults to TBT exposure. The sediment concentrations affecting growth in this species are commonly found in urban waterways indicating potentially severe impacts for this and other sensitive species. Published by Elsevier Science Ltd. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Meador, JP (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 23 Z9 27 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0141-1136 J9 MAR ENVIRON RES JI Mar. Environ. Res. PD MAR PY 2001 VL 51 IS 2 BP 113 EP 129 DI 10.1016/S0141-1136(00)00033-7 PG 17 WC Environmental Sciences; Marine & Freshwater Biology; Toxicology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Toxicology GA 389LX UT WOS:000166240300002 PM 11468812 ER PT J AU Carls, MG Babcock, MM Harris, PM Irvine, GV Cusick, JA Rice, SD AF Carls, MG Babcock, MM Harris, PM Irvine, GV Cusick, JA Rice, SD TI Persistence of oiling in mussel beds after the Exxon Valdez oil spill SO MARINE ENVIRONMENTAL RESEARCH LA English DT Article DE mussels; Mytilus trossulus; Prince William Sound; Gulf of Alaska; Exxon Valdez; petroleum hydrocarbons; oil spills; monitoring ID PRINCE-WILLIAM-SOUND; WEATHERED CRUDE-OIL; AROMATIC-COMPOUNDS; FISH EMBRYOS; SEDIMENTS; HYDROCARBONS; EXPOSURE; SENSITIVITY; MORTALITY; MAMMALS AB Persistence and weathering of Exxon Valdez oil in intertidal mussel (Mytilus trossulus) beds in Prince William Sound (PWS) and along the Gulf of Alaska was monitored from 1992 to 1995. Beds with significant contamination included most previously oiled areas in PWS, particularly within the Knight Island group and the Kenai Peninsula. In sediments, yearly mean concentrations of total petroleum hydrocarbons ranged from < 60 g/g in reference beds to 62,258 mug/g wet wt., or approximately 0 to 523 mug/g dry wt. total polynuclear aromatic hydrocarbons (TPAHs). In mussels, mean TPAH concentrations ranged up to 8.1 mug/g dry wt. Hydrocarbon concentrations declined significantly with time in some, but not all mussels and sediments, and should reach background levels within three decades of the spill in most beds. In 1995, mean hydrocarbon concentration was greater than twice background concentration in sediments from 27 of 34 sites, and in mussels from 18 of 31 sites. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. Natl Biol Serv, Alaska Sci Ctr, Anchorage, AK 99503 USA. Natl Pk Serv, Anchorage, AK 99503 USA. RP Carls, MG (reprint author), Natl Marine Fisheries Serv, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 32 TC 65 Z9 68 U1 1 U2 17 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0141-1136 J9 MAR ENVIRON RES JI Mar. Environ. Res. PD MAR PY 2001 VL 51 IS 2 BP 167 EP 190 DI 10.1016/S0141-1136(00)00103-3 PG 24 WC Environmental Sciences; Marine & Freshwater Biology; Toxicology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Toxicology GA 389LX UT WOS:000166240300005 PM 11468815 ER PT J AU Basta, DJ Murphy, MT AF Basta, DJ Murphy, MT TI Fostering sanctuary-aquarium partnerships to promote marine conservation - A commentary from the National Marine Sanctuary System SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Editorial Material C1 NOAA, Off Natl Marine Sanctuaries, Silver Spring, MD 20910 USA. RP Basta, DJ (reprint author), NOAA, Off Natl Marine Sanctuaries, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 USA SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SPR PY 2001 VL 35 IS 1 BP 86 EP 88 PG 3 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 435EG UT WOS:000168864000012 ER PT J AU Phan, LT Lawson, JR Davis, FL AF Phan, LT Lawson, JR Davis, FL TI Effects of elevated temperature exposure on heating characteristics, spalling, and residual properties of high performance concrete SO MATERIALS AND STRUCTURES LA English DT Article AB This paper describes results of NIST's experimental program that focuses on effects of elevated temperature exposure on residual mechanical properties of HPC. Residual mechanical properties were measured by heating the 102 x 204 mm cylinders to steady state thermal conditions at a target temperature, and loading them to failure after the specimens had cooled to room temperature. The test specimens were made of four HPC mixtures with water-to-cementitious material ratio (w/cm) ranging from 0.22 to 0.57, and room-temperature compressive strength at testing ranges from 51 MPa to 93 MPa. Two of the four HPC mixtures contained silica fume. The specimens were heated to a maximum core temperature of 450 degreesC, at a heating rate of 5 degreesC/min. Experimental results indicate that HPCs with higher original strength (lower w/cm) and with silica fume retain more residual strength after elevated temperature exposure than those with lower original strength (higher w/cm) and without silica fume. The differences in modulus of elasticity are less significant. However, the potential for explosive spalling increased in HPC specimens with lower w/cm and silica fume. An examination of the specimens' heating characteristics indicate that the HPC mixtures which experienced explosive spalling had a more restrictive process of capillary pore and chemically bound water loss than those which did not experience spalling. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Struct Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Bldg & Fire Res Lab, Fire Safety Engn Div, Gaithersburg, MD 20899 USA. RP Phan, LT (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Struct Div, MailStop 8611, Gaithersburg, MD 20899 USA. NR 14 TC 74 Z9 80 U1 0 U2 13 PU R I L E M PUBLICATIONS PI CACHAN PA 61 AVE PRESIDENT WILSON, 94235 CACHAN, FRANCE SN 1359-5997 J9 MATER STRUCT JI Mater. Struct. PD MAR PY 2001 VL 34 IS 236 BP 83 EP 91 DI 10.1007/BF02481556 PG 9 WC Construction & Building Technology; Engineering, Civil; Materials Science, Multidisciplinary SC Construction & Building Technology; Engineering; Materials Science GA 427FJ UT WOS:000168393900004 ER PT J AU Leisk, GG Wender, PJ Mitton, DB Latanision, RM AF Leisk, GG Wender, PJ Mitton, DB Latanision, RM TI Aerospace gerontology: Retained austenite as an aging mechanism in duplex bearings SO MATERIALS TECHNOLOGY LA English DT Review AB Due to economic constraints on new product development in many industries, increasing importance is being placed on safely extending the service lives of existing components and systems, often beyond their original design lives. Such extended service, however, can lead to the emergence of unanticipated aging problems. This paper highlights three approaches for equipment gerontology that can help identify such aging problems in an orderly way. The first, a spares-based approach, involves an expert review of all components, comparison of inventory size with use rate, and identification of parts of highest concern for further inquiry. The second, a performance-based approach, establishes an evaluative effort that examines field data and special engineering tests to identify performance shifts that give early indication of impending end-of-life. The third, an analytical approach, is a conceptual ideal for aging management in which future equipment reliability is predicted based on design, materials and use environment. The implementation of an analysis approach for the aging management of a particular strategic guidance system component is described in the form of a detailed case study; specifically, the potential role of retained austenite as an aging mechanism in an accelerometer duplex bearing. C1 MIT, HH Uhlig Corros Lab, Cambridge, MA 02139 USA. Charles Stark Draper Lab Inc, Cambridge, MA 02139 USA. RP Leisk, GG (reprint author), Natl Inst Stand & Technol, Mfg Metrol Div, 100 Bur Dr,Stop 8221, Gaithersburg, MD 20899 USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU MATRICE TECHNOLOGY LIMITED PI POULTON PA PO BOX 41, POULTON FY6 8GD, ENGLAND SN 1066-7857 J9 MATER TECHNOL JI Mater. Technol. PD MAR PY 2001 VL 16 IS 1 BP 36 EP 44 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 499PY UT WOS:000172580600008 ER EF