FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Zimmerman, BE Karam, LR AF Zimmerman, BE Karam, LR TI Synthesis and characterization of liposome-encapsulated Technetium-99m for use in intravascular brachytherapy. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 973 BP 219P EP 219P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300872 ER PT J AU Hunter, EPL Lias, SG AF Hunter, EPL Lias, SG TI Evaluated gas phase basicities and proton affinities of molecules: An update SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE enthalpy; entropy; gas basicity; Gibbs energy; ion-molecule reactions; proton affinity; protonation entropy; proton transfer ID PHOTOIONIZATION MASS-SPECTROMETRY; INFRARED-LASER SPECTROSCOPY; VARIABLE-TEMPERATURE; SUBSTITUTED BENZENES; FUNDAMENTAL-BAND; CARBON-DIOXIDE; HEAT; THERMOCHEMISTRY; HCO+; ENERGIES AB The available data on gas-phase basicities and proton affinities of approximately 1700 molecular, radical and atomic neutral species are evaluated and compiled. Tables of the data are sorted (1) according to empirical formula and (2) according to evaluated gas basicity. This publication constitutes an update of a similar evaluation published in 1984. (C) 1998 American Institute of Physics and American Chemical Society. C1 NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Hunter, EPL (reprint author), NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Young, Nigel/B-5472-2010 NR 73 TC 1602 Z9 1608 U1 19 U2 186 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD MAY-JUN PY 1998 VL 27 IS 3 BP 413 EP 656 PG 244 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA ZW486 UT WOS:000074415800001 ER PT J AU Griffies, SM Gnanadesikan, A Pacanowski, RC Larichev, VD Dukowicz, JK Smith, RD AF Griffies, SM Gnanadesikan, A Pacanowski, RC Larichev, VD Dukowicz, JK Smith, RD TI Isoneutral diffusion in a z-coordinate ocean model SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID GENERAL-CIRCULATION MODELS; TRACER TRANSPORTS; NORTH-ATLANTIC; THERMOCLINE AB This paper considers the requirements that must be satisfied in order to provide a stable and physically based isoneutral tracer diffusion scheme in a z-coordinate ocean model. Two properties are emphasized: 1) downgradient orientation of the diffusive fluxes along the neutral directions and 2) zero isoneutral diffusive flux of locally referenced potential density. It is shown that the Cox diffusion scheme does not respect either of these properties, which provides an explanation for the necessity to add a nontrivial background horizontal diffusion to that scheme. A new isoneutral diffusion scheme is proposed that aims to satisfy the stated properties and is found to require no horizontal background diffusion. C1 Princeton Univ, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08542 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. RP Griffies, SM (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, Route 1,Forrestal Campus, Princeton, NJ 08542 USA. RI Gnanadesikan, Anand/A-2397-2008 OI Gnanadesikan, Anand/0000-0001-5784-1116 NR 49 TC 154 Z9 154 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD MAY PY 1998 VL 28 IS 5 BP 805 EP 830 DI 10.1175/1520-0485(1998)028<0805:IDIAZC>2.0.CO;2 PG 26 WC Oceanography SC Oceanography GA ZP532 UT WOS:000073762900005 ER PT J AU Griffies, SM AF Griffies, SM TI The Gent-McWilliams skew flux SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID OCEAN CIRCULATION MODELS; TRACER TRANSPORTS; PARAMETERIZATION; ADVECTION AB This paper formulates tracer stirring arising from the Gent-McWiliiams (GM) eddy-induced transport in terms of a skew-diffusive flux. A skew-diffusive tracer flux is directed normal to the tracer gradient, which is in contrast to a diffusive tracer flux directed down the tracer gradient. Analysis of the GM skew flux provides an understanding of the physical mechanisms prescribed by GM stirring, which is complementary to the more familiar advective flux perspective. Additionally, it unifies the tracer mixing operators arising from Redi isoneutral diffusion and GM stirring. This perspective allows for a computationally efficient and simple manner in which to implement the GM closure in z-coordinate models. With this approach, no more computation is necessary than when using isoneutral diffusion alone. Additionally. the numerical realization of the skew flux is significantly smoother than the advective flux. The reason is that to compute the skew flux, no gradient of the diffusivity or isoneutral slope is taken, whereas such a gradient is needed for computing the advective flux. The skew-flux formulation also exposes a striking cancellation of terms that results when the GM diffusion coefficient is identical to the Redi isoneutral diffusion coefficient. For this case, the horizontal components to the tracer flux are aligned down the horizontal tracer gradient, and the resulting computational cost of Redi diffusion plus GM skew diffusion is roughly half that needed for Redi diffusion alone. C1 Princeton Univ, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Griffies, SM (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, Route 1,Forrestal Campus, Princeton, NJ 08542 USA. EM smg@gfdl.gov NR 36 TC 221 Z9 221 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD MAY PY 1998 VL 28 IS 5 BP 831 EP 841 DI 10.1175/1520-0485(1998)028<0831:TGMSF>2.0.CO;2 PG 11 WC Oceanography SC Oceanography GA ZP532 UT WOS:000073762900006 ER PT J AU Wineland, DJ Monroe, C Itano, WM Leibfried, D King, BE Meekhof, DM AF Wineland, DJ Monroe, C Itano, WM Leibfried, D King, BE Meekhof, DM TI Experimental issues in coherent quantum-state manipulation of trapped atomic ions SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Review DE coherent control; entangled states; laser cooling and trapping; quantum computation; quantum state engineering; trapped ions ID BOSE-EINSTEIN CONDENSATION; LASER-COOLED IONS; ERROR-CORRECTING CODES; SCHRODINGER-CAT STATES; ZERO-POINT ENERGY; OF-MASS MOTION; PAUL TRAP; NONCLASSICAL STATES; FREQUENCY STANDARD; SPONTANEOUS EMISSION AB Methods for, and limitations to, the generation of entangled states of trapped atomic ions are examined. As much as possible, state manipulations are described in terms of quantum logic operations since the conditional dynamics implicit in quantum logic is central to the creation of entanglement. Keeping with current interest, some experimental issues in the proposal for trapped-ion quantum computation by J. I. Cirac and P.Zoller (University of Innsbruck) are discussed. Several possible decoherence mechanisms are examined and what may be the more important of these are identified. Some potential applications for entangled states of trapped-ions which lie outside the immediate realm of quantum computation are also discussed. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. RI Monroe, Christopher/G-8105-2011 NR 345 TC 765 Z9 773 U1 8 U2 89 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 1998 VL 103 IS 3 BP 259 EP 328 DI 10.6028/jres.103.019 PG 70 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 111BH UT WOS:000075417100001 PM 28009379 ER PT J AU Cross, JO Elam, WT Harris, VG Kirkland, JP Bouldin, CE Sorensen, LB AF Cross, JO Elam, WT Harris, VG Kirkland, JP Bouldin, CE Sorensen, LB TI Sample-angle feedback for diffraction anomalous fine-structure spectroscopy SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE diffraction anomalous fine structure; XAFS; anomalous scattering; sample-angle feedback ID MONOCHROMATOR AB Diffraction anomalous fine-structure (DAFS) experiments measure Bragg peak intensities as continuous functions of photon energy near a core-level excitation. Measuring the integrated intensity at each energy makes the experiments prohibitively slow; however, in many cases DAFS can be collected quickly by measuring only the peak intensity at the center of the rocking curve. A piezoelectric-actuator-driven stage has been designed and tested as part of a sample-angle feedback circuit for locking onto the maximum of the rocking curve while the energy is scanned. Although software peak-tracking requires only a simple calculation of diffractometer angles, it is found that the additional hardware feedback dramatically improves the reproducibility of the data. C1 USN, Res Lab, Washington, DC 20375 USA. SFA Inc, Landover, MD 20785 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Washington, Seattle, WA 98195 USA. RP Cross, JO (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Harris, Vincent/A-8337-2009 NR 7 TC 3 Z9 3 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 911 EP 913 DI 10.1107/S0909049597014313 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200230 PM 15263694 ER PT J AU Read, DT AF Read, DT TI Piezo-actuated microtensile test apparatus SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE closed loop; displacement; force; piezoelectric; servo; strain; stress; thin film ID THIN-FILMS; MECHANICAL-PROPERTIES AB The design and performance of a microtensile test device designed for measuring the mechanical properties of thin films are reported. The moving grip is cantilevered to avoid friction. Piezoelectric actuation allows precise control of the applied tension. Force is measured indirectly using an eddy-current sensor near a flexible measuring beam, and grip displacement is measured using two similar displacement sensors. The apparatus is constructed for use with specially designed specimen assemblies in which the thin film to be tested is suspended across a silicon frame. The apparatus is rigid enough that the frames can be cut without applying tension to the thin-film tensile specimen. The tester is run in closed-loop control through a laboratory computer, which records force, displacement, and other parameters 5 times per second. Key capabilities are: stroke, 50 mu m; maximum force, 1 N; minimum cycle time, 2 s; displacement resolution, +/-20 nm; and force resolution, +/-200 mu N. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Read, DT (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. NR 11 TC 27 Z9 30 U1 0 U2 2 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD MAY PY 1998 VL 26 IS 3 BP 255 EP 259 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA ZP263 UT WOS:000073734800010 ER PT J AU Smith, EA Lamm, JE Adler, R Alishouse, J Aonashi, K Barrett, E Bauer, P Berg, W Chang, A Ferraro, R Ferriday, J Goodman, S Grody, N Kidd, C Kniveton, D Kummerow, C Liu, G Marzano, F Mugnai, A Olson, W Petty, G Shibata, A Spencer, R Wentz, F Wilheit, T Zipser, E AF Smith, EA Lamm, JE Adler, R Alishouse, J Aonashi, K Barrett, E Bauer, P Berg, W Chang, A Ferraro, R Ferriday, J Goodman, S Grody, N Kidd, C Kniveton, D Kummerow, C Liu, G Marzano, F Mugnai, A Olson, W Petty, G Shibata, A Spencer, R Wentz, F Wilheit, T Zipser, E TI Results of WetNet PIP-2 project SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Review ID SENSOR MICROWAVE IMAGER; PROBABILITY-DISTRIBUTION FUNCTIONS; PHYSICAL PRECIPITATION RETRIEVAL; VERTICAL STRUCTURE INFORMATION; CLOUD-RADIATION MODEL; OCEAN RAIN RATE; SATELLITE MEASUREMENTS; LIQUID WATER; SNOW COVER; RADIOMETRIC MEASUREMENTS AB The second WetNet Precipitation Intercomparison Project (PIP-2) evaluates the performance of 20 satellite precipitation retrieval algorithms, implemented for application with Special Sensor Microwave/Imager (SSM/I) passive microwave (PMW) measurements and run for a set of rainfall case studies at full resolution-instantaneous space-timescales, The cases are drawn from over the globe during all seasons, for a period of 7 yr, over a 60 degrees N-17 degrees S latitude range. Ground-based data were used for the intercomparisons, principally based on radar measurements but also including rain gauge measurements. The goals of PIP-2 are I) to improve performance and accuracy of different SSM/I algorithms at full resolution-instantaneous scales by seeking a better understanding of the relationship between microphysical signatures in the PMW measurements and physical laws employed in the algorithms; 2) to evaluate the pros and cons of individual algorithms and their subsystems in order to seek optimal "front-end" combined algorithms; and 3) to demonstrate that PMW algorithms generate acceptable instantaneous rain estimates. It is found that the bias uncertainty of many current PMW algorithms is on the order of +/-30%. This level is below that of the radar and rain gauge data specially collected for the study, so that it is nor possible to objectively select a best algorithm based on the ground data validation approach. By decomposing the intercomparisons into effects due to rain detection (screening) and effects due to brightness temperature-rain rate conversion, differences among the algorithms are partitioned by rain area and rain intensity: For ocean, the screening differences mainly affect the light rain rates, which do not contribute significantly to area-averaged rain rates. The major sources of differences in mean rain rates between individual algorithms stem from differences in how intense rain rates are calculated and the maximum rain rate allowed by a given algorithm. The general method of solution is not necessarily the determining factor in creating systematic rain-rate differences among groups of algorithms, as we find that the severity of the screen is the dominant factor in producing systematic group differences among land algorithms, while the input channel selection is the dominant factor in producing systematic group differences among ocean algorithms. The significance of these issues are examined through what is called "fan map" analysis. The paper concludes with a discussion on the role of intercomparison projects in seeking improvements to algorithms, and a suggestion on why moving beyond the "ground truth" validation approach by use of a calibration-quality forward model would be a step forward in seeking objective evaluation of individual algorithm performance and optimal algorithm design. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, NESDIS, Camp Springs, MD USA. Meteorol Res Inst, Tsukuba, Ibaraki 305, Japan. Univ Bristol, Dept Geog, Bristol BS8 1TH, Avon, England. Atmospher & Environm Res Inc, Cambridge, MA 02139 USA. NASA, George C Marshall Space Flight Ctr, Global Hydrol & Climate Ctr, Huntsville, AL 35812 USA. Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA. Univ Rome, Dept Elect Engn, Rome, Italy. CNR, Ist Fis Atmosfera, I-00044 Frascati, Italy. Caleum Res Corp, Silver Spring, MD USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. Remote Sensing Syst, Santa Rosa, CA USA. Texas A&M Univ, Dept Meteorol, College Stn, TX 77843 USA. RP Smith, EA (reprint author), Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. EM esmith@metsat.met.fsu.edu RI Zhang, YIng/F-5751-2011; Liu, Guosheng/D-3479-2011; Petty, Grant/E-3118-2012; Wilheit, Thomas/G-9438-2012; Kidd, Christopher/H-9910-2014; Ferraro, Ralph/F-5587-2010; PMM, JAXA/K-8537-2016 OI Liu, Guosheng/0000-0001-7899-6125; Ferraro, Ralph/0000-0002-8393-7135; NR 124 TC 131 Z9 134 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAY 1 PY 1998 VL 55 IS 9 BP 1483 EP 1536 DI 10.1175/1520-0469(1998)055<1483:ROWPP>2.0.CO;2 PG 54 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZM952 UT WOS:000073592900002 ER PT J AU Berg, W Olson, W Ferraro, R Goodman, SJ LaFontaine, FJ AF Berg, W Olson, W Ferraro, R Goodman, SJ LaFontaine, FJ TI An assessment of the first- and second-generation navy operational precipitation retrieval algorithms SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SSM/I; GHZ AB Rainfall estimates produced from the Special Sensor Microwave/Imager (SSM/I) data have been utilized operationally by the United States Navy since the launch of the first SSM/I sensor in June of 1987. The navy initially contracted Hughes Aircraft Company to develop a rainfall-retrieval algorithm prior to the launch of SSM/I. This first-generation operational navy rainfall retrieval algorithm, referred to as the D-Matrix algorithm, was used until the development of the second-generation algorithm by the SSM/I Calibration/Validation team, which has subsequently been replaced by a third-generation algorithm developed by the National Oceanic and Atmospheric Administration/National Environmental Satellite, Data and Information System. Results from both the D-Matrix and Cal/Val algorithms have been included in a total of five algorithm intercomparison projects conducted through the Global Precipitation Climatology Project and WetNet. A comprehensive summary of both quantitative and qualitative results from these intercomparisons is given detailing many of the strengths and weaknesses of the algorithms. Based on these results, the D-Matrix algorithm was found to produce excessively large estimates over land and to poorly represent the spatial structure of rainfall systems, especially at higher latitudes. The Cal/Val algorithm produces more realistic structure within storm systems but appears to overestimate the region of precipitation for many systems and significantly underestimates regions of intense rainfall. While the Cal/Val algorithm appears to provide better instantaneous rainfall estimates in the Tropics, the D-Matrix algorithm provides reasonable time-averaged results for monthly or longer periods. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Caelum Res Corp, Silver Spring, MD USA. NOAA, Satellite Res Lab, Camp Springs, MD USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Hughes STX, Huntsville, AL USA. RP Berg, W (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Campus Box 449, Boulder, CO 80309 USA. RI Ferraro, Ralph/F-5587-2010 OI Ferraro, Ralph/0000-0002-8393-7135 NR 23 TC 14 Z9 16 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAY 1 PY 1998 VL 55 IS 9 BP 1558 EP 1575 DI 10.1175/1520-0469(1998)055<1558:AAOTFA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZM952 UT WOS:000073592900004 ER PT J AU Ferraro, RR Smith, EA Berg, W Huffman, GJ AF Ferraro, RR Smith, EA Berg, W Huffman, GJ TI A screening methodology for passive microwave precipitation retrieval algorithms SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GLOBAL OCEANIC PRECIPITATION; RAIN-RATE; PHYSICAL RETRIEVALS; SSM/I MEASUREMENTS; SNOW COVER; IMAGER; CLASSIFICATION; IDENTIFICATION; PARAMETERS AB The success of any passive microwave precipitation retrieval algorithm relies on the proper identification of rain areas and the elimination of surface areas that produce a signature similar to that of precipitation. A discussion on the impact of and on methods that identify areas of rain, snow cover, deserts, and semiarid conditions over land, and rain, sea ice, strong surface winds, and clear, calm conditions over ocean, are presented. Additional artifacts caused by coastlines and Special Sensor Microwave/Imager data errors are also discussed, and methods to alleviate their impact are presented. The strengths and weaknesses of the "screening" techniques are examined through application on various case studies used in the WetNet PIP-2. Finally, a methodology to develop a set of screens for use as a common rainfall indicator for the intercomparison of the wide variety of algorithms submitted to PIP-2 is described. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. Florida State Univ, Tallahassee, FL 32306 USA. NOAA, CIRES, Boulder, CO USA. NASA, Goddard Space Flight Ctr, SSAI, Greenbelt, MD 20771 USA. RP Ferraro, RR (reprint author), NOAA, NESDIS, Off Res & Applicat, 5200 Auth Rd,Room 601Q, Camp Springs, MD 20746 USA. RI Huffman, George/F-4494-2014; Ferraro, Ralph/F-5587-2010 OI Huffman, George/0000-0003-3858-8308; Ferraro, Ralph/0000-0002-8393-7135 NR 41 TC 116 Z9 119 U1 0 U2 10 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 1 PY 1998 VL 55 IS 9 BP 1583 EP 1600 DI 10.1175/1520-0469(1998)055<1583:ASMFPM>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZM952 UT WOS:000073592900006 ER PT J AU Clifford, EP Wenthold, PG Lineberger, WC Ellison, GB Wang, CX Grabowski, JJ Vila, F Jordan, KD AF Clifford, EP Wenthold, PG Lineberger, WC Ellison, GB Wang, CX Grabowski, JJ Vila, F Jordan, KD TI Properties of tetramethyleneethane (TME) as revealed by ion chemistry and ion photoelectron spectroscopy SO JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2 LA English DT Article ID LOW-LYING TRIPLET; GROUND-STATE TRIPLET; GAS-PHASE ION; SINGLET-STATES; ELECTRON-AFFINITY; ATOMIC OXYGEN; CHEMICAL-REACTIONS; RADICAL-ANION; NEGATIVE-IONS; ORTHO-BENZYNE AB The negative ion chemistry and photoelectron spectra of [CH2=C(CH3)-C(CH2)(2)](-) and [(CH2)(2)C-C(CH2)(2)](-) have been studied. The negative ion photoelectron spectra reveal the tetramethyleneethane diradical, TME, to have two low-lying electronic states, (X) over tilde and (a) over tilde. The ground (X) over tilde state is assigned as [TME] (1)A and the excited (a) over tilde state as [TME] B-3(1). The energy separation between these states is about 2 kcal mol(-1); Delta E[(a) over tilde B-3(1) <-- (X) over tilde(1)A] congruent to 0.1 eV. The experimental electron affinities of the neutrals are: E-ea[CH2=C(CH3)-C(CH2)(2)] = 0.654 +/- 0.010 eV and E-ea[(CH2)(2)C-C(CH2)(2)] = 0.855 +/- 0.010 eV. The experimental gas phase acidities are: Delta(acid)H(298)[CH2=C(CH3)-C(CH2)CH2-H] = 388 +/- 3 kcal mol(-1) and Delta(f)H(298)[(CH2)(2)C-C(CH2)-CH2-H] = 388 +/- 4 kcal mol(-1). These findings can be used to establish the bond energies and heats of formation: DH298[CH2=C(CH3)-C(CH2)CH2-H] = 90 +/- 3 kcal mol(-1) and Delta(f)H(298)[(CH2)(2)C-C(CH2)=CH2] = 48 +/- 3 kcal mol(-1); DH298[(CH2)(2)C-C(CH2)CH2-H] = 94 +/- 4 kcal mol(-1) and Delta(f)H(298)[(CH2)(2)C-C(CH2)(2)] = 90 +/- 5 kcal mol(-1). C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Pittsburgh, Dept Chem, Pittsburgh, PA 15260 USA. RP Clifford, EP (reprint author), Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. NR 50 TC 42 Z9 42 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 0300-9580 J9 J CHEM SOC PERK T 2 JI J. Chem. Soc.-Perkin Trans. 2 PD MAY PY 1998 IS 5 BP 1015 EP 1022 DI 10.1039/a707322d PG 8 WC Chemistry, Organic; Chemistry, Physical SC Chemistry GA ZN810 UT WOS:000073684900002 ER PT J AU Coyle, ST Scheinfein, MR Blue, JL AF Coyle, ST Scheinfein, MR Blue, JL TI Co on stepped Cu(100) surfaces: A comparison of experimental data with Monte Carlo growth simulations SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID COBALT FILMS; THIN-FILMS AB Monte Carlo simulations of the growth of Co/Cu(100) in the presence of steps, terraces, and kinks were performed. The beginning stages of Co growth enhance the roughening of step edges. Interdiffusion increases with increasing temperature and decreasing growth rate. Varying the step orientation from [100] to [110] produced a steady decrease in interdiffusion. The lateral width of the interdiffused region in steps (10%-90% concentration) is similar to 0.7-1.5 nm. Decreasing the Co-Cu binding energy produced an increase in the frequency of double-height islands and step edge decoration. A value of similar to 0.21 eV/nearest neighbor bond produced step edge decoration indicative of a Schwoebel barrier with very few double-height islands. Simulation results were compared to growth results obtained via nanometer resolution ultrahigh vacuum scanning electron microscopy. Island statistics compare favorably with growth results. Experimentally observed large etching features at steps were not well reproduced by the model, suggesting an exchange mechanism may be important. (C) 1998 American Vacuum Society. [S0734-2101(98)00703-9]. C1 Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Coyle, ST (reprint author), Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1342 EP 1347 DI 10.1116/1.581148 PN 1 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400084 ER PT J AU Tulchinsky, DA Kelley, MH McClelland, JJ Gupta, R Celotta, RJ AF Tulchinsky, DA Kelley, MH McClelland, JJ Gupta, R Celotta, RJ TI Fabrication and domain imaging of iron magnetic nanowire arrays SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID FOCUSED ATOMIC DEPOSITION; NANOSTRUCTURE FABRICATION; LASER AB Arrays of magnetic nanowires are fabricated by using a corrugated surface, produced by chromium atoms laser-focused in a one-dimensional standing wave, as a shadow mask for an iron evaporator. The deposited iron forms a periodic array consisting of thousands of 20-40 nm high ferromagnetic fines with width of similar to 100 nm, spaced every 213 nm, and having aspect ratios (width:length) of 1:1500. Images of the magnetic domain structures of these nanowires are obtained by scanning electron microscopy with polarization analysis. Elongated domains similar to 100 nm wide and similar to 16 mu m long are observed. C1 NIST, Gaithersburg, MD 20899 USA. RP Tulchinsky, DA (reprint author), NIST, Gaithersburg, MD 20899 USA. RI McClelland, Jabez/A-2358-2015 OI McClelland, Jabez/0000-0001-5672-5965 NR 19 TC 12 Z9 12 U1 1 U2 27 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1817 EP 1819 DI 10.1116/1.581113 PN 2 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT992 UT WOS:000074150500078 ER PT J AU Bertness, KA Hickernell, RK Hays, SP Christensen, DH AF Bertness, KA Hickernell, RK Hays, SP Christensen, DH TI Noise reduction in optical in situ measurements for molecular beam epitaxy by substrate wobble normalization SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 16th North American Conference on Molecular Beam Epitaxy CY OCT 05-08, 1997 CL UNIV MICHIGAN, ANN ARBOR, MICHIGAN HO UNIV MICHIGAN ID DISTRIBUTED BRAGG REFLECTORS; SPECTROSCOPIC ELLIPSOMETRY; PYROMETRIC INTERFEROMETRY; GROWTH; GAAS; TEMPERATURE AB We demonstrate a normalization method for removing noise introduced into optical in sial measurements by sample rotation wobble;during molecular beam epitaxy. The technique consists of measuring the angle of rotation of the sample through optical triggers attached to the sample manipulator rotation drive, acquiring a normalization curve at the various trigger points, then applying the normalization appropriate to each trigger to subsequent data. This cyclic normalization is demonstrated on normal-incidence optical reflection data and atomic absorption measurements in which the flux-monitor light beam is reflected from the sample to allow determination of layer thickness in addition to atomic flux. Noise reductions by factors of 3 to 30 were observed in both systems, with the larger improvements for samples with larger wobble angles, while preserving the original time resolution of the data. We achieve normalized optical reflectance data with a noise standard deviation of 1% over a period of one to two hours and similar results for atomic absorption data on shorter time scales. The technique is limited by the long-term mechanical stability of the manipulator and collection optics. C1 Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Bertness, KA (reprint author), Univ Colorado, Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80309 USA. NR 13 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1998 VL 16 IS 3 BP 1492 EP 1497 DI 10.1116/1.589973 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA ZV375 UT WOS:000074298300114 ER PT J AU Berkeland, DJ Miller, JD Cruz, FC Young, BC Bergquist, JC Itano, WM Wineland, DJ AF Berkeland, DJ Miller, JD Cruz, FC Young, BC Bergquist, JC Itano, WM Wineland, DJ TI High-accuracy microwave and optical frequency standards using laser-cooled Hg+ ions SO LASER PHYSICS LA English DT Article; Proceedings Paper CT 2nd International Conference on Modern Problems of Laser Physics CY JUL 28-AUG 02, 1997 CL NOVOSIBIRSK, RUSSIA ID TRAP; SPECTROSCOPY AB We discuss frequency standards based on laser-cooled Hg-199(+) ions confined in cryogenic rf (Paul) traps. In one experiment, the frequency of a microwave source is servoed to the ions' ground-state hyperfine transition at 40.5 GHz. For seven ions and a Ramsey free precession time of 100 s, the fractional frequency stability is 3.3 (2) x 10(-13) tau(-1/2) for measurement times tau < 2 h. The ground-state hyperfine interval is measured to be 40507347996.84159(20)(41) Hz, where the first number in parentheses is the uncertainty due to statistics and systematic effects, and the second is the uncertainty in the frequency of the time scale to which the standard is compared. In a second experiment under development, a strong-binding cryogenic trap will confine a single ion used for an optical frequency standard based on a narrow electric quadrupole transition at 282 nm. The bandwidth of the laser used to drive this transition is less than 10 Hz at 563 nm. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Berkeland, DJ (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, 325 Broadway, Boulder, CO 80303 USA. EM berkeland@boulder.nist.gov RI Cruz, Flavio/A-6346-2012 OI Cruz, Flavio/0000-0003-3995-7910 NR 27 TC 1 Z9 1 U1 2 U2 3 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 USA SN 1054-660X J9 LASER PHYS JI Laser Phys. PD MAY-JUN PY 1998 VL 8 IS 3 BP 673 EP 678 PG 6 WC Optics; Physics, Applied SC Optics; Physics GA ZV831 UT WOS:000074345700021 ER PT J AU Sun, JX Pei, PT Hu, ZS Hsu, SM AF Sun, JX Pei, PT Hu, ZS Hsu, SM TI A modified thin-film oxygen uptake test (TFOUT) for lubricant oxidative stability study SO LUBRICATION ENGINEERING LA English DT Article; Proceedings Paper CT 50th Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 14-19, 1995 CL CHICAGO, ILLINOIS SP Soc Tribologists & Lubricat Engineers DE bench test; oxidation; lubricant degradation/stability; lubricant AB The thin-film oxygen uptake test (TFOUT) is a laboratory bench test developed to measure the oxidation stability of lubricants. It was originally developed to monitor the batch to batch variation of re-refined lubricating basestocks under the Recycled Oil Program which was mandated by the U.S. Congress under RCRA. A catalyst package was developed for the TFOUT test to simulate the key chemical reactions encountered in the IIID engine test As the engine test continues to evolve, the Sequence IIIE test was introduced and the chemistry changed. A new catalyst package for IIIE was developed and made available in 1991. The package contains oxidized-nitrated fuel fraction, a pure nitro-compound, water and a mixture of metal catalysts. User feedback suggested a potential antagonistic effect between the pure nitrocompounds and same amine antioxidants contained in some lubricant formulations. At the same time, the engine test reference oils used in the original IIIE correlation study were changed to reflect some recent technology Bench test correlation study based on these new oils suggested some loss of correlation. This paper describes the successful development of a new catalyst package that circumvents these problems. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sun, JX (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 29 TC 3 Z9 3 U1 1 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 LUBR ENG JI Lubric. Eng. PD MAY PY 1998 VL 54 IS 5 BP 12 EP 19 PG 8 WC Engineering, Mechanical SC Engineering GA ZN030 UT WOS:000073601000002 ER PT J AU Iverson, WP AF Iverson, WP TI Possible source of a phosphorus compound produced by sulfate-reducing bacteria that cause anaerobic corrosion of iron SO MATERIALS PERFORMANCE LA English DT Article AB The corrosion of Fe under anaerobic environments has been associated with sulfate-reducing bacteria (SRB). Previously it was believed that these organisms stimulated ed corrosion through the removal of H from the surface of Fe. An alternative mechanism, which could explain the high corrosion rates in nature, has been proposed. It has been found that SXB produce a volatile P-containing compound that is highly corrosive to Fe. This P compound is produced from inositol hexaphosphoric acid (C6H18O24P6), a common material in plants, and not from inorganic phosphate. C1 Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RP Iverson, WP (reprint author), Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. NR 15 TC 8 Z9 9 U1 0 U2 6 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0094-1492 J9 MATER PERFORMANCE JI Mater. Perform. PD MAY PY 1998 VL 37 IS 5 BP 46 EP 49 PG 4 WC Materials Science, Characterization & Testing SC Materials Science GA ZM523 UT WOS:000073548700015 ER PT J AU Bentz, DP Garboczi, EJ Quenard, DA AF Bentz, DP Garboczi, EJ Quenard, DA TI Modelling drying shrinkage in reconstructed porous materials: application to porous Vycor glass SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID SMALL-ANGLE SCATTERING; ELECTRICAL-CONDUCTIVITY; PHASE-EQUILIBRIA; MEDIA; PERMEABILITY; ADSORPTION; INCLUSIONS; MORTAR; FLUIDS; ENERGY AB A three-dimensional representation of the microstructure of porous Vycor glass was generated from a transmission electron micrograph, and was analysed to compute the locations of all capillary-condensed water as a function of relative humidity. On solid surfaces where capillary-condensed water was not present, an adsorbed water layer, whose thickness is a function of relative humidity, was placed. As a function of relative humidity, fixed pressures were specified in all capillary-condensed water, and the change in specific surface free energy with relative humidity was taken into account for the adsorbed water layers. New finite-element codes were developed to determine the drying shrinkage, in response to the changes in the specific surface free energy of the adsorbed water layers and to the fixed pressures in the capillary condensed water. Existing finite-element and finite-difference codes were used to evaluate the elastic moduli, the electrical and thermal conductivity, and the fluid permeability of the material. Bulk properties such as fluid permeability and electrical and thermal conductivity agreed well with experiment. By adjusting the elastic moduli of the solid backbone, which are not experimentally determined quantities, the computed porous glass elastic moduli, and computed low and high relative humidity shrinkage all agreed well (less than or equal to 10%) with experimental values. At intermediate relative humidities, the agreement for shrinkage was worse, partly due to inaccuracies in the simulated water desorption curve, and partly due to the fact that water-induced swelling of the solid backbone, an effect that is probably present in the real material, was not taken into account in the model computations. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Ctr Sci & Tech Batiment, F-38400 St Martin Dheres, France. RP Bentz, DP (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 76 TC 89 Z9 92 U1 0 U2 9 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD MAY PY 1998 VL 6 IS 3 BP 211 EP 236 DI 10.1088/0965-0393/6/3/002 PG 26 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 108AX UT WOS:000075244800002 ER PT J AU Pasch, RJ Avila, LA Jiing, JG AF Pasch, RJ Avila, LA Jiing, JG TI Atlantic tropical systems of 1994 and 1995: A comparison of a quiet season to a near-record-breaking one SO MONTHLY WEATHER REVIEW LA English DT Article ID WAVE DISTURBANCES; HURRICANE SEASON; EASTERLY WAVES; AFRICA AB Totals of 70 and 63 tropical waves (also known as African or easterly waves) were counted in the Atlantic basin during the 1994 and 1995 hurricane seasons. These waves led to the formation of 9 of the 12 total number of tropical cyclones in 1994 and 19 of the 21 total number of tropical cyclones in 1995. Tropical waves contributed to the formation of 75% of the eastern Pacific tropical cyclones in 1994 and 73% in 1995. Upper- and lower-level prevailing wind patterns observed during the below-normal season of 1994 and the very active one of 1995 are discussed. Tropical wave characteristics between the two years are compared. C1 NOAA, NWS, Natl Hurricane Ctr, Trop Predict Ctr, Miami, FL 33165 USA. RP Pasch, RJ (reprint author), NOAA, NWS, Natl Hurricane Ctr, Trop Predict Ctr, 11691 SW 17th St, Miami, FL 33165 USA. NR 30 TC 27 Z9 27 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1998 VL 126 IS 5 BP 1106 EP 1123 DI 10.1175/1520-0493(1998)126<1106:ATSOAA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZL980 UT WOS:000073492800002 ER PT J AU Lawrence, MB Mayfield, BM Avila, LA Pasch, RJ Rappaport, EN AF Lawrence, MB Mayfield, BM Avila, LA Pasch, RJ Rappaport, EN TI Atlantic hurricane season of 1995 SO MONTHLY WEATHER REVIEW LA English DT Article AB The 1995 Atlantic hurricane season is described. There were eight tropical storms and 11 hurricanes for a total of 19 named tropical cyclones in the Atlantic basin during 1995. This is the second-largest number of tropical storms and hurricanes in over 100 years of records. Thirteen named tropical cyclones affected land. C1 NOAA, NWS, NHC, Trop Predict Ctr, Miami, FL 33165 USA. RP Lawrence, MB (reprint author), NOAA, NWS, NHC, Trop Predict Ctr, 11691 SW 17th St, Miami, FL 33165 USA. NR 8 TC 32 Z9 32 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1998 VL 126 IS 5 BP 1124 EP 1151 DI 10.1175/1520-0493(1998)126<1124:AHSO>2.0.CO;2 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZL980 UT WOS:000073492800003 ER PT J AU Rappaport, EN Avila, LA Lawrence, MB Mayfield, M Pasch, RJ AF Rappaport, EN Avila, LA Lawrence, MB Mayfield, M Pasch, RJ TI Eastern North Pacific hurricane season of 1995 SO MONTHLY WEATHER REVIEW LA English DT Article AB The 1995 eastern North Pacific hurricane season is reviewed. The activity comprised 11 tropical cyclones, consisting of seven hurricanes, three tropical storms, and one tropical depression. Hurricane Ismael caused a large loss of life in thr southern Gulf of California. C1 NOAA, NWS, NHC, Trop Predict Ctr, Miami, FL 33165 USA. RP Rappaport, EN (reprint author), NOAA, NWS, NHC, Trop Predict Ctr, 11691 SW 17th St, Miami, FL 33165 USA. NR 3 TC 3 Z9 3 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1998 VL 126 IS 5 BP 1152 EP 1162 DI 10.1175/1520-0493(1998)126<1152:ENPHSO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZL980 UT WOS:000073492800004 ER PT J AU Landsea, CW Bell, GD Gray, WM Goldenberg, SB AF Landsea, CW Bell, GD Gray, WM Goldenberg, SB TI The extremely active 1995 Atlantic hurricane season: Environmental conditions and verification of seasonal forecasts SO MONTHLY WEATHER REVIEW LA English DT Article ID SAHELIAN MONSOON RAINFALL; UPPER-TROPOSPHERIC TROUGH; WEST-AFRICAN RAINFALL; EL-NINO; STRONG ASSOCIATION; TROPICAL CYCLONES; INTENSE; VARIABILITY; OSCILLATION; CIRCULATION AB The 1995 Atlantic hurricane season was a year of near-record hurricane activity with a total of 19 named storms (average is 9.3 for the base period 1950-90) and 11 hurricanes (average is 5.8), which persisted for a total of 121 named storm days (average is 46.6) and 60 hurricane days (average is 23.9), respectively. Then were five intense (or major) Saffir-Simpson category 3, 4, or 5 hurricanes (average is 2.3 intense hurricanes) with 11.75 intense hurricane days (average is 4.7). The net tropical cyclone activity, based upon the combined values of named storms, hurricanes. intense hurricanes, and their days present, was 229% of the average, Additionally. 1995 saw the return of hurricane activity to the deep tropical latitudes: seven hurricanes developed south of 25 degrees N (excluding all of the Gulf of Mexico) compared with just one during all of 1991-94. Interestingly, all seven storms that formed south of 20 degrees N in August and September recurved to the northeast without making landfall in the United States. The sharply increased hurricane activity during 1995 is attributed to the juxtaposition of virtually all of the large-scale features over the tropical North Atlantic that favor tropical cyclogenesis and development, These include extremely low vertical wind shear, below-normal sea level pressure, abnormally warm ocean waters, higher than average amounts of total precipitable water, and a strong west phase of the stratospheric quasi-biennial oscillation. These various environmental factors were in strong contrast to those of the very unfavorable conditions that accompanied the extremely quiet 1994 hurricane season. The favorable conditions for the 1995 hurricane season began to develop as far back as late in the previous winter. Their onset well ahead of the start of the hurricane season indicates that they are a cause of the increased hurricane activity. and not an effect. The extreme duration of the atmospheric circulation anomalies over the tropical North Atlantic is partly attributed to a transition in the equatorial Pacific from warm episode conditions (El Nino) to cold episode conditions (La Nina) prior to the onset of the hurricane season. Though the season as a whole was extremely active, 1995`s Atlantic tropical cyclogenesis showed a strong intraseasonal variability with above-normal storm frequency during August and October and below normal for September This variability is likely attributed to changes in the upper-tropospheric circulation across the tropical North Atlantic, which resulted in a return to near-normal vertical shear during September Another contributing factor to the reduction in tropical cyclogenesis during September may have been a temporary return to near-normal SSTs across the tropical and subtropical North Atlantic, caused by the enhanced tropical cyclone activity during August. Seasonal hurricane forecasts for 1995 issued at Colorado State University on 30 November 1994, 5 June 1995, and 4 August 1995 correctly anticipated an above-average season, but underforecast the extent of the extreme hurricane activity. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, NOAA Climate & Global Change Fellowship, Miami, FL 33149 USA. NOAA, Natl Weather Serv, NCEP, Climate Predict Ctr, Washington, DC 20233 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Landsea, CW (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, NOAA Climate & Global Change Fellowship, 4301 Rickenbacher Causeway, Miami, FL 33149 USA. EM landsea@aoml.noaa.gov RI Goldenberg, Stanley/C-5965-2014 OI Goldenberg, Stanley/0000-0001-6730-5819 NR 63 TC 91 Z9 95 U1 0 U2 10 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1998 VL 126 IS 5 BP 1174 EP 1193 DI 10.1175/1520-0493(1998)126<1174:TEAAHS>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZL980 UT WOS:000073492800006 ER PT J AU Leslie, LM LeMarshall, JF Morison, RP Spinoso, C Purser, RJ Pescod, N Seecamp, R AF Leslie, LM LeMarshall, JF Morison, RP Spinoso, C Purser, RJ Pescod, N Seecamp, R TI Improved hurricane track forecasting from the continuous assimilation of high quality satellite wind data SO MONTHLY WEATHER REVIEW LA English DT Article ID NUMERICAL WEATHER PREDICTION; CLOUD DRIFT WINDS; IMPACT; MODEL AB Despite recent improvements in the accuracy of hurricane track forecasts, mean position errors still remain unacceptably large. For example, recurvature is captured poorly by forecast models and can produce excessively large position errors. This study addresses the problem of hurricane track forecasting in three ways. First, the initial conditions for the forecast model are augmented by a dense coverage of high spatial and temporal resolution satellite-derived wind vectors. Second, to gauge the extent to which this additional four-dimensional detail of the atmospheric structure can he exploited, three distinct types of data assimilation methods are examined. These are 1) conventional (intermittent, cycled) 6-h assimilation, 2) nudging over a 12- or 24-h period up to the initial time, and 3) recently developed barotropic and four-dimensional variational assimilation schemes, also over a 12- or 24-h period. The nudging and variational methods are continuous assimilation procedures and incorporate satellite-derived winds, typically at 6-h frequencies, but up to hourly frequencies in trials over the Australian region. Over the Atlantic basin, only a 6-h frequency of high-density satellite-derived wind vectors was available for the 1995 season. Third, a very high-resolution (15 km) semi-implicit, semi-Lagrangian model provided forecasts out to 72 h. The present study describes the direct application to the Atlantic basin, for die specific case of Hurricane Opal, of data assimilation and prediction procedures developed for tropical cyclones over the Australian Pacific basin. A series of forecasts was made, from the two initial times 0000 and 1200 UTC 2 October 1995, respectively. In these cases, where CLIPER (climatology and persistence) and other conventional forecast guidance was poor, the nudging and variational assimilation procedures, which were those that best utilized the high spatial and temporal resolution satellite-derived winds, produced greatly improved forecasts. C1 Univ New S Wales, Sch Math, Sydney, NSW 2052, Australia. Bur Meteorol Res Ctr, Melbourne, Vic, Australia. Royal Melbourne Inst Technol, Melbourne, Vic 3001, Australia. Natl Ctr Environm Predict, Washington, DC USA. RP Leslie, LM (reprint author), Univ New S Wales, Sch Math, Sydney, NSW 2052, Australia. NR 17 TC 52 Z9 54 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1998 VL 126 IS 5 BP 1248 EP 1257 DI 10.1175/1520-0493(1998)126<1248:IHTFFT>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZL980 UT WOS:000073492800011 ER PT J AU Powell, MD Houston, SH AF Powell, MD Houston, SH TI Surface wind fields of 1995 Hurricanes Erin, Opal, Luis, Marilyn, and Roxanne at landfall SO MONTHLY WEATHER REVIEW LA English DT Article ID ANDREW LANDFALL; SOUTH FLORIDA AB Hurricanes Erin, Opal, Luis, Marilyn, and Roxanne were the most destructive hurricanes of 1995. At landfall, Luis and Marilyn contained maximum sustained winds (marine exposure) estimated at near 60 and 46 m s(-1), respectively. The strongest landfalling storm of the 1995 season, Luis, decreased in intensity from a category 4 to 3 on the Saffir-Simpson scale shortly before the eyewall crossed the Islands of Antigua, Barbuda, St. Kitts-Nevis, St. Barthelemy, St. Martin, and Anguilla. Hurricane Marilyn strengthened as it approached the U.S. Virgin Islands, with St. Thomas bearing the brunt of the north and south eyewall winds of 46 m s(-1) (marine exposure) and St. Croix being affected by the relatively weak western eyewall peak winds of 35-40 m s(-1) (marine exposure). For Luis and Marilyn only surface winds with marine exposures were analyzed because of unknown small-scale interactions associated with complex island terrain with 500-1000-m elevations. Wind engineering studies suggest that wind acceleration over blunt ridges can increase or "speed up" winds by 20%-80%. Topographic effects were evident in damage debris analyses and suggest that an operational method of assessing terrain-induced wind gusts (such as a scaled down mesoscale model) is needed. After landfall as a marginal hurricane over central Florida, Hurricane Erin regained strength over the Gulf of Mexico with a well-defined radar reflectivity structure. Erin struck the Florida panhandle near Navarre Beach with maximum sustained surface winds of 35-40 m s(-1) affecting the Destin-Ft. Walton area. Hurricane Opal made landfall in nearly the identical area as Erin, with maximum sustained surface winds of 40-45 m s(-1), having weakened from an intensity of nearly 60 m s(-1) only 10 h earlier. Opal was characterized by an asymmetric structure that was likely related to cold front interaction and an associated midlevel southwesterly jet. Roxanne struck Cozumel, Mexico, with sustained surface winds (marine exposure) of 46 s(-1), crossed the Yucatan, and meandered in the southwest Gulf of Mexico for several days. While in the Bay of Campeche, Roxanne's large area of hurricane-force winds disabled a vessel, which lead to the drowning deaths of five oil industry workers. High-resolution wind records are critical to preserving an accurate extreme wind climatology required for assessment of realistic building code risks. Unfortunately, power interruptions to Automated Surface Observing Stations on the U.S. Virgin Islands (St. Croix, St. Thomas) and Destin, Florida, prevented complete wind records of the eyewall passages of Marilyn and Opal, respectively. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP Powell, MD (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Powell, Mark/I-4963-2013 OI Powell, Mark/0000-0002-4890-8945 NR 33 TC 59 Z9 67 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1998 VL 126 IS 5 BP 1259 EP 1273 DI 10.1175/1520-0493(1998)126<1259:SWFOHE>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZL980 UT WOS:000073492800012 ER PT J AU Surgi, N Pan, HL Lord, SJ AF Surgi, N Pan, HL Lord, SJ TI Improvement of the NCEP global model over the tropics: An evaluation of model performance during the 1995 hurricane season SO MONTHLY WEATHER REVIEW LA English DT Article ID RANGE FORECAST MODEL; SYSTEM; NMC AB An evaluation of the performance of the National Centers for Environmental Prediction Medium-Range Forecast Model was made for the large-scale tropical forecasts and hurricane track Forecasts during the 1995 hurricane season. The assessment of the model was based on changes to the deep convection and planetary boundary layer parameterizations to determine their impact on some of the model deficiencies identified during previous hurricane seasons. Some of the deficiencies in the hurricane forecasts included a weakening of the storm circulation with time that seriously degraded the track Forecasts. In the larger-scale forecasts, an upper-level easterly wind bias was identified in association:vith the failure of the model to maintain the midoceanic upper-tropical upper-tropospheric trough. An overall modest improvement is shown in the large-scale upper-level tropical winds from root-mean-square error calculations. Within a diagnostic framework, an improved simulation of the midoceanic tropical trough has contributed to a better forecast of the upper-level westerly flow. In the hurricane forecasts, enhanced diabatic heating in the model vortex has significantly improved the vertical structure of the forecast storm. This is shown to contribute to a substantial improvement in the track forecasts. C1 NOAA, NWS, NHC, Trop Predict Ctr, Miami, FL 33165 USA. NCEP, Environm Modeling Ctr, Washington, DC USA. RP Surgi, N (reprint author), NOAA, NWS, NHC, Trop Predict Ctr, 11691 SW 17th St, Miami, FL 33165 USA. NR 21 TC 22 Z9 22 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1998 VL 126 IS 5 BP 1287 EP 1305 DI 10.1175/1520-0493(1998)126<1287:IOTNGM>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZL980 UT WOS:000073492800014 ER PT J AU Kurihara, Y Tuleya, RE Bender, MA AF Kurihara, Y Tuleya, RE Bender, MA TI The GFDL hurricane prediction system and its performance in the 1995 hurricane season SO MONTHLY WEATHER REVIEW LA English DT Article ID OPEN LATERAL BOUNDARY; NUMERICAL-SIMULATION; TROPICAL CYCLONES; MODEL; SCHEME; IMPROVEMENTS; SURFACE; TREAT AB The Geophysical Fluid Dynamics Laboratory (GFDL) Hurricane Prediction System was adopted by the U.S. National Weather Service as an operational hurricane prediction model in the 1995 hurricane season. The framework of the prediction model is described with emphasis on its unique features. The model uses a multiply nested movable mesh system to depict the interior structure of tropical cyclones. For cumulus parameterization, a soft moist convective adjustment scheme is used. The model initial condition is defined through a method of vortex replacement. It involves generation of a realistic hurricane vortex by a scheme of controlled spinup. Time integration of the model is carried out by a two-step iterative method that has a characteristic of frequency-selective damping. The outline of the prediction system is presented and the system performance in the 1995 hurricane season is briefly summarized. Both in the Atlantic and the eastern Pacific, the average track forecast errors are substantially reduced by the GFDL model, compared with forecasts by other models, particularly for the forecast periods beyond 36 h. Forecasts of Hurricane Luis and Hurricane Marilyn were especially skillful. A forecast bias is noticed in cases of Hurricane Opal and other storms in the Gulf of Mexico. The importance of accurate initial conditions, in both the environmental flow and the storm structure, is argued. C1 Princeton Univ, Geophys Fluid Dynam Lab, NOAA, Princeton, NJ 08542 USA. RP Kurihara, Y (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, NOAA, Forrestal Campus,US Route 1,POB 308, Princeton, NJ 08542 USA. NR 31 TC 139 Z9 141 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1998 VL 126 IS 5 BP 1306 EP 1322 DI 10.1175/1520-0493(1998)126<1306:TGHPSA>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZL980 UT WOS:000073492800015 ER PT J AU Wenz, HM Ramachandra, S O'Connell, CD Atha, DH AF Wenz, HM Ramachandra, S O'Connell, CD Atha, DH TI Identification of known p53 point mutations by capillary electrophoresis using unique mobility profiles in a blinded study SO MUTATION RESEARCH-GENOMICS LA English DT Article DE DNA; p53 mutation detection; capillary electrophoresis; SSCP ID CONFORMATION POLYMORPHISM; ZONE ELECTROPHORESIS; DNA FRAGMENTS; GENE AB This study is part of an ongoing project at the National Institute of Standards and Technology (NIST) that generates a panel of DNA clones containing the most common mutations found in the human p53 tumor suppressor gene. This panel will be made available as a reference source for evaluation and testing for p53 mutations. Single strand conformation polymorphism (SSCP) analysis has found widespread acceptance as a tool for simply and rapidly screening for mutations, albeit with a detection rate that can be below 100%. We have begun to analyze mutations found in exon 7 of the p53 gene by SSCP using laser induced fluorescence capillary electrophoresis (LIF-CE). PCR fragments: containing single point mutations, were amplified from genomic DNA isolated from cell lines using primers labeled with two different fluorophores. This dual labeling approach allowed better traceability of mobility shifts as a function of the experimental conditions. While analyzing the clones H596, Colo320, Namalwa and wild type (reference samples) at different temperatures, ranging from 25 to 45 degrees C, it was observed that each mutation responded in a unique way to changes in temperature both in magnitude and direction of shifts relative to the wild type sample. In a blinded study, ten p53 exon 7 samples were matched automatically, using ABI PRISM Genotyper(R) software, against the four reference samples. From these 10 samples, six were correctly identified as containing one of the reference mutations, two corresponded to wild type, and two were correctly identified as non-reference mutations. This approach should prove helpful in the rapid screening of target sequences that are known to bear a limited number of mutations. (C) 1998 Elsevier Science B.V. All rights reserved. C1 PE Appl Biosyst, Foster City, CA 94404 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Wenz, HM (reprint author), PE Appl Biosyst, 850 Lincoln Ctr Dr, Foster City, CA 94404 USA. NR 28 TC 31 Z9 32 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1383-5726 J9 MUTAT RES-GENOMICS JI Mutat. Res.-Genomics PD MAY PY 1998 VL 382 IS 3-4 BP 121 EP 132 DI 10.1016/S1383-5726(98)00004-1 PG 12 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 128LN UT WOS:000076407900008 PM 9691993 ER PT J AU Livne, Z Munitz, A Rawers, JC Fields, RJ AF Livne, Z Munitz, A Rawers, JC Fields, RJ TI Consolidation of nanoscale iron powders SO NANOSTRUCTURED MATERIALS LA English DT Article ID NANOCRYSTALLINE MATERIALS; COMPACTION; ALLOYS AB The consolidation behavior of two types of nanoscale iron powders- vacuum condensed (nanograins in nanoparticles) and ball-nulled (nanograins BI microparticles), was studied. The consolidation of two microscale powders, atomized and ground, was also characterized for comparison. Consolidation techniques investigated were cold closed die-compaction, cold isostatic pressing (CIPing), and after CIPing, sintering or hot isostatic pressing (HIPing). The mechanical properties, density, and microstructure of the resulting compacts were found to depend on the original powder type and its consolidation history. Significant differences were found between the microscale and nanoscale powders. AII additional reason, besides the dissimilarity in grain size, for the differences observed relates to the fact that the nanograin powders contained! significant amounts of oxygen, which ultimately resulted in a distinctly two-phase bulk microstructure. The vacuum condensed powder achieved satisfactory green strength on CIPing, and high hardness (440 H-V) oil low temperature sintering. While unnecessary for complete consolidation, HIPing at 500 degrees C was found to be beneficial and compacts of this powder thus tl-eared were found to have a hardness of 520 Hv and high compressive yield strength (1800 MPa). For ball-milled powders, HIPing was found to be essential for achieving effective consolidation: ball-milled material, which remained friable after CIPing and sintering at 580 degrees C, achieved exceptionally high hardness (820 H-V) when HIPed at 580 degrees C and 175 MPa. The ductility was greatly improved when HIPed at temperatures between 700 degrees C and 850 degrees C, while preserving its relatively high strength. The behavior of these nanoscale powders can be understood by invoking the usual densification, particle bonding, and grain growth mechanisms. Optimization of these processes may result in unique mechanical properties of ball milled powders. (C) 1998 Acta Metallurgica Inc. C1 Nucl Res Ctr Negev, IL-84190 Beer Sheva, Israel. US Dept Energy, Albany, OR 97321 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Livne, Z (reprint author), Nucl Res Ctr Negev, POB 9001, IL-84190 Beer Sheva, Israel. NR 15 TC 20 Z9 21 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD MAY PY 1998 VL 10 IS 4 BP 503 EP 522 DI 10.1016/S0965-9773(98)00094-4 PG 20 WC Materials Science, Multidisciplinary SC Materials Science GA 116QF UT WOS:000075735500001 ER PT J AU McCabe, GT Hinton, SA Emmett, RL AF McCabe, GT Hinton, SA Emmett, RL TI Benthic invertebrates and sediment characteristics in a shallow navigation channel of the lower Columbia River, before and after dredging SO NORTHWEST SCIENCE LA English DT Article ID ESTUARY AB Little is known about the impact of dredging on benthic invertebrates in navigation channels of the lower Columbia River. To help fill this informational void, we conducted benthic invertebrate and sediment studies in a shallow navigation channel in the river before and after dredging. Benthic invertebrate and sediment samples were collected with a 0.1-m(2) Van Veen grab sampler at seven stations in the Wahkiakum County Ferry Channel, Washington (River Kilometer 70), and at an upstream reference area in 1993-1995. No significant effects (P > 0.05) of the ferry channel dredging project on Corbicula fluminea, Ceratopogonidae larvae, Corophium spp., or total benthic invertebrate densities were detected in the statistical analysis, although benthic invertebrate densities were significantly different (P < 0.05) between surveys and areas for some organisms. During all eight surveys, Corbicula fluminea, Corophium spp., and Ceratopogonidae (Diptera) larvae were generally the most common benthic invertebrates in both the ferry channel and the reference area. Two measures of community structure, Diversity (H) and Equitability (E), were calculated for each area for each survey. No significant effects (P > 0.05) of the ferry channel dredging project on the benthic invertebrate community structure, as measured by H and E, were detected. No significant effects (P > 0.05) of the ferry channel dredging project on sediment median grain size or percent volatile solids were detected. Results from this study will provide information to aquatic resource agencies that assess the potential environmental effects of dredging in similar habitats of the lower Columbia River. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fish Ecol Div, Seattle, WA 98112 USA. RP McCabe, GT (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fish Ecol Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 17 TC 4 Z9 4 U1 0 U2 8 PU NORTHWEST SCIENTIFIC ASSOC PI SEATTLE PA JEFFREY DUDA, USGS, WESTERN FISHERIES RES CTR, 6505 NE 65 ST, SEATTLE, WA 98115 USA SN 0029-344X EI 2161-9859 J9 NORTHWEST SCI JI Northwest Sci. PD MAY PY 1998 VL 72 IS 2 BP 116 EP 126 PG 11 WC Ecology SC Environmental Sciences & Ecology GA ZW590 UT WOS:000074427100010 ER PT J AU Schade, W Osborn, DL Preusser, J Leone, SR AF Schade, W Osborn, DL Preusser, J Leone, SR TI Two-color cross-correlation of fs-laser pulses by two-photon induced photoconductivity for near and far field optical measurements SO OPTICS COMMUNICATIONS LA English DT Article ID HIGH-REPETITION-RATE; PARAMETRIC OSCILLATOR; PROBE; MICROSCOPY AB Two-color two-photon induced photoconductivity in a GaAsP diffusion type photodiode is demonstrated by measuring femtosecond cross-correlation functions for widely separated wavelength pairs of 775 and 1300 nm. Results are obtained for a range of tunable wavelengths and average powers of the incident lasers by measuring the two-photon induced photocurrent as a function of the optical delay between the pulses. The temporal autocorrelation of femtosecond laser pulses in the near-field of a small diameter aluminum coated optical fiber tip is also obtained with the same photodiode method for single colors. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Schade, W (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. EM schadew@jila.colorado.edu RI Osborn, David/A-2627-2009 NR 18 TC 12 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD MAY 1 PY 1998 VL 150 IS 1-6 BP 27 EP 32 DI 10.1016/S0030-4018(98)00031-5 PG 6 WC Optics SC Optics GA ZY157 UT WOS:000074592000006 ER PT J AU Bendersky, LA Bonevich, JE AF Bendersky, LA Bonevich, JE TI Magnetic multilayers as a structural component in a series of BaO : TiO2 : Fe2O3 compounds SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article AB Several new phases in the complex BaO:TiO2:Fe2O3 system have been recently found to contain structures with ordered intergrowth. The intergrowth consists of two slabs, one (P) with a perovskite-like structure, and the other (H type) with a structure related to the Ba12Fe28Ti15O84 phase. Two representative phases, L and M, have been studied by high-resolution transmission electron microscopy and by energy-filtered imaging to analyse their atomic structure and the compositional distribution of Fe, Ti and Ba. Periodic ordering of the P- and H-type slabs was found in which the first are Ba rich and the second Fe rich. The distribution of Ti is relatively uniform. This chemical inhomogeneity is consistent with structural models of the phases proposed by Bendersky et al. in 1997. The high degree of ordering and heterogeneity of Fe suggests that these materials can be considered as natural 'self-assembled' magnetic multilayers with crystallographically flat interfaces. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Bendersky, LA (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 6 TC 6 Z9 6 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD MAY PY 1998 VL 77 IS 5 BP 279 EP 287 DI 10.1080/095008398178435 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA ZL494 UT WOS:000073438900008 ER PT J AU Suominen, KA Band, YB Tuvi, I Burnett, K Julienne, PS AF Suominen, KA Band, YB Tuvi, I Burnett, K Julienne, PS TI Quantum and semiclassical calculations of cold-atom collisions in light fields SO PHYSICAL REVIEW A LA English DT Article ID LASER-COOLED ATOMS; MATRIX-METHODS; OPTICAL TRAPS; STATE; HALF AB We derive and apply an optical Bloch equation (OBE) model for describing collisions of ground and excited laser cooled alkali atoms in the presence of near-resonant light. Typically these collisions lead to loss of atoms from traps. We compare the results obtained with a quantum mechanical complex potential treatment, semiclassical Landau-Zener models with decay, and a quantum time-dependent Monte Carlo wave packet (MCWP) calculation. We formulate the OBE method in both adiabatic and diabatic representations. We calculate the laser intensity dependence of collision probabilities and find that the adiabatic OBE results agree quantitatively with those of the MCWP calculation, and qualitatively with the semiclassical Landau-Zener model with delayed decay, but that the complex potential method or the traditional Landau-Zener model fail in the saturation limit. C1 Helsinki Inst Phys, FIN-00014 Helsinki, Finland. Univ Helsinki, Dept Phys, Div Theoret Phys, FIN-00014 Helsinki, Finland. Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel. Ben Gurion Univ Negev, Dept Phys, IL-84105 Beer Sheva, Israel. Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Helsinki Inst Phys, PL 9, FIN-00014 Helsinki, Finland. RI Suominen, Kalle-Antti/H-9076-2012; Julienne, Paul/E-9378-2012 OI Suominen, Kalle-Antti/0000-0002-1091-2893; Julienne, Paul/0000-0002-5494-1442 NR 42 TC 27 Z9 27 U1 1 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1998 VL 57 IS 5 BP 3724 EP 3738 DI 10.1103/PhysRevA.57.3724 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZM869 UT WOS:000073584500075 ER PT J AU Morgan, SA Choi, S Burnett, K Edwards, M AF Morgan, SA Choi, S Burnett, K Edwards, M TI Nonlinear mixing of quasiparticles in an inhomogeneous Bose condensate SO PHYSICAL REVIEW A LA English DT Article ID COLLECTIVE EXCITATIONS; EINSTEIN CONDENSATE; GAS AB We use a one-dimensional time-dependent nonlinear Schrodinger equation (NLSE) to study the temporal evolution of excited-state populations of an inhomogeneous Bose condensate. We shaw how one can decompose an arbitrary single-particle wave function into a condensate and a collection of quasiparticles and we use this method to analyze simulations in which the initial wave function contains a finite amount of excitation in a single mode. The nonlinear mixing of the quasiparticles is dominated by processes that approximately conserve energy and we see the reversible transfer of excitation between energetically matched modes. We show analytically how the time scale for nonlinear mixing depends on the amount of initial excitation and the size of the nonlinearity. We propose that, by averaging over the phase of the excitations, the NLSE can be used as a simple tool for the simulation of incoherent excitations. This will allow the techniques presented here to be used to explore finite-temperature mixing effects. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. NIST, Gaithersburg, MD 20899 USA. RP Morgan, SA (reprint author), Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. OI Edwards, Mark/0000-0002-3149-2402 NR 27 TC 53 Z9 54 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 1998 VL 57 IS 5 BP 3818 EP 3829 DI 10.1103/PhysRevA.57.3818 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZM869 UT WOS:000073584500088 ER PT J AU Kim, T Pfister, O Holland, MJ Noh, J Hall, JL AF Kim, T Pfister, O Holland, MJ Noh, J Hall, JL TI Influence of decorrelation on Heisenberg-limited interferometry with quantum correlated photons SO PHYSICAL REVIEW A LA English DT Article ID NOISE; LIGHT; INTERFERENCE; STATES; SU(2) AB The feasibility of a Heisenberg-limited phase measurement using a Mach-Zehnder interferometer fed with twin photon correlated light is investigated theoretically. To take advantage of the Heisenberg limit, 1/N, for the phase sensitivity, one wants thr number of correlated photons, N, to be high. This favors the use of parametric oscillation rather than the weaker but better correlated source given by parametric down-conversion. Ln real systems, decorrelation arising from photon absorption, mode mismatch, and nonideal detectors must be considered. In this paper we address the problem of detection when correlated photons are used as the input. We study the influence of photon statistics and of imperfect quantum correlation elf the input light, and show that it is still possible to break the classical 1/root N phase sensitivity limit in nonideal experimental conditions. AII the results are valid in the general case of quantum correlated bosons. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Ulsan, Dept Phys, Ulsan 680749, South Korea. Inha Univ, Dept Phys, Inchon 402751, South Korea. RP Kim, T (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. RI Pfister, Olivier/A-4924-2013 OI Pfister, Olivier/0000-0003-3386-9661 NR 26 TC 109 Z9 110 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1998 VL 57 IS 5 BP 4004 EP 4013 DI 10.1103/PhysRevA.57.4004 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZM869 UT WOS:000073584500105 ER PT J AU Cai, XY Gurevich, A Tsu, IF Kaiser, DL Babcock, SE Larbalestier, DC AF Cai, XY Gurevich, A Tsu, IF Kaiser, DL Babcock, SE Larbalestier, DC TI Large enhancement of critical-current density due to vortex matching at the periodic facet structure in YBa2Cu3O7-delta bicrystals SO PHYSICAL REVIEW B LA English DT Article ID T-C SUPERCONDUCTORS; GRAIN-BOUNDARIES; JOSEPHSON-JUNCTIONS; TRANSPORT-PROPERTIES; MAGNETIC-FIELD; PENETRATION; NETWORK; DEFECTS; MODEL AB We observed pronounced peaks in the critical-current density J(b)(B) versus applied magnetic field B in YBa2Cu3O7-delta bicrystals well above the lower critical field. These peaks correspond to the fields for which the spacing between intragrain vortices is commensurate with the wavelength of the periodic grain boundary facet structure observed in the same bicrystals. The peaks were observed on a group of grain boundaries that were isolated from four bulk [001]-tilt bicrystals with misorientation angles around 15 degrees, which lie In the transition region from strong to weak coupling. The matching effect provides direct evidence that faceting strongly modulates the coupling strength of grain boundaries and can substantially increase J(b)(B) in high magnetic fields. Periodic modulation of the intergrain coupling by the strain fields observed at the facet junctions by transmission electron microscopy is proposed as the origin of the J(c)(B) enhancement. [S0163-1829(98)07917-X]. C1 Univ Wisconsin, Ctr Appl Superconduct, Madison, WI 53706 USA. Seagate Technol, Bloomington, MN 55435 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Cai, XY (reprint author), Univ Wisconsin, Ctr Appl Superconduct, 1500 Johnson Dr, Madison, WI 53706 USA. RI Larbalestier, David/B-2277-2008; Gurevich, Alex/A-4327-2008 OI Larbalestier, David/0000-0001-7098-7208; Gurevich, Alex/0000-0003-0759-8941 NR 36 TC 38 Z9 39 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10951 EP 10958 DI 10.1103/PhysRevB.57.10951 PG 8 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500111 ER PT J AU Hauer, B Hempelmann, R Udovic, TJ Rush, JJ Jansen, E Kockelmann, W Schafer, W Richter, D AF Hauer, B Hempelmann, R Udovic, TJ Rush, JJ Jansen, E Kockelmann, W Schafer, W Richter, D TI Neutron-scattering studies on the vibrational excitations and the structure of ordered niobium hydrides: The epsilon phase SO PHYSICAL REVIEW B LA English DT Article ID TEMPERATURE-DEPENDENCE; METAL-HYDRIDES; LOCAL MODES; HYDROGEN; NB; TA AB Inelastic and elastic neutron-scattering techniques have been used to study the structure and optical hydrogen vibrations of the ordered niobium hydrides NbHx in the concentration range 0.1 3 Pa), where the plasma oscillation method yields electron densities of up to a factor of two higher than the Langmuir probe results. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Schwabedissen, A (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 49 TC 41 Z9 41 U1 1 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD MAY PY 1998 VL 7 IS 2 BP 119 EP 129 DI 10.1088/0963-0252/7/2/005 PG 11 WC Physics, Fluids & Plasmas SC Physics GA ZT125 UT WOS:000074050900004 ER PT J AU McKnight, ME Martin, JW AF McKnight, ME Martin, JW TI Advanced methods and models for describing coating appearance SO PROGRESS IN ORGANIC COATINGS LA English DT Article; Proceedings Paper CT 23rd International Conference in Organic Coatings: Waterborne, High Solids and Powdered Coatings CY JUL 07-11, 1997 CL ATHENS, GREECE DE coating appearance; metrology; mathematical modeling; computer rendering ID ATOMIC-FORCE MICROSCOPY; PAINT FILMS; PIGMENT DISPERSION; SURFACE-STRUCTURE; GLOSS; SIZE AB The National Institute of Standards and Technology has recently initiated a study to advance appearance met ology. A systems approach which applies technological advances in optical metrology, mathematical modeling, and computer rendering to the development of new methods of appearance characterization and to more accurate methods of modeling the appearance of coatings and coated objects will be used. Corresponding experimental and modeling research activities will be conducted in four areas: coating composition, microstructure of coating films, reflectance properties, and appearance descriptions. The parameterized mathematical models and computer rendering, when coupled with advanced measurements, will support the capability of researchers and engineers to assess the contribution of coating constituents to appearance and help design coatings with appropriate initial appearance and durability properties. This paper presents an overview of the planned research. Published by Elsevier Science S.A. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP McKnight, ME (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 37 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0300-9440 J9 PROG ORG COAT JI Prog. Org. Coat. PD MAY-AUG PY 1998 VL 34 IS 1-4 BP 152 EP 159 PG 8 WC Chemistry, Applied; Materials Science, Coatings & Films SC Chemistry; Materials Science GA 113HF UT WOS:000075544200019 ER PT J AU Almog, O Benhar, I Vasmatzis, G Tordova, M Lee, B Pastan, I Gilliland, GL AF Almog, O Benhar, I Vasmatzis, G Tordova, M Lee, B Pastan, I Gilliland, GL TI Crystal structure of the disulfide-stabilized Fv fragment of anticancer antibody B1: Conformational influence of an engineered disulfide bond SO PROTEINS-STRUCTURE FUNCTION AND GENETICS LA English DT Article DE antibody; antitumor; single chain Fv; variable domains; X-ray crystallography; protein structure; protein stability ID SINGLE-CHAIN ANTIBODY; RECOMBINANT IMMUNOTOXIN; ANTIGEN-BINDING; NUDE-MICE; PROTEIN; CRYSTALLIZATION; IMMUNOGLOBULIN; EXPRESSION; COMPLEX; FAB AB A recombinant Fv construct of the B1 monoclonal antibody that recognizes the Lewis(Y)-related carbohydrate epitope on human carcinoma cells has been prepared, The Fv is composed of the polypeptide chains of the V-H and V-L domains expressed independently and isolated as inclusion bodies. The Fv is prepared by combining and refolding equimolar amounts of guanidine chloride solubilized inclusion bodies. The Fv is stabilized by an engineered interchain disulfide bridge between residues V(L)100 and V(H)44. This construct has a similar binding affinity as that of the single-chain construct (Benhar and Pastan, Clin. Cancer Res. 1:1023-1029, 1995). The B1 disulfide-stabilized Fv (B1dsFv) crystallizes in space group P6(1)22 with the unit cell parameters a = b = 80.1 Angstrom, and c = 138.1 Angstrom. The crystal structure of the B1dsFv has been determined at 2.1-Angstrom resolution using the molecular replacement technique, The final structure has a crystallographic R-value of 0.187 with a root mean square deviation in bond distance of 0.014 Angstrom and in bond angle of 2.74 degrees, Comparisons of the B1dsFv structure with known structures of Fv regions of other immunoglobulin fragments shows closely related secondary and tertiary structures. The antigen combining site of B1dsFv is a deep depression 10-Angstrom wide and 17-Angstrom long with the walls of the depression composed of residues, many of which are tyrosines, from complementarity determining regions L1, L3, H1, H2, and H3. Model building studies indicate that the Lewis(Y) tetrasaccharide, Fuc-Gal-Nag-Fuc, can be accommodated in the antigen combining site in a manner consistent with the epitope predicted in earlier biochemical studies (Pastan, Lovelace, Gallo, Rutherford, Magnani, and Willingham, Cancer Res. 51:3781-3787, 1991). Thus, the engineered disulfide bridge appears to cause little, if any, distortion in the Fv structure, making it an effective substitute for the B1 Fab, Proteins 31:128-138, 1998. (C) 1998 Wiley-Liss, Inc.dagger C1 Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Rockville, MD USA. Tel Aviv Univ, George S Wise Fac Life Sci, Dept Mol Microbiol & Biotechnol, IL-69978 Tel Aviv, Israel. NCI, Mol Biol Lab, Div Basic Sci, NIH, Bethesda, MD 20892 USA. RP Gilliland, GL (reprint author), Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. RI Lee, Byungkook/E-4564-2011 OI Lee, Byungkook/0000-0002-3339-4582 NR 39 TC 13 Z9 13 U1 0 U2 6 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-3585 J9 PROTEINS JI Proteins PD MAY 1 PY 1998 VL 31 IS 2 BP 128 EP 138 DI 10.1002/(SICI)1097-0134(19980501)31:2<128::AID-PROT3>3.0.CO;2-I PG 11 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA ZJ661 UT WOS:000073239400003 PM 9593187 ER PT J AU Stewart, RE Szeto, KK Reinking, RF Clough, SA Ballard, SP AF Stewart, RE Szeto, KK Reinking, RF Clough, SA Ballard, SP TI Midlatitude cyclonic cloud systems and their features affecting large scales and climate SO REVIEWS OF GEOPHYSICS LA English DT Review ID GENERAL-CIRCULATION MODEL; MID-LATITUDE CYCLONES; COAST WINTER STORMS; EXTRATROPICAL MARINE CYCLONE; MOIST POTENTIAL VORTICITY; SUPERCOOLED LIQUID WATER; MICROSCALE STRUCTURE; MESOSCALE STRUCTURE; CIRRUS CLOUDS; COLD-FRONT AB Midlatitude cyclonic cloud systems are common occurrences that significantly impact our climate. In this review, attention is paid to those physical characteristics of these cloud systems with large-scale impacts that must be accounted for in climate simulations. Such attributes include atmospheric forcing, internal structure, surface influences, cloud layering, microphysics, precipitation, water cycling, and radiation. Because of their present limitations associated with, for example, grid sizes and simplified parameterizations, climate models cannot account for all the crucial impacts of these cloud systems. Future advances in the representation of these systems within climate models will need to rely in part on rigorous assessments of model capabilities in a variety of conditions. C1 Atmospher Environm Serv, Downsview, ON M3H 5T4, Canada. UK Meteorol Off, Bracknell RG12 2SZ, Berks, England. Univ Reading, Joint Ctr Mesoscale Meteorol, Reading RG6 6BB, Berks, England. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Atmospher Environm Serv, 4905 Dufferin St, Downsview, ON M3H 5T4, Canada. EM ron.stewart@ec.gc.ca NR 202 TC 23 Z9 23 U1 2 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 8755-1209 EI 1944-9208 J9 REV GEOPHYS JI Rev. Geophys. PD MAY PY 1998 VL 36 IS 2 BP 245 EP 273 DI 10.1029/97RG03573 PG 29 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 126CW UT WOS:000076276200004 ER PT J AU Martin, DM AF Martin, DM TI High technology coral reef monitoring station in Cayos Cochinos SO REVISTA DE BIOLOGIA TROPICAL LA English DT Article C1 NOAA, Natl Ocean Serv, Silver Spring, MD 20910 USA. RP Martin, DM (reprint author), NOAA, Natl Ocean Serv, 1315 EW Highway, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU REVISTA DE BIOLOGIA TROPICAL PI SAN JOSE PA UNIVERSIDAD DE COSTA RICA CIUDAD UNIVERSITARIA, SAN JOSE, COSTA RICA SN 0034-7744 J9 REV BIOL TROP JI Rev. Biol. Trop. PD MAY PY 1998 VL 46 SU 4 BP 199 EP 200 PG 2 WC Biology SC Life Sciences & Biomedicine - Other Topics GA ZQ434 UT WOS:000073861300019 ER PT J AU Arkoosh, MR Casillas, E Huffman, P Clemons, E Evered, J Stein, JE Varanasi, U AF Arkoosh, MR Casillas, E Huffman, P Clemons, E Evered, J Stein, JE Varanasi, U TI Increased susceptibility of juvenile chinook salmon from a contaminated estuary to Vibrio anguillarum SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID HEMATOPOIETIC NECROSIS VIRUS; ONCORHYNCHUS-TSHAWYTSCHA; GAIRDNERI RICHARDSON; RAINBOW-TROUT; POLYCHLORINATED-BIPHENYLS; YERSINIA-RUCKERI; PUGET-SOUND; EXPOSURE; WASHINGTON; INFECTION AB Previous studies have shown that juvenile chinook salmon Oncorhynchus tshawytscha from a contaminated estuary of Puget Sound, Washington, are immunosuppressed. Immunosuppressed fish may be more susceptible to disease and ultimately experience an increase in mortality. To evaluate this possibility, differences in susceptibility to a marine pathogen in outmigrating juvenile chinook salmon from an urban estuary and a nonurban estuary in Puget Sound were assessed. Juvenile chinook salmon were sampled from hatcheries before their release and subsequently from their respective estuaries as the population outmigrated from freshwater to the saltwater environment during the springs of 1993 and 1994. The study was repeated during a 3-month period to assess the duration of the effect after the fish were removed from the source of contaminants and was replicated during a 2-year period to examine interannual variation. Bile, liver, and stomach contents were collected from fish after capture to determine exposure to organic chemical pollutants. Examination of these tissues demonstrated that juvenile salmon from the urban estuary were exposed to higher concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls than juveniles from the nonurban estuary or hatcheries. Juvenile salmon were challenged with serial doses of a marine pathogen, Vibrio anguillarum (serotype 1575), and mortality was measured daily for 7 d. In both years, salmon from the urban estuary challenged with V. anguillarum exhibited a higher cumulative mortality after exposure to the pathogen than salmon from the hatcheries or the nonurban estuary. Our results together with our previous findings support the hypothesis that contaminant-associated immunodysfunction in juvenile chinook salmon may lead to increased susceptibility to infection by a virulent marine bacterium. C1 Natl Ocean & Atmospher Adm, Environm Conservat Div, NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Newport, OR 97365 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. US Fish & Wildlife Serv, Olympia Fish Hlth Ctr, Olympia, WA 98501 USA. RP Arkoosh, MR (reprint author), Natl Ocean & Atmospher Adm, Environm Conservat Div, NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, 2030 S Marine Sci Dr, Newport, OR 97365 USA. NR 48 TC 57 Z9 62 U1 0 U2 9 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 1998 VL 127 IS 3 BP 360 EP 374 DI 10.1577/1548-8659(1998)127<0360:ISOJCS>2.0.CO;2 PG 15 WC Fisheries SC Fisheries GA 105GR UT WOS:000075064800002 ER PT J AU Johnson, LL Misitano, D Sol, SY Nelson, GM French, B Ylitalo, GM Hom, T AF Johnson, LL Misitano, D Sol, SY Nelson, GM French, B Ylitalo, GM Hom, T TI Contaminant effects on ovarian development and spawning success in rock sole from Puget Sound, Washington SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID PAROPHRYS-VETULUS GIRARD; REPRODUCTIVE SUCCESS; WINTER FLOUNDER; POLYCHLORINATED-BIPHENYLS; PSEUDOPLEURONECTES-AMERICANUS; BENTHIC FISH; BIOINDICATORS; STIMULATION; CHEMISTRY; SEDIMENTS AB The objective of this study was to determine if exposure to aromatic hydrocarbons (AHs) or polychlorinated biphenyls (PCBs) was associated with altered ovarian development or reduced spawning success in rock sole Pleuronectes bilineatus. This objective was addressed in two separate phases. In the first study, concentrations of AHs and PCB s were measured in individual fish from four sites in Puget Sound, Washington (Eagle Harbor, Sinclair Inlet, Yukon Harbor, and Pilot Point) with different levels of AH and PCB contamination in sediments and their ovarian development was monitored during the 1989-1991 spawning seasons. In these fish, egg weight was negatively correlated with levels of PCBs in the liver. However, contaminant exposure levels were not significantly associated with the probability of entering vitellogenesis or with gonadosomatic index, plasma estradiol concentrations, or fecundity. In the second study, gravid female soles were taken from Eagle Harbor. Sinclair Inlet, Yukon Harbor, and University Point (known spawning areas for rock soles), and hormonally induced to spawn in the laboratory. Eggs were fertilized with pooled sperm from reference males. Consistent with the first study's findings, fish from Sinclair Inlet, where sediments contain elevated concentrations of PCBs, produced eggs with significantly reduced weight. Furthermore, the overall spawning success of fish from the site with the highest level of AH contamination (Eagle Harbor) was significantly impaired. These findings suggest that environmental exposure to AHs and PCBs may reduce reproductive success in female rock soles, but this species appears to be more resistant to such effects than other Puget Sound flatfish species, such as the English sole Pleuronectes vetulus. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Johnson, LL (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM lyndal.l.johnson@noaa.gov NR 66 TC 20 Z9 20 U1 0 U2 8 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 1998 VL 127 IS 3 BP 375 EP 392 DI 10.1577/1548-8659(1998)127<0375:CEOODA>2.0.CO;2 PG 18 WC Fisheries SC Fisheries GA 105GR UT WOS:000075064800003 ER PT J AU Cline, DW Bales, RC Dozier, J AF Cline, DW Bales, RC Dozier, J TI Estimating the spatial distribution of snow in mountain basins using remote sensing and energy balance modeling SO WATER RESOURCES RESEARCH LA English DT Article ID LANDSAT THEMATIC MAPPER; SIERRA-NEVADA; RADIATION; COVER; TERRAIN AB We present a modeling approach that couples information about snow cover duration from remote sensing with a distributed energy balance model to calculate the spatial distribution of snow water equivalence (SWE) in a 1.2 km(2) mountain basin at the peak of the accumulation season. In situ measurements of incident solar radiation, incident longwave radiation, air temperature, relative humidity, and wind speed were distributed around the basin on the basis of topography. Snow surface albedo was assumed to be spatially constant and to decrease with time. Distributed snow surface temperature was estimated as a function of modeled air temperature. We computed the energy balance for each pixel at hourly intervals using the estimated radiative fluxes and bulk-aerodynamic turbulent-energy flux algorithms from a snowpack energy and mass balance model. Fractional snow cover within each pixel was estimated from three multispectral images (Landsat thematic mapper), one at peak accumulation and two during snowmelt, using decision trees and a spectral mixture model; from these we computed snow cover duration at subpixel resolution. The total cumulative energy for snowmelt at each remote sensing date was weighted by the fraction of each pixel's area that lost its snow cover by that date to determine an initial SWE for each pixel. We tested the modeling approach in the well-studied Emerald Lake basin in the southern Sierra Nevada. With no parameter fitting the modeled spatial pattern of SWE and the mean basin SWE agreed with intensive field survey data. As the modeling approach requires only a remote sensing time series and an ability to estimate the energy balance over the model domain, it should prove useful for computing SWE distributions at peak accumulation over larger areas, where extensive field measurements of SWE are not practical. C1 Natl Weather Serv, Natl Operat Hydrol Remote Sensing Ctr, Off Hydrol, Chanhassen, MN 55317 USA. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. Univ Calif Santa Barbara, Donald Bren Sch Environm Sci & Management, Santa Barbara, CA 93106 USA. RP Cline, DW (reprint author), Natl Weather Serv, Natl Operat Hydrol Remote Sensing Ctr, Off Hydrol, 1735 Lake Dr W, Chanhassen, MN 55317 USA. RI Dozier, Jeff/B-7364-2009 OI Dozier, Jeff/0000-0001-8542-431X NR 28 TC 109 Z9 113 U1 2 U2 33 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 1998 VL 34 IS 5 BP 1275 EP 1285 DI 10.1029/97WR03755 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA ZL188 UT WOS:000073407600027 ER PT J AU Schwarz, FP Ahmed, H Bianchet, MA Amzel, LM Vasta, GR AF Schwarz, FP Ahmed, H Bianchet, MA Amzel, LM Vasta, GR TI Thermodynamics of bovine spleen galectin-1 binding to disaccharides: Correlation with structure and its effect on oligomerization at the denaturation temperature SO BIOCHEMISTRY LA English DT Article ID CARBOHYDRATE-RECOGNITION DOMAINS; THERMAL-DENATURATION; CONCANAVALIN-A; ANIMAL LECTINS; PROTEIN; SPECIFICITY; ENERGETICS; MONOSACCHARIDE; FAMILY; LUNG AB Isothermal titration calorimetry (ITC) measurements of the binding 1-beta-carbohydrate-substituted galactopyranoside derivatives to galectin-1 from bovine spleen, a dimer with one binding site per subunit, were performed at 283-285 and 298 K. The disaccharides were lactose, methyl beta-lactoside, lactulose, 4-O-beta-D-galactopyranosyl-D-mannopyranoside, 3-O-beta-D-galactopyranosyl-D-arabinose, 2'-O-methyllactose, lacto-N-biose, N-acetyllactosamine, and thiodigalactopyranoside. The site binding enthalpies, Delta H-b, are the same at both temperatures and range from -42.2 +/- 3.3 kJ mol(-1) for thiodigalactopyranoside to -24.5 +/- 0.5 kJ mol(-1) for lacto-N-biose, and the site binding constants range from 4.86 +/- 0.78 x 10(3) M-1 for methyl beta-lactoside at 297.8 K to 6.54 +/- 0.97 x 10(4) M-1 for N-acetyllactosamine at 281.3 K. The binding reactions are enthalpically driven, exhibit enthalpy-entropy compensation, and, with the exception of N-acetyllactosamine, follow a van't Hoff dependence of the binding constant on temperature. The number of contacts at distances <4.0 Angstrom between the disaccharide and galectin was determined from the energy-minimized conformation of the complex derived from the X-ray crystallographic structure of the galectin-N-acetyllactosamine complex determined by Liao et al. [Liao, D. I., Kapadia, G., Ahmed, H., Vasta, G. R., and Herzberg, O. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 1428-1432]. The binding enthalpies calculated from changes in the solvent-accessible surface areas of the galectin binding site upon binding of the disaccharide were in close agreement with the experimental values for lactose, lactulose, lacto-N-biose, and N-acetyllactosamine, ail of which exhibit binding enthalpies >-36 kJ mol(-1). Differential scanning calorimetry measurements on solutions of galectin and its disaccharide complexes show that the galectin dimer does not dissociate upon denaturation in contrast to the legume lectins. At the denaturation temperature, the galectin in the absence of sugar exists as a tetramer, and the extent of this association is substantially reduced in the presence of a disaccharide. C1 Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Rockville, MD 20850 USA. Univ Maryland, Inst Biotechnol, Ctr Marine Biotechnol, Columbus Ctr, Baltimore, MD 21202 USA. Johns Hopkins Univ, Sch Med, Dept Biophys & Biophys Chem, Baltimore, MD 21205 USA. RP Schwarz, FP (reprint author), Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. RI Bianchet, Mario/K-2131-2015; OI Bianchet, Mario/0000-0001-9032-7549; Amzel, L. Mario/0000-0002-0129-9572 NR 35 TC 47 Z9 48 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD APR 28 PY 1998 VL 37 IS 17 BP 5867 EP 5877 DI 10.1021/bi9716478 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZL949 UT WOS:000073489700011 PM 9558320 ER PT J AU Mote, PW Dunkerton, TJ McIntyre, ME Ray, EA Haynes, PH Russell, JM AF Mote, PW Dunkerton, TJ McIntyre, ME Ray, EA Haynes, PH Russell, JM TI Vertical velocity, vertical diffusion, and dilution by midlatitude air in the tropical lower stratosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-VAPOR AB Air passing upward through the tropical tropopause is "marked" by an annually varying water vapor mixing ratio much as a tape recorder marks a magnetic tape; as the air ascends in the tropical stratosphere, these marks are effaced by a combination of vertical diffusion within the tropics and dilution of tropical air by sideways (isentropic) mixing-in of midlatitude air. We represent these processes using a one-dimensional advection-diffusion-dilution model, which we inverse-solve for the vertical profiles of three unknowns (vertical advection velocity, vertical diffusion coefficient, and dilution rate coefficient) after prescribing the vertical profiles of time mean methane [CH4] and of amplitude and phase of the annually varying tape recorder signal in 2[CH4]+[H2O]. When tested on synthetic data generated by forward solving the same model, the method for inverse solution proved to be well conditioned and to give accurate results above 18 km. Applying the method to 5 years of smoothed data from the Halogen Occultation Experiment, we find a vertical advection velocity with a minimum of about 0.2 mm s(-1) near 20 km, and both dilution rate coefficient and vertical diffusion coefficient with remarkably low minima near 22 km, 1/(6-7 year) and roughly 0.02 m(2)s(-1), respectively. Our derived profile of vertical advection velocity agrees well, between 18 and 24 km, with an independent, radiatively derived, mass-budget-constrained transformed Eulerian mean calculation. Despite the relatively modest values of the diffusion coefficient, vertical diffusion plays a significant role in attenuating the tape recorder signal, according to our model. The minimum value of the dilution rate coefficient corresponds to a relaxation timescale of 6-7 years, much longer than the timescales found in other studies. The long relaxation timescale at 20-24 km is, however, consistent with (1) the minimum in vertical velocity, (2) a reduced attenuation rate in the tape recorder signal, and (3) a decrease, hitherto unremarked, in the tropical vertical gradient of [CH4] there. C1 NW Res Associates Inc, Bellevue, WA 98009 USA. Univ Cambridge, Dept Appl Math & Theoret Phys, Ctr Atmospher Sci, Cambridge CB3 9EW, England. NOAA, Climate Modeling & Diagnost Lab, Boulder, CO 80303 USA. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Climate Impacts Grp, Seattle, WA 98195 USA. RP Mote, PW (reprint author), NW Res Associates Inc, POB 3027, Bellevue, WA 98009 USA. EM mote@nwra.com RI Ray, Eric/D-5941-2013; OI Ray, Eric/0000-0001-8727-9849; Haynes, Peter/0000-0002-7726-6988 NR 38 TC 107 Z9 108 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 27 PY 1998 VL 103 IS D8 BP 8651 EP 8666 DI 10.1029/98JD00203 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZK155 UT WOS:000073290900003 ER PT J AU Weng, FZ Grody, NC AF Weng, FZ Grody, NC TI Physical retrieval of land surface temperature using the special sensor microwave imager SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HIGH-RESOLUTION RADIOMETER; BRIGHTNESS TEMPERATURES; SOIL-MOISTURE; CLASSIFICATION; WATER; FIFE AB This study developed a physical algorithm for retrieving land surface temperatures (LST) by using the special sensor microwave imager (SSM/I) brightness temperature measurements at 19.35 and 22.23 GHz. A nonlinear algebraic equation is obtained for the LST and is solved through the Newtonian iterative procedure. The technique does not require any surface classification because the surface emissivity variations are essentially eliminated by using two closely spaced channels. In addition, the algorithm is less influenced by ice scattering from precipitation and snow cover because of the use of low frequencies. The retrieval accuracy is first examined using simulated measurements. It is found that the root-mean-square (RMS) error is about 3.8 K, with the largest errors occurring in dry atmospheres having total precipitable water of 5.0 mm or less. The RMS error slightly increases to 4.4 K when the algorithm is applied for the actual SSM/I measurements. Large biases were found for cold temperatures where the atmospheric water vapor content may be very low. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Washington, DC 20233 USA. NOAA, Univ Corp Atmospher Res Sci Visitor Program, Ctr Sci, Washington, DC USA. RP Weng, FZ (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Room 601,E-RA2,4700 Silver Hill Rd,Stop 9910, Washington, DC 20233 USA. EM fweng@nesdis.noaa.gov; ngrody@nesdis.noaa.gov RI Weng, Fuzhong/F-5633-2010 OI Weng, Fuzhong/0000-0003-0150-2179 NR 19 TC 39 Z9 51 U1 1 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 27 PY 1998 VL 103 IS D8 BP 8839 EP 8848 DI 10.1029/98JD00275 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZK155 UT WOS:000073290900018 ER PT J AU Kumar, A Hoerling, MP AF Kumar, A Hoerling, MP TI Specification of regional sea surface temperatures in atmospheric general circulation model simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID EXTRATROPICAL SST ANOMALIES; NORTHERN-HEMISPHERE; GLOBAL TEMPERATURE; VARIABILITY; OCEAN; PACIFIC; CONVECTION; ROLES; CLOUD; ENSO AB A hierarchy of atmospheric general circulation model simulations of the 1950-1994 period that employ different prescriptions of the oceanic boundary conditions are analyzed. It is demonstrated that contrary to expectations, increased spatial coverage of the sea surface temperature specification can degrade the underlying simulated climate signals. The cause for this is related to an inability to accurately model the diversity of air-sea interaction regimes that exist across the global oceans. Such failure is shown to generate spurious sources of atmospheric energy that exert global influences on interannual and decadal timescales. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr, Boulder, CO 80309 USA. NOAA, Natl Ctr Environm Predict, Climate Modeling Branch, Environm Modeling Ctr, Camp Springs, MD 20746 USA. RP Kumar, A (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr, Campus Box 449, Boulder, CO 80309 USA. EM wd01ak@sun10.wwb.noaa.gov; mph@cdc.noaa.gov NR 25 TC 50 Z9 52 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 27 PY 1998 VL 103 IS D8 BP 8901 EP 8907 DI 10.1029/98JD00427 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZK155 UT WOS:000073290900023 ER PT J AU Behar, D Dhanasekaran, T Neta, P Hosten, CM Ejeh, D Hambright, P Fujita, E AF Behar, D Dhanasekaran, T Neta, P Hosten, CM Ejeh, D Hambright, P Fujita, E TI Cobalt porphyrin catalyzed reduction of CO2. Radiation chemical, photochemical, and electrochemical studies SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CARBON-DIOXIDE REDUCTION; ONE-ELECTRON; ELECTROCATALYTIC REDUCTION; AQUEOUS-SOLUTION; HOMOGENEOUS CATALYSIS; 2-ELECTRON REDUCTION; METAL-COMPLEXES; RATE CONSTANTS; MACROCYCLES; TETRAPHENYLPORPHYRIN AB Several cobalt porphyrins (CoP) have been reduced by radiation chemical, photochemical, and electrochemical methods, in aqueous and organic solvents. In aqueous solutions, the (CoP)-P-1 state is stable at high pH but is shorter lived in neutral and acidic solutions. Stable (CoP)-P-1 is also observed in organic solvents and is unreactive toward CO2. One-electron reduction of (CoP)-P-1 leads to formation of a species that is observed as a transient intermediate by pulse radiolysis in aqueous solutions and as a stable product following reduction by Na in tetrahydrofuran solutions. The spectrum of this species is not the characteristic spectrum of a metalloporphyrin pi-radical anion and is ascribed to (CoP)-P-0. This species binds and reduces CO2. Catalytic formation of CO and HCO2- is confirmed by photochemical experiments in acetonitrile solutions containing triethylamine as a reductive quencher. Catalytic reduction of CO2 is also confirmed by cyclic voltammetry in acetonitrile and butyronitrile solutions and is shown to occur at the potential at which (CoP)-P-1 is reduced to (CoP)-P-0. As compared with CoTPP, fluorinated derivatives are reduced, and catalyze CO2 reduction, at less negative potentials. C1 NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Howard Univ, Dept Chem, Washington, DC 20059 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Neta, P (reprint author), NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Fujita, Etsuko/D-8814-2013 NR 50 TC 96 Z9 99 U1 4 U2 81 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 23 PY 1998 VL 102 IS 17 BP 2870 EP 2877 DI 10.1021/jp9807017 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZM100 UT WOS:000073504700018 ER PT J AU Cerrada, ML Perez, E Perena, JM Benavente, R AF Cerrada, ML Perez, E Perena, JM Benavente, R TI Wide-angle X-ray diffraction study of the phase behavior of vinyl alcohol ethylene copolymers SO MACROMOLECULES LA English DT Article ID MORPHOLOGICAL STRUCTURE AB The influence of the composition and thermal history on the type of lattice developed has been studied by wide-angle X-ray diffraction measurements in three vinyl alcohol-ethylene, VAE, copolymers with different compositions, which were crystallized from the melt at various cooling rates. The results are compared with those of the corresponding homopolymers, poly(vinyl alcohol) and low-density polyethylene. Both the composition and the cooling rate have been found to determine the crystalline structure of these VAE copolymers. Thus, for the samples slowly crystallized from the melt, a monoclinic lattice is obtained for copolymers VAE71 and VAE68 (with compositions of 71 and 68 mol % VA, respectively) while an orthorhombic lattice has been found for copolymer VAE56 (56 mol % VA). The effect of the cooling rate is very important, since copolymers VAE71 and VAE68 lead to the orthorhombic form when the samples are quenched from the melt. Copolymer VAE56 has been found to crystallize in an orthorhombic lattice under all the crystallization conditions here studied. The polymorphism exhibited by these copolymers is not the usual case for two different unit cells with well-defined lattice parameters: VAE71 and VAE68 show, by the influence of the cooling rate, a continuous change of some of the lattice constants. For instance, the angle beta of the monoclinic lattice decreases smoothly from an "equilibrium" value of about 92.2 degrees in the slowly crystallized samples to a final value in the quenched samples of 90 degrees (orthorhombic unit cell). The degree of crystallinity determined from the X-ray diffraction patterns has been found to be in the quenched specimens considerably smaller than that in the slowly crystallized samples, standing in contrast to the constancy of the enthalpy of melting. Moreover, it seems that there are no differences in the melting temperatures between the two crystalline modifications. C1 CSIC, Inst Ciencia & Tecnol Polimeros, E-28006 Madrid, Spain. RP Perez, E (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RI CERRADA, MARIA/E-9810-2016; Benavente, Rosario/F-5034-2016; OI CERRADA, MARIA/0000-0003-4261-0627; Benavente, Rosario/0000-0003-0416-0151; Perez, Ernesto/0000-0002-5144-9268 NR 21 TC 57 Z9 57 U1 3 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 21 PY 1998 VL 31 IS 8 BP 2559 EP 2564 DI 10.1021/ma9705127 PG 6 WC Polymer Science SC Polymer Science GA ZK615 UT WOS:000073342900025 ER PT J AU Levicky, R Koneripalli, N Tirrell, M Satija, SK AF Levicky, R Koneripalli, N Tirrell, M Satija, SK TI Stratification in bidisperse polymer brushes from neutron reflectivity SO MACROMOLECULES LA English DT Article ID DENSITY PROFILE; GOOD SOLVENT; TETHERED CHAINS; MONTE-CARLO; LAYERS; COPOLYMERS; MICA AB Two-component (bidisperse) polystyrene brushes, consisting of long and short chain populations end-tethered at a solid/liquid interface, were studied in toluene and cyclohexane solvents using neutron reflection methods. A stratification of the long and short chain components was observed under all solvent conditions, with a maximum in the long chain volume fraction profile occurring at the outer edge of the brush. The short chains resided in the inner brush region nearer to the substrate. Comparison of experimentally derived volume fraction profiles to analytical self-consistent mean-field theory predictions revealed qualitative agreement; however, the experimentally observed stratification is less pronounced. Furthermore, under the poorer, near-Gamma conditions in cyclohexane, the total volume fraction profile was rather featureless and did not exhibit the characteristic bidisperse shape present in toluene. C1 Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Tirrell, M (reprint author), Univ Minnesota, Dept Chem Engn & Mat Sci, 421 Washington Ave SE, Minneapolis, MN 55455 USA. NR 30 TC 25 Z9 26 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 21 PY 1998 VL 31 IS 8 BP 2616 EP 2621 DI 10.1021/ma971278n PG 6 WC Polymer Science SC Polymer Science GA ZK615 UT WOS:000073342900034 ER PT J AU Lafferty, WJ Solodov, AM Lugez, CL Fraser, GT AF Lafferty, WJ Solodov, AM Lugez, CL Fraser, GT TI Rotational line strengths and self-pressure-broadening coefficients for the 1.27-mu m, a (1)Delta(g)-X-3 Sigma(-)(g), v = 0-0 band of O-2 SO APPLIED OPTICS LA English DT Article ID INTENSITY FACTORS; O-2(A(1)DELTA(G)); TRANSITION; DAYGLOW; SPECTRA; OZONE; STATE AB We measured at 296 K the rotational line strengths and pressure-broadening coefficients for the 1.27-mu m, a (1) Delta(g)-X-3 Sigma(g)(-), upsilon = 0-0 band of O-2 with a Fourier transform infrared spectrometer using an optical path length of 84 m, a spectral resolution of 0.01 cm(-1), and sample pressures between 13 and 104 kPa. The integrated band strength is 7.79(17) x 10(-6) m(-2) Pa-1 [7.89(17) x 10(-5) cm(-2) atm(-1)], and the Einstein A coefficient for spontaneous emission is 2.237(51) x 10(-4) s(-1), which corresponds to an upper-state 1/e lifetime of 1.24(3) h. The pressure-broadening coefficients decrease with increasing N and range from 19 to 38 MHz/kPa (FWHM). The mean value for the transitions studied is 30.3(21) MHz/kPa [0.1024(71) cm(-1)/atm] (FWHM). The Einstein A coefficient determined here is in good agreement with the widely accepted value of 2.58 x 10(-4) s(-1) initially obtained by Badger et al. [J. Chem. Phys. 43, 4345 (1965)] more than 30 years ago. The standard uncertainties given above are one standard deviation. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Lafferty, WJ (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 27 TC 75 Z9 76 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 20 PY 1998 VL 37 IS 12 BP 2264 EP 2270 DI 10.1364/AO.37.002264 PG 7 WC Optics SC Optics GA ZH797 UT WOS:000073148600011 PM 18273151 ER PT J AU Sheridan, PJ Norton, RB AF Sheridan, PJ Norton, RB TI Determination of the passing efficiency for aerosol chemical species through a typical aircraft-mounted, diffuser-type aerosol inlet system SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PARTICLE-SIZE DISTRIBUTION; ARCTIC AEROSOLS; AIR AB To assess the particle transmission efficiency of a conventional aircraft-mounted, diffuser-type inlet (CI), a new design inlet containing an internal filter basket assembly (aerosol filter inlet, or AFI) was constructed. All interior surfaces of the AFI were covered with filter material, and air was actively pulled through these filter walls during aerosol sampling. The AFI was demonstrated in the laboratory to trap nearly all particles entering its nozzle orifice, so it was considered usable as a baseline to judge the performance of other inlets. Wind tunnel studies were conducted at three different wind velocities that approximated typical research aircraft speeds. As wind velocity increased, particle transmission through the CI relative to the AFI decreased, as evidenced by chemical analysis of the filter deposits. Aircraft studies of the two inlets showed that particle transmission varied significantly with the measured species. Typical coarse-particle species such as Ca++, Mg++, Na+ and K+ showed 50-90% mass losses through a conventional diffuser-type inlet/curved intake tube system. Predominantly fine particle species such as SO4= and NH4+ passed the CI system with much higher efficiencies, with aerosol mass losses of 0-26% for most flights. Since the AFI traps nearly all particles aspirated into its nozzle orifice, these values indicate that on average, 80-90% of the SO4= and NH4+ aerosol mass passes through the CI and curved intake tube during airborne sampling. This finding suggests that the capability to sample fine (i.e., submicrometer) aerosols from aircraft is perhaps not as bad as has been previously reported, given that adequate attention is paid to inlet design, location, and orientation issues. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Sheridan, PJ (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Campus Box 449, Boulder, CO 80309 USA. EM psheridan@cmdl.noaa.gov; norton@al.noaa.gov NR 27 TC 11 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 20 PY 1998 VL 103 IS D7 BP 8215 EP 8225 DI 10.1029/98JD00286 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZJ026 UT WOS:000073172100001 ER PT J AU Ridley, B Walega, J Hubler, G Montzka, D Atlas, E Hauglustaine, D Grahek, F Lind, J Campos, T Norton, R Greenberg, J Schauffler, S Oltmans, S Whittlestone, S AF Ridley, B Walega, J Hubler, G Montzka, D Atlas, E Hauglustaine, D Grahek, F Lind, J Campos, T Norton, R Greenberg, J Schauffler, S Oltmans, S Whittlestone, S TI Measurements of NOx and PAN and estimates of O-3 production over the seasons during Mauna Loa Observatory Photochemistry Experiment 2 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CONTINENTAL UNITED-STATES; CENTRAL NORTH PACIFIC; LONG-RANGE TRANSPORT; PHOTOSTATIONARY STATE; PEROXYACETYL NITRATE; NITRIC-OXIDE; TROPOSPHERIC OZONE; EQUATORIAL PACIFIC; EASTERN PACIFIC; HNO3/NOX RATIO AB Measurements of peroxyacetyl nitrate (PAN) and NOx and a variety of other constituents were made over approximately 1-month-long intensives in the autumn of 1991 and the winter, spring, and summer of 1992 during the second Mauna Loa Observatory Photochemistry Experiment (MLOPEX 2). PAN and NOx in the free troposphere had maximum abundances in spring in concert with the well-known maximum in O-3. The ratio of the spring to summer averages was a factor of 4.1 for PAN, a factor of 1.6 for O-3, and only a factor of 1.4 for NOx. During most intensives, variations over periods of a few days to a week were often larger than the average seasonal amplitude. In free tropospheric air masses local to Hawaii, average PAN/NOx ratios were a maximum in winter through spring but in the range of 0.25-0.86 in all intensives. PAN decomposition is unlikely to be the major net source of NOx in local air masses in summer and fall. The low HNO3/NOx ratios determined during MLOFEX 1 were confirmed during MLOPEX 2. Intensive average ratios of 1.6-3.8 over the year are lower than some model predictions. Both the low ratio and the magnitude of NOx imply a shortcoming in our understanding of the transformations and sources of NOx. constituents in the central Pacific, The 3- to 4-km altitude region near Hawaii was a net importer of O-3, on average, over the year. The average net rate of production of O-3 in free tropospheric air was near zero in winter, -0.4 to -0.8 ppbv/d in spring, -1.4 ppbv/d in summer, and -0.6 ppbv/d in autumn. Thus the spring maximum in O-3 is not due to local photochemistry. We believe, as has been concluded from the long-term measurements of lone-lived constituents by the Climate Monitoring and Diagnostics Laboratory, that the variation of ozone precursors over the year and on shorter timescales of a few days to a week is controlled predominantly by changes in long-range transport: more frequent sampling of higher-latitude and higher-altitude air masses in winter and spring versus more frequent sampling of well-aged air from lower altitudes and latitudes in summer and autumn. C1 Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. NOAA, Aeron Lab, Boulder, CO 80302 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80302 USA. Australian Nucl Sci & Technol Org, Lucas Heights, NSW, Australia. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Ridley, B (reprint author), Natl Ctr Atmospher Res, Div Atmospher Chem, POB 3000, Boulder, CO 80307 USA. EM ridley@acd.ucar.edu; ghubler@al.noaa.gov; rnorton@al.noaa.gov; soltmans@cmdl.noaa.gov RI Hubler, Gerhard/E-9780-2010; Atlas, Elliot/J-8171-2015 NR 68 TC 25 Z9 25 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 20 PY 1998 VL 103 IS D7 BP 8323 EP 8339 DI 10.1029/98JD00075 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZJ026 UT WOS:000073172100011 ER PT J AU Ridley, BA Walega, JG Lamarque, JF Grahek, FE Trainer, M Hubler, G Lin, X Fehsenfeld, FC AF Ridley, BA Walega, JG Lamarque, JF Grahek, FE Trainer, M Hubler, G Lin, X Fehsenfeld, FC TI Measurements of reactive nitrogen and ozone to 5-km altitude in June 1990 over the southeastern United States SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ODD-NITROGEN; RURAL SITE; NOY AB Aircraft flights made in June 1990 substantiate the expected variability of ozone and reactive nitrogen constituents in the lower atmosphere over Mississippi and Alabama due to the variety and proximity of sources and the photochemical production and loss of ozone. Urban, biomass burn, electrical power plant, and paper mill plumes are examples of sources encountered during these flights and some of their characteristics are described. For example, in the urban plume from Mobile, Alabama, an upper limit to the ozone production efficiency was 6-7 parts per billion by volume (ppbv) of O-3 per ppbv of NO, oxidized. Emissions from several biomass fires had lower efficiencies of 2-4 ppbv ppbv(-1), but the average rate of production of ozone was as high as 58 ppbv hr(-1) for one fire where the plume was isolated from mixing to the surface. Close encounters with paper mill and power plant plumes showed chemical consumption of O-3, while far-field encounters with power plant plumes showed enhanced O-3 due to photochemical production. Observations made in early morning, below a nocturnal inversion provide indirect evidence of significant nighttime oxidation of freshly emitted NO, to reservoir constituents. Although statistics for the region covered by these flights clearly depend on precisely where the aircraft flew, the mean and median temporal and vertical behaviors of constituent mixing ratios are summarized. C1 Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Ridley, BA (reprint author), Natl Ctr Atmospher Res, Div Atmospher Chem, POB 3000, Boulder, CO 80307 USA. EM ridley@acd.ucar.edu RI Hubler, Gerhard/E-9780-2010; Trainer, Michael/H-5168-2013; Fehsenfeld, Frederick/I-4876-2013; Lamarque, Jean-Francois/L-2313-2014 OI Lamarque, Jean-Francois/0000-0002-4225-5074 NR 25 TC 14 Z9 15 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 20 PY 1998 VL 103 IS D7 BP 8369 EP 8388 DI 10.1029/97JD03463 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZJ026 UT WOS:000073172100014 ER PT J AU Rusch, DW Randall, CE Callan, MT Horanyi, M Clancy, RT Solomon, SC Oltmans, SJ Johnson, BJ Koehler, U Claude, H De Muer, D AF Rusch, DW Randall, CE Callan, MT Horanyi, M Clancy, RT Solomon, SC Oltmans, SJ Johnson, BJ Koehler, U Claude, H De Muer, D TI A new inversion for stratospheric aerosol and gas experiment II data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OZONE; VALIDATION; INSTRUMENT; ALGORITHM AB `qWe describe a new inversion algorithm for retrieving ozone densities and aerosol extinctions from Stratospheric Aerosol and Gas Experiment (SAGE) II measurements. The primary differences between the new algorithm and the current operational SAGE II inversion are the order of the species and altitude inversions, and the methods used to calculate aerosol extinction and remove saturated signals. Ozone densities retrieved at altitudes from 15 to 30 km using the new algorithm are compared to those from the operational SAGE II inversion, as well as to ozone densities from coincident balloon ozonesonde measurements at four different locations in the northern hemisphere between 1984 and 1991 for low to medium stratospheric aerosol loading conditions. The results of the comparison show that the ozone densities resulting from the operational and new algorithms agree to within 1% above 22 km. Below 22 km, the new results are lower than the operational results by up to 30%, depending on altitude and location. At all four stations the new results agree better with the sondes, decreasing the SAGE II/sonde differences by a factor of 2 or more. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Meteorol Observ, D-82383 Hohenpeissenberg, Germany. Royal Meteorol Soc, B-1180 Brussels, Belgium. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80309 USA. Univ Colorado, Cooperat Inst Res Environm Serv, Boulder, CO 80309 USA. RP Rusch, DW (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. EM david.rusch@lasp.colorado.edu RI Solomon, Stanley/J-4847-2012; Randall, Cora/L-8760-2014; OI Solomon, Stanley/0000-0002-5291-3034; Randall, Cora/0000-0002-4313-4397; Horanyi, Mihaly/0000-0002-5920-9226 NR 14 TC 11 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 20 PY 1998 VL 103 IS D7 BP 8465 EP 8475 DI 10.1029/97JD03625 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZJ026 UT WOS:000073172100021 ER PT J AU Bergeson, SD Balakrishnan, A Baldwin, KGH Lucatorto, TB Marangos, JP McIlrath, TJ O'Brian, TR Rolston, SL Sansonetti, CJ Wen, J Westbrook, N Cheng, CH Eyler, EE AF Bergeson, SD Balakrishnan, A Baldwin, KGH Lucatorto, TB Marangos, JP McIlrath, TJ O'Brian, TR Rolston, SL Sansonetti, CJ Wen, J Westbrook, N Cheng, CH Eyler, EE TI Measurement of the He ground state lamb shift via the two-photon 1(1)S-2(1)S transition SO PHYSICAL REVIEW LETTERS LA English DT Article ID 2-PHOTON SPECTROSCOPY; ENERGY; HELIUM; AMPLIFICATION; HYDROGEN; 58-NM AB We have extended two-photon Doppler-free spectroscopy to the vacuum ultraviolet spectral region, to accurately measure the He 1 S-1-2 S-1 transition at 120 nm. Our result is 4984872315(48) MHz. This yields a ground state Lamb shift of 41104(48) MHz, in fair agreement with theory and other experiments. This approach has the potential for significantly better accuracy once improvements in the laser and the wavelength metrology are implemented. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. RP Bergeson, SD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Baldwin, Kenneth/A-4928-2008; rolston, steven/L-5175-2013; Bergeson, Scott/L-8959-2013 OI Baldwin, Kenneth/0000-0002-2043-5330; rolston, steven/0000-0003-1671-4190; Bergeson, Scott/0000-0002-3124-9226 NR 24 TC 82 Z9 82 U1 1 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 20 PY 1998 VL 80 IS 16 BP 3475 EP 3478 DI 10.1103/PhysRevLett.80.3475 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ325 UT WOS:000073202700014 ER PT J AU Benedict, LX Chopra, NG Cohen, ML Zettl, A Louie, SG Crespi, VH AF Benedict, LX Chopra, NG Cohen, ML Zettl, A Louie, SG Crespi, VH TI Microscopic determination of the interlayer binding energy in graphite SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CARBON NANOTUBES; ENERGETICS; GROWTH AB High-tensile-strength carbon nanotubes an nonetheless susceptible to large radial deformations. In particular, tubes may collapse so that opposing tube walls attain the graphitic interlayer spacing. A simple elastic model shows that the ratio of mean curvature modulus to the interwall attraction of graphite determines the cross-section of a collapsed tube. Transmission electron microscopy of collapsed tubes confirms the elastic model and affords the first microscopic measurement of the strength of the intersheet attraction, a quantity otherwise difficult to assess. (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Penn State Univ, Dept Phys, Davey Lab 104, University Pk, PA 16802 USA. RP Benedict, LX (reprint author), Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Gaithersburg, MD 20878 USA. RI Zettl, Alex/O-4925-2016; OI Zettl, Alex/0000-0001-6330-136X; Crespi, Vincent/0000-0003-3846-3193 NR 22 TC 246 Z9 248 U1 5 U2 38 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 APR 17 PY 1998 VL 286 IS 5-6 BP 490 EP 496 DI 10.1016/S0009-2614(97)01466-8 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZM713 UT WOS:000073568400021 ER PT J AU Tynan, CT AF Tynan, CT TI Ecological importance of the Southern Boundary of the Antarctic Circumpolar Current SO NATURE LA English DT Article ID EUPHAUSIA-SUPERBA; OCEAN; ZONE; STRATIFICATION AB The Southern Ocean surrounds the Antarctic continent and supports one of the most productive marine ecosystems. Migratory and endemic species of whales, seals and birds benefit from the high biomass of their principal prey, krill (Euphausia superba) and cephalopods, in this area. Most species of baleen whales and male sperm whales in the Southern Hemisphere migrate between low-latitude breeding grounds in winter and highly productive Antarctic feeding grounds in summer. Here I show the importance of the southernmost reaches of the strongest ocean current, the Antarctic Circumpolar Current (ACC), to a complex and predictable food web of the Southern Ocean, The circumpolar distributions of blue, fin and humpback whales from spring to midsummer trace the non-uniform high-latitude penetration of shoaled, nutrient-rich Upper Circumpolar Deep Water, which is carried eastward by the ACC, The poleward extent of this water mass delineates the Southern Boundary(1) of the ACC and corresponds not only to the circumpolar distributions of baleen whales, but also to distributions of krill and to regions of high, seasonally averaged, phytoplankton biomass, Sperm whales, which feed on cephalopods(2), also congregate in highest densities near the Southern Boundary. The association of primary production, Krill, and whales with the Southern Boundary, suggests that it provides predictably productive foraging for many species, and is of critical importance to the function of the Southern Ocean ecosystem. C1 NOAA, Natl Res Council, Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Tynan, CT (reprint author), NOAA, Natl Res Council, Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 19 TC 146 Z9 158 U1 2 U2 36 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 16 PY 1998 VL 392 IS 6677 BP 708 EP 710 DI 10.1038/33675 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZH612 UT WOS:000073129000056 ER PT J AU Glazier, SA Campbell, ER Campbell, WH AF Glazier, SA Campbell, ER Campbell, WH TI Construction and characterization of nitrate reductase-based amperometric electrode and nitrate assay of fertilizers and drinking water SO ANALYTICAL CHEMISTRY LA English DT Article ID NITRITE; NAFION AB The construction and characterization of a nitrate reductase-based amperometric electrode for determination of nitrate ion is described. The electrode consisted of nitrate reductase held by dialysis membrane onto a Nation-coated glassy carbon electrode. Methyl viologen was allowed to absorb into the Nation layer, which acted as a reservoir for the electron mediator. The utility of the electrode to assay fertilizer and water sample for nitrate was demonstrated. The assays conducted with this electrode compared well with colorimetric and potentiometric assays of the same samples. C1 Natl Inst Stand & Technol, Div Biotechnol, Biomol Mat Grp, Gaithersburg, MD 20899 USA. Nitrate Eliminat Co Inc, Lake Linden, MI 49945 USA. RP Glazier, SA (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Biomol Mat Grp, Gaithersburg, MD 20899 USA. NR 19 TC 63 Z9 67 U1 1 U2 10 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 1998 VL 70 IS 8 BP 1511 EP 1515 DI 10.1021/ac971146s PG 5 WC Chemistry, Analytical SC Chemistry GA ZH511 UT WOS:000073118400008 PM 9569760 ER PT J AU Storebakken, T Shearer, KD Refstie, S Lagocki, S McCool, J AF Storebakken, T Shearer, KD Refstie, S Lagocki, S McCool, J TI Interactions between salinity, dietary carbohydrate source and carbohydrate concentration on the digestibility of macronutrients and energy in rainbow trout (Oncorhynchus mykiss) SO AQUACULTURE LA English DT Article DE diet carbohydrate glucose dextrin; digestibility-macronutrients-energy interaction; salinity; rainbow trout Oncorhynchus mykiss ID GUAR GUM; GASTROINTESTINAL-TRACT; SALMO-GAIRDNERI; GROWTH; DIGESTION; CHOLESTEROL; ABSORPTION; SEAWATER; PROTEIN; STARCH AB The aim of the experiment was to determine if salinity, dietary carbohydrate source, and dietary carbohydrate concentration affected the digestibility of macronutrients and energy in rainbow trout, and also to determine if there were interactions between these factors. The trout, reared in freshwater or saltwater, were fed four diets, containing moderate (100 g kg(-1)) or high (200 g kg(-1)) concentrations of glucose or maize dextrin as partial replacements for fish meal. Faecal samples were obtained by stripping and apparent digestibility coefficients (ADC) of macronutrients and energy were estimated using the indirect method with yttrium oxide, Y2O3, as an inert marker. The ADCs of organic material, fat, carbohydrate and energy were significantly higher in freshwater than in saltwater. The ADCs of organic material, carbohydrate and energy were higher for the diets with glucose than for dextrin. The diets with 100 g carbohydrate kg(-1) resulted in higher ADCs of protein and fat than diets with 200 g kg(-1). The opposite was found for the ADC of carbohydrate. This is ascribed to the fish meal used in the diets being contaminated with starch. The ADCs of fat, organic material and energy were negatively related to the concentration of indigestible carbohydrate from dextrin and starch in the diets, while that of protein was not. Significant interactions were seen between salinity and dietary carbohydrate source for the ADC of protein, and between carbohydrate source and concentration for ADCs of organic material, fat and energy. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Inst Aquaculture Res, AKVAFORSK, N-6600 Sunndalsora, Norway. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. Univ Plymouth, Dept Biol Sci, Plymouth PL4 8AA, Devon, England. Wolverhampton Univ, Inst Biochem, Wolverhampton WV1 1DJ, W Midlands, England. RP Storebakken, T (reprint author), Inst Aquaculture Res, AKVAFORSK, N-6600 Sunndalsora, Norway. RI storebakken, trond/E-8050-2011 OI storebakken, trond/0000-0002-4525-2098 NR 33 TC 53 Z9 54 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD APR 15 PY 1998 VL 163 IS 3-4 BP 347 EP 359 DI 10.1016/S0044-8486(98)00259-2 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA ZX350 UT WOS:000074506700013 ER PT J AU Paik, U Hackley, VA Choi, SC Jung, YG AF Paik, U Hackley, VA Choi, SC Jung, YG TI The effect of electrostatic repulsive forces on the stability of BaTiO3 particles suspended in non-aqueous media SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE dispersion; barium titanate; phosphate ester; menhaden fish oil; adsorption; viscosity; electrostatic stabilization; steric stabilization ID NONAQUEOUS MEDIA; SILICA POWDERS; ALUMINA; DISPERSIONS; ADSORPTION; CERAMICS AB The effects of physicochemical properties of organic solvents and dispersants on the dispersion of barium titanate (BaTiO3) was investigated in a system where organic solvents, dispersants, binders, and plasticizers are used as processing additives in multilayer ceramic capacitor fabrication processes. In this study, phosphate esters and menhaden fish oil were used as dispersants. The dispersion properties of BaTiO3 suspensions were characterized by electrokinetic sonic amplitude, polymer adsorption and viscosity measurements. The steric and electrostatic stabilization mechanisms affecting the suspension properties of BaTiO3 were evaluated. The adsorption characteristics and electrokinetic behavior of BaTiO3 suspensions were correlated with the stability of BaTiO3 suspended in non-aqueous media. The stability of BaTiO3 achieved by steric stabilization was dependent on the fraction of surface coverage resulting from dispersant adsorption on the BaTiO3 particle. The electrostatic repulsive forces acting between BaTiO3 particles dispersed in organic media was found to be significantly greater than predicted and dependent mainly on the physicochemical properties of the organic solvent media. (C) 1998 Elsevier Science B.V. C1 Changwon Natl Univ, Dept Mat Sci & Engn, Changwon 641773, Kyungnnam, South Korea. NIST, Div Ceram, Gaithersburg, MD 20899 USA. Hanyang Univ, Dept Inorgan Mat Engn, Seoul 133791, South Korea. RP Paik, U (reprint author), Changwon Natl Univ, Dept Mat Sci & Engn, Changwon 641773, Kyungnnam, South Korea. NR 25 TC 64 Z9 64 U1 3 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD APR 15 PY 1998 VL 135 IS 1-3 BP 77 EP 88 DI 10.1016/S0927-7757(97)00234-3 PG 12 WC Chemistry, Physical SC Chemistry GA ZK424 UT WOS:000073319500009 ER PT J AU Irwin, KD Hilton, GC Wollman, DA Martinis, JM AF Irwin, KD Hilton, GC Wollman, DA Martinis, JM TI Thermal-response time of superconducting transition-edge microcalorimeters SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTROTHERMAL FEEDBACK; PARTICLE-DETECTION; ALUMINUM; SENSOR; FILMS; NOISE AB We investigate limits on the thermal-response time of superconducting transition-edge microcalorimeters. For operation at 0.1 K, we show that the lower limit on the response time of a superconducting transition-edge microcalorimeter is of order 1 mu s due to the heat diffusion time, electrical instabilities, the amplifier noise, and the critical current of the superconducting film. The response time is not limited by self-heating effects and is independent of the intended photon energy. However, design constraints associated with the inductance of the bias circuit make it difficult to achieve the fastest response times for devices with heat capacities high enough for x-ray and gamma-ray detection. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Irwin, KD (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 20 TC 139 Z9 139 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 3978 EP 3985 DI 10.1063/1.367153 PG 8 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900004 ER PT J AU Bullard, JW Garboczi, EJ Carter, WC AF Bullard, JW Garboczi, EJ Carter, WC TI Interplay of capillary and elastic driving forces during microstructural evolution: Applications of a digital image model SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID COHERENT TETRAGONAL PRECIPITATE; SOLID PHASE-TRANSITIONS; STABILIZED CUBIC ZRO2; COMPUTER-SIMULATION; STRESSED SOLIDS; COMPOSITES; INTERFACES; DYNAMICS; SHAPE AB A recently developed model of curvature-driven, two-dimensional microstructure evolution is modified to include elastic strain energy at solid-fluid interfaces as an additional driving force for mass transport. Local phase distributions within a digital image of the microstructure are used to interpolate an isopotential contour that represents the equivalent sharp surface, along which local properties such as curvature are calculated. To determine the strain energy distribution, a finite element method is employed, using the pixel grid as the mesh. Interface-reaction-controlled mass transport is simulated using a finite difference approach along the interface. Calculations of the strain energy density and chemical potential distributions within simple systems show reasonable agreement with analytical results, and the predicted stability and evolution of such systems also agree with the predictions of other investigators. The model is also applied to a more complex system for which neither analytical nor other numerical methods can be readily used, and useful quantitative information is obtained on the energetics and structural changes. (C) 1998 American Institute of Physics. C1 Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. Natl Inst Stand & Technol, Bldg Mat Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Bullard, JW (reprint author), Univ Illinois, Dept Mat Sci & Engn, 1304 W Green St, Urbana, IL 61801 USA. RI Carter, W/K-2406-2012 NR 28 TC 8 Z9 8 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4477 EP 4486 DI 10.1063/1.367210 PG 10 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900076 ER PT J AU Moore, WS Kjerfve, B Todd, JF AF Moore, WS Kjerfve, B Todd, JF TI Identification of rain-freshened plumes in the coastal ocean using Ra isotopes and Si SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SOUTHEASTERN UNITED-STATES; CONTINENTAL-SHELF; FRONTAL ZONE; WATERS; RA-228 AB Two transient plumes of freshened water in the South Atlantic Eight off the coast of South Carolina were measured and mapped during a continental shelf cruise in July 1994. Salinity in the plumes was depressed 1-2 parts per thousand compared to surrounding shelf waters. One plume was at least 160 km long, 20 km wide, and 5-7 m deep. The other was 75 km long, 25 km wide and 5-7 m deep. Both plumes disintegrated almost completely in 6 days due to mixing or advection away from the sampling area. Measurement and analysis of short-lived Ra isotopes and Si indicated that the plumes were not caused by river discharge but were rather due to an intense rain event a few days prior to the sampling cruise. With only salinity measurements we would have incorrectly concluded that the freshened water was a result of river plumes having entered the shelf. The rain was associated with the system that spawned tropical storm Alberto. We estimate that 220-330 mm of rain fell on the coastal ocean immediately before the cruise. Accompanying the rain were pesticides and nutrients. We estimate that the flux of nitrate from the rain was twice the riverine flux of nitrate to the study area in the month preceding the cruise. C1 Univ S Carolina, Dept Geol Sci, Columbia, SC 29208 USA. Univ S Carolina, Marine Sci Program, Columbia, SC 29208 USA. NOAA, Off Global Programs, Silver Spring, MD 20910 USA. RP Moore, WS (reprint author), Univ S Carolina, Dept Geol Sci, Columbia, SC 29208 USA. RI Moore, Willard/B-6096-2016 OI Moore, Willard/0000-0001-5930-5325 NR 23 TC 16 Z9 16 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1998 VL 103 IS C4 BP 7709 EP 7717 DI 10.1029/98JC00246 PG 9 WC Oceanography SC Oceanography GA ZH476 UT WOS:000073114800018 ER PT J AU Arnone, RA Ladner, S La Violette, PE Brock, JC Rochford, PA AF Arnone, RA Ladner, S La Violette, PE Brock, JC Rochford, PA TI Seasonal and interannual variability of surface photosynthetically available radiation in the Arabian Sea SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NORTH-ATLANTIC; SOUTHWEST MONSOON; SOLAR IRRADIANCE; PACIFIC-OCEAN; PHYTOPLANKTON; PARTICLES; MODEL AB The regional and monthly intensity of photosynthetically available radiation (PAR) (350-700 nm) just below the sea surface (Ed(PAR)(-)) for the Arabian Sea is determined from solar irradiance models and 7 years of satellite data (1979-1985), Model results of high spatial resolution (18 km) PAK distribution computed from actual monthly measurements (aerosols, cloud cover, and ozone) displayed small-scale patchiness that is not observed in PAR climatology models. Two elevated PAR periods are observed each year, as opposed to a single elevated period per year observed in the North Atlantic during the summer. When the biannual cycle for each of the 7 years is compared with the 7-year average, interannual changes in intensity and time are observed. Additionally, the PAR cycle is found to vary regionally within the Arabian Sea, The bimodal PAR distribution shows elevated peaks in May and October and minima in December (corresponding to the winter equinox) and July. The second minima occurs at the onset of the southwest monsoon, apparently in response to increased cloud cover and aerosols associated with the monsoon. This summer minima varied latitudinally. It originates in the southern regions (0 degrees-10 degrees latitude) in April and migrates north as the influence of the southwest monsoon moves northward, reaching the northern Oman coast (20 degrees latitude) in August. Additionally, the summer minima is Less pronounced as the southwest monsoon moves northward. Maximum PAR intensity is observed in early spring (preceding the minima), originating in the southern Arabian Sea and extending northward into the central Arabian Sea. The timing of the northward movement of this spring maximum is slightly different each year. The net yearly PAR intensity for each of the 7 years appears to remain approximately the same, despite the interannual variability in the cycle and regional variability. The timing and location of PAR cycles are important since they must be coupled with nutrient availability to understand biological cycles. We determined that for the Arabian Sea, PAR cycles determined by climatology may be inadequate to define the submarine light field and that high-resolution PAR cycles are needed to resolve realistic bio-optical and nutrient cycles. C1 USN, Res Lab, Stennis Space Ctr, MS 39529 USA. NOAA, Coastal Serv Ctr, Charleston, SC 29405 USA. Gulf Weather Corp, Stennis Space Ctr, MS 39529 USA. Severdrup Technol Inc, Stennis Space Ctr, MS 39529 USA. Planning Sci Inc, Slidell, LA 70458 USA. RP Arnone, RA (reprint author), USN, Res Lab, Code 7343, Stennis Space Ctr, MS 39529 USA. EM arnone@nrlssc.navy.mil NR 38 TC 11 Z9 11 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1998 VL 103 IS C4 BP 7735 EP 7748 DI 10.1029/97JC03204 PG 14 WC Oceanography SC Oceanography GA ZH476 UT WOS:000073114800020 ER PT J AU Holt, B Liu, AK Wang, DW Gnanadesikan, A Chen, HS AF Holt, B Liu, AK Wang, DW Gnanadesikan, A Chen, HS TI Tracking storm-generated waves in the northeast Pacific Ocean with ERS-1 synthetic aperture radar imagery and buoys SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SPECTRA; SAR; INVERSION; ALGORITHM; TRANSFORM AB This paper examines the capability of synthetic aperture radar imagery from ERS-1 and buoys to track the wave field emanating from an intense storm over a several-day period. The first part of the study is a validation component that compares SAR-derived wave length and direction with buoy data from two locations over 10 different dates in late 1991 and National Oceanic and Atmospheric Administration (NOAA) wave model (WAM) wave direction results. When the SAR is linear (8 out of 10 cases), mean wavelength is within 5% of the buoy measurements and mean wave direction is within 1 degrees of direction derived from the wave model (albeit with a large standard deviation of 27 degrees), indicating close agreement. The wave field generated from the intense storm in late December 1991 was measured by three separate ERS-1 SAR passes over a 3-day period. A simple kinematic model was used for waves propagating from a storm. Comparing the model results with both SAR and buoy data indicates that SAR-derived peak wavelength and direction measurements can be reliably used to predict arrival times and propagation direction over a several-day period and considerable distances. The measurements can also be used to derive estimated wave generation source regions about the storm as well. Such measurements are useful for comparing with wave model results, which perform less accurately for direction than wave height for example, and for predicting hazardous conditions for ship navigation and coastal regions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NOAA, Natl Ctr Environm Predict, Washington, DC 20233 USA. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08540 USA. NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. Comp Sci Corp, Appl Technol Div, Stennis Space Ctr, MS 39529 USA. RP Holt, B (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ben@pacific.jpl.nasa.gov RI Gnanadesikan, Anand/A-2397-2008 OI Gnanadesikan, Anand/0000-0001-5784-1116 NR 43 TC 14 Z9 16 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD APR 15 PY 1998 VL 103 IS C4 BP 7917 EP 7929 DI 10.1029/97JC02567 PG 13 WC Oceanography SC Oceanography GA ZH476 UT WOS:000073114800034 ER PT J AU Nance, LB Durran, DR AF Nance, LB Durran, DR TI A modeling study of nonstationary trapped mountain lee waves. Part II: Nonlinearity SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID UPPER BOUNDARY-CONDITION AB The generation of nonstationary trapped mountain lee waves through nonlinear wave dynamics without any concomitant change in the background flow is investigated by conducting two-dimensional mountain wave simulations. These simulations demonstrate that finite-amplitude lee-wave patterns can exhibit temporal variations in local wavelength and amplitude, even when the background flow is perfectly steady. For moderate amplitudes, a nonlinear a ave interaction involving the stationary trapped wave and a pair of nonstationary waves appears to be responsible for the development of nonstationary perturbations on the stationary trapped wave. This pair of nonstationary waves consists of a trapped wave and a pair of nonstationary wave, both having horizontal wavelengths approximately twice that of the stationary trapped wave. As the flow becomes more nonlinear, the nonstationary perturbations involve a wider spectrum of horizontal wavelengths and may dominate the overall wave pattern at wave amplitudes significantly below the threshold required to produce wave breaking. Sensitivity tests in which the wave propagation characteristics of the basic state are modified without changing the horizontal wavelength of the stationary trapped wave indicate these nonstationary perturbations are absent when the background flow does nor support nonstationary trapped waves with horizontal wavelengths approximately twice that of the stationary trapped mode. These sensitivity tests also show that a second nonstationary trapped wave can assume the role of the nonstationary vertically propagating wave when the Scorer parameter in the upper layer is reduced below the threshold that will support the vertically propagating wave. In this case, a resonant triad composed of three trapped waves appears to be responsible for the development of nonstationary perturbations. The simulations suggest that strongly nonlinear wave dynamics can generate a wider range of nonstationary trapped modes than that produced by temporal variations in the background flow. It is suggested that the irregular variations in lee-wave wavelength and amplitude observed in real atmospheric flows and the complex fluctuations above a fixed point that are occasionally found in wind profiler observations of trapped lee waves are more likely to be generated by nonlinear wave dynamics than changes in the background flow. C1 Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. RP Nance, LB (reprint author), NOAA, Natl Weather Serv, 7600 Sand Point Way NE,Bin C15700, Seattle, WA 98115 USA. RI Durran, Dale/G-3677-2015 OI Durran, Dale/0000-0002-6390-2584 NR 28 TC 36 Z9 37 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD APR 15 PY 1998 VL 55 IS 8 BP 1429 EP 1445 DI 10.1175/1520-0469(1998)055<1429:AMSONT>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZJ701 UT WOS:000073244000009 ER PT J AU Benedict, LX Shirley, EL Bohn, RB AF Benedict, LX Shirley, EL Bohn, RB TI Theory of optical absorption in diamond, Si, Ge, and GaAs SO PHYSICAL REVIEW B LA English DT Article ID QUASIPARTICLE ENERGIES; SEMICONDUCTORS; INSULATORS; SPECTRUM AB We report first-principles calculations of epsilon(2)(omega) for diamond, Si, Ge, and GaAs that include the electron-hole interaction in detail. The only essential experimental input is the crystal structure of the materials. Comparison with reflectivity and ellipsometry measurements allows us to assess the validity of the approximations made in the calculation. We conclude that the approximation of singly excited electronic states and a statically screened electron-hole interaction is sufficient to understand the main features of the absorption spectra of these materials in the visible to near ultraviolet. [S0163-1829(98)51416-6]. C1 Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Informat Technol Lab, High Performance Syst & Serv Div, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 19 TC 105 Z9 105 U1 4 U2 8 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1998 VL 57 IS 16 BP R9385 EP R9387 DI 10.1103/PhysRevB.57.R9385 PG 3 WC Physics, Condensed Matter SC Physics GA ZJ381 UT WOS:000073209000004 ER PT J AU Cheong, HM Mascarenhas, A Geisz, JF Olson, JM Keller, MW Wendt, JR AF Cheong, HM Mascarenhas, A Geisz, JF Olson, JM Keller, MW Wendt, JR TI Statistical distribution of the order parameter in spontaneously ordered Ga0.52In0.48P alloys SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM DOTS; PHOTOLUMINESCENCE; GAINP2; SPECTROSCOPY; SPECTRA AB The spontaneously ordered Ga0.52In0.48P alloy comprises domains, each of which is characterized by an order parameter eta. We have used the low-temperature near-field photoluminescence technique with a high spatial resolution (less than or equal to 2500 Angstrom) to study the statistical distribution of the order parameter eta of single-variant ordered alloys. We have found that for large-domain samples, eta varies only slightly between domains and the line width broadening of the excitonic photoluminescence peak comes mainly from alloy scattering within a single domain rather than from a broad distribution of eta. [S0163-1829(98)52416-2]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cheong, HM (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Cheong, Hyeonsik/D-7424-2012 OI Cheong, Hyeonsik/0000-0002-2347-4044 NR 17 TC 17 Z9 17 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 APR 15 PY 1998 VL 57 IS 16 BP R9400 EP R9403 DI 10.1103/PhysRevB.57.R9400 PG 4 WC Physics, Condensed Matter SC Physics GA ZJ381 UT WOS:000073209000008 ER PT J AU Gallagher, DT Gilliland, GL Xiao, GY Zondlo, J Fisher, KE Chinchilla, D Eisenstein, E AF Gallagher, DT Gilliland, GL Xiao, GY Zondlo, J Fisher, KE Chinchilla, D Eisenstein, E TI Structure and control of pyridoxal phosphate dependent allosteric threonine deaminase SO STRUCTURE WITH FOLDING & DESIGN LA English DT Article DE allostery; cooperativity; crystal structure; pyridoxal phosphate; threonine deaminase ID AMINO-ACID SEQUENCE; ESCHERICHIA-COLI; TRYPTOPHAN SYNTHASE; CORYNEBACTERIUM-GLUTAMICUM; ASPARTATE-AMINOTRANSFERASE; MACROMOLECULAR STRUCTURES; 3-DIMENSIONAL STRUCTURE; SPATIAL STRUCTURE; LIGAND-BINDING; ENZYMES AB Background: Feedback inhibition of biosynthetic threonine deaminase (TD) from Escherichia coli provided one of the earliest examples of protein-based metabolic regulation. Isoleucine, the pathway end-product, and valine, the product of a parallel pathway, serve as allosteric inhibitor and activator, respectively. This enzyme is thus a useful model system for studying the structural basis of allosteric control mechanisms. Results: We report the crystal structure of TD at 2.8 Angstrom resolution, The tetramer has 222 symmetry, with C-terminal regulatory domains projecting out from a core of catalytic PLP-containing N-terminal domains. The subunits, and especially the regulatory domains, associate extensively to form dimers, which associate less extensively to form the tetramer. Within the dimer, each monomer twists approximately 150 degrees around a thin neck between the domains to place its catalytic domain adjacent to the regulatory domain df the other subunit, Conclusions: The structure of TD and its comparison with related structures and other data lead to the tentative identification of the regulatory binding site and revealed several implications for the allosteric mechanism, This work prepares the way for detailed structure/function studies of the complex allosteric behaviour of this enzyme. C1 Univ Maryland, Inst Biotechnol, Ctr Adv Res Biotechnol, Natl Inst Stand & Technol, Rockville, MD 20850 USA. Univ Maryland Baltimore Cty, Dept Chem & Biochem, Baltimore, MD 21228 USA. RP Gallagher, DT (reprint author), Univ Maryland, Inst Biotechnol, Ctr Adv Res Biotechnol, Natl Inst Stand & Technol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. EM travis@dtg.nist.gov NR 57 TC 134 Z9 138 U1 1 U2 15 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON W1P 6LB, ENGLAND SN 0969-2126 J9 STRUCT FOLD DES JI Struct. Fold. Des. PD APR 15 PY 1998 VL 6 IS 4 BP 465 EP 475 DI 10.1016/S0969-2126(98)00048-3 PG 11 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA ZM167 UT WOS:000073511400007 PM 9562556 ER PT J AU Cypser, DA Davis, SD AF Cypser, DA Davis, SD TI Induced seismicity and the potential for liability under US law SO TECTONOPHYSICS LA English DT Article; Proceedings Paper CT IASPEI Symposium on New Trends in Seismological Research - Studies of Seismicity Induced by Mining, Petroleum and Geothermal Activities at the IUGG Meeting CY JUL, 1995 CL BOULDER, COLORADO SP IASPEI, Gen Assembly Int Union Geodesy & Geophys DE triggered induced seismicity; earthquakes; liability; legal ID RESERVOIR-INDUCED SEISMICITY; TRIGGERED EARTHQUAKES; CALIFORNIA; FIELD; TEXAS; STATE AB Research by seismologists over the past 30+ years has firmly established that some human activities induce seismicity. Sometimes induced seismicity causes injuries to people or property. The activities which induce seismicity generally involve extraction of energy, or natural resources, or the disposal of wastes. As the human population increases these extraction and disposal activities will increase in number of sites and intensity of effort as the demands became greater and the resources scarcer. With these increases the number and severity of damaging induced earthquakes is likely to increase. Induced seismicity may cause injuries by vibrations or by seismically induced ground failure. In either case compensation for injuries caused by induced seismicity should be paid for by the inducer. In the United States the inducer of damaging seismicity can be made to pay for the harm caused. Liability for damage caused by vibrations can be based on several legal theories: trespass, strict liability, negligence and nuisance. Our research revealed no cases in which an appellate court has upheld or rejected the application of tort liability to an induced earthquake situation. However, there are numerous analogous cases that support the application of these legal theories to induced seismicity. Vibrations or concussions due to blasting or heavy machinery are sometimes viewed as a 'trespass' analogous to a physical invasion. In some states activities which induce earthquakes might be considered 'abnormally dangerous' activities that require companies engaged in them to pay for injuries the quakes cause regardless of how careful the inducers were. In some circumstances, a court may find that an inducer was negligent in its site selection or in maintenance of the project. If induced seismicity interferes with the use or enjoyment of another's land, then the inducing activity may be a legal nuisance, even if the seismicity causes little physical damage. In most states of the United States owners of land owe a duty of lateral support to adjacent landowners, and, in some states, mineral estate owners and lessees owe a duty of subjacent support to the surface owners. Failure to meet those duties of support can result in liability. Seismicity induced by one source might accelerate failure of support originating from another source, leaving both of the parties at fault proportionally liable to the injured parties. Geoscientists can use their roles as investigators, educators and advisors to help companies in the petroleum, mining and geothermal fields avoid liability. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Geophys Data Ctr, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. RP Cypser, DA (reprint author), POB 2187, Boulder, CO 80306 USA. EM dcypser@nyx.net NR 75 TC 7 Z9 7 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD APR 15 PY 1998 VL 289 IS 1-3 BP 239 EP 255 DI 10.1016/S0040-1951(97)00318-1 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZR956 UT WOS:000074033200017 ER PT J AU Wang, YL Hsu, SM AF Wang, YL Hsu, SM TI Lubricated friction and wear simulation of multi-scratches in asperity-asperity contact SO WEAR LA English DT Article DE asperity; contact; lubrication; wear; collision; scratch ID SURFACE AB Multi-scratch tests of ball-on-ball (3.175 mm diameter 52100 steel) in lubrication were carried out to simulate the friction and wear process of the asperity-asperity contact in sliding. The results show that the friction coefficient increases with the increased scratch number from about 0.1 at the 1st scratch to about 0.4 at the 40th scratch. There is no plastic deformation and wear on the contact surface for the Ist scratch. However, friction coefficient rises to 0.15 at the 5th scratch and abrasive wear occurs in the contact area. Then, with the scratch number increased further, the friction coefficient continues to increase and the contact surface undergoes different wear stages: plastic smearing (10th scratch), surface flaw initiation (20th scratch), and tensile crack initiation and propagation (40th scratch). (C) 1998 Elsevier Science S.A. All rights reserved. C1 Iomega, Milpitas, CA 95035 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Wang, YL (reprint author), Iomega, 800 Tasman Dr, Milpitas, CA 95035 USA. NR 13 TC 9 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR 15 PY 1998 VL 217 IS 1 BP 104 EP 109 DI 10.1016/S0043-1648(98)00149-5 PG 6 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA ZV096 UT WOS:000074268500012 ER PT J AU Vander Rhodes, GH Pomeroy, JM Unlu, MS Goldberg, BB Knopp, KJ Christensen, DH AF Vander Rhodes, GH Pomeroy, JM Unlu, MS Goldberg, BB Knopp, KJ Christensen, DH TI Pump intensity profiling of vertical-cavity surface-emitting lasers using near-field scanning optical microscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID SEMICONDUCTOR AB We have mapped the internal pump intensity distribution of an optically pumped vertical-cavity surface-emitting laser. Spontaneous emission from quantum wells placed throughout the distributed Bragg reflectors is correlated to the pump intensity. The emission is monitored along the cleaved edge using the high spatial resolution and shallow depth of field provided by near-field scanning optical microscopy. Our results show a distinct buildup of optical intensity between the mirror stacks, Simulations performed using the transfer matrix method march well with the: experimental data. (C) 1998 American Institute of Physics. C1 Boston Univ, Photon Ctr, Dept Phys, Boston, MA 02215 USA. Boston Univ, Photon Ctr, Dept Elect & Comp Engn, Boston, MA 02215 USA. Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. RP Vander Rhodes, GH (reprint author), Boston Univ, Photon Ctr, Dept Phys, Boston, MA 02215 USA. EM gregvr@bu.edu RI Unlu, Selim/B-4244-2013 NR 9 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 13 PY 1998 VL 72 IS 15 BP 1811 EP 1813 DI 10.1063/1.121192 PG 3 WC Physics, Applied SC Physics GA ZG930 UT WOS:000073054300005 ER PT J AU Mitchell, TB Bollinger, JJ Huang, XP Itano, WM AF Mitchell, TB Bollinger, JJ Huang, XP Itano, WM TI Doppler imaging of plasma modes in a Penning trap SO OPTICS EXPRESS LA English DT Article ID ION-PLASMA; ELECTROSTATIC MODES; THERMAL-EQUILIBRIUM; NONNEUTRAL PLASMA; COMPONENT PLASMAS; ORDER; ANTIPROTONS; CRYSTALS AB We describe a technique and present results for imaging the modes of a laser-cooled plasma of Be-9(+) ions in a Penning trap. The modes are excited by sinusoidally time-varying potentials applied to the trap electrodes. They are imaged by changes in the ion resonance fluorescence produced by Doppler shifts from the coherent ion velocities of the mode. For the geometry and conditions of this experiment, the mode frequencies and eigenfunctions have been calculated analytically. A comparison between theory and experiment for some of the azimuthally symmetric modes shows good agreement. (C)1998 Optical Society of America C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Mitchell, TB (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. NR 21 TC 21 Z9 21 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD APR 13 PY 1998 VL 2 IS 8 BP 314 EP 322 PG 9 WC Optics SC Optics GA 122PA UT WOS:000076079600003 PM 19381196 ER PT J AU Coakley, KJ AF Coakley, KJ TI Statistical planning for a neutron lifetime experiment using magnetically trapped neutrons SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID LIKELIHOOD; DECAY AB At the NIST Cold Neutron Research Facility, a two-stage experiment will be repeated many times. During the first stage of each run cycle, ultracold neutrons will be produced and confined in a magnetic trap filled with superfluid He-4. Ultracold neutrons will result when cold (8.9 Angstrom) neutrons undergo inelastic scattering in the superfluid helium. After filling the trap to a desired level, decay events will be recorded as a function of time. Detection is possible because the charged particles created by neutron decay generate detectable scintillations in the helium. In addition to neutron decay events, background events will be recorded. I model the background as a stationary Poisson process. By Monte Carlo methods, I study the performance of two nonlinear algorithms for estimating the mean lifetime of the neutron. In one method, the event time data are summarized as a histogram where the bin widths vary. I select the time endpoints of the bins so that the expected number of counts per bin contributed by the decay process is approximately constant. In the second method, the lifetime is estimated from the complete sequence of event times. The histogram method yields a less variable estimate than does the complete data estimation method. The allocation of time between the fill and decay stages affects the precision of the estimate. To get the optimal time allocation, I minimize the asymptotic variance of the estimated mean lifetime (estimated from the pooled histogram data from all cycles) given knowledge of the rate at which neutrons enter the trap and parameters which characterize the background. The mean lifetime estimate is biased. I observe bias reduction when estimating the lifetime from data pooled from many cycles (rather than averaging estimates from each of the cycles). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Stat Engn Div, Boulder, CO 80303 USA. RP Coakley, KJ (reprint author), Natl Inst Stand & Technol, Stat Engn Div, Mail Stop 898-02,325 Broadway, Boulder, CO 80303 USA. NR 14 TC 6 Z9 6 U1 0 U2 1 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 11 PY 1998 VL 406 IS 3 BP 451 EP 463 DI 10.1016/S0168-9002(97)00013-2 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZP135 UT WOS:000073719900011 ER PT J AU Wong-Ng, W Cook, LP Greenwood, W AF Wong-Ng, W Cook, LP Greenwood, W TI Melting of Sr14Cu24O41 at oxygen pressures of 0.0075, 0.021 and 0.1 MPa SO PHYSICA C LA English DT Article DE Sr14Cu24O41 melting; oxygen pressure; 0.0075 MPa; 0.021 Mpa; 0.1 Mpa ID PHASE-EQUILIBRIA; SYSTEM; STABILITY; CUO AB The eutectic and peritectic melting equilibria of the Sr14Cu24O41 phase have been studied at oxygen pressures of 0.0075, 0.021, and 0.1 MPa. The Sr14Cu24O41 primary phase field was determined using a combination of differential thermal analysis and electron beam microanalysis of quenched liquids. It was found that the incongruent melting of Sr14Cu24O41 takes place at 925, 975, and 1032 degrees C at P-O2=0.0075, 0.021, and 0.1 MPa, respectively. The peritectic melting reaction under all conditions was confirmed to be: Sr14Cu24O41-->SrCuO2+Liquid+O-2. The liquid composition of this melt was found to range from 79.8% (mole fraction, at P-O2=0.0075 MPa) to 83.9% CuO (mole fraction, at P-O2=0.1 MPa). The copper oxidation state in these liquids, as estimated from thermogravimetric data, ranged from Cu+1.42 (at P-O2=0.0075 MPa) to Cu+1.46 (at P-O2=0.1 MPa). The eutectic melting in the SrO-CuO system occurs at 918 degrees C (mole fraction of 81.7% CuO), 965 degrees C (mole fraction of 85.0% CuO), and 1005 degrees C (mole fraction of 86.7% CuO) at P-O2=0.0075, 0.021, and 0.1 MPa, respectively. The temperature range of the Sr14Cu24O41 primary crystallization field was found to increase from 7 degrees C at P-O2=0.0075 MPa to 28 degrees C at P-O2=0.1 MPa, but the compositional width remains small (<4%) at all three oxygen pressures. These data provide important points on the Sr-Cu-O phase diagram. The data are discussed with reference to the growth of Sr14Cu24O41 crystals. (C) 1998 Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Geol, College Pk, MD 20742 USA. RP Wong-Ng, W (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. NR 18 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD APR 10 PY 1998 VL 299 IS 1-2 BP 9 EP 14 DI 10.1016/S0921-4534(98)00045-8 PG 6 WC Physics, Applied SC Physics GA ZM022 UT WOS:000073496900002 ER PT J AU Sanov, A Lineberger, WC Jordan, KD AF Sanov, A Lineberger, WC Jordan, KD TI Electronic structure of (CS(2))(2)(-) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Letter ID CLUSTERS AB We investigate theoretically the electronic structure of (CS(2))(2)(-). Five different low-lying forms of the anion are identified. These include the ion-molecule complex and a covalently bonded dimer anion, both of which have electronic configurations consistent with electron attachment to the LUMO of the van der Waals dimer. The other species, including the most stable form of the anion, all have cyclic structures and can be viewed as arising from electron capture by cyclic covalently bonded neutral dimers, with electronic configurations doubly excited with respect to the van der Waals dimer. Vertical detachment energies are calculated for the various anions and lead us to reassign the features in the observed photoelectron spectra of (CS(2))(2)(-). C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Pittsburgh, Dept Chem, Pittsburgh, PA 15260 USA. RP Sanov, A (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 17 TC 34 Z9 34 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD APR 9 PY 1998 VL 102 IS 15 BP 2509 EP 2511 DI 10.1021/jp9809639 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZJ962 UT WOS:000073271200003 ER PT J AU Richardson, LL Goldberg, WM Kuta, KG Aronson, RB Smith, GW Ritchie, KB Halas, JC Feingold, JS Miller, SL AF Richardson, LL Goldberg, WM Kuta, KG Aronson, RB Smith, GW Ritchie, KB Halas, JC Feingold, JS Miller, SL TI Florida's mystery coral-killer identified SO NATURE LA English DT Letter ID BLACK C1 Florida Int Univ, Dept Biol Sci, Miami, FL 33199 USA. Dauphin Isl Sea Lab, Dauphin Island, AL 36528 USA. Univ S Carolina, Dept Biol, Aiken, SC 29801 USA. Florida Keys Natl Marine Sanctuary, Key Largo, FL 33037 USA. Nova SE Univ, Oceanog Ctr, Dania, FL 33004 USA. Univ N Carolina, Natl Undersea Res Ctr, Wilmington, NC 28403 USA. RP Richardson, LL (reprint author), Florida Int Univ, Dept Biol Sci, Miami, FL 33199 USA. NR 10 TC 163 Z9 168 U1 4 U2 25 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 9 PY 1998 VL 392 IS 6676 BP 557 EP 558 DI 10.1038/33302 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZG300 UT WOS:000072987200036 ER PT J AU Copie, V Tomita, Y Akiyama, SK Aota, S Yamada, KM Venable, RM Pastor, RW Krueger, S Torchia, DA AF Copie, V Tomita, Y Akiyama, SK Aota, S Yamada, KM Venable, RM Pastor, RW Krueger, S Torchia, DA TI Solution structure and dynamics of linked cell attachment modules of mouse fibronectin containing the RGD and synergy regions: Comparison with the human fibronectin crystal structure SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE fibronectin; cell adhesion; RGD region; NMR; protein flexibility ID ISOTOPICALLY ENRICHED PROTEINS; SIDE-CHAIN RESONANCES; N-15 NMR RELAXATION; CARBON-J-COUPLINGS; 3-DIMENSIONAL STRUCTURE; C-13-ENRICHED PROTEINS; ROTATIONAL DIFFUSION; C-13 MAGNETIZATION; ADHESIVE FUNCTION; LARGER PROTEINS AB We report the three-dimensional solution structure of the mouse fibronectin cell attachment domain consisting of the linked ninth and tenth type III modules, mFnFn3(9,10). Because the tenth module contains the RGD cell attachment sequence while the ninth contains the synergy region, mFnFn3(9,10) has the cell attachment activity of intact fibronectin. Essentially complete signal assignments and approximately 1800 distance and angle restraints were derived from multidimensional heteronuclear NMR spectra. These restraints were used with a hybrid distance geometry/simulated annealing protocol to generate an ensemble of 20 NMR structures having no distance or angle violations greater than 0.3 Angstrom or 3 degrees. Although the beta-sheet core domains of the individual modules are well-ordered structures, having backbone atom rmsd values from the mean structure of 0.51(+/-0.12) and 0.40(+/-0.07) Angstrom, respectively, the rmsd of the core atom coordinates increases to 3.63(+/-1.41) A when the core domains of both modules are used to align the coordinates. The latter result is a consequence of the fact that the relative orientation of the two modules is not highly constrained by the NMR restraints. Hence, while structures of the beta-sheet core domains of the NMR structures are very similar to the core domains of the crystal structure of hFnFn3(9,10), the ensemble of NMR structures suggests that the two modules form a less extended and more flexible structure than the fully extended rod-like crystal structure. The radius of gyration, R-g, of mFnFn3(9,10) derived from small-angle neutron scattering measurements, 20.5(+/-0.5) Angstrom, agrees with the average R-g calculated for the NMR structures, 20.4 Angstrom, and is ca 1 Angstrom less than the value of R-g calculated for the X-ray structure. The values of the rotational anisotropy, D-parallel to/D-perpendicular to, derived from an analysis of N-15 relaxation data, range from 1.7 to 2.1, and are significantly less than the anisotropy of 2.67 predicted by hydrodynamic modeling of the crystal coordinates. In contrast, hydrodynamic modeling of the NMR coordinates yields anisotropies in the range of 1.9 to 2.7 (average 2.4(+/-0.2)), with NMR structures bent by more than 20 degrees relative the crystal structure having calculated anisotropies in best agreement with experiment. In addition, the relaxation parameters indicate that several loops in mFnFn3(9,10), including the RGD loop, are flexible on the nanosecond to picosecond time-scale. Taken together, our results suggest that, in solution, the Limited set of interactions between the mFnFn3(9,10) modules position the RGD and synergy regions to interact specifically with tell surface integrins, and at the same time permit sufficient flexibility that allows mFnFn3(9,10) to adjust for some variation in integrin structure or environment. (C) 1998 Academic Press Limited. C1 NIDR, Struct Mol Biol Unit, NIH, Bethesda, MD 20892 USA. NIDR, Craniofacial Dev Biol & Regenerat Branch, NIH, Bethesda, MD 20892 USA. US FDA, Biophys Lab, Ctr Biol Evaluat & Res, Bethesda, MD 20892 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Copie, V (reprint author), Montana State Univ, Dept Biochem & Chem, Bozeman, MT 59717 USA. OI Yamada, Kenneth/0000-0003-1512-6805 NR 59 TC 129 Z9 130 U1 0 U2 11 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD APR 3 PY 1998 VL 277 IS 3 BP 663 EP 682 PG 20 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZK501 UT WOS:000073328800013 PM 9533887 ER PT J AU Ravishankara, AR Hancock, G Kawasaki, M Matsumi, Y AF Ravishankara, AR Hancock, G Kawasaki, M Matsumi, Y TI Photochemistry of ozone: Surprises and recent lessons SO SCIENCE LA English DT Article ID RELATIVE QUANTUM YIELDS; PHOTOLYSIS; NM; O-2(A(1)DELTA(G)); O(D-1) C1 NOAA, Atmospher Chem Kinet Program, Aeron Lab, Boulder, CO 80303 USA. Univ Oxford, Phys & Theoret Chem Lab, Oxford OX1 2QZ, England. Kyoto Univ, Dept Mol Engn, Kyoto 6068501, Japan. Nagoya Univ, Grad Sch Sci, Toyokawa 4428507, Japan. Nagoya Univ, Solar Terr Environm Lab, Toyokawa 4428507, Japan. RP Ravishankara, AR (reprint author), NOAA, Atmospher Chem Kinet Program, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 13 TC 57 Z9 57 U1 2 U2 16 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 3 PY 1998 VL 280 IS 5360 BP 60 EP 61 DI 10.1126/science.280.5360.60 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZF314 UT WOS:000072885100034 ER PT J AU Saigal, A Fuller, ER Langer, SA Carter, WC Zimmerman, MH Faber, KT AF Saigal, A Fuller, ER Langer, SA Carter, WC Zimmerman, MH Faber, KT TI Effect of interface properties on microcracking of iron titanate SO SCRIPTA MATERIALIA LA English DT Article ID THERMAL-EXPANSION ANISOTROPY C1 Tufts Univ, Dept Mech Engn, Medford, MA 02155 USA. NIST, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. NIST, Informat Technol Lab, Gaithersburg, MD 20899 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. RP Saigal, A (reprint author), Tufts Univ, Dept Mech Engn, Medford, MA 02155 USA. RI Faber, Katherine/B-6741-2009; Carter, W/K-2406-2012 NR 6 TC 14 Z9 14 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD APR 3 PY 1998 VL 38 IS 9 BP 1449 EP 1453 DI 10.1016/S1359-6462(98)00040-2 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZJ947 UT WOS:000073269700020 ER PT J AU Coursey, BM Colle, R Zimmerman, BE Karam, LR Unterweger, MP Golas, DB AF Coursey, BM Colle, R Zimmerman, BE Karam, LR Unterweger, MP Golas, DB TI Standards and measurements for radionuclides used in intravascular brachytherapy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Phys Lab, Gaithersburg, MD 20899 USA. Nucl Energy Inst, Washington, DC 20014 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 2 PY 1998 VL 215 MA 040-NUCL BP U940 EP U940 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414403030 ER PT J AU Fujita, E Brunschwig, B Hambright, P Neta, P AF Fujita, E Brunschwig, B Hambright, P Neta, P TI Carbon dioxide reduction catalyzed by metalloporphyrins: Interaction of reduced iron- and cobalt porphyrins with CO2 SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Howard Univ, Dept Chem, Washington, DC 20059 USA. NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Fujita, Etsuko/D-8814-2013 NR 0 TC 0 Z9 0 U1 4 U2 7 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 2 PY 1998 VL 215 MA 083-COLL BP U427 EP U428 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414401369 ER PT J AU Gaigalas, AK Ruzgas, T Vilker, VL AF Gaigalas, AK Ruzgas, T Vilker, VL TI Electron transfer between electrodes and adsorbed proteins. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RI Ruzgas, Tautgirdas/C-4646-2008 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 2 PY 1998 VL 215 MA 326-PHYS BP U236 EP U236 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500802 ER PT J AU Glazier, SA Vanderah, DJ Plant, AL AF Glazier, SA Vanderah, DJ Plant, AL TI Electrochemical characteristics of hexaoxathiol monolayers and phospholipid/hexaoxathiol supported bilayers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Biotechnol, Biomol Mat 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 2 PY 1998 VL 215 MA 283-COLL BP U486 EP U486 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414401564 ER PT J AU Han, CC Zhou, CL Hobbie, EK AF Han, CC Zhou, CL Hobbie, EK TI Cross-link density and the strength of the binding interaction in hydrogen-bonded polymer blends. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Hobbie, Erik/C-8269-2013 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 2 PY 1998 VL 215 MA 100-PMSE BP U310 EP U310 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500998 ER PT J AU Heimer, TA Heilweil, EJ AF Heimer, TA Heilweil, EJ TI Interfacial electron injection in dye sensitized TiO2 films measured directly by time resolved infrared spectroscopy. 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. 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 2 PY 1998 VL 215 MA 423-PHYS BP U274 EP U274 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500899 ER PT J AU Hougen, JT Mekhtiev, IA AF Hougen, JT Mekhtiev, IA TI An alternative internal rotation quantum number above the torsional barrier. 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. 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 2 PY 1998 VL 215 MA 063-PHYS BP U162 EP U162 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500540 ER PT J AU Krishnamoorti, R Rai, S Hammouda, B AF Krishnamoorti, R Rai, S Hammouda, B TI Phase behavior and rheology of binary block copolymer blends SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Houston, Dept Chem Engn, Houston, TX 77204 USA. Natl Inst Stand & Technol, Cold Neutron Res Facil, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 009-PMSE BP U282 EP U282 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500910 ER PT J AU Krishnamoorti, R Hammouda, B AF Krishnamoorti, R Hammouda, B TI Effect of pressure on the phase behavior and crystallization of polyolefin blends SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Houston, Dept Chem Engn, Houston, TX 77204 USA. NIST, Cold Neutron Res Facil, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 008-PMSE BP U282 EP U282 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500909 ER PT J AU Lefebvre, AA Lee, JH Balsara, NP AF Lefebvre, AA Lee, JH Balsara, NP TI The cross-over from spinodal decomposition to nucleation and growth in polymer mixtures. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Polytech Univ, Dept Chem Engn, Brooklyn, NY 11215 USA. Natl Inst Stand & Technol, 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 2 PY 1998 VL 215 MA 131-PMSE BP U320 EP U320 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414501029 ER PT J AU Lohse, DJ Rabeony, M Garner, RT Graessley, WW Migler, K AF Lohse, DJ Rabeony, M Garner, RT Graessley, WW Migler, K TI Effect of pressure on polymer blend miscibility SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Exxon Res & Engn Co, Annandale, NJ 08801 USA. Princeton Univ, Princeton, NJ 08544 USA. 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 2 PY 1998 VL 215 MA 066-PMSE BP U300 EP U300 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500964 ER PT J AU Loomis, RA Reid, JP Leone, SR AF Loomis, RA Reid, JP Leone, SR TI Mechanisms and dynamics of alkyl radical/atom reactions determined by time-resolved fourier transform infrared emission 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. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Reid, Jonathan/D-9411-2013 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 2 PY 1998 VL 215 MA 071-PHYS BP U164 EP U164 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500548 ER PT J AU Meador, JP AF Meador, JP TI Bioavailability of tributyltin in marine sediment: A laboratory study. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 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 2 PY 1998 VL 215 MA 067-ENVR BP U587 EP U587 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414401884 ER PT J AU Poirier, GE Pylant, ED AF Poirier, GE Pylant, ED TI Molecular-scale views of the interaction of water vapor with hydroxy-terminated alkanethiol monolayers on Au(111). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. Univ Texas, Austin, TX 78712 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 2 PY 1998 VL 215 MA 246-PHYS BP U213 EP U213 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500722 ER PT J AU Pratt, KW AF Pratt, KW TI The truth about pH: A look at what is swept under the rug. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 690-CHED BP U374 EP U374 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414401208 ER PT J AU Roitberg, A Holden, M Mayhew, M Beratan, D Kurnikov, I Vilker, V AF Roitberg, A Holden, M Mayhew, M Beratan, D Kurnikov, I Vilker, V TI Binding and electron transfer between putidaredoxin and cytochrome P450cam. Theory and experiments. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 327-PHYS BP U236 EP U237 PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500803 ER PT J AU Roitberg, A Mujica, V Ratner, MA AF Roitberg, A Mujica, V Ratner, MA TI Molecular wires: Computation of the conductance decay length. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. Cent Univ Venezuela, Fac Ciencias Escuela Quim, Caracas 1020A, Venezuela. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. NR 1 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 2 PY 1998 VL 215 MA 290-PHYS BP U226 EP U226 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500766 ER PT J AU Short, JW AF Short, JW TI Distinguishing coal from petroleum-derived PAH in environmental samples. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA, Natl Marine Fisheries Serv, Juneau, AK 99801 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 2 PY 1998 VL 215 MA 043-GEOC BP U629 EP U630 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414402011 ER PT J AU Toby, BH AF Toby, BH TI Locating extra-framework species in zeolites using powder diffraction. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 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 2 PY 1998 VL 215 MA 192-INOR BP U758 EP U758 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414402420 ER PT J AU Tsang, W AF Tsang, W TI The need for computational chemistry inputs towards the understanding of the incineration of organic-phosphorus compounds SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 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 2 PY 1998 VL 215 MA 216-COMP BP U563 EP U563 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414401808 ER PT J AU Tsang, W Mokrushin, V AF Tsang, W Mokrushin, V TI Constraints to the standard RRKM treatments of unimolecular reaction under high temperature combustion conditions 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 2 PY 1998 VL 215 MA 382-PHYS BP U262 EP U262 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500858 ER PT J AU Wladkowski, BD Krauss, M Stevens, WJ AF Wladkowski, BD Krauss, M Stevens, WJ TI Phosphate-ester hydrolysis and the ribonuclease catalytic mechanism: A computation study using ab initio effective fragment potentials. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Western Maryland Coll, Dept Chem, Westminster, MD 21157 USA. Natl Inst Stand & Technol, Rockville, MD 21855 USA. Ctr Adv Res Biotechnol, Rockville, MD 21855 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 2 PY 1998 VL 215 MA 198-COMP BP U558 EP U558 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414401790 ER PT J AU Zimmerman, BE Cessna, JT Coursey, BM AF Zimmerman, BE Cessna, JT Coursey, BM TI Standardizations of radionuclides used in bone palliation therapy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST, Phys 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 2 PY 1998 VL 215 MA 039-NUCL BP U940 EP U940 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414403029 ER PT J AU Thomas, JJ Jennings, HM Allen, AJ AF Thomas, JJ Jennings, HM Allen, AJ TI Determination of the neutron scattering contrast of hydrated Portland cement paste using H2O/D2O exchange SO ADVANCED CEMENT BASED MATERIALS LA English DT Article DE cement; C-S-H; surface area; SANS ID SURFACE AB Accurate measurements of the surface area of cement based materials using small-angle neutron scattering (SANS) require determination of the neutron scattering contrast between the C-S-H gel and H2O. Because the C-S-H gel has a poorly understood structure and a variable composition, calculated values of the C-S-H:H2O neutron scattering contrast based on an assumed C-S-H chemical composition and density are subject to error. The C-S-H:H2O neutron scattering contrast was determined experimentally by measuring the change in apparent surface area as the H2O in a hydrated cement specimen was replaced with D2O, resulting in a new value of 6.78 x 10(28) m(-4). This new contrast value increases some previously reported SANS surface area values by 21%. The results also confirm that C-S-H interlayer water should be included in the solid phase whereas gel pore water should be excluded. (C) 1998 Elsevier Science Ltd. C1 Northwestern Univ, Dept Civil Engn, Evanston, IL 60208 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Thomas, JJ (reprint author), Northwestern Univ, Dept Civil Engn, 2145 Sheridan Rd, Evanston, IL 60208 USA. RI Jennings, Hamlin/B-7006-2009; Thomas, Jeffrey/B-7103-2009; OI Thomas, Jeffrey/0000-0003-2897-2023 NR 8 TC 25 Z9 25 U1 3 U2 19 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1065-7355 J9 ADV CEM BASED MATER JI Adv. Cem. Based Mater. PD APR-MAY PY 1998 VL 7 IS 3-4 BP 119 EP 122 DI 10.1016/S1065-7355(97)00086-2 PG 4 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA ZK066 UT WOS:000073281500005 ER PT J AU Fletcher, RA Small, JA Blackburn, DH AF Fletcher, RA Small, JA Blackburn, DH TI Heated inlet sampling system for removing carbonaceous aerosol SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID INSITU AB A method for separating airborne particles made of refractory materials from ambient aerosol particles has been developed. A heated inlet device was fabricated from a tube furnace and tested using aerosol produced in the laboratory and found in the ambient outdoor environment. By removing interfering particulate matter, this heated inlet increases the efficiency for microanalysis of small refractory particles. Areas of application include the analysis of mineral particles (ambient crustal dusts, asbestos, etc.) and particles from nuclear accidents. (C) 1998 American Association for Aerosol Research. C1 Natl Inst Stand & Technol, Div Surface & Microanal Sci, Gaithersburg, MD 20899 USA. NIST, Div Ceram, Gaithersburg, MD 20899 USA. RP Fletcher, RA (reprint author), Natl Inst Stand & Technol, Div Surface & Microanal Sci, Gaithersburg, MD 20899 USA. NR 20 TC 1 Z9 1 U1 2 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD APR PY 1998 VL 28 IS 4 BP 283 EP 291 DI 10.1080/02786829808965528 PG 9 WC Engineering, Chemical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZE122 UT WOS:000072759900001 ER PT J AU Schwabacher, M Ellman, T Hirsh, H AF Schwabacher, M Ellman, T Hirsh, H TI Learning to set up numerical optimizations of engineering designs SO AI EDAM-ARTIFICIAL INTELLIGENCE FOR ENGINEERING DESIGN ANALYSIS AND MANUFACTURING LA English DT Article DE case-based reasoning; decision tree induction; engineering design; numerical optimization; reformation AB Gradient-based numerical optimization of complex engineering designs offers the promise of rapidly producing better designs. However, such methods generally assume that the objective function and constraint functions are continuous, smooth, and defined everywhere. Unfortunately, realistic simulators tend to violate these assumptions, making optimization unreliable. Several decisions that need to be made in setting up an optimization, such as the choice of a starting prototype and the choice of a formulation of the search space, can make a difference in the reliability of the optimization. Machine learning can improve gradient-based methods by making these choices based on the results of previous optimizations. This paper demonstrates this idea by using machine learning for four parts of the optimization setup problem: selecting a starting prototype from a database of prototypes, synthesizing a new starting prototype, predicting which design goals are achievable, and selecting a formulation of the search space. We use standard tree-induction algorithms (C4.5 and CART). We present results in two realistic engineering domains: racing yachts and supersonic aircraft. Our experimental results show that using inductive learning to make setup decisions improves both the speed and the reliability of design optimization. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Rutgers State Univ, Dept Comp Sci, Piscataway, NJ 08855 USA. NR 35 TC 14 Z9 15 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0890-0604 J9 AI EDAM JI AI EDAM-Artif. Intell. Eng. Des. Anal. Manuf. PD APR PY 1998 VL 12 IS 2 BP 173 EP 192 PG 20 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Engineering, Manufacturing SC Computer Science; Engineering GA ZJ820 UT WOS:000073256800008 ER PT J AU Zimmerman, NM AF Zimmerman, NM TI A primer on electrical units in the Systeme International SO AMERICAN JOURNAL OF PHYSICS LA English DT Article ID STANDARDS; CONSTANT AB I examine the dissemination of the electrical units, from basic physical laws to commercial calibrations. I discuss the important distinction between realization and representation of units, which refers back to the distinction between SI (Le Systeme International d'Unites) units and practical units. I then outline the current dissemination of electrical units, heavily based on the fundamental quantum standards (Josephson voltage and quantized Hall resistance standards, as well as on a classic metrology experiment, the calculable capacitor. We will see that this chain of unit realizations is one way physicists test the accuracy of the basic physical laws. As an example of the dissemination, I also outline the transfer chain from the primary voltage standard to the factory floor. Finally, I briefly discuss some areas of current research which have the potential to induce permanent changes in the definition of SI units (in particular the kilogram), and to close the "metrology triangle." C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. RP Zimmerman, NM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 17 TC 12 Z9 12 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD APR PY 1998 VL 66 IS 4 BP 324 EP 331 DI 10.1119/1.18859 PG 8 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA ZE115 UT WOS:000072759200017 ER PT J AU Watari, S Detman, T AF Watari, S Detman, T TI In situ local shock speed and transit shock speed SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article DE interplanetary physics (flare and stream dynamics, interplanetary shocks, solar wind plasma) ID CORONAL MASS EJECTIONS; SOLAR-WIND; INTERPLANETARY SHOCKS; HELIOGRAPHIC LATITUDES; WAVES; PROPAGATION; EVOLUTION; FLARES; AU AB A useful index for estimating the transit speeds was derived by analyzing interplanetary shock observations. This index is the ratio of the in situ local shock speed and the transit speed; it is 0.6-0.9 for most observed shocks. The local shock speed and the transit speed calculated for the results of the magnetohydrodynamic simulation show good agreement with the observations. The relation expressed by the index is well explained by a simplified propagation model assuming a blast wave. For several shocks the ratio is approximately 1.2, implying that these shocks accelerated during propagation in slow-speed solar wind. This ratio is similar to that for the background solar wind acceleration. C1 Commun Res Lab, Tokyo 1848795, Japan. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Watari, S (reprint author), Commun Res Lab, 4-2-1 Nukuikita, Tokyo 1848795, Japan. NR 30 TC 10 Z9 10 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0992-7689 J9 ANN GEOPHYS-ATM HYDR JI Ann. Geophys.-Atmos. Hydrospheres Space Sci. PD APR PY 1998 VL 16 IS 4 BP 370 EP 375 DI 10.1007/s00585-998-0370-9 PG 6 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA ZL142 UT WOS:000073403000002 ER PT J AU Abraham, ERI Cornell, EA AF Abraham, ERI Cornell, EA TI Teflon feedthrough for coupling optical fibers into ultrahigh vacuum systems SO APPLIED OPTICS LA English DT Article AB We present an inexpensive, reusable method of introducing optical fibers into ultrahigh vacuum systems. A Teflon ferrule with a center-drilled hole slightly larger than the fiber diameter replaces the metal ferrules of a standard Swagelok connector. The Swagelok connector when tightened compresses the Teflon to form a vacuum seal for pressures of less than or equal to 2 x 10(-10) Torr. C1 Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Abraham, ERI (reprint author), Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Abraham, Eric/B-5729-2011 NR 1 TC 44 Z9 44 U1 1 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 1 PY 1998 VL 37 IS 10 BP 1762 EP 1763 DI 10.1364/AO.37.001762 PG 2 WC Optics SC Optics GA ZD695 UT WOS:000072713700008 PM 18273085 ER PT J AU Zimmerman, BE Cessna, JT Schima, FJ AF Zimmerman, BE Cessna, JT Schima, FJ TI The standardization of the potential bone palliation radiopharmaceutical Sn-117m(+4)DTPA SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Symposium on Measurements for Radionuclides Used for Bone Pain Palliation Therapy CY SEP 17, 1996 CL GAITHERSBURG, MARYLAND SP Council Ionizing Rad Measurements & Stand, NIST ID METASTASES; THERAPY; CANCER; SR-89 AB Solutions containing the potential bone pain palliation radionuclide Sn-117m, in chloride form and as a diethylenetriaminepentaacetate (DTPA) complex, have been standardized by 4 pi beta liquid scintillation (LS) spectrometry and 4 pi gamma-ray spectrometry. Massic activities of the stock solutions were measured in order to determine dose calibrator settings for the solutions using commercial dose calibrators. Excellent agreement in the measurement of solution massic activity between the two techniques was achieved. The massic activity of (SnCl4)-Sn-117m stock solution was found to be 38.62+/-0.23 MBq g(-1) and 38.81+/-0.94 MBq g(-1) with LS spectrometry and 4 pi gamma-ray spectrometry respectively. The respective values of the massic activity of the (117m)SnDTPA stock solution with LS spectrometry and 4 pi gamma-ray spectrometry were 39.35+/-0.23 MBq g(-1) and 39.70+/-0.96 MBq g(-1). Impurities were analyzed in several solutions and found to have emission rates on the order of 10(-4) to 10(-6) of the rate of the Sn-117m emission at the end-of-bombardment. The largest impurities dame from Sn-113 and Sn-125, the activation products of isotopic impurities present in the Sn-117 target. The relative proportions of the various impurities were found to be highly dependent upon the source of Sn-117 target material. The implications of choice of half-life used in the decay correction of Sn-117m are discussed. Published by Elsevier Science Ltd. C1 NIST, Phys Lab, Gaithersburg, MD 20899 USA. RP Zimmerman, BE (reprint author), NIST, Phys Lab, Gaithersburg, MD 20899 USA. NR 12 TC 12 Z9 15 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 1998 VL 49 IS 4 BP 317 EP 328 DI 10.1016/S0969-8043(97)00044-4 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 YZ528 UT WOS:000072263100008 PM 9519441 ER PT J AU Coursey, BM Schima, FJ Golas, DB Palabrica, OT Suzuki, A Dell, MA AF Coursey, BM Schima, FJ Golas, DB Palabrica, OT Suzuki, A Dell, MA TI Measurement standards for strontium-89 for use in bone palliation SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT Symposium on Measurements for Radionuclides Used for Bone Pain Palliation Therapy CY SEP 17, 1996 CL GAITHERSBURG, MARYLAND SP Council Ionizing Rad Measurements & Stand, NIST ID COUNTING EFFICIENCY; SR-89; Y-90 AB Strontium-89 standards have been prepared for use in calibrating instruments in the measurement chain from production in reactors to administration in the clinic or radiopharmacy. Alternate reactor production schemes were evaluated to yield high purity Sr-89 with minimum Sr-85 impurity. Following purification to remove radionuclidic impurities, samples of Sr-89 were standardized by high-efficiency liquid-scintillation counting with a relative expanded uncertainty (intended to approximate two standard deviations) of 0.48%. A Standard Reference Material, SRM 4426A, was prepared and distributed to radiopharmaceutical manufacturers and other customers. The standard sources of Sr-89 were used indifferent geometries to calibrate high purity Ge semiconductor detectors, re-entrant ionization chambers and commercial radionuclide calibrators. The latter included Capintec dose calibrators and the Capintec beta eta C(TM) NaI(Tl) scintillation counter. (C) 1998 Elsevier Science Ltd. Ali rights reserved. C1 US Dept Commerce, Ionizing Radiat Div, Phys Lab, Natl Inst Stand & Technol,Technol Adm, Gaithersburg, MD 20899 USA. Nucl Energy Inst, Washington, DC 20006 USA. Capintec Inc, Ramsey, NJ 07446 USA. RP Coursey, BM (reprint author), US Dept Commerce, Ionizing Radiat Div, Phys Lab, Natl Inst Stand & Technol,Technol Adm, Gaithersburg, MD 20899 USA. NR 19 TC 3 Z9 3 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD APR PY 1998 VL 49 IS 4 BP 335 EP 344 DI 10.1016/S0969-8043(97)00286-8 PG 10 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YZ528 UT WOS:000072263100010 PM 9519442 ER PT J AU Dunkers, JP Flynn, KM Huang, MT McDonough, WG AF Dunkers, JP Flynn, KM Huang, MT McDonough, WG TI Fourier transform near-infrared monitoring of reacting resins using an evanescent wave high-index fiber-optic sensor SO APPLIED SPECTROSCOPY LA English DT Article DE near infrared; fiber optics; composite; cure; epoxy; polyisocyanurate ID DIFFUSE REFLECTANCE SPECTROSCOPY; UREA) BLOCK COPOLYMERS; COMPOSITE; SYSTEM; IR AB In this work, a high-index silica-based fiber-optic mini-bundle sensor was constructed and implemented with a Fourier transform near-infrared spectrometer in the spectral region from 10 000 to 4500 cm(-1). The refractive index of the multimode step index fiber was 1.618. This arrangement allows the propagation of waveguiding modes when the sensor is immersed in most resin systems. The reactions of a polyisocyanurate resin system and an epoxy resin system were monitored and peak assignments were made and discussed with respect to their potential for use in real-lime analysis to he applied to cure control. Last, cure monitoring with this sensor was successfully demonstrated in a glass-reinforced resin transfer molded epoxy part. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Dunkers, JP (reprint author), NIST, Div Polymers, Quince Orchard & Clopper Rd, Gaithersburg, MD 20899 USA. NR 22 TC 12 Z9 12 U1 0 U2 6 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD APR PY 1998 VL 52 IS 4 BP 552 EP 556 DI 10.1366/0003702981943860 PG 5 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA ZM180 UT WOS:000073512700012 ER PT J AU Bushby, ST AF Bushby, ST TI Friend or foe? Communication gateways SO ASHRAE JOURNAL-AMERICAN SOCIETY OF HEATING REFRIGERATING AND AIR-CONDITIONING ENGINEERS LA English DT Article C1 NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Bushby, ST (reprint author), NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 4 TC 10 Z9 10 U1 0 U2 0 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.-Am. Soc. Heat Refrig. Air-Cond. Eng. PD APR PY 1998 VL 40 IS 4 BP 50 EP 53 PG 4 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA ZF734 UT WOS:000072927600019 ER PT J AU Key, PB Fulton, MH Layman, SL Scott, GI AF Key, PB Fulton, MH Layman, SL Scott, GI TI Azinphosmethyl exposure to grass shrimp (Palaemonetes pugio) life stages with emphasis on larval acetylcholinesterase activity SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID LETHAL C1 Charleston Lab, Natl Ocean Serv, Charleston, SC 29412 USA. RP Key, PB (reprint author), Charleston Lab, Natl Ocean Serv, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 14 TC 17 Z9 18 U1 0 U2 1 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 1998 VL 60 IS 4 BP 645 EP 650 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA ZE615 UT WOS:000072812300022 PM 9557206 ER PT J AU Rothermel, J Cutten, DR Hardesty, RM Menzies, RT Howell, JN Johnson, SC Tratt, DM Olivier, LD Banta, RM AF Rothermel, J Cutten, DR Hardesty, RM Menzies, RT Howell, JN Johnson, SC Tratt, DM Olivier, LD Banta, RM TI The Multi-center Airborne Coherent Atmospheric Wind Sensor SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID PROSPECTUS DEVELOPMENT TEAM; PLANETARY BOUNDARY-LAYER; WEATHER RESEARCH-PROGRAM; PULSED DOPPLER LIDAR; MARINE LAYER; LASER-RADAR; BACKSCATTER; AEROSOL; CONVECTION; EVOLUTION AB In 1992 the atmospheric Lidar remote sensing groups of the National Aeronautics and Space Administration Marshall Space Flight Center, the National Oceanic and Atmospheric Administration/Environmental Technology Laboratory (NOAA/ETL), and the Jet Propulsion Laboratory began a joint collaboration to develop an airborne high-energy Doppler laser radar (lidar) system for atmospheric research and satellite validation and simulation studies. The result is the Multicenter Airborne Coherent Atmospheric Wind Sensor (MACAWS), which has the capability to remotely sense the distribution of wind and absolute aerosol backscatter in three-dimensional volumes in the troposphere and lower stratosphere. A factor critical to the programmatic feasibility and technical success of this collaboration has been the utilization of existing components and expertise that were developed for previous atmospheric research by the respective institutions. For example, the laser transmitter is that of the mobile ground-based Doppler lidar system developed and used in atmospheric research for more than a decade at NOAA/ETL. The motivation for MACAWS is threefold: 1) to obtain fundamental measurements of subsynoptic-scale processes and features to improve subgrid-scale parameterizations in large-scale models, 2) to obtain datasets in order to improve the understanding of and predictive capabilities for meteorological systems on subsynoptic scales, and 3) to validate (simulate) the performance of existing (planned) satellite-borne sensors. Initial flight tests were made in September 1995; subsequent flights were made in June 1996 following system improvements. This paper describes the MACAWS instrument, principles of operation, examples of measurements over the eastern Pacific Ocean and western United States, and future applications. C1 NASA, George C Marshall Space Flight Ctr, Global Hydrol & Climate Ctr, Huntsville, AL 35806 USA. Univ Alabama, Huntsville, AL 35899 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Jet Propuls Lab, Pasadena, CA USA. RP Rothermel, J (reprint author), NASA, George C Marshall Space Flight Ctr, Global Hydrol & Climate Ctr, 977 Explorer Blvd, Huntsville, AL 35806 USA. RI Darby, Lisa/A-8037-2009; Tratt, David/A-7884-2009; Hardesty, Robert/H-9844-2013; Banta, Robert/B-8361-2008 OI Darby, Lisa/0000-0003-1271-0643; Tratt, David/0000-0002-3942-6848; NR 85 TC 27 Z9 27 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD APR PY 1998 VL 79 IS 4 BP 581 EP 599 DI 10.1175/1520-0477(1998)079<0581:TMCACA>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZK039 UT WOS:000073278800001 ER PT J AU Brandolini, A Balsley, BB Mabres, A Woodman, RF Capsoni, C D'Amico, M Ecklund, WL Hagfors, T Harper, R Heron, ML Hocking, WK Lehtinen, MS Rottger, J Sarango, MF Sato, T Stauch, RJ Vaughn, JM Wyatt, LR Zrnic, DS AF Brandolini, A Balsley, BB Mabres, A Woodman, RF Capsoni, C D'Amico, M Ecklund, WL Hagfors, T Harper, R Heron, ML Hocking, WK Lehtinen, MS Rottger, J Sarango, MF Sato, T Stauch, RJ Vaughn, JM Wyatt, LR Zrnic, DS TI Report from the International Workshop on Remote Sensing in Geophysics Using Doppler Techniques SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material ID INCOHERENT-SCATTER; RADAR; TURBULENCE; SPECTRA C1 Politecn Milan, Dipartimento Elettrotecn, I-20133 Milan, Italy. Univ Colorado, Boulder, CO 80309 USA. Univ Piura, Piura, Peru. Jicamarca Radio Observ, Lima, Peru. NOAA, Aeron Lab, Boulder, CO 80303 USA. Max Planck Inst Aeron, Katlenburg Lindau, Germany. Amoco Corp, Houston, TX USA. James Cook Univ N Queensland, Townsville, Qld 4811, Australia. Univ Western Ontario, London, ON, Canada. Sodankyla Geophys Observ, Sodankyla, Finland. EISCAT Sci Assoc, Kiruna, Sweden. Kyoto Univ, Kyoto 606, Japan. NOAA, Environm Res Lab, Boulder, CO 80303 USA. Def Res Ctr, St Malvern, England. Univ Sheffield, Sheffield, S Yorkshire, England. NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Brandolini, A (reprint author), Politecn Milan, Dipartimento Elettrotecn, Piazza Leonardo Da Vinci 32, I-20133 Milan, Italy. RI Sato, Toru/F-3818-2012; Lehtinen, Markku/A-9475-2015; OI Lehtinen, Markku/0000-0001-7794-258X; Wyatt, Lucy/0000-0002-9483-0018 NR 28 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD APR PY 1998 VL 79 IS 4 BP 643 EP 656 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZK039 UT WOS:000073278800005 ER PT J AU Helser, TE Brodziak, JKT AF Helser, TE Brodziak, JKT TI Impacts of density-dependent growth and maturation on assessment advice to rebuild depleted US silver hake (Merluccius bilinearis) stocks SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID LIFE-HISTORY; FISHERIES; SUCCESS; LARVAE; TIME; SIZE; RISK AB We examined how density-dependent growth and maturation rates would affect scientific advice to rebuild U.S. silver bake (Merluccius bilinearis) stocks to a minimum biomass threshold (SSB50) using an age-structured stochastic projection model. Uncertainty in recruitment and initial stock sizes at age was incorporated to more realistically capture the stochastic nature of the stock's dynamics through time. Performance measures including spawning stock biomass (SSBt)(t) risk (prob(SSBt< SSB50)), and fishery yields were examined under model assumptions of static life history parameters in contrast with density-dependent parameters for various constant fishing mortality rate (F) harvest policies. Model results indicated that unless compensatory mechanisms are accounted for, scientific advice may be too optimistic and lead to unrealistic expectations of F targets to achieve stock rebuilding, requiring longer rebuilding times and entailing more risk and unrealized sustainable yield. For instance, projected median southern stock SSB, exceeded the SSB50 of 104 000 metric tons (t) with 40% risk to the stock by year 20 from harvesting at F = 0.50. However, under the density-dependent assumption, median SSB, did not rebuild as expected, and after 20 years reached only 75 000 t with 85% risk to the stock. Also under this assumption, median yields increased from 9000 to 27 000 t by year 20 but were 30-40% lower than what would have been expected under density independence. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Populat Dynam Branch, Woods Hole, MA 02543 USA. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. RP Helser, TE (reprint author), Fisheries Res Inc, 2528 Gates Circle,Suite 37, Baton Rouge, LA 70809 USA. NR 32 TC 28 Z9 28 U1 0 U2 1 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 1998 VL 55 IS 4 BP 882 EP 892 DI 10.1139/cjfas-55-4-882 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA ZY881 UT WOS:000074671600012 ER PT J AU Kunkel, KE Changnon, SA Croley, TE Quinn, FH AF Kunkel, KE Changnon, SA Croley, TE Quinn, FH TI Transposed climates for study of water supply variability on the Laurentian Great Lakes SO CLIMATIC CHANGE LA English DT Article ID IMPACTS AB Hydrological models of the Great Lakes basin were used to study the sensitivity of Great Lakes water supplies to climate warming by driving them with meteorological data from four U.S. climate zones that were transposed to the basin. Widely different existing climates were selected for transposition in order to identify thresholds of change where major impacts on water supplies begin to occur and whether there are non-linear responses in the system. The climate zones each consist of 43 years of daily temperature and precipitation data for 1,000 or more stations and daily evaporation-related variables (temperature, wind speed, humidity, cloud cover) for approximately 20-35 stations. A key characteristic of these selected climates was much larger variability in interannual precipitation than currently experienced over the Great Lakes. Climate data were adjusted to simulate lake effects; however, a comparison of hydrologic results with and without lake effects showed that there was only minor effects on water supplies. C1 Illinois State Water Survey, Midwestern Climate Ctr, Champaign, IL 61820 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Kunkel, KE (reprint author), Illinois State Water Survey, Midwestern Climate Ctr, Champaign, IL 61820 USA. NR 28 TC 10 Z9 10 U1 1 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD APR PY 1998 VL 38 IS 4 BP 387 EP 404 DI 10.1023/A:1005351026653 PG 18 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZE629 UT WOS:000072813700001 ER PT J AU Croley, TE Quinn, FH Kunkel, KE Changnon, SA AF Croley, TE Quinn, FH Kunkel, KE Changnon, SA TI Great Lakes hydrology under transposed climates SO CLIMATIC CHANGE LA English DT Article ID IMPACTS AB Historical climates, based on 43 years of daily data from areas south and southwest of the Great Lakes, were used to examine the hydrological response of the Great Lakes to warmer climates. The Great Lakes Environmental Research Laboratory used their conceptual models for simulating moisture storages in, and runoff from, the 121 watersheds draining into the Great Lakes, over-lake precipitation into each lake, and the heat storages in, and evaporation from, each lake. This transposition of actual climates incorporates natural changes in variability and timing within the existing climate; this is not true for General Circulation Model-generated corrections applied to existing historical data in many other impact studies. The transposed climates lead to higher and more variable over-land evapotranspiration and lower soil moisture and runoff with earlier runoff peaks since the snow pack is reduced up to 100%. Water temperatures increase and peak earlier. Heat resident in the deep lakes increases throughout the year. Buoyancy-driven water column turnover frequency drops and lake evaporation increases and spreads more throughout the annual cycle. The response of runoff to temperature and precipitation changes is coherent among the lakes and varies quasi-linearly over a wide range of temperature changes, some well beyond the range of current GCM predictions for doubled CO2 conditions. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Illinois State Water Survey, Midwestern Climate Ctr, Champaign, IL 61820 USA. RP Croley, TE (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 18 TC 24 Z9 24 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD APR PY 1998 VL 38 IS 4 BP 405 EP 433 DI 10.1023/A:1005344010723 PG 29 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZE629 UT WOS:000072813700002 ER PT J AU Linteris, GT Burgess, DR Babushok, V Zachariah, M Tsang, W Westmoreland, P AF Linteris, GT Burgess, DR Babushok, V Zachariah, M Tsang, W Westmoreland, P TI Inhibition of premixed methane-air flames by fluoroethanes and fluoropropanes SO COMBUSTION AND FLAME LA English DT Article ID HYDROGEN AB This paper presents experimental and modeling results for laminar premixed methane-air flames inhibited by the fluoroethanes C2F6, C2HF5, and C2H2F4, and experimental results for the fluoropropanes C3F8 and C3HF7. The modeling results are in good agreement with the measurements with respect to reproducing flame speeds. For the fluoroethanes, calculated flame structures are used to determine the reaction pathways for inhibitor decomposition and the mechanisms of inhibition, as well as to explain the enhanced soot formation observed for the inhibitors C2HF5, C2H2F4, and C3HF7. The agents reduce the burning velocity of rich and stoichiometric flames primarily by raising the effective equivalence ratio and lowering the adiabatic flame temperature. For lean flames, the inhibition is primarily kinetic, since inhibitor reactions help to maintain the final temperature. The peak radical concentrations are reduced beyond that due to the temperature effect through reactions of fluorinated species with radicals. (C) 1998 by The Combustion Institute. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Massachusetts, Amherst, MA 01003 USA. RP Linteris, GT (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 57 TC 53 Z9 57 U1 1 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD APR PY 1998 VL 113 IS 1-2 BP 164 EP 180 DI 10.1016/S0010-2180(97)00216-2 PG 17 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA YW128 UT WOS:000071900700013 ER PT J AU Liu, HC Hong, TH Herman, M Chellappa, R AF Liu, HC Hong, TH Herman, M Chellappa, R TI Motion-model-based boundary extraction and a real-time implementation SO COMPUTER VISION AND IMAGE UNDERSTANDING LA English DT Article DE motion analysis; segmentation; real-time implementation ID OPTICAL-FLOW FIELDS; IMAGE VELOCITY; EDGE-DETECTION; SEGMENTATION; OPTIMIZATION AB Motion boundary extraction and optical flow computation are two subproblems of the motion recovery problem that cannot be solved independently of one another. These two problems have been treated separately. A popular recent approach uses an iterative scheme that consists of motion boundary extraction and optical flow computation components and refines each result through iteration, We present a local, noniterative algorithm that simultaneously extracts motion boundaries and computes optical how This is achieved by modeling 3-D Hermite polynomial decompositions of image sequences representing the perspective projection of 3-D general motion, Local model parameters are used to determine whether motion should be estimated or motion boundaries should be extracted at the neighborhood. A definite advantage of this noniterative algorithm is its efficiency. It is demonstrated by a real-time implementation and supporting experimental results. (C) 1998 Academic Press. C1 Natl Inst Stand & Technol, Intelligent Syst Div, Gaithersburg, MD 20899 USA. Univ Maryland, Ctr Automat Res, Dept Elect Engn, College Pk, MD 20742 USA. RP Liu, HC (reprint author), Natl Inst Stand & Technol, Intelligent Syst Div, Bldg 220,Room B124, Gaithersburg, MD 20899 USA. EM liu@cme.nist.gov; hongt@cme.nist.gov; herman@cme.nist.gov; chella@eng.umd.edu NR 49 TC 6 Z9 6 U1 2 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1077-3142 J9 COMPUT VIS IMAGE UND JI Comput. Vis. Image Underst. PD APR PY 1998 VL 70 IS 1 BP 87 EP 100 DI 10.1006/cviu.1998.0625 PG 14 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA ZJ022 UT WOS:000073171700007 ER PT J AU Logerwell, EA Hewitt, RP Demer, DA AF Logerwell, EA Hewitt, RP Demer, DA TI Scale-dependent spatial variance patterns and correlations of seabirds and prey in the southeastern Bering Sea as revealed by spectral analysis SO ECOGRAPHY LA English DT Article ID ANTARCTIC KRILL; SCHOOLING FISH; HABITAT; ISLAND; PHYTOPLANKTON; PREDATORS; ECOLOGY; BIRDS; DISTRIBUTIONS; HETEROGENEITY AB Uni-and bivariate spectral analyses of the spatial distribution of thick-billed murres Uria lomvia and acoustic estimates or prey biomass in the southeastern Bering Sea were used to examine the spatial variance patterns of a predator and its prey at multiple spatial scales. Power, phase and coherency spectra from individual transects. as well as those averaged over all transects, were examined. The average spectra; representing atemporal scale of months, showed that murres and prey had similar spatial variance patterns and were positively correlated over the range of spatial scales studied. The individual spectra. representing a temporal scale of hours, showed several patterns that were not evident in the average spectre. In particular, the transect-level analyses showed that the correlation between murres and prey was poor at spatial scales where prey variance was relatively low. This result suggests a new hypothesis to explain poor small-scale correlations between consumers and resources: resource distribution is relatively uniform at small scales resulting in only a slight increase in foraging return For consumers showing an aggregative response at these scales. The differences among spatial scales and between the average and individual spectra illustrate how ecological patterns can vary with temporal and spatial scale. C1 Univ Calif Irvine, Irvine, CA 92697 USA. SW Fisheries Sci Ctr, La Jolla, CA 92037 USA. RP Logerwell, EA (reprint author), SW Fisheries Ctr, 8604 La Jolla Shores Dr, La Jolla, CA 92037 USA. NR 49 TC 34 Z9 34 U1 2 U2 6 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0906-7590 EI 1600-0587 J9 ECOGRAPHY JI Ecography PD APR PY 1998 VL 21 IS 2 BP 212 EP 223 DI 10.1111/j.1600-0587.1998.tb00674.x PG 12 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA ZL149 UT WOS:000073403700012 ER PT J AU Gross, JL AF Gross, JL TI A connection model for the seismic analysis of welded steel moment frames SO ENGINEERING STRUCTURES LA English DT Article; Proceedings Paper CT US-Japan Seminar on Innovations in Stability Concepts and Methods for Seismic Design in Structural Steel CY JUL 15-18, 1996 CL HONOLULU, HAWAII DE brittle fracture; inelastic analysis; seismic performance; steel structures; welded connections AB An analytical approach is described for performing seismic evaluation of welded steel moment frame buildings constructed prior to the 1994 Northridge earthquake, The approach is based on an analytical model that captures the possibility of connection fracture and the subsequent loss of strength and stiffness, This connection model was developed and calibrated on the basis of laboratory experiments, It was employed in the seismic analysis of a 13-story building which experienced fractured connections in the Northridge earthquake and for which there are seismograph records and a damage survey, Results from several analyses indicate that the inelastic and fracture models are capable of predicting the behavior of steel moment frame buildings and of estimating the level of damage. (C) 1997 Elsevier Science Ltd. C1 NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Gross, JL (reprint author), NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RI Gross, Jorge/G-9138-2012 NR 19 TC 20 Z9 22 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0141-0296 J9 ENG STRUCT JI Eng. Struct. PD APR-JUN PY 1998 VL 20 IS 4-6 BP 390 EP 397 DI 10.1016/S0141-0296(97)00090-4 PG 8 WC Engineering, Civil SC Engineering GA YT275 UT WOS:000071583600017 ER PT J AU Long, ER Field, LJ MacDonald, DD AF Long, ER Field, LJ MacDonald, DD TI Predicting toxicity in marine sediments with numerical sediment quality guidelines SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE sediment quality guidelines; predictive ability; laboratory toxicity tests ID AMPHIPOD; FLORIDA; PAH AB Matching synoptically collected chemical and laboratory bioassay data (n = 1,068) were compiled from analyses of surficial sediment samples collected during 1990 to 1993 to evaluate the predictive ability of sediment quality guidelines (SQGs), specifically, effects range--low (ERL), effects range--median (ERM), threshold effects level (TEL), and probable effects level (PEL) values. Data were acquired from surveys of sediment quality performed in estuaries along the Atlantic, Pacific, and Gulf of Mexico coasts. Samples were classified as either nontoxic (p > 0.05 relative to controls), marginally toxic (p < 0.05 only), or highly toxic (p < 0.05 and response greater than minimum significant difference relative to controls). This analysis indicated that, when not exceeded, the ERLs and TELs were highly predictive of nontoxicity. The percentages of samples that were highly toxic generally increased with increasing numbers of guidelines (particularly the ERMs and PELs) that were exceeded. Also, the incidence of toxicity increased with increases in concentrations of mixtures of chemicals normalized to (divided by) the SQGs. The ERMs and PELs indicated high predictive ability in samples in which many substances exceeded these concentrations. Suggestions are provided on the uses of these estimates of the predictive ability of sediment guidelines. C1 NOAA, Coastal Monitoring & Bioeffects Assessment Div, Seattle, WA 98115 USA. NOAA, Hazardous Mat Response & Assessment Div, Seattle, WA 98115 USA. MacDonald Environm Sci Ltd, Nanaimo, BC V9X 1C6, Canada. RP Long, ER (reprint author), NOAA, Coastal Monitoring & Bioeffects Assessment Div, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 30 TC 416 Z9 487 U1 5 U2 79 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD APR PY 1998 VL 17 IS 4 BP 714 EP 727 DI 10.1897/1551-5028(1998)017<0714:PTIMSW>2.3.CO;2 PG 14 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA ZD357 UT WOS:000072677100028 ER PT J AU Ruckelshaus, MH AF Ruckelshaus, MH TI Spatial scale of genetic structure and an indirect estimate of gene flow in eelgrass, Zostera marina SO EVOLUTION LA English DT Article DE extinction; gene flow; genetic differentiation; isolation by distance; marine angiosperm; recolonization; theta; Zostera marina ID AUTO-CORRELATION ANALYSIS; GREAT-BARRIER-REEF; POPULATION-STRUCTURE; SEED DISPERSAL; NATURAL-POPULATIONS; DISTANCE; DIFFERENTIATION; PLANT; EXTINCTION; GENOTYPES AB In this study, the first investigation of population structure in an aquatic angiosperm, I show that populations of a marine angiosperm (eelgrass, Zostera marina) are genetically differentiated at a number of spatial scales. I find also that there is no correspondence between geographic and genetic distances separating subpopulations, an increasingly common result in spatially stratified studies of genetic structure in marine invertebrates. F-statistics, calculated for two years from electrophoretic variation at five polymorphic allozyme loci, indicate significant genetic differentiation among sampling quadrats within each of two bays (theta = 0.064-0.208), between tide zones within a bay (theta 0.025-0.157) and between bays (theta = 0.079). Spatial autocorrelation analysis was used to explore genetic differentiation at smaller spatial scales; estimated patch sizes (within which genetic individuals are randomly associated) indicated no appeciable genetic structure at scales less than 20 m x 20 m. Calculated values of F-statistics were a function of the spatial scale from which samples were drawn: increasing the size of the "subpopulation" included in calculation of fixation indices for the same "total" sample resulted in an increase in the magnitude of f (e.g., from 0.092 to 0.181) and a decrease in theta (e.g., from 0.186 to 0.025). On the basis of the best estimate of the spatial scale of subpopulations, the effective number of migrants per generation (N(e)m) ranges from 1.1 to 2.8. Genetic consequences of the disturbance regime in the eelgrass habitat sampled were extreme variation between years in the allele richness and proportion of heterozygotes in a sample and a positive relationship between the extinction probability of patches and the genetic variance among them. The changes in F-statistics as a function of sampling scale and the observation that theta among sampled quadrats was positively associated with the probability of extinction among quadrats indicated that indirect estimates of gene Bow (N(e)m) calculated from theta should be cautiously interpreted in populations that may not yet be in drift-migration equilibrium. C1 Univ Washington, Dept Bot, Seattle, WA 98195 USA. Florida State Univ, Dept Biol Sci, Tallahassee, FL 32306 USA. RP Ruckelshaus, MH (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd, Seattle, WA 98112 USA. EM mary.ruckelshaus@noaa.gov NR 83 TC 55 Z9 56 U1 0 U2 10 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 USA SN 0014-3820 J9 EVOLUTION JI Evolution PD APR PY 1998 VL 52 IS 2 BP 330 EP 343 DI 10.2307/2411071 PG 14 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA ZM270 UT WOS:000073521700004 ER PT J AU Ford, MJ AF Ford, MJ TI Testing models of migration and isolation among populations of chinook salmon (Oncorhynchus tschawytscha) SO EVOLUTION LA English DT Article DE coalescent; gene flow; gene genealogy; neutrality; polymorphism; population structure; straying ID POLYMERASE CHAIN-REACTION; DNA-SEQUENCE; GENE FLOW; PACIFIC SALMON; RAINBOW-TROUT; DROSOPHILA-MELANOGASTER; NUCLEOTIDE DIFFERENCES; MITOCHONDRIAL-DNA; POLYMORPHISM; TSHAWYTSCHA AB The chinook salmon (Oncorhynchus tschawytscha) is a behaviorally, morphologically, and ecologically variable species distributed over a large geographic range. Although previous genetic surveys have revealed considerable genetic differences among populations with different life history types and from different major river drainages, it is not clear to what degree these genetically distinct populations are connected by low levels of gene Bow. The work described in this paper addresses this question by surveying DNA restriction site variation at six nuclear genes from nine populations encompassing most of the species's North American range, and then attempting to fit the patterns of variation observed at these genes to five different evolutionary models using computer simulations of the coalescent process. Two commonly used constant population size models, one hypothesizing no migration among populations and one hypothesizing equal rates of migration among populations, were found to be statistically inconsistent with the observed patterns of variation. The other three models, which involved either recent divergence among populations coupled with large changes in populations size, unequal migration rates among populations, or selection, were all found to be consistent with the observed patterns of variation. Assuming selective neutrality, these results suggest that either the populations have all descended from a common ancestral population within the last similar to 50,000 years and have all suffered large declines in effective population size since that time, or that they have a more ancient divergence time but are connected by low levels of gene flow. These conclusions rest on the assumption of selective neutrality. With the methods employed, it was not possible to simultaneously test hypotheses of both selective neutrality and population structure. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Ford, MJ (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM mike.ford@noaa.gov RI Ford, Michael/K-3147-2012 NR 71 TC 27 Z9 27 U1 1 U2 6 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 USA SN 0014-3820 J9 EVOLUTION JI Evolution PD APR PY 1998 VL 52 IS 2 BP 539 EP 557 DI 10.2307/2411089 PG 19 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA ZM270 UT WOS:000073521700022 ER PT J AU Schmied, RL Ditton, RB AF Schmied, RL Ditton, RB TI Angler ethics education efforts in support of marine fisheries management in the southeastern United States SO FISHERIES LA English DT Article C1 NMFS, SE Reg Off, St Petersburg, FL USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0363-2415 J9 FISHERIES JI Fisheries PD APR PY 1998 VL 23 IS 4 BP 8 EP 9 PG 2 WC Fisheries SC Fisheries GA ZE651 UT WOS:000072815900003 ER PT J AU Edwards, EF Perkins, PC AF Edwards, EF Perkins, PC TI Estimated tuna discard from dolphin, school, and log sets in the eastern tropical Pacific Ocean, 1989-1992 SO FISHERY BULLETIN LA English DT Article AB Pressure to reduce fishery-related dolphin mortality in the tuna purse-seine fishery of the eastern tropical Pacific Ocean (ETP) may alter fishing patterns from the current situation, in which most tuna is caught in association with dolphins, to a situation in which these "dolphin sets" are replaced by sets on unassociated schools of tuna (school sets) or on floating objects (log sets). Although not likely to effect any substantial change in dolphin population dynamics, owing to current low levels of dolphin mortality, such a change in fishing pattern could damage the commercial stock of yellowfin tuna and perhaps stocks of other tuna species because, unlike dolphin sets which generate almost no unwanted catch, school and log sets capture moderate to large amounts of undersized or otherwise undesirable tuna that are subsequently discarded at sea. In this study, we examined the differences between set types (in short tons of tuna discarded per set by U.S. vessels fishing in the ETP during 1989-92) and then predicted the increase in short tons of tuna discarded per set (all tuna species combined) that would likely result from replacing the dolphin sets with an equivalent number of school or log sets (or both). Expected discard weight of tuna was 100 times higher for log sets and 10 times higher for school sets than for dolphin sets. Average expected tuna discard per set was 0.06 short tons for dolphin sets, 1.15 short tons for school sets, and 10.5 short tons for log sets. Hypothetically, redistributing all dolphin sets to log sets increased estimated average discard of tuna by the international fleet in the ETP by about 337%. A hypothetical replacement of all dolphin sets with log sets would lead to estimated discards of 10-25% of the estimated average number of yellowfin recruits to the fishery each year. If this discard is combined with an estimated 25% reduction in tons of yellowfin tuna caught that would result from concommitant changes in size structure of the landed fish (Punsley et al., 1994), the fishery could lose 30-50% of the approximately 98 million individual yellowfin tuna estimated to recruit to the fishery each year. Sustained removals of this magnitude, combined with environmental variability, could pose problems for long-term sustainability of the ETP yellowfin tuna stock; moreover, the change in fishing-effort patterns leading to this effect on yellowfin tuna would likely contribute little to recovery or sustainability of ETP dolphin stocks. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, NOAA, La Jolla, CA 92038 USA. RP Edwards, EF (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, NOAA, POB 271, La Jolla, CA 92038 USA. NR 5 TC 8 Z9 8 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1998 VL 96 IS 2 BP 210 EP 222 PG 13 WC Fisheries SC Fisheries GA ZG226 UT WOS:000072979800003 ER PT J AU Fiedler, PC Barlow, J Gerrodette, T AF Fiedler, PC Barlow, J Gerrodette, T TI Dolphin prey abundance determined from acoustic backscatter data in eastern Pacific surveys SO FISHERY BULLETIN LA English DT Article ID DOPPLER CURRENT PROFILER; ZOOPLANKTON ABUNDANCE; TROPICAL PACIFIC; TARGET STRENGTH; AGGREGATIONS; MICRONEKTON; DEPENDENCE; MIGRATION; ATLANTIC; PATTERNS AB Acoustic backscatter data from a 38-kHz echo sounder and a 150-kHz acoustic Doppler current profiler (ADCP) were collected during Southwest Fisheries Science Center marine mammal surveys in the eastern Pacific aboard the NOAA ship David Starr Jordan in 1992 and 1993. These data were processed to give profiles of volume scattering strength. A deep scattering layer dominated the time-depth patterns of backscatter. This layer migrated from a depth of 300-400 m during the day to 0-100 m at night, when it was located just above the thermocline. The source of backscatter was primarily small fish and squid, which are dolphin prey. Dolphin sighting rates were correlated positively with nighttime volume scattering strength above the thermocline. Spatial and temporal variability of prey biomass in the surface layer, as indexed by volume scattering strength, may have important consequences for dolphin feeding, as well as for distributional responses to habitat variability by dolphins. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, NOAA, La Jolla, CA 92038 USA. RP Fiedler, PC (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, NOAA, POB 271, La Jolla, CA 92038 USA. NR 44 TC 29 Z9 34 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 1998 VL 96 IS 2 BP 237 EP 247 PG 11 WC Fisheries SC Fisheries GA ZG226 UT WOS:000072979800005 ER PT J AU Landingham, JH Sturdevant, MV Brodeur, RD AF Landingham, JH Sturdevant, MV Brodeur, RD TI Feeding habits of juvenile Pacific salmon in marine waters of southeastern Alaska and northern British Columbia SO FISHERY BULLETIN LA English DT Article ID ONCORHYNCHUS-KETA; CHUM SALMON; SIZE; FOOD; KISUTCH; STRAIT; OREGON; COHO; PINK AB First ocean-year feeding habits were determined for juvenile salmon (Oncorhynchus spp.) collected with purse seines in marine waters of southeastern Alaska in 1983 and 1984 and northern British Columbia in 1984. Associated prey assemblages were sampled with neuston and plankton nets in 1984. Salmon diets included at least 30 taxa of prey. Crustaceans (principally hyperiid amphipods), fish, and tunicates were the most important prey of pink (O. gorbuscha), chum (O. Keta), and sockeye (O. nerka) salmon. Fish were the most important prey of coho (O. kisutch) and chinook (O. tshawytscha) salmon and made up the highest percentage of stomach content weight for all salmon species. Diet shifted from crustaceans in 1983 to fish in 1984 for juvenile pink, sockeye, and chum salmon. Diet overlapped significantly ((C) over cap(lambda)>0.60) between pink and sockeye salmon, pink and chum salmon, and chum and sockeye salmon. Coho salmon diet overlap was <0.60 in all paired comparisons. Nearly all (98.6%) of the 2,210 stomachs examined were at least half full. Although, in general, prey consumed were not very similar to prey observed in the environment, the composition of salmon diets was more similar to neuston collections than to zooplankton collections. C1 Natl Marine Fisheries Serv, Auke Bay Lab, Alaska Fisheries Sci Ctr, NOAA, Juneau, AK 99801 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Landingham, JH (reprint author), Natl Marine Fisheries Serv, Auke Bay Lab, Alaska Fisheries Sci Ctr, NOAA, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 34 TC 26 Z9 27 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 1998 VL 96 IS 2 BP 285 EP 302 PG 18 WC Fisheries SC Fisheries GA ZG226 UT WOS:000072979800009 ER PT J AU McBride, RS O'Gorman, JB Able, KW AF McBride, RS O'Gorman, JB Able, KW TI Interspecific comparisons of searobin (Prionotus spp.) movements, size structure, and abundance in the temperate western North Atlantic SO FISHERY BULLETIN LA English DT Article ID FISH AB Northern searobins, Prionotus carolinus, and striped searobins, P. evolans, are commonly taken in bottom trawl, pound-net, and hook- and-line fisheries of the temperate, western North Atlantic. Seasonal movements, size structure, and interannual variations in population size of both species were examined with data from three fishery-independent trawl surveys. Geographic distributions of both species overlapped year-round, but on average, northern searobins were found in colder, deeper water than were striped searobins. Northern searobins were found north and east of Cape Cod during the warmest months and northeast of Hudson Canyon during the coldest months, whereas striped searobins were rarely found in these regions during these seasons. Furthermore, northern searobins moved north and nearshore earlier in spring and left these habitats earlier in autumn. Modal size of adult northern searobins was generally between 17 and 21 cm total length, about 5 cm shorter than that of adult striped searobins. Overall, northern searobins were collected more frequently and were more numerous than striped searobins. Because they were smaller and occurred in cooler waters, however, they were not dominant by weight in coastal habitats during autumn. During the past 25-30 years, the annual population size of both species has varied by an order of magnitude, fluctuating without any clear trend. Although seasonally abundant in coastal and continental shelf waters, searobins, because of their small size in relation to other species, are usually discarded and contribute little to landings from the mid-Atlantic states. C1 Rutgers State Univ, Marine Field Stn, Inst Marine & Coastal Sci, Tuckerton, NJ 08087 USA. NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP McBride, RS (reprint author), Florida Marine Res Inst, 100 8th Ave SE, St Petersburg, FL 33701 USA. RI McBride, Richard/C-2818-2012 NR 52 TC 5 Z9 5 U1 1 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 1998 VL 96 IS 2 BP 303 EP 314 PG 12 WC Fisheries SC Fisheries GA ZG226 UT WOS:000072979800010 ER PT J AU Beckman, AT Gunderson, DR Miller, BS Buckley, RM Goetz, B AF Beckman, AT Gunderson, DR Miller, BS Buckley, RM Goetz, B TI Reproductive biology, growth, and natural mortality of Puget Sound rockfish, Sebastes emphaeus (Starks, 1911) SO FISHERY BULLETIN LA English DT Article ID VIVIPARITY C1 Ruhr Univ Bochum, Prof Hofmann Lab, Dept Zool & Parasitol, D-44801 Bochum, Germany. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. Univ Washington, Washington Dept Fish & Wildlife, Seattle, WA 98195 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Beckman, AT (reprint author), Ruhr Univ Bochum, Prof Hofmann Lab, Dept Zool & Parasitol, ND 05-344, D-44801 Bochum, Germany. EM dgun@fish.washington.edu NR 14 TC 11 Z9 12 U1 1 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD APR PY 1998 VL 96 IS 2 BP 352 EP 356 PG 5 WC Fisheries SC Fisheries GA ZG226 UT WOS:000072979800014 ER PT J AU Fernandez, S Hohn, AA AF Fernandez, S Hohn, AA TI Age, growth, and calving season of bottlenose dolphins, Tursiops truncatus, off coastal Texas SO FISHERY BULLETIN LA English DT Article ID EASTERN TROPICAL PACIFIC; NOSED DOLPHINS; STENELLA-ATTENUATA; REPRODUCTION; MATURITY; FLORIDA C1 Inst Tecnol & Estudios Super Monterrey, Guaymas 85400, Sonora, Mexico. Natl Marine Fisheries Serv, Off Protected Resources, NOAA, Silver Spring, MD 20910 USA. RP Fernandez, S (reprint author), Inst Tecnol & Estudios Super Monterrey, Campus Guaymas,Apdo Postal 484, Guaymas 85400, Sonora, Mexico. EM hohn@noaa.gov RI Hohn, Aleta/G-2888-2011 OI Hohn, Aleta/0000-0002-9992-7062 NR 35 TC 35 Z9 45 U1 1 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 1998 VL 96 IS 2 BP 357 EP 365 PG 9 WC Fisheries SC Fisheries GA ZG226 UT WOS:000072979800015 ER PT J AU Garrett, ES Jahncke, ML Cole, EA AF Garrett, ES Jahncke, ML Cole, EA TI Effects of Codex and GATT SO FOOD CONTROL LA English DT Article; Proceedings Paper CT 1st International Food Safety / HACCP Conference CY FEB 17-18, 1997 CL NOORDWIJK, NETHERLANDS DE trade; global food safety; technical barriers AB The role of the WHO/FAO Food Standards Programme has become increasingly important since the Uruguay Round of GATT since adherence to Coder Standards offers safe harborage in WTO disputes. This paper reviews some of the Programme's history and successes, discusses Coder's changing role due to GATT and WTO's endorsement of its work products, and discusses HACCP and other topical issues. It also details where the Coder Programme is in relation to streamlining its activities in terms of emphasizing the role of science in its deliberations, accelerating the timeliness of its activities, and recasting its recommendations for national government acceptance of its standards. (C) 1998 Elsevier Science Ltd. AIL rights reserved. C1 Natl Marine Fisheries Serv, Natl Seafood Inspect Lab, Pascagoula, MS USA. Virginia Seafood Res & Extens Ctr, Hampton, VA 23669 USA. RP Garrett, ES (reprint author), Natl Marine Fisheries Serv, Natl Seafood Inspect Lab, 3209 Frederic St, Pascagoula, MS USA. NR 22 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0956-7135 J9 FOOD CONTROL JI Food Control PD APR-JUN PY 1998 VL 9 IS 2-3 BP 177 EP 182 DI 10.1016/S0956-7135(98)80004-2 PG 6 WC Food Science & Technology SC Food Science & Technology GA ZY583 UT WOS:000074638200020 ER PT J AU Huaman, MM Balsley, BB AF Huaman, MM Balsley, BB TI Long-term-mean aspect sensitivity of PMSE determined from poker flat MST radar data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIO-WAVE SCATTERERS; VHF-RADAR; POLAR MESOSPHERE; ANDENES 69-DEGREES-N,16-DEGREES-E; SUMMER ECHOES; STRATOSPHERE; TROPOSPHERE; REFLECTION; JICAMARCA; NORWAY AB Results of a long-term study of aspect sensitivity of Polar Mesosphere Summer Echoes (PMSE) are presented using archived Poker Flat MST radar (65 degrees 08'N; 147 degrees 27'W) data. We have used data from the PMSE region (80- to 90-km) during the months of June and July for the years 1981-84, when three antenna beams were available, one beam pointing vertical and two beams pointing 15 degrees off-vertical. Comparisons of calibrated vertical and 15 degrees off-vertical monthly-average echo power profiles for each of the summer months show that VHF scattering from PMSE is strongly aspect sensitive at the lowest heights (similar to 80 km), and exhibits a clear decrease of aspect sensitivity with increasing height. Comparison of monthly-average aspect sensitivity profiles during the four-year period shows a reasonable consistency throughout the years. The composite four-year-average aspect sensitivity profile for the months of June and July data suggests a strong tendency to isotropy at the higher mesospheric heights. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Huaman, MM (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Campus Box 216, Boulder, CO 80309 USA. NR 26 TC 14 Z9 14 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 1998 VL 25 IS 7 BP 947 EP 950 DI 10.1029/98GL00708 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZE646 UT WOS:000072815400003 ER PT J AU Webster, CR May, RD Michelsen, HA Scott, DC Wilson, JC Jonsson, HH Brock, CA Dye, JE Baumgardner, D Stimpfle, RM Koplow, JP Margitan, JJ Proffitt, MH Jaegle, L Herman, RL Hu, H Flesch, GJ Loewenstein, M AF Webster, CR May, RD Michelsen, HA Scott, DC Wilson, JC Jonsson, HH Brock, CA Dye, JE Baumgardner, D Stimpfle, RM Koplow, JP Margitan, JJ Proffitt, MH Jaegle, L Herman, RL Hu, H Flesch, GJ Loewenstein, M TI Evolution of HCl concentrations in the lower stratosphere from 1991 to 1996 following the eruption of Mt. Pinatubo SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SULFATE AEROSOLS; MOUNT-PINATUBO; CHLORINE; NO2; SPECTROMETER; AIRCRAFT; HNO3; CLO; CHEMISTRY AB In situ measurements of hydrochloric acid in the lower stratosphere reveal that its mean abundance relative to that of total inorganic chlorine (Cl-y) has evolved upwards from HCl/Cl-gamma=40% in late 1991 to 70% in 1996. This fraction is generally anticorrelated with aerosol surface area concentration, which has been diminishing since the 1991 volcanic eruption of Mt. Pinatubo. Calculations incorporating new laboratory results of faster heterogeneous chemistry show that air parcels with high aerosol loading exposed to temperatures below 205 K can experience enough chlorine activation to drive the HCl/Cl-y below 50%, but overestimate observed ClO/Cl-y. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Denver, Dept Engn, Denver, CO 80208 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Harvard Univ, Dept Chem, Cambridge, MA 02138 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Webster, CR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Brock, Charles/G-3406-2011; Herman, Robert/H-9389-2012 OI Brock, Charles/0000-0002-4033-4668; Herman, Robert/0000-0001-7063-6424 NR 31 TC 18 Z9 18 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 1998 VL 25 IS 7 BP 995 EP 998 DI 10.1029/98GL00548 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZE646 UT WOS:000072815400016 ER PT J AU Assel, RA AF Assel, RA TI The 1997 ENSO event and implication for North American Laurentian Great Lakes winter severity and ice cover SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Mild winters and below-average annual maximum ice cover for the Laurentian Great Lakes occur during strong warm ENSO events. During the six strongest warm ENSO events since 1950 a Great Lakes winter severity temperature index and simulated annual maximum ice cover averaged 1.2 degrees C above and 15% below a 1950-1994 average, respectively. The observed differences between the average of the strong ENSO event years and the base period average are statistically significant. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Assel, RA (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 11 TC 19 Z9 19 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 1998 VL 25 IS 7 BP 1031 EP 1033 DI 10.1029/98GL00720 PG 3 WC Geosciences, Multidisciplinary SC Geology GA ZE646 UT WOS:000072815400025 ER PT J AU Haywood, JM Ramaswamy, V Donner, LJ AF Haywood, JM Ramaswamy, V Donner, LJ TI Comments on "A limited-area-model case study of the effects of sub-grid scale variations in relative humidity and cloud upon the direct radiative forcing of sulfate aerosol" - Reply SO GEOPHYSICAL RESEARCH LETTERS LA English DT Editorial Material C1 Princeton Univ, AOS Program, Princeton, NJ 08544 USA. Geophys Fluid Dynam Lab, Princeton, NJ USA. RP Haywood, JM (reprint author), DERA, Res Flight, Farnborough GU14 0LX, Hants, England. NR 2 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 1998 VL 25 IS 7 BP 1041 EP 1041 DI 10.1029/98GL00518 PG 1 WC Geosciences, Multidisciplinary SC Geology GA ZE646 UT WOS:000072815400028 ER PT J AU Francis, O Niebauer, TM Sasagawa, G Klopping, F Gschwind, J AF Francis, O Niebauer, TM Sasagawa, G Klopping, F Gschwind, J TI Calibration of a superconducting gravimeter by comparison with an absolute gravimeter FG5 in Boulder SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GRAVITY MEASUREMENTS AB This paper reports the results of a calibration of a superconducting gravimeter using simultaneous measurements of Earth tides with an absolute gravimeter. Nine consecutive days of observations were made with both the C024 superconducting gravimeter and the FG5-202 absolute gravimeter at the NOAA Table Mountain Gravity Observatory near Boulder, Colorado. The precision of the calibration factor is better than 0.1%. The calibration factor obtained in this fashion agrees well with that obtained from a moving platform. This experiment provides a noise estimate for both the superconducting and absolute gravimeter. In addition, the local air pressure admittances of both instruments compare well with a value close to -0.35 mu Gal/mbar. C1 Observ Royal Belgique, B-1180 Brussels, Belgium. Colorado Sch Mines, Dept Phys, Golden, CO 80401 USA. NOAA, Natl Ocean Serv, Geosci Lab, Off Ocean & Earth Sci, Longmont, CO 80503 USA. Microg Solut Inc, Erie, CO 80516 USA. RP Francis, O (reprint author), Observ Royal Belgique, Ave Circulaire 3, B-1180 Brussels, Belgium. NR 12 TC 27 Z9 31 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 1998 VL 25 IS 7 BP 1075 EP 1078 DI 10.1029/98GL00712 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZE646 UT WOS:000072815400037 ER PT J AU Kirsch, RA AF Kirsch, RA TI SEAC and the start of image processing at the National Bureau of Standards SO IEEE ANNALS OF THE HISTORY OF COMPUTING LA English DT Article AB The National Bureau of Standards Electronic Automatic Computer, SEAC, completed in 1950, was the first electronic computer with an internally stored program in the U.S. government. This paper describes how scanning and computer processing of images began at the National Bureau of Standards in 1956 and how the use of SEAC made possible experiments that led to the widespread use of image processing and many other computer innovations. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kirsch, RA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 41 TC 6 Z9 6 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 1058-6180 J9 IEEE ANN HIST COMPUT JI IEEE Ann. Hist. Comput. PD APR-JUN PY 1998 VL 20 IS 2 BP 7 EP 13 DI 10.1109/85.667290 PG 7 WC Computer Science, Theory & Methods; History & Philosophy Of Science SC Computer Science; History & Philosophy of Science GA ZJ649 UT WOS:000073237800002 ER PT J AU Beichl, I Sullivan, F AF Beichl, I Sullivan, F TI Interleave in peace, or interleave in pieces SO IEEE COMPUTATIONAL SCIENCE & ENGINEERING LA English DT Article C1 NIST, Comp & Appl Math Lab, Gaithersburg, MD 20899 USA. Inst Def Anal, Ctr Comp Sci, Bowie, MD USA. RP Beichl, I (reprint author), NIST, Comp & Appl Math Lab, Gaithersburg, MD 20899 USA. NR 1 TC 3 Z9 3 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 1070-9924 J9 IEEE COMPUT SCI ENG JI IEEE Comput. Sci. Eng. PD APR-JUN PY 1998 VL 5 IS 2 BP 92 EP 96 DI 10.1109/99.683746 PG 5 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Mathematics, Applied SC Computer Science; Engineering; Mathematics GA ZV451 UT WOS:000074305900011 ER PT J AU Skinner, JP Kent, BM Wittmann, RC Mensa, DL Andersh, DJ AF Skinner, JP Kent, BM Wittmann, RC Mensa, DL Andersh, DJ TI Normalization and interpretation of radar images SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE radar imaging AB Calibrated radar images are often quantified as radar cross section. This interpretation, which is not strictly correct, can lead to misunderstanding of test target scattering properties. To avoid confusion, we recommend that a term such as "scattering brightness" (defined below) be adopted as a standard label for image-domain data. C1 AF Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. USAF, Res Lab, Signature Technol Off, Wright Patterson AFB, OH 45433 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. USN, Ctr Weap, Pt Mugu, CA USA. Demaco Inc, Champaign, IL 61820 USA. RP Skinner, JP (reprint author), Dept AF, Wright Patterson AFB, OH USA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD APR PY 1998 VL 46 IS 4 BP 502 EP 506 DI 10.1109/8.664113 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA ZG443 UT WOS:000073002800006 ER PT J AU Baker-Jarvis, J Janezic, MD Jones, CA AF Baker-Jarvis, J Janezic, MD Jones, CA TI Shielded open-circuited sample holder for dielectric measurements of solids and liquids SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE capacitor; coaxial line; dielectric constant; liquids; loss factor; microwave measurements; open circuit; permittivity measurement ID COAXIAL LINE SENSOR AB This paper presents a technique for permittivity measurements that can be used for either liquids or solid coaxial samples from near de to gigahertz frequencies. The method uses both a full-mode model of a coaxial open-circuited termination and a capacitive method for permittivity determination. The method requires the use of an impedance bridge and a network analyzer. Measurements indicate good accuracy for the permittivity over a very wide band of frequencies. For high permittivity materials the sample surfaces must be metalized. An uncertainty analysis is also presented. C1 Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder, CO 80303 USA. RP Baker-Jarvis, J (reprint author), Natl Inst Stand & Technol, Radio Frequency Technol Div, 325 Broadway, Boulder, CO 80303 USA. NR 13 TC 36 Z9 36 U1 1 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 1998 VL 47 IS 2 BP 338 EP 344 DI 10.1109/19.744172 PG 7 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 166CC UT WOS:000078557800001 ER PT J AU Coursey, BM Colle, R Zimmerman, BE Cessna, JT Golas, DB AF Coursey, BM Colle, R Zimmerman, BE Cessna, JT Golas, DB TI National radioactivity standards for beta-emitting radionuclides used in intravascular brachytherapy SO INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS LA English DT Article; Proceedings Paper CT Symposium on Advances in Cardiovascular Radiation Therapy CY FEB 20-21, 1997 CL WASHINGTON, D.C. DE radioactivity standards; beta particles; intravascular brachytherapy; liquid scintillation counting ID COUNTING EFFICIENCY; Y-90 AB The uses of beta-particle emitting radionuclides in therapeutic medicine are rapidly expanding, To ensure the accurate assays of these nuclides prior to administration, radioactivity standards are needed. The National Institute of Standards and Technology (NIST), the national metrological standards laboratory for the United States, uses high-efficiency liquid scintillation counting to standardize solutions of such beta emitters, including P-32, Sr-90/Y-90, and Re-188, Additional measurements are made on radionuclidic impurities, half lives, and other decay-scheme parameters (such as branching decay ratios or gamma-ray abundances) using HPGe detectors and reentrant ionization chambers. Following such measurements at NIST, standards are disseminated in three ways: Standard Reference Materials (SRMs), calibrations for source manufacturers, and calibration factors for commercial instruments, Uncertainties in the activity calibrations for these nuclides are of the order of +/-0.5% (at approximately 1-standard deviation confidence intervals). (C) 1998 Elsevier Science Inc. C1 Natl Inst Stand & Technol, Ioninzing Radiat Div, Phys Lab, Gaithersburg, MD 20899 USA. Nucl Energy Inst, Washington, DC 20002 USA. RP Coursey, BM (reprint author), Natl Inst Stand & Technol, Ioninzing Radiat Div, Phys Lab, Gaithersburg, MD 20899 USA. NR 25 TC 12 Z9 12 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3016 J9 INT J RADIAT ONCOL JI Int. J. Radiat. Oncol. Biol. Phys. PD APR 1 PY 1998 VL 41 IS 1 BP 207 EP 216 DI 10.1016/S0360-3016(98)00012-1 PG 10 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA ZM005 UT WOS:000073495200027 PM 9588935 ER PT J AU Fine, J Szymonski, M Kolodziej, J Yoshitake, M Franzreb, K AF Fine, J Szymonski, M Kolodziej, J Yoshitake, M Franzreb, K TI Collisional electron-capture processes at sodium halide surfaces SO IZVESTIYA AKADEMII NAUK SERIYA FIZICHESKAYA LA English DT Article; Proceedings Paper CT XIII International Conference on Ion-Surface Interaction CY SEP 01-05, 1997 CL ZVENIGOROD, RUSSIA ID ION-BOMBARDED SURFACES; ATOM COLLISIONS; AUGER; EMISSION; DEEXCITATION; EXCITATION; IMPACT; SPECTROSCOPY; METALS; STATES AB A new class of inelastic collisional excitation processes accounts for the electron spectra of ion-bombarded sodium halide surfaces. These spectra indicate that the excitation-deexcitation process consists of a sequence of lattice-ion collisions in which localized electron transfer occurs. Such collisional processes demonstrate how collisions can initiate electronic change in molecular compounds and that electron-transfer processes must play an essential role in chemistry activated by energetic collisions. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Jagiellonian Univ, Inst Phys, PL-30549 Krakow, Poland. RP Fine, J (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 33 TC 0 Z9 0 U1 0 U2 0 PU MEZHDUNARODNAYA KNIGA PI MOSCOW PA 39 DIMITROVA UL., MOSCOW, 113095, RUSSIA SN 1026-3489 J9 IZV AKAD NAUK FIZ+ JI Izv. Akad. Nauk Ser. Fiz. PD APR PY 1998 VL 62 IS 4 BP 790 EP 796 PG 7 WC Physics, Multidisciplinary SC Physics GA 119XP UT WOS:000075923900019 ER PT J AU Winchester, MR AF Winchester, MR TI Development of a method for the determination of phosphorus in copper alloys using radiofrequency glow discharge optical emission spectrometry SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE copper alloys; elemental analysis; glow discharge optical emission spectrometry; non-metallic elements; phosphorus; radiofrequency AB A method for the determination of P in Cu alloys using radiofrequency glow discharge optical emission spectrometry is developed and demonstrated. The results indicate that the method is capable of reliable determinations. The 95% confidence interval for the limit of detection (LOD) is found to be 1.6 +/- 0.4 mg kg(-1). This LOD is competitive with those provided by commonly employed analytical methodologies. C1 NIST, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Winchester, MR (reprint author), NIST, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 19 TC 6 Z9 6 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD APR PY 1998 VL 13 IS 4 BP 235 EP 242 DI 10.1039/a707526j PG 8 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA ZG823 UT WOS:000073043500003 ER PT J AU Agamalian, M Christen, DK Drews, AR Glinka, CJ Matsuoka, H Wignall, GD AF Agamalian, M Christen, DK Drews, AR Glinka, CJ Matsuoka, H Wignall, GD TI Surface-induced parasitic scattering in Bonse-Hart double-crystal diffractometers SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID SMALL-ANGLE SCATTERING; X-RAY-SCATTERING; CAMERA AB Bonse-Hart double-crystal diffractometers (DCD) with multibounce channel-cut crystals show rocking curves which depart dramatically in their wings from dynamical diffraction theory. This intrinsic background is many orders of magnitude higher than the predictions of dynamical diffraction theory. This effect has been studied at the ultra-small-angle neutron scattering (USANS) facility at Oak Ridge National Laboratory by the measurement of rocking curves from different volume elements of a thick single-bounce Si(111) perfect crystal and from triple-bounce channel-cut Si(111) crystals. Analysis of these data, together with the rocking curves from an X-ray Bonse-Hart DCD, allows it to be established that the rocking curve of the multibounce channel-cut crystals contains parasitic scattering generated at the surface of the crystals. The intensity of this component can be reduced by very deep etching of the crystal surface. Using this technique, the signal-to-noise ratio of the Bonse-Hart DCD at the ORNL USANS facility has been improved by one order of magnitude to similar to 5 X 10(5) [I(0)/I(theta = 10 ")]. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Kyoto Univ, Dept Polymer Chem, Kyoto 60601, Japan. RP Agamalian, M (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. OI Agamalian, Michael/0000-0002-9112-2534 NR 18 TC 33 Z9 34 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD APR 1 PY 1998 VL 31 BP 235 EP 240 DI 10.1107/S0021889897014581 PN 2 PG 6 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA ZW506 UT WOS:000074417800016 ER PT J AU McKendry, IG Steyn, DG Banta, RM Strapp, W Anlauf, K Pottier, J AF McKendry, IG Steyn, DG Banta, RM Strapp, W Anlauf, K Pottier, J TI Daytime photochemical pollutant transport over a tributary valley lake in southwestern British Columbia SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID OZONE CONCENTRATIONS; AIR-POLLUTION; SEA-BREEZE; LAYER; VANCOUVER; SURFACE; MODEL AB Tethersonde, lidar, aircraft, and surface chemistry measurements from an intensive field campaign (Pacific '93) in the Lower Fraser Valley (LFV) demonstrate the daytime advection of pollutants into a lake-filled valley adjoining a broad urbanized coastal valley. On three separate days (immediately before, during, and after a pollutant episode), elevated concentrations of ozone (O-3) in the narrow tributary valley could be attributed to the advection of pollutants northward from sources in the LFV (primarily metropolitan Vancouver). On 5 August, the highest concentrations of O-3 observed in the region during the entire episode were observed over the tributary lake. Simple Lagrangian mass budget calculations suggest that the unusually high concentrations observed on 5 August over the lake were physically reasonable and consistent with the known chemistry of the air advected into the valley. They also indicate that reductions in O-3 flux divergence during the overlake trajectory in the Pitt Valley, primarily as a result of reduced surface deposition, may contribute to the relatively high concentrations observed in the tributary valley. Observations immediately after the episode show that chemically aged polluted air masses can persist within the tributary valleys from the previous day. These results have implications for the understanding of air pollution in other regions of complex terrain ana show that the predominance of daytime upvalley pollutant transport in such tributary valleys is likely to have significant impacts on the local ecology and visibility. C1 Univ British Columbia, Dept Geog, Atmospher Sci Programme, Vancouver, BC V6T 1Z2, Canada. NOAA, Environm Technol Lab, Boulder, CO USA. Atmospher Environm Serv, Cloud Phys Res Div, Downsview, ON, Canada. Environm Canada, Environm Conservat Branch, Vancouver, BC, Canada. RP McKendry, IG (reprint author), Univ British Columbia, Dept Geog, Atmospher Sci Programme, 251-1984 W Mall, Vancouver, BC V6T 1Z2, Canada. RI Banta, Robert/B-8361-2008 NR 23 TC 18 Z9 18 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD APR PY 1998 VL 37 IS 4 BP 393 EP 404 DI 10.1175/1520-0450(1998)037<0393:DPPTOA>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZD977 UT WOS:000072744700005 ER PT J AU Kvardakov, VV Chen-Mayer, HH Mildner, DFR Somenkov, VA AF Kvardakov, VV Chen-Mayer, HH Mildner, DFR Somenkov, VA TI Cold neutron incoherent scattering for hydrogen detection in industrial materials SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GAMMA-ACTIVATION-ANALYSIS; COMPRESSOR BLADES; TITANIUM-ALLOYS AB Neutron incoherent scattering (NIS) is proposed as a method for the rapid detection of hydrogen and corrosion in industrial materials. As an example, we apply the NIS method to the detection of hydrogen in graphite and in titanium alloy, and compare the results with those obtained with the prompt gamma activation analysis (PGAA) method, The scattering cross section for hydrogen is much greater than the capture cross section, which enables the NIS method to have a detection limit and accuracy close to that for PGAA, and allows real time experiments on hydrogen detection to be performed. We report preliminary results on using the NIS method to determine hydrogen in urea [CO(NH2)(2)]/graphite and in titanium matrices. (C) 1998 American Institute of Physics. [S0021-8979(98)04207-8]. C1 NIST, Gaithersburg, MD 20899 USA. Russian Res Ctr, Kurchatov Inst, Moscow 123182, Russia. RP Kvardakov, VV (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 17 TC 7 Z9 7 U1 3 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 1 PY 1998 VL 83 IS 7 BP 3876 EP 3879 DI 10.1063/1.366620 PG 4 WC Physics, Applied SC Physics GA ZD971 UT WOS:000072744100068 ER PT J AU Gossard, EE Wolfe, DE Moran, KP Paulus, RA Anderson, KD Rogers, LT AF Gossard, EE Wolfe, DE Moran, KP Paulus, RA Anderson, KD Rogers, LT TI Measurement of clear-air gradients and turbulence properties with radar wind profilers SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID REFRACTIVE-INDEX; BOUNDARY-LAYER; TEMPERATURE; ATMOSPHERE; STABILITY; SPECTRUM; RASS AB An experiment comparing balloon and profiler observations was carried out to evaluate the capability of Doppler radar wind profilers to remotely measure useful meteorological quantities other than wind. The site chosen was in Southern California during a time of year when it offers a natural laboratory for investigating extreme contrasts in temperature and humidity. To evaluate the new capabilities, it was found that new and additional treatment of the radar data was necessary. For example, the adequacy of the usual radar wind observations obtained by editing the Doppler spectral moments was found to be very questionable for shortterm observations, so the authors extended the editing to the raw spectra, and substantial improvement was found. The advantages of the redundancy in five-beam systems are investigated and are also found to be very necessary to obtain the accuracy needed. A technique for minimizing the variances of the differences of the four redundant pairs of radials is described. The resulting improved vertical velocity estimates substantially improve the agreement between radio acoustic sounding system (RASS) temperature retrievals and balloon-measured temperatures. The ability of the profilers to measure turbulence intensity was rested, and the accuracy of techniques using the spectral width to measure turbulent dissipation rate when complicated spectra are present is examined. Two different techniques for optimizing the calculation of spectral width are compared and the errors assessed. One technique integrates over the uncontaminated range of the chosen spectral peak and then extrapolates a Gaussian function to infinity. The other method uses the slope of the log least squares best fit of the uncontaminated points to a Gaussian function. Profiler-measured length scales of wind and scalar quantities are measured and compared. Profiles of radar-measured gradients of refractive index are compared with gradients measured by balloon. It is shown how gradients of humidity can be calculated to about the same accuracy as refractive-index gradients by combining the temperature gradients from RASS with the refractive-index gradient observations from the radar. C1 Univ Colorado, Environm Technol Lab, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. NOAA ERL, Environm Technol Lab, Boulder, CO USA. USN, Command Control & Ocean Surveillance Ctr, San Diego, CA 92152 USA. RP Gossard, EE (reprint author), Univ Colorado, Environm Technol Lab, NOAA, Cooperat Inst Res Environm Sci, R-E-ET4,325 Broadway, Boulder, CO 80303 USA. EM egossard@etl.moaa.gov NR 54 TC 38 Z9 40 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD APR PY 1998 VL 15 IS 2 BP 321 EP 342 DI 10.1175/1520-0426(1998)015<0321:MOCAGA>2.0.CO;2 PG 22 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA ZD426 UT WOS:000072684000001 ER PT J AU Edson, JB Hinton, AA Prada, KE Hare, JE Fairall, CW AF Edson, JB Hinton, AA Prada, KE Hare, JE Fairall, CW TI Direct covariance flux estimates from mobile platforms at sea SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID INERTIAL-DISSIPATION METHOD; SURFACE WIND STRESS; OPEN-OCEAN; HEAT-FLUX; TEMPERATURE; INTERFACE; SPECTRA; LAYER AB This paper describes two methods for computing direct covariance fluxes from anemometers mounted on moving platforms at sea. These methods involve the use of either a strapped-down or gyro-stabilized system that are used to compute terms that correct for the 1) instantaneous tilt of the anemomter due to the pitch, roll, and heading variations of the platform; 2) angular velocities at the anemometer due to rotation of the platform about its local coordinate system axes; and 3) translational velocities of the platform with respect to a fixed frame of reference. The paper provides a comparison of fluxes computed with three strapped-down systems from two recent field experiments. These comparisons shows that the direct covariance fluxes are in good agreement with fluxes derived using the bulk aerodynamic method. Additional comparisons between the ship system and the research platform FLIP indicate that flow distortion systematically increases the momentum flux by 15%. Evidence suggests that this correction is appropriate for a commonly used class of research vessels. The application of corrections for both motion contamination and how distortion results in direct covariance flux estimates with an uncertainty of approximately 10%-20%. C1 Woods Hole Oceanog Inst, AOP&E Dept, Woods Hole, MA 02543 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Environm Technol Lab, Boulder, CO USA. RP Edson, JB (reprint author), Woods Hole Oceanog Inst, AOP&E Dept, Bigelow 3, Woods Hole, MA 02543 USA. NR 33 TC 151 Z9 160 U1 0 U2 13 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD APR PY 1998 VL 15 IS 2 BP 547 EP 562 DI 10.1175/1520-0426(1998)015<0547:DCFEFM>2.0.CO;2 PG 16 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA ZD426 UT WOS:000072684000016 ER PT J AU Ivkov, R Forbes, JG Greer, SC AF Ivkov, R Forbes, JG Greer, SC TI The polymerization of actin: Study by small angle neutron scattering SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NONSYMMETRIC TRICRITICAL POINTS; LIQUID SULFUR SOLUTIONS; LIVING POLYMERS; EQUILIBRIUM POLYMERIZATION; PROTEIN SUBUNITS; MUSCLE ACTIN; F-ACTIN; LIGHT-SCATTERING; RATE CONSTANTS; HEAT-CAPACITY AB We report measurements of small angle neutron scattering from solutions of rabbit muscle G-actin at 3.00 mg/mL in D2O buffer solution, with [Ca2+]=0.52 mM and with [KCl]=15, 8.9, and 5.4 mM. We observe the onset of the polymerization of G-actin to F-actin as the temperature is increased. The polymerization takes place on a time scale of 30-45 min for each temperature jump of 2 degrees C-3 degrees C. As the temperature is increased further, the average size of the polymers increases, and the characteristic length scale (or correlation length), xi, of the F-actin in the dilute solution grows: xi is about 10 Angstrom below T-p, and about 70 Angstrom a few degrees above T-p. The transition is sharper for lower concentrations of KCl. For the sample with [KCl]=8.9 mM, we observe a peak in xi at about 2 degrees C above T-p, which indicates a crossover into the semidilute regime. The transition is essentially reversible, but shows evidence of incomplete depolymerization on cycling. We are unable to apply the available theoretical model for reversible polymerization to rabbit muscle actin because of a lack of information on the enthalpy and entropy of polymerization. However, our observations for rabbit muscle actin are quite analogous to observations on the equilibrium polymerization of alpha-methylstyrene [A. P. Andrews, K. P. Andrews, S. C. Greer, F. Boue, and P. Pfeuty, Macromolecules 27, 3902 (1994)]. (C) 1998 American institute of Physics. [S0021-9606(98)50113-4]. C1 Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Univ Maryland, Dept Chem Engn, College Pk, MD 20742 USA. RP Ivkov, R (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RI Ivkov, Robert/A-3902-2015 OI Ivkov, Robert/0000-0002-2930-5276 NR 88 TC 13 Z9 13 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 1 PY 1998 VL 108 IS 13 BP 5599 EP 5607 DI 10.1063/1.475948 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZD913 UT WOS:000072738000051 ER PT J AU Kent, MS Majewski, J Smith, GS Lee, LT Satija, S AF Kent, MS Majewski, J Smith, GS Lee, LT Satija, S TI Tethered chains in theta solvent conditions: An experimental study involving Langmuir diblock copolymer monolayers SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GRAFTED POLYMERIC BRUSHES; NEUTRON REFLECTIVITY; MOLECULAR-DYNAMICS; DENSITY PROFILE; POOR SOLVENTS; MONTE-CARLO; LAYERS; TRANSITION; SIMULATION; COLLAPSE AB Langmuir monolayers of polydimethylsiloxane-polystyrene (PDMS-PS) diblock copolymers on dioctyl phthalate (DOP) at 22 degrees C are employed as a model tethered chain system in theta solvent conditions. The segmental concentration profile of the tethered PS block is obtained over an order of magnitude in both surface density (sigma) and molecular weight (M) by neutron reflection. A depletion layer of PS segments is observed at the air-liquid interface which increases with M and is independent of sigma. The variation of the tethered layer height with sigma and M is consistent with h similar to sigma(0.18)M(0.74) over the range of reduced surface density (sigma pi R-g(2)) from 1 to 11. These dependencies, along with the form of the profile, indicate that the asymptotic limit is not achieved for sigma pi R-g(2) less than or equal to 11 in theta solvent conditions. The upper limit of surface density is limited by the interaction of the submerged blocks, which leads to a sharp rise in surface pressure (Pi). The increase of Pi with sigma far exceeds theoretical predictions, even in the asymptotic limit, and is attributed to distortion of chain configurations arising from limited lateral interpenetration. Anchoring energies compare well with differential chain energies at the desorption transition when the surface PDMS blocks an noninteracting. Comparisons are made with results obtained previously in good solvent conditions. (C) 1998 American Institute of Physics. [S0021-9606(98)50110-9]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CENS, Lab Leon Brillouin, F-91191 Gif Sur Yvette, France. Natl Inst Stand & Technol, Ctr Nutr Res, Gaithersburg, MD 20899 USA. RP Kent, MS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Lujan Center, LANL/G-4896-2012 NR 52 TC 29 Z9 29 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 1 PY 1998 VL 108 IS 13 BP 5635 EP 5645 DI 10.1063/1.475952 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZD913 UT WOS:000072738000055 ER PT J AU Goswami, BN AF Goswami, BN TI Interannual variations of Indian summer monsoon in a GCM: External conditions versus internal feedbacks SO JOURNAL OF CLIMATE LA English DT Article ID GENERAL-CIRCULATION MODEL; EURASIAN SNOW COVER; SEA-SURFACE TEMPERATURES; OCEAN-ATMOSPHERE MODEL; BIENNIAL VARIABILITY; SOUTHERN OSCILLATION; TROPICAL PACIFIC; RAINFALL; ENSO; SIMULATION AB The potential predictability of the Indian summer monsoon due to slowly varying sea surface temperature (SST) forcing is examined. Factors responsible for limiting the predictability are also investigated. Three multiyear simulations with the R30 version of the Geophysical Fluid Dynamics Laboratory's climate model are carried out for this purpose, The mean monsoon simulated by this model is realistic including the mean summer precipitation over the Indian continent. The interannual variability of the large-scale component of the monsoon such as the "monsoon shear index" and its teleconnection with Pacific SST is well simulated by the model in a 15-yr integration with observed SST as boundary condition. On regional scales, the skill in simulating the interannual variability of precipitation over the Indian continent by the model is rather modest and its simultaneous correlation with eastern Pacific SST is negative but poor as observed. The poor predictability of precipitation over the Indian region in the model is related to the fact that contribution to the interannual variability over this region due to slow SST variations [El Nino-Southern Oscillation (ENSO) related] is comparable to those due to regional-scale fluctuations unrelated to ENSO SST. The physical mechanism through which ENSO SST tend to produce reduction in precipitation over the Indian continent is also elucidated. A measure of internal variability of the model summer monsoon is obtained from a 20-yr integration of the same model with fixed annual cycle SST as boundary conditions but with predicted soil moisture and snow cover. A comparison of summer monsoon indexes between this run and the observed SST run shows that the internal oscillations can account for a large fraction of the simulated monsoon variability. The regional-scale oscillations in the observed SST run seems to arise from these internal oscillations. It is discovered that most of the interannual internal variability is due to an internal quasi-biennial oscillation (QBO) of the model atmosphere. Such a QBO is also found in the author's third 18-yr simulation in which fixed annual cycle of SST as well as soil moisture and snow cover are prescribed. This shows that the model QBO is not due to land-surface-atmosphere interaction. It is proposed that the model QBO arises due to an interaction between nonlinear intraseasonal oscillations and the annual cycle. Spatial structure of the QBO and its role in limiting the predictability of the Indian summer monsoon is discussed. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Goswami, BN (reprint author), Indian Inst Sci, Ctr Atmospher Sci, Bangalore 560012, Karnataka, India. EM goswamy@cas.iisc.ernet.in NR 56 TC 137 Z9 144 U1 0 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1998 VL 11 IS 4 BP 501 EP 522 DI 10.1175/1520-0442(1998)011<0501:IVOISM>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZK575 UT WOS:000073338900001 ER PT J AU Shapiro, LJ Goldenberg, SB AF Shapiro, LJ Goldenberg, SB TI Atlantic sea surface temperatures and tropical cyclone formation SO JOURNAL OF CLIMATE LA English DT Article ID SINGULAR-VALUE DECOMPOSITION; WEST-AFRICAN RAINFALL; SAMPLING ERRORS; EL-NINO; HURRICANES; INTENSE; ASSOCIATION; VARIABILITY; PATTERNS; ROTATION AB It has long been accepted that interannual fluctuations in sea surface temperature (SST) in the Atlantic are associated with fluctuations in seasonal Atlantic basin tropical cyclone frequency. To isolate the physical mechanism responsible for this relationship. a singular value decomposition (SVD) is used to establish the dominant covarying modes of tropospheric wind shear and SST as well as horizontal SST gradients. The dominant SVD mode of covarying vertical shear and SST gradients, which comprises equatorially confined near-zonal vertical wind shear fluctuations across the Atlantic basin, is highly correlated with both equatorial eastern Pacific SST anomalies (associated with El Nino) and West African Sahel rainfall. While this mode is strongly related to tropical storm, hurricanes, and major hurricane frequency in the Atlantic, it is not associated with any appreciable Atlantic SST signal. By contrast, the second SVD mode of covarying vertical shear and horizontal SST gradient variability, which is effectively uncorrelated with the dominant mode, is associated with SST fluctuations concentrated in the main tropical cyclone development region between 10 degrees and 20 degrees N. This mode is significantly correlated with tropical storm and hurricane frequency but not with major hurricane frequency. Statistical tests confirm the robustness of the mode, and lag correlations and physical reasoning demonstrate that the SST anomalies are not due to the developing tropical cyclones themselves. Anomalies of SST and vertical shear during years where the mode has substantial amplitude confirm the resemblance of the individual fields to the modal structure, as well as the association of hurricane development with the warmer SSTs. Although SSTs are of secondary importance to vertical shear in modulating hurricane formation, explaining only similar to 10% of the interannual variability in hurricane frequency over the similar to 50% explained by vertical shear, the results support the conclusion that warmer SSTs directly enhance development. The lack of correlation with major hurricanes implies that the underlying SSTs are not a significant factor in the development of these stronger systems. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP Shapiro, LJ (reprint author), Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. EM shapiro@chandra.atmos.colostate.edu RI Goldenberg, Stanley/C-5965-2014 OI Goldenberg, Stanley/0000-0001-6730-5819 NR 32 TC 93 Z9 94 U1 1 U2 12 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD APR PY 1998 VL 11 IS 4 BP 578 EP 590 DI 10.1175/1520-0442(1998)011<0578:ASSTAT>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZK575 UT WOS:000073338900006 ER PT J AU Peskin, AP Hardin, GR AF Peskin, AP Hardin, GR TI Gallium arsenide growth in a pancake MOCVD reactor SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE MOCVD; GaAs; GaC; finite element; MOVPE; metalorganic; epitaxy ID CHEMICAL VAPOR-DEPOSITION; BUOYANCY-DRIVEN INSTABILITY; VERTICAL CYLINDER; BINARY FLUIDS; HEAT-TRANSFER; GAS-PHASE; MODEL; FLOW AB We present a modeling study of the growth of gallium arsenide layers deposited onto a high-temperature susceptor in a pancake metalorganic chemical vapor deposition reactor. We analyzed the deposition process with a two-dimensional model that is axisymmetric about the vertical axis. The model includes detailed fluid flow, heat-and mass-transfer, and gas-phase and surface chemistry. The chemistry includes reactions to model the incorporation of carbon into the semiconductor as GaC. The mass transfer includes thermal diffusion for tri-, di- and mono-methyl gallium, as well as for three corresponding Ga-carbene species that are the precursors of GaC formation. The inclusion of a detailed reaction mechanism resulted in a very wide range of timescales, creating a challenging numerical problem. We found that the rate of gallium arsenide deposition and its uniformity over the susceptor depend strongly on the temperature of the susceptor, and are relatively insensitive to the rate of rotation of the susceptor up to 200 rpm, the maximum rotation-rate studied. Nonetheless, the dependence of the radial distribution of GaAs growth on the rate of susceptor rotation is notable in that it appears possible to determine an optimum rotation rate for this reactor. The flow state in the reactor is dominated by buoyancy up to a rotation rate of about 100 rpm. The buoyancy-driven recirculation above the susceptor could pose problems as an unwanted storage mechanism for reactants, which could hinder the ability to generate sharp interfaces between successive layers. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div 838, Boulder, CO 80303 USA. RP Hardin, GR (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div 838, 325 Broadway, Boulder, CO 80303 USA. EM hardin@boulder.nist.gov NR 18 TC 11 Z9 11 U1 0 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 APR PY 1998 VL 186 IS 4 BP 494 EP 510 DI 10.1016/S0022-0248(97)00821-X PG 17 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA ZE982 UT WOS:000072851000004 ER PT J AU Mueller, HJ AF Mueller, HJ TI Untitled SO JOURNAL OF DENTAL RESEARCH LA English DT Letter C1 NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. RP Mueller, HJ (reprint author), NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Bldg 224, Gaithersburg, MD 20899 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD APR PY 1998 VL 77 IS 4 BP 532 EP 533 PG 2 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA ZE543 UT WOS:000072803900001 PM 9539453 ER PT J AU Peterson, IM Pajares, A Lawn, BR Thompson, VP Rekow, ED AF Peterson, IM Pajares, A Lawn, BR Thompson, VP Rekow, ED TI Mechanical characterization of dental ceramics by hertzian contacts SO JOURNAL OF DENTAL RESEARCH LA English DT Article DE ceramics; Hertzian contact; quasi-plasticity; strength ID PARTIALLY-STABILIZED ZIRCONIA; HETEROGENEOUS GRAIN-STRUCTURE; FATIGUE-CRACK-PROPAGATION; CYCLIC FATIGUE; SILICON-CARBIDE; GLASS-CERAMICS; POLYCRYSTALLINE CERAMICS; INDENTATION RESPONSE; STRENGTH DEGRADATION; DAMAGE ACCUMULATION AB Hertzian indentation testing is proposed as a protocol for evaluating the role of microstructure in the mechanical response of dental ceramics. A major advantage of Hertzian indentation over more traditional fracture-testing methodologies is that it emulates the loading conditions experienced by dental restorations: Clinical variables (masticatory force and cuspal curvature) identify closely with Hertzian variables (contact load and sphere radius). In this paper, Hertzian responses on four generic dental ceramics systems-micaceous glass-ceramics, glass-infiltrated alumina, feldspathic porcelain, and transformable zirconia-are presented as case studies. Ceramographic sectioning by means of a "bonded-interface" technique provides new information on the contact damage modes. Two distinct modes are observed: "brittle" mode, classic macroscopic fracture outside the contact (ring, or cone cracks), driven by tensile stresses; and "quasi-plastic" mode, a relatively new kind of deformation below the contact (diffuse microdamage), driven by shear stresses. A progressive transition from the first to the second mode with increasing microstructural heterogeneity is observed. The degree of quasi-plasticity is readily apparent as deviations from ideal linear elastic responses on indentation stress-strain curves. Plots of threshold loads for the initiation of both fracture and deformation modes as a function of indenter radius constitute "damage maps" for the evaluation of prospective restoration damage under typical masticatory conditions. The degree of damage in both modes evolves progressively with load above the thresholds. Strength tests on indented specimens quantify sustainable stress levels on restoration materials after damage. The most brittle responses are observed in the fine glass-ceramics and porcelain; conversely, the most quasi-plastic responses are observed in the coarse glass-ceramics and zirconia; the medium glass-ceramics and alumina exhibit intermediate responses. Implications of the results in relation to future materials characterization, selection, and design are considered in the clinical context. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Med & Dent New Jersey, Sch Dent, Newark, NJ 07103 USA. RP Peterson, IM (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Pajares, Antonia/I-3881-2015; OI Pajares, Antonia/0000-0002-1086-7586; Thompson, Van P/0000-0003-0033-0344 FU NIDCR NIH HHS [P01 DE10976] NR 75 TC 150 Z9 155 U1 1 U2 23 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0022-0345 EI 1544-0591 J9 J DENT RES JI J. Dent. Res. PD APR PY 1998 VL 77 IS 4 BP 589 EP 602 PG 14 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA ZE543 UT WOS:000072803900012 PM 9539462 ER PT J AU Sogard, SM Olla, BL AF Sogard, SM Olla, BL TI Behavior of juvenile sablefish, Anoplopoma fimbria (Pallas), in a thermal gradient: Balancing food and temperature requirements SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE diel patterns; vertical distribution; stratification; ontogenetic changes; trade-offs ID CALIFORNIA CURRENT; PREDATION; LARVAL; GROWTH; HUNGER; OREGON; RISK AB The vertical distribution of early juvenile sablefish, Anoplopoma fimbria (Pallas), and their behavioral responses to changing food and temperature conditions were examined in laboratory experiments. Although field collections have suggested that juveniles are obligate residents of the neuston, laboratory experiments on diel movements indicated the potential for downward movement during the day, when activity levels were high and active foraging would be likely. The relationship of downward movement to fish size (small vs. large juveniles), prior feeding success (high vs. low rations) and thermal structure of the water column (isothermal vs. varying intensities of thermal stratification) were tested. Thermal stratification inhibited downward movement, with sablefish displaying clear avoidance of cold water even when the thermal gradient was moderate (12 degrees C top layer and 8 degrees C bottom layer). However, sablefish could be induced to swim downward into cold water if food was introduced beneath the thermocline. Across all temperature treatments, occurrence in cold water significantly increased when food was present. Increasing the sharpness of the thermal gradient (top layer = 12 degrees C, bottom layer = 8, 6, 4 or 2 degrees C) did not affect the percentage of time spent in cold water, but did shorten the maximum time an individual would spend beneath the thermocline. Movement into cold water constituted a potentially lethal risk for juvenile sablefish; dives beneath the thermocline that exceeded 60 s resulted in loss of equilibrium and immediate death for small fish moving from 12 to 2 degrees C water. Thus, sablefish displayed behavioral trade-offs between food acquisition and the physiological risk of cold temperatures, similar to previous studies documenting balancing of foraging behavior and predation risk. Behavioral responses to thermal stratification were modified by fish size and hunger level, with larger juveniles and those held on low rations spending more time in cold water. These behavioral responses correspond with the high feeding requirements necessary to maintain the naturally rapid growth rates of this species and the transitions in habitat associated with different life history stages. (C) 1998 Elsevier Science B.V. C1 Oregon State Univ, Hatfield Marine Sci Ctr, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Newport, OR 97365 USA. RP Sogard, SM (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Newport, OR 97365 USA. NR 25 TC 23 Z9 23 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD APR 1 PY 1998 VL 222 IS 1-2 BP 43 EP 58 DI 10.1016/S0022-0981(97)00137-8 PG 16 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA ZC792 UT WOS:000072618500004 ER PT J AU Kozyra, JU Fok, MC Sanchez, ER Evans, DS Hamilton, DC Nagy, AF AF Kozyra, JU Fok, MC Sanchez, ER Evans, DS Hamilton, DC Nagy, AF TI The role of precipitation losses in producing the rapid early recovery phase of the Great Magnetic Storm of February 1986 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RING CURRENT; GEOMAGNETIC STORM; EQUATORIAL MAGNETOSPHERE; LARGE-SCALE; FIELD; PROTON; MODEL; PLASMASPHERE; PLASMAPAUSE; MIDLATITUDE AB The possible role of precipitation losses in eroding stormtime ring current is subject to debate. To explore this controversy, the recovery phase of the February 6-10, 1986, great magnetic storm is examined, when intense ion precipitation was observed at midlatitudes by NOAA-6 and DMSP satellites, This storm period is particularly interesting because the ring current exhibits distinctive two-phase decay as seen in the Dst index, the early rapid timescale decay corresponding to the intense ion precipitation period described above, Hamilton et al. [1988] concluded, from close agreement between the observed timescale for ring current decay and the theoretical timescale for O+ charge exchange loss, that rapid early recovery phase of this storm resulted from the charge exchange loss of high energy O+; the second and longer decay phase was equated with H+ charge exchange loss. A model of the ring cut-rent evolution during this great magnetic storm [Fok et al., 1995] failed to reproduce the observed ring current decay rates, a puzzling result because charge exchange losses were well represented in the ring current model and initial and boundary conditions were taken from the same data set used in the Hamilton et al. [1988] study. A simple energy balance calculation for the global ring current is carried out using (1) either an energy input predicted from upstream solar wind parameters or one calculated from the drift-loss model output, (2) collisional loss timescales extracted from the drift-loss model, and (3) precipitation losses estimated from NOAA-6 and DMSP observations. The energy balance model replicates the evolution of the ring current energy content derived from Active Magnetospheric Particle Tracer Explorers/Charge Composition Explorer (AMPTE/CCE) observations when ion precipitation losses are included and model energy input function is reduced to agree with predictions based upon upstream solar wind parameters. The Of charge exchange losses and observed global precipitation losses were of equal magnitude in early recovery of the ring current during this great magnetic storm. Later longer decay timescales in the model resulted from a combination of O+ and H+ charge exchange losses; O+ charge exchange losses remained important throughout the model time interval. The present model produces agreement with the AMPTE/CCE estimates of ring current kinetic energy content versus time. Disagreement between the Dst* inferred from the AMPTE/CCE particle measurements and the observed Dst* is an interesting issue needing further explanation. C1 Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. NOAA, Space Environm Lab, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. SRI Int, Menlo Park, CA 94025 USA. RP Kozyra, JU (reprint author), Univ Michigan, Space Phys Res Lab, 2455 Hayward St, Ann Arbor, MI 48109 USA. RI Fok, Mei-Ching/D-1626-2012; OI Hamilton, Douglas/0000-0001-6103-8019 NR 42 TC 66 Z9 65 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD APR 1 PY 1998 VL 103 IS A4 BP 6801 EP 6814 DI 10.1029/97JA03330 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZF972 UT WOS:000072951700028 ER PT J AU Williams, PA Wang, CM AF Williams, PA Wang, CM TI Corrections to fixed analyzer measurements of polarization mode dispersion SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article DE fixed analyzer; k factor; mode coupling; peak counting; PMD; polarization mode dispersion; sampling density; wavelength scanning AB We report computer simulation results of polarization mode dispersion (PMD) measurements rising the fixed analyzer technique, We find a new value for the polarization mode coupling factor of 0.805 (a 2% difference with the old value of 0.824). Systematic biases due to sampling density and extrema thresholding are quantified (6-12% for typical measurement conditions), and a simple correction algorithm is presented which removes the effects of these biases within +/- 1.7%. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Williams, PA (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 5 TC 15 Z9 15 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 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD APR PY 1998 VL 16 IS 4 BP 534 EP 541 DI 10.1109/50.664060 PG 8 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA ZF351 UT WOS:000072888800008 ER PT J AU Raghavan, D Huynh, H Ferraris, CF AF Raghavan, D Huynh, H Ferraris, CF TI Workability, mechanical properties, and chemical stability of a recycled tyre rubber-filled cementitious composite SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID CONCRETE AB The workability and mechanical properties of mortar containing shredded automobile and truck tyres were evaluated. Two different shapes of rubber particles were used as constituents of mortar: (1) granules about 2 mm in diameter, and (2) shreds having two sizes which were, nominally, 5.5 mm x 1.2 mm and 10.8 mm x 1.8 mm (length x diameter). As expected, the geometry of the rubber particles influenced the fracture behaviour of rubber-containing mortar. The addition of rubber led to a decrease in flexural strength and plastic shrinkage cracking of mortar. The crack width and crack length due to plastic shrinkage were reduced for mortar containing the 10.8 x 1.8 mm rubber shreds compared with a mortar without shreds. The rheological properties of the mortar containing rubber shreds were comparable to those of a mortar without rubber and yielded lower plastic viscosity than a mortar containing 25.4 mm x 15 mu m (length x diameter) polypropylene fibres. The alkaline stability of rubber in mortar was also evaluated by immersing rubber shreds in NaOH and Ca(OH)(2) solutions for 4 mon and the results showed that there is less than 20% change in stress and strain value. The findings of the research suggest that automobile and truck tyres can be recycled by shredding and incorporating them into mortar and probably concrete for certain infrastructural applications. (C) 1998 Chapman & Hall. C1 Howard Univ, Dept Chem, Polymer Sci Div, Washington, DC 20059 USA. Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Raghavan, D (reprint author), Howard Univ, Dept Chem, Polymer Sci Div, Washington, DC 20059 USA. NR 26 TC 80 Z9 103 U1 1 U2 12 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD APR 1 PY 1998 VL 33 IS 7 BP 1745 EP 1752 DI 10.1023/A:1004372414475 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA ZD535 UT WOS:000072695900008 ER PT J AU Odashima, H Tachikawa, M Zink, LR Evenson, KM AF Odashima, H Tachikawa, M Zink, LR Evenson, KM TI Sub-doppler frequency measurements of (NH3)-N-15 laser transitions SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID FAR-INFRARED SPECTROSCOPY; CONSTANTS; STANDARDS; CO2-LASER; BAND; CO2; GAS C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. Toyama Univ, Dept Phys, Toyama 930, Japan. Meiji Univ, Dept Phys, Kawasaki, Kanagawa 214, Japan. RP Odashima, H (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, 325 Broadway, Boulder, CO 80303 USA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD APR PY 1998 VL 188 IS 2 BP 245 EP 247 DI 10.1006/jmsp.1997.7353 PG 3 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA ZJ957 UT WOS:000073270700014 ER PT J AU Merzbacher, CI Barker, JG Swider, KE Ryan, JV Bernstein, RA Rolison, DR AF Merzbacher, CI Barker, JG Swider, KE Ryan, JV Bernstein, RA Rolison, DR TI Characterization of multi-phase aerogels by contrast-marching SANS SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 5th International Symposium on Aerogels CY SEP 08-10, 1997 CL MONTPELLIER, FRANCE SP Univ Montpellier, CNRS, Reg Languedoc Roussillon, Ctr Etud Commissariat Energie Atom Bruyeres Chatel, Ctr Etud Commissariat Energie Atom Vahrho DE small-angle neutron scattering (SANS); aerogel; oxidation; contrast matching ID ANGLE NEUTRON-SCATTERING; SILICA AEROGEL AB Contrast-matching small-angle neutron scattering (SANS) has been used to independently characterize the structures of two-phase aerogels consisting of a metal oxide supported on silica aerogel. Ru oxide was formed on silica aerogel by oxidation at 400 degrees C of ruthenocene, impregnated from the vapor phase, or Ru(III)acetylacetonate, impregnated via an acetone solution. Fe oxide was formed by vapor-phase impregnation of ferrocene, followed by reduction at 400 degrees C and exposure to ambient air. The Ru oxide forms particles several tens of nanometers in diameter in the aerogel mesopores. The Fe oxide forms a coating which mimics the structure of the support. The silica aerogel structure is not affected by the deposition and heat treatment processes. (C) 1998 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Merzbacher, CI (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. EM merzbacher@nrl.navy.mil NR 16 TC 9 Z9 9 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD APR PY 1998 VL 225 IS 1-3 BP 234 EP 238 DI 10.1016/S0022-3093(98)00044-1 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZY627 UT WOS:000074642600046 ER PT J AU Heckert, NA Simiu, E Whalen, T AF Heckert, NA Simiu, E Whalen, T TI Estimates of hurricane wind speeds by "peaks over threshold" method SO JOURNAL OF STRUCTURAL ENGINEERING-ASCE LA English DT Article AB We report results that lend support to the hypothesis that extreme hurricane wind speeds are described predominantly by reverse Weibull distributions, which have limited upper tails. This is consistent with the result reported recently in the atmospheric sciences literature that, on physical grounds, hurricanes have finite maximum intensity. The sampling errors typical of our results are controlled by the relatively short length of the historical record (about one hundred years, i.e., a few tens of hurricane events for any one location) and are, in practice, independent of whether the size of the simulated data samples for any specified location is of the order of 1,000 or larger. According to our estimates, mean recurrence intervals of wind speeds corresponding to nominal ultimate wind loads specified in the ASCE standard 7-95 for extratropical storm regions on the one hand, and hurricane-prone regions on the other, are mutually inconsistent with respect to risk. C1 NIST, Computat & Appl Math Lab, Gaithersburg, MD 20899 USA. NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Heckert, NA (reprint author), NIST, Computat & Appl Math Lab, Gaithersburg, MD 20899 USA. NR 18 TC 31 Z9 36 U1 1 U2 3 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9445 J9 J STRUCT ENG-ASCE JI J. Struct. Eng.-ASCE PD APR PY 1998 VL 124 IS 4 BP 445 EP 449 DI 10.1061/(ASCE)0733-9445(1998)124:4(445) PG 5 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA ZD403 UT WOS:000072681700012 ER PT J AU Lee, SK Lawn, BR AF Lee, SK Lawn, BR TI Role of microstructure in Hertzian contact damage in silicon nitride: II, strength degradation SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID R-CURVE BEHAVIOR; FATIGUE; CERAMICS; FRACTURE AB In this Part II of a two-part study of the role of microstructure on Hertzian contact damage in silicon nitride we determine strength degradation properties. As previously, three microstructures are investigated: fine (F), medium (M) and coarse (C), representing a progressive transition from brittle to quasi-plastic damage. In both the F and M materials, failures originate from cone cracks (although limited quasi-plasticity is evident in the latter material). These: two materials show abrupt losses in strength at the critical contact loads for cone crack initiation, and steady falloff thereafter at higher contact loads. In the C material, failures occur from critical shear faults within the damage "yield" zones. The strengths in this material fall off much more gradually, without abrupt drop, above about twice the critical load for the onset of yield. Fracture mechanics models for each type of failure mode provide explicit relations for the degraded strength as a function of contact load. These models account for all the essential features in the observed strength degradation data. Particular attention Is given to indenter size effects in the strength responses. Sphere radius has a profound influence on the critical loads for the onset of degradation, but relatively little influence on the degraded strengths at higher loads. Implications of the results concerning contact fatigue and wear are briefly considered. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 29 TC 26 Z9 27 U1 1 U2 3 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 APR PY 1998 VL 81 IS 4 BP 997 EP 1003 PG 7 WC Materials Science, Ceramics SC Materials Science GA ZJ248 UT WOS:000073195000023 ER PT J AU Ledbetter, H Kim, S Balzar, D AF Ledbetter, H Kim, S Balzar, D TI Elastic properties of mullite SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB Using ultrasonic methods, we determined the ambient-temperature elastic constants of dense (99.7%) hot-pressed polycrystalline 3:2 mullite (3A1(2)O(3) . 2SiO(2)). We report the usual polycrystal elastic constants: Young's, shear, and bulk moduli, and the Poisson's ratio (nu). The Poisson's ratio (nu = 0.280) suggests interatomic bonding that is very different from that of either alumina or silica, Temperature dependences of the elastic constants show a strong irregularity; for example, nu decreases as the temperature increases. This irregularity suggests an internal-state change that hs perhaps related to the incommensurate structural modulation. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. RP Ledbetter, H (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 15 TC 42 Z9 42 U1 1 U2 6 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD APR PY 1998 VL 81 IS 4 BP 1025 EP 1028 PG 4 WC Materials Science, Ceramics SC Materials Science GA ZJ248 UT WOS:000073195000027 ER PT J AU Ali, MA Kim, YK Hwang, W Rudd, ME AF Ali, MA Kim, YK Hwang, W Rudd, ME TI Electron-impact total ionization cross sections of environmentally sensitive molecules SO JOURNAL OF THE KOREAN PHYSICAL SOCIETY LA English DT Article; Proceedings Paper CT 3rd International Seminar on Atomic and Molecular Physics CY OCT 07-10, 1996 CL POHANG, SOUTH KOREA ID THRESHOLD; SO2; MODEL; MASS; CS2 AB A new theoretical model was used to calculate electron-impact total ionization cross sections of environmentally sensitive molecules: COS, CS2, H2S, NO2, N2O, O-3, S-2, and SO2. The theory is a combination of the Mott cross section and the dipole contribution based on Bethe's theory. Our theory does not contain any adjustable parameters, and uses simple numerical data from the ground state molecular wave function of the target molecule. There is only one experimental data set for ozone that covers a wide range of incident energies, and since it is relative data we normalized it to our cross sections at the peak. This resulted in excellent agreement between theory and experiment. We are also in good agreement with the available measurements on N2O. Our theory agrees with some experimental data on SO2, but not with others. C1 Howard Univ, Dept Chem, Washington, DC 20059 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA. RP Ali, MA (reprint author), Howard Univ, Dept Chem, Washington, DC 20059 USA. NR 24 TC 2 Z9 2 U1 0 U2 4 PU KOREAN PHYSICAL SOC PI SEOUL PA 635-4, YUKSAM-DONG, KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 0374-4884 J9 J KOREAN PHYS SOC JI J. Korean Phys. Soc. PD APR PY 1998 VL 32 IS 4 BP 499 EP 504 PG 6 WC Physics, Multidisciplinary SC Physics GA ZJ223 UT WOS:000073191800013 ER PT J AU Simiu, E Heckert, NA AF Simiu, E Heckert, NA TI Wind direction and hurricane-induced ultimate wind loads SO JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS LA English DT Article; Proceedings Paper CT 2nd European and African Conference on Wind Engineering CY JUN 22-26, 1997 CL GENOA, ITALY SP Univ Genova, Dept Struct & Geotech Engn, Int Assoc Wind Engn, Italian Natl Assoc Wind Engn, Liguria Reg, Province Genova, Municipal Genova, UNESCO AB A consensus on the wind directionality issue is needed for the validation by building officials of the wind-tunnel procedure allowed by the ASCE 7-95 Standard, and for the development of provisions for wind loads that use large aerodynamic and climatological databases. As a contribution to the debate needed to achieve such a consensus, we describe an updated method for estimating wind loads that takes into account the directional dependence of the aerodynamic coefficients and the extreme wind climate, and uses the 'peaks over threshold' approach for the estimation of extremes. For hurricane-prone regions, assuming epistemic uncertainties are negligible, we estimate mean recurrence intervals (MRIs) of wind loads inducing the design strength, obtained from 50 yr loads via multiplication by a factor specified by the ASCE 7-95 Standard. For typical aerodynamic coefficients with strong directional preference, depending upon location and building orientation those estimated MRIs varied between less than 1000 to more than 10 000 yr. If epistemic uncertainties were taken into account the estimated MRIs would be shorter. We also found that for loads with very large MRIs the common practice of disregarding direction effects is not necessarily conservative from a structural engineering viewpoint. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP Simiu, E (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 9 TC 1 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6105 J9 J WIND ENG IND AEROD JI J. Wind Eng. Ind. Aerodyn. PD APR-AUG PY 1998 VL 74-6 BP 1037 EP 1046 DI 10.1016/S0167-6105(98)00095-6 PG 10 WC Engineering, Civil; Mechanics SC Engineering; Mechanics GA 110LR UT WOS:000075383400093 ER PT J AU Dawson, S Barlow, J Ljungblad, D AF Dawson, S Barlow, J Ljungblad, D TI Sounds recorded from Baird's beaked whale, Berardius bairdii SO MARINE MAMMAL SCIENCE LA English DT Article C1 Univ Otago, Dept Marine Sci, Dunedin, New Zealand. Natl Marine Fisheries Serv, SW Fisheries Ctr, La Jolla, CA 92038 USA. Ljungblad Associates, Elk Mt, WY 82324 USA. RP Dawson, S (reprint author), Univ Otago, Dept Marine Sci, POB 56, Dunedin, New Zealand. OI Dawson, Stephen/0000-0003-3182-0186 NR 8 TC 27 Z9 31 U1 1 U2 8 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 1998 VL 14 IS 2 BP 335 EP 344 DI 10.1111/j.1748-7692.1998.tb00724.x PG 10 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA ZG014 UT WOS:000072956100014 ER PT J AU Goddard, PD Rugh, DJ AF Goddard, PD Rugh, DJ TI A group of right whales seen in the Bering Sea in July 1996 SO MARINE MAMMAL SCIENCE LA English DT Article ID EUBALAENA-GLACIALIS C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Goddard, PD (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 25 TC 13 Z9 14 U1 0 U2 1 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 1998 VL 14 IS 2 BP 344 EP 349 DI 10.1111/j.1748-7692.1998.tb00725.x PG 6 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA ZG014 UT WOS:000072956100015 ER PT J AU Johnson, SW Rice, SD Moles, DA AF Johnson, SW Rice, SD Moles, DA TI Effects of submarine mine tailings disposal on juvenile yellowfin sole (Pleuronectes asper): A laboratory study SO MARINE POLLUTION BULLETIN LA English DT Article DE yellowfin sole; Pleuronectes asper; Alaska; mine tailings ID BODY-SIZE; SEDIMENTS; PREDATION; GROWTH; IMPACT; OIL AB Behaviour, survival, and growth studies were conducted in the laboratory on juvenile yellowfin sole (Pleuronectes asper) exposed to mine tailings produced by a pilot plant for a gold mine near Juneau, Alaska. Fish avoided fresh tailings in favour of natural marine sediment (control) and weathered tailings (75 years old). Only when fresh tailings were covered with 2 cm of control sediment did fish prefer control and fresh tailings equally Survival of fish was similar (p = 0.66) for fish held on all test sediments. Fish held on fresh tailings for 60 d grew significantly (p = 0.013) less than control fish during the first, but not the second, month. Avoidance or short-term reductions in flatfish growth may occur from submarine disposal of tailings. Rapid burial of tailings in areas with high natural sedimentation (e.g., large river mouths) may accelerate recovery of the sea floor. Published by Elsevier Science Ltd. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. RP Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 31 TC 11 Z9 11 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD APR PY 1998 VL 36 IS 4 BP 278 EP 287 DI 10.1016/S0025-326X(97)00181-1 PG 10 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA ZU636 UT WOS:000074217900013 ER PT J AU Tepper, T Shechtman, D van Eleerden, D Josell, D AF Tepper, T Shechtman, D van Eleerden, D Josell, D TI Allotropic phase formation in Ti/Zr multilayers SO MATERIALS LETTERS LA English DT Article DE multilayer; thin film; titanium; zirconium; composites; allotropic phases ID FCC TITANIUM; HYDRIDE FORMATION; ZIRCONIUM AB The presence of face centered cubic Ti and Zr in Zr/Ti multilayers in specimens prepared for transmission electron microscopy is noted. X-ray diffraction shows that in the as-deposited state the multilayers contain the equilibrium hcp Ti and Zr phases. implying that a transformation occurs during thinning of specimens for TEM study. (C) 1998 Elsevier Science B.V. C1 Technion Israel Inst Technol, Dept Mat Engn, IL-32000 Haifa, Israel. NIST, Gaithersburg, MD 20899 USA. RP Shechtman, D (reprint author), Technion Israel Inst Technol, Dept Mat Engn, IL-32000 Haifa, Israel. NR 14 TC 9 Z9 9 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD APR PY 1998 VL 35 IS 1-2 BP 100 EP 107 DI 10.1016/S0167-577X(97)00231-0 PG 8 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA ZK443 UT WOS:000073321400018 ER PT J AU Cava, RJ Krajewski, JJ Roth, RS AF Cava, RJ Krajewski, JJ Roth, RS TI Low temperature coefficient bulk dielectrics in the Ca2Nb2O7-Ca2Ta2O7 system SO MATERIALS RESEARCH BULLETIN LA English DT Article DE oxides; ceramics; dielectric properties ID CERAMICS AB The dielectric properties of bulk polycrystalline ceramics in the binary Ca2Ta2O7-Ca2Nb2O7 system are reported. Measurements of the dielectric constant at 1 MHz were made at temperatures between 0 and 100 degrees C. The large negative (for the niobate) and positive (for the tantalate) temperature coefficients for the dielectric constants in the pure materials in the vicinity of room temperature can be balanced in a two-phase region near x = 0.36 in Ca2Ta2-xNbxO7. At this composition, the dielectric constant is approximately 30, and the temperature coefficient of the dielectric constant is approximately 2 ppm/degrees C. The Q in our unoptimized polycrystalline ceramic at 1 MHz is approximately 5000. (C) 1998 Elsevier Science Ltd. C1 AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Cava, RJ (reprint author), Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. NR 6 TC 38 Z9 38 U1 3 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-5408 J9 MATER RES BULL JI Mater. Res. Bull. PD APR PY 1998 VL 33 IS 4 BP 527 EP 532 DI 10.1016/S0025-5408(98)00002-6 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA ZH759 UT WOS:000073144800001 ER PT J AU Read, DT AF Read, DT TI Young's modulus of thin films by speckle interferometry SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article ID MOIRE INTERFEROMETRY; MECHANICAL-PROPERTIES; LOCAL DEFORMATION; STRAIN; COMPOSITES; FATIGUE AB Speckle interferometry has been applied to the measurement of Young's modulus in thin films. The present study has two novel aspects: the specimens used were approximately 1 mu m thick and less than 1 mm long, so the speckle images were obtained by photomicroscopy; and the digital images were analysed by quantitative treatment at intense speckles, rather than by the more standard techniques. Displacements and strains within the gauge length were obtained with low statistical uncertainties. Young's modulus values for three varieties of copper thin films were obtained. All were lower than the polycrystalline bulk average value and the electrodeposited film's modulus was lower than those of both the vapour-deposited films. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. NR 35 TC 58 Z9 63 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD APR PY 1998 VL 9 IS 4 BP 676 EP 685 DI 10.1088/0957-0233/9/4/016 PG 10 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZJ170 UT WOS:000073186500016 ER PT J AU Behringer, DW Ji, M Leetmaa, A AF Behringer, DW Ji, M Leetmaa, A TI An improved coupled model for ENSO prediction and implications for ocean initialization. Part I: The Ocean Data Assimilation System SO MONTHLY WEATHER REVIEW LA English DT Article ID NINO SOUTHERN OSCILLATION; EL-NINO; PREDICTABILITY AB An improved forecast system has been developed for El Nino-Southern Oscillation (ENSO) prediction at the National Centers for Environmental Prediction. Improvements have been made both to the ocean data assimilation system and to the coupled ocean-atmosphere forecast model. In Part I of a two-part paper the authors describe the new assimilation system. The important changes are 1) the incorporation of vertical variation in the first-guess error variance that concentrates temperature corrections in the thermocline and 2) the overall reduction in the magnitude of the estimated first-guess error. The new system was used to produce a set of retrospective ocean analyses for 1980-95. The new analyses are less noisy than their earlier counterparts and compare more favorably with independent measurements of temperature, currents, and sea surface height variability. Part II of this work presents the results of using these analyses to initialize the coupled forecast model for ENSO prediction. C1 NOAA, Natl Weather Serv, Natl Ctr Environm Predict, Washington, DC 20233 USA. RP Ji, M (reprint author), Natl Ctr Enviromn Predict, Climate Modeling Branch, 5200 Auth Rd,Rm 807, Camp Springs, MD 20746 USA. NR 26 TC 213 Z9 237 U1 3 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD APR PY 1998 VL 126 IS 4 BP 1013 EP 1021 DI 10.1175/1520-0493(1998)126<1013:AICMFE>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF765 UT WOS:000072930900012 ER PT J AU Ji, M Behringer, DW Leetmaa, A AF Ji, M Behringer, DW Leetmaa, A TI An improved coupled model for ENSO prediction and implications for ocean initialization. Part II: The coupled model SO MONTHLY WEATHER REVIEW LA English DT Article ID NINO SOUTHERN OSCILLATION; EL-NINO; ATMOSPHERE MODEL; FORECAST SYSTEM; PACIFIC-OCEAN; PREDICTABILITY; THERMODYNAMICS; ASSIMILATION; CLIMATE AB An improved forecast system has been developed and implemented for ENSO prediction at the National Centers for Environmental Prediction (NCEP). This system consists of a new ocean data assimilation system and an improved coupled ocean-atmosphere forecast model (CMP12) for ENSO prediction. The new ocean data assimilation system is described in Part I of this two-part paper. The new coupled forecast model (CMP12) is a variation of the standard NCEP coupled model (CMP10). Major changes in the new coupled model are improved vertical mixing for the ocean model: relaxation of the model's surface salinity to the climatological annual cycle; and incorporation of an anomalous freshwater flux forcing. Also, the domain in which the oceanic SST couples to the atmosphere is limited to the tropical Pacific. Evaluation of ENSO prediction results show that the new coupled model, using the more accurate ocean initial conditions, achieves higher prediction skill. However, two sets of hindcasting experiments (one using the more accurate ocean initial conditions but the old coupled model, the other using the new coupled model but the less accurate ocean initial conditions), result in no improvement in prediction skill. These results indicate that future improvement in ENSO prediction skill requires systematically improving both the coupled model and the ocean analysis system. The authors' results also suggest that for the purpose of initializing the coupled model for ENSO prediction care should be taken to give sufficient weight to the model dynamics during the ocean data assimilation. This can reduce the danger of aliasing large-scale model biases into the low-Frequency variability in the ocean initial conditions, and also reduce the introduction of small-scale noise into the initial conditions caused by overfitting the model to sparse observations. C1 NOAA, Natl Weather Serv, Natl Ctr Environm Predict, Washington, DC 20233 USA. RP Ji, M (reprint author), Natl Ctr Environm Predict, Climate Modeling Branch, 5200 Auth Rd,Rm 807, Camp Springs, MD 20746 USA. NR 35 TC 75 Z9 77 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD APR PY 1998 VL 126 IS 4 BP 1022 EP 1034 DI 10.1175/1520-0493(1998)126<1022:AICMFE>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF765 UT WOS:000072930900013 ER PT J AU deReynier, YL AF deReynier, YL TI Evolving principles of international fisheries law and the North Pacific anadromous fish commission SO OCEAN DEVELOPMENT AND INTERNATIONAL LAW LA English DT Article DE anadromous; international fisheries management; law of the sea; North Pacific; Pacific salmon AB International fisheries law, now shaped by the 1982 Law of the Sea Convention has been subject to a philosophical evolution in the latter half of the twentieth century, from protecting freedoms of high seas fishing nations to supporting proprietary rights of coastal nations. This shift is illustrated by events in North Pacific international anadromous stocks management, which hate recently culminated in the restrictive Convention for the Conservation of Anadromous Stocks in the North Pacific Ocean, the founding instrument of the North Pacific Anadromous Fish Commission (NPAFC). Organizations like NPAFC will shape future international fisheries management for a world with growing human populations and growing potential for international conflicts over natural resources. The place of the NPAFC Convention in the law of the sea regime, the relationship between NPAFC and other international resource management bodies, and the flexibility that the organization maintains through its future management challenges will cycle into future international legal philosophy on cooperative marine resource management. C1 NOAA, Natl Marine Fisheries Serv, Seattle, WA 98115 USA. RP deReynier, YL (reprint author), NOAA, Natl Marine Fisheries Serv, 7600 Sand Point Way NE,BIN C15700,NW Reg, Seattle, WA 98115 USA. NR 48 TC 4 Z9 4 U1 0 U2 5 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0090-8320 J9 OCEAN DEV INT LAW JI Ocean Dev. Int. Law PD APR-JUN PY 1998 VL 29 IS 2 BP 147 EP 178 PG 32 WC International Relations; Law SC International Relations; Government & Law GA ZT212 UT WOS:000074060900003 ER PT J AU Paek, EG Wilson, CL Roberts, JW Watson, CI AF Paek, EG Wilson, CL Roberts, JW Watson, CI TI High-speed temporal characterization and visualization of spatial light modulators and flat-panel displays SO OPTICS LETTERS LA English DT Article ID LIQUID-CRYSTAL TELEVISION AB An apparatus that can characterize and visualize temporal dynamics of spatial light modulators (SLM's) and flat-panel displays is constructed and evaluated by use of a commercially available SLM. The apparatus is based on the stroboscopic video sampling method and has a temporal resolution of the order of microseconds, permitting measurement of a long event (>100 ms) with a high signal-to-noise ratio. Experimental results demonstrate the visualization of the temporal image sequencing and addressing in an SLM. C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP Paek, EG (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 5 TC 5 Z9 5 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 1 PY 1998 VL 23 IS 7 BP 546 EP 548 DI 10.1364/OL.23.000546 PG 3 WC Optics SC Optics GA ZF079 UT WOS:000072860500022 PM 18084572 ER PT J AU Cohen, H Solomon, V Alferiev, IS Breuer, E Ornoy, A Patlas, N Eidelman, N Hagele, G Golomb, G AF Cohen, H Solomon, V Alferiev, IS Breuer, E Ornoy, A Patlas, N Eidelman, N Hagele, G Golomb, G TI Bisphosphonates and tetracycline: Experimental models for their evaluation in calcium-related disorders SO PHARMACEUTICAL RESEARCH LA English DT Article DE bisphosphonates; tetracycline; calcification; hydroxyapatite; bone resorption; synthesis ID BONE-RESORPTION; CALCIFICATION; RATS; ACID; ALENDRONATE; INVITRO; INVIVO; BISACYLPHOSPHONATES; ANTICALCIFICATION; DIPHOSPHONATES AB Purpose. This work was aimed at synthesizing novel bisphosphonates (BPs) and examining them in comparison to clinically used BPs such as pamidronate and alendronate, and to tetracycline, in order to evaluate their potential as anticalcification and antiresorption agents. The correlation between the various models was examined in order to establish facile experimental models for pre-screening of potential compounds. Methods. Nitrogen-containing heterocyclic, novel BPs such as 2-(3-methylimidazolio) ethylidene-1,1-bisphosphonic acid betaine (VS-5b), 2-(2-dimethylamino-4-pyrazinio)ethylidene-1,1-bisphosphonic acid betaine (VS-6b), and 2-(2-alpha-pyridylethylthio) ethylidene-1,1-bisphosphonic acid (ISA-225), were synthesized and evaluated in comparison to clinically used BPs, in various experimental models of resorption and calcification. Results. The physicochemical properties of the novel compounds are slightly different than the BPs in clinical use: the pKa values are lower, the affinity for hydroxyapatite is lower and the solubilities of the calcium salts are higher. The anticalcification potencies of the novel compounds were high and ranked as follows: alendronate = pamidronate > VS-6b = VS-5b = ISA-225 > tetracycline. The in vivo antiresorption activity of VS-5b and VS-6b in comparison to that of the clinically employed, pamidronate, was shown to be similar and higher, respectively. Conclusions. The anticalcification activity of the novel compounds as well as that of tetracycline was lower than that of alendronate. The antiresorption activity of VS-6b was similar to that of pamidronate. A good correlation between the different models was found, enabling the facile screening of novel compounds. The activities of tetracycline and EDTA highlight the distinct behavior of BPs as "crystal poison." In addition, tetracycline was found to be a potent anticalcification agent in the ectopic calcification model. C1 Hebrew Univ Jerusalem, Sch Pharm, Fac Med, Dept Pharmaceut, IL-91120 Jerusalem, Israel. Hebrew Univ Jerusalem, Sch Pharm, Fac Med, Dept Pharmaceut Chem, IL-91120 Jerusalem, Israel. Hebrew Univ Jerusalem, Fac Med, Dept Anat, IL-91120 Jerusalem, Israel. NIST, Amer Dent Assoc Hlth Fdn, Paftenbarger Res Ctr, Gaithersburg, MD 20899 USA. Univ Dusseldorf, Inst Anorgan Chem & Strukt Chem, D-4000 Dusseldorf, Germany. RP Golomb, G (reprint author), Hebrew Univ Jerusalem, Sch Pharm, Fac Med, Dept Pharmaceut, POB 12065, IL-91120 Jerusalem, Israel. EM golomb@cc.huji.ac.il RI Breuer, Eli/E-8382-2011; OI Golomb, Gershon/0000-0002-7369-9831 FU NHLBI NIH HHS [HL30035] NR 42 TC 24 Z9 25 U1 0 U2 4 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0724-8741 J9 PHARMACEUT RES JI Pharm. Res. PD APR PY 1998 VL 15 IS 4 BP 606 EP 613 DI 10.1023/A:1011990129437 PG 8 WC Chemistry, Multidisciplinary; Pharmacology & Pharmacy SC Chemistry; Pharmacology & Pharmacy GA ZL090 UT WOS:000073397800019 PM 9587958 ER PT J AU Miyano, KE Arp, U Southworth, SH Meehan, TE Walsh, TR Larkins, FP AF Miyano, KE Arp, U Southworth, SH Meehan, TE Walsh, TR Larkins, FP TI Sulfur K beta x-ray emission from carbonyl sulfide: Variations with polarization and excitation energy at the S K threshold SO PHYSICAL REVIEW A LA English DT Article ID AB-INITIO CALCULATIONS; GAUSSIAN BASIS FUNCTIONS; FIRST-ROW ATOMS; MOLECULAR CALCULATIONS; N2O MOLECULE; SPECTRA; ANISOTROPY AB Sulfur K beta x-ray-emission spectra from carbonyl sulfide have been measured with resonant excitation at the sulfur K absorption threshold and compared with results of self-consistent field and singles-doubles configuration-interaction calculations. For excitation to the strong 4 pi absorption resonance, a splitting of the main emission peak is interpreted in terms of influence of the 4 pi electron on the final valence-hole states. The polarization selectivity of the emission spectrometer was used to distinguish emission polarized parallel versus perpendicular with respect to the polarization of the excitation radiation. The observed polarization dependence is consistent with the molecular symmetries of the calculated intermediate and final states. C1 CUNY Brooklyn Coll, Dept Phys, Brooklyn, NY 11210 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Melbourne, Sch Chem, Parkville, Vic 3052, Australia. RP Miyano, KE (reprint author), CUNY Brooklyn Coll, Dept Phys, Brooklyn, NY 11210 USA. RI Walsh, Tiffany/C-2667-2009; Arp, Uwe/C-2854-2009; OI Walsh, Tiffany/0000-0002-0233-9484; Arp, Uwe/0000-0002-6468-9455 NR 28 TC 6 Z9 6 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1998 VL 57 IS 4 BP 2430 EP 2435 DI 10.1103/PhysRevA.57.2430 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZJ698 UT WOS:000073243700026 ER PT J AU Brown, JM Zink, LR Evenson, KM AF Brown, JM Zink, LR Evenson, KM TI F-19(+) atom in its ground P-3 state: The J=0 <- 1 fine-structure interval SO PHYSICAL REVIEW A LA English DT Article ID LASER-MAGNETIC-RESONANCE; HYPERFINE-STRUCTURE; SPECTROSCOPY; CARBON; LINES AB The J=0<--1 fine-structure transition in the atomic ion F+ in its ground P-3 State has been detected in the laboratory by far-infrared laser magnetic resonance. The fine-structure interval has been measured accurately as 4 453 253.2+/-1.6 MHz (148.544 537+/-0.000 053 cm(-?(1)) which corresponds to a wavelength of 67.319 877 +/-0.000 015 mu m. The hyperfine splitting for the F-19 nucleus was also observed and its measured value is in fair agreement with predictions based on ab initio wave functions. C1 Phys & Theoret Chem Lab, Oxford OX1 3QZ, England. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Brown, JM (reprint author), Phys & Theoret Chem Lab, S Parks Rd, Oxford OX1 3QZ, England. NR 28 TC 10 Z9 10 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 1998 VL 57 IS 4 BP 2507 EP 2510 DI 10.1103/PhysRevA.57.2507 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZJ698 UT WOS:000073243700037 ER PT J AU Nikitenko, VI Gornakov, VS Dedukh, LM Kabanov, YP Khapikov, AF Shapiro, AJ Shull, RD Chaiken, A Michel, RP AF Nikitenko, VI Gornakov, VS Dedukh, LM Kabanov, YP Khapikov, AF Shapiro, AJ Shull, RD Chaiken, A Michel, RP TI Asymmetry of domain nucleation and enhanced coercivity in exchange-biased epitaxial NiO/NiFe bilayers SO PHYSICAL REVIEW B LA English DT Article ID GIANT MAGNETORESISTANCE; ANISOTROPY; FILMS; INTERFACES; LAYERS; MODEL; NIO AB Magnetization reversal processes in epitaxial NiO/NiFe bilayers were studied using the magneto-optic indicator film technique. The influence of dislocations on these processes was determined. Remagnetization parallel to the unidirectional anisotropy axis proceeds by domain nucleation and growth, with nucleation center activity being asymmetric with respect to the applied field sign. Magnetization reversal in the hard axis direction occurs by incoherent rotation. The enhanced coercivity and asymmetric nucleation can be explained by taking into account domain wall behavior in the antiferromagnetic layer. C1 Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow District, Russia. NIST, Div Met, Gaithersburg, MD 20899 USA. Univ Calif Lawrence Livermore Natl Lab, Div Mat Sci & Technol, Livermore, CA 94551 USA. RP Nikitenko, VI (reprint author), Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow District, Russia. RI Shull, Robert/F-5971-2013 NR 21 TC 80 Z9 80 U1 1 U2 9 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 1998 VL 57 IS 14 BP R8111 EP R8114 DI 10.1103/PhysRevB.57.R8111 PG 4 WC Physics, Condensed Matter SC Physics GA ZH083 UT WOS:000073070400014 ER PT J AU Norman, EB Browne, E Chan, YD Goldman, ID Larimer, RM Lesko, KT Nelson, M Wietfeldt, FE Zlimen, I AF Norman, EB Browne, E Chan, YD Goldman, ID Larimer, RM Lesko, KT Nelson, M Wietfeldt, FE Zlimen, I TI Half-life of Ti-44 SO PHYSICAL REVIEW C LA English DT Article ID BI-207; LIVES AB We present the results of two separate measurements of the half-life of Ti-44 relative to those of Na-22 and Bi-207, respectively. By comparing the numbers of 1157-keV gamma rays from Ti-44 to those of 1274-keV gamma rays from Na-22 observed from a mixed source over a period of approximately 2 yr, we determined the half-life of Ti-44 to be 61.5+/-1.0 yr. From an approximately 1-yr-long study of another mixed source, where we compared the numbers of 1157-keV gamma rays from Ti-44 to those of 1064-keV gamma rays from Bi-207, We determined the Ti-44 half-life to be 62+/-5 yr. From these two results, we have obtained a best value of 62+/-2 yr for the half-life of Ti-44. The astrophysical implications of this result are discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Sao Paulo, Inst Fis, BR-01498 Sao Paulo, Brazil. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Norman, EB (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 35 TC 37 Z9 37 U1 0 U2 5 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 APR PY 1998 VL 57 IS 4 BP 2010 EP 2016 DI 10.1103/PhysRevC.57.2010 PG 7 WC Physics, Nuclear SC Physics GA ZK406 UT WOS:000073317700053 ER PT J AU Leibfried, D Pfau, T Monroe, C AF Leibfried, D Pfau, T Monroe, C TI Shadows and mirrors: Reconstructing quantum states of atom motion SO PHYSICS TODAY LA English DT Article ID TRAPPED ATOM; TOMOGRAPHY AB Quantum mechanics allows us only one incomplete glimpse of a wavefunction, but if systems can be identically prepared over and over, quantum equivalents of shadows and mirrors can provide the full picture. C1 Univ Innsbruck, A-6020 Innsbruck, Austria. Natl Inst Stand & Technol, Boulder, CO USA. Univ Konstanz, D-7750 Constance, Germany. RP Leibfried, D (reprint author), Univ Innsbruck, A-6020 Innsbruck, Austria. RI Monroe, Christopher/G-8105-2011; Pfau, Tilman/G-1774-2011 NR 17 TC 58 Z9 59 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD APR PY 1998 VL 51 IS 4 BP 22 EP 28 DI 10.1063/1.882256 PG 7 WC Physics, Multidisciplinary SC Physics GA ZF498 UT WOS:000072903500005 ER PT J AU Lowry, LF Frost, KJ Davis, R DeMaster, DP Suydam, RS AF Lowry, LF Frost, KJ Davis, R DeMaster, DP Suydam, RS TI Movements and behavior of satellite-tagged spotted seals (Phoca largha) in the Bering and Chukchi Seas SO POLAR BIOLOGY LA English DT Article ID NORTHWEST GREENLAND; HARBOR; TELEMETRY; VITULINA; TRACKING AB Satellite-linked tags were attached to 12 spotted seals (Phoca largha) captured at a coastal lagoon in the eastern Chukchi Sea during August 1991-1993. Movements of seals were tracked for 32-298 days using the Argos system. Of 9,651 total location records obtained, 7,268 were usable. Individual seals were located on 41-96% of the days that tags were operational. During August-November, tagged seals alternated haulouts at coastal sites lasting 1-304 h with trips to sea of 14-901 h. Coastal haul-outs occurred at 14 sites in western Alaska and eastern Russia. On several trips to sea, seals covered distances of more than 1,000 km. Movement southward from the Chukchi Sea generally began in October, with most of the seals passing through the Bering Strait during November. Seals first hauled out on sea ice in October (Chukchi Sea) or November (Bering Sea), and generally moved southward during October-December as sea-ice coverage increased. Seven seals, whose transmitters were still operating, spent December to June in the Bering Sea region between Kuskokwim Bay and Anadyr Gulf, which corresponded to the location of the ice front. The seals made active east-west movements within the ice front. Spotted seals are unlike other ice-breeding seals in that they regularly use coastal haul-outs during summer and autumn. Compared to the closely related Pacific harbor seal (Phoca vitulina richardsi), spotted seals make much longer trips to sea and spend longer continuous periods at their haul-outs during summer and autumn. C1 Alaska Dept Fish & Game, Fairbanks, AK 99701 USA. Texas A&M Univ, Dept Marine Biol, Galveston, TX 77553 USA. NOAA, Natl Marine Fisheries Serv, Natl Marine Mammal Lab, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. N Slope Borough Dept Wildlife Management, Barrow, AK 99723 USA. RP Lowry, LF (reprint author), Alaska Dept Fish & Game, 1300 Coll Rd, Fairbanks, AK 99701 USA. NR 33 TC 26 Z9 29 U1 1 U2 14 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4060 J9 POLAR BIOL JI Polar Biol. PD APR PY 1998 VL 19 IS 4 BP 221 EP 230 DI 10.1007/s003000050238 PG 10 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA ZF509 UT WOS:000072904600001 ER PT J AU Phillips, SD Borchardt, B Estler, WT Buttress, J AF Phillips, SD Borchardt, B Estler, WT Buttress, J TI The estimation of measurement uncertainty of small circular features measured by coordinate measuring machines SO PRECISION ENGINEERING-JOURNAL OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Article DE CMM; uncertainty; probe; sampling strategy; circle AB This paper examines the measurement uncertainty of small circular features as a function of the sampling strategy; i.e., the number and distribution of measurement points. Specifically, we examine measuring a circular feature using a three-point sampling strategy in which the angular distance between the points varies from widely spaced, 120 degrees, to closely grouped, a few degrees. Both theoretical and experimental results show that the measurement uncertainty is a strong function of the sampling strategy. The uncertainty is shown to vary by four orders of magnitude as a function of the angular distribution of the measurement points. A conceptual framework for theoretically estimating the measuring uncertainty is described, and good agreement with experiments is obtained when the measurements are consistent with the assumptions of the theoretical model. This paper is an expansion of a previous internal report(1) with additional material on analog probes and probe lobing models. Published by Elsevier Science Inc. C1 NIST, Gaithersburg, MD 20899 USA. RP Phillips, SD (reprint author), NIST, B220,Room B113,Quince Orchard Blvd, Gaithersburg, MD 20899 USA. EM steven.phillips@nist.gov NR 10 TC 44 Z9 46 U1 0 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0141-6359 J9 PRECIS ENG JI Precis. Eng.-J. Am. Soc. Precis. Eng. PD APR PY 1998 VL 22 IS 2 BP 87 EP 97 DI 10.1016/S0141-6359(98)00006-3 PG 11 WC Engineering, Multidisciplinary; Engineering, Manufacturing; Nanoscience & Nanotechnology; Instruments & Instrumentation SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation GA ZZ494 UT WOS:000074735000004 ER PT J AU Almog, O Gallagher, T Tordova, M Hoskins, J Bryan, P Gilliland, GL AF Almog, O Gallagher, T Tordova, M Hoskins, J Bryan, P Gilliland, GL TI Crystal structure of calcium-independent subtilisin BPN ' with restored thermal stability folded without the prodomain SO PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS LA English DT Article DE subtilisin BPN '; proenzyme; protein folding; protein crystallography; thermal stability; calcium binding ID LEAST-SQUARES REFINEMENT; SMALL PROTEINS; X-RAY; COMPLEX; BINDING; CRYSTALLIZATION; GROWTH; STATE AB The three-dimensional structure of a subtilisin BPN' construct that was produced and folded without its prodomain shows the tertiary structure is nearly identical to the wild-type enzyme and not a folding intermediate. The subtilisin BPN' variant, Sbt70, was cloned and expressed in Escherichia coli without the prodomain, the 77-residue N-terminal domain that catalyzes the folding of the enzyme into its native tertiary structure. Sbt70 has the high-affinity calcium-binding loop, residues 75 to 83, deleted. Such calcium-independent forms of subtilisin BPN' refold independently while retaining high levels of activity [Bryan et al., Biochemistry, 31:4937-4945, 1992]. Sbt70 has, in addition, seven stabilizing mutations, K43N, M50F, A73L, Q206V, Y217K, N218S, Q271E, and the active site serine has been replaced with alanine to prevent autolysis. The purified Sbt70 folded spontaneously without the prodomain and crystallized at room temperature. Crystals of Sbt70 belong to space group P2(1)2(1)2(1) with unit cell parameters a = 53.5 Angstrom, b = 60.3 Angstrom, and c = 83.4 Angstrom. Comparison of the refined structure with other high-resolution structures of subtilisin BPN' establishes that the conformation of Sbt70 is essentially the same as that previously determined for other calcium-independent forms and that of other wild-type subtilisin BPN' structures, all folded in the presence of the prodomain. These findings confirm the results of previous solution studies that showed subtilisin BPN' can be refolded into a native conformation without the presence of the prodomain [Bryan et al., Biochemistry 31:4937-4945, 1992]. The structure analysis also provides the first descriptions of four stabilizing mutations, K43N, A73L, Q206V, and Q271E, and provides details of the interaction between the enzyme and the Ala-Leu-Ala-Leu tetrapeptide found in the active-site cleft. (C) 1998 Wiley-Liss, Inc. C1 Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Rockville, MD USA. RP Gilliland, GL (reprint author), Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. EM gary.gilliland@nist.gov NR 35 TC 26 Z9 26 U1 0 U2 2 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0887-3585 J9 PROTEINS JI Proteins PD APR 1 PY 1998 VL 31 IS 1 BP 21 EP 32 DI 10.1002/(SICI)1097-0134(19980401)31:1<21::AID-PROT3>3.0.CO;2-K PG 12 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA ZE824 UT WOS:000072835300003 PM 9552156 ER PT J AU Danzer, K Currie, LA AF Danzer, K Currie, LA CA Commission Gen Aspects Analyt Chem TI Guidelines for calibration in analytical chemistry - Part 1. Fundamentals and single component calibration (IUPAC recommendations 1998) SO PURE AND APPLIED CHEMISTRY LA English DT Article ID LINEAR-REGRESSION; LEAST-SQUARES; NOMENCLATURE; VARIABLES; ERROR AB This IUPAC nomenclature document has been prepared to establish a uniform and meaningful approach to terminology, notation, and formulation for calibration in analytical chemistry. In this first part, general fundamentals of calibration are presented, namely for both relationships of qualitative and quantitative variables (relations between variables characterizing certain types of analytes and measured signals in certain positions of a measured function on the one hand and between variables characterizing the amount or concentration of the chemical species and the intensities of the measured signals, on the other hand). On this basis, the fundamentals of the common single component calibration which models the relationship y = f(x) between the signal intensities y and the amounts or concentrations x of the analyte under given conditions are represented. Additional papers will be prepared dealing with extensive relationships between several signal intensities and analyte contents, namely with multivariate calibration and with optimization and experimental design.. C1 Univ Jena, Inst Inorgan & Analyt Chem, D-07743 Jena, Germany. NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Danzer, K (reprint author), Univ Jena, Inst Inorgan & Analyt Chem, Lessingstr 8, D-07743 Jena, Germany. NR 46 TC 268 Z9 271 U1 1 U2 24 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD APR PY 1998 VL 70 IS 4 BP 993 EP 1014 DI 10.1351/pac199870040993 PG 22 WC Chemistry, Multidisciplinary SC Chemistry GA 104WY UT WOS:000075040100031 ER PT J AU Tolman, HL AF Tolman, HL TI Effects of observation errors in linear regression and bin-average analyses SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE observation error; regression; statistical methods ID SATELLITE SCATTEROMETER; WIND-SPEED; HEIGHT; OCEAN AB Effects of observation errors in linear regression and bin-averaged (BA) validation techniques are investigated using the example of marine wind speeds. It is shown that a conventional linear regression systematically underestimates the slope of the regression line, and systematically overestimates the random model error. A BA analysis systematically underestimates extreme wind speeds, incorporates spurious nonlinearity, and overestimates random model errors. Correction techniques are suggested for studies in which the observation error can be estimated. Using synthetic data the potential of the correction techniques is illustrated, and it is shown that the above errors are generally not negligible for wind speed validation studies. Practical examples consider the random errors of anemometers and wind speed estimates from satellites. These examples highlight the importance of the error corrections, and illustrate the difficulty of estimating observation errors. Finally, it is argued that the well-known symmetric slope regression should not be used for the validation of forecast systems. Although the present study deals with marine wind speeds, its results are expected to be valid for a wide range of validation studies. C1 NOAA, Ocean Modeling Branch, Environm Modeling Ctr, NCEP, Camp Springs, MD 20746 USA. RP Tolman, HL (reprint author), NOAA, Ocean Modeling Branch, Environm Modeling Ctr, NCEP, 5200 Auth Rd,Room 209, Camp Springs, MD 20746 USA. NR 16 TC 16 Z9 16 U1 0 U2 1 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING, BERKS, ENGLAND RG1 7LJ SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD APR PY 1998 VL 124 IS 547 BP 897 EP 917 DI 10.1256/smsqj.54711 PN A PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZK822 UT WOS:000073367200011 ER PT J AU Iyengar, GV AF Iyengar, GV TI Reevaluation of the trace element content in Reference Man SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID NEUTRON-ACTIVATION ANALYSIS; BIOLOGICAL REFERENCE MATERIALS; REFERENCE VALUES; EUROPEAN-COMMUNITY; HUMAN-BLOOD; URBAN-POPULATION; ITALIAN SUBJECTS; QUALITY-CONTROL; SMOKING-HABITS; HUMAN-TISSUES AB Using recent analytical data, the total body content of several trace elements for the 70 kg Reference Man has been reevaluated. The evaluation leads to the following conclusions. For Al, Ba, Cu and F, the present estimates show an increase; for Br, Cs, I, Pb and Zn the average values for the total body content derived from the present evaluation have remained close to the 1975 estimates; for As, Cd and Rb, the total contents have declined; for B, Co and Mn the uncertainty of the 1975 evaluations have been reduced; and for Au and Cr the 1997 estimations are far below the 1975 estimates. Provisional estimates for Ni (4-6.5 mg), Se (14-21 mg) and Si (2000-3000 mg) are proposed for the first time. With respect to dietary intakes, in contrast to the earlier estimates intakes of trace elements were found to be decreased by factors of 2 for Cu, 2-5 for Cr, 5-10 for Cd, Hg and Pb, and > 10 for Ag, As, Co, Li, Sb and V. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Biomineral Sci Int Inc, Bethesda, MD 20817 USA. RP NIST, Bldg 235,Rm B125, Gaithersburg, MD 20899 USA. NR 160 TC 78 Z9 89 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD APR-JUN PY 1998 VL 51 IS 4-6 BP 545 EP 560 DI 10.1016/S0969-806X(97)00202-8 PG 16 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA ZU325 UT WOS:000074185400076 ER PT J AU Chen, SC Lee, K AF Chen, SC Lee, K TI A mixed-mode smart transducer interface for sensors and actuators SO SOUND AND VIBRATION LA English DT Article AB This article discusses some of the key issues of the proposed IEEE P1451.4 standard -the existing mixed-mode transducer communication schemes, the Transducer Electronic Data Sheet (TEDS) requirements, compatibility with legacy systems, and utilization of results of other P1451 developments to leverage existing and emerging sensor-networking technologies. C1 Aeptec Microsyst Inc, Rockville, MD USA. NIST, Gaithersburg, MD 20899 USA. RP Chen, SC (reprint author), Aeptec Microsyst Inc, Rockville, MD USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU ACOUSTICAL PUBL INC PI BAY VILLAGE PA 27101 E OVIATT RD PO BOX 40416, BAY VILLAGE, OH 44140 USA SN 0038-1810 J9 SOUND VIB JI Sound Vib. PD APR PY 1998 VL 32 IS 4 BP 24 EP 27 PG 4 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA ZP821 UT WOS:000073791800005 ER PT J AU Linsky, JL AF Linsky, JL TI Deuterium abundance in the local ISM and possible spatial variations SO SPACE SCIENCE REVIEWS LA English DT Review DE LISM; interstellar medium; deuterium ID INTERSTELLAR-MEDIUM; GHRS OBSERVATIONS; SOLAR-WIND; HST-GHRS; SIRIUS-A; CLOUD; SIGHT; IONIZATION; CAPELLA; RATIO AB Excellent HST/GHRS spectra of interstellar hydrogen and deuterium Lyman-alpha absorption toward nearby stars allow us to identify systematic errors that have plagued earlier work and to measure accurate values of the D/H ratio in local interstellar gas. Analysis of 12 sightlines through the Local Interstellar Cloud leads to a mean value of D/H = (1.50 +/- 0. 10) x 10(-5) with all data points lying within +/-1 alpha of the mean. Whether or not the D/H ratio has different values elsewhere in the Galaxy and beyond is a very important open question that will be one of the major objectives of the Far Ultraviolet Spectroscopic Explorer (FUSE) mission. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. RP Univ Colorado, JILA, Boulder, CO 80309 USA. NR 24 TC 121 Z9 121 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PD APR PY 1998 VL 84 IS 1-2 BP 285 EP 296 DI 10.1023/A:1005048124341 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112AU UT WOS:000075472200029 ER PT J AU Linsky, JL Wilson, TL Rood, RT AF Linsky, JL Wilson, TL Rood, RT TI Local interstellar medium - Summary of working group VI SO SPACE SCIENCE REVIEWS LA English DT Editorial Material DE LISM; interstellar medium; deuterium; He-3; helium-3 AB This report summarizes the issues discussed in Working Group VI concerning the accuracy of measurements of D/H and He-3/H in the local interstellar medium, possible systematic errors, and emerging trends in the results. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. Max Planck Inst Radioastron, D-5300 Bonn, Germany. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. RP Linsky, JL (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 3 TC 3 Z9 3 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD APR PY 1998 VL 84 IS 1-2 BP 309 EP 315 DI 10.1023/A:1005052225249 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112AU UT WOS:000075472200031 ER PT J AU Tans, PP AF Tans, PP TI Oxygen isotopic equilibrium between carbon dioxide and water in soils SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article ID ATMOSPHERIC CO2; O-18 AB Exact mathematical solutions are presented for some simple cases of isotopic equilibration of oxygen-18 between carbon dioxide and water in soils, which is a major component of the O-18 isotopic balance of atmospheric CO2. The soil-to-air exchange is made up of 2 components. First, respiratory CO2 is produced in the soil and escapes to the atmosphere through diffusion. The lighter isotopic species escapes a little more rapidly, enriching the heavier isotopic species in the CO2 left behind in the soil, which is then out of isotopic equilibrium with soil water. Therefore, simultaneously with the escape of gas, there is continuous re-equilibration of CO2 with soil water. The second component of soil-re-air exchange is independent of the production of CO2 in the soil: the invasion of atmospheric CO2 into the soil, where it equilibrates isotopically with the soil moisture before diffusing back out. A consequence for atmospheric isotopic measurements is that, in general, for respired CO2 a plot of the isotopic ratio versus the inverse of the concentration is curved, and that the slope in the vicinity of the ambient concentration may not point towards the isotopic ratio of the net CO2 evolved from the soil. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Tans, PP (reprint author), NOAA, Climate Monitoring & Diagnost Lab, Mailcode R-E-CG1,325 Broadway, Boulder, CO 80303 USA. EM ptans@cmdl.noaa.gov NR 32 TC 69 Z9 69 U1 0 U2 8 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD APR PY 1998 VL 50 IS 2 BP 163 EP 178 DI 10.1034/j.1600-0889.1998.t01-1-00004.x PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZL264 UT WOS:000073415200004 ER PT J AU Murphy, PP Harrison, DE Feely, RA Takahashi, T Weiss, RF Gammon, RH AF Murphy, PP Harrison, DE Feely, RA Takahashi, T Weiss, RF Gammon, RH TI Variability of Delta pCO(2) in the subarctic North Pacific. A comparison of results from four expeditions SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article ID EASTERN EQUATORIAL PACIFIC; ATMOSPHERIC CARBON-DIOXIDE; SEA CO2 EXCHANGE; OCEAN STATION-P; PARTIAL-PRESSURE; EL-NINO; SURFACE WATERS; WIND SPEEDS; ATLANTIC; BUDGET AB Time-space variability of surface seawater pCO(2) is examined over the region (150 degrees W-180 degrees, 46 degrees N-50 degrees N) of the subarctic North Pacific where large meridional gradients of temperature and nutrient concentrations exist. The data were collected during four trans-Pacific expeditions in three different years (1985-1987), but within the same 30-day period of the year (August-September). Systematic measurement differences between the four data sets are estimated as <10 mu atm. The inter-expedition comparison suggests that surface seawater pCO(2) in the study area is quite variable, with mean differences of up to 25 mu atm and local differences up to 60 mu atm. Spatial and interannual variability of surface seawater pCO(2) were found to contribute significant uncertainty to estimates of the mean Delta pCO(2) for the study area. Fluxes were calculated using Delta pCO(2) values from the four expeditions combined with gas exchange coefficients calculated from four different wind fields giving a range of -0.94 to +4.1 mmol CO2 m(-2) d(-1). The range of fluxes from the study area is scaled to a larger area of the North Pacific to address how this variability can translate into uncertainties in basin-wide carbon air-sea exchange fluxes. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92037 USA. Univ Washington, Dept Chem, Seattle, WA 98195 USA. Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. RP Murphy, PP (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI Harrison, Don/D-9582-2013 NR 58 TC 10 Z9 10 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD APR PY 1998 VL 50 IS 2 BP 185 EP 204 DI 10.1034/j.1600-0889.1998.t01-1-00006.x PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZL264 UT WOS:000073415200006 ER PT J AU Butler, JM Levin, BC AF Butler, JM Levin, BC TI Forensic applications of mitochondrial DNA SO TRENDS IN BIOTECHNOLOGY LA English DT Article ID MTDNA CONTROL REGION; HUMAN REMAINS; SEQUENCE POLYMORPHISMS; SKELETAL REMAINS; RAPID DETECTION; D-LOOP; IDENTIFICATION; AMPLIFICATION; HETEROPLASMY; POPULATION AB Human mitochondrial DNA has become a useful tool in forensic investigations. Its polymorphic nature and maternal inheritance are characteristics that have, combined with its sequence information, enabled investigators to identify missing persons, war casualties and individuals involved in mass disasters and criminal cases. Various screening procedures have been developed to reduce the need to sequence samples that do not match, but DNA-sequence information is still necessary to verify a match. Even though several challenges remain before mitochondrial-DNA-sequence information can be used unambiguously, comparative mitochondrial-DNA-sequence analysis appears to be a reliable and powerful means for human identification. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Butler, JM (reprint author), NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. EM barbara.levin@nist.gov RI Butler, John/C-7812-2011 NR 38 TC 43 Z9 46 U1 1 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-7799 J9 TRENDS BIOTECHNOL JI Trends Biotechnol. PD APR PY 1998 VL 16 IS 4 BP 158 EP 162 DI 10.1016/S0167-7799(98)01173-1 PG 5 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA ZG247 UT WOS:000072981900005 PM 9586238 ER PT J AU Cappellato, R Peters, NE Meyers, TP AF Cappellato, R Peters, NE Meyers, TP TI Above-ground sulfur cycling in adjacent coniferous and deciduous forests and watershed sulfur retention in the Georgia Piedmont, USA SO WATER AIR AND SOIL POLLUTION LA English DT Article DE atmospheric deposition; coniferous; deciduous; dendrochemistry; dry deposition; foliage; loblolly pine; precipitation; stemflow; sulfur; sulfur dioxide; throughfall ID INFERENTIAL MEASUREMENT TECHNIQUES; DRY-DEPOSITION; UNITED-STATES; CANOPY INTERACTIONS; PANOLA-MOUNTAIN; SULFATE; THROUGHFALL; SO2; SURFACES; TREES AB Atmospheric deposition and above-ground cycling of sulfur (S) were evaluated in adjacent deciduous and coniferous forests at the Panola Mountain Research Watershed (PMRW), Georgia, U.S.A. Total atmospheric S deposition (wet plus dry) was 12.9 and 12.7 kg ha(-1) yr(-1) for the deciduous and coniferous forests, respectively, from October 1987 through November 1989. Dry deposition contributes more than 40% to the total atmospheric S deposition, and SO2 is the major source (similar to 55%) of total dry S deposition. Dry deposition to these canopies is similar to regional estimates suggesting that 60-km proximity to emission sources does not noticeably impact dry deposition at PMRW. Below-canopy S fluxes (throughfall plus stemflow) in each forest are 37% higher annually in the deciduous forest than in the coniferous forest. An excess in below-canopy S flux in the deciduous forest is attributed to leaching and higher dry deposition than in the coniferous forest. Total S deposition to the forest floor by throughfall, stemflow and litterfall was 2.4 and 2.8 times higher in the deciduous and coniferous forests, respectively, than annual S growth requirement for foliage and wood. Although S deposition exceeds growth requirement, more than 95% of the total atmospheric S deposition was retained by the watershed in 1988 and 1989. The S retention at PMRW is primarily due to SO42- adsorption by iron oxides and hydroxides in watershed soils. The S content in white oak and loblolly pine boles have increased more than 200% in the last 20 yr, possibly reflecting increases in emissions. C1 Emory Univ, Human & Nat Ecol Program, Atlanta, GA 30322 USA. US Geol Survey, Atlanta, GA 30360 USA. NOAA, Air Resources Lab, Oak Ridge, TN 37831 USA. RP Cappellato, R (reprint author), Emory Univ, Human & Nat Ecol Program, Atlanta, GA 30322 USA. RI Meyers, Tilden/C-6633-2016 NR 51 TC 5 Z9 7 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD APR PY 1998 VL 103 IS 1-4 BP 151 EP 171 DI 10.1023/A:1004902816609 PG 21 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA ZC638 UT WOS:000072601600011 ER PT J AU Szaro, RC Berc, J Cameron, S Cordle, S Crosby, M Martin, L Norton, D O'Malley, R Ruark, G AF Szaro, RC Berc, J Cameron, S Cordle, S Crosby, M Martin, L Norton, D O'Malley, R Ruark, G TI The ecosystem approach: science and information management issues, gaps and needs SO LANDSCAPE AND URBAN PLANNING LA English DT Article DE ecological approach; information management; role of science AB Changing public expectations and increased public involvement have challenged traditional management policies and practices. And with these challenges, the need for scientific information as a foundation for resource management decisions continues to increase dramatically especially when policy and management decisions are highly dependent on the quality and quantity of the available information and science. To facilitate this, the interface between social, economic, physical-biological, and ecological models must be improved. New and existing research results have to be assembled and formatted into packages that are usable by managers and decision-makers so that they are able to reasonably predict the future condition of resources resulting from management options. This study identified several key gaps in the science base needed for the implementation of ecosystem management including: ecology on multiple scales, multiple species science, monitoring and evaluation, 'benchmarks' of ecosystem condition, socioeconomic sciences and valuation, human dimensions of natural resource use, ecological restoration technology development, quantifying uncertainty and assessing risk, modeling, and the adaptive management process. However, the major lessons learned through this study are that, whereas it may be important to identify key scientific gaps, the barriers and their solutions may be more social or institutional than scientific in nature. (C) 1998 Elsevier Science B.V. C1 US Forest Serv, USDA, Washington, DC 20090 USA. John Hansen Business Ctr, Nat Resources Conservat Serv, Annapolis, MD 21401 USA. Off Management & Budget, Nat Resource Div, Washington, DC 20503 USA. US EPA, Natl Ctr Environm Assessments 8601, Washington, DC 20460 USA. NOAA, Silver Spring, MD 20910 USA. USA, Corps Engineers, Water Resources Support Ctr, Alexandria, VA 22315 USA. US EPA, Off Wetlands Oceans & Watersheds 4503F, Assessment & Watershed Protect Div, Washington, DC 20460 USA. US Dept Interior, Washington, DC 20240 USA. Execut Off President, Environm Div, Off Sci & Technol Policy, Washington, DC 20500 USA. RP Szaro, RC (reprint author), Int Union Forestry Res Org IUFRO, Special Programme Dev Countries, Seckendorff Guden Weg 8, A-1131 Vienna, Austria. NR 5 TC 22 Z9 24 U1 2 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-2046 J9 LANDSCAPE URBAN PLAN JI Landsc. Urban Plan. PD MAR 31 PY 1998 VL 40 IS 1-3 BP 89 EP 101 DI 10.1016/S0169-2046(97)00101-1 PG 13 WC Ecology; Environmental Studies; Geography; Geography, Physical; Urban Studies SC Environmental Sciences & Ecology; Geography; Physical Geography; Urban Studies GA ZV370 UT WOS:000074297800009 ER PT J AU Meuse, CW Niaura, G Lewis, ML Plant, AL AF Meuse, CW Niaura, G Lewis, ML Plant, AL TI Assessing the molecular structure of alkanethiol monolayers in hybrid bilayer membranes with vibrational spectroscopies SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; ENHANCED RAMAN-SCATTERING; ALKYL THIOL MONOLAYERS; GOLD SURFACES; LIPID BILAYERS; DISTANCE DEPENDENCE; PHASE-BEHAVIOR; FILMS; ELECTRODES; LAYERS AB Hybrid bilayer membranes (HBMs), consisting of a lipid monolayer covering a self-assembled alkanethiol monolayer on a metal surface, are useful models for studying the structure and function of cell membranes. Surface-enhanced Raman spectroscopy (SERS) and reflection absorption infrared spectroscopy (RAIRS) are used to study HBMs with various alkanethiol and lipid components. Together, these two techniques clearly indicate that the lipid forms a well-ordered, non-interdigitated layer on the alkanethiol with the head groups of the lipids oriented away from the metal surface. Both techniques reveal that the formation of an HEM produces small changes in the alkanethiols, which are similar to those caused by a reduction in temperature, indicative of an increase in order. The small magnitude of the perturbations in the alkanethiol monolayer upon addition of the lipid layer will simplify the further study of HBMs. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Meuse, CW (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 51 TC 78 Z9 79 U1 2 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR 31 PY 1998 VL 14 IS 7 BP 1604 EP 1611 DI 10.1021/la9700679 PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA ZF614 UT WOS:000072914700020 ER PT J AU Assel, R Rodionov, S AF Assel, R Rodionov, S TI Atmospheric teleconnections for annual maximum ice cover on the Laurentian Great Lakes SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE Laurentian Great Lakes; teleconnections; lake ice; North America; 700 hPa Northern Hemisphere anomalies; ENSO ID NORTHERN HEMISPHERE WINTER; MICHIGAN; PATTERNS; WEATHER; TEMPERATURES AB Great Lake ice cover records for winters 1963-1990 were used to define anomalously high (low) average ice cover based on the seven highest (seven lowest) annual maximum ice covers. Analysis of the maximum ice cover reveals (i) a low (1964-1976); (ii) a high (1977-1982); and (iii) once again a low (1983-1990) ice cover regime. The high ice cover regime corresponded in part with a hiatus in El Nino-Southern Oscillation (ENSO) events and the beginning of an interdecadal change in Northern Hemisphere atmospheric circulation that started in the late 1970s. About 46% of the lowest quartile ice covers occurred during the mature phase (year + one winter) of El Nino. Only 1 year out of seven with the mature phase of El Nino between 1963 and 1990 was not associated with the lowest quartile ice cover, this was 1977, a pivotal year after which a new climatic regime in the Northern Hemisphere was established. Anomaly maps of 700 hPa geopotential height for the lowest quartile ice cover reveal a zonal flow pattern. Highest quartile ice cover was associated with meridonal circulation from the Arctic directed toward the Great Lakes. Significant differences occur for highest minus lowest quartile ice cover composite 700 hPa height anomaly maps in the Pacific Ocean, the west coast of North America, north Mexico, eastern North America, north central Siberia, western Europe and the adjacent North Atlantic. Correlations between first differences (year t+1 minus year t) of annual maximum ice cover and 700 hPa geopotential heights for winters 1963-1990 agrees with these teleconnections and were higher than the absolute time series correlations, indicating strong interannual teleconnections. Annual maximum ice cover was also significantly correlated with the tropical Northern Hemisphere teleconnection index. (C) 1998 Royal Meteorological Society. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Colorado, Dept Comp Sci, Ctr Engn, ECOT 7 15, Boulder, CO 80309 USA. RP Assel, R (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. OI Rodionov, Sergei/0000-0002-5318-9746 NR 37 TC 29 Z9 29 U1 1 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD MAR 30 PY 1998 VL 18 IS 4 BP 425 EP 442 DI 10.1002/(SICI)1097-0088(19980330)18:4<425::AID-JOC258>3.0.CO;2-Q PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZJ656 UT WOS:000073238900005 ER PT J AU Haywood, JM Ramaswamy, V AF Haywood, JM Ramaswamy, V TI Global sensitivity studies of the direct radiative forcing due to anthropogenic sulfate and black carbon aerosols SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERIC AEROSOLS; GREENHOUSE GASES; CLIMATE; MODEL; SIZE; ALBEDO; BUDGET; CLOUDS; ABSORPTION; TRANSPORT AB The direct radiative forcing (DRF) of sulfate and black carbon (BC) aerosols is investigated using a new multispectral radiation code within the R30 Geophysical Fluid Dynamics Laboratory general circulation model (GCM). Two independent sulfate climatologies from chemical transport models are applied to the GCM; each climatology has a different atmospheric burden, vertical profile, and seasonal cycle. The DRF is calculated to be approximately -0.6 and -0.8 W m(-2) for the different sulfate climatologies. Additional sensitivity studies show that the vertical profile of the sulfate aerosol is important in determining the DRF; sulfate residing near the surface gives the strongest DRF due to the effects of relative humidity. Calculations of the DRF due to BC reveal that the DRF remains uncertain to approximately a factor of 3 due to uncertainties in the total atmospheric burden, the vertical profile of the BC, and the assumed size distribution. Because of the uncertainties in the total global mass of BC, the normalized DRF (the DRF per unit column mass of aerosol in watts per milligram (W mg(-1))) due to BC is estimated; the range is +1.1 to +1.9 W mg(-1) due to uncertainties in the vertical profile. These values correspond to a DRF of approximately +0.4 W m(-2) with a factor of 3 uncertainty when the uncertainty in the total global mass of BC is included. In contrast to sulfate aerosol, the contribution to the global DRF from cloudy regions is very significant, being estimated as approximately 60%. The vertical profile of the BC is, once again, important in determining the DRF, but the sensitivity is reversed from that of sulfate; BC near the surface gives the weakest DRF due to the shielding effects of overlying clouds. Although the uncertainty in the estimates of the DRF due to BC remains high, these results indicate that the DRF due to absorption by BC aerosol may contribute a significant positive radiative forcing and may consequently be important in determining climatic changes in the Earth-atmosphere system. C1 Princeton Univ, GFDL, Princeton, NJ 08542 USA. Princeton Univ, AOS Program, Princeton, NJ 08542 USA. RP Haywood, JM (reprint author), DERA, Met Res Flight, Meteorol Off, Farnborough GU14 0LX, Hants, England. EM jmhaywood@meto.gov.uk NR 51 TC 286 Z9 300 U1 2 U2 35 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 27 PY 1998 VL 103 IS D6 BP 6043 EP 6058 DI 10.1029/97JD03426 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZD911 UT WOS:000072737800008 ER PT J AU Gillette, DA Marticorena, B Bergametti, G AF Gillette, DA Marticorena, B Bergametti, G TI Change in the aerodynamic roughness height by saltating grains: Experimental assessment, test of theory, and operational parameterization SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB Data from an experiment at Owens Lake provided an opportunity to verify the validity of Raupach's formula that predicts the apparent roughness height at equilibrium with saltation during wind erosion episodes. In addition to that verification, a simplification of Raupach's formula is presented which allows the computation of the wind friction velocity affected by saltating sand grains without the need to measure the threshold wind friction velocity and to do iterative calculations. This method estimates the increase of the wind friction velocity Delta u*, above the nonsaltating wind friction velocity caused by the saltating grains: Delta u* = 0.3 [U -U-t](2) where U and U-t are the wind speed and the threshold wind speed, respectively, at 10 m. C1 NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27711 USA. Univ Paris 07, Lab Interuniv Syst Atmospher, Creteil, France. Univ Paris 12, Lab Interuniv Syst Atmospher, Creteil, France. RP Gillette, DA (reprint author), NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27711 USA. EM gillette.dale@epamail.epa.gov NR 11 TC 34 Z9 35 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 27 PY 1998 VL 103 IS D6 BP 6203 EP 6209 DI 10.1029/98JD00207 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZD911 UT WOS:000072737800021 ER PT J AU Jameson, AR Kostinski, AB Black, RA AF Jameson, AR Kostinski, AB Black, RA TI The texture of clouds SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ENTRAINMENT; GROWTH AB Using a precise definition of clustering, it is shown that in two tropical cumulus clouds, droplets appear to be bunched over distances ranging from at least a kilometer or more down to several centimeters. A statistical framework is proposed for quantifying clustering in terms of a Poisson probability mixture. While these observations require further substantiation in many different clouds, droplet clustering may play a role in diverse phenomena from the coalescence growth of raindrops to the scattering of radiation by clouds. C1 RJH Sci Inc, Alexandria, VA 22303 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Michigan Technol Univ, Dept Phys, Houghton, MI 49931 USA. RP Jameson, AR (reprint author), RJH Sci Inc, 5904 Richmond Hwy,Ste 401, Alexandria, VA 22303 USA. EM jameson@rjhsci.com RI Black, Robert/C-9617-2009 OI Black, Robert/0000-0001-6938-125X NR 26 TC 12 Z9 12 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 27 PY 1998 VL 103 IS D6 BP 6211 EP 6219 DI 10.1029/98JD00081 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZD911 UT WOS:000072737800022 ER PT J AU Lovejoy, ER Wilson, RR AF Lovejoy, ER Wilson, RR TI Kinetic studies of negative ion reactions in a quadrupole ion trap: Absolute rate coefficients and ion energies SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID INVERSE FOURIER-TRANSFORM; MASS-SPECTROMETRY; BUFFER-GAS; CHEMISTRY; TEMPERATURE; DEPENDENCE; METHANOL; AFFINITY; REGION; WATER AB A new apparatus consisting of an ion-molecule reactor coupled to a quadrupole ion trap is described. The kinetics and products of the rapid reactions of SF6- with SO2, HNO3, and HCl in the ion trap are reported. There is excellent agreement between the ion trap rate coefficients and yields, and flowing afterglow results. Rate coefficients for reactions of products of the SF6- reactions are also reported. Measurements of the equilibrium constant for the reaction NO3-. HNO3+HNO3 reversible arrow NO3-.(HNO3)(2) in the ion trap provide a very sensitive measure of the energy of the trapped ions. These measurements indicate that the effective temperature of the trapped NO3-.(HNO3)(2) ion is 320 +/- 30 K for an ion trap at 298 K (1-2 mTorr He, q(z) = 0.074). The presence of 0.2 mTorr N-2 buffer gas increases the internal temperature of the trapped ions by about 10 K. The internal temperature is also a weak function of the trapping potential, increasing by about 10 K over the range 0.074 < q(z) < 0.286. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Lovejoy, ER (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. NR 34 TC 25 Z9 25 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 26 PY 1998 VL 102 IS 13 BP 2309 EP 2315 DI 10.1021/jp973391l PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZF506 UT WOS:000072904300010 ER PT J AU Zhou, CL Hobbie, EK Bauer, BJ Sung, L Jiang, M Han, CC AF Zhou, CL Hobbie, EK Bauer, BJ Sung, L Jiang, M Han, CC TI Control of interaction strength in hydrogen-bonded polymer blends via the density of the hydroxyl group SO MACROMOLECULES LA English DT Article ID SPINODAL DECOMPOSITION; THERMODYNAMICS; MISCIBILITY; METHACRYLATE); POLYSTYRENE; MIXTURES AB Deuterium-labeled polystyrene modified by random distributions of the comonomer p-(1,1,1,3,3,3-hexafluoro-2-hydroxyisopropyl)-alpha- methylstyrene [DPS(OH)] has been blended with poly(butyl methacrylate) (PBMA) and studied with small-angle neutron scattering(SANS). Miscibility is induced via hydrogen bonding between the DPS(OH) hydroxyl group and PBMA carbonyl groups. As the density of the hydroxyl group increases, the susceptibilities of the related blends decrease, while those of the pure DPS(OH) increase. The extrapolated spinodal temperature increases linearly with comonomer density, and the hydrogen-bond enthalpy deduced from the SANS data is in good agreement with previously reported values. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. Fudan Univ, Inst Macromol Sci, Shanghai 200433, Peoples R China. RP Hobbie, EK (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. RI Hobbie, Erik/C-8269-2013 NR 17 TC 8 Z9 8 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAR 24 PY 1998 VL 31 IS 6 BP 1937 EP 1941 DI 10.1021/ma971098d PG 5 WC Polymer Science SC Polymer Science GA ZE039 UT WOS:000072751200031 ER PT J AU Flanagan, TB Clewley, JD Noh, H Barker, J Sakamoto, Y AF Flanagan, TB Clewley, JD Noh, H Barker, J Sakamoto, Y TI Hydrogen-induced lattice migration in Pd-Pt alloys SO ACTA MATERIALIA LA English DT Article ID RH ALLOYS; PHASE-DIAGRAM; SYSTEM; SOLUBILITY; PRESSURES; RANGE AB Initially homogeneous, f.c.c. Pd-Pt alloys are shown to partially separate into Pd-rich and Pd-poor regions as a result of exposure to hydrogen gas at, e.g. 5.5 MPa, and at moderately high temperatures, e.g. 448 K. After this hydrogen heat treatment, HHT, the hydrogen can be removed by evacuation at T less than or equal to 448 K, leaving a metastable alloy which can then be analyzed for the degree of its phase separation. The presence of the phase separation is demonstrated primarily from changes of diagnostic hydrogen isotherms measured at a lower temperature before and after HHT, but also from Auger depth-profiling analysis, high resolution electron microscopy and small angle neutron scattering (SANS). After heating at the same temperature in the absence of the dissolved hydrogen, no evidence for phase separation is found. The X-Pt=0.15, 0.20 and 0.25 alloys, which do not form hydride phases in their homogeneous forms at T greater than or equal to 273 K, develop plateau pressure regions indicative of hydride formation in their diagnostic isotherms (greater than or equal to 273 K) after HHT at 100 MPa (673 K). This is possible because significant phase separation has occurred due to HHT resulting in a phase capable of forming a hydride at 273 K, i.e. X-Pt<0.15. These alloys, which have undergone phase separation at 673 K, return to their initial, homogeneous states after annealing in vacuo at the same temperature. i.e. 673 K. This proves that there is no binary Pd-Pt miscibility gap for the temperatures and compositions examined. It is suggested, instead, that phase separation results from a ternary (Pd + Pd + H) equilibrium which causes hydrogen-induced segregation of the metal atoms relative to the initial, homogeneous alloy. The rates of recovery of the phase separated, metastable alloys back towards their homogeneous form are significantly enhanced by the presence of smaller concentrations of dissolved hydrogen than required for the significant phase separation. Thus at a moderate temperature, e.g. 673 K, large concentrations of dissolved hydrogen cause phase separation, whereas smaller concentrations enhance the return towards an intermediate, more homogeneous, state. (C) 1998 Acta Metallurgica Inc. C1 Univ Vermont, Mat Sci Program, Burlington, VT 05405 USA. Univ Vermont, Dept Chem, Burlington, VT 05405 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Nagasaki Univ, Dept Mat Sci, Nagasaki 852, Japan. RP Flanagan, TB (reprint author), Univ Vermont, Mat Sci Program, Burlington, VT 05405 USA. NR 28 TC 15 Z9 16 U1 1 U2 9 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 MAR 23 PY 1998 VL 46 IS 6 BP 2173 EP 2183 DI 10.1016/S1359-6454(97)00433-3 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZF480 UT WOS:000072901700028 ER PT J AU Block, BA Dewar, H Williams, T Prince, ED Farwell, C Fudge, D AF Block, BA Dewar, H Williams, T Prince, ED Farwell, C Fudge, D TI Archival and pop - Up satellite tagging of bluefin tuna SO FASEB JOURNAL LA English DT Meeting Abstract C1 Stanford Univ, Tuna Res & Conservat Ctr, Pacific Grove, CA 93950 USA. Monterey Bay Aquarium Res Inst, Pacific Grove, CA 93950 USA. NMFS, SE Fisheries Ctr, Miami, FL 33149 USA. NR 0 TC 1 Z9 2 U1 0 U2 3 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 20 PY 1998 VL 12 IS 5 SU S MA 3926 BP A676 EP A676 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 121HD UT WOS:000076006500308 ER PT J AU Ferruzzi, MG Sander, LC Rock, CL Schwartz, SJ AF Ferruzzi, MG Sander, LC Rock, CL Schwartz, SJ TI Carotenoid determination in biological microsamples using liquid chromatography with a coulometric electrochemical array detector. SO FASEB JOURNAL LA English DT Meeting Abstract C1 Ohio State Univ, Dept Food Sci & Technol, Columbus, OH 43210 USA. NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. Univ Calif San Diego, Dept Family & Prevent Med, La Jolla, CA 92093 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 20 PY 1998 VL 12 IS 5 SU S MA 5603 BP A967 EP A967 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 121HD UT WOS:000076006501984 ER PT J AU Srinivas, VR Singha, NC Schwarz, FP Surolia, A AF Srinivas, VR Singha, NC Schwarz, FP Surolia, A TI Differential scanning calorimetric studies of the glycoprotein, winged bean acidic lectin, isolated from the seeds of Psophocarpus tetrogonolobus SO FEBS LETTERS LA English DT Article DE scanning calorimetry; WBAII; quaternary association; denaturation temperature ID THERMAL-DENATURATION; BINDING; THERMODYNAMICS; TETRAGONOLOBUS; MONOSACCHARIDE AB Differential scanning calorimetry of solutions of WBAII and in presence of sugar ligands shows that WBAII dimer dissociates to its constituent monomeric subunits at the denaturation temperature, The thermal denaturation of WB;UI consists of the unfolding of two independent domains of WBAII similar to that of basic winged bean lectin and ECorL and in contrast to concanavalin A (conA), pea and lentil lectin, which unfold as single entities. Apparently, the glycosylation reduces the structural integrity of WBAII as compared to conA, pea and lentil Lectin, The increase in the denaturation temperature of the sugar-lectin complexes yields binding constants close to the binding constants extrapolated from the ITC results and confirms the mechanism proposed for its thermal unfolding. (C) 1998 Federation of European Biochemical Societies. C1 Indian Inst Sci, Mol Biophys Unit, Bangalore 560012, Karnataka, India. Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NIST, Rockville, MD 20850 USA. RP Surolia, A (reprint author), Indian Inst Sci, Mol Biophys Unit, Bangalore 560012, Karnataka, India. RI SUROLIA, AVADESHA/C-5442-2009 NR 12 TC 14 Z9 14 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-5793 J9 FEBS LETT JI FEBS Lett. PD MAR 20 PY 1998 VL 425 IS 1 BP 57 EP 60 DI 10.1016/S0014-5793(98)00197-5 PG 4 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA ZE342 UT WOS:000072783000011 PM 9541006 ER PT J AU Levin, I Gemming, T Brandon, DG AF Levin, I Gemming, T Brandon, DG TI Some metastable polymorphs and transient stages of transformation in alumina SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article ID MARTENSITIC-TRANSFORMATION; PHASE AB Meastable alumina phases developed in plasma sprayed alumina were studied by both electron diffraction and high-resolution transmission electron microscopy. A new alumina polymorph with monoclinic symmetry, denoted theta "-Al2O3, was identified. The crystal structure of theta "-Al2O3 was described by the A12/n1 space, group and a unit cell containing 160 ions with lattice parameters a approximate to 3/2 a(gamma), b = a(gamma) root 2, c = a gamma root 2, beta approximate to 104 degrees (a gamma is the lattice parameter of gamma-Al2O3). The space group of orthorhombic delta-Al2O3 with lattice parameters a = 2a(gamma), b = a(gamma), and c = 3/2 a(gamma) was determined to be P2(1)2(1)2. All ordered metastable alumina phases which have been identified theta " (monoclinic), lambda (monoclinic), and delta (orthorhombic)) were proposed to evolve from gamma-Al2O3 by the cation ordering on interstitial sites of the f.c.c. packed oxygen sublattice. The analysis of transient stages of both gamma-->delta and gamma-->lambda transformations showed that the cation filling of interstitial positions within the oxygen sublattice is strongly correlated, which results in the formation of the cation-vacancy clusters. C1 Technion Israel Inst Technol, Fac Met Engn, IL-32000 Haifa, Israel. Max Planck Inst Met Forsch, D-70174 Stuttgart, Germany. RP Levin, I (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. RI Levin, Igor/F-8588-2010; Gemming, Thomas/D-3920-2015 OI Gemming, Thomas/0000-0002-7353-595X NR 24 TC 18 Z9 18 U1 0 U2 15 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD MAR 16 PY 1998 VL 166 IS 1 BP 197 EP 218 DI 10.1002/(SICI)1521-396X(199803)166:1<197::AID-PSSA197>3.3.CO;2-Z PG 22 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZG193 UT WOS:000072976500019 ER PT J AU Donati, C Douglas, JF Kob, W Plimpton, SJ Poole, PH Glotzer, SC AF Donati, C Douglas, JF Kob, W Plimpton, SJ Poole, PH Glotzer, SC TI Stringlike cooperative motion in a supercooled liquid SO PHYSICAL REVIEW LETTERS LA English DT Article ID LENNARD-JONES MIXTURE; MODE-COUPLING THEORY; SOFT-SPHERE ALLOYS; GLASS-TRANSITION; STRUCTURAL RELAXATION; MULTIDIMENSIONAL NMR; MOLECULAR-DYNAMICS; BETA-RELAXATION; LIVING POLYMERS; O-TERPHENYL AB Extensive molecular dynamics simulations are performed on a glass-forming Lennard-Jones mixture to determine the nature of the cooperative motions occurring in this model fragile liquid. We observe stringlike cooperative molecular motion ("strings") at temperatures well above the glass transition. The mean length of the strings increases upon cooling, and the string length distribution is found to be nearly exponential. C1 NIST, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. NIST, Div Polymers, Gaithersburg, MD 20899 USA. Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany. Sandia Natl Labs, Parallel Computat Sci Dept, Albuquerque, NM 87185 USA. Univ Western Ontario, Dept Appl Math, London, ON N6A 5B7, Canada. RP Glotzer, SC (reprint author), NIST, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. EM sharon.glotzer@nist.gov RI Poole, Peter/C-7943-2009; Donati, Claudio/J-5180-2012; Kob, Walter/L-7010-2013; OI Poole, Peter/0000-0001-5985-0585; Kob, Walter/0000-0001-7405-2178; Donati, Claudio/0000-0001-8688-1651 NR 50 TC 640 Z9 642 U1 2 U2 78 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 MAR 16 PY 1998 VL 80 IS 11 BP 2338 EP 2341 DI 10.1103/PhysRevLett.80.2338 PG 4 WC Physics, Multidisciplinary SC Physics GA ZC385 UT WOS:000072572700021 ER PT J AU de Gouw, JA Lovejoy, ER AF de Gouw, JA Lovejoy, ER TI Reactive uptake of ozone by liquid organic compounds SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRACE GASES; SURFACES; AEROSOL AB The reaction probability of ozone on the surface of several different organic liquids is measured. Ozone reacts efficiently (gamma approximate to 10(2)-10(-3)) with organic liquids containing double bonds (1-tridecene, alpha-pinene, toluene, methacrolein and canola oil), and much less efficiently with an aldehyde, a ketone (tridecanal, 2-tridecanone; gamma approximate to 10(-4)), an alkane, an alcohol and an acid (tridecane, 1-tridecanol, tridecanoic acid; gamma less than or equal to 10(-5)). The results suggest that heterogeneous reactions with organic aerosol can bean important loss process for tropospheric ozone, if the aerosol contains unsaturated organic material. C1 NOAA, Aeron Lab, Environm Res Labs, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP de Gouw, JA (reprint author), NOAA, Aeron Lab, Environm Res Labs, 325 Broadway, Boulder, CO 80303 USA. RI de Gouw, Joost/A-9675-2008 OI de Gouw, Joost/0000-0002-0385-1826 NR 25 TC 68 Z9 70 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 15 PY 1998 VL 25 IS 6 BP 931 EP 934 DI 10.1029/98GL00515 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZD051 UT WOS:000072645900044 ER PT J AU Bennett, HS AF Bennett, HS TI High dopant and carrier concentration effects in gallium aluminum arsenide: Densities of states and effective intrinsic carrier concentrations SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MULTIPLE-SCATTERING APPROACH; MINORITY ELECTRON; HOLE MOBILITIES; IMPURITY BANDS; GAAS; SILICON; SEMICONDUCTORS; MAJORITY AB The changes in carrier densities of states and effective intrinsic carrier concentrations due to high dopant and carrier concentration effects in Ga1-yAlyAs are calculated at 300 K for donor densities between 10(16) and 10(19) cm(-3) and for acceptor densities between 10(16) and 10(20) cm(-3). The mole fraction of AlAs, y, varies between 0.0 and 0.3 in these calculations. The Klauder self-energy method (fifth level of approximation) is used to describe the effects of carrier-dopant ion interactions on the conduction and valence bands and their densities of states. The effects of carrier-carrier interactions (majority-carrier exchange and minority-carrier correlation) are calculated by extending the work of Abram et al. to include both finite wave numbers and finite temperatures. This article is the first reported use of one theory to treat both sides of the Mott transition. Namely, solutions of the very nonlinear integral equations that result from the Klauder fifth-level approximation are obtained for low-dopant densities that involve-bath bound and continuum states and for high-dopant densities that involve primarily continuum states. The results show that quantitatively significant changes occur in densities of states, locations of band edges, and effective intrinsic-carrier concentrations from the values usually used by researchers, particularly, from those values found in most device simulators. These results are important for predictive simulations of optoelectronic, microwave, and electronic devices because such computer simulations require physically reasonable values of the changes in the locations of band edges, densities of states, and effective intrinsic carrier concentrations. C1 NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Bennett, HS (reprint author), NIST, Div Semicond Elect, Bldg 225,Room B344, Gaithersburg, MD 20899 USA. EM herbert.bennett@nist.gov NR 20 TC 22 Z9 22 U1 0 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAR 15 PY 1998 VL 83 IS 6 BP 3102 EP 3110 DI 10.1063/1.367127 PG 9 WC Physics, Applied SC Physics GA ZC998 UT WOS:000072640700036 ER PT J AU Kim, JH Sosso, A Clark, AF AF Kim, JH Sosso, A Clark, AF TI Dynamics of overdamped Josephson junctions driven by a square-wave pulse SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID VOLTAGE STANDARDS AB The periodic solutions of an overdamped Josephson junction driven by a square-wave pulse were found. Unlike those driven by a sinusoidal ac current, the integer step widths of a Josephson junction driven by a square-wave pulse train are reduced with increasing ac current frequency. The maximum value of any non-zero step width approaches 2I(c), where I-c is the critical current, by decreasing either the pulse repetition rate or the pulse duration time. The characteristic features of any integer step are almost identical and we give an explanation of this. (C) 1998 American Institute of Physics. C1 Korea Res Inst Stand & Sci, Elect Grp, Taejon 305600, South Korea. Ist Elettrotecn Nazl Galileo Ferraris, I-10135 Turin, Italy. NIST, MET B258, Gaithersburg, MD 20899 USA. RP Kim, JH (reprint author), Korea Res Inst Stand & Sci, Elect Grp, POB 102, Taejon 305600, South Korea. EM jinhee@krissol.kriss.re.kr NR 15 TC 11 Z9 11 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAR 15 PY 1998 VL 83 IS 6 BP 3225 EP 3232 DI 10.1063/1.367089 PG 8 WC Physics, Applied SC Physics GA ZC998 UT WOS:000072640700055 ER PT J AU Moore, DW Kloosterziel, RC Kessler, WS AF Moore, DW Kloosterziel, RC Kessler, WS TI Evolution of mixed Rossby gravity waves SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID BAROCLINIC OCEAN MOTIONS; WESTERN INDIAN-OCEAN; EQUATORIAL OCEAN; MODEL; CURRENTS; 26-DAY AB A Green's function is derived, which can be used to study and predict the evolution of the velocity and pressure fields associated with the mixed Rossby gravity wave component of the totality of motions due to forcing on an equatorial beta plane. Initial value problems can also be solved with the aid of the Green's function. Since energy associated with the Rossby gravity mode always travels east, the Green's function can be employed to predict what signal should arrive to the east of a given location if the time history of the fields are known at that position. Various simple analytical examples are discussed. A numerical ocean general circulation model is used to demonstrate the usefulness of the Green's function formalism. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. RP Moore, DW (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. RI MOORE, DENNIS/C-9901-2014 NR 31 TC 8 Z9 8 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1998 VL 103 IS C3 BP 5331 EP 5346 DI 10.1029/97JC02419 PG 16 WC Oceanography SC Oceanography GA ZB957 UT WOS:000072525300001 ER PT J AU Lu, CG Browning, GL AF Lu, CG Browning, GL TI The impact of observational and model errors on four-dimensional variational data assimilation SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID ADJOINT VORTICITY EQUATION; METEOROLOGICAL OBSERVATIONS AB The impact of observational and model errors on four-dimensional variational (4DVAR) data assimilation is analyzed for a general dynamical system. Numerical experiments with both the barotropic vorticity equation and the shallow water system are conducted. It is shown from the analysis and the numerical experiments that when there are random errors in observations or in model parameterizations, the 4DVAR assimilation method can suppress these errors; however when the errors are systematic or biased, the 4DVAR assimilation method tends to either converge to the erroneous observations or introduce the model error into the data analysis, or both. For a multiple-timescale fluid dynamical system, such as the shallow water equations with fluid depth corresponding to the external mode, the skewness in the system can amplify the errors, especially in the fast variable (e.g., the geopotential or height field). Forecasts using the assimilated initial condition with an imperfect model indicate that the forecasts may or may not be improved, depending upon the nature of the model and observational errors, and the length of the assimilation and forecast periods. C1 NOAA, ERL, Forecast Syst Lab, Boulder, CO 80303 USA. Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. RP Lu, CG (reprint author), NOAA, ERL, Forecast Syst Lab, 325 Broadway, Boulder, CO 80303 USA. EM lu@dragon.fsl.noaa.gov NR 21 TC 12 Z9 18 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR 15 PY 1998 VL 55 IS 6 BP 995 EP 1011 DI 10.1175/1520-0469(1998)055<0995:TIOOAM>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZB373 UT WOS:000072465500006 ER PT J AU Woicik, JC AF Woicik, JC TI Random-cluster calculation of bond lengths in strained-semiconductor alloys SO PHYSICAL REVIEW B LA English DT Article ID ABSORPTION FINE-STRUCTURE; SOLID-SOLUTIONS; HETEROSTRUCTURES; LAYERS AB The bond lengths in tetragonally distorted, pseudobinary Ga1-xInxAs alloys on GaAs(001) and GaAs(111) have been calculated within a random-cluster approximation utilizing a valence-force field. For growth on the (001) substrate, the In-As and Ga-As bond lengths are uniformally contracted from their bulk-alloy values by an amount that increases monotonically with x. For growth on the (111) substrate, strain splits the bonds: bonds along [111] are less contracted than bonds along [(1) over bar 1 (1) over bar], [1<(11)over bar>], and [(111) over bar]; however, their average behavior is similar to the (001) case. C1 NIST, Gaithersburg, MD 20899 USA. RP Woicik, JC (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 18 TC 32 Z9 32 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAR 15 PY 1998 VL 57 IS 11 BP 6266 EP 6269 DI 10.1103/PhysRevB.57.6266 PG 4 WC Physics, Condensed Matter SC Physics GA ZD807 UT WOS:000072726400018 ER PT J AU da Costa, CT Nelson, BC Margolis, SA Horton, D AF da Costa, CT Nelson, BC Margolis, SA Horton, D TI Separation of blackcurrant anthocyanins by capillary zone electrophoresis SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE blackcurrant; fruit juices; food analysis; anthocyanins; phenolic compounds ID HIGH-PERFORMANCE LIQUID; FLAVONOID-O-GLYCOSIDES; BORATE COMPLEXATION; ORGANIC-SOLVENTS; CHROMATOGRAPHY; HPLC; JUICE AB The four major anthocyanins present in juice of the blackcurrant (Ribes nigrum) may be completely separated by capillary zone electrophoresis under strongly acidic conditions. The separation, resolution and peak shapes of the anthocyanins are critically influenced by the pH of the running buffer and the presence of an organic solvent. Fused-silica and polyacrylamide-coated capillary columns were evaluated for their ability to resolve the closely migrating analytes. Optimum qualitative separation was achieved on a fused-silica capillary with a phosphate running buffer containing 30% (v/v) acetonitrile at an apparent pH of 1.5. (C) 1998 Elsevier Science B.V. C1 American Univ, Dept Chem, Washington, DC 20016 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Horton, D (reprint author), American Univ, Dept Chem, 4400 Massachusetts Ave, Washington, DC 20016 USA. RI Barrocas Dias, Cristina/S-6824-2016 OI Barrocas Dias, Cristina/0000-0002-1707-2209 NR 23 TC 43 Z9 44 U1 3 U2 19 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 MAR 13 PY 1998 VL 799 IS 1-2 BP 321 EP 327 DI 10.1016/S0021-9673(97)01043-1 PG 7 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA ZD766 UT WOS:000072721600031 ER PT J AU Kulcke, A Blackmon, B Chapman, WB Kim, IK Nesbitt, DJ AF Kulcke, A Blackmon, B Chapman, WB Kim, IK Nesbitt, DJ TI Time-resolved O-3 chemical chain reaction kinetics via high-resolution IR laser absorption methods SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TEMPERATURE-DEPENDENCE; RATE CONSTANTS; OZONE; HO2; OH; O(1D); H2O; PHOTOLYSIS; RADICALS; N-2 AB Excimer laser photolysis in combination with time-resolved IR laser absorption detection of OH radicals has been used to study O-3/OH(v = 0)/HO2 chain reaction kinetics at 298 K, (i.e., OH + O-3 -->(k1) HO2 + O-2 and HO2 + O-3 -->(k2) OH + 2O(2)). From time-resolved detection of OH radicals with high-resolution near IR laser absorption methods, the chain induction kinetics have been measured at up to an order of magnitude higher ozone concentrations ([O-3] less than or equal to 10(17) molecules/cm(3)) than accessible in previous studies. This greater dynamic range permits the full evolution of the chain induction, propagation, and termination process to be temporally isolated and measured in real time. An exact solution for time-dependent OH evolution under pseudo-first-order chain reaction conditions is presented, which correctly predicts new kinetic signatures not included in previous OH + O-3 kinetic analyses. Specifically, the solutions predict an initial exponential loss (chain "induction") of the OH radical to a steady-state level ([OH](ss)), with this fast initial decay determined by the slim of both chain rate constants, k(ind) = k(1) + k(2). By monitoring the chain induction feature, this sum of the rate constants is determined to be k(ind) = 8.4(8) x 10(-14) cm(3) molecule(-1) s(-1) for room temperature reagents. This is significantly higher than the values currently recommended for use in atmospheric models, but in excellent agreement with previous results from Ravishankara et al. [J. Chem. Phys. 1979, 70, 984]. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Nesbitt, DJ (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 42 TC 4 Z9 4 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 12 PY 1998 VL 102 IS 11 BP 1965 EP 1972 DI 10.1021/jp972486k PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZC830 UT WOS:000072622400012 ER PT J AU Sobolewski, MA AF Sobolewski, MA TI Measuring the ion current in electrical discharges using radio-frequency current and voltage measurements SO APPLIED PHYSICS LETTERS LA English DT Article ID RADIOFREQUENCY DISCHARGES; REFERENCE CELL; ELECTRODE; ENERGY; FLUX AB This letter describes a technique for measuring the ion current at a semiconductor wafer that is undergoing plasma processing. The technique relies on external measurements of the radio-frequency (rf) current and voltage at the wafer electrode. The rf signals are generated by the rf bias power which is normally applied to wafers during processing. There is no need for any probe inserted into the plasma or for any additional power supplies which might perturb the plasma. To test the technique, comparisons were made with de measurements of ion current at a bare aluminum electrode, for argon discharges at 1.33 Pa, ion current densities of 1.3-13 mA/cm(2), rf bias frequencies of 0.1-10 MHz, and rf bias voltages from 1 to 200 V. Additional tests showed that ion current measurements could be obtained by the rf technique even when electrically insulating wafers were placed on the electrode and when an insulating layer was deposited on the electrode. [S0003-6951(98)03010-1]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sobolewski, MA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 13 TC 29 Z9 29 U1 0 U2 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 9 PY 1998 VL 72 IS 10 BP 1146 EP 1148 DI 10.1063/1.121032 PG 3 WC Physics, Applied SC Physics GA ZA514 UT WOS:000072370900006 ER PT J AU Berkeland, DJ Miller, JD Bergquist, JC Itano, WM Wineland, DJ AF Berkeland, DJ Miller, JD Bergquist, JC Itano, WM Wineland, DJ TI Laser-cooled mercury ion frequency standard SO PHYSICAL REVIEW LETTERS LA English DT Article ID STATES AB A stable and accurate frequency standard based on the 40.5 GHz ground-state hyperfine transition in Hg-199(+) ions is described. The ions are confined in a cryogenic linear Paul (rf) trap and laser cooled to form a linear crystal. With seven ions and a Ramsey interrogation time of 100 s, the fractional frequency stability is 3.3 (2) x 10(-13)tau(-1/2) for measurement times tau < 2 h. The ground-state hyperfine interval is measured to be 40 507 347 996.841 59 (14) (41) Hz, where the first number in the parentheses is the uncertainty due to statistical and systematic effects, and the second is the uncertainty in the frequency of the time scale to which our standard is compared. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Berkeland, DJ (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 30 TC 147 Z9 148 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 9 PY 1998 VL 80 IS 10 BP 2089 EP 2092 DI 10.1103/PhysRevLett.80.2089 PG 4 WC Physics, Multidisciplinary SC Physics GA ZA636 UT WOS:000072385400016 ER PT J AU Faeder, J Parson, R AF Faeder, J Parson, R TI Ultrafast reaction dynamics in cluster ions: Simulation of the transient photoelectron spectrum of I2-Arn photodissociation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID KINETIC-ENERGY SPECTROSCOPY; MOLECULAR-DYNAMICS; RECOMBINATION DYNAMICS; GEMINATE RECOMBINATION; QUANTUM DECOHERENCE; EXCITED-STATES; I-2; ANION; PHOTOFRAGMENTATION; TRANSITIONS AB Combining an effective Hamiltonian model of electronic structure with nonadiabatic molecular dynamics simulations, we calculate the recently measured transient photoelectron spectrum of I-2(-) dissociated inside a cluster of argon atoms. We find good agreement between calculated and experimental spectra. The transient spectral shifts reflect the dynamics of both the I-2(-) and argon degrees of freedom, revealing pathways and time scales for dissociation, recombination, and vibrational relaxation. (C) 1998 American Institute of Physics. [S0021-9606(98)03010-4]. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Parson, R (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 36 TC 44 Z9 44 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 8 PY 1998 VL 108 IS 10 BP 3909 EP 3914 DI 10.1063/1.475793 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZA530 UT WOS:000072373500009 ER PT J AU Huang, NE Shen, Z Long, SR Wu, MLC Shih, HH Zheng, QN Yen, NC Tung, CC Liu, HH AF Huang, NE Shen, Z Long, SR Wu, MLC Shih, HH Zheng, QN Yen, NC Tung, CC Liu, HH TI The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE non-stationary time series; nonlinear differential equations; frequency-time spectrum; Hilbert spectral analysis; intrinsic time scale; empirical mode decomposition ID FREQUENCY SIGNAL ANALYSIS; WIGNER DISTRIBUTION; EL-NINO; WAVES; GEOSAT; TOOL; MOTION; OCEAN; FLOW AB A new method for analysing nonlinear and non-stationary data has been developed. The key part of the method is the 'empirical mode decomposition' method with which any complicated data set can be decomposed into a finite and often small number of 'intrinsic mode functions' that admit well-behaved Hilbert transforms. This decomposition method is adaptive, and, therefore, highly efficient. Since the decomposition is based on the local characteristic time scale of the data, it is applicable to nonlinear and non-stationary processes. With the Hilbert transform, the 'instrinic mode functions' yield instantaneous frequencies as functions of time that give sharp identifications of imbedded structures. The final presentation of the results is an energy-frequency-time distribution, designated as the Hilbert spectrum. In this method, the main conceptual innovations are the introduction of 'intrinsic mode functions' based on local properties of the signal, which makes the instantaneous frequency meaningful; and the introduction of the instantaneous frequencies for complicated data sets, which eliminate the need for spurious harmonics to represent nonlinear and non-stationary signals. Examples from the numerical results of the classical nonlinear equation systems and data representing natural phenomena are given to demonstrate the power of this new method. Classical nonlinear system data are especially interesting, for they serve to illustrate the roles played by the nonlinear and non-stationary effects in the energy-frequency-time distribution. C1 NASA, Lab Hydrospher Proc, Oceans & Ice Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. NASA, Lab Hydrospher Proc, Observ Sci Branch, Wallops Flight Facil, Wallops Island, VA 23337 USA. NASA, Atmospheres Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Ocean Serv, NOAA, Silver Spring, MD 20910 USA. Univ Delaware, Coll Marine Studies, Newark, DE 19716 USA. USN, Res Lab, Washington, DC 20375 USA. N Carolina State Univ, Dept Civil Engn, Raleigh, NC 27695 USA. USN, Ctr Surface Warfare, Carderock Div, Bethesda, MD 20084 USA. RP Huang, NE (reprint author), NASA, Lab Hydrospher Proc, Oceans & Ice Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Zheng, Quanan/F-9025-2010; Long, Steven/D-7248-2012 NR 64 TC 6275 Z9 8093 U1 77 U2 551 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 EI 1471-2946 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD MAR 8 PY 1998 VL 454 IS 1971 BP 903 EP 995 PG 93 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZD271 UT WOS:000072668500010 ER PT J AU Moon, CK Mcdonough, WG AF Moon, CK Mcdonough, WG TI Multiple fiber technique for the single fiber fragmentation test SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article ID SHEAR-STRENGTH; MICROBOND METHOD; RESIN INTERFACE; GLASS-FIBER; PULL-OUT; STRESS; EPOXY AB The single fiber fragmentation test has been modified by embedding multiple fibers into matrix resin. During testing, we examined the interfacial shear strengths between the fibers and the matrix. In addition, the time-dependent nature of the fragmentation process was considered. In the fragmentation test, we examined the failure process of two fibers placed far from each other, and we found that the failure profile of the two fibers were similar to the failure profiles from tests done on single fibers. When we examined three fibers, we found that the measured interfacial shear strength values were much greater than the shear strength values from either the single or two fiber tests. However, when we used three fibers, we found it difficult to control the interfiber spacing. Consequently, whenever the interfiber spacing was too small, breaks in one fiber caused breaks in the adjacent fiber. In conclusion, using multiple fibers in a fragmentation test has many merits, such as saving time in testing, ease of comparing the effects of fiber surface treatment, and testing different fibers in the same matrix exposed to the same processing conditions. (C) 1998 John Wiley & Sons, Inc. C1 Pukyong Natl Univ, Dept Mat Sci & Engn, Pusan 608737, South Korea. Natl Inst Stand & Technol, Div Polymer, Composites Grp, Gaithersburg, MD 20877 USA. RP Moon, CK (reprint author), Pukyong Natl Univ, Dept Mat Sci & Engn, Pusan 608737, South Korea. NR 23 TC 13 Z9 14 U1 1 U2 3 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD MAR 7 PY 1998 VL 67 IS 10 BP 1701 EP 1709 DI 10.1002/(SICI)1097-4628(19980307)67:10<1701::AID-APP3>3.0.CO;2-N PG 9 WC Polymer Science SC Polymer Science GA YV238 UT WOS:000071803200003 ER PT J AU Stehr, CM Johnson, LL Myers, MS AF Stehr, CM Johnson, LL Myers, MS TI Hydropic vacuolation in the liver of three species of fish from the US West Coast: lesion description and risk assessment associated with contaminant exposure SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE fish; contaminants; liver disease; hydropic vacuolation; biomarkers; risk assessment ID SOLE PAROPHRYS-VETULUS; FLOUNDER PLEURONECTES-AMERICANUS; WINTER FLOUNDER; ENGLISH SOLE; PUGET-SOUND; HEPATIC-LESIONS; PSEUDOPLEURONECTES-AMERICANUS; BOSTON HARBOR; CHEMICAL CONTAMINANTS; GENYONEMUS-LINEATUS AB Hydropic vacuolation (HydVac) of biliary epithelial cells and hepatocytes is described for 3 species of U.S. West Coast bottom fishes. Risk assessment analyses are also conducted to determine if the prevalence of this lesion increases in association with contaminant exposure and site of capture. The morphology of HydVac in starry flounder Platichthys stellatus, white croaker Genyonemus Lineatus and rock sole Lepidopsetta bilineata was similar to that described in winter flounder Pleuronectes americanus from the U.S. Atlantic Coast, especially in that HydVac most commonly affected biliary epithelial cells. Hydropic vacuolation was the most prevalent liver lesion in starry flounder and white croaker captured from contaminated environments. Risk assessment analyses confirmed that the relative risk for HydVac increased with the presence of aromatic and chlorinated hydrocarbons in sediment, fish bile, and fish Liver for these species. Hydropic vacuolation also frequently occurred in rock sole, but the lesion showed no clear association with contaminant exposure in this species. The types of Liver lesions that were useful biomarkers of contaminant effects in fish depended on the species and this factor must be taken into account when evaluating histopathological biomarkers of response to contaminant exposure. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Stehr, CM (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 48 TC 26 Z9 29 U1 0 U2 1 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 MAR 5 PY 1998 VL 32 IS 2 BP 119 EP 135 DI 10.3354/dao032119 PG 17 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA ZN342 UT WOS:000073636300006 PM 9676252 ER PT J AU Amin, J Aust, JA Veasey, DL Sanford, NA AF Amin, J Aust, JA Veasey, DL Sanford, NA TI Dual wavelength, 980 nm-pumped, Er/Yb-codoped waveguide laser in Ti : LiNbO3 SO ELECTRONICS LETTERS LA English DT Article ID GUIDE AB The authors demonstrate the first Er/Yb codoped waveguide laser in Ti:LiNbO3. The device was fabricated on x-cut LiNbO3 with the guides parallel to the z-axis, resulting in reduced photorefractive damage and allowing 980nm pumping. Laser operation is demonstrated at two wavelengths, in the 1 and the 1.55 mu m regions, corresponding to Yb and Er transitions, respectively. C1 Corning Inc, Corning, NY 14831 USA. Natl Inst Stand & Technol, Optoelect Mfg Grp, Boulder, CO 80303 USA. RP Amin, J (reprint author), Corning Inc, SP-DV-02-5, Corning, NY 14831 USA. NR 10 TC 20 Z9 20 U1 0 U2 5 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD MAR 5 PY 1998 VL 34 IS 5 BP 456 EP 458 DI 10.1049/el:19980267 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA ZD662 UT WOS:000072709800029 ER PT J AU Murphy, DM Anderson, JR Quinn, PK McInnes, LM Brechtel, FJ Kreidenweis, SM Middlebrook, AM Posfai, M Thomson, DS Buseck, PR AF Murphy, DM Anderson, JR Quinn, PK McInnes, LM Brechtel, FJ Kreidenweis, SM Middlebrook, AM Posfai, M Thomson, DS Buseck, PR TI Influence of sea-salt on aerosol radiative properties in the Southern Ocean marine boundary layer SO NATURE LA English DT Article ID CLOUD CONDENSATION NUCLEI; GAS-EXCHANGE; PARTICLES; SULFUR; ATLANTIC; CLIMATE; METHANESULFONATE; AIRCRAFT AB There has been considerable debate about the relative importance of sea-salt and sulphate from non-sea-salt sources in determining aerosol radiative effects in the marine boundary layer In the marine boundary layer, the most numerous aerosols are volatile sulphate particles smaller than about 0.08 mu m (ref. 1) and most of the aerosol mass is in a few sea-salt particles larger than 1 mu m. Yet intermediate-size aerosols between about 0.08 and 1 mu m diameter are the most relevant to the radiative forcing of climate because they efficiently scatter solar radiation and also serve as cloud nuclei(2). Indeed, Charlson et al.(3) hypothesized that oceanic production of sulphate aerosols from the oxidation of dimethyl sulphide could be a powerful feedback in the climate system. It is generally assumed that marine aerosols smaller than about 1 mu m are non-sea-salt sulphate, but a recent review cites indirect evidence that many aerosols in the sub-micrometre range contain at least some sea-salt(4,5), Here we present direct observational evidence from a remote Southern Ocean region that almost all aerosols larger than 0.13 mu m in the marine boundary layer contained sea-salt. These sea-salt aerosols had important radiative effects: they were responsible for the majority of aerosol-scattered light, and comprised a significant fraction of the inferred cloud nuclei. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA. RP Murphy, DM (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Posfai, Mihaly/C-1792-2012; Middlebrook, Ann/E-4831-2011; Murphy, Daniel/J-4357-2012; Quinn, Patricia/R-1493-2016; Kreidenweis, Sonia/E-5993-2011 OI Posfai, Mihaly/0000-0001-9355-3533; Middlebrook, Ann/0000-0002-2984-6304; Murphy, Daniel/0000-0002-8091-7235; Quinn, Patricia/0000-0003-0337-4895; Kreidenweis, Sonia/0000-0002-2561-2914 NR 30 TC 191 Z9 195 U1 6 U2 43 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAR 5 PY 1998 VL 392 IS 6671 BP 62 EP 65 DI 10.1038/32138 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZA528 UT WOS:000072373000048 ER PT J AU Zhao, J Glazounov, AE Zhang, QM Toby, B AF Zhao, J Glazounov, AE Zhang, QM Toby, B TI Neutron diffraction study of electrostrictive coefficients of prototype cubic phase of relaxer ferroelectric PhMg1/3 Nb-2/3 O-3 SO APPLIED PHYSICS LETTERS LA English DT Article ID X-RAY; PB(MG1/3NB2/3)O3; PBMG1/3NB2/3O3; CERAMICS; POLARIZATION; TRANSITION AB The electrostrictive coefficients of prototype cubic phase of PbMg1/3Nb2/3O3 are studied using a high-resolution neutron powder diffraction experiment. The key idea of the approach is to "eliminate" from the material the inhomogeneity related to the presence of the double-phase mixture "polar regions/nonpolar matrix," and to study two structurally homogeneous states: prototype cubic at temperatures above 600 K and rhombohedral ferroelectric at temperatures below 220 K. The obtained value of volumetric electrostrictive coefficient. O-h=(8.3+/-1.0)x10(-2) x(m(4)/C-2), is consistent with those of other perovskite ferroelectrics with a prototype cubic phase. (C) 1998 American Institute of Physics. C1 Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Zhang, QM (reprint author), Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. EM qxzl@psu.edu RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 15 TC 57 Z9 58 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 2 PY 1998 VL 72 IS 9 BP 1048 EP 1050 DI 10.1063/1.120960 PG 3 WC Physics, Applied SC Physics GA YZ775 UT WOS:000072290400017 ER PT J AU Brewczyk, M Clark, CW Lewenstein, M Rzazewski, K AF Brewczyk, M Clark, CW Lewenstein, M Rzazewski, K TI Stepwise explosion of atomic clusters induced by a strong laser field SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY-EMISSION; IONIZATION; GENERATION; PULSES; KR AB We present numerical simulations of a small Xe cluster exposed to strong laser pulses. Prompt ionization and fast acceleration of cluster electrons are followed by an explosion of the cluster ions. The explosion exhibits a shell structure, in which layers of cluster ions are expelled sequentially; the first ions expelled have kinetic energies T-max much higher than those encountered in Coulomb explosions of small molecules. These high energies are produced by the Coulomb energy of the original assembly of cluster ions, and by effective transfer of hot-electron energy to outer layers of the cluster. For laser intensities of 10(15) W/cm(2), T-max approximate to 1 keV for Xe-10 clusters. C1 Filia Uniwersytetu Warszawskiego, PL-15424 Bialystok, Poland. US Dept Commerce, Div Electron & Opt Phys, Phys Lab, Natl Inst Stand & Technol,Technol Adm, Gaithersburg, MD 20899 USA. Ctr Etud Saclay, CEA, Serv Photons Atomes & Mol, F-91191 Gif Sur Yvette, France. PAN, Centrum Fizyki Teoretucznej, PL-02668 Warsaw, Poland. Coll Sci, PL-02668 Warsaw, Poland. RP Brewczyk, M (reprint author), Filia Uniwersytetu Warszawskiego, Lipowa 41, PL-15424 Bialystok, Poland. RI Clark, Charles/A-8594-2009; Rzazewski, Kazimierz/G-4854-2011; Lewenstein, Maciej/I-1337-2014 OI Clark, Charles/0000-0001-8724-9885; Rzazewski, Kazimierz/0000-0002-6082-3565; Lewenstein, Maciej/0000-0002-0210-7800 NR 24 TC 42 Z9 42 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 2 PY 1998 VL 80 IS 9 BP 1857 EP 1860 DI 10.1103/PhysRevLett.80.1857 PG 4 WC Physics, Multidisciplinary SC Physics GA YZ785 UT WOS:000072291400017 ER PT J AU Leo, PJ Mullamphy, DFT Peach, G Venturi, V Whittingham, IB AF Leo, PJ Mullamphy, DFT Peach, G Venturi, V Whittingham, IB TI Temperature dependence of the self-broadened 540.06 nm neon line SO ACTA PHYSICA POLONICA A LA English DT Article ID CLOSE-COUPLED CALCULATION AB Quantum close-coupled calculations of the collisional self-broadening of the 540.06 nm neon line (3s[3/2](1) - 3p'[1/2](0)) are presented for temperatures from 70 K to 900 K. These calculations are based on the quantum-mechanical impact theory of Baranger and represent the interatomic interaction by adiabatic molecular potentials: calculated using model potentials for the electron atom and atomic core-core interactions. The calculated widths and shifts vary smoothly with temperature and are accurately given across the temperature range by fourth order polynomial fits. C1 UCL, Dept Phys & Astron, London WC1E 6BT, England. James Cook Univ N Queensland, Sch Comp Sci Math & Phys, Townsville, Qld 4811, Australia. RP Leo, PJ (reprint author), Natl Inst Stand & Technol, Atom Phys Div, PHYS A267, Gaithersburg, MD 20899 USA. RI Leo, Paul/B-3470-2011 OI Leo, Paul/0000-0001-8325-4134 NR 9 TC 2 Z9 2 U1 0 U2 2 PU POLISH ACAD SCIENCES INST PHYSICS PI WARSAW PA AL LOTNIKOW 32-46, PL-02-668 WARSAW, POLAND SN 0587-4246 J9 ACTA PHYS POL A JI Acta Phys. Pol. A PD MAR PY 1998 VL 93 IS 3 BP 459 EP 464 PG 6 WC Physics, Multidisciplinary SC Physics GA ZK955 UT WOS:000073384400002 ER PT J AU Baldocchi, D Meyers, T AF Baldocchi, D Meyers, T TI On using eco-physiological, micrometeorological and biogeochemical theory to evaluate carbon dioxide, water vapor and trace gas fluxes over vegetation: a perspective SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Review DE biosphere-atmosphere interactions; trace gas fluxes; Eddy covariance measurements; evaporation; carbon dioxide; biogeochemistry ID NET PRIMARY PRODUCTION; LEAF-AREA INDEX; GASEOUS DRY DEPOSITION; LAND SURFACE PROCESSES; SIMPLE BIOSPHERE MODEL; STOMATAL CONDUCTANCE; NITROGEN NUTRITION; DECIDUOUS FOREST; SOIL RESPIRATION; TEMPERATURE-DEPENDENCE AB How eco-physiological, biogeochemical and micrometeorological theory can be used to compute biosphere-atmosphere, trace gas exchange rates is discussed within the framework of a process model. The accuracy of the theory is tested by comparing computations of mass and energy flux densities (water vapor, sensible heat, CO2 and ozone) against eddy covariance measurements over five distinct canopies (wheat, potato and soybean crops and a temperate broad-leaved and a boreal conifer forest). Once tested, the theory is used to evaluate how interactions between climate and vegetation might influence leaf area and photosynthetic capacity and, in turn, alter energy balance partitioning and the transfer rates of CO2 and other trace eases over vegetation canopies, Model parameters, derived from biogeochemical and eco-physiological, principles, enabled the model to estimate rates of mass and energy exchange with reasonable fidelity. In particular, the theory reproduced the magnitudes and distinct diurnal patterns associated with mass and energy fluxes over a spectrum of vegetation types. Model sensitivity tests revealed that variations in leaf area index and photosynthetic capacity interacted to increase rates of evaporation and carbon dioxide and pollutant uptake, greatly, and in a curvilinear manner. Finally, we conclude that the assignment of many model parameters according to plant functional type has much potential for use in global and regional scale ecosystem, climate and biogeochemistry models. Published by Elsevier Science B.V. C1 NOAA, Air Resources Lab, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. RP Baldocchi, D (reprint author), NOAA, Air Resources Lab, Atmospher Turbulence & Diffus Div, POB 2456, Oak Ridge, TN 37831 USA. EM baldocchi@atdd.noaa.gov RI Baldocchi, Dennis/A-1625-2009; Meyers, Tilden/C-6633-2016 OI Baldocchi, Dennis/0000-0003-3496-4919; NR 133 TC 276 Z9 292 U1 7 U2 67 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 PY 1998 VL 90 IS 1-2 BP 1 EP 25 DI 10.1016/S0168-1923(97)00072-5 PG 25 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA ZK358 UT WOS:000073312400002 ER PT J AU Dryer, M AF Dryer, M TI Multidimensional, magnetohydrodynamic simulation of solar-generated disturbances: Space weather forecasting of geomagnetic storms SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 28th Plasmadynamics and Lasers Conference CY JUN 23-25, 1997 CL ATLANTA, GEORGIA SP Amer Inst Aeronaut & Astronaut ID INTERPLANETARY SHOCK-WAVES; EULERIAN FICE SCHEME; BOUNDARY-CONDITIONS; MHD FLOWS; EVOLUTION AB A short review is given, first, of an extension of classical, continuum gasdynamics to solar system magnetohydrodynamics (MHD) in both the steady and time-dependent contexts. A slightly longer review is given of two- and three-dimensional, numerical, MHD simulations of transient, solar-generated disturbances in the inner solar system. Validation of this approach is provided by making use of several examples wherein shock shapes and energetic particle fluxes (generated by shocks) are empirically confirmed. Although these studies are based on an ideal, one-fluid (proton) plasma, we suggest that a three-dimensional MHD model be employed to make use of presently available solar observations as approximate physical parameters for initialization conditions. Such a model may be useful, within the space weather national implementation plan, for geomagnetic storm forecasts. C1 NOAA, Space Environm Ctr, Environm Res Labs, Boulder, CO 80303 USA. RP Dryer, M (reprint author), NOAA, Space Environm Ctr, Environm Res Labs, 325 Broadway, Boulder, CO 80303 USA. NR 33 TC 34 Z9 34 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD MAR PY 1998 VL 36 IS 3 BP 365 EP 370 DI 10.2514/2.405 PG 6 WC Engineering, Aerospace SC Engineering GA YZ480 UT WOS:000072258300009 ER PT J AU Krahn, MM Stein, JE AF Krahn, MM Stein, JE TI Assessing exposure of marine biota and habitats to petroleum compounds SO ANALYTICAL CHEMISTRY LA English DT Article ID VALDEZ OIL-SPILL; EXXON-VALDEZ; AROMATIC-COMPOUNDS; SUBTIDAL SEDIMENTS; FISH; BILE C1 NOAA, Div Environm Technol & Assessment, Environm Conservat Div,NW Fisheries Ctr, Natl Marine Fisheries Serv, Seattle, WA 98112 USA. RP Krahn, MM (reprint author), NOAA, Div Environm Technol & Assessment, Environm Conservat Div,NW Fisheries Ctr, Natl Marine Fisheries Serv, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 17 TC 9 Z9 9 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAR 1 PY 1998 VL 70 IS 5 BP 186A EP 192A PG 7 WC Chemistry, Analytical SC Chemistry GA ZB216 UT WOS:000072448400004 ER PT J AU Fayer, R Graczyk, TK Lewis, EJ Trout, JM Farley, CA AF Fayer, R Graczyk, TK Lewis, EJ Trout, JM Farley, CA TI Survival of infectious Cryptosporidium parvum oocysts in seawater and Eastern oysters (Crassostrea virginica) in the Chesapeake Bay SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID MARINE WATERS; BOVINE AB Oocysts of Cryptosporidium parvum placed in artificial seawater at salinities of 10, 20, and 30 ppt at 10 degrees C and at 10 ppt at 20 degrees C were infectious after 12 weeks, Those placed in seawater at 20 ppt and 30 ppt at 20 degrees C were infectious for 8 and 4 weeks, respectively, These findings suggested that oocysts could survive in estuarine waters long enough to be removed by filter feeders such as oysters, Thereafter, 30 Eastern oysters, Crassostrea virginica, were collected,vith a dredge or with hand tongs at each of six sites within Maryland tributaries of the Chesapeake Bay in May and June and in August and September of 1997, Hemocytes and gill washings from all oysters were examined for the presence of Cryptosporidium oocysts and Giardia cysts by immunofluorescence microscopy utilizing a commercially available kit containing fluorescein isothiocyanate-conjugated monoclonal antibodies, Giardia was not detected by this method from any of the 360 oysters examined, Presumptive identification of Cryptosporidium oocysts was made in either hemocytes or gill washings of oysters from all six sites both times that surveys were conducted, In addition, during August and September, for each of the six sites, hemocytes from the 30 oysters were pooled and gill washings from the oysters were pooled, Each pool was delivered by gastric intubation to a litter of neonatal mice to produce a bioassay for oocyst infectivity, Intestinal tissue from two of three mice that received gill washings from oysters collected at a site near a large cattle farm and shoreline homes with septic tanks was positive for developmental stages of C. parvum, These findings demonstrate for the first time that oysters in natural waters harbor infectious C. parvum oocysts and can serve as mechanical vectors of this pathogen. C1 ARS, Immunol & Dis Resistance Lab, USDA, Beltsville, MD 20705 USA. Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Mol Microbiol & Immunol, Baltimore, MD 21205 USA. Natl Marine Fisheries Serv, Cooperat Oxford Lab, Natl Ocean & Atmospher Adm, Oxford, MD 21654 USA. RP Fayer, R (reprint author), ARS, Immunol & Dis Resistance Lab, USDA, 10300 Baltimore Ave,Bldg 1040, Beltsville, MD 20705 USA. NR 17 TC 98 Z9 104 U1 2 U2 7 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD MAR PY 1998 VL 64 IS 3 BP 1070 EP 1074 PG 5 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA YZ798 UT WOS:000072292700040 PM 9501446 ER PT J AU Dummer, DJ Kaplan, SG Hanssen, LM Pine, AS Zong, YG AF Dummer, DJ Kaplan, SG Hanssen, LM Pine, AS Zong, YG TI High-quality Brewster's angle polarizer for broadband infrared application SO APPLIED OPTICS LA English DT Article AB We have designed and constructed a linear polarizer for use with visible and infrared radiation. The broadband polarizer consists of four germanium plates arranged In st chevron geometry. Input radiation is incident near Brewster's angle for the first plate such that the reflected beam is preferentially s-wave polarized. This reflected beam is steered subsequently to the successive plates, always intersecting near Brewster's angle. The beam polarization at the output of the device is almost completely s-wave polarized. The ratio of the the paraxial flux of the nearly extinguished p-wave polarized light to the s-wave polarized light transmitted through the device is found to be less than 10(-5) for laser illumination at wavelengths af 0.638, 1.32, 3.39, and 10.6 mu m. Calculations predict that extinction ratios less than 10(-5) are achievable over the wavelength range from 0.4 mu m to beyond 500 mu m. Alternative design geometries involving fewer plates are also described along with their advantages and disadvantages. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Dummer, DJ (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 20 TC 17 Z9 17 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAR 1 PY 1998 VL 37 IS 7 BP 1194 EP 1204 DI 10.1364/AO.37.001194 PG 11 WC Optics SC Optics GA YY886 UT WOS:000072197000010 PM 18268704 ER PT J AU Pierce, DT Davies, A Stroscio, JA Celotta, RJ AF Pierce, DT Davies, A Stroscio, JA Celotta, RJ TI Polarized light emission from the metal-metal STM junction SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article; Proceedings Paper CT 9th International Conference on Scanning Tunneling Microscopy/Spectroscopy and Related Techniques CY JUL 20-25, 1997 CL HAMBURG, GERMANY SP Free & Hanseat City Hamburg, German Min Educ Sci Res & Technol, German Sci Fdn, Commiss European Communities, Oxford Instruments GmbH, Omicron Vakuumphys GmbH, Topometrix GmbH, Digital Instruments ID SCANNING-TUNNELING-MICROSCOPE; CIRCULAR-DICHROISM AB The polarization of light emitted during inelastic tunneling of electrons into both Au(111) and Fe(001) using W(111) tips in an STM junction has been fully characterized by measuring the Stokes parameters. The emitted light for both Au(111) and Fe(001) is fully polarized; it is predominantly linearly polarized in the plane formed by the tip axis and direction of light emission. For both samples, there is a small circular polarization which is tip-dependent and can be attributed to tip asymmetries. No magnetization-dependent circular polarization was observed for Fe(001). C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Pierce, DT (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 14 TC 14 Z9 14 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD MAR PY 1998 VL 66 SU S BP S403 EP S406 DI 10.1007/s003390051172 PN 1 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 136YQ UT WOS:000076887000085 ER PT J AU Murtz, M Wells, JS Hollberg, L Zibrova, T Mackie, N AF Murtz, M Wells, JS Hollberg, L Zibrova, T Mackie, N TI Extended-cavity grating-tuned operation of mid-infrared InAsSb diode lasers SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID MU-M AB Novel InAsSb diode lasers have been operated in an extended-cavity grating-tuned configuration. These devices operate near liquid-nitrogen temperature and emit laser light in the spectral region near lambda = 3 mu m. We have developed a LN2 cryostat that permits placement of both the collimation optics and the extended-cavity elements within a vacuum chamber. We have observed tuning of the laser frequency over a 1.44 THz (48 cm(-1)) range by rotation of the external grating. This result was obtained without anti-reflection coating of the laser output facet. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Murtz, M (reprint author), Univ Bonn, Inst Angew Phys, Wegelerstr 8, D-53115 Bonn, Germany. NR 12 TC 2 Z9 2 U1 0 U2 2 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 MAR PY 1998 VL 66 IS 3 BP 277 EP 281 DI 10.1007/s003400050389 PG 5 WC Optics; Physics, Applied SC Optics; Physics GA ZB171 UT WOS:000072443500003 ER PT J AU Baeverfjord, G Asgard, T Shearer, KD AF Baeverfjord, G. Asgard, T. Shearer, K. D. TI Development and detection of phosphorus deficiency in Atlantic salmon, Salmo salar L., parr and post-smolts SO AQUACULTURE NUTRITION LA English DT Article DE deficiency; bone pathology; mineral requirements; mineral retention; phosphorus AB A pathological condition was induced in Atlantic salmon, Salmo salar L., by feeding a diet severely deficient in phosphorus. Parallel results were obtained in two consecutive experiments, one in fresh water and one in sea water. The deficiency condition was first manifest as a reduction in whole-body calcium (Ca) and phosphorus (P) levels and the development of abnormally soft and malformed bones. In later stages, growth was severely impaired and there was elevated mortality compared with fish fed a diet with sufficient phosphorus. Two semipurified casein-based test diets were used in the experiments. The low-P diet contained only the P from casein, 3.5 g kg(-1) or 0.35%, whereas the reference diet was supplemented with P and contained 9.0 g kg(-1) or 0.9%. The diets were fed to salmon parr in fresh water (initial weight 4.7 g) and to post-smolts in sea water (initial weight 113 g) for 12 and 15 weeks, respectively. In both experiments, the fish grew adequately for a prolonged period, whereas the whole-body Ca and P levels declined almost immediately. Within a few weeks, the whole-body P content was reduced to approximate to 65% of the initial value, and Ca to 40%. The reductions in mineral content were most severe in the mineral-rich tissues, bones and scales. On gross examination, all bony structures were abnormally soft. The ribs were wrinkly, and the spine displayed scoliotic changes. These changes were correlated to the reduction in bone mineralization, and were manifest at the time when reductions in growth rate could be noted. After the deficient fish were fed adequate levels of P for 9 weeks, their whole-body mineral levels returned to normal. The bone lesions did not heal completely during the same period of time. C1 [Baeverfjord, G.; Asgard, T.] Inst Aquaculture Res AKVAFORSK, N-6601 Sunndalsora, Norway. [Shearer, K. D.] NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Baeverfjord, G (reprint author), Inst Aquaculture Res AKVAFORSK, N-6601 Sunndalsora, Norway. EM grete.baverfjord@akvaforsk.nlh.no FU Norwegian Research Council through the 'Salmonid' programme FX Funding for this study was provided by The Norwegian Research Council through the 'Salmonid' programme. We wish to thank Asbjorn Bakken and Arild Linseth of AKVAFORSK for skilful management of the experiments, and Bjorn Brenna, Department of Agricultural Engineering, Agricultural University of Norway, for carrying out the Instron (R) measurements. We also thank Dr R.W. Hardy of NFSC for helpful comments on the manuscript. NR 46 TC 99 Z9 118 U1 5 U2 22 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1353-5773 J9 AQUACULT NUTR JI Aquac. Nutr. PD MAR PY 1998 VL 4 IS 1 BP 1 EP 11 DI 10.1046/j.1365-2095.1998.00095.x PG 11 WC Fisheries SC Fisheries GA V27FL UT WOS:000208599000001 ER PT J AU Rukhovets, L van den Dool, HM Barnston, AG AF Rukhovets, L van den Dool, HM Barnston, AG TI Forecast-observation pattern relationships in NCEP medium range forecasts of non-winter Northern Hemisphere 500-mb height fields SO ATMOSPHERE-OCEAN LA English DT Article ID CIRCULATION PATTERNS; SKILL AB Empirical orthogonal function (EOF) and singular value decomposition (SVD) analyses are applied to the Dynamical Extended Range Forecasting 90 (DERF90) dataset to find the most predictable areas and patterns in the non-winter Northern Hemisphere 500-mb height fields. Global 500-mb height forecast and analysis fields covering 4 months of 1990 are used The EOF method is applied to the forecast and analysis fields separately A close correspondence between the forecast and analysis modes is found for 1-day lead time. The correlation relations between these modes rapidly decrease with increasing forecast lead time. At 10-day lead the projections of the forecasts and corresponding analyses onto the strongest Northern Hemisphere EOF mode of the analyses correlate at 0.65, which is which higher than the general forecast-analysis correlation of about 0.20. This particularly predictable mode consists of a Pacific/North America-like pattern. Joint forecast vs. analysis correlation matrices were used to apply the SVD method to forecast and analysis fields. By design, the correlations between the forecast and analysis SVD modes are stronger than between the forecast and analysis EOF modes. Maps of temporal correlations between gridpoint values of analysis fields and the first and second EOF as well as SVD expansion coefficients of the forecast fields (i.e., heterogeneous EOF and SVD correlation maps) are used to find the regions of the best prediction skill. It is shown that the Pacific/North American, western and southeastern Pacific the southern Atlantic and Indian ocean areas have relatively better prediction skill. C1 NOAA, NCEP, Climate Predict Ctr, Washington, DC 20233 USA. RP Rukhovets, L (reprint author), NASA, Goddard Space Flight Ctr, 7501 Forbes Blvd,Suite 200, Seabrook, MD 20706 USA. NR 17 TC 0 Z9 0 U1 1 U2 2 PU CANADIAN METEOROLOGICAL OCEANOGRAPHIC SOC PI OTTAWA PA 150 LOUIS PASTEUR PVT., STE 112, MCDONALD BUILDING, OTTAWA, ONTARIO K1N 6N5, CANADA SN 0705-5900 J9 ATMOS OCEAN JI Atmos.-Ocean PD MAR PY 1998 VL 36 IS 1 BP 55 EP 70 PG 16 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA ZE287 UT WOS:000072776900004 ER PT J AU Lindberg, SE Hanson, PJ Meyers, TP Kim, KH AF Lindberg, SE Hanson, PJ Meyers, TP Kim, KH TI Air/surface exchange of mercury vapor over forests - The need for a reassessment of continental biogenic emissions SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT 4th International Conference on Mercury as a Global Pollutant CY AUG 04-08, 1996 CL HAMBURG, GERMANY SP Aluminium Co Amer (ALCOA), BSL Olefinverbund GMBH, City Hamburg, Deutsch Forschungsgemeinsch, Elect Power Res Inst, Environm Canada, AES, European Commiss, SM&T, Florida Dept Environm Protect, Frontier Geosci, USA, GKSS Res Ctr, Hlth Canada, MSB, Oak Ridge Natl Lab, US DOE, US EPA, Verein Freunde Forderer GKSS DE micrometeorological studies; atmosphere/surface exchange processes; emission; dry deposition; biogeochemical cycling; modeling; trace metals; air toxics; boreal forest; Sweden ID ELEMENTAL MERCURY; VOLATILE MERCURY; SURFACE EXCHANGE; TRACE-METALS; PHASE; SOILS; DEPOSITION; FLUXES; AIR; ATMOSPHERE AB Atmospheric sources are significant in the cycling of Hg in the biosphere, but there are few reliable data on air:surface exchange of Hg in terrestrial systems. We developed a tower-based micrometeorological gradient method for measuring gas-phase Hg(o) fluxes over soils and vegetation. We describe here results of the modified Bowen ratio approach from three separate flux sampling campaigns: over a mature deciduous forest at the Walker Branch Watershed in Tennessee, over a young pine plantation in Tennessee, and over the boreal forest floor at the Lake Gordsjon watershed in Sweden. Our data show that Hg(o) exchange over these surfaces is bidirectional, but is primarily characterized by emissions from plants and soil. Dry deposition (foliar uptake) is less frequent, of generally lower magnitude, and may be enhanced by surface wetness. We measured emissions over tree canopies in Tennessee in the range of similar to 10-300 ng m(-2) h(-1), and over the boreal forest floor in Sweden of similar to 1-4 ng m(-2) h(-1). Fluxes were influenced by temperature, solar radiation, and atmospheric turbulence. The ability of trees to emit Hg from soil pools has now been established. Others have proposed a significant biotic re-emission of Hg(o) from the oceans, and our data provide the first direct evidence of a similar process in terrestrial systems. These data have been combined with results from chamber studies to estimate the overall flux of gas-phase Hg(o) between the atmosphere and terrestrial systems. Transpiration of Hg(o) represents a previously unmeasured mobilization of Hg from the continents to the troposphere. Including this new source term could increase current estimates of so-called natural emissions by over 100%. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. NOAA, Atmospher Turbulence Diffus Lab, ERL, Oak Ridge, TN USA. Sang Ji Univ, Wonju, South Korea. RP Lindberg, SE (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Hanson, Paul J./D-8069-2011; Meyers, Tilden/C-6633-2016 OI Hanson, Paul J./0000-0001-7293-3561; NR 52 TC 175 Z9 191 U1 5 U2 41 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 MAR PY 1998 VL 32 IS 5 BP 895 EP 908 DI 10.1016/S1352-2310(97)00173-8 PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZK565 UT WOS:000073337900010 ER PT J AU Pirrone, N Allegrini I Keeler, GJ Nriagu, JO Rossmann, R Robbins, JA AF Pirrone, N Allegrini, I Keeler, GJ Nriagu, JO Rossmann, R Robbins, JA TI Historical atmospheric mercury emissions and depositions in North America compared to mercury accumulations in sedimentary records SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT 4th International Conference on Mercury as a Global Pollutant CY AUG 04-08, 1996 CL HAMBURG, GERMANY SP Aluminium Co Amer (ALCOA), BSL Olefinverbund GMBH, City Hamburg, Deutsch Forschungsgemeinsch, Elect Power Res Inst, Environm Canada, AES, European Commiss, SM&T, Florida Dept Environm Protect, Frontier Geosci, USA, GKSS Res Ctr, Hlth Canada, MSB, Oak Ridge Natl Lab, US DOE, US EPA, Verein Freunde Forderer GKSS DE mercury; atmospheric emission; atmospheric deposition; gold and silver mining; industrial source; sediment; Great Lakes; North America ID LAKE-ONTARIO; ANTHROPOGENIC INFLUENCES; POWER-PLANTS; TRACE-METALS; GREAT-LAKES; ST-CLAIR; POLLUTION; FLUXES; TRANSPORT; EXCHANGE AB Gold and silver production in North America (included United States, Canada and Mexico) released a large amount of mercury to the atmosphere until well into this century when mercury (Hg) amalgamation was replaced by cyanide concentration. Since then, emissions from industries have been the dominant anthropogenic sources of atmospheric Hg in North America as a whole. Past Hg emissions from gold and silver extractions in North America during the 1800s do not show a clear evidence of atmospheric deposition occurred at the coring sites considered in this study. Estimated atmospheric emissions of Hg in North America peaked in 1879 (at about 1708 t yr(-1)) and 1920 (at about 940 t yr(-1)), primarily due to Hg emissions from gold and silver mining. After the Great Economic Depression (1929) Hg emissions peaked again in the 1947 (274 t yr(-1)), in 1970 (325 t yr(-1)) and in 1989 (330 t yr(-1)) as result of increased Hg emissions from industrial sources, though improvements in the emissions control technology in United States and Canada have been substantial. Estimates of total atmospheric deposition fluxes of Hg to water and terrestrial receptors were in the range of 14.3-19.8 mu g m(-2) yr(-1) in North America as a whole, and averaged 135 mu g m(-2) yr(-1) (global background + local emissions) in the Great Lakes. These values were in good agreement with recent estimates reported in literature. The comparison of atmospheric Hg deposition fluxes with Hg accumulation rates in sediment cores suggests that atmospheric deposition was the major source of Hg entering the lakes system at coring sites, however, important contributions to Lake Ontario sediment cores sites from 1940 to 1970 were likely originated from local point sources (i.e. direct discharges). (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calabria, CNR, Inst Atmospher Pollut, DEIS, I-87036 Arcavacata Di Rende, Italy. CNR, Inst Atmospher Pollut, I-00016 Monterotondo, Italy. Univ Michigan, Dept Environm & Ind Hlth, Ann Arbor, MI 48109 USA. US EPA, Midcontinent Ecol Div, Large Lakes Res Stn, Grosse Ile, MI 48138 USA. NOAA, Great Lakes Environm Res Lab, US Dept Commerce, Ann Arbor, MI 48105 USA. RP Pirrone, N (reprint author), Univ Calabria, CNR, Inst Atmospher Pollut, DEIS, I-87036 Arcavacata Di Rende, Italy. NR 74 TC 123 Z9 127 U1 4 U2 33 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 MAR PY 1998 VL 32 IS 5 BP 929 EP 940 DI 10.1016/S1352-2310(97)00353-1 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZK565 UT WOS:000073337900013 ER PT J AU Siegel, W Migdalek, J Kim, YK AF Siegel, W Migdalek, J Kim, YK TI Dirac-Fock oscillator strengths for E1 transitions in the sodium isoelectronic sequence (Na I-Ca X) SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID MULTICONFIGURATION HARTREE-FOCK; RESOLVED LASER SPECTROSCOPY; LIFETIME MEASUREMENTS; BEAM-FOIL; COULOMB-APPROXIMATION; RESONANCE TRANSITIONS; ELECTRIC-DIPOLE; MG-II; IONS; PROBABILITIES AB Electric dipole transition oscillator strengths have been computed for low-lying transitions in the sodium isoelectronic sequence (Na I through Ca X) as well as for principal series in neutral sodium up to n = 24. The single-configuration Dirac-Fock method has been used. The core-valence electron correlation has been treated within the core polarization model and its importance to oscillator strength calculations is carefully studied. (C) 1998 Academic Press. C1 Cracow Pedag Univ, Inst Phys & Comp Sci, PL-30084 Krakow, Poland. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Siegel, W (reprint author), Cracow Pedag Univ, Inst Phys & Comp Sci, PL-30084 Krakow, Poland. NR 40 TC 18 Z9 19 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0092-640X EI 1090-2090 J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD MAR PY 1998 VL 68 IS 2 BP 303 EP 322 DI 10.1006/adnd.1997.0769 PG 20 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA ZK058 UT WOS:000073280700006 ER PT J AU Borg, B Antonopoulou, E Mayer, I Andersson, E Berglund, I Swanson, P AF Borg, B Antonopoulou, E Mayer, I Andersson, E Berglund, I Swanson, P TI Effects of gonadectomy and androgen treatments on pituitary and plasma levels of gonadotropins in mature male Atlantic salmon, Salmo salar, parr-positive feedback control of both gonadotropins SO BIOLOGY OF REPRODUCTION LA English DT Article ID MALE MASU SALMON; RAINBOW-TROUT; GTH-II; HORMONE ACCUMULATION; REPRODUCTIVE-CYCLE; ONCORHYNCHUS-MASOU; BALTIC SALMON; COHO SALMON; 5 ANDROGENS; IMMATURE AB The aim of the present study was to clarify the role of feedback control on the (brain)-pituitary-gonadal axis in regulating FSH (gonadotropic hormone, GTH I) and LH (GTH II) in natural maturation in salmonids. In two experiments, 2-yr-old previously mature Atlantic salmon male parr were castrated or sham operated in the spring following their first reproductive season. In one of the experiments, castrated fish were also implanted with silicone elastomer capsules containing testosterone (T) or 11-ketoandrostenedione (11KA). The fish were sampled in July, September, and November (spawning period). Pituitary and plasma LH and FSH levels were measured using RIA and were lower in castrated than in sham-operated fish, indicating positive feedback on both FSH and LH. T, and to a lesser extent 11KA, increased pituitary LH content in castrated fish, The 11KA increased plasma and pituitary FSH levels, whereas T suppressed FSH in July and stimulated it in November, Plasma FSH levels peak earlier than LH, and it is suggested that if one or more feedback effects are involved in controlling the "all-or-nothing response," i.e., whether a fish will mature or not, a feedback effect on FSH is the most likely candidate. C1 Univ Stockholm, Dept Zool, S-10691 Stockholm, Sweden. Univ Lund, Dept Zool, S-22362 Lund, Sweden. Swedish Univ Agr Sci, Dept Aquaculture, S-90183 Umea, Sweden. NOAA, Natl Marine Fisheries Serv, NW Fisheries Ctr, Seattle, WA 98112 USA. RP Borg, B (reprint author), Univ Stockholm, Dept Zool, S-10691 Stockholm, Sweden. EM borg@zoologi.su.se RI Antonopoulou, Efthimia/N-4233-2015; Andersson, Eva/C-1824-2012; OI Andersson, Eva/0000-0002-7864-1014; Antonopoulou, Efthimia/0000-0003-4565-6962 NR 33 TC 61 Z9 62 U1 1 U2 6 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 USA SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD MAR PY 1998 VL 58 IS 3 BP 814 EP 820 DI 10.1095/biolreprod58.3.814 PG 7 WC Reproductive Biology SC Reproductive Biology GA YY851 UT WOS:000072193100026 PM 9510971 ER PT J AU Meuse, CW Krueger, S Majkrzak, CF Dura, JA Fu, J Connor, JT Plant, AL AF Meuse, CW Krueger, S Majkrzak, CF Dura, JA Fu, J Connor, JT Plant, AL TI Hybrid bilayer membranes in air and water: Infrared spectroscopy and neutron reflectivity studies SO BIOPHYSICAL JOURNAL LA English DT Article ID LIPID BILAYERS; GEL PHASE; GOLD SURFACES; MONOLAYERS; DIPALMITOYLPHOSPHATIDYLCHOLINE; TEMPERATURE; SCATTERING; BIOSENSORS; LAYERS; IR AB In this report we describe the fabrication and characterization of a phospholipid/alkanethiol hybrid bilayer membrane in air. The bilayer is formed by the interaction of phospholipid with the hydrophobic surface of a self-assembled alkanethiol monolayer on gold. We have characterized the resulting hybrid bilayer membrane in air using atomic force microscopy, spectroscopic ellipsometry, and reflection-absorption infrared spectroscopy. These analyses indicate that the phospholipid added is one monolayer thick, is continuous, and exhibits molecular order which is similar to that observed for phospholipid/phospholipid model membranes. The hybrid bilayer prepared in air has also been re-introduced to water and characterized using neutron reflectivity and impedance spectroscopy. Impedance data indicate that when moved from air to water, hybrid bilayers exhibit a dielectric constant and thickness that is essentially equivalent to hybrid bilayers prepared in situ by adding phospholipid vesicles to alkanethiol monolayers in water. Neutron scattering from these samples was collected out to a wave vector transfer of 0.25 Angstrom(-1), and provided a sensitivity to changes in total layer thickness on the order of 1-2 Angstrom. The data confirm that the acyl chain region of the phospholipid layer is consistent with that observed for phospholipid-phospholipid bilayers, but suggest greater hydration of the phospholipid headgroups of HBMs than has been reported in studies of lipid multilayers. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Plant, AL (reprint author), Case Western Reserve Univ, Dept Biomed Engn, Cleveland, OH 44106 USA. RI Dura, Joseph/B-8452-2008 OI Dura, Joseph/0000-0001-6877-959X NR 44 TC 91 Z9 93 U1 2 U2 11 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD MAR PY 1998 VL 74 IS 3 BP 1388 EP 1398 PG 11 WC Biophysics SC Biophysics GA ZL097 UT WOS:000073398500025 PM 9512035 ER PT J AU Cronin, G AF Cronin, G TI Between-species and temporal variation in Acacia-ant-herbivore interactions SO BIOTROPICA LA English DT Article DE Acacia; Acacia-ants; induction; mutualism; plant-ant-herbivore interactions; Pseudomyrmex ID PLANT; DEFENSES; MUTUALISM; BALANCE; ECOLOGY; GROWTH; LEAVES; BIRDS C1 Univ N Carolina, Inst Marine Sci, Morehead City, NC 28557 USA. RP Cronin, G (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, NOAA, Boulder, CO 80309 USA. NR 38 TC 16 Z9 18 U1 3 U2 16 PU ASSOC TROPICAL BIOLOGY INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0006-3606 J9 BIOTROPICA JI Biotropica PD MAR PY 1998 VL 30 IS 1 BP 135 EP 139 DI 10.1111/j.1744-7429.1998.tb00377.x PG 5 WC Ecology SC Environmental Sciences & Ecology GA ZG159 UT WOS:000072972300014 ER PT J AU Andreas, EL Hill, RJ Gosz, JR Moore, DI Otto, WD Sarma, AD AF Andreas, EL Hill, RJ Gosz, JR Moore, DI Otto, WD Sarma, AD TI Statistics of surface-layer turbulence over terrain with metre-scale heterogeneity SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE Bowen ratio; heterogeneous terrain; Monin-Obukhov similarity; skewness of temperature; sonic anemometer/thermometer; statistics of turbulence ID SONIC ANEMOMETER; BOUNDARY-LAYER; SENSIBLE HEAT; URBAN SURFACE; WATER-VAPOR; TEMPERATURE; SIMILARITY; FLUX; MOMENTUM; FLUCTUATIONS AB The Sevilleta National Wildlife Refuge has patchy vegetation in sandy soil. During midday and at night, the surface sources and sinks for heat and moisture may thus be different. Although the Sevilleta is broad and level, its metre-scale heterogeneity could therefore violate an assumption on which Monin-Obukhov similarity theory (MOST) relies. To test the applicability of MOST in such a setting, we measured the standard deviations of vertical (sigma(w)) and longitudinal velocity (sigma(u)), temperature (sigma(t)), and humidity (sigma(q)), the temperature-humidity covariance (<(tq)over bar>), and the temperature skewness (St). Dividing the former five quantities by the appropriate flux scales (u*, t*, and q*) yielded the nondimensional statistics sigma(w)/u*, sigma(u)/u*, sigma(t)//t*/, sigma(q)//q*/, and <(tq)over bar>/t*q*, sigma(w)/u*, sigma(t)//t*/, and St have magnitudes and variations with stability similar to those reported in the literature and, thus, seem to obey MOST. Though sigma(u)/u* is often presumed not to obey MOST, our sigma u/u*, data also agree with MOST scaling arguments. While sigma(q)//q*/ has the same dependence on stability as sigma(t)//t*/, its magnitude is 28% larger When we ignore <(tq)over bar>/t*q* values measured during sunrise and sunset transitions - when MOST is not expected to apply - this statistic has essentially the same magnitude and stability dependence as (sigma(t)/t*)(2). In a flow that truly obeys MOST, (sigma(t)/t*)(2), (sigma(q)/q*)(2), and <(tq)over bar>/t*q* should all have the same functional form. That (sigma(q)/q*)(2) differs from the other two suggests that the Sevilleta has an interesting surface not compatible with MOST. The sources of humidity reflect the patchiness while, despite the patchiness, the sources of heat seem uniformly distributed. C1 USA, Cold Reg Res & Engn Lab, Hanover, NH 03755 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. Osmania Univ, R&T Unit Navigat Elect, Hyderabad 500007, Andhra Pradesh, India. RP Andreas, EL (reprint author), USA, Cold Reg Res & Engn Lab, 72 Lyme Rd, Hanover, NH 03755 USA. NR 49 TC 77 Z9 88 U1 1 U2 6 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 1998 VL 86 IS 3 BP 379 EP 408 DI 10.1023/A:1000609131683 PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZR367 UT WOS:000073967500002 ER PT J AU Andreas, EL Hill, RJ Gosz, JR Moore, DI Otto, WD Sarma, AD AF Andreas, EL Hill, RJ Gosz, JR Moore, DI Otto, WD Sarma, AD TI Stability dependence of the eddy-accumulation coefficients for momentum and scalars SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE eddy-accumulation coefficients; eddy-accumulation method; flux-measurement techniques; momentum flux; scalar flux; sonic anemometer/thermometer ID FLUX MEASUREMENT; PROBABILITY DENSITY; SURFACE-LAYER; TEMPERATURE; SYSTEM AB From a set of turbulence data collected with a three-axis sonic anemometer/thermometer and described in a companion paper, we simulate the eddy-accumulation process for sensible heat and momentum fluxes. The resulting eddy-accumulation coefficient for momentum clearly depends on surface-layer stability; at neutral stability, its value is 0.63. On supplementing the scalar eddy-accumulation coefficients that we derive from our sensible heat flux data with values of sensible and latent heat flux coefficients reported by Businger and Oncley, we also find that scalar eddy-accumulation coefficients depend on stability though more weakly than does the momentum coefficient. The coefficients for sensible and latent heat show no significant difference; we, thus, fit them with one function of stability whose value is 0.52 for neutral stratification. C1 USA, Cold Reg Res & Engn Lab, Hanover, NH 03755 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. Osmania Univ, R&T Unit Navigat Elect, Hyderabad 500007, Andhra Pradesh, India. RP Andreas, EL (reprint author), USA, Cold Reg Res & Engn Lab, 72 Lyme Rd, Hanover, NH 03755 USA. NR 29 TC 26 Z9 26 U1 0 U2 5 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD MAR PY 1998 VL 86 IS 3 BP 409 EP 420 DI 10.1023/A:1000625502550 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZR367 UT WOS:000073967500003 ER PT J AU Mahrt, L Vickers, D Edson, J Sun, JL Hojstrup, J Hare, J Wilczak, JM AF Mahrt, L Vickers, D Edson, J Sun, JL Hojstrup, J Hare, J Wilczak, JM TI Heat flux in the coastal zone SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE surface heat flux; sea surface fluxes; marine boundary layer; Monin-Obukhov similarity ID ATMOSPHERIC BOUNDARY-LAYER; AIR-SEA EXCHANGE; SURFACE FLUXES; TURBULENT FLUXES; SENSIBLE HEAT; WATER-VAPOR; WIND; VELOCITY; INTERFACE; STABILITY AB Various difficulties with application of Monin-Obukhov similarity theory are surveyed including the influence of growing waves, advection and internal boundary-layer development. These complications are normally important with offshore flow. The transfer coefficient for heat is computed from eddy correlation data taken at a mast two kilometres off the Danish coast in RASEX. For these coastal zone data, the thermal roughness length shows no well-defined relation to the momentum roughness length or roughness Reynolds number, in contrast to previous theories. The variation of the momentum roughness length is dominated by wave state. In contrast, the thermal roughness length shows significant dependence on wave state only for small values of wave age where the mixing is apparently enhanced by wave breaking. The development of thin internal boundary layers with offshore flow substantially reduces the heat transfer and thermal roughness length but has no obvious influence on momentum roughness length. A new formulation of the thermal roughness length based on the internal boundary-layer depth is calibrated to the RASEX data. For the very stable case, the turbulence is mainly detached from the surface and existing formulations do not apply. As an alternative to adjusting the thermal roughness length, the transfer coefficient is related directly to the stability and the internal boundary-layer depth. This avoids specification of roughness lengths resulting from the usual integration of the non-dimensional temperature function. The resulting stability function is simpler than previous ones and satisfies free convection similarity theory without introduction of the gustiness factor. The internal boundary layer also influences the moisture transfer coefficient. C1 Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. Riso Natl Lab, Dept Meteorol & Wind Energy, DK-4000 Roskilde, Denmark. Univ Colorado, NOAA, CIRES, Boulder, CO 80303 USA. NOAA, ERL, Environm Technol Lab, Boulder, CO 80303 USA. RP Mahrt, L (reprint author), Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. RI Sun, Jielun/H-6576-2015 OI Sun, Jielun/0000-0003-3271-7914 NR 56 TC 30 Z9 31 U1 2 U2 8 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 1998 VL 86 IS 3 BP 421 EP 446 DI 10.1023/A:1000784219817 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZR367 UT WOS:000073967500004 ER PT J AU Travis, J Coleman, FC Grimes, CB Conover, D Bert, TM Tringali, M AF Travis, J Coleman, FC Grimes, CB Conover, D Bert, TM Tringali, M TI Critically assessing stock enhancement: An introduction to the Mote Symposium SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium in Fisheries Ecology CY NOV 20-23, 1996 CL MOTE MARINE LAB, SARASOTA, FLORIDA SP Florida State Univ HO MOTE MARINE LAB AB Stock enhancement represents a potential component of an economically viable and ecologically sound management strategy for many marine fisheries in danger of collapse. Stock enhancement is appealing because of its straightforward logic: by raising large numbers of larvae or juveniles and then releasing them into the marine environment, we can compensate for the enormous natural mortality in these stages and thereby increase the stock size in the late juvenile and early adult stages of the life cycle, which in turn will compensate for the fishing mortality that depleted the stock. Many questions remain, however, about the economic and ecological soundness of this strategy. These questions reach into virtually every area of environmental biology from population dynamics and genetics to ecosystem processes and resource economics. This first William R. and Lenore Mote Symposium is designed to focus attention on these questions, suggest profitable avenues of research toward the answers, and lead to an increasingly discerning view of when and where in the marine environment stock enhancement is likely to succeed. C1 Florida State Univ, Dept Biol Sci, Inst Fishery Resource Ecol, Tallahassee, FL 32306 USA. Natl Marine Fisheries Serv, SEFSC Panama City Lab, Panama City, FL 32408 USA. SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. Florida Dept Environm Protect, Florida Marine Res Inst, St Petersburg, FL 33701 USA. RP Travis, J (reprint author), Florida State Univ, Dept Biol Sci, Inst Fishery Resource Ecol, B-157, Tallahassee, FL 32306 USA. NR 11 TC 50 Z9 51 U1 1 U2 2 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD MAR PY 1998 VL 62 IS 2 BP 305 EP 311 PG 7 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 132DL UT WOS:000076615000002 ER PT J AU Stoner, AW Glazer, RA AF Stoner, AW Glazer, RA TI Variation in natural mortality: Implications for queen conch stock enhancement SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium in Fisheries Ecology CY NOV 20-23, 1996 CL MOTE MARINE LAB, SARASOTA, FLORIDA SP Florida State Univ HO MOTE MARINE LAB ID STROMBUS-GIGAS; JUVENILE; GROWTH; AGGREGATION; PREDATION; GASTROPOD; SIZE; SURVIVORSHIP; POPULATIONS; RECRUITMENT AB Our long-term investigations of mortality and predation in the large, economically significant gastropod Strombus gigas (queen conch) indicate that instantaneous rates of natural mortality (M) in nursery grounds in the Bahamas and the Florida Keys are often higher and more variable than recognized earlier. Wide divergence from a simple size-specific curve of natural mortality was caused by seasonal, interannual, and site-specific sources of variation. In the Florida Keys, mortality rates for 200-mm conch were highest in summer and most stable in the fall, but summer values of M varied interannually from <2.0 to 12.0. Mortality rates for 100-mm conch, often considered ideal in size for field releases, varied from 0.5 to 12.0, depending on site, season, conch density, and deficits in behavior and shell form associated with hatchery rearing. Unlike many marine invertebrates, juvenile queen conch have an inverse density dependence in mortality. Because of the logarithmic relationship between mortality rate and the cost to enhance a stock, it is critical for those involved in stock enhancement to have a realistic understanding of mortality processes and effects and to optimize culture and release strategies for highest possible survival. Specific recommendations are made for queen conch releases. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Highlands, NJ 07723 USA. Florida Marine Res Inst, Dept Environm Protect, Marathon, FL 33050 USA. RP Stoner, AW (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 74 Magruder Rd, Highlands, NJ 07723 USA. NR 51 TC 22 Z9 24 U1 0 U2 6 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD MAR PY 1998 VL 62 IS 2 BP 427 EP 442 PG 16 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 132DL UT WOS:000076615000010 ER PT J AU Cooney, RT Brodeur, RD AF Cooney, RT Brodeur, RD TI Carrying capacity and North Pacific salmon production: Stock-enhancement implications SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium in Fisheries Ecology CY NOV 20-23, 1996 CL MOTE MARINE LAB, SARASOTA, FLORIDA SP Florida State Univ HO MOTE MARINE LAB ID SUB-ARCTIC PACIFIC; PRINCE-WILLIAM-SOUND; CHUM SALMON; ONCORHYNCHUS-KETA; BRITISH-COLUMBIA; JUVENILE PINK; ZOOPLANKTON BIOMASS; CALIFORNIA CURRENT; SOCKEYE-SALMON; BERING SEA AB Ocean-ranching programs in Asia and North America are supplementing, or have replaced, the natural production of some salmonid populations feeding and maturing in the North Pacific Ocean. These activities, coupled with favorable survival conditions, have raised many stocks to historical or near historical highs during the last decade and a half. Studies of ocean forage production and the response of nekton populations to changes in levels of forage demonstrate multi-year and interdecadal variability attributed to large-scale atmospheric cycles. The period since the most recent regime shift favored salmon production in Alaska waters, but not off Washington and Oregon. We present modeled estimates of the forage demand placed on coastal and oceanic feeding areas by wild and ocean-ranched pink salmon originating from Prince William Sound, Alaska, as a case history. Annual food consumption for these stocks rose from less than 100,000 mt prior to 1976 to more than 300,000 mt after 1988, when hatchery production began dominating adult returns. Food demand was distributed nearly equally between survivors and nonsurvivors, and most of the food consumption occurred in the oceanic rather than coastal environments. Because, for all species, adults that return at smaller than average size are less fecund and produce smaller eggs and fry, increased competition for food resulting in smaller body size could influence the survival of progeny, with serious consequences for both wild and hatchery populations. Studies suggest that competition can result from increased salmon production, diminished forage production, and decreases in the size of ocean feeding domains. C1 Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Cooney, RT (reprint author), Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. NR 74 TC 35 Z9 37 U1 1 U2 9 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD MAR PY 1998 VL 62 IS 2 BP 443 EP 464 PG 22 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 132DL UT WOS:000076615000011 ER PT J AU Olla, BL Davis, MW Ryer, CH AF Olla, BL Davis, MW Ryer, CH TI Understanding how the hatchery environment represses or promotes the development of behavioral survival skills SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium in Fisheries Ecology CY NOV 20-23, 1996 CL MOTE MARINE LAB, SARASOTA, FLORIDA SP Florida State Univ HO MOTE MARINE LAB ID SALMON ONCORHYNCHUS-KISUTCH; JUVENILE COHO SALMON; COD GADUS-MORHUA; ATLANTIC SALMON; PREDATOR-AVOIDANCE; FORAGING BEHAVIOR; FOOD DISTRIBUTION; AGONISTIC BEHAVIOR; RAINBOW-TROUT; BROWN TROUT AB Although great strides have been made in the development of techniques for rearing marine fish, methods for improving survival capabilities following release of these fish into the natural environment have not kept pace. Most responsible for impeding progress has been the lack of adequate knowledge of the complex interactions between a species and the myriad physical and biological factors a hatchery fish faces upon release. Being reared in the psychosensorily deprived environment of a hatchery may lessen the innate capability of fish to carry out the basic survival strategy of all fish: to eat and not be eaten. In this synthesis we focus on some of the key behaviors that play a role in predator avoidance and food acquisition and on how the rearing environment may affect the expression of these behaviors. One of the major causes of mortality in hatchery-reared fish is predation, much of which occurs shortly after release. Available evidence seems to indicate that antipredator behavior in hatchery-reared fish is not fully developed. Possible deficits may also occur in feeding after release, when fish are faced with the shift from hatchery-supplied foods to the capture of live prey. Added to possible hatchery-induced deficits in behavior are the alterations in behavior that may result from the stress of handling and transportation. Behavioral capabilities in hatchery-reared fish can be improved in a number of ways, including exposure to predators err predatory stimuli, alteration of spatial and temporal distribution of food mitigation of rearing and transport stress, and control of the social environment. C1 Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv,Alaska Fisheries Sci C, Fisheries Behav Ecol Program, Newport, OR 97365 USA. RP Olla, BL (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv,Alaska Fisheries Sci C, Fisheries Behav Ecol Program, Newport, OR 97365 USA. RI 平山, 幸恵/G-9307-2012 NR 94 TC 177 Z9 180 U1 5 U2 36 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD MAR PY 1998 VL 62 IS 2 BP 531 EP 550 PG 20 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 132DL UT WOS:000076615000016 ER PT J AU Epstein, PR Diaz, HF Elias, S Grabherr, G Graham, NE Martens, WJM Mosley-Thompson, E Susskind, J AF Epstein, PR Diaz, HF Elias, S Grabherr, G Graham, NE Martens, WJM Mosley-Thompson, E Susskind, J TI Biological and physical signs of climate change: Focus on mosquito-borne diseases SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID INFECTIOUS-DISEASES; DENGUE FEVER; MALARIA; TRANSMISSION; TEMPERATURE; CALIFORNIA; TRENDS; OCEAN; BIODIVERSITY; SIMULATION AB The Intergovernmental Panel on Climate Change concluded that there is "discernible evidence" that humans-through accelerating changes in multiple forcing factors-have begun to alter the earth's climate regime. Such conclusions are based primarily upon so-called "fingerprint" studies, namely the warming pattern in the midtroposphere in the Southern Hemisphere, the disproportionate rise in nighttime and winter temperatures, and the statistical increase in extreme weather events in many nations. All three aspects of climate change and climate variability have biological implications. Detection of climate change has also drawn upon data from glacial records that indicate a general retreat of tropical summit glaciers. Here the authors examine biological (plant and insect) data, glacial findings, and temperature records taken at high-elevation, mountainous regions. It is concluded that, at high elevations, the overall trends regarding glaciers, plants, insect range, and shifting isotherms show remarkable internal consistency, and that there is consistency between model projections and the ongoing changes. There are implications for public health as well as for developing an interdisciplinary approach to the detection of climate change. C1 Harvard Univ, Sch Med, Oliver Wendell Holmes Soc, Ctr Hlth & Global Environm, Boston, MA 02115 USA. NOAA, Environm Res Lab, Climat Diag Ctr, Boulder, CO 80303 USA. Univ Colorado, Boulder, CO 80309 USA. Univ Vienna, Dept Vegetat Ecol & Conservat Biol, A-1010 Vienna, Austria. Scripps Inst Oceanog, Int Res Inst Climat Predict, La Jolla, CA USA. Maastricht Univ, Dept Math, Maastricht, Netherlands. Ohio State Univ, Byrd Polar Res Ctr, Dept Geog, Columbus, OH 43210 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Epstein, PR (reprint author), Harvard Univ, Sch Med, Oliver Wendell Holmes Soc, Ctr Hlth & Global Environm, Room 263,260 Londwood Ave, Boston, MA 02115 USA. EM PEPSTEIN@warren.med.harvard.edu RI Martens, Pim/A-9297-2011 NR 85 TC 99 Z9 107 U1 11 U2 37 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 MAR PY 1998 VL 79 IS 3 BP 409 EP 417 DI 10.1175/1520-0477(1998)079<0409:BAPSOC>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZE363 UT WOS:000072785100002 ER PT J AU Angevine, WM Grimsdell, AW Hartten, LM Delany, AC AF Angevine, WM Grimsdell, AW Hartten, LM Delany, AC TI The Flatland boundary layer experiments SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID WIND PROFILER; JULY 1995; HEAT-WAVE AB This article describes the 1995 and 1996 Flatland boundary layer experiments, known as Flatland95 and Flatland96.: A number of scientific and instrumental objectives were organized around the central theme of characterization of the convective boundary layer, especially the boundary layer top and entrainment zone. In this article the authors describe the objectives and physical setting of the experiments, which took place in the area near the Flatland Atmospheric Observatory, near Champaign-Urbana, Illinois, in August-September 1995 and June-August 1996. The site is interesting because it is extremely flat, has uniform land use, and is in a prime agricultural area. The instruments used and their performance are also discussed. The primary instruments were a triangle of UHF wind-profiling radars. Rawinsondes and surface meteorological and flux instruments were also included. Finally, some early results in terms of statistics and several case studies are presented. C1 Univ Colorado, CIRES, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Angevine, WM (reprint author), NOAA, Aeron Lab REAL3, CIRES, Boulder, CO 80303 USA. RI Hartten, Leslie/F-1970-2010; Angevine, Wayne/H-9849-2013 OI Hartten, Leslie/0000-0002-5620-6302; Angevine, Wayne/0000-0002-8021-7116 NR 25 TC 39 Z9 42 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1998 VL 79 IS 3 BP 419 EP 431 DI 10.1175/1520-0477(1998)079<0419:TFBLE>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZE363 UT WOS:000072785100003 ER PT J AU Moran, KP Martner, BE Post, MJ Kropfli, RA Welsh, DC Widener, KB AF Moran, KP Martner, BE Post, MJ Kropfli, RA Welsh, DC Widener, KB TI An unattended cloud-profiling radar for use in climate research SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID DOPPLER RADAR; PARTICLE SIZES; FIRE-II; PRECIPITATION; PARAMETERS; TURBULENCE; ASTEX AB A new millimeter-wave cloud radar (MMCR) has been designed to provide detailed, long-term observations of nonprecipitating and weakly precipitating clouds at Cloud and Radiation Testbed (CART) sites of the Department of Energy's Atmospheric Radiation Measurement (ARM) program. Scientific requirements included excellent sensitivity and vertical resolution to detect weak and thin multiple layers of ice and liquid water clouds over the sites and longterm, unattended operations in remote locales. ln response to these requirements, the innovative radar design features a vertically pointing, single-polarization, Doppler system operating at 35 GHz (K-a band). It uses a low-peak-power transmitter for long-term reliability and high-gain antenna and pulse-compressed waveforms to maximize sensitivity and resolution. The radar uses the same kind of signal processor as that used in commercial wind profilers. The first MMCR began operations at the CART in northern Oklahoma in late 1996 and has operated continuously there for thousands of hours. It routinely provides remarkably detailed images pf the ever-changing cloud structure and kinematics over this densely instrumented site. Examples of the data are presented. The radar measurements will greatly improve quantitative documentation of cloud conditions over the CART sites and will bolster ARM research to understand how clouds impact climate through their effects on radiative transfer. Millimeter-wave radars such as the MMCR also have potential applications in the fields of aviation weather, weather modification, and basic cloud physics research. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Pacific NW Natl Lab, Richland, WA USA. RP Moran, KP (reprint author), NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. NR 36 TC 219 Z9 224 U1 3 U2 12 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 MAR PY 1998 VL 79 IS 3 BP 443 EP 455 DI 10.1175/1520-0477(1998)079<0443:AUCPRF>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZE363 UT WOS:000072785100005 ER PT J AU Bastiaans, LM Smith, DR McPherson, RA Phoebus, PA Moran, JM Croft, PJ Ceritelli, MJ Rao, GV Schaefer, JT Gadomski, FJ Kloesel, KA Quayle, RG Zeitler, JW AF Bastiaans, LM Smith, DR McPherson, RA Phoebus, PA Moran, JM Croft, PJ Ceritelli, MJ Rao, GV Schaefer, JT Gadomski, FJ Kloesel, KA Quayle, RG Zeitler, JW TI The Sixth AMS Symposium on Education SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material AB The American Meteorological Society held its Sixth Symposium on Education in conjunction with the 77th Annual Meeting in Long Beach, California. The theme of the symposium was "Atmospheric and Oceanographic Education:Teaching about the Global Environment." Thirty-eight oral presentations and 37 poster presentations summarized a variety of educational programs or examined educational issues for both the precollege and university levels. There was also a joint session with the Eighth Symposium on Global Change Studies and a special session on "home pages" to promote popular meteorological education. Over 200 people representing a wide spectrum of the Society attended one or more of the sessions in this two-day conference where they increased their awareness of teaching about the global environment. C1 USN Acad, Dept Oceanog, Annapolis, MD 21402 USA. Nassau Cty Community Coll, Dept Phys Sci, Garden City, NY USA. Oklahoma Climate Survey, Norman, OK USA. USN, Res Lab, Monterey, CA USA. Univ Wisconsin, Coll Environm Sci, Green Bay, WI 54302 USA. Jackson State Univ, Dept Phys & Atmospher Sci, Jackson, MS USA. Immaculate Concept Sch, Columbus, OH USA. St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63103 USA. Natl Storms Predict Ctr, Norman, OK USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Natl Climat Data Ctr, Asheville, NC USA. Natl Weather Serv, Rapid City, SD USA. RP Smith, DR (reprint author), USN Acad, Dept Oceanog, 572 Holloway Rd, Annapolis, MD 21402 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1998 VL 79 IS 3 BP 457 EP 466 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZE363 UT WOS:000072785100006 ER PT J AU Moles, A Norcross, BL AF Moles, A Norcross, BL TI Effects of oil-laden sediments on growth and health of juvenile flatfishes SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID CRUDE-OIL; PLEURONECTES-AMERICANUS; WINTER FLOUNDER; EXXON-VALDEZ; FISH; EXPOSURE; PLATESSA; SPILL AB Juvenile yellowfin sole (Pleuronectes asper), rock sole (Pleuronectes bilineatus), and Pacific halibut (Hippoglossus stenolepis) had reduced growth following 30-90 days of exposure to sediments laden with Alaska North Slope crude oil. Changes in fish health bioindicators after 90 days, i.e., increases in fin erosion, liver lipidosis, gill hyperplasia, and gill parasites, coupled with decreases in macrophage aggregates, occurred at hydrocarbon concentrations (1600 mu g/g) that reduced growth 34-56% among the flatfishes. Chronic hydrocarbon pollution of nearshore nursery sediments could alter growth and health of juvenile flatfishes. Recruitment of juveniles to the fishery may decline because of increased susceptibility to predation and slower growth. C1 NOAA, Auke Bay Lab, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Juneau, AK 99801 USA. Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. RP Moles, A (reprint author), NOAA, Auke Bay Lab, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 20 TC 32 Z9 33 U1 2 U2 14 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 1998 VL 55 IS 3 BP 605 EP 610 DI 10.1139/cjfas-55-3-605 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA ZR921 UT WOS:000074029600008 ER PT J AU Watters, G Hobday, AJ AF Watters, G Hobday, AJ TI A new method for estimating the morphometric size at maturity of crabs SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID MALE SNOW CRAB; EASTERN BERING-SEA; REPRODUCTIVE-BIOLOGY; FUNCTIONAL MATURITY; CHIONOECETES-BAIRDI; SEXUAL MATURITY; KING CRAB; CHINONOECETES-OPILIO; RETHINKING ALLOMETRY; PARALOMIS-GRANULOSA AB Existing techniques for estimating the morphometric size at maturity of crabs are based on assumptions that may be unnecessary. Here we demonstrate a new method of detecting changes in relative growth (or allometric) relationships and estimating morphometric size at maturity. This method involves fitting several smoothing splines to relationships between body size and claw size, selecting the "best" spline, and finding this spline's maximum second derivative. The body size where the second derivative of the best spline is maximized estimates the morphometric size at maturity. Monte Carlo simulations suggest that uncertainty and bias in the estimate of morphometric size at maturity can be decreased by measuring a large number of crabs from a wide range of body sizes. Our spline method does not require a priori assumptions about the shape of the relative growth relationship; it can detect multiple changes in the relative growth rate; and it is robust to outliers. The modeling technique may also be used to identify regions of allometric change in other types of relationships. We demonstrate the new technique by estimating the morphometric size at sexual maturity for males of both brachyuran (Chibnoecetes tanneri) and anomuran (Paralomis spinosissima and P. formosa) crabs. C1 NOAA, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. RP InterAmer Trop Tuna Commiss, 8604 La Jolla Shores Dr, La Jolla, CA 92037 USA. EM gwatters@iattc.ucsd.edu RI Hobday, Alistair/A-1460-2012 OI Hobday, Alistair/0000-0002-3194-8326 NR 52 TC 17 Z9 17 U1 0 U2 3 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0706-652X EI 1205-7533 J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD MAR PY 1998 VL 55 IS 3 BP 704 EP 714 DI 10.1139/cjfas-55-3-704 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA ZR921 UT WOS:000074029600019 ER PT J AU Dittman, AH Brown, GS Foote, CJ AF Dittman, AH Brown, GS Foote, CJ TI The role of chemoreception in salmon-egg predation by coastrange (Cottus aleuticus) and slimy (C-cognatus) sculpins in Iliamna Lake, Alaska SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID ONCORHYNCHUS-NERKA; MOTTLED SCULPIN; SOCKEYE-SALMON; REPRODUCTIVE-BEHAVIOR; ARCTIC LAKE; BAIRDI; CUES; SUBSTRATE; COTTIDAE; SIZE AB Egg predation by coastrange sculpins (Cottus aleuticus) and slimy sculpins (C. cognatus) may be a major factor affecting sockeye salmon (Oncorhynchus nerka) production in Iliamna Lake, Alaska. In this study, we examined the potential roles of visual and chemosensory cues in egg predation by sculpins. A field study tested whether sculpins were differentially attracted to minnow traps baited with eggs that were (i) visible with no odours present, (ii) visible with odours present, or (iii) not visible with odours present. Our results indicated that sculpins do not require visual cues for detecting salmon eg: However, attraction to sockeye eggs did require chemical cues emanating from the eggs. To characterize the chemical attractants that emanate from salmon eggs, we tested whether sculpins were attracted to test odours in a two-choice maze. Test odours were prepared by soaking eggs in lake water. Sculpins preferred egg wash to lake water but demonstrated no attraction to ovarian fluid versus lake water, suggesting that the attractive substances are derived directly from egg material. These results are discussed in relation to the known sensory mechanisms involved in feeding by sculpins as well as to the ecological relationship between spawning sockeye salmon and sculpins. C1 Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. US Geol Survey, NW Biol Sci Ctr, Seattle, WA 98115 USA. RP Dittman, AH (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, 269 Life Sci Addit, Berkeley, CA 94720 USA. NR 49 TC 12 Z9 13 U1 3 U2 6 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 MAR PY 1998 VL 76 IS 3 BP 406 EP 413 PG 8 WC Zoology SC Zoology GA ZZ342 UT WOS:000074719800003 ER PT J AU Pozsgay, V Sari, N Coxon, B AF Pozsgay, V Sari, N Coxon, B TI Measurement of interglycosidic (3)J(CH) coupling constants of selectively C-13 labeled oligosaccharides by 2D J-resolved H-1 NMR spectroscopy SO CARBOHYDRATE RESEARCH LA English DT Article DE trisaccharide; tetrasaccharide; pentasaccharide; oligosaccharides; carbon-13 labeling; carbon-13-proton coupling constants; Shigella dysenteriae type 1; 2D J-resolved NMR spectroscopy ID SHIGELLA-DYSENTERIAE TYPE-1; NUCLEAR-MAGNETIC-RESONANCE; O-SPECIFIC POLYSACCHARIDE; STEREOSELECTIVE SYNTHESIS; DETECTED MEASUREMENTS; CHEMICAL-SHIFTS; FRAGMENT; CONFORMATION; SACCHARIDES; MOLECULES AB Tri-, tetra-, and penta-saccharide fragments of the O-specific polysaccharide of Shigella dysenteriae type 1 have been prepared in which a D-galactose residue of each oligosaccharide methyl glycoside derivative contains a C-13 label at C-1. The interglycosidic coupling constants ((3)J(CH)) of these C-13 nuclei with the H-3 nuclei of the adjacent 2-acetamido-2-deoxy-D-glucose residues have been measured by two-dimensional, J-resolved H-1 NMR spectroscopy. The magnitudes of these coupling constants indicate that the trisaccharide is conformationally different to the higher oligosaccharide homologs, in agreement with previous studies of C-13 chemical shifts and (1)J(CH) values. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NICHHD, Dev & Mol Immun Lab, NIH, Bethesda, MD 20892 USA. RP Coxon, B (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 36 TC 7 Z9 7 U1 2 U2 4 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 PY 1998 VL 308 IS 1-2 BP 229 EP 238 DI 10.1016/S0008-6215(98)00047-0 PG 10 WC Biochemistry & Molecular Biology; Chemistry, Applied; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA ZW994 UT WOS:000074469700031 PM 9675362 ER PT J AU Roosen, AR McCormack, RP Carter, WC AF Roosen, AR McCormack, RP Carter, WC TI Wulffman: A tool for the calculation and display of crystal shapes SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article AB A computational tool called Wulffman has been developed to determine, quickly and easily, the shape with minimal surface energy (Wulff shape) for solids of arbitrary crystallographic symmetry. The Wulff shape is often the equilibrium or growth shape of the crystal and can be an important contributor in determining the physical properties of a material. Input quantities to the software are the point group symmetry of the shape and several crystal facet directions (along with their energies). Wulffman generates all symmetry-equivalent planes and then computes the Wulff shape. This shape is sent to a public domain 3D visualization environment (Geomview) where it can be viewed and manipulated. The software allows users to interactively see the effects of changes in surface energy. Users may also simulate partially-faceted shapes and 'cleavage' of the Wulff shape. Wulffman is public domain software available via the World-Wide Web. (C) 1998 Elsevier Science B.V. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Ctr Theoret & Computat Mat Sci, Mat Sci Engn Lab, Gaithersburg, MD 20899 USA. RP Roosen, AR (reprint author), Natl Inst Stand & Technol, Div Ceram, 223-A329, Gaithersburg, MD 20899 USA. RI Carter, W/K-2406-2012 NR 10 TC 40 Z9 40 U1 3 U2 20 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 MAR PY 1998 VL 11 IS 1 BP 16 EP 26 DI 10.1016/S0927-0256(97)00167-5 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA ZL196 UT WOS:000073408400002 ER PT J AU Hwang, DM Karimi, HA Byun, DW AF Hwang, DM Karimi, HA Byun, DW TI Uncertainty analysis of environmental models within GIS environments SO COMPUTERS & GEOSCIENCES LA English DT Article DE GIS; sensitivity analysis; automatic differentiation; air quality model ID FUZZY AB Information on the uncertainties in results from Geographic Information Systems (GIS) is needed for effective decision-making. Current GISs, however, do not provide this information. Uncertainties in application models used within GIS environments are a major cause of uncertainties in GIS results. To analyze model uncertainty and its propagation, model sensitivity analysis is first performed. This paper discusses techniques for model sensitivity analysis, model uncertainty analysis, and analysis of the propagation of model uncertainty, within the context of environmental models used within GIS. A two-dimensional air quality model, based on the first-order Taylor method, is used to demonstrate these techniques. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 IBM Corp, Microelect Div, Res Triangle Pk, NC 27709 USA. MCNC, N Carolina Supercomp Ctr, Res Triangle Pk, NC 27709 USA. NOAA, Atmospher Modeling Sci Div, Air Resources Lab, Res Triangle Pk, NC 27711 USA. RP Hwang, DM (reprint author), IBM Corp, Microelect Div, Res Triangle Pk, NC 27709 USA. NR 24 TC 18 Z9 21 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0098-3004 J9 COMPUT GEOSCI-UK JI Comput. Geosci. PD MAR PY 1998 VL 24 IS 2 BP 119 EP 130 DI 10.1016/S0098-3004(97)00133-7 PG 12 WC Computer Science, Interdisciplinary Applications; Geosciences, Multidisciplinary SC Computer Science; Geology GA ZM694 UT WOS:000073566500002 ER PT J AU Park, MS Eanes, ED Antonucci, JM Skrtic, D AF Park, MS Eanes, ED Antonucci, JM Skrtic, D TI Mechanical properties of bioactive amorphous calcium phosphate/methacrylate composites SO DENTAL MATERIALS LA English DT Article ID PHOSPHATE CEMENTS AB Objectives. The aim of this study was to determine whether amorphous calcium phosphate (ACP)-containing composites, which have the ability to release mineralizing levels of Ca and PO4 ions, have appropriate mechanical properties for use as base and lining materials. Methods. Composites of pyrophosphate-stabilized ACP particulates (mass fraction of 40%) and photo-activated methacrylate resins (mass fraction of 60%) were tested for biaxial flexure strength (BFS), diametral tensile strength (DTS), and compressive strength (CS). Hydroxyapatite (HAP; mass fraction of 40%), and micro-sized glass (mass fraction of 50%) composites as well as a commercial visible light curable base/liner were also tested. The significance between mean values was determined by Student-Newman-Keuls multiple comparisons (p < 0.05). Results. BFS of dry and wet (24 h at 37 degrees C in water) ACP composites (60.3 and 62.0 MPa, respectively) were significantly lower than those of the comparison materials (79.2-109.3 MPa). CS values were likewise lower (62.9 MPa dry and 67.6 MPa wet vs 80.6-196.8 MPa) except for the wet base/liner (58.5 MPa). DTS of the dry ACP composite (21.8MPa) was comparable with that of the HAP (22.8 MPa) and glass (25.5 MPa) composites, but tower than that of the base/liner (36.2 MPa). DTS decreased significantly when the ACP composite was wet (17.8 MPa). Significance. These results suggest that the remineralizing ACP polymeric composites, although mechanically weaker in some respects than other polymeric composites, have properties suitable for use as base and lining materials. (C) 1998 Academy of Dental Materials. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, DMMG, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, PRC, ADAHF, Gaithersburg, MD 20899 USA. Phil Dent Clin, Kyung Ki Do, South Korea. NIDR, NIH, Bethesda, MD 20892 USA. RP Antonucci, JM (reprint author), Natl Inst Stand & Technol, DMMG, Bldg 224,Room A143, Gaithersburg, MD 20899 USA. NR 19 TC 40 Z9 41 U1 1 U2 10 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0109-5641 J9 DENT MATER JI Dent. Mater. PD MAR PY 1998 VL 14 IS 2 BP 137 EP 141 DI 10.1016/S0109-5641(98)00020-7 PG 5 WC Dentistry, Oral Surgery & Medicine; Materials Science, Biomaterials SC Dentistry, Oral Surgery & Medicine; Materials Science GA 149QX UT WOS:000077617800007 PM 10023203 ER PT J AU Wilbert, MC Pellegrino, J Zydney, A AF Wilbert, MC Pellegrino, J Zydney, A TI Bench-scale testing of surfactant-modified reverse osmosis/nanofiltration membranes SO DESALINATION LA English DT Article DE membrane fouling; surface characterization; zeta potential; atomic force microscopy; surfactants; reverse osmosis; nanofiltration; surface modification ID ULTRAFILTRATION MEMBRANES; POLYETHYLENE OXIDE; PROTEIN; OPTIMIZATION; PRETREATMENT; LAYER AB An homologous series of polyethylene-oxide surfactants, with either octylphenol or polypropylene oxide "head" groups, were applied to commercial cellulose acetate blend (CA) and polyamide (PA) reverse osmosis (RO) and nanofiltration (NF) membranes. The pressure-normalized permeate flow (NPF) and salt rejection were evaluated before and after fouling with a vegetable protein broth. Surface changes were characterized using atomic force microscopy and electro-kinetic analysis. The transport results from both the swatch and element testing were used in a simple economic model to assess operating costs. Results indicate that cost savings are possible based on the changes in NPF and salt rejection. C1 US Bur Reclamat, Water Treatment Engn & Res, Denver, CO 80225 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. Univ Delaware, Dept Chem Engn, Newark, DE 19716 USA. RP Wilbert, MC (reprint author), US Bur Reclamat, Water Treatment Engn & Res, Denver, CO 80225 USA. OI PELLEGRINO, JOHN/0000-0001-7749-5003 NR 19 TC 43 Z9 48 U1 2 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0011-9164 J9 DESALINATION JI Desalination PD MAR PY 1998 VL 115 IS 1 BP 15 EP 32 PG 18 WC Engineering, Chemical; Water Resources SC Engineering; Water Resources GA ZP087 UT WOS:000073715100002 ER PT J AU Zufall, MJ Bergin, MH Davidson, CI AF Zufall, MJ Bergin, MH Davidson, CI TI Effects of non-equilibrium hygroscopic growth of (NH(4))(2)SO(4) on dry deposition to water surfaces SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID AEROSOL; PARTICLES; ELEMENTS; SIZE AB Growth of hygroscopic aerosols near water surfaces is believed to enhance dry deposition rates, which are a strong function of particle size. Previous dry deposition models estimate hygroscopic growth by assuming equilibrium between aerosols and water vapor (Williams, R. M. Atmos. Environ. 1982, 16, 1933-1938). A model is presented here that combines the relative humidity profile above water surfaces with hygroscopic growth rates for (NH(4))(2)SO(4), assuming cases for a deliquescing and metastable aerosol. Model results show that particles greater than 0.1 mu m in diameter do not grow to their equilibrium size before depositing to a hypothetical water surface. As a consequence, equilibrium models overpredict the effects of hygroscopic growth on deposition velocities by as much as a factor of 5. In addition, model results suggest a significant difference in the deposition velocities of metastable and deliquescing aerosols. Based on measured (NH(4))(2)SO(4) size distributions, overall deposition velocities calculated from a thermodynamic equilibrium model, a mass transfer limited non-equilibrium model with a deliquescing aerosol, and a mass transfer limited non-equilibrium model with a metastable aerosol are 0.11, 0.055, and 0.040 cm/s, respectively. C1 Carnegie Mellon Univ, Dept Civil & Environm Engn, Pittsburgh, PA 15213 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Brookhaven Natl Lab, Environm Chem Div, Upton, NY 11973 USA. RP Zufall, MJ (reprint author), Carnegie Mellon Univ, Dept Civil & Environm Engn, Pittsburgh, PA 15213 USA. EM mz25@andrew.cmu.edu NR 33 TC 8 Z9 8 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAR 1 PY 1998 VL 32 IS 5 BP 584 EP 590 DI 10.1021/es970476r PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA YZ913 UT WOS:000072307100030 ER PT J AU O'Connor, TP Daskalakis, KD Hyland, JL Paul, JF Summers, JK AF O'Connor, TP Daskalakis, KD Hyland, JL Paul, JF Summers, JK TI Comparisons of sediment toxicity with predictions based on chemical guidelines SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE sediment; equilibrium partitioning; acid-volatile sulfide; cooccurrence; measured toxicity ID MARINE AB The U.S. Environmental Protection Agency (EPA) Environmental Monitoring and Assessment Program-Estuaries and the National Oceanic and Atmospheric Administration Bioeffects Surveys provide large data sets with which to test proposed relationships between sediment chemistry and toxicity. We conclude that guidelines based on bulk chemistry can provide useful triggers for further analysis but should not be used alone as indicators of toxicity. The sediment quality criteria for nonionic organic compounds proposed by the EPA are exceeded in so few samples that they may be of limited practical value. Toxicity was present in many cases when acid-volatile sulfide (AVS) concentrations exceeded the sum of concentrations of sulfide-insoluble metals. However, there is no way to test whether that toxicity was due to those trace elements. The AVS criterion is much more sensitive to AVS concentration than to trace metal contamination. C1 NOAA, Natl Status & Trends Program, NORCA21, Silver Spring, MD 20910 USA. NOAA, NORCA, Charleston Off, Charleston, SC 29412 USA. US EPA, Atlantic Ecol Div, Narragansett, RI 02882 USA. US EPA, Gulf Ecol Div, Gulf Breeze, FL 32561 USA. RP O'Connor, TP (reprint author), NOAA, Natl Status & Trends Program, NORCA21, 1305 E West Highway, Silver Spring, MD 20910 USA. NR 16 TC 46 Z9 46 U1 0 U2 3 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD MAR PY 1998 VL 17 IS 3 BP 468 EP 471 DI 10.1897/1551-5028(1998)017<0468:COSTWP>2.3.CO;2 PG 4 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA YZ916 UT WOS:000072307500018 ER PT J AU Currin, CA Pearl, HW AF Currin, CA Pearl, HW TI Epiphytic nitrogen fixation associated with standing dead shoots of smooth cordgrass, Spartina alterniflora SO ESTUARIES LA English DT Article ID SALT-MARSH; SEASONALITY; ALGAE; RATES; GRASS; STEMS AB N-2 fixation associated with the epiphytic community on standing dead Spartina alterniflora shoots was examined in both a natural and transplanted salt marsh in North Carolina. Acetylene reduction (AR) assays were con ducted over a 24-mo period to estimate N-2 fixation rates on standing dead stems and leaves. In the natural salt marsh, mean AR rates ranged from 0.5 mmol C2H4 cm(-2) h(-1) to 14 nmol C2H4 cm(-2) h(-1), while in the transplanted marsh mean AR rates ranged from 1 nmol C2H4 cm(-2) h(-1) to 93 nmol C2H4 cm(-2) h(-1). Diel AR activity of epiphytic communities in both marshes varied seasonally. Midday incubations yielded higher AR rates than nighttime incubations in the spring, white midday incubations in late summer and fall generally yielded AR rates equal to or lower than nighttime incubations. Desiccation during low tides occasionally repressed AR activity, although AR rates quickly rebounded with wetting. AR activity was localized in the epiphytic community, rather than in the underlying Spartina stem material. Based on the measured AR rates and the density of standing dead stems, the annual input of new N to the natural salt marsh via epiphytic N-2 fixation is estimated to be 2.6 g N m(-2) yr(-1). The estimate of annual input of new N to the transplanted marsh is 3.8 g N m(-2) yr(-1). These estimates should be added to previous estimates of N-2 fixation in marsh sediments to estimate the total contribution of new nitrogen to salt marsh nitrogen budgets. C1 NOAA, Natl Marine Fisheries Serv, Beaufort Lab, Beaufort, NC 28516 USA. Univ N Carolina, Inst Marine Sci, Morehead City, NC 28516 USA. RP Currin, CA (reprint author), NOAA, Natl Marine Fisheries Serv, Beaufort Lab, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 34 TC 22 Z9 24 U1 1 U2 7 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD MAR PY 1998 VL 21 IS 1 BP 108 EP 117 DI 10.2307/1352550 PG 10 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA ZC528 UT WOS:000072589400008 ER PT J AU McTigue, TA Zimmerman, RJ AF McTigue, TA Zimmerman, RJ TI The use of infauna by juvenile Penaeus aztecus Ives and Penaeus setiferus (Linnaeus) SO ESTUARIES LA English DT Article ID POSTLARVAL BROWN SHRIMP; TEXAS SALT-MARSH; SPECIES DENSITIES; SOUTH-CAROLINA; MACROBENTHOS; SELECTION; PREDATION; SEAGRASS; FOOD; ASSIMILATION AB Penaeus aztecus Ives, the brown shrimp, and Ponaeus setiferus (Linnaeus), the white shrimp, co-occur in Texas salt marshes as juveniles. Although their life cycles are similar, evidence indicates that the species utilize different resources for the primary faunal element of their diets. Prey selection and growth studies have shown that brown shrimp successfully remove infauna from natural sediment Further, a diet of polychaetes, whether alone or in combination with algae, produced growth in the species. Brown shrimp appear to be trophically linked to infaunal populations, thus the structure and dynamics of the benthic community may directly affect local brown shrimp productivity. Areas dominated by surface-dwelling polychaetes as opposed to deep burrowers may provide more accessible foraging opportunities for juvenile brown shrimp. By contrast, white shrimp neither removed infauna nor grew to a significant degree when provided polychaetes or amphipods as food. White shrimp are omnivorous but do not rely on infaunal material to the same extent as brown shrimp. The primary faunal element in the diet of white shrimp has not yet been identified. The dietary differences between the two species may play a role in determining which species dominates in regions with varying marsh accessibility. Although not the only factors influencing penaeid survival and growth, prey choice and availability may greatly affect production and Local success of penaeid populations. C1 Natl Marine Fisheries Serv, Lafayette Off, Lafayette, LA 70504 USA. Natl Marine Fisheries Serv, Galveston Lab, Galveston, TX 77551 USA. RP McTigue, TA (reprint author), Natl Marine Fisheries Serv, Lafayette Off, POB 42451, Lafayette, LA 70504 USA. NR 55 TC 32 Z9 34 U1 0 U2 4 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD MAR PY 1998 VL 21 IS 1 BP 160 EP 175 DI 10.2307/1352554 PG 16 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA ZC528 UT WOS:000072589400012 ER PT J AU Gilman, JW Lomakin, S Kashiwagi, T VanderHart, DL Nagy, V AF Gilman, JW Lomakin, S Kashiwagi, T VanderHart, DL Nagy, V TI Characterization of flame-retarded polymer combustion chars by solid-state C-13 and Si-29 NMR and EPR SO FIRE AND MATERIALS LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; THERMAL-DEGRADATION; CP/MAS NMR; SPECTROSCOPY; CHEMISTRY; COAL AB We report here on the results of our continuing effort to study the flame-retardant mechanism of silica gel and potassium carbonate. These additives reduce the flammability of a wide variety of common polymers such as polypropylene, nylon, polymethylmethacrylate, poly(vinyl alcohol), and cellulase. In an effort to determine how these additives reduce polymer flammability, we have used electron paramagnetic resonance spectroscopy and solid-state C-13 and Si-29 nuclear magnetic resonance spectroscopy to characterize the combustion chars or residues. These data indicate that, in the case of poly(vinyl alcohol), the additives do not change the type of char formed, but they do change the rate of char formation relative to the rate of fuel generation. We also found that, using only CP/MAS C-13 NMR, there can be significant intensity distortions which complicate interpretation, if the char is hydrogen depleted and contains paramagnetic centres. (C) 1998 John Wiley & Sons, Ltd. C1 Natl Inst Stand & Technol, Fire Sci Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. RP Gilman, JW (reprint author), Natl Inst Stand & Technol, Fire Sci Div, Gaithersburg, MD 20899 USA. NR 25 TC 17 Z9 22 U1 0 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0308-0501 J9 FIRE MATER JI Fire Mater. PD MAR-APR PY 1998 VL 22 IS 2 BP 61 EP 67 DI 10.1002/(SICI)1099-1018(199803/04)22:2<61::AID-FAM639>3.0.CO;2-S PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 140FJ UT WOS:000077076500003 ER PT J AU Peacock, RD Reneke, PA Forney, CL Kostreva, MM AF Peacock, RD Reneke, PA Forney, CL Kostreva, MM TI Issues in evaluation of complex fire models SO FIRE SAFETY JOURNAL LA English DT Article ID SENSITIVITY ANALYSIS; SMOKE AB Several methods of evaluation of the predictive capability have been applied to fire models, but with limited utility. These range from explicit evaluation of the equations used in simple models such as ASET to pointwise evaluation of complex models from numerous computer runs of a model. This paper presents a discussion of the issues involved in conducting an analysis of a complex room fire model. Examples using currently available room fire models are presented. For the models and test cases examined, heat release rate and heat transfer effects dominate the behavior of the models. For simple models like the ASET model, analytical techniques can be readily applied. For more complex fire models, obtaining an overall assessment of the model increases in complexity with the complexity of the model, requiring evaluation of numerous model inputs and outputs. Thus, more directed local investigations are currently the only tractable means of evaluation. Areas for additional research are identified. Published by Elsevier Science Ltd. C1 NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Clemson Univ, Dept Math Sci, Clemson, SC 29634 USA. RP Peacock, RD (reprint author), NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 57 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0379-7112 J9 FIRE SAFETY J JI Fire Saf. J. PD MAR PY 1998 VL 30 IS 2 BP 103 EP 136 DI 10.1016/S0379-7112(97)00061-1 PG 34 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA ZK853 UT WOS:000073370400001 ER PT J AU McGrattan, KB Baum, HR Rehm, RG AF McGrattan, KB Baum, HR Rehm, RG TI Large Eddy simulations of smoke movement SO FIRE SAFETY JOURNAL LA English DT Article ID DRIVEN; FLOWS AB An approach to field modeling of fire phenomena in enclosures is presented. The conservation equations of mass, momentum and energy are calculated with sufficient temporal and spatial resolution to yield a truly three-dimensional, dynamic picture of the fire plume and its surroundings. The large-scale eddies are simulated directly and sub-grid scale motion is represented by a constant eddy viscosity. Efficient flow solving techniques make it possible to simulate fire scenarios using computational grids in excess of a million cells on modern workstations. Several examples of the methodology are presented. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP McGrattan, KB (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 TC 138 Z9 164 U1 0 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0379-7112 J9 FIRE SAFETY J JI Fire Saf. J. PD MAR PY 1998 VL 30 IS 2 BP 161 EP 178 DI 10.1016/S0379-7112(97)00041-6 PG 18 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA ZK853 UT WOS:000073370400003 ER PT J AU Davis, WD Levine, RRS AF Davis, WD Levine, RRS TI Computer simulation eliminates problem in aircraft carrier firefighting trainer SO FIRE TECHNOLOGY LA English DT Article C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Davis, WD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU NATIONAL FIRE PROTECTION ASSOC PI QUINCY PA ONE BATTERYMARCH PK, QUINCY, MA 02269 USA SN 0015-2684 J9 FIRE TECHNOL JI Fire Technol. PD MAR PY 1998 VL 34 IS 1 BP 89 EP 91 DI 10.1023/A:1015365000011 PG 3 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA ZG480 UT WOS:000073007900007 ER PT J AU Francis, RC Hare, SR Hollowed, AB Wooster, WS AF Francis, RC Hare, SR Hollowed, AB Wooster, WS TI Effects of interdecadal climate variability on the oceanic ecosystems of the NE Pacific SO FISHERIES OCEANOGRAPHY LA English DT Review ID NORTH-AMERICA; FISH PRODUCTION; WEST-COAST; SCALE; CALIFORNIA; FISHERIES; TRENDS AB A major reorganization of the North-east Pacific biota transpired following a climatic 'regime shift' in the mid 1970s. In this paper, we characterize the effects of interdecadal climate forcing on the oceanic ecosystems of the NE Pacific Ocean. We consider the concept of scale in terms of both time and space within the North Pacific ecosystem and develop a conceptual model to illustrate how climate variability is linked to ecosystem change. Next we describe a number of recent studies relating climate to marine ecosystem dynamics in the NE Pacific Ocean. These studies have focused on most major components of marine ecosystems - primary and secondary producers, forage species, and several levels of predators. They have been undertaken at different time and space scales. However, taken together, they reveal a more coherent picture of how decadal-scale climate forcing may affect the large oceanic ecosystems of the NE Pacific. Finally, we synthesize the insight gained from interpreting these studies. Several general conclusions can be drawn. 1 There are large-scale, low-frequency, and sometimes very rapid changes in the distribution of atmospheric pressure over the North Pacific which are, in turn, reflected in ocean properties and circulation. 2 Oceanic ecosystems respond on similar time and space scales to variations in physical conditions. 3 Linkages between the atmosphere/ocean physics and biological responses are often different across time and space scales. 4 While the cases presented here demonstrate oceanic ecosystem response to climate forcing, they provide only hints of the mechanisms of interaction. 5 A model whereby ecosystem response to specified climate variation can be successfully predicted will be difficult to achieve because of scale mismatches and nonlinearities in the atmosphere-ocean-biosphere system. C1 Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. Univ Washington, Int Pacific Halibut Commiss, Seattle, WA 98145 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. Univ Washington, Sch Marine Affairs, Seattle, WA 98105 USA. RP Francis, RC (reprint author), Univ Washington, Sch Fisheries, Box 357980, Seattle, WA 98195 USA. NR 48 TC 290 Z9 305 U1 6 U2 60 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 1998 VL 7 IS 1 BP 1 EP 21 DI 10.1046/j.1365-2419.1998.00052.x PG 21 WC Fisheries; Oceanography SC Fisheries; Oceanography GA ZR961 UT WOS:000074033700001 ER PT J AU Friedland, KD Hansen, LP Dunkley, DA AF Friedland, KD Hansen, LP Dunkley, DA TI Marine temperatures experienced by postsmolts and the survival of Atlantic salmon, Salmo salar L., in the North Sea area SO FISHERIES OCEANOGRAPHY LA English DT Article DE Atlantic salmon; growth; postmolt survival; recruitment; sea surface temperature; thermal habitat ID POST-SMOLT GROWTH; ONCORHYNCHUS-KISUTCH; CHINOOK SALMON; SEAWARD MIGRATION; BRITISH-COLUMBIA; VANCOUVER-ISLAND; ICELANDIC STOCKS; PACIFIC SALMON; SOCKEYE-SALMON; JUVENILE PINK AB The survival of two Atlantic salmon stocks that inhabit rivers confluent with the North Sea was examined in respect to historical distributions of sea surface water temperatures. The rivers Figgjo and North Esk are relatively small salmon rivers in southern Norway and eastern Scotland, respectively. Wild salmon smelts have been tagged in these rivers since 1965. Tag returns were used to evaluate the survival of salmon in the North Sea. Survival rates of one-sea-winter (1SW) and 2SW fish were correlated within stocks, as well as between stocks, Survival rates were compared with the areal extent of thermal habitat in the north-eastern Atlantic Ocean. A positive correlation was found between the area of 8-10 degrees C water in May and the survival of salmon. A reciprocal negative correlation was also found between survival and 5-7 degrees C water in the same month. An analysis of sea surface temperature distributions for periods of good vs. poor salmon survival showed that when cool surface waters dominate the Norwegian coast and North Sea during May, salmon survival has been poor. Conversely, when the 8 degrees C isotherm has extended northward along the Norwegian coast during May, survival has been good. The effect of water temperature distributions on the growth of postsmolts and other survival factors are discussed. C1 Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. Norwegian Inst Nat Res, N-7005 Trondheim, Norway. SOAEFD, Freshwater Fisheries Lab, Field Stn, Montrose DD10 8DL, Angus, Scotland. RP Friedland, KD (reprint author), Natl Marine Fisheries Serv, 166 Water St, Woods Hole, MA 02543 USA. NR 65 TC 73 Z9 73 U1 2 U2 12 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 1998 VL 7 IS 1 BP 22 EP 34 DI 10.1046/j.1365-2419.1998.00047.x PG 13 WC Fisheries; Oceanography SC Fisheries; Oceanography GA ZR961 UT WOS:000074033700002 ER PT J AU Cronin, G Wissing, KD Lodge, DM AF Cronin, G Wissing, KD Lodge, DM TI Comparative feeding selectivity of herbivorous insects on water lilies: aquatic vs. semi-terrestrial insects and submersed vs. floating leaves SO FRESHWATER BIOLOGY LA English DT Article ID GALERUCELLA-NYMPHAEAE COLEOPTERA; LILY BEETLE; CHEMICAL DEFENSES; LEAF PRODUCTION; PLANT DEFENSES; MACROPHYTES; INVERTEBRATES; CHRYSOMELIDAE; OVIPOSITION; COMMUNITIES AB 1. The rate of grazing damage experienced by submersed and floating leaves of water lilies (Nuphar variegata and Nymphaea odorata) was monitored in lakes in the Upper Peninsula of Michigan, U.S.A. Herbivores damaged 0.2-1.7% of the leaf surface of water lilies per day. These grazing rates differed between plant species, between submersed and floating leaves, and between lakes. Some leaves had more than 60% of their surface damaged and an overall mean of 16% damage occurred during the 2-3 week monitoring period of this study 2. Snapshot measurements of grazing damage on randomly collected submersed and floating leaves of Nuphar showed that submersed leaves were more damaged (11.0 +/- 1.6%, n = 84) than floating leaves (3.8 +/- 0.6%, n = 92). Overall, these 176 Nuphar leaves had 7.2% of their area damaged. 3. Five species of herbivorous insects were commonly found on water lilies (Nymphaeacea). One primarily aquatic insect (sensu Newman, 1991), a caddisfly larva (Trichoptera: Limniphilidae), had a generalized diet of water lilies, other macrophytes, algae, and detritus. Four of the five insects were from primarily terrestrial insect groups (Coleoptera and Diptera; 'secondary invaders', sensu Newman, 1991) and consumed only water lilies in food preference experiments. 4. The feeding preferences of the generalist trichopteran were altered when the macrophytes were freeze-dried, ground into a powder, and reconstituted in an alginate gel. This suggests that plant structure may be an important feeding determinant for this insect. In contrast, a specialist weevil preferred its host plant in choice assays, regardless of whether fresh tissue or reconstituted macrophytes were used, suggesting this insect cued on a unique, non-structural property of its host plant. 5. These results suggest that herbivory on freshwater macrophytes is of a similar magnitude to that on terrestrial plants. The findings of this study are consistent with the hypothesis that herbivorous insects of primarily terrestrial groups have a narrower diet breadth than insects of primarily aquatic groups. C1 Univ Notre Dame, Dept Biol Sci, Notre Dame, IN 46556 USA. RP Cronin, G (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NR 70 TC 35 Z9 36 U1 2 U2 18 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0046-5070 J9 FRESHWATER BIOL JI Freshw. Biol. PD MAR PY 1998 VL 39 IS 2 BP 243 EP 257 DI 10.1046/j.1365-2427.1998.00279.x PG 15 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA ZF319 UT WOS:000072885600005 ER PT J AU Beckman, BR Larsen, DA Moriyama, S Lee-Pawlak, B Dickhoff, WW AF Beckman, BR Larsen, DA Moriyama, S Lee-Pawlak, B Dickhoff, WW TI Insulin-like growth factor-I and environmental modulation of growth during smoltification of spring chinook salmon (Oncorhynchus tshawytscha) SO GENERAL AND COMPARATIVE ENDOCRINOLOGY LA English DT Article ID PARR-SMOLT TRANSFORMATION; GILTHEAD SEA BREAM; ATLANTIC SALMON; COHO SALMON; SEAWATER ADAPTATION; THYROID-HORMONES; RAINBOW-TROUT; MESSENGER-RNA; SALAR L; OSMOREGULATORY ACTIONS AB The relations among rearing environment, fish size, insulin-like growth factor-1, and smoltification were examined in yearling spring chinook salmon (Oncorhynchus tshawytscha). Juvenile chinook salmon were size-graded into small and large categories. Half of the fish in each group were reared at an increased temperature and feeding rate beginning in mid-February, resulting in four distinct treatment groups: large warm-water (LW), large cool-water (LC), small warm-water (SW), and small cool-water (SC). Increased temperature and feeding rate resulted in overall higher growth rates for the LW and SW groups. Temporal increases in insulin-like growth factor-I (IGF-I) were found in all groups through the spring. Plasma IGF-I levels were significantly higher in warm-water groups than in cool-water groups from late March through May. Size itself appeared to have little relation to plasma IGF-I levels. Simple regression showed a significant relation between plasma IGF-I and growth (P < 0.001, R-2 = 0.50). No differences were found between treatment groups in other physiological parameters assessed (plasma thyroxine, gill Na+-K+-ATPase, liver glycogen, body lipid). C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Integrat Fis Biol Program, Seattle, WA 98112 USA. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. RP Beckman, BR (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Integrat Fis Biol Program, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM beckman@fish.washington.edu NR 61 TC 106 Z9 110 U1 0 U2 11 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0016-6480 EI 1095-6840 J9 GEN COMP ENDOCR JI Gen. Comp. Endocrinol. PD MAR PY 1998 VL 109 IS 3 BP 325 EP 335 DI 10.1006/gcen.1997.7036 PG 11 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA ZA716 UT WOS:000072393800005 PM 9480740 ER PT J AU Lockwood, M Davis, CJ Onsager, TG Scudder, JD AF Lockwood, M Davis, CJ Onsager, TG Scudder, JD TI Modelling signatures of pulsed magnetopause reconnection in cusp ion dispersion signatures seen at middle altitudes SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GROUND-BASED OBSERVATIONS; INSTRUMENT AB It is shown that the open magnetosphere model can reproduce both the down-going and the up-going magnetosheath ions seen in the cusp and mantle regions by the Polar satellite at middle altitudes. ?he pass studied shows a series of discontinuities in the ion dispersion, most of which are shown to arise from pulses of magnetopause reconnection rate. A total of 9 pulses are detected in an interval estimated to be about 30 min long, giving a mean repetition period of about 3 min: they vary in length between 0.5 min and 3.5 min and are separated by periods of much slower reconnection of duration 1-3 min. One step is not as predicted for reconnection rate pulses but is explained in terms of compressive motions caused by a pulse of solar wind dynamic pressure. The reconnection site is found to be 16 +/- 3 R-E from the ionosphere along the separatrix field line, placing it at low latitudes on the dayside magnetopause. C1 Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. NOAA, Space Environm Ctr, RESE, Boulder, CO 80303 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. RP Lockwood, M (reprint author), Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. RI Lockwood, Mike/G-1030-2011; Scudder, Jack/D-8417-2013; Scott, Christopher/H-8664-2012 OI Lockwood, Mike/0000-0002-7397-2172; Scudder, Jack/0000-0001-7975-5630; Scott, Christopher/0000-0001-6411-5649 NR 11 TC 42 Z9 42 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 1998 VL 25 IS 5 BP 591 EP 594 DI 10.1029/98GL00185 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZA533 UT WOS:000072373800004 ER PT J AU Seitzinger, SP Kroeze, C AF Seitzinger, SP Kroeze, C TI Global distribution of nitrous oxide production and N inputs in freshwater and coastal marine ecosystems SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Review ID PRIMARY NITRITE MAXIMUM; NORTH-ATLANTIC OCEAN; NITRIFYING BACTERIA; CHESAPEAKE BAY; N2O PRODUCTION; ESTUARINE SEDIMENTS; SOUTHERN-CALIFORNIA; SEASONAL-VARIATION; NARRAGANSETT-BAY; RIVER ECOSYSTEM AB This study examines N(2)O emissions from aquatic environments globally, particularly as they are affected by anthropogenic activity. The global distribution of N(2)O production in rivers and estuaries was modeled as a function of nitrification and denitrification rates, which were related to external nitrogen (N) inputs. N loading rates were estimated as a function of environmental parameters in the watersheds using two existing models that we adapted for global databases. Model estimated export of dissolved inorganic nitrogen (DIN) by world rivers to estuaries in 1990 is 20.8 Tg N yr(-1); approximately 75% is estimated to be anthropogenic. DIN export to the Atlantic and Indian Oceans is similar (5.4 Tg N yr(-1) and 4.6 Tg N yr(-1), respectively); inputs to the Pacific are approximately 50% greater. China and southeast Asia account for over 50% of DIN export by world rivers. Globally, anthropogenic DIN export is predominately attributed to fertilizer N, followed by sewage and atmospheric deposition. About 8% of the total N inputs to the terrestrial environment can be accounted for as DIN export by rivers. Worldwide N(2)O emissions from rivers (55%), estuaries (11%), and continental shelves (33%) are calculated to be 1.9 Tg N yr(-1). For rivers and estuaries, approximately 90% of N(2)O emissions are in the northern hemisphere in line with the regional distribution of DIN export by rivers. China and India account for about 50% of N(2)O emissions from rivers and estuaries. About 1% of the N input from fertilizers, atmospheric deposition, and sewage to watersheds is lost as N(2)O in rivers and estuaries. Globally, rivers and estuaries could account for approximately 20% of the current global anthropogenic N(2)O emissions and are similar in magnitude to a number of previously identified sources including direct emissions of N(2)O from soils induced by anthropogenic N inputs. C1 Rutgers State Univ, Inst Marine & Coastal Sci, NOAA, Cooperat Marine Educ & Res Program, New Brunswick, NJ 08901 USA. Agr Univ Wageningen, Wageningen Inst Environm & Climate Res, NL-6700 HB Wageningen, Netherlands. RP Seitzinger, SP (reprint author), Rutgers State Univ, Inst Marine & Coastal Sci, NOAA, Cooperat Marine Educ & Res Program, 71 Dudley Rd, New Brunswick, NJ 08901 USA. EM sybil@imcs.rutgers.edu; carolien.kroeze@wimek.omkw.wau.nl NR 116 TC 292 Z9 330 U1 9 U2 100 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 1998 VL 12 IS 1 BP 93 EP 113 DI 10.1029/97GB03657 PG 21 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA ZB470 UT WOS:000072475200007 ER PT J AU Munroe, MJ Cooper, J Raymer, MG AF Munroe, MJ Cooper, J Raymer, MG TI Spectral broadening of stochastic light intensity-smoothed by a saturated semiconductor optical amplifier SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE amplifier noise; optical amplifiers; optical propagation in nonlinear media; optical saturation; optical signal processing; quantum-well devices; semiconductor optical amplifiers; spectroscopy ID LASERS AB We present calculations of the intensity smoothing of stochastic light by a semiconductor optical amplifier (SOA). We predict spectral changes of the light that are due to amplitude-to-phase coupling in the gain medium. The intensity smoothing of noisy optical signals with an SOA carries a penalty of spectral broadening (increased phase noise) that increases with increasing alpha parameter (linewidth enhancement factor). The spectral broadening also increases with increasing strength of the intensity fluctuations being smoothed. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80303 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Oregon, Oregon Ctr Opt, Eugene, OR 97403 USA. Univ Oregon, Dept Phys, Eugene, OR 97403 USA. RP Munroe, MJ (reprint author), Natl Inst Stand & Technol, Div Optoelect, 325 Broadway, Boulder, CO 80303 USA. NR 12 TC 19 Z9 19 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 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD MAR PY 1998 VL 34 IS 3 BP 548 EP 551 DI 10.1109/3.661465 PG 4 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA YZ366 UT WOS:000072247200022 ER PT J AU Diddams, SA Eaton, HK Zozulya, AA Clement, TS AF Diddams, SA Eaton, HK Zozulya, AA Clement, TS TI Characterizing the nonlinear propagation of femtosecond pulses in bulk media SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article; Proceedings Paper CT Meeting on Ultrafast Optics CY 1997 CL MONTEREY, CALIFORNIA DE nonlinear optics; optical propagation in nonlinear media; optical pulse measurements; ultrafast optics ID ULTRASHORT OPTICAL PULSES; GROUP-VELOCITY DISPERSION; REFRACTIVE-INDEX; PHASE; FIBERS; INTENSITY; RETRIEVAL; AIR AB Frequency-resolved optical gating is used to characterize the amplitude and phase of intense femtosecond pulses propagating in nonlinear dispersive media. The combined effects of group velocity dispersion (GVD) and third-order nonlinearity (n(2)) lead to rapid broadening and splitting of the pulses. We present measurements at 800 and 1200 mn and investigate the influence of the chirp of the input field. Measurements are compared with the predictions of one-and three-dimensional nonlinear Schrodinger equations. The influence of the Raman contribution to the nonlinear index of refraction is also examined theoretically. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RP Diddams, SA (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Clement, Tracy/A-8885-2008; Diddams, Scott/L-2819-2013 NR 41 TC 24 Z9 24 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 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD MAR-APR PY 1998 VL 4 IS 2 BP 306 EP 316 DI 10.1109/2944.686737 PG 11 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA ZV019 UT WOS:000074260200020 ER PT J AU Rufenach, CL Bates, JJ Tosini, S AF Rufenach, CL Bates, JJ Tosini, S TI ERS-1 scatterometer measurements - Part I: The relationship between radar cross section and buoy wind in two oceanic regions SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID TOWER-BASED MEASUREMENTS; HYDRODYNAMIC MODULATION; AIRBORNE SCATTEROMETERS; MODEL FUNCTION; STRESS; SPEED; WAVES; BACKSCATTER; SATELLITE; VECTOR AB Extensive European Remote Sensing Satellite (ERS-1) spacecraft scatterometer measurements were collocated within +/-25 km of buoy measurements at midlatitudes and in the equatorial Pacific during 1992-1994, Two different directional functional forms for the geophysical model were fit to these measurements described by cross section maxima aligned and offset, with respect to the mean wind direction, The two models exhibit fits with similar residuals for each of three years in the equatorial region, Thus, neither of these two model functions can convincingly be identified as more accurate than the other unless additional factors are considered, Nevertheless, the offset model results in an average directional offset near 10 degrees for each season during the three-year period; whereas, no such offset was inferred at midlatitudes, The cross section dependence on wind direction also exhibits another unexpected average property: a larger downwind compared to upwind cross section, A(10) approximate to -0.25 dB in the equatorial Pacific, This characteristic could be caused by a concentration of the short Bragg waves on the backside of the long wave crests, Both of these unexpected characteristics are likely related to a dominant systematic swell traveling nearly perpendicular to the prevailing easterly winds across the equatorial Pacific Ocean, The possible cross section dependence on wind stress and wind speed is due to long waves when adjusting the buoy measurements to a common height are discussed. C1 Univ Colorado, CIRES, Boulder, CO 80309 USA. NOAA, Climate Diagnost Ctr, Boulder, CO 80303 USA. RP Rufenach, CL (reprint author), Ocean Remote Sensing Inc, Longmont, CO 80501 USA. EM rufenach@tesser.com RI Bates, John/D-1012-2009 OI Bates, John/0000-0002-8124-0406 NR 53 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 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD MAR PY 1998 VL 36 IS 2 BP 603 EP 622 DI 10.1109/36.662742 PG 20 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA ZC333 UT WOS:000072566800021 ER PT J AU Zrnic, DS Ryzhkov, AV AF Zrnic, DS Ryzhkov, AV TI Observations of insects and birds with a polarimetric radar SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE radar polarimetry; scattering; weather radar ID BOUNDARY-LAYER; HAIL AB We present observations of biological scatterers with a polarimetric weather radar, The radar has a pencil beam, a high power, and a wavelength of 10 cm, It transmits horizontally and vertically polarized waves alternately, The available polarimetric variables are differential reflectivity, differential phase, and correlation coefficient between orthogonally polarized returns. Two types of biological scatterers, insects and birds, are contrasted, Observed polarimetric signatures of these are compared and explained with a simple scattering mode!. Finally, we discuss the implications of recognizing the biological scatterers' type and the size of birds. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73069 USA. RP Zrnic, DS (reprint author), NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. NR 19 TC 58 Z9 59 U1 3 U2 4 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 1998 VL 36 IS 2 BP 661 EP 668 DI 10.1109/36.662746 PG 8 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA ZC333 UT WOS:000072566800025 ER PT J AU Della Torre, E AF Della Torre, E TI A simplified vector Preisach model SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article DE accommodation; hysteresis Preisach modeling; magnetic viscosity; vector models ID MOVING MODEL; MEDIA AB Although scalar Preisach models have been increasingly accurate and efficient in describing material behavior, vector models, necessary to quantize complex magnetizing processes, are not as well developed, This paper presents a coupled vector model where the coupling is performed by a set of selection rules, after which the individual components can be calculated independently. This model reduces to a scalar model under appropriate conditions and the identification of its parameters is very straightforward. C1 Natl Inst Stand & Technol, Div Met, Magnet Mat Grp, Gaithersburg, MD 20899 USA. RP Della Torre, E (reprint author), Natl Inst Stand & Technol, Div Met, Magnet Mat Grp, Gaithersburg, MD 20899 USA. NR 14 TC 20 Z9 20 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 MAR PY 1998 VL 34 IS 2 BP 495 EP 501 DI 10.1109/20.661480 PN 2 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA ZA023 UT WOS:000072320300001 ER PT J AU Levine, J AF Levine, J TI Time synchronization using the Internet SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article ID PROBABILISTIC CLOCK SYNCHRONIZATION AB This paper discusses a new algorithm for synchronizing the clocks of networked computers using messages transmitted over the network itself. The design is based on a statistical model of the clock and the network, and uses this model to define the parameters of a frequency-lock loop which is used to discipline the local oscillator. The design was tested by synchronizing a standard workstation to a time server located 1200 km away; the time offset between the clock synchronized in this way and UTC is 2 ms rms. This analysis also can be used to design algorithms that provide lower accuracy at lower cost. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Levine, J (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 9 TC 7 Z9 7 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 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD MAR PY 1998 VL 45 IS 2 BP 450 EP 460 DI 10.1109/58.660155 PG 11 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA ZC597 UT WOS:000072597400018 PM 18244196 ER PT J AU Read, DT AF Read, DT TI Tension-tension fatigue of copper thin films SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE closed-loop testing; cyclic; displacement; endurance; force; piezoelectric; S-N curve; servo; strain; stress ID MECHANICAL-PROPERTIES AB Tension-tension, load-controlled fatigue results extending to over 100 000 cycles for electron-beam-evaporated copper are reported. The specimen is fabricated as a single tensile coupon with hundreds of grains across the width but only one or few through the thickness, supported on a silicon frame. These specimens had measured values of Young's modulus lower than literature values for bulk polycrystalline values, but had high values of the yield and ultimate strengths. Closed-loop feedback control of the piezoelectric actuators allowed load-controlled fatigue tests with a cycle duration of 15 s. Stress-endurance results for this set of copper films is reported and compared to previous results. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Read, DT (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. NR 17 TC 121 Z9 125 U1 2 U2 28 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD MAR PY 1998 VL 20 IS 3 BP 203 EP 209 DI 10.1016/S0142-1123(97)00080-7 PG 7 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA ZN036 UT WOS:000073601900002 ER PT J AU Vasconcellos, ECC Zerbetto, SC Zink, LR Evenson, KM AF Vasconcellos, ECC Zerbetto, SC Zink, LR Evenson, KM TI Laser lines and frequency measurements of fully deuterated isotopomers of methanol SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article DE (CD3OD)-C-12; (CD3OD)-C-13; fully deuterated isotopomers; new laser lines; far-infrared laser; frequency measurement; CO2 laser pump AB Fully deuterated isotopomers of methanol ((CD3OD)-C-12 and (CD3OD)-C-13) were optically pumped with a CO2 laser. Five new far-infrared laser lines were discovered in (CD3OD)-C-12 and 25 in (CD3OD)-C-13 in the range 43.697 to 719.426 mu m. The frequencies of these new and some previously reported laser lines, the pump offset, the relative polarization, the relative intensity, and the optimum pressure of operation were measured. C1 State Univ Campinas, UNICAMP, Dept Elect Quant, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Vasconcellos, ECC (reprint author), State Univ Campinas, UNICAMP, Dept Elect Quant, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. RI Inst. of Physics, Gleb Wataghin/A-9780-2017 NR 8 TC 6 Z9 6 U1 0 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD MAR PY 1998 VL 19 IS 3 BP 465 EP 473 DI 10.1023/A:1022511827416 PG 9 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA ZD480 UT WOS:000072690200009 ER PT J AU Chiang, MYM Chai, H AF Chiang, MYM Chai, H TI Finite element analysis of interfacial crack propagation based on local shear, part I - Near tip deformation SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article ID ELASTIC-PLASTIC ANALYSIS; CONTACT; LAYER AB Full-field, plane-strain elastoplastic solutions for an interface crack in adhesive bonds deforming in shear are obtained from a finite element analysis. The analysis, which considers very large strains and includes the effect of contact and friction between-the debonded interfaces, is particularized to a nearly elastic ideally-plastic interlayer obeying J(2) flow, which is sandwiched between either rigid or compliant substrates. Guided by experimental evidence, the analysis focuses on the interface ahead of the crack tip, where crack propagation occurs. The engineering shear strain at the crack tip along the interface, gamma, is characterized by a power-law singularity of the form gamma = K (x/h)(-delta), where h is the bond thickness, x is the horizontal axis originating from the crack tip and K and delta are the numerically obtained functions of bond-average shear strain, <(gamma)over bar>. The singular field under small-scale yielding (delta = 1) is maintained up to <(gamma)over bar> = 0.03 similar to 0.05, which is close to the yield Strain in shear of the adhesive (0.06). For larger remote shear strains, the strength of the singularity monotonically decreases with <(gamma)over bar>. This apparently new characteristic results from the interaction of the deformation held at the crack tip with the opposing interface of the bond. The distribution of shear strain ahead of the crack tip compares well with experimental results. The effect of interfacial friction appears to be significant only for relatively large loading (<(gamma)over bar> > 0.2). (C) 1997 Elsevier Science Ltd. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. Tel Aviv Univ, Dept Solid Mech Mat & Struct, IL-69978 Tel Aviv, Israel. RP Chiang, MYM (reprint author), NIST, Div Polymers, BLDG 224,Rm A, Gaithersburg, MD 20899 USA. NR 23 TC 6 Z9 6 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD MAR-APR PY 1998 VL 35 IS 9-10 BP 799 EP + DI 10.1016/S0020-7683(97)00085-1 PG 14 WC Mechanics SC Mechanics GA YL887 UT WOS:000071004300003 ER PT J AU Chai, H Chiang, MYM AF Chai, H Chiang, MYM TI Finite element analysis of interfacial crack propagation based on local shear, part II - Fracture SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article ID CRITERION AB The mechanics of fracture of a stably extending interface crack in polymeric adhesive bonds undergoing Very large shear deformation is studied using a rate-dependent finite element analysis. Plane-strain and J(2) plasticity conditions are considered. Based on recent experimental observations, it is assumed that the local engineering shear strain at a certain distance (i.e. for the polymer adhesive studied, approximately a tenth bond thickness) straight ahead of the crack tip remains constant during the crack propagation. This critical strain is rate dependent, being a function of the crack velocity. The proposed fracture criterion is applied to several experimental crack growth histories pertaining to different specimen geometries, bond thicknesses and crack velocities. Although the analysis is highly sensitive to rate effects and other material characteristics, the comparison is generally reasonably successful. The analysis also provides quantitative insight into the mechanics of other failure modes observed in the experiments. In particular, the growth of a detrimental microdebond which is formed several bond thicknesses ahead of the crack tip seem to be controlled by the bond-normal tensile stress while hydrostatic tensile stresses appear responsible for the development of a kink or a large void at the crack lip which temporarily arrests the crack. All these and other failure modes are activated under large strains, which manifests the important rule of plasticity in the fracture of polymeric joints. (C) 1997 Published by Elsevier Science Ltd. C1 Tel Aviv Univ, Dept Solid Mech Mat & Struct, IL-69978 Tel Aviv, Israel. NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Chai, H (reprint author), Tel Aviv Univ, Dept Solid Mech Mat & Struct, IL-69978 Tel Aviv, Israel. NR 12 TC 12 Z9 12 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD MAR-APR PY 1998 VL 35 IS 9-10 BP 815 EP + DI 10.1016/S0020-7683(97)00086-3 PG 14 WC Mechanics SC Mechanics GA YL887 UT WOS:000071004300004 ER PT J AU Berg, RF Zimmerli, GA Moldover, MR AF Berg, RF Zimmerli, GA Moldover, MR TI Measurement of microkelvin temperature differences in a critical-point thermostat SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE critical point; temperature control; temperature gradients; thermostat AB The density of a pure fluid near its critical point is extremely sensitive to temperature gradients. In the absence of gravity, this effect limits the fluid's homogeneity. For example, at 0.6 mK above the critical temperature, the microgravity experiment Critical Viscosity of Xenon (CVX) can allow temperature differences no larger than 0.2 mu K, corresponding to a gradient of 10(-5) K.m(-1). The CVX thermostat, which consists of a thick-walled copper cell contained within three concentric aluminum shells, was designed to achieve such a small temperature gradient. However, asymmetries not included in the thermostat's model could degrade the thermostat's performance. Therefore we measured the temperature gradient directly with a miniature commercial thermoelectric cooler consisting of 66 semiconductor thermocouples. We checked the results with a half bridge consisting of two matched thermistors. The measurement was made along a thin-walled stainless-steel cell whose conductance was much lower than that of the copper cell, thus "amplifying" the temperature differences by a factor of 60. When the thermostat was controlled at a constant temperature, the steel cell's static temperature difference was 5 +/- 1 mu K. (The value inferred for the copper cell is 0.08 mu K.) Ramping the thermostat's temperature at a rate of 1 x 10(-5) K.s(-1) increased the temperature difference to 0.36 mK. These results demonstrate the feasibility of achieving extremely low temperature gradients. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NYMA Inc, Engn Serv Div, Brook Pk, OH 44142 USA. RP Berg, RF (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Moldover, Michael/E-6384-2013 NR 6 TC 8 Z9 8 U1 0 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD MAR PY 1998 VL 19 IS 2 BP 481 EP 490 DI 10.1023/A:1022521712860 PG 10 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA ZY912 UT WOS:000074675100014 ER PT J AU Josell, D Cezairliyan, A Bonevich, JE AF Josell, D Cezairliyan, A Bonevich, JE TI Thermal diffusion through multilayer coatings: Theory and experiment SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE aluminum oxide; laser pulse; molybdenum; multilayer; thermal barrier coatings; thermal diffusion; thermal diffusivity AB Thermal diffusion through aluminum oxide/molybdenum multilayers (10, 20, and 40 bilayers on molybdenum substrates) was studied through thermal pulse experiments. In these experiments, a thermal pulse (< 50 ns) was delivered by a laser to the front surface of the specimen and the resulting temperature transient on the rear surface, typically several degrees, was recorded. An integral solution for the equations governing heat transfer was used to relate experimental results to the thermal resistance of the interfaces. Experimental studies were conducted at temperatures from 950 to 1150 degrees C, relevant to thermal. barrier applications. Significant densification of the oxide layers was observed during the experiments at all but the lowest temperature. As a result of these experiments, an upper bound has been placed on the interface thermal resistance. C1 NIST, Div Met, Gaithersburg, MD 20899 USA. RP Josell, D (reprint author), NIST, Div Met, Gaithersburg, MD 20899 USA. NR 10 TC 7 Z9 7 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD MAR PY 1998 VL 19 IS 2 BP 525 EP 535 DI 10.1023/A:1022529914677 PG 11 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA ZY912 UT WOS:000074675100018 ER PT J AU Schulz, JP Dumenil, L Polcher, J Schlosser, CA Xue, Y AF Schulz, JP Dumenil, L Polcher, J Schlosser, CA Xue, Y TI Land surface energy and moisture flares: Comparing three models SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID GENERAL-CIRCULATION MODELS; BIOSPHERE MODEL; ECMWF MODEL; CLIMATE; SENSITIVITY; RESISTANCE; ATMOSPHERE; SCHEMES; SIB AB Three different land surface schemes that mt designed for use in atmospheric general circulation models are compared. They were run in offline mode with identical atmospheric forcing values that were observed at Cabauw. This procedure allows one to analyze differences in the simulations that are not caused by different atmospheric conditions and to relate them to certain model characteristics. The intercomparison shows that the models produced similar results for surface temperature and total net radiation, which are also in good agreement with the observations. But they underestimate latent heat flux and overestimate sensible heat flux in summer. Differences in the components of energy and hydrological cycle as simulated by the schemes can be related to differences in model structures. The calculation of the surface temperature is of major importance, particularly on a diurnal timescale. Depending on the scheme chosen, the simulated surface temperature is closer to the observed radiative surface temperature or the observed soil temperature at a depth of a few centimeters. Ii a land surface scheme Is going to be coupled to an atmospheric model, this needs to be considered; The simulation of the surface energy fluxes can be improved by careful calibration of the relevant parameters according to the conditions at the observational site. The stomatal resistance was found to be an essential parameter in determining the evolution of evapotranspiration for the Cabauw simulations. C1 Max Planck Inst Meteorol, D-20146 Hamburg, Germany. CNRS, Meteorol Dynam Lab, Paris, France. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. Ctr Ocean Land Atmosphere Studies, Calverton, MD USA. RP Schulz, JP (reprint author), Max Planck Inst Meteorol, Bundesstr 55, D-20146 Hamburg, Germany. NR 24 TC 21 Z9 22 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD MAR PY 1998 VL 37 IS 3 BP 288 EP 307 DI 10.1175/1520-0450(1998)037<0288:LSEAMF>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YY532 UT WOS:000072157300004 ER PT J AU Johnson, W AF Johnson, W TI Ultrasonic damping in pure aluminum at elevated temperatures SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTROMAGNETIC-ACOUSTIC TRANSDUCTION; DEPENDENCE; SPECTROSCOPY AB Ultrasonic resonant damping was measured in polycrystalline 99.999% pure aluminum spheres between 22 and 465 degrees C at frequencies between 0.4 and 2.0 MHz. In fully annealed samples, the damping increases monotonically with temperature in a manner similar to that reported in numerous lower-frequency studies of a variety of materials. However, the activation energy of this increase is significantly less than values reported for aluminum at lower frequencies, and the frequency dependence is much different; these facts suggest that a different physical mechanism dominates the damping in the higher frequency range. The dependences on temperature, frequency, and vibrational amplitude are consistent with an anelastic dislocation mechanism. During recovery and recrystallization of cold-worked material, the damping drops irreversibly with a time dependence matching that expected for the dislocation density. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Johnson, W (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, 325 Broadway, Boulder, CO 80303 USA. NR 29 TC 12 Z9 12 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAR 1 PY 1998 VL 83 IS 5 BP 2462 EP 2468 DI 10.1063/1.366633 PG 7 WC Physics, Applied SC Physics GA YZ942 UT WOS:000072310700012 ER PT J AU Field, PR Rishbeth, H Moffett, RJ Idenden, DW Fuller-Rowell, TJ Millward, GH Aylward, AD AF Field, PR Rishbeth, H Moffett, RJ Idenden, DW Fuller-Rowell, TJ Millward, GH Aylward, AD TI Modelling composition changes in F-layer storms SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID GEOMAGNETIC STORMS; THERMOSPHERE; IONOSPHERE; REGION; DISTURBANCE; LATITUDE; PATTERNS; MIDDLE; PHASE AB A coupled thermosphere-ionosphere-plasmasphere model CTIP is used to simulate storm changes in the ionosphere. The simulations cover a period of 72 hours, starting with imposed high-latitude energy inputs (particle precipitation and electric fields) that represent a moderately severe geomagnetic storm (K-p 5) lasting for 12 h. Equinox and solstice conditions are studied. We give particular attention to comparing changes in peak electron density, N(m)F2, to those of the [O/N-2] concentration ratio of the neutral air. During the first few hours of the storm, large perturbations are produced by strong meridional winds. After that initial phase, we find that the changes of N(m)F2 and of [O/N-2] ratio correspond closely, the composition changes being produced by the thermospheric "storm circulation", as in the "composition bulge" theory of Fuller-Rowell et al. (1994). The simulations reproduce the general form of the seasonal variations in the changes of N(m)F2 at mid-latitudes as derived from worldwide ionosonde data. Some storm effects at sub-auroral latitudes are caused by movement and infilling of the ionospheric trough. We conclude that the composition change theory accounts for the major features of F-layer storm behaviour at midlatitudes. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. Univ Sheffield, Sch Math & Stat, Sheffield S3 7RH, S Yorkshire, England. Univ Colorado, CIRES, Boulder, CO 80303 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. UCL, Atmospher Phys Lab, London W1P 7PP, England. RP Field, PR (reprint author), Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. EM hr@phys.soton.ac.uk RI Field, Paul/B-1692-2009 OI Field, Paul/0000-0001-8528-0088 NR 32 TC 61 Z9 62 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 EI 1879-1824 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD MAR PY 1998 VL 60 IS 5 BP 523 EP 543 DI 10.1016/S1364-6826(97)00074-6 PG 21 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA ZV282 UT WOS:000074289000003 ER PT J AU Wallace, WE Tan, NCB Wu, WL Satija, S AF Wallace, WE Tan, NCB Wu, WL Satija, S TI Mass density of polystyrene thin films measured by twin neutron reflectivity SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GLASS-TRANSITION TEMPERATURE; X-RAY REFLECTIVITY; POLYMER MELT; SURFACES; INTERFACES; DEPENDENCE; SIMULATION; DYNAMICS; SILICON; WALL AB Neutron reflectivity measurements on polystyrene thin films (6.5-79.0 nm thick) supported on silicon substrates indicate that the mass density is near the bulk value regardless of film thickness. To account for possible inaccuracies arising from sample misalignment, reflectivity measurements were made both from the free-surface and silicon-substrate sides of the thin film, a method termed twin reflectivity. For films spin coated on the hydrogen-terminated silicon surface the relative uncertainty in the density measurement was on the order of 1%, but for films spin coated onto the silicon native-oxide surface the analysis was more difficult because of subtleties in data fitting due to the oxide layer. Nevertheless, within the limits of greater uncertainty, these films also showed no systematic change in density with thickness. (C) 1998 American Institute of Physics. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Wallace, WE (reprint author), NIST, Div Polymers, Bldg 224,Room B320, Gaithersburg, MD 20899 USA. EM william.wallace@nist.gov NR 40 TC 61 Z9 62 U1 1 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 1 PY 1998 VL 108 IS 9 BP 3798 EP 3804 DI 10.1063/1.475769 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YZ048 UT WOS:000072215000046 ER PT J AU Cullather, RI Bromwich, DH Van Woert, ML AF Cullather, RI Bromwich, DH Van Woert, ML TI Spatial and temporal variability of Antarctic precipitation from atmospheric methods SO JOURNAL OF CLIMATE LA English DT Article ID WATER-VAPOR TRANSPORT; SEA-LEVEL PRESSURE; MASS-BALANCE; SOUTHERN-HEMISPHERE; SNOW ACCUMULATION; MOISTURE BUDGET; GLOBAL ANALYSES; ECMWF ANALYSES; ICE SHEETS; CLIMATE AB The spatial and temporal variability of net precipitation (precipitation minus evaporation/sublimation) for Antarctica derived from the European Centre for Medium-Range Weather Forecasts operational analyses via the atmospheric moisture budget is assessed in comparison to a variety of glaciological and meteorological observations and datasets. For the 11-yr period 1985-95, the average continental value is 151 mm yr(-1) water equivalent. Large regional differences with other datasets are identified, and the sources of error are considered. Interannual variability in the Southern Ocean storm tracks is found to be an important mechanism for enhanced precipitation minus evaporation (P - E) in both east and west Antarctica. In relation to the present findings, an evaluation of the rawinsonde method for estimating net precipitation in east Antarctica is conducted. Estimates of P - E using synthetic rawinsondes derived from the analyses are found to compare favorably to glaciological estimates. A significant upward trend of 2.4 mm yr(-1) is found for the Antarctic continent that is consistent with findings from the National Centers for Environmental Prediction, formerly the National Meteorological Center, and the National Center for Atmospheric Research Reanalysis precipitation dataset. Despite large regional discrepancies, the general agreement on the main features of Antarctic precipitation between studies suggests that a threshold has been reached, where the assessment of the smaller terms including evaporation/sublimation and drift snow loss is required to explain the differences. C1 Ohio State Univ, Byrd Polar Res Ctr, Polar Meterol Grp, Columbus, OH 43210 USA. NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD USA. RP Bromwich, DH (reprint author), Ohio State Univ, Byrd Polar Res Ctr, Polar Meterol Grp, Columbus, OH 43210 USA. EM bromwich@polarmetl.mps.ohio-state.edu RI Bromwich, David/C-9225-2016 NR 75 TC 85 Z9 90 U1 2 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAR PY 1998 VL 11 IS 3 BP 334 EP 367 DI 10.1175/1520-0442(1998)011<0334:SATVOA>2.0.CO;2 PG 34 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF338 UT WOS:000072887500003 ER PT J AU Mo, KC Higgins, RW AF Mo, KC Higgins, RW TI Tropical influences on California precipitation SO JOURNAL OF CLIMATE LA English DT Article ID OUTGOING LONGWAVE RADIATION; NORTHERN HEMISPHERE WINTER; CENTRAL UNITED-STATES; SOUTHERN OSCILLATION; GEOPOTENTIAL HEIGHT; NASA/DAO REANALYSES; MOISTURE BUDGET; NCEP/NCAR; RAINFALL; TELECONNECTIONS AB Atmospheric circulation anomalies and hydrologic processes associated with California wet and dry events were examined during Northern Hemisphere winter. The precipitation anomaly over the west coast of North America shows a north-south three-cell pattern. Heavy precipitation in California is accompanied by dry conditions over Washington, British Columbia, and along the southeastern coast of Alaska and reduced precipitation over the subtropical eastern Pacific. The inverse relationship between California and the Pacific Northwest is supported by the transport of moisture flux. During wet events, the southern branch of moisture flux transport strengthens and brings moisture from the North Pacific to California, hence enhanced rainfall. Strengthened moisture flux transport northward to the area north of Washington is consistent with suppressed rainfall in California. The local precipitation anomaly pattern in the eastern tropical Pacific just north of the equator has a large influence on precipitation events in California. The enhanced precipitation generates strong rising motion. The associated sinking motion is located over California. Strong sinking motion and strong upper-level convergence favor dry conditions in California. Conversely, suppressed rainfall in the eastern Pacific is associated with above-normal precipitation in California. Precipitation in California is likely below normal during cold ENSO events. When convection in the central Pacific is enhanced, California has heavy precipitation if rainfall in the subtropical eastern Pacific is suppressed. In addition to ENSO, precipitation in California is also modulated by the tropical intraseasonal oscillation. Wet (dry) events are favored during the phase of the oscillation associated with enhanced convection near 150 degrees E (120 degrees E) in the tropical Pacific. C1 NOAA, Natl Weather Serv, NCEP, Climate Predict Ctr, Washington, DC 20233 USA. RP Mo, KC (reprint author), NOAA, Natl Weather Serv, NCEP, Climate Predict Ctr, 4700 Silver Hill Rd,Stop 9910, Washington, DC 20233 USA. NR 25 TC 92 Z9 95 U1 1 U2 11 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAR PY 1998 VL 11 IS 3 BP 412 EP 430 DI 10.1175/1520-0442(1998)011<0412:TIOCP>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF338 UT WOS:000072887500007 ER PT J AU Kim, SC Chen, J Park, K Choi, JK AF Kim, SC Chen, J Park, K Choi, JK TI Coastal surges from extratropical storms on the west coast of the Korean Peninsula SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE extratropical storms; storm surges; coastal hazards; Korean Peninsula; Yellow Sea AB Coastal surges along the west coast of the Korean Peninsula from extratropical storms were investigated using tide gage observations for one year and numerical model hindcasting. Positive surges were associated with smaller scale meteorological forcing than negative surges. Spatial and temporal variations among different locations characterized typical surge propagation from south to north along the west coast and from west to east across the Yellow Sea. Forecasting is feasible with meteorological forcing input with around 1 degrees-1.5 degrees spatial and 6 hourly temporal resolutions. C1 Virginia Inst Marine Sci, Coll William & Mary, Sch Marine Sci, Gloucester Point, VA 23062 USA. NOAA, Natl Weather Serv, Silver Spring, MD 20910 USA. Inha Univ, Dept Oceanog, Nam Ku, Inchon, South Korea. Univ Colorado, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA. RP Kim, SC (reprint author), Virginia Inst Marine Sci, Coll William & Mary, Sch Marine Sci, Gloucester Point, VA 23062 USA. NR 8 TC 1 Z9 1 U1 0 U2 2 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD SPR PY 1998 VL 14 IS 2 BP 660 EP 666 PG 7 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA ZJ198 UT WOS:000073189300026 ER PT J AU Xu, HHK Smith, DT Jahanmir, S Romberg, E Kelly, JR Thompson, VP Rekow, ED AF Xu, HHK Smith, DT Jahanmir, S Romberg, E Kelly, JR Thompson, VP Rekow, ED TI Indentation damage and mechanical properties of human enamel and dentin SO JOURNAL OF DENTAL RESEARCH LA English DT Article DE crack; dentino-enamel junction; enamel rod; fracture toughness; tooth orientation; modulus ID FRACTURE PROPERTIES; MATERIAL-REMOVAL; TOUGHNESS; HARDNESS; MICROSTRUCTURE; CERAMICS; JUNCTION; ALUMINA AB Understanding the mechanical properties of human teeth is important to clinical tooth preparation and to the development of "tooth-like" restorative materials. Previous studies have focused on the macroscopic fracture behavior of enamel and dentin. In the present study, we performed indentation studies to understand the microfracture and deformation and the microcrack-microstructure interactions of teeth. It was hypothesized that crack propagation would be influenced by enamel rods and the dentino-enamel junction (DEJ), and the mechanical properties would be influenced by enamel rod orientation and tooth-to-tooth variation. Twenty-eight human third molars were used for the measurement of hardness, fracture toughness, elastic modulus, and energy absorbed during indentation. We examined the effect of enamel rod orientation by propagating cracks in the occlusal surface, and in the axial section in directions parallel and perpendicular to the occlusal surface. The results showed that the cracks in the enamel axial section were significantly longer in the direction perpendicular to the occlusal surface than parallel. The cracks propagating toward the DEJ were always arrested and unable to penetrate dentin. The fracture toughness of enamel was not single-valued but varied by a factor of three as a function of enamel rod orientation. The elastic modulus of enamel showed a significant difference between the occlusal surface and the axial section. It is concluded that the cracks strongly interact with the DEJ and the enamel rods, and that the mechanical properties of teeth are functions of microstructural orientations; hence, single values of properties (e.g., a single toughness value or a single modulus value) should not be used without information on microstructural orientation. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Univ Maryland, Sch Dent, Dept Oral Hlth Care Delivery, Stat Grp, Baltimore, MD 21201 USA. USN, Sch Dent, Dept Prosthodont, Bethesda, MD 20889 USA. Univ Maryland, Sch Dent, Dept Restorat Dent, Baltimore, MD 21201 USA. Univ Med & Dent New Jersey, Dept Orthodont, Newark, NJ 07103 USA. RP Xu, HHK (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Bldg 224,Room A-153, Gaithersburg, MD 20899 USA. RI Smith, Douglas/I-4403-2016; OI Smith, Douglas/0000-0002-9358-3449; Thompson, Van P/0000-0003-0033-0344 FU NIDCR NIH HHS [1 P01DE10976-01A1] NR 24 TC 302 Z9 315 U1 10 U2 48 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD MAR PY 1998 VL 77 IS 3 BP 472 EP 480 PG 9 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YZ958 UT WOS:000072312300006 PM 9496920 ER PT J AU Vogel, GL Zhang, Z Carey, CM Ly, A Chow, LC Proskin, HM AF Vogel, GL Zhang, Z Carey, CM Ly, A Chow, LC Proskin, HM TI Composition of plaque and saliva following a sucrose challenge and use of an alpha-tricalcium-phosphate-containing chewing gum SO JOURNAL OF DENTAL RESEARCH LA English DT Article DE gums; caries; plaque; saliva; enamel saturation ID CARIES-POSITIVE INDIVIDUALS; CALCULUS FORMATION; DENTAL-CARIES; WHOLE SALIVA; FLOW-RATE; CALCIUM; FLUID; PH; ENAMEL; SATURATION AB Calcium phosphate concentrations in plaque, plaque fluid, and saliva play an important role in caries prevention. In this study, we used a microanalytical technique to examine the anticaries potential of a 2.5% (mass fraction) alpha-tricalcium-phosphate-fortified experimental gum by measuring the pH, free and total calcium, and total phosphate in plaque fluid, whole plaque, and saliva, and centrifuged saliva from 14 subjects who (1) accumulated plaque for 48 hours, (2) fasted overnight, (3) rinsed for 1 min with sucrose, and (4) chewed a control or experimental gum for 15 min. From these data, the hydroxyapatite (HAp) ion activity products (IAP(HAp)) of saliva and plaque fluid were calculated as a measure of tooth mineral saturation. Results, compared with those of the control gum, show significant increases in pH and in free calcium and phosphate concentrations in plaque fluid and saliva when the experimental gum was chewed following sucrose ingestion. These increases result in a rise in fluid saturation with respect to tooth mineral that, for plaque fluid, nearly cancels the decrease seen with the control gum after the sucrose rinse. This suggests that the experimental gum may be more effective than a conventional gum in ameliorating the cariogenic effects of sucrose. Similar statistically significant increases were also seen in the total calcium content of the plaque fluid, centrifuged saliva, whole saliva, and whole plaque, and in the total phosphate of whole plaque and whole saliva. These results suggest that the deposition of a mineral reservoir in plaque and saliva by the experimental gum may help resist future cariogenic challenges. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. Howard M Proskin & Associates, Rochester, NY 14618 USA. RP Vogel, GL (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Room A 153,Bldg 224, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [DE05354, DE10840] NR 43 TC 23 Z9 24 U1 0 U2 1 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD MAR PY 1998 VL 77 IS 3 BP 518 EP 524 PG 7 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YZ958 UT WOS:000072312300011 PM 9496925 ER PT J AU Lowery, TA AF Lowery, TA TI Modelling estuarine eutrophication in the context of hypoxia, nitrogen loadings, stratification and nutrient ratios SO JOURNAL OF ENVIRONMENTAL MANAGEMENT LA English DT Article DE estuarine; eutrophication; modelling; nutrients; nitrogen; Gulf of Mexico ID COASTAL AB Estuarine eutrophication is a serious ecological and economic problem. Hypoxic waters resulting from decomposing phytoplankton in stratified bottom-waters are often associated with estuarine eutrophication, with the degree of the phytoplankton accumulation and subsequent decomposition corresponding to the phytoplankton's density in the overlying water: In general, high phytoplankton densities occur when nutrient availability is high enough to maintain the phytoplankton population. High nutrient availabilities generally result from high nutrient loads entering estuaries from their watersheds. Therefore, the cc-occurrence of stratified bottom-waters and high nutrient loadings predisposes estuaries to developing hypoxic bottom waters. This paper presents a multinominal logistic regression model that predicts the status of estuaries as normoxic, borderline hypoxic, hypoxic and severely hypoxic based on nitrogen loadings, salinity stratifications and 'phosphorus to nitrogen' load ratios. The model was applied to 10 US Gulf of Mexico estuaries and it correctly assigned eight of the 10 estuaries to their correct eutrophication status. Summaries of each estuary's probabilities for being normoxic, borderline hypoxic, hypoxic or severely hypoxic are presented along with their modelled responses to changes in nutrient loadings. Other model results include nutrient loading reductions associated with moving hypoxic and severely hypoxic estuaries into the normoxic and borderline status. This estuarine eutrophication model follows previously developed eutrophication models for lakes which were based on similar premises and have been successfully used to develop management policies. The estuarine eutrophication modelling approach provides a platform for evaluating nutrient reduction management strategies in the context of an estuary's modelled response to proposed nutrient reductions. Therefore, the modelling approach presented here is offered in support of developing management policies concerning estuarine eutrophication. (C) 1998 Academic Press Limited. C1 NOAA, Strateg Ocean Environm Assessments Div, Silver Spring, MD 20910 USA. RP Lowery, TA (reprint author), NOAA, Strateg Ocean Environm Assessments Div, N-ORCA 1,SSMC4,1305 EW Highway, Silver Spring, MD 20910 USA. NR 33 TC 12 Z9 14 U1 1 U2 23 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0301-4797 EI 1095-8630 J9 J ENVIRON MANAGE JI J. Environ. Manage. PD MAR PY 1998 VL 52 IS 3 BP 289 EP 305 DI 10.1006/jema.1998.0180 PG 17 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZT270 UT WOS:000074067700007 ER PT J AU Link, J Hoff, MH AF Link, J Hoff, MH TI Relationships of Lake Herring (Coregonus artedi) gill raker characteristics to retention probabilities of zooplankton prey SO JOURNAL OF FRESHWATER ECOLOGY LA English DT Article ID ALOSA-PSEUDOHARENGUS; PLANKTIVOROUS FISH; FEEDING FISH; MORPHOLOGY; PREDATION; SUPERIOR; ALEWIFE AB We measured morphometric and meristic parameters of gill rakers from the first gill arch of 36 adult lake herring (Coregonus artedi) from Lake Superior that ranged in length from 283-504 mm. These data, coupled with the mean of the smallest two body dimensions (length, width, or breadth) of various zooplankton prey, allowed us to calculate retention probabilities for zooplankton taxa that are common in Lake Superior. The mean of the smallest two body dimensions was positively correlated with body length for cladocerans and copepods. The large cladoceran, Daphnia g. mendotae, is estimated to be retained at a greater probability (74%) than smaller cladocerans (18%-38%). The same is true for the large copepod, Limnocalanus macrurus (60%), when compared to smaller copepods (6-38%). Copepods have a lower probability of being retained than cladocerans of similar length. Lake herring gill rakers and total filtering area are also positively correlated with fish total length. These data provide further evidence that lake herring are primarily planktivores in Lake Superior, and our data show that lake herring can retain a broad range of prey sizes. C1 Michigan Technol Univ, Dept Biol Sci, Houghton, MI 49931 USA. US Geol Survey, Great Lakes Sci Ctr, Lake Superior Biol Stn, Ashland, WI 54806 USA. RP Link, J (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 35 TC 16 Z9 16 U1 1 U2 7 PU OIKOS PUBL INC PI LA CROSSE PA PO BOX 2558, LA CROSSE, WI 54601 USA SN 0270-5060 J9 J FRESHWATER ECOL JI J. Freshw. Ecol. PD MAR PY 1998 VL 13 IS 1 BP 55 EP 65 DI 10.1080/02705060.1998.9663591 PG 11 WC Ecology; Limnology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA YZ929 UT WOS:000072309100008 ER PT J AU Fuller-Rowell, TJ AF Fuller-Rowell, TJ TI The "thermospheric spoon": A mechanism for the semiannual density variation SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article AB A mechanism is proposed to explain the cause off the global, semiannual thermospheric density variation. It is suggested that the global-scale, interhemispheric circulation at solstice acts like a huge turbulent eddy in mixing the major thermospheric species. The effect causes less diffusive separation of the species at solstice, which tends to raise molecular nitrogen and oxygen densities and reduce atomic oxygen density, compared with equinox. The increased mean mass, at solstice, reduces the density scale height at a given altitude. This "compression" of the atmosphere at solstice can explain the mean amplitude of the semiannual density anomaly. Since ionospheric loss rates are affected by neutral composition, the proposed mechanism also leads to a similar ionospheric density variation. C1 NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Fuller-Rowell, TJ (reprint author), NOAA, Space Environm Ctr, R-E-SE,325 Broadway, Boulder, CO 80303 USA. NR 18 TC 89 Z9 91 U1 3 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1998 VL 103 IS A3 BP 3951 EP 3956 DI 10.1029/97JA03335 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZA782 UT WOS:000072401200001 ER PT J AU Hoelzel, AR Dahlheim, M Stern, SJ AF Hoelzel, AR Dahlheim, M Stern, SJ TI Low genetic variation among killer whales (Orcinus orca) in the eastern North Pacific and genetic differentiation between foraging specialists SO JOURNAL OF HEREDITY LA English DT Article ID MITOCHONDRIAL-DNA; POPULATIONS; TRANSIENT; BEHAVIOR; ALASKA AB Killer whales from the coastal waters off California through Alaska were compared for genetic variation at three nuclear DNA markers and sequenced for a total of 520 bp from the mitochondrial control region. Two putative sympatric populations that range throughout this region were compared. They can be distinguished by social and foraging behavior and are known as "residents" and "transients." We found low levels of variation within populations compared to other cetacean species. Comparisons between fish (resident) versus marine mammal (transient) foraging specialists indicated highly significant genetic differentiation at both nuclear and mitochondrial loci. This differentiation is at a level consistent with intraspecific variation. A comparison between two parapatric resident populations showed a small but fixed mtDNA haplotype difference. Together these data suggest low levels of genetic dispersal between foraging specialists and a pattern of genetic differentiation consistent with matrifocal population structure and small effective population size. C1 NMFS, Natl Marine Mammal Lab, Seattle, WA USA. Texas A&M Univ, Marine Mammal Res Program, Galveston, TX USA. NCI, Viral Carcinogenesis Lab, Frederick, MD 21701 USA. RP Univ Durham, Dept Biol Sci, South Rd, Durham DH1 3LE, England. NR 32 TC 155 Z9 162 U1 6 U2 48 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1503 EI 1465-7333 J9 J HERED JI J. Hered. PD MAR-APR PY 1998 VL 89 IS 2 BP 121 EP 128 DI 10.1093/jhered/89.2.121 PG 8 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA ZK793 UT WOS:000073364100002 PM 9542159 ER PT J AU Johnson, GC AF Johnson, GC TI Deep water properties, velocities, and dynamics over ocean trenches SO JOURNAL OF MARINE RESEARCH LA English DT Article ID NORTH PACIFIC; ABYSSAL CIRCULATION; DRIVEN CIRCULATION; BASIN; TOPOGRAPHY; ATLANTIC; SECTIONS; CURRENTS; FLOW AB Observations of water properties and deep currents over several trenches in the Pacific Ocean central basins give consistent evidence for recent ventilation of water below the trench sills and cyclonic sense of circulation over the trenches. A dynamical argument for this pattern is advanced. First, a review of previous analyses of hydrographic data shows that the trenches are well ventilated by dense bottom water, that within the trenches this bottom water generally spreads away from its source, and that a cyclonic sense of circulation is suggested over some trenches. Then, this cyclonic sense of circulation over the trenches is further documented using deep current meter and float data. Finally, bathymetry is used to motivate a simple dynamical framework for flow over trenches. if the trench sides are sufficiently steep and the trench is sufficiently removed from the equator to ensure a region of closed geostrophic contours, then any upwelling over that region will drive a strong deep cyclonic recirculation in the weakly-stratified abyss through vortex stretching. The magnitude of this recirculation is limited by bottom drag. Ageostrophic flow in a bottom Ekman layer into the trench balances the water upwelled over the trench. The cyclonic recirculation is much stronger than the upwelling-driven flow predicted across blocked geostrophic contours by the Linear planetary geostrophic balance. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Johnson, GC (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne,Bldg 3, Seattle, WA 98115 USA. RI Johnson, Gregory/I-6559-2012 OI Johnson, Gregory/0000-0002-8023-4020 NR 34 TC 24 Z9 24 U1 0 U2 9 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 1998 VL 56 IS 2 BP 329 EP 347 DI 10.1357/002224098321822339 PG 19 WC Oceanography SC Oceanography GA ZN407 UT WOS:000073642800002 ER PT J AU Drews, AR Cline, JP Vanderah, TA Salazar, KV AF Drews, AR Cline, JP Vanderah, TA Salazar, KV TI High-temperature x-ray diffraction studies of a precursor mixture for Pb-substituted Bi-2223 superconducting mires SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CRYSTAL-STRUCTURE AB High-temperature x-ray diffraction measurements of a (Bi, Pb)-2223 precursor mixture used to produce high-J(c) superconducting tapes were conducted on silver and ZrO2 substrates. The precursor mixture consisted primarily of 2212, Ca2PbO4, and CuO. Phase evolution was markedly sensitive to oxygen partial pressure: In 10% O-2 growth of the 2223 phase on silver was rapid, proceeded at the expense of the 2212 phase, and was preceded by the disappearance of the Ca2PbO4 phase. When slowly heated on a silver substrate in 7.5% O-2 the 2212 phase melted near 800 degrees C and subsequently recrystallized near 820 degrees C in a highly textured form, but with no detectable 2223 formation. Under similar conditions on a ZrO2 substrate, the mixture exhibited no marked changes in the XRD patterns up to 850 degrees C. The dramatic reactivity on silver was also highly dependent on heating rate; rapid heating in 7.5% O-2 to 825 degrees C did not result in melting of the 2212 phase or appearance of the 2223 phase. In experiments leading to formation of 2223, the c-lattice parameter of the 2212 phase contracted just prior to the onset of formation of 2223. This result is consistent with the formation of an intermediate Pb-doped phase of 2212. A transient amorphous phase appeared briefly at the onset of formation of 2223. No evidence for intergrowth conversion of 2212 to 2223 was observed. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Drews, AR (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 24 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 1998 VL 13 IS 3 BP 574 EP 582 DI 10.1557/JMR.1998.0073 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA ZJ207 UT WOS:000073190200007 ER PT J AU Gonzalez, EJ Blendell, JE Cline, JP Ritter, JJ Maruthamuthu, P Nelson, EH Horn, SB AF Gonzalez, EJ Blendell, JE Cline, JP Ritter, JJ Maruthamuthu, P Nelson, EH Horn, SB TI Texture development in Bi2Te3 during hot forging SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ORIENTATION AB The development of crystallographic texture in hot-forged polycrystalline Bi2Te3 samples was studied. Texture was evaluated with the use of the March-Dollase model in conjunction with a Rietveld analysis of x-ray diffraction data. It was determined that during forging a strong (0001) texture develops along the loading axis. The magnitude of the (0001) texture increases systematically with the amount of height reduction during hot-forging. The correlation between the observed deformation and the March-Dollase texture model suggests that grain rotation is the primary mechanism for texture development in Bi2Te3. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Univ Madras, Dept Energy, Madras 600025, Tamil Nadu, India. USA, Res Lab, Sensor & Electron Devices Directorate, Ft Belvoir, VA 22060 USA. USA, Night Vis & Elect Sensors Directorate, Infrared Technol Branch, Ft Belvoir, VA 22060 USA. RP Gonzalez, EJ (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. NR 13 TC 7 Z9 7 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 MAR PY 1998 VL 13 IS 3 BP 766 EP 773 DI 10.1557/JMR.1998.0097 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA ZJ207 UT WOS:000073190200031 ER PT J AU Suenram, RD Lovas, FJ Quade, CR Su, CF AF Suenram, RD Lovas, FJ Quade, CR Su, CF TI Observation of tunneling states within the two conformations of hydroxyl gauche, methyl asymmetric CH2DCH2OH SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID ZERO-POINT ENERGY; INTERNAL-ROTATION; ETHYL-ALCOHOL; MICROWAVE; DEPENDENCE; MOLECULES; SPECTRUM AB Fourier transform microwave (FTMW) spectroscopy has been used to observe and resolve the 60-kHz tunneling splitting between the symmetric and antisymmetric substates of conformations I and II for hydroxyl gauche, methyl asymmetric CH2DCH2OH. Conformation I has the hydroxyl H and methyl D on the same side of the molecular plane whereas conformation II has them on the opposite sides. The determination of the small energy difference between these two conformers leads to an improved value of V-s1s2, (the potential energy coefficient that localizes the molecule into conformations I and II) of 4.8(5) cm(-1). Further, the relative intensities of the spectra show that conformation II is lower in energy than conformation I. Analysis of the quadrupole splittings of the a-type 1(01)-0(00) transitions determines values for eQq(aa) that range from -87 to -98 kHz for both hydroxyl conformations with the methyl group asymmetric and +84 to +102 kHz for both hydroxyl conformations with the methyl group symmetric. (C) 1998 Academic Press. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Texas Tech Univ, Dept Phys, Lubbock, TX 79409 USA. Mississippi State Univ, Dept Phys & Astron, Mississippi State, MS 39762 USA. RP Suenram, RD (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 14 TC 5 Z9 5 U1 2 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAR PY 1998 VL 188 IS 1 BP 9 EP 13 DI 10.1006/jmsp.1997.7505 PG 5 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA YZ914 UT WOS:000072307200002 ER PT J AU Vasconcellos, ECC Zerbetto, SC Zink, LR Evenson, KM Lees, RM Xu, LH AF Vasconcellos, ECC Zerbetto, SC Zink, LR Evenson, KM Lees, RM Xu, LH TI C-13 methanol far-infrared laser: Newly discovered lines, predictions, and assignments SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article AB We report 25 new laser lines from (CH3OH)-C-13 methanol when pumped by a cw CO2 laser. The majority of the lines are pumped by the 10R (regular) and 10SR (sequence) bands of the CO2 laser. Two are pumped by the 9HP(20) hot-band CO2 line. We measured 22 laser frequencies in this molecule, 19 from new lines and three from previously reported lines. We also remeasured and corrected the frequency of the 9P(44) pumped line as 3 378 404.87 MHz (88.738 mu m). We assigned two lines-10SR(17), 77.5758 cm(-1) and 10R(50), 119.3020 cm(-1)-and predicted other potential far-infrared laser lines with these two pumps. (C) 1998 Academic Press. C1 Univ Estadual Campinas, Inst Fis Gleb Wataghin, Dept Eletron Quant, BR-13083970 Campinas, SP, Brazil. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. Univ New Brunswick, Dept Phys, Fredericton, NB E3B 5A3, Canada. Univ New Brunswick, Dept Phys Sci, St John, NB E2L 4L5, Canada. RP Vasconcellos, ECC (reprint author), Univ Estadual Campinas, Inst Fis Gleb Wataghin, Dept Eletron Quant, BR-13083970 Campinas, SP, Brazil. RI Xu, Li-Hong/J-5095-2015; Inst. of Physics, Gleb Wataghin/A-9780-2017 NR 6 TC 7 Z9 7 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAR PY 1998 VL 188 IS 1 BP 102 EP 105 DI 10.1006/jmsp.1997.7496 PG 4 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA YZ914 UT WOS:000072307200012 ER PT J AU Lafferty, WJ Flaud, JM Guelachvili, G AF Lafferty, WJ Flaud, JM Guelachvili, G TI Analysis of the 2 nu(1) band system of SO2 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID LINE POSITIONS; (SO2)-S-32-O-16; INTENSITIES C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Univ Paris Sud, CNRS, Photophys Mol Lab, F-91405 Orsay, France. Univ Paris Sud, CNRS, Lab Phys Mol & Applicat, F-91405 Orsay, France. RP Lafferty, WJ (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 7 TC 18 Z9 20 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAR PY 1998 VL 188 IS 1 BP 106 EP 107 DI 10.1006/jmsp.1997.7493 PG 2 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA YZ914 UT WOS:000072307200013 ER PT J AU Zimmerman, BE Coursey, BM Cessna, JT AF Zimmerman, BE Coursey, BM Cessna, JT TI Correct use of dose calibrator values SO JOURNAL OF NUCLEAR MEDICINE LA English DT Letter C1 NIST, Phys Lab, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. RP Zimmerman, BE (reprint author), NIST, Phys Lab, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAR PY 1998 VL 39 IS 3 BP 575 EP 575 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZA974 UT WOS:000072421600043 PM 9529313 ER PT J AU Jacox, ME AF Jacox, ME TI Vibrational and electronic energy levels of polyatomic transient molecules. Supplement A SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Article DE electronic energy levels; emission spectra; experimental data; free radicals; gas phase; high-temperature molecules; infrared spectra; laser-excited fluorescence; matrix isolation; molecular ions; photoelectron spectroscopy; polyatomic molecules; radiative lifetimes; Raman spectra; rotational constants; transient molecules; ultraviolet absorption; vibrational energy levels ID CHARGE-TRANSFER STATES; INERT SOLID MATRICES; DIATOMIC-MOLECULES; GAS-PHASE; PHOTOGENERATION; IONS AB A summary is presented of recently published, critically evaluated experimental vibrational and electronic energy level data for neutral and ionic transient molecules and high temperature species possessing from three to sixteen atoms. Although the emphasis is on species with lifetimes too short for study using conventional sampling techniques, there has been selective extension of the compilation to include data for isolated molecules of inorganic species such as the heavy-metal oxides, which are important in a wide variety of industrial chemical systems. Radiative lifetimes and the principal rotational constants are included. Observations in the gas phase, in molecular beams, and in rare-gas and diatomic molecule matrices are evaluated. The types of measurement surveyed include conventional and laser-based absorption and emission techniques, laser absorption with mass analysis, and photoelectron spectroscopy. Not counting isotopic species, 904 molecules are surveyed, and 2696 distinct references are given. (C) 1998 American Institute of Physics and American Chemical Society. [S0047-2689(98)00102-0]. C1 NIST, Technol Adm, US Dept Commerce, Gaithersburg, MD 20899 USA. RP Jacox, ME (reprint author), NIST, Technol Adm, US Dept Commerce, Gaithersburg, MD 20899 USA. NR 21 TC 92 Z9 93 U1 0 U2 24 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD MAR-APR PY 1998 VL 27 IS 2 BP 115 EP 393 PG 279 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA ZH966 UT WOS:000073166200001 ER PT J AU Kushner, PJ McIntyre, ME Shepherd, TG AF Kushner, PJ McIntyre, ME Shepherd, TG TI Coupled Kelvin-wave and mirage-wave instabilities in semigeostrophic dynamics SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SEMI-GEOSTROPHIC DYNAMICS; ACTIVITY CONSERVATION-LAWS; STABILITY THEOREMS; FORMULATION; MODELS AB A weak instability mode, associated with phase-locked counterpropagating coastal Kelvin waves in horizontal anticyclonic shear, is found in the semigeostrophic (SG) equations for stratified how in a channel. This SG instability mode approximates a similar mode found in the Euler equations in the limit in which particle-trajectory slopes are much smaller than f/N, where f is the Coriolis frequency and N > f the buoyancy frequency. Though weak under normal parameter conditions, this instability mode is of theoretical interest because its existence accounts for the failure of an Arnol d-type stability theorem for the SG equations. In the opposite limit, in which the particle motion is purely vertical, the Euler equations allow only buoyancy oscillations with no horizontal coupling. The SG equations, on the other hand, allow a physically spurious coastal "mirage wave," so called because its velocity field vanishes despite a nonvanishing disturbance pressure field. Counterpropagating pairs of these waves can phase-lock to form a spurious "mirage-wave instability." Closer examination shows that the mirage wave arises from failure of the SG approximations to be self-consistent for trajectory slopes greater than or similar to f/N. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. Univ Cambridge, Dept Appl Math & Theoret Phys, Ctr Atmospher Sci, Cambridge CB3 9EW, England. Univ Toronto, Dept Phys, Toronto, ON, Canada. RP Kushner, PJ (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, Forrestal Campus, Princeton, NJ 08544 USA. RI Kushner, Paul/H-6716-2016 OI Kushner, Paul/0000-0002-6404-4518 NR 14 TC 10 Z9 10 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD MAR PY 1998 VL 28 IS 3 BP 513 EP 518 DI 10.1175/1520-0485(1998)028<0513:CKWAMW>2.0.CO;2 PG 6 WC Oceanography SC Oceanography GA ZA958 UT WOS:000072419700007 ER PT J AU Kirkley, J Squires, D Strand, IE AF Kirkley, J Squires, D Strand, IE TI Characterizing managerial skill and technical efficiency in a fishery SO JOURNAL OF PRODUCTIVITY ANALYSIS LA English DT Article DE technical efficiency; managerial skill; and fisheries ID FRONTIER PRODUCTION FUNCTION; SPECIFICATION; TESTS AB Researchers have long recognized that entrepreneurial or managerial skill is a major determinant of productivity or reason why production among firms varies. Yet, except for a few studies, differences in productivity and output levels are usually attributed to plant configuration or scale. More important, there appears to have been few attempts to relate technical efficiency to managerial skill. Utilizing a stochastic production frontier: we examine the relationship between technical efficiency and characteristics of skill such as experience and education in a fishery. Although we can not determine threshold or essential levels of experience and education, substitution possibilities are found to exist between years of experience and education levels. Additional analysis of efficiency for two captains of the same background and experience reveals that additional characteristics need to be considered in the examination of skipper skill or the "good-captain" hypothesis. C1 Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. SW Fisheries Sci Ctr, Natl Marine Fisheries Serv, La Jolla, CA 92038 USA. Univ Maryland, Dept Agr & Resource Econ, College Pk, MD 20742 USA. RP Kirkley, J (reprint author), Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. EM jkirkley@vims.edu; dsquires@its.ucsd.edu NR 39 TC 77 Z9 78 U1 2 U2 9 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0895-562X J9 J PROD ANAL JI J. Prod. Anal. PD MAR PY 1998 VL 9 IS 2 BP 145 EP 160 DI 10.1023/A:1018308617630 PG 16 WC Business; Economics; Social Sciences, Mathematical Methods SC Business & Economics; Mathematical Methods In Social Sciences GA ZF192 UT WOS:000072872900004 ER PT J AU Ma, Q Tipping, RH Birnbaum, G Boulet, C AF Ma, Q Tipping, RH Birnbaum, G Boulet, C TI Sum rules and the symmetry of the memory function in spectral line shape theories SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT 4th Conference on Atmospheric Spectroscopy Applications CY SEP 04-06, 1996 CL REIMS, FRANCE SP Int Radiat Commiss ID COLLISIONAL REDISTRIBUTION; DENSITY-MATRIX; RADIATION; MOTION AB Starting from the well-known expression between the absorption coefficient and the spectral density F(omega), the Fourier transform of the dipole correlation function, we use a projection operator to average out the degrees of freedom of the bath variables. As a result, F(omega) can be written in terms of a memory function and effects due to initial correlations, all of which are confined to the line space of the absorber molecule. The initial correlations influence the form of the spectral density and are necessary in order to satisfy the principle of detailed balance. There is a relationship between the existence of sum rules and the symmetry of the memory function matrix and the latter depends on the projection operator introduced. In the present case, the matrix of the memory function is asymmetric and only one-sided sum rules are valid. The above conclusions remain true within the binary collision approximation that is applicable to low density gases. Finally, we discuss previously published two-sided sum rules that have been derived using a different projection operator and consequently a different memory function. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Columbia Univ, Dept Appl Phys, New York, NY 10025 USA. NASA, Goddard Space Flight Ctr, Inst Space Studies, New York, NY 10025 USA. Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Paris Sud, CNRS UPR 136, Lab Phys Mol & Applicat, F-91405 Orsay, France. RP Ma, Q (reprint author), Columbia Univ, Dept Appl Phys, 2880 Broadway, New York, NY 10025 USA. NR 16 TC 13 Z9 13 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD MAR-MAY PY 1998 VL 59 IS 3-5 BP 259 EP 271 DI 10.1016/S0022-4073(97)00115-5 PG 13 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR495 UT WOS:000071501000012 ER PT J AU Estler, WT AF Estler, WT TI Uncertainty analysis for angle calibrations using circle closure SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE angle metrology; autocollimators, calibration; closure; dimensional metrology; indexing tables; measurement uncertainty; optical polygons; self-calibration AB We analyze two types of full-circle angle calibrations: a simple closure in which a single set of unknown angular segments is sequentially compared with an unknown reference angle, and a dual closure in which two divided circles are simultaneously calibrated by intercomparison. In each case, the constraint of circle closure provides auxiliary information that (1) enables a complete calibration process without reference to separately calibrated reference artifacts, and (2) serves to reduce measurement uncertainty. We derive closed-form expressions for the combined standard uncertainties of angle calibrations, following guidelines published by the International Organization for Standardization (ISO) and NIST. The analysis includes methods for the quantitative evaluation of the standard uncertainty of small angle measurement using electronic autocollimators, including the effects of calibration uncertainty and air turbulence. C1 Natl Inst Stand & Technol, Mfg Engn Lab, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Estler, WT (reprint author), Natl Inst Stand & Technol, Mfg Engn Lab, Div Precis Engn, Gaithersburg, MD 20899 USA. NR 12 TC 32 Z9 33 U1 0 U2 6 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1998 VL 103 IS 2 BP 141 EP 151 DI 10.6028/jres.103.008 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZT525 UT WOS:000074096600001 PM 28009359 ER PT J AU Eppeldauer, G AF Eppeldauer, G TI Chopped radiation measurements with large area Si photodiodes SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE bode plot; chopped light; detector, frequency dependence; gain; measurement; optical radiation; photocurrent; photodiode; radiometer; responsivity; silicon AB Frequency dependent response characteristics of photocurrent meters using large area, radiometric quality Si photodiodes have been analyzed. The current responsivity, the voltage noise and drift amplification, and the gain and bandwidth of the photocurrent-measuring analog control loop were calculated. The photodiodes were selected for high shunt resistance. The effect of the photodiode junction capacitance on the response characteristics was also analyzed. As a result of photocurrent gain dependent frequency compensations, the noise boosting effect was minimized at the output of the current meter. The loop gain and bandwidth were maximized. High-accuracy photocurrent measurements can be achieved using the described procedures for both de and modulated optical radiation. C1 Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Eppeldauer, G (reprint author), Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 15 TC 9 Z9 9 U1 1 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1998 VL 103 IS 2 BP 153 EP 162 DI 10.6028/jres.103.009 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZT525 UT WOS:000074096600002 PM 28009366 ER PT J AU Jeffery, A Shields, JQ Lee, LH AF Jeffery, A Shields, JQ Lee, LH TI An easy-to-use combination four-terminal-pair/two-terminal-pair AC transformer bridge SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ac bridge; four-terminal-pair bridge; four-terminal-pair measurements; precision impedance measurements; two-terminal-pair bridge AB A new four-terminal-pair bridge, capable of achieving a relative standard uncertainty of 1x10(-9), was constructed at the National Institute of Standards and Technology by converting a two-terminal-pair bridge. The conversion requires only the addition of components which are easily removed if two-terminal-pair measurements are to be made. The design and testing of this bridge is described. The new four-terminal-pair bridge requires fewer auxiliary balances than the present four-terminal-pair bridge employed at NIST, which makes it much easier to use. This new design can be used to compare capacitance, resistance, and inductance standards. C1 Natl Inst Stand & Technol, Elect & Elect Engn Lab, Div Elect, Gaithersburg, MD 20899 USA. RP Jeffery, A (reprint author), Natl Inst Stand & Technol, Elect & Elect Engn Lab, Div Elect, Gaithersburg, MD 20899 USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1998 VL 103 IS 2 BP 163 EP 166 DI 10.6028/jres.103.010 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZT525 UT WOS:000074096600003 PM 28009361 ER PT J AU Moldover, MR AF Moldover, MR TI Can a pressure standard be based on capacitance measurements? SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ab initio calculations; cross capacitor; dielectric constant; helium; polarizability; pressure standard; toroidal cross capacitor; molar polarizability ID VIRIAL-COEFFICIENTS; HELIUM; POLARIZABILITY; HE-4 AB We consider the feasibility of basing a pressure standard on measurements of the dielectric constant epsilon and the thermodynamic temperature T of helium near 0 degrees C. The pressure p of the helium would be calculated from fundamental constants, quantum mechanics, and statistical mechanics. At present, the relative standard uncertainty of the pressure u(r)(p) would exceed 20 x 10(-6), the relative uncertainty of the value of the molar polarizability of helium A(epsilon) calculated ab initio. If the relativistic corrections to A(epsilon) were calculated as accurately as the classical value is now known, a capacitance-based pressure standard might attain u(r)(p)< 6 x 10(-6) for pressures near 1 MPa, a result of considerable interest for pressure metrology. One obtains p by eliminating the density from the virial expansions for p and epsilon - 1. If epsilon - 1 were measured with a very stable, 0.5 pF toroidal cross capacitor, the small capacitance and the small values of epsilon - 1 would require state-of-the-art capacitance measurements to achieve a useful pressure standard. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Fluid Sci Grp, Gaithersburg, MD 20899 USA. RP Moldover, MR (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Fluid Sci Grp, Gaithersburg, MD 20899 USA. RI Moldover, Michael/E-6384-2013 NR 30 TC 39 Z9 39 U1 2 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1998 VL 103 IS 2 BP 167 EP 175 DI 10.6028/jres.103.011 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZT525 UT WOS:000074096600004 PM 28009367 ER PT J AU Lee, KC AF Lee, KC TI Degradation of GaAs/AlGaAs quantized Hall resistors with alloyed AuGe/Ni contacts SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE alloyed contacts; contact degradation; GaAs; gold-germanium-nickel; ohmic contacts; passivation; quantized Hall resistor; quantum Hall effect; 2-dimensional electron gas ID ELECTRON-MOBILITY TRANSISTORS; OHMIC CONTACTS; GAAS; RESISTANCE; TEMPERATURE; OXIDATION; STABILITY; STANDARD; DEVICES AB Careful testing over a period of 6 years of a number of GaAs/AlGaAs quantized Hall resistors (QHR) made with alloyed AuGe/Ni contacts, both with and without passivating silicon nitride coatings, has resulted in the identification of important mechanisms responsible for degradation in the performance of the devices as resistance standards: Covering the contacts with a film, such as a low-temperature silicon nitride, that is impervious to humidity and other contaminants in the atmosphere prevents the contacts from degrading. The devices coated with silicon nitride used in this study, however, showed the effects of a conducting path in parallel with the 2-dimensional electron gas (2-DEG) at temperatures above 1.1 K which interferes with their use as resistance standards. Several possible causes of this parallel conduction are evaluated. On the basis of this work, two methods are proposed for protecting QHR devices with alloyed AuGe/Ni contacts from degradation: the heterostructure can be left unpassivated, but the alloyed contacts can be completely covered with a very thick (> 3 mu m) coating of gold; or the GaAs cap layer can be carefully etched away after alloying the contacts and prior to depositing a passivating silicon nitride coating over the entire sample. Of the two, the latter is more challenging to effect, but preferable because both the contacts and the heterostructure are protected from corrosion and oxidation. C1 Natl Inst Stand & Technol, Elect & Elect Engn Lab, Div Elect, Gaithersburg, MD 20899 USA. RP Lee, KC (reprint author), Natl Inst Stand & Technol, Elect & Elect Engn Lab, Div Elect, Gaithersburg, MD 20899 USA. NR 32 TC 5 Z9 5 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1998 VL 103 IS 2 BP 177 EP 200 DI 10.6028/jres.103.012 PG 24 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZT525 UT WOS:000074096600005 PM 28009368 ER PT J AU Kotochigova, S Tupitsyn, I AF Kotochigova, S Tupitsyn, I TI Accurate ab initio calculation of molecular constants SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE AgH+ molecule; diatomic molecule; dissociation energy; equilibrium bond distance; molecular constants; OH molecule; valence-bond method; vibrational and rotational constants AB Molecular constants have been computed for the ground states (2) Pi of (OH)-O-17 and (1) Sigma of (AgH+)-Ag-107. The valence-bond method and advanced computational technique were used to perform all-electron ab initio calculation of molecular electronic structures. The basic idea behind the model is to introduce the molecular wave functions in terms of Hartree-Fock many-electron atomic determinants. Full configuration interaction (CI) with nonorthogonal basis leads to the accurate calculation of molecular constants such as dissociation energy, equilibrium bond distance, vibrational and rotational constants with an agreement to the experimental data within a few percent. C1 St Petersburg State Univ, Dept Phys, St Petersburg 198904, Russia. RP Kotochigova, S (reprint author), Natl Inst Stand & Technol, Phys Lab, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Tupitsyn, Ilya/J-6611-2013 OI Tupitsyn, Ilya/0000-0001-9237-5667 NR 10 TC 2 Z9 2 U1 1 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1998 VL 103 IS 2 BP 201 EP 204 DI 10.6028/jres.103.013 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZT525 UT WOS:000074096600006 PM 28009365 ER PT J AU Tupitsyn, I Kotochigova, S AF Tupitsyn, I Kotochigova, S TI Hyperfine structure constants for diatomic molecules SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE AgH+ molecule; diatomic molecules; Fermi contact term; hyperfine structure; OH molecule; valence-bond method ID ATOMS AB The multiconfiguration valence-bond method (VB) is applied to diatomic molecules using the Hartree-Fock (HF) atomic basis set. The hyperfine constant, Fermi contact term, is computed as a function of the interatomic separation for the X-2 Pi ground state of (OH)-O-17 and X-1 Sigma ground state of (AgH+)-Ag-107 molecules. This study leads to a number of conclusions about the influence of correlation and polarization effects on the hyperfine structure of hydrogenic molecules. The calculated values of the Fermi contact term are found to agree within 1 % of the experimental values wherever available. C1 St Petersburg State Univ, Dept Phys, St Petersburg 198904, Russia. Natl Inst Stand & Technol, Phys Lab, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Tupitsyn, I (reprint author), St Petersburg State Univ, Dept Phys, St Petersburg 198904, Russia. RI Tupitsyn, Ilya/J-6611-2013 OI Tupitsyn, Ilya/0000-0001-9237-5667 NR 7 TC 4 Z9 4 U1 0 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1998 VL 103 IS 2 BP 205 EP 207 DI 10.6028/jres.103.014 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZT525 UT WOS:000074096600007 PM 28009357 ER PT J AU de Astarloa, JMD Munroe, TA AF de Astarloa, JMD Munroe, TA TI Systematics, distribution and ecology of commercially important paralichthyid flounders occurring in Argentinean-Uruguayan waters (Paralichthys, Paralichthyidae): an overview SO JOURNAL OF SEA RESEARCH LA English DT Article; Proceedings Paper CT 3rd International Symposium on Flatfish CY NOV 02-08, 1996 CL NETHERLANDS INST SEA RES, TEXEL, NETHERLANDS HO NETHERLANDS INST SEA RES DE Paralichthys spp.; Southwestern Atlantic; distribution; ecology; systematics ID ABUNDANCE; ATLANTIC AB Species of Paralichthys Girard are the most important flatfishes to commercial fisheries in nearshore waters of Argentina and Uruguay. Recent commercial catches increased from 3000 tonnes (t) in 1984 to 11000 t in 1995, representing more than $65 million in export income for 1995. Although their commercial importance has long been recognized, paralichthyid flounders in this region are not well studied, either from a systematic or an ecological viewpoint. Six nominal species have been reported from Argentinean and Uruguayan waters: Paralichthys bicyclophorus, P. brasiliensis, P. isosceles, P. orbignyanus, P. patagonicus and P. simulans. However, species descriptions are often vague and incomplete, and reported distributions are dubious. Variations in scale morphology, meristic and morphometric characters were used to differentiate among the Paralichthys species co-occurring in this area. Of six species previously reported from this region, only three, P. isosceles, P. orbignyanus and P. patagonicus, are valid. P. bicyclophorus is regarded as a junior synonym of P. patagonicus; P. simulans is a junior synonym of P. orbignyanus; while P. brasiliensis, although reported from coastal waters of Argentina and Uruguay for many years, does not occur there. Paralichthys spp. were collected on the continental shelf and in estuaries in the south Atlantic between 34-55 degrees S. P. orbignyanus and P. patagonicus inhabit marine and estuarine locations and extend as far south as 43 degrees S. The former is a shallow-water, euryhaline species occurring to about 20 m. In contrast, P. patagonicus has higher densities between 36-40 degrees S at 70-100 m depth. P. isosceles occurs mainly on the inner continental shelf between 43-45 degrees S at 70-100 m depth, and reaches its southern Limit at about 47 degrees S. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Mar del Plata, Fac Ciencias Exactas & Nat, Dept Ciencias Marinas, RA-7600 Mar Del Plata, Argentina. Natl Museum Nat Hist, Natl Marine Fisheries Serv, Natl Systemat Lab, Washington, DC 20560 USA. RP de Astarloa, JMD (reprint author), Univ Mar del Plata, Fac Ciencias Exactas & Nat, Dept Ciencias Marinas, Funes 3350, RA-7600 Mar Del Plata, Argentina. NR 39 TC 20 Z9 21 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1385-1101 J9 J SEA RES JI J. Sea Res. PD MAR PY 1998 VL 39 IS 1-2 BP 1 EP 9 DI 10.1016/S1385-1101(97)00010-5 PG 9 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA ZE466 UT WOS:000072795700001 ER PT J AU Johnson, LL Landahl, JT Kubin, LA Horness, BH Myers, MS Collier, TK Stein, JE AF Johnson, LL Landahl, JT Kubin, LA Horness, BH Myers, MS Collier, TK Stein, JE TI Assessing the effects of anthropogenic stressors on Puget Sound flatfish populations SO JOURNAL OF SEA RESEARCH LA English DT Article; Proceedings Paper CT 3rd International Symposium on Flatfish CY NOV 02-08, 1996 CL NETHERLANDS INST SEA RES, TEXEL, NETHERLANDS HO NETHERLANDS INST SEA RES DE population growth rate; mortality; fecundity; contaminant; English sole; Leslie matrix model ID SOLE PAROPHRYS-VETULUS; FLOUNDER PLEURONECTES-AMERICANUS; DAB LIMANDA-LIMANDA; ENGLISH SOLE; WINTER FLOUNDER; HEPATIC-LESIONS; REPRODUCTIVE SUCCESS; CHEMICAL CONTAMINANTS; BENTHIC FISH; AROMATIC-HYDROCARBONS AB Puget Sound is an estuary in the northwestern United States which serves as the habitat for a number of recreationally and commercially important species of flatfish. Over the past 100 years, there has been substantial urban and industrial development within this region, resulting in heavy inputs of chemical contaminants at selected sites, as well as significant loss or alteration of marine habitat. Studies show that feral flatfish in Puget Sound are experiencing a range of biological effects due to chemical contaminant exposure, including reproductive dysfunction, altered immune competence, and development of toxicopathic diseases, and there is some evidence of reduced survival in fish from urban areas of Puget Sound from increased infectious and toxicopathic disease. Puget Sound sole are also subject to other anthropogenic stressors, such as fishing pressure or alteration of nearshore nursery habitats. The cumulative impact of these stressors on flatfish abundance in Puget Sound, however, is poorly understood. In a series of field and laboratory studies, we determined vital rates and other life history parameters in English sole (Pleuronectes vetulus) subpopulations from urban and non-urban sites in Puget Sound, and are using this information to estimate potential population level impacts of anthropogenic stressors, with age and stage-based Leslie-matrix models. Initial results suggest that declines in the fecundity component of the model, as observed in field studies of fish from contaminated sites, could reduce the size of sub-populations in these areas if the loss of recruits is aot offset by density-dependent changes in recruitment, immigration, or other compensating mechanisms. Studies on flatfish species from a variety of sites in Europe and North America suggest that contaminant-related disease and reproductive impairment are widespread in this group of fish, although substantial differences in sensitivity have been observed, even among closely related species. Comparative studies with a variety of Pleuronectid species will enable us to better evaluate the risk posed by anthropogenic stressors to flatfish, and contribute to improved assessment and management of this important fisheries resource. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Johnson, LL (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. EM ljohnson@sci.nwfsc.noaa.gov NR 82 TC 46 Z9 48 U1 3 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1385-1101 J9 J SEA RES JI J. Sea Res. PD MAR PY 1998 VL 39 IS 1-2 BP 125 EP 137 DI 10.1016/S1385-1101(97)00057-9 PG 13 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA ZE466 UT WOS:000072795700010 ER PT J AU Biegalski, SR Landsberger, S Hoff, RM AF Biegalski, SR Landsberger, S Hoff, RM TI Source-receptor modeling using trace metals in aerosols collected at three rural Canadian Great Lakes sampling stations SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID NEUTRON-ACTIVATION ANALYSIS; LIMIT; AIR; CONTAMINANTS; DEPOSITION; POLLUTION; ELEMENTS; BROMINE; LESS AB High-volume air samplers were used to collect aerosol samples on Whatman 41 air filters at the Canadian air sampling stations Burnt Island, Egbert, and Point Petre. The samples were analyzed for trace elements by neutron activation analysis. Air concentrations of over 30 trace elements were determined. Factor analysis; elemental ratios, and enrichment factor analysis were used to determine source-receptor relationships at the three different sites. Factor analysis exhibited trends that indicate oil and coal combustion, road salt, mining, incineration, and smelting as anthropogenic sources to aerosols of the rural Great Lakes. Elemental ratios showed that the Na to Cl ratio in the Great Lakes aerosol is similar to that found in sea water. Enrichment factor analysis revealed elements with non-crustal sources including the elements Ag, As, Br, Cl, Cu, I, In, Sb, Se, Sn, W, and Zn. C1 Univ Illinois, Dept Nucl Engn, Urbana, IL 61801 USA. Ctr Atmos Res Experiments, Atmospher Env Serv, Ontario, ON, Canada. RP Biegalski, SR (reprint author), Natl Inst Standards & Technol, Chem B364, Gaithersburg, MD 20876 USA. RI Biegalski, Steven/A-7765-2010; Hoff, Raymond/C-6747-2012 NR 45 TC 32 Z9 33 U1 3 U2 3 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD MAR PY 1998 VL 48 IS 3 BP 227 EP 237 PG 11 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZF768 UT WOS:000072931200007 ER PT J AU Lee, KS Wuttiphan, S Hu, XZ Lee, SK Lawn, BR AF Lee, KS Wuttiphan, S Hu, XZ Lee, SK Lawn, BR TI Contact-induced transverse fractures in brittle layers on soft substrates: A study on silicon nitride bilayers SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID INDENTATION FRACTURE; CERAMIC COATINGS; CRACK DEFLECTION; DAMAGE; INTERFACES; DEFORMATION; MECHANICS; BEHAVIOR; DUCTILE; FILMS AB An analysis of transverse cracks induced in brittle coatings on soft substrates by spherical indenters is developed, The transverse cracks are essentially axisymmetric and geometrically conelike, with variant forms dependent on the location of initiation: outer cracks that initiate at the top surface outside the contact and propagate downward; inner cracks that initiate at the coating/substrate interface beneath the contact and propagate upward; intermediate cracks that initiate within the coating and propagate in both directions, Bilayers consisting of hard silicon nitride (coating) on a composite underlayer of silicon nitride with boron nitride platelets (substrate), with strong interfacial bonding to minimize delamination, are used as a model test system for Hertzian testing. Test variables investigated are contact load, coating/substrate elastic-plastic mismatch (controlled by substrate boron nitride content), and coating thickness, Initiation of the transverse coating cracks occurs at lower critical loads, and shifts from the surface to the interface, with increasing elastic-plastic mismatch and decreasing coating thickness, This shift is accompanied by increasing quasi-plasticity in the substrate, Once initiated, the cracks pop in and arrest within the coating, becoming highly stabilized and insensitive to further increases in contact load, or even to coating toughness, A finite element analysis of the stress fields in the loaded layer systems enables a direct correlation between the damage patterns and the stress distributions: between the transverse cracks and the tensile (and compressive) stresses; and between the subsurface yield zones and the shear stresses, Implications of these conclusions concerning the design of coating systems for damage tolerance are discussed. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Lee, KS (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Hu, Xiaozhi /H-4353-2011 NR 31 TC 64 Z9 66 U1 2 U2 7 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 1998 VL 81 IS 3 BP 571 EP 580 PG 10 WC Materials Science, Ceramics SC Materials Science GA ZC554 UT WOS:000072592300016 ER PT J AU Rukhin, AL Vangel, MG AF Rukhin, AL Vangel, MG TI Estimation of a common mean and weighted means statistics SO JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION LA English DT Article DE heteroscedasticity; interlaboratory study; Mandel-Paule algorithm; maximum likelihood estimator; unbalanced one-way analysis of variance model; variance components AB Measurements made by several laboratories may exhibit nonnegligible between-laboratory variability, as well as different within-laboratory variances. Also, the number of measurements made at each laboratory often differ. Questions of fundamental importance in the analysis of such data are how to form a best consensus mean, and what uncertainty to attach to this estimate. An estimation equation approach due to Mandel and Paule is often used at the National Institute of Standards and Technology (NIST), particularly when certifying standard reference materials. Primary goals of this article are to study the theoretical properties of this method, and to compare it with some alternative methods, in particular to the maximum Likelihood estimator (MLE). Toward this end, we show that the Mandel-Paule solution can be interpreted as a simplified version of the maximum likelihood method. A class of weighted means statistics is investigated for situations where the number of laboratories is large. This class includes a modified MLE and the Mandel-Paule procedure. Large-sample behavior of the distribution of these estimators is investigated. This study leads to a utilizable estimate of the variance of the Mandel-Paule statistic and to an approximate confidence interval for the common mean. It is shown that the Mandel-Paule estimator of the between-laboratory variance is inconsistent in this setting. The results of numerical comparison of mean squared errors of these estimators for a special distribution of within-laboratory variances are also reported. C1 Univ Maryland Baltimore Cty, Dept Math & Stat, Baltimore, MD 21250 USA. Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. RP Rukhin, AL (reprint author), Univ Maryland Baltimore Cty, Dept Math & Stat, Baltimore, MD 21250 USA. NR 15 TC 65 Z9 65 U1 0 U2 6 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0162-1459 J9 J AM STAT ASSOC JI J. Am. Stat. Assoc. PD MAR PY 1998 VL 93 IS 441 BP 303 EP 308 DI 10.2307/2669626 PG 6 WC Statistics & Probability SC Mathematics GA ZA356 UT WOS:000072355300030 ER PT J AU Slifka, AJ Filla, BJ Phelps, JM Bancke, G Berndt, CC AF Slifka, AJ Filla, BJ Phelps, JM Bancke, G Berndt, CC TI Thermal conductivity of a zirconia thermal barrier coating SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE thermal barrier coating; thermal conductivity; thermal resistance; zirconia AB The conductivity of a thermal-barrier coating composed of atmospheric plasma sprayed 8 mass percent yttria partially stabilized zirconia has been measured. This coating was sprayed on a substrate of 410 stainless steel. An absolute, steady-state measurement method was used to measure thermal conductivity from 400 to 800 K. The thermal conductivity of the coating is 0.62 W/(m.K). This measurement has shown to be temperature independent. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. SUNY Stony Brook, Thermal Spray Lab, Stony Brook, NY 11794 USA. NR 12 TC 26 Z9 28 U1 4 U2 9 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD MAR PY 1998 VL 7 IS 1 BP 43 EP 46 DI 10.1007/s11666-006-5001-y PG 4 WC Materials Science, Coatings & Films SC Materials Science GA ZB684 UT WOS:000072497200032 ER PT J AU Edwards, H Jorgensen, JF Dagata, J Strausser, Y Schneir, J AF Edwards, H Jorgensen, JF Dagata, J Strausser, Y Schneir, J TI Influence of data analysis and other factors on the short-term stability of vertical scanning-probe microscope calibration measurements SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID ATOMIC-FORCE MICROSCOPY; SAMPLE DISTANCE CONTROL; HEIGHT AB We report a study of a fundamental limit to the accuracy of vertical measurements made using scanning-probe microscopes (SPM): the short-term stability of a vertical calibration using a waffle-pattern artifact. To test the instrumental component of this stability, we acquired three data series, at different humidity levels. We compare the variations in waffle-pattern depth in these three data series with the differences in depth estimates using several different analysis methods. The three methods tested are: a histogram method, the scanning-probe image processor, and the polynomial step-function fit. To clarify the importance of the analysis method, a discussion of the different leveling, averaging, and depth-estimation aspects of the various methods is presented. To understand the true repeatability limit of SPM calibration, it is necessary to treat imaging artifacts such as tilt, nonlinearities, and image bow carefully. We find that, when such care is taken, the dependence of the average waffle-cell depth on algorithm is around 0.1%. This is less than the standard deviation of the step-height estimates of around 0.5%, which may be attributed to short-term instrumental variations in vertical SPM calibration This is a far better stability than the 5%-10% variations observed under long-term aging of the piezo scanner. However, the histogram algorithm, which does not correct image bow, gives an average waffle-cell depth estimate which is nearly 1% higher than the others, indicating that careful image analysis is necessary if the measurement accuracy is to be comparable to the short-term stability of the piezo scanner. (C) 1998 American Vacuum Society. [S0734-211X(98)01202-5]. C1 Texas Instruments Inc, Components & Mat Res Ctr, Dallas, TX 75265 USA. Danish Inst Fundamental Metrol, DK-2800 Lyngby, Denmark. NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. Digital Instruments, Santa Barbara, CA 93103 USA. Tencor, Metrol Div, Santa Clara, CA 95054 USA. RP Edwards, H (reprint author), Texas Instruments Inc, Components & Mat Res Ctr, Dallas, TX 75265 USA. EM edwards@ti.com NR 18 TC 11 Z9 13 U1 2 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAR-APR PY 1998 VL 16 IS 2 BP 633 EP 644 DI 10.1116/1.589933 PG 12 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA ZH976 UT WOS:000073167200029 ER PT J AU Hodell, DA Schelske, CL Fahnenstiel, GL Robbins, LL AF Hodell, DA Schelske, CL Fahnenstiel, GL Robbins, LL TI Biologically induced calcite and its isotopic composition in Lake Ontario SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID MUSSEL DREISSENA-POLYMORPHA; GREAT-LAKES; PHYTOPLANKTON GROWTH; BIOGENIC SILICA; SEDIMENT TRAP; EL-NINO; CARBON; EUTROPHICATION; PRECIPITATION; PRODUCTIVITY AB We studied water, sediment trap, and core samples from eastern Lake Ontario to reconstruct the factors controlling the biologically induced production and sedimentation of calcite during so-called whiting events. Calcite accumulation and its isotopic composition are controlled by a complex set of interrelated factors, including temperature, primary productivity, and the abundance of pico-cyanobacteria during the stratified period. Calcite precipitation is highly correlated to lake temperature, because physical and biological factors interact to produce conditions favorable for whitings during warm years when the lake stratifies early in the seasonal cycle. Carbonate stratigraphies in multiple cores from eastern Lake Ontario revealed similar patterns of historical variation in percent carbonate. An exponential rise in carbonate accumulation occurred in nine cores after 1930, culminating in peak values in the early 1980s. This rise was related to historic increases in primary productivity resulting from increased phosphorus loading to Lake Ontario. Superimposed upon this rise were four peaks (centered on 1940-1942, 1957-1961, 1971-1977, and 1983) that correlate with maxima in summer air-temperature anomalies from the Great Lakes region and with strong El Nino events. These peaks are also associated with maxima in delta(13)C values and minima in delta(18)O values of carbonate, lending support to our model that more calcite is precipitated with higher delta(13)C values during warm years when thermal stratification occurs early in the seasonal cycle. Beginning in the mid-1980s, calcite accumulation and its delta(13)C ratio began to decrease, suggesting a reduction in primary productivity in surface waters, probably related to lower phosphate concentrations in epilimnetic waters of Lake Ontario during the stratified period. Reduced summer P loading may be explained either by a lagged response to P abatement measures that began in the late 1970s or by decreased P loading from upstream Lake Erie beginning in the late 1980s as a result of the establishment of filter-feeding zebra mussels. C1 Univ Florida, Dept Geol, Gainesville, FL 32611 USA. Univ Florida, Dept Fisheries & Aquat Sci, Gainesville, FL 32606 USA. NOAA, Lake Michigan Field Stn, Great Lakes Environm Res Lab, Muskegon, MI 49441 USA. Univ S Florida, Dept Geol, Tampa, FL 33620 USA. RP Hodell, DA (reprint author), Univ Florida, Dept Geol, 1112 Turlington Hall, Gainesville, FL 32611 USA. NR 52 TC 118 Z9 127 U1 4 U2 25 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD MAR PY 1998 VL 43 IS 2 BP 187 EP 199 PG 13 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA ZR216 UT WOS:000073951900002 ER PT J AU Hare, JA Cowen, RK Zehr, JP Juanes, F Day, KH AF Hare, JA Cowen, RK Zehr, JP Juanes, F Day, KH TI A correction to: Biological and oceanographic insights from larval labrid (Pisces : Labridae) identification using mtDNA sequences SO MARINE BIOLOGY LA English DT Article ID MITOCHONDRIAL-DNA; EVOLUTION AB Previously published mtDNA cytochrome b sequences for Xyrichtys novacula (Linnaeus) and two morphologically distinct types of Xyrichtys larvae (Pisces: Labridae) included human cytochrome b sequence, presumably due to sample contamination and/or poor preservation of sample DNA. Those sequences had been used to identify the two types of Xyrichtys larvae as X. novacula, but owing to the contamination, the identifications are invalid. Fresh specimens were collected: X. martinicensis (Cuvier and Valenciennes), X. novacula, X. splendens (Castelnau), and Xyrichtys sp. larvae of each of the two morphotypes (dorsal-forward eye and ventral-forward eye). The cytochrome b fragment was amplified from each specimen using the polymerase chain reaction, Comparison of the sequences with human cytochrome b sequence confirmed that the new sequences were not contaminated. The interspecific differences in Xyrichtys sequences were less than previously reported, but still greater than observed in many fish genera. Distance and parsimony analyses indicated that X. novacula and X. martinicensis were more closely related to each other than to X. splendens. This conclusion differs from our previous conclusion that X. martinicensis and X. splendens were more closely related to each other than to X. novacula. Distance and parsimony analyses also demonstrated that both larval morphotypes were X. novacula and, thus, our previous conclusions regarding larval ecology and oceanographic transport remain unchanged. C1 SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. Univ Virginia, Dept Med, Charlottesville, VA 22908 USA. RP Hare, JA (reprint author), NOAA, Natl Marine Fisheries Serv, Beaufort Lab, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. RI Zehr, Jonathan/B-3513-2014 OI Zehr, Jonathan/0000-0002-5691-5408 NR 13 TC 2 Z9 2 U1 1 U2 2 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 1998 VL 130 IS 4 BP 589 EP 592 DI 10.1007/s002270050280 PG 4 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA ZG661 UT WOS:000073026500004 ER PT J AU Weinberg, JR AF Weinberg, JR TI Density-dependent growth in the Atlantic surfclam, Spisula solidissima, off the coast of the Delmarva Peninsula, USA SO MARINE BIOLOGY LA English DT Article ID SELF-THINNING RELATIONSHIPS; INTERSPECIFIC COMPETITION; SUSPENSION FEEDERS; SPACE LIMITATION; AGE; CLAM; SIZE; PREDATION; SHELL; FOOD AB Spisula solidissima (Dillwyn, 1817) is a large, suspension-feeding bivalve, whose range extends from Nova Scotia to South Carolina. This species is harvested commercially. Shell length and age data were collected for this species from 1980 to 1994 during surveys of population size and structure. These data were used to examine the relationship between the growth rate of S. solidissina and intraspecific density. The null hypothesis was that density (represented by number of individuals per tow) would have no effect on rate of growth. A negative relationship would support the alternative hypothesis, that intraspecific competition had taken place. This analysis focused on the surfclam population offshore from the Delmarva Peninsula, USA because: (1) a major recruitment event occurred in 1977, (2) clam fishermen had reported "stunted" surfclams in that area, (3) a wide range of local densities were available to examine, and (4) the existence of a closed area within the study area set up an interesting contrast with areas left open to harvesting. Maps of surfclam abundance across the Delmarva region demonstrate that areas of highest density have generally remained in the same location through time. The results suggested that intraspecific competition has been important in structuring this population. Based on data from 1980 to 1992, shell length was significantly reduced at high density, and a significant interaction between age and density was observed. Growth modeling indicated decreased asymptotic lengths and growth rates with increasing density. In nine out of ten pairwise randomization tests, fitted von Bertalanffy growth curves, representing different densities, were significantly different from each other. High densities of clams have persisted in the area that was closed to harvesting for 11 years (1980 to 1991). In 1994, length at age was significantly less in this closed area compared to that in the surrounding area. This effect was apparent in clams from 3 to 17 years of age, and most pronounced in the cohort that recruited to the Delmarva region in high numbers in 1977. Lower growth rates within the closed area have management implications for the optimal duration of closures. C1 Natl Marine Fisheries Serv, Populat Dynam Branch, Woods Hole, MA 02543 USA. RP Weinberg, JR (reprint author), Natl Marine Fisheries Serv, Populat Dynam Branch, Woods Hole, MA 02543 USA. NR 53 TC 29 Z9 30 U1 0 U2 5 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 1998 VL 130 IS 4 BP 621 EP 630 DI 10.1007/s002270050284 PG 10 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA ZG661 UT WOS:000073026500008 ER PT J AU Squires, D Campbell, H Cunningham, S Dewees, C Grafton, RQ Herrick, SF Kirkley, J Pascoe, S Salvanes, K Shallard, B Turris, B Vestergaard, N AF Squires, D Campbell, H Cunningham, S Dewees, C Grafton, RQ Herrick, SF Kirkley, J Pascoe, S Salvanes, K Shallard, B Turris, B Vestergaard, N TI Individual transferable quotas in multispecies fisheries SO MARINE POLICY LA English DT Review ID RENT CAPTURE; YELLOWFIN TUNA; NEW-ZEALAND; MANAGEMENT; INDUSTRY; PROPERTY; RIGHTS; UNCERTAINTY; ENFORCEMENT; INVESTMENT C1 Natl Marine Fisheries Serv, La Jolla, CA 92038 USA. Univ Queensland, St Lucia, Qld 4067, Australia. Univ Portsmouth, Portsmouth PO1 2UP, Hants, England. Univ Calif Davis, Davis, CA USA. Univ Ottawa, Ottawa, ON K1N 6N5, Canada. Virginia Inst Marine Sci, Gloucester, VA USA. Australian Bur Agr & Resource Econ, Canberra, ACT, Australia. Norwegian Sch Econ & Business Adm, N-5035 Bergen, Norway. Fisheries & Oceans Canada, Vancouver, BC, Canada. Danish Inst Fisheries Econ Res, Esbjerg, Denmark. RP Squires, D (reprint author), Natl Marine Fisheries Serv, POB 271, La Jolla, CA 92038 USA. RI Grafton, R. Quentin/A-5277-2008; Pascoe, Sean/D-9710-2011; OI Grafton, R. Quentin/0000-0002-0048-9083; Pascoe, Sean/0000-0001-6581-2649; Vestergaard, Niels/0000-0001-9270-2461 NR 116 TC 84 Z9 85 U1 2 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0308-597X J9 MAR POLICY JI Mar. Pol. PD MAR PY 1998 VL 22 IS 2 BP 135 EP 159 DI 10.1016/S0308-597X(97)00039-0 PG 25 WC Environmental Studies; International Relations SC Environmental Sciences & Ecology; International Relations GA YV812 UT WOS:000071865800005 ER PT J AU O'Connor, TP AF O'Connor, TP TI Comparative criteria: Land application of sewage sludge and ocean disposal of dredged material SO MARINE POLLUTION BULLETIN LA English DT Editorial Material AB That societal perceptions differ between use of the land and the ocean is exemplified by environmental regulations in the United States that allow much higher levels of chemical contamination in sewage sludge to be used on land than in dredged material to be dumped at sea. Criteria for sewage sludge acceptability for land application are bulk chemical concentrations. Criteria for acceptability of dredged material for disposal at sea focus upon biological testing for toxicity and bioaccumulation. The result is that sludge applied to land can have much higher levels of contamination than are commonly found even in sediments deemed unacceptable for disposal-at-sea. The inconsistencies between these criteria suggest re-evaluations of both. Published by Elsevier Science Ltd. C1 NOAA, Natl Status & Trends Program, Silver Spring, MD 20910 USA. RP NOAA, Natl Status & Trends Program, N-ORCA21,1305 East West Highway, Silver Spring, MD 20910 USA. EM tom.oconnor@noaa.gov NR 13 TC 11 Z9 12 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD MAR PY 1998 VL 36 IS 3 BP 181 EP 184 DI 10.1016/S0025-326X(97)00179-3 PG 4 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA ZU230 UT WOS:000074175300009 ER PT J AU Block, BA Dewar, H Williams, T Prince, ED Farwell, C Fudge, D AF Block, BA Dewar, H Williams, T Prince, ED Farwell, C Fudge, D TI Archival tagging of Atlantic bluefin tuna (Thunnus thynnus thynnus) SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article ID ACOUSTIC TELEMETRY; MARLIN; TEMPERATURE; SWORDFISH; DEPTH AB The size, power, and speed of tunas and other pelagic fishes (e.g. swordfish, martins, sailfish) have made it a challenge to study their biology. These species are most often composed of large populations with broad geographic ranges and individuals are capable of traversing ocean basins in weeks or months. Data on dispersal patterns are hard to obtain because of the limited resolution of analytical tools available for studying pelagic fish. What is currently needed are technologies that can augment conventional tagging data sets to better define the geographic ranges and potential overlap of stocks. Archival, satellite and molecular technologies offer the fisheries research community the new techniques required to resolve the movement patterns and stock structure of highly migratory species. We describe in this paper our use of archival tags on Atlantic bluefin tuna (Thunnus thynnus thynnus). Archival tags provide a record of thynnus ambient and internal body temperature, pressure, and light. From light intensity, augmented with data on sea surface temperature, it is possible to estimate latitude and longitude. In recent years, archival tags have dramatically increased the understanding of the biology of several species of fish. Use of the tags has the potential to address major questions concerning stock structure hypotheses of Atlantic bluefin tunas. We have developed the handling and surgical procedures necessary for internal placement of archival tags in medium and giant bluefin up to 234 kg. Additional studies to examine the survivorship and healing rate of archival tagged fish are being conducted using captive tuna populations in Monterey, California and acoustic and satellite technologies on wild fish. C1 Stanford Univ, Hopkins Marine Stn, Tuna Res & Conservat Ctr, Pacific Grove, CA 93950 USA. Monterey Bay Aquarium Res Inst, Tuna Res & Conservat Ctr, Monterey, CA USA. NOAA, SE Fisheries Sci Ctr, US Dept Commerce, Miami, FL USA. RP Block, BA (reprint author), Stanford Univ, Hopkins Marine Stn, Tuna Res & Conservat Ctr, Pacific Grove, CA 93950 USA. NR 27 TC 59 Z9 61 U1 0 U2 7 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 1998 VL 32 IS 1 BP 37 EP 46 PG 10 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA ZP227 UT WOS:000073730700006 ER PT J AU Levin, I Bendersky, LA Vanderah, TA Roth, RS Stafsudd, OM AF Levin, I Bendersky, LA Vanderah, TA Roth, RS Stafsudd, OM TI A series of incommensurately modulated A(n)B(n)O(3n+2) phases in the SrTiO3-Sr2Nb2O7 quasibinary system SO MATERIALS RESEARCH BULLETIN LA English DT Article DE oxides; electronic materials; electron microscopy; X-ray diffraction; dielectric properties ID CRYSTAL-STRUCTURE; ELECTRON-MICROSCOPY; SR2NB2O7; DIFFRACTION AB A series of structurally related phases A(n)B(n)O(3n+2) with A = Sr2+ and B = (Ti4+,Nb5+) have been prepared. Members of the homologous series with n = 4, 5, 6, 7, and noninteger values between 4 and 5 were characterized by high-resolution electron microscopy/transmission electron microscopy, bulk X-ray powder diffraction, and capacitive measurements of relative permittivities and their temperature coefficients. The structures of these compounds feature distorted perovskite-like slabs sliced parallel to the cubic (110) plane. For members of the series found at integral values, n indicates the width of the slabs (in number of [BO6] octahedra). Samples at nonintegral values of n between 4 and 5 exhibited "line structures," i.e., ordered intergrowths of the n = 4 and n = 5 structures. For these samples, n indicates the average width of the perovskite-like slabs. The compounds share a basic orthorhombic unit cell with a approximate to 3.9 Angstrom, c approximate to 5.6 Angstrom, and a long b dimension that increases incrementally as the width of the slabs increases. High resolution electron microscopy indicated that all of the compounds are incommensurately modulated along the shortest 3.9 Angstrom cell dimension. These effects were not apparent in the bulk X-ray powder diffraction patterns. Experimental X-ray powder patterns indexed with the orthorhombic subcells are given for the new compounds with n = 4.33, 6, and 7, i.e., Sr4.33Ti0.33Nb4O15, Sr6Ti2Nb4O20, and Sr7Ti3Nb4O23. Preliminary capacitive measurements from 100 Hz to 5 MHz of relative permittivities and temperature coefficients indicated little frequency dependence but some unusual differences for successive members of the series, despite their crystal-chemical similarities. (C) 1998 Elsevier Science Ltd. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Calif Los Angeles, Sch Engn, Los Angeles, CA 90095 USA. RP Vanderah, TA (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Levin, Igor/F-8588-2010 NR 23 TC 15 Z9 15 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-5408 J9 MATER RES BULL JI Mater. Res. Bull. PD MAR PY 1998 VL 33 IS 3 BP 501 EP 517 DI 10.1016/S0025-5408(97)00245-6 PG 17 WC Materials Science, Multidisciplinary SC Materials Science GA ZC165 UT WOS:000072547300015 ER PT J AU Soares, CG Halpern, DG Wang, CK AF Soares, CG Halpern, DG Wang, CK TI Calibration and characterization of beta-particle sources for intravascular brachytherapy SO MEDICAL PHYSICS LA English DT Article DE beta particles; extrapolation chamber; intravascular brachytherapy; Monte Carlo calculations; radiochromic film AB The calibration of a catheter-based system to be used for therapeutic radiation treatment to prevent restenosis following interventional coronary procedures is described. The primary dosimetry was performed ionometrically using an extrapolation chamber equipped with a l-mm diameter collecting electrode to measure absorbed dose in tissue equivalent plastic at a depth of 2 mm. These results are compared with measurements with radiochromic dye film, which is also used to characterize sources for axial and trans-axial uniformity, and to determine dose distributions at various depths. A protocol for dose calculation based on that of AAPM TG43 is suggested for these sources, and examples of its use are given for the calculation of the enhancement effect on dose rate from a single seed source due to neighboring seeds. Monte Carlo calculations were also performed to validate the measured results. (C) 1998 American Association of Physicists in Medicine. C1 NIST, Gaithersburg, MD 20899 USA. Novoste Corp, Atlanta, GA USA. Georgia Inst Technol, Atlanta, GA 30332 USA. RP Soares, CG (reprint author), NIST, Gaithersburg, MD 20899 USA. EM chris.wang@me.gatech.edu NR 12 TC 83 Z9 84 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD MAR PY 1998 VL 25 IS 3 BP 339 EP 346 DI 10.1118/1.598204 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZC355 UT WOS:000072569500014 PM 9547501 ER PT J AU Phelps, JM AF Phelps, JM TI Cross-section sample preparation of a free-standing thin-film coupon for transmission electron microscopy analysis SO MICROSCOPY AND MICROANALYSIS LA English DT Article DE cross section; free-standing thin film; sample preparation; transmission electron microscopy AB A method for preparing a cross-section sample from a free-standing thin-film coupon suitable for transmission electron microscopy analysis has been successfully developed. The free-standing coupon presented a significant challenge for the preparation of a cross-section sample. A slack consisting of a silicon wafer, thin-film coupon, and glass coverslip was epoxied together, providing both support for thin film and enough surface area to handle the specimen during the sample preparation procedure. The tripod polisher wedge technique was used to thin the cross-section sample to 2 to 5 mu m in thickness. This produced a sample with the required structural integrity. Final thinning was accomplished using an ion mill. This technique showed no artifacts introduced from the sample preparation procedure. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80303 USA. RP Phelps, JM (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, 325 Broadway, Boulder, CO 80303 USA. NR 6 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD MAR-APR PY 1998 VL 4 IS 2 BP 128 EP 132 PG 5 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA ZQ328 UT WOS:000073847500003 ER PT J AU Birnbaum, G Buechele, A Jiang, T Joslin, CG Goldman, S AF Birnbaum, G Buechele, A Jiang, T Joslin, CG Goldman, S TI Far infrared absorption in liquid methane: experiment and theory SO MOLECULAR PHYSICS LA English DT Article ID COLLISION-INDUCED ABSORPTION; LINEAR-MOLECULES; INDUCED SPECTRA; OCTUPOLE AB The far infrared absorption of liquid methane was measured in the frequency range 30-550 cm(-1) at four temperatures from 91.2 K, near the freezing point, to 122.2 K. The zero, first and second spectral moments were obtained from these measurements and compared with theoretical values. Induction by the octopole and hexadecapole moments of methane was supplemented by an empirical anisotropic overlap induction mechanism. Agreement between theoretical and experimental spectral moments was generally in the range of 10-20%. The computed spectral moments were corrected for quantum effects; with these corrections the agreement with experimental moments improved. The theoretical spectral moments were used to evaluate parameters in an empirical translational line shape in the computation of the overall band shape of the far infrared spectrum. Because the band shape is dominated by the free rotational motion of methane, the exact functional form of the line shape function is not of paramount significance, except at very low frequencies and in the far high frequency wing. The discrepancy between the computed and measured spectra increases with decreasing temperature, with theory increasingly underestimating the experiment. Reasons for discrepancies between theory and experiment are presented. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Catholic Univ Amer, Vitreous State Lab, Washington, DC 20064 USA. Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. Univ Guelph, Guelph Waterloo Program Grad Work Phys, Guelph, ON N1G 2W1, Canada. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Birnbaum, G (reprint author), Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NR 29 TC 4 Z9 4 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD MAR PY 1998 VL 93 IS 4 BP 573 EP 581 DI 10.1080/002689798168907 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZA440 UT WOS:000072363500005 ER PT J AU Atkins, NT Wakimoto, RM Ziegler, CL AF Atkins, NT Wakimoto, RM Ziegler, CL TI Observations of the finescale structure of a dryline during VORTEX 95 SO MONTHLY WEATHER REVIEW LA English DT Article ID PLANETARY BOUNDARY-LAYER; MOBILE SOUNDING OBSERVATIONS; DOPPLER WEATHER RADAR; SEA-BREEZE FRONT; CONVECTIVE STORMS; CONVERGENCE LINES; OKLAHOMA DRYLINE; ROLL VORTICES; DUAL-DOPPLER; TEXAS STORM AB The three-dimensional finescale structure of a dryline observed over the Texas panhandle during the Verification of the Origins in Tornadoes Experiment (VORTEX) on 6 May 1995 is presented. High-resolution observations documenting dryline evolution were collected from midafternoon while it moved slowly eastward until late afternoon as it retrogressed back to the west. Dryline variability in the horizontal along-line direction was revealed by airborne Doppler radar observations from the National Center for Atmospheric Research Electra Doppler radar and ground-based measurements from the nearby WSR-88D at Amarillo, Texas. This variability was created as the dryline interacted with horizontal convective roils forming west of the dryline. The rolls intersected the dryline at periodic locations creating radar reflectivity and vertical velocity maxima. More importantly, clouds initiated at these intersection points. Additional dryline variability was generated through the interaction of the low-level flow with the local topography. The kinematic and thermodynamic characteristics of the leading edge of the dryline circulation closely resembles those of laboratory and atmospheric density currents such as the sea breeze. A comparison between the observed and calculated dryline propagation speeds suggests that the Row-force balance between the cross-frontal acceleration and the density gradient, which exists for density currents, occurs only on the horizontal scale of the leading edge (2-5 km) of the dryline circulation. C1 Natl Ctr Atmospher Res, Mesoscale & Microscale Meteorol Div, Adv Study Program, Boulder, CO 80307 USA. Univ Calif Los Angeles, Dept Atmospher Sci, Los Angeles, CA 90024 USA. NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Atkins, NT (reprint author), Lyndon State Coll, Dept Meteorol, Lyndonville, VT 05851 USA. EM atkinsn@queen.lsc.vsc.edu NR 90 TC 71 Z9 72 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAR PY 1998 VL 126 IS 3 BP 525 EP 550 DI 10.1175/1520-0493(1998)126<0525:OOTFSO>2.0.CO;2 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZA857 UT WOS:000072409000001 ER PT J AU Klimowski, BA Hjelmfelt, MR Bunkers, MJ Sedlacek, D Johnson, LR AF Klimowski, BA Hjelmfelt, MR Bunkers, MJ Sedlacek, D Johnson, LR TI Hailstorm damage observed from the GOES-8 satellite: The 5-6 July 1996 Butte-Meade storm SO MONTHLY WEATHER REVIEW LA English DT Article C1 Natl Weather Serv Off, Rapid City, SD 57701 USA. S Dakota Sch Mines & Technol, Rapid City, SD USA. RP Klimowski, BA (reprint author), Natl Weather Serv Off, 300 E Signal Dr, Rapid City, SD 57701 USA. NR 8 TC 15 Z9 15 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAR PY 1998 VL 126 IS 3 BP 831 EP 834 DI 10.1175/1520-0493(1998)126<0831:HDOFTG>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZA857 UT WOS:000072409000018 ER PT J AU Palmer, AJ Fairall, CW Kropfli, RA AF Palmer, AJ Fairall, CW Kropfli, RA TI Deterministic chaos at the ocean surface: applications and interpretations SO NONLINEAR PROCESSES IN GEOPHYSICS LA English DT Article ID GRAVITY-WAVES; DIMENSION; CLUTTER; WINDS; SEA AB Ocean surface, grazing-angle radar backscatter data from two separate experiments, one of which provided coincident time series of measured surface winds, were found to exhibit signatures of deterministic chaos. Evidence is presented that the lowest dimensional underlying dynamical system responsible for the radar backscatter chaos is that which governs the surface wind turbulence. Block-averaging time was found to be an important parameter for determining the degree of determinism in the data as measured by the correlation dimension, and by the performance of an artificial neural network in retrieving wind and stress from the radar returns, and in radar detection of an ocean internal wave. The correlation dimensions are lowered and the performance of the deterministic retrieval and detection algorithms are improved by averaging out the higher dimensional surface wave variability in the radar returns. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. RP Palmer, AJ (reprint author), NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. NR 23 TC 3 Z9 3 U1 0 U2 0 PU EUROPEAN GEOPHYSICAL SOCIETY PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1023-5809 J9 NONLINEAR PROC GEOPH JI Nonlinear Process Geophys. PD MAR PY 1998 VL 5 IS 1 BP 13 EP 25 PG 13 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 247MH UT WOS:000083224200002 ER PT J AU Hunt, FY AF Hunt, FY TI Unique ergodicity and the approximation of attractors and their invariant measures using Ulam's method SO NONLINEARITY LA English DT Article ID TRANSFORMATIONS; DENSITIES; STABILITY AB Asymptotically stable attractors supporting an invariant measure, for which the ergodic theorem holds almost everywhere with respect to Lebesgue measure, can be approximated by a space!discretization procedure called Ulam's method. As an application of this result we propose the use of this method to approximate the 'chaotic' attractors of flows in lower dimensions. A Monte Carlo implementation makes this feasible. The approximation method can be extended to attractors whose neighbourhoods contain positively invariant compact sets called blocks. Note that such attractors can fail to have open basins of attraction. When the attractor is uniquely ergodic, We also prove the weak convergence of the approximate measures constructed by the method and as an application, we show the weak convergence of Ulam's method for the logistic map at the Feigenbaum parameter value. More generally, using the work of Buescu and Stewart on transitive attractors of continuous maps, we prove weak convergence of the approximate measures and convergence of their supports to classes of Lyapounov stable attracting Canter sets. C1 NIST, Math & Computat Sci Div, Gaithersburg, MD 20899 USA. RP Hunt, FY (reprint author), NIST, Math & Computat Sci Div, Gaithersburg, MD 20899 USA. NR 21 TC 8 Z9 8 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0951-7715 J9 NONLINEARITY JI Nonlinearity PD MAR PY 1998 VL 11 IS 2 BP 307 EP 317 DI 10.1088/0951-7715/11/2/007 PG 11 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA ZC111 UT WOS:000072541000007 ER PT J AU Karahalil, B Girard, PM Boiteux, S Dizdaroglu, M AF Karahalil, B Girard, PM Boiteux, S Dizdaroglu, M TI Substrate specificity of the Ogg1 protein of Saccharomyces cerevisiae: excision of guanine lesions produced in DNA by ionizing radiation or hydrogen peroxide metal ion generated free radicals SO NUCLEIC ACIDS RESEARCH LA English DT Article ID COLI ENDONUCLEASE-III; ESCHERICHIA-COLI; MAMMALIAN CHROMATIN; OXIDATIVE DAMAGE; FPG PROTEINS; GLYCOSYLASE; REPAIR; 8-OXOGUANINE; BASES; RESIDUES AB We have investigated the substrate specificity of the Ogg1 protein of Saccharomyces cerevisiae (yOgg1 protein) for excision of modified DNA bases from oxidatively damaged DNA substrates using gas chromatography/isotope dilution mass spectrometry, Four DNA substrates prepared by treatment with H2O2/Fe(III)-EDTA/ascorbic acid, H2O2/Cu(II) and gamma-irradiation under N2O or air were used, The results showed that 8-hydroxyguanine (8-OH-Gua) and 2,6-diamino-4-hydroxy-5-formamidopyrimid (Fapy-Gua) were efficiently excised from DNA exposed to ionizing radiation in the presence of N2O or air, On the other hand, 8-OH-Gua and FapyGua were not excised from H2O2/Fe(III)-EDTA/ascorbic acid-treated and H2O2/Cu(II)-treated DNA respectively, Fourteen other lesions, including the adenine lesions 8-hydroxyadenine and 4,6-diamino-5-formamidopyrimidine, were not excised from any of the DNA substrates. Kinetics of excision significantly depended on the nature of the damaged DNA substrates. The findings suggest that, in addition to 8-OH-Gua, FapyGua may also be a primary substrate of yOgg1 in cells, The results also show significant differences between the substrate specificities of yOgg1 protein and its functional analog Fpg protein in Escherichia coli. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Gazi Univ, Fac Pharm, Dept Toxicol, Ankara, Turkey. CEA, Radiobiol Lab, DNA, DSV,DRR,UMR217,CNRS, F-92265 Fontenay Aux Roses, France. RP Dizdaroglu, M (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. EM miral@nist.gov NR 34 TC 100 Z9 102 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD MAR 1 PY 1998 VL 26 IS 5 BP 1228 EP 1232 DI 10.1093/nar/26.5.1228 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZA438 UT WOS:000072363300014 PM 9469830 ER PT J AU Diddams, SA Eaton, HK Zozulya, AA Clement, TS AF Diddams, SA Eaton, HK Zozulya, AA Clement, TS TI Amplitude and phase measurements of femtosecond pulse splitting in nonlinear dispersive media SO OPTICS LETTERS LA English DT Article AB Frequency-resolved optical gating is used to characterize the propagation of intense femtosecond pulses in a nonlinear, dispersive medium. The combined effects of diffraction, normal dispersion, and cubic nonlinearity lead to pulse splitting. The role of the phase of the input pulse is studied. The results are compared with the predictions of a three-dimensional nonlinear Schrodinger equation. (C) 1998 Optical Society of America. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Diddams, SA (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Clement, Tracy/A-8885-2008; Diddams, Scott/L-2819-2013 NR 16 TC 70 Z9 70 U1 0 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD MAR 1 PY 1998 VL 23 IS 5 BP 379 EP 381 DI 10.1364/OL.23.000379 PG 3 WC Optics SC Optics GA ZA057 UT WOS:000072324400023 PM 18084518 ER PT J AU Neuman, JA Gallagher, A AF Neuman, JA Gallagher, A TI Effects of alignment on strontium energy pooling collisions SO PHYSICAL REVIEW A LA English DT Article ID CROSS-SECTIONS AB The dependence of energy pooling cross sections on the alignment of atomic angular momentum with respect to the collision axis is investigated. In a vapor cell, excitation with counter-propagating polarized laser beams that define the collision axis prepares aligned strontium atoms in the 5s5p P-3(1) level. Excited-state energy pooling collision products from the endothermic 5s5p P-3(1) + 5s5p P-3(1) --> 5s6s S-1(0) + 5s(2 1)S(0) reaction and the exothermic 5s5p P-3(1) + 5s5p P-3(1) --> 5s5p P-1(1) + 5s(2 1)S(0) reaction are studied. Alignment effects are studied as a function of collision energy, using pulsed laser excitation followed by delayed fluorescence detection to lower the transverse collision velocity and laser detuning to vary the collision velocity in the laser-beam direction. The rate coefficient for energy transfer to the 6 S-1(0) state is enhanced by 38+/-13% when the M-J alignment of the collision partners is perpendicular to the collision axis and parallel to each other compared to when there is no alignment of the collision partners. No alignment dependence is observed for energy transfer to the 5 P-1(1) state. This experiment offers the unique capability of simultaneously and independently controlling collision velocity and angular momentum alignment. [S1050-2947(98)03803-7]. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Neuman, JA (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Neuman, Andy/A-1393-2009 OI Neuman, Andy/0000-0002-3986-1727 NR 7 TC 1 Z9 1 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 MAR PY 1998 VL 57 IS 3 BP 2231 EP 2234 DI 10.1103/PhysRevA.57.2231 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZB155 UT WOS:000072441900099 ER PT J AU Bindra, C Nalimova, VA Sklovsky, DE Kamitakahara, WA Fischer, JE AF Bindra, C Nalimova, VA Sklovsky, DE Kamitakahara, WA Fischer, JE TI Statics and dynamics of interlayer interactions in the dense high-pressure graphite compound LiC2 SO PHYSICAL REVIEW B LA English DT Article ID INTERCALATION COMPOUNDS; THERMAL-EXPANSION; ALKALI; LITHIUM; PHONONS AB Reaction of Li with graphite at high pressures yields LiC2, three times as dense in Li than the ambient-pressure graphite intercalation compound LiC6 We study the stability of this unusually high Li density against Coulomb repulsion by neutron and x-ray scattering. Surprisingly, parameters which should be sensitive to interlayer interactions are quite similar to the LiC6 values: c-axis compressibility kappa(c) = 1.43 x 10-(12) cm(2)/dyn, sound velocity v(s)=5.1 x 10(5) cm/s, zone-boundary acoustic-phonon energy = 18.5 eV, and slightly higher thermal expansion alpha(c)=66 x 10(-6)/K (300-450 K). Moreover, both compounds are yellow in reflection, implying that the delocalized charge densities are comparable. These and other results are consistent with partially covalent in-plane Li-Li bonds, i.e., partial charge transfer to the graphene layers, as opposed to the more conventional ionic picture which applies to most alkali-graphite intercalation compounds. C1 Univ Penn, Dept Phys, Philadelphia, PA 19104 USA. Univ Penn, Res Struct Matter Lab, Philadelphia, PA 19104 USA. Moscow MV Lomonosov State Univ, Dept Chem, Moscow 119899, Russia. Natl Inst Stand & Technol, Div Reactor Radiat, Gaithersburg, MD 20899 USA. Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. RP Bindra, C (reprint author), Univ Penn, Dept Phys, Philadelphia, PA 19104 USA. NR 25 TC 11 Z9 11 U1 0 U2 7 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 1 PY 1998 VL 57 IS 9 BP 5182 EP 5190 DI 10.1103/PhysRevB.57.5182 PG 9 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600046 ER PT J AU Zaliznyak, IA Dender, DC Broholm, C Reich, DH AF Zaliznyak, IA Dender, DC Broholm, C Reich, DH TI Tuning the spin Hamiltonian of Ni(C2H8N2)(2)NO2ClO4 by external pressure: A neutron-scattering study SO PHYSICAL REVIEW B LA English DT Article ID DIMENSIONAL HEISENBERG-ANTIFERROMAGNET; HALDANE-GAP SYSTEM; CHAIN; EXCITATIONS; ANISOTROPY; MODEL; TEMPERATURE; AGVP2S6; STATE; NENP AB We report an inelastic neutron-scattering study of antiferromagnetic spin dynamics in the Haldane chain compound Ni(C2H8N2)(2)NO2ClO4 (NENP) under external hydrostatic pressure P = 2.5 GPa. At ambient pressure, the magnetic excitations in NENP are dominated by a long-lived triplet mode with a gap that is split by orthorhombic crystalline anisotropy into a lower doublet centered at Delta(perpendicular to)approximate to 1.2 meV and a singlet at Delta(parallel to)approximate to 2.5 meV. With pressure we observe appreciable shifts in these levels, which move to Delta(perpendicular to)(2.5 GPa) approximate to 1.45 meV and Delta(parallel to)(2.5 GPa)approximate to 2.2 meV. The dispersion of these modes in the crystalline (c) over cap direction perpendicular to the chain was measured here and can be accounted for by an interchain exchange J(c)'approximate to 3x10(-4)J that changes only slightly with pressure. Since the average gap value Delta(H) approximate to 1.64 meV remains almost unchanged with P, we conclude that in NENP the application of external pressure does not affect the intrachain coupling J appreciably, but does produce a significant decrease of the single-ion anisotropy constant from D/J = 0.16(2) at ambient pressure to D/J = 0.09(1) at P = 2.5 GPa. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. PL Kapitza Phys Problems Inst, Moscow 117334, Russia. RP Zaliznyak, IA (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RI Broholm, Collin/E-8228-2011; Zaliznyak, Igor/E-8532-2014 OI Broholm, Collin/0000-0002-1569-9892; Zaliznyak, Igor/0000-0002-9886-3255 NR 28 TC 14 Z9 14 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 MAR 1 PY 1998 VL 57 IS 9 BP 5200 EP 5204 DI 10.1103/PhysRevB.57.5200 PG 5 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600048 ER PT J AU Wong-Ng, W AF Wong-Ng, W TI Report of the 1997 Materials Research Society Annual Meeting SO POWDER DIFFRACTION LA English DT Editorial Material C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. RP Wong-Ng, W (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD MAR PY 1998 VL 13 IS 1 BP 63 EP 64 PG 2 WC Materials Science, Characterization & Testing SC Materials Science GA ZC827 UT WOS:000072622100015 ER PT J AU Westwater, ER Han, Y Irisov, VG Leuskiy, VY Trokhimovski, YG Fairall, CW Jessup, AT AF Westwater, ER Han, Y Irisov, VG Leuskiy, VY Trokhimovski, YG Fairall, CW Jessup, AT TI Sea-air and boundary layer temperatures measured by a scanning 5-mm-wavelength radiometer: Recent results SO RADIO SCIENCE LA English DT Article ID ATMOSPHERIC STABILITY; WIND-SPEED; DEPENDENCE AB A scanning 5-mm-wavelength (60 GHz) radiometer was deployed during two recent experiments. The first was in September-October in 1995 when the Environmental Technology Laboratory conducted the Coastal Ocean Probing Experiment off the Oregon coast. During this experiment the scanning radiometer was deployed on the Floating Instrument Platform, a research vessel operated by the Scripps Institution of Oceanography. Ground truth for the radiometer was provided by two independent in situ and infrared measurements of the ocean surface temperature; ground truth for air temperature was also provided by two in situ measurements at 0.5 and 12 m above the ocean surface. The second experiment was during September 10-30, 1996, at the Department of Energy's Atmospheric Radiation Measurement Program's Cloud and Radiation Testbed site near Lament, Oklahoma. Here ground truth for derived quantities consisted of 3-hourly radiosonde releases and measurements at 25 and 60 m from a meteorological tower. The results of the experiments indicate that the scanning radiometer yields accuracies of the order of 0.4 degrees C rms for sea-air temperature difference and accuracies in temperature of better than 0.7 degrees C rms at altitudes below 60 m. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Environm Technol Lab, Boulder, CO 80309 USA. NOAA, ERL, Environm Technol Lab, Boulder, CO 80303 USA. Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA. RP Westwater, ER (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Environm Technol Lab, R-E-ET1,325 Broadway, Boulder, CO 80309 USA. RI Han, Yong/F-5590-2010; Jessup, Andrew/E-5625-2017 OI Han, Yong/0000-0002-0183-7270; NR 15 TC 9 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD MAR-APR PY 1998 VL 33 IS 2 BP 291 EP 302 DI 10.1029/97RS02747 PG 12 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA ZE395 UT WOS:000072788300012 ER PT J AU Wang, YP Alishouse, JC Ferraro, RR Song, R AF Wang, YP Alishouse, JC Ferraro, RR Song, R TI Estimation of midlatitude rainfall parameters from satellite microwave radiometers using the area-time integral concept SO RADIO SCIENCE LA English DT Article ID CONVECTIVE RAINFALL; SNOW COVER; WSR-88D; PRECIPITATION; ALGORITHMS AB Weather Surveillance Radar-1988 Doppler (WSR-88D) level II data and special sensor microwave imager (SSM/I) brightness temperature data were collocated to further investigate the use of the area-time integral (ATI) technique in the estimation of satellite microwave rainfall amount based on the storm area coverage information. The concept of a strong relationship between the areal extent and time duration of precipitation and the total amount of precipitation seems to have been extant in radar meteorology for some time, primarily in the tropics. This strong relationship is again demonstrated using WSR-88D data. However, it was found that this correlation strongly depends on the Z-R relationship used in computing rain rate from radar reflectivity data. This study conducted two experiments: (1) using one Z-R relationship for the whole storm rain area and (2) separating rain into two parts, convective and stratiform, and applying two Z-R relationships. The area-wide average rain rate from the storm as viewed from the satellite was calculated from the ATI formalism based on the relationships developed from the WSR-88D data, The estimates were compared with the SSM/I 85-GHz scattering algorithm estimates and verified using Next Generation Weather Radar (NEXRAD) observations and hourly rain gauge measurements. The results reveal that the ATI technique can be used as an alternative approach for determining and validating satellite precipitation parameters, The separation of convective and stratiform precipitation improved the relationship between the area-wide average rain rate and fractional rainfall area and consequently improved the accuracy of satellite rainfall estimation. C1 Natl Environm Satellite Data & Informat Serv, NOAA, Off Res & Applicat, Camp Spring, MD 20746 USA. Hughes STX Corp, Lanham, MD 20706 USA. Syst Engn & Secur Inc, Greenbelt, MD USA. RP Wang, YP (reprint author), Natl Environm Satellite Data & Informat Serv, NOAA, Off Res & Applicat, 5200 Auth Rd,Room 703, Camp Spring, MD 20746 USA. RI Ferraro, Ralph/F-5587-2010 OI Ferraro, Ralph/0000-0002-8393-7135 NR 29 TC 3 Z9 3 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD MAR-APR PY 1998 VL 33 IS 2 BP 317 EP 333 DI 10.1029/97RS03654 PG 17 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA ZE395 UT WOS:000072788300014 ER PT J AU Solheim, F Godwin, JR Westwater, ER Han, Y Keihm, SJ Marsh, K Ware, R AF Solheim, F Godwin, JR Westwater, ER Han, Y Keihm, SJ Marsh, K Ware, R TI Radiometric profiling of temperature, water vapor and cloud liquid water using various inversion methods SO RADIO SCIENCE LA English DT Article AB We have developed a tunable temperature profiler based on a highly stable synthesizer that can observe at multiple frequencies on the shoulder of the 60-GHz atmospheric oxygen feature. We are developing a similar radiometer to obtain the vertical distribution of water vapor by making observations on the pressure-broadened water vapor line from 22 to 29 GHz. Information on cloud liquid water profiles is also contained in these two wave bands. Various mathematical retrieval methods for temperature, water vapor, and cloud liquid water profiles were tested based on these radiometer designs. These include neural networking, Newtonian iteration of statistically retrieved profiles, and Bayesian "most probable" retrievals. On the basis of realistic radiometer errors and performance, very good retrieval capability is demonstrated. The performance of the various retrieval methods are presented and compared. Examples of profile retrievals are also presented. Data were not binned into seasons to reduce computer time; better retrieval results for all methods would be expected with binning. C1 Radiometr Corp, Boulder, CO 80301 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Corp Atmospher Res, Boulder, CO 80307 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Solheim, F (reprint author), Radiometr Corp, 2898 30th St, Boulder, CO 80301 USA. EM sol-heim@radiometrics.com; yhan@etl.noaa.gov; stephen.j.keihm@ccmail.jpl.nasa.gov; ware@ucar.edu RI Han, Yong/F-5590-2010 OI Han, Yong/0000-0002-0183-7270 NR 6 TC 137 Z9 150 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD MAR-APR PY 1998 VL 33 IS 2 BP 393 EP 404 DI 10.1029/97RS03656 PG 12 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA ZE395 UT WOS:000072788300018 ER PT J AU Snider, JB Hazen, DA AF Snider, JB Hazen, DA TI Surface-based radiometric observations of water vapor and cloud liquid in the temperate zone and in the tropics SO RADIO SCIENCE LA English DT Article ID STORMS; ASTEX AB Observations of water vapor and cloud liquid made with surface-based microwave radiometers operating near 20, 23, 31, and 90 GHz are described. Measurements were made at several continental locations in the United States, an island and ship in the northern Atlantic Ocean, and an island and ship in the tropical western Pacific Ocean. The instrumentation and statistical inversion technique employed to retrieve vapor and liquid values from radiometric brightnesses are reviewed. Various aspects of the water vapor and cloud liquid data are compared as a function of geographic location. The diurnal and seasonal variability of water vapor, cloud liquid, cloud fraction, and infrared sky brightness temperature observed during a 1-year period at an island in the North Atlantic Ocean are also presented. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. NOAA, ERL, Environm Technol Lab, Boulder, CO 80303 USA. RP Snider, JB (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, R-E-ET6,325 Broadway, Boulder, CO 80303 USA. EM jsnider@etl.noaa.gov; dhazen@etl.noaa.gov NR 16 TC 10 Z9 10 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD MAR-APR PY 1998 VL 33 IS 2 BP 421 EP 432 DI 10.1029/97RS02048 PG 12 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA ZE395 UT WOS:000072788300021 ER PT J AU Unganai, LS Kogan, FN AF Unganai, LS Kogan, FN TI Drought monitoring and corn yield estimation in Southern Africa from AVHRR data SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID HIGH-RESOLUTION RADIOMETER; VEGETATION INDEX; SATELLITE DATA; UNITED-STATES; BURKINA-FASO; NDVI; PRECIPITATION; TEMPERATURE; CALIBRATION; PROFILES AB Drought is one of the major environmental disasters in southern Africa. In recent years, the damage from droughts to the environment and economies of some countries was extensive, and the death toll of livestock and wildlife was unprecedented. Weather data often come from a very sparse meteorological network, incomplete and/or not always available in good time to enable relatively accurate and timely large scale drought detection and monitoring. Therefore, data obtained from the Advanced Very High Resolution Radiometer (AVHRR) sensor on board the NOAA polar-orbiting satellites have been studied as a tool for drought monitoring and climate impact assessment in southern Africa. The AVHRR-based vegetation condition index (VCI) and temperature condition index (TCI) developed recently were used in this study because in other parts of the globe they showed goon results when used for drought detection and tracking, monitoring excessive soil wetness, assessment of weather impacts on vegetation, and evaluation of vegetation health and productivity. The results clearly show that temporal and spatial characteristics of drought in southern Africa can be detected, tracked, and mapped by the VCI and TCI indices. These results were numerically validated by in situ data such as precipitation, atmospheric anomaly fields, and agricultural crop yield. In the later case, it lans found that usable corn yield scenarios can be constructed from the VCI and TCI at approximately 6 (in some regions up to 13) weeks prior to harvest time. These indices can be especially beneficial when used together with ground data. (C) Elsevier Science Inc., 1998. C1 NOAA, Satellite Res Lab, Camp Springs, MD 20746 USA. Drought Monitoring Ctr, Dept Meteorol Serv, Harare, Zimbabwe. RP Kogan, FN (reprint author), NOAA, Satellite Res Lab, Camp Springs, MD 20746 USA. RI Kogan, Felix/F-5600-2010 OI Kogan, Felix/0000-0001-8216-900X NR 53 TC 140 Z9 164 U1 1 U2 31 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD MAR PY 1998 VL 63 IS 3 BP 219 EP 232 DI 10.1016/S0034-4257(97)00132-6 PG 14 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA YX797 UT WOS:000072078900003 ER PT J AU Fahey, AJ AF Fahey, AJ TI Measurements of dead time and characterization of ion counting systems for mass spectrometry SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A method for characterization of electron multiplier-based pulse counting systems is presented. Specific attention is paid to measurement of the counting system dead time. The systems discussed here are typically used to measure the abundance of ions passing through a mass spectrometer. A method for the determination of dead time by measurement of at least two isotopic ratios of an element with at least three isotopes is given. This method differs from the "text book" method typically used to measure the dead time, The theoretical basis for the measurements is given and an example of measurements of Ti isotopes by secondary ion mass spectrometry (SIMS) is shown. Dead time measurements on SIMS instruments can be performed in a few hours of machine time. A brief description of the pulse detection and counting circuit and its operation is also given. Guidelines for the proper measurement of pulse shapes and the determination of reasonable settings for electron multiplier gain, preamplifier gain, and discriminator threshold are also discussed. [S0034-6748(98)01703-1]. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Fahey, AJ (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RI Fahey, Albert/C-5611-2015 NR 12 TC 19 Z9 19 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAR PY 1998 VL 69 IS 3 BP 1282 EP 1288 DI 10.1063/1.1148796 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZC403 UT WOS:000072574500014 ER PT J AU Small, JA AF Small, JA TI The detection of low-intensity peaks in energy dispersive x-ray spectra from particles SO SCANNING LA English DT Article DE automated scanning electron microscopy; particle analysis; energy dispersive x-ray analysis; peak identification AB A critical step in the processing of energy dispersive (EDS) x-ray spectra from the automated scanning electron microscopy (ASEM) analysis of particles is the detection and identification of elemental peaks. Since there are often several hundred to several thousand spectra for each ASEM analysis, it is important that this step operate rapidly and with a minimum of interaction between analyst and the program. For peaks with large peak-to-background (P/B) ratios, most peak-find or peak-fitting methods do a reasonable job even when the spectra have low signal-to-noise (S/N) ratios. The detection of peaks with small P/B ratios is much more problematical. Peak identification and fitting procedures may not work well on low-intensity peaks, particularly in spectra with low S/N ratios. In this study, three procedures for identifying x-ray peaks, with small P/B ratios in spectra with varying S/N ratios, were evaluated. The first procedure was the identification of peaks by human analysts. The results from the analysts were then used to set a benchmark for the performance of two computer-based procedures that included three different qualitative peak identification methods, and one quantitative analysis procedure. The success of the qualitative methods in finding small peaks varied widely. In general, the quantitative analysis procedure performed as well as the best human analysts and was better than the qualitative methods. C1 NIST, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Small, JA (reprint author), NIST, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 USA SN 0161-0457 J9 SCANNING JI Scanning PD MAR PY 1998 VL 20 IS 2 BP 92 EP 98 PG 7 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA ZD016 UT WOS:000072642400005 ER PT J AU Cornell, EA Wieman, CE AF Cornell, EA Wieman, CE TI The Bose-Einstein condensate SO SCIENTIFIC AMERICAN LA English DT Article C1 NIST, Gaithersburg, MD 20899 USA. Univ Colorado, Boulder, CO 80309 USA. RP Cornell, EA (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 4 TC 12 Z9 12 U1 1 U2 7 PU SCI AMERICAN INC PI NEW YORK PA 415 MADISON AVE, NEW YORK, NY 10017 USA SN 0036-8733 J9 SCI AM JI Sci.Am. PD MAR PY 1998 VL 278 IS 3 BP 40 EP 45 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YX866 UT WOS:000072087500024 ER PT J AU Podobedov, VB Weber, A Romero, DB Rice, JP Drew, HD AF Podobedov, VB Weber, A Romero, DB Rice, JP Drew, HD TI Raman scattering in La1-xSrxMnO3 single crystals (x = 0, 0.1, 0.2, 0.3) SO SOLID STATE COMMUNICATIONS LA English DT Article DE insulators/metals; phonons; inelastic light scattering ID TRANSITIONS AB We report polarized Raman spectra of La1-xSrxMnO3 crystals (x = 0, 0.1, 0.2 and 0.3) in the temperature range from 5 K to 300 K. The small distortion of the nearly cubic lattice of doped La1-xSrxMnO3 single crystals results in a structured phonon Raman spectrum which is composed of two parts with different contributions depending on the value of doping. The first part is assigned to the distorted non-cubic perovskite lattice and follows the selection rules for a tetragonal structure. This suggests the possible presence of a tetragonal structure in doped La1-xSrxMnO3 single crystals. The second part is mainly due to the density of vibrational states and is attributed to the second-order Raman scattering. The frequency of the A(1g)-like mode was found to be sensitive to doping but the observed shift is opposite to that expected from the difference in the atomic weight of Sr and La. This mode exhibits also an anomalously large shift of similar to 20 cm(-1) in the temperature range from 5 K to 300 K. A possible explanation of this behaviour is suggested. (C) 1998 Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Russian Acad Sci, Inst Spect, Troitsk 142092, Moscow Region, Russia. RP Podobedov, VB (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 23 TC 43 Z9 44 U1 0 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD MAR PY 1998 VL 105 IS 9 BP 589 EP 593 DI 10.1016/S0038-1098(97)10185-5 PG 5 WC Physics, Condensed Matter SC Physics GA YX112 UT WOS:000072007600009 ER PT J AU Band, YB Trippenbach, M Bryant, GW Julienne, PS AF Band, YB Trippenbach, M Bryant, GW Julienne, PS TI Probing evanescent modes from near-field optical microscopes: propagation into anisotropic media SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 4th International Conference on Near-Field Optics and Related Techniques CY FEB 09-13, 1997 CL JERUSALEM, ISRAEL ID NONISOTROPIC MEDIA AB We describe how to probe the amplitude and polarization of the evanescent modes of light emanating from near-field scanning optical microscopes and Bethe-Bouwkamp holes by placing these structures near anisotropic dispersive media. Evanescent modes have different cut-offs for propagation inside the anisotropic medium as a function of the angles made by their wave vectors and the optic axes of the medium. The electromagnetic field mode amplitudes near the tip can be obtained by varying the orientation of the optic axes relative to the tip. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel. Ben Gurion Univ Negev, Dept Phys, IL-84105 Beer Sheva, Israel. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Band, YB (reprint author), Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 15 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD MAR PY 1998 VL 71 IS 1-4 BP 31 EP 38 DI 10.1016/S0304-3991(97)00104-6 PG 8 WC Microscopy SC Microscopy GA ZF289 UT WOS:000072882600005 ER PT J AU Charba, JP Liu, YJ Hollar, MH Exley, B Belayachi, A AF Charba, JP Liu, YJ Hollar, MH Exley, B Belayachi, A TI Gridded climatic monthly frequencies of precipitation amount for 1-, 3-, and 6-h periods over the conterminous United States SO WEATHER AND FORECASTING LA English DT Article ID MESOSCALE CONVECTIVE COMPLEXES; BOUNDARY-LAYER EVOLUTION; DIURNAL VARIABILITY; MOUNTAINOUS TERRAIN; GREAT-LAKES; FLORIDA; SUMMER; STORMS; MODEL; THUNDERSTORMS AB Gridded fields of monthly mean relative frequency for greater than or equal to 0.10 (2.5), greater than or equal to 0.25 (6.4), greater than or equal to 0.50 (12.7), greater than or equal to 1.00 (25.4), and greater than or equal to 2.00 (50.8) in. (mm) of precipitation have been developed for 1-, 3-, and 6-h periods over the conterminous United States. The frequency fields are analyzed on a rectangular grid with a 20-km mesh. Raw (unsmoothed) frequencies at randomly spaced points were computed from 33 yr (1963-95) of hourly precipitation measurements from approximately 3000 stations composing the U.S. Climatic Hourly Precipitation Network. Initial grids of the raw frequencies were then obtained from objective analyses of the randomly spaced values. The final grids were obtained following the application of smoothing, which was applied spatially over the grid and temporally over consecutive months and consecutive time periods of the day. The smoothing applied for each precipitation category and accumulation period was minimized to retain as much coherent temporal and spatial derail as possible. The detail in the frequencies is greater than that for previous nationwide climatic precipitation analyses of this type. The database was developed for use as a climatological predictor input to a statistically based forecast model for the various categories of precipitation amount, but it should also have other operational or research applications. The monthly frequency fields exhibit known climatic features across the nation and features at small temporal and spatial scales that either have not been previously documented or that clarify those incompletely defined in the published literature. The discussions link both known and new climatic features to physiographic features, such as mountain ridges and valleys, large lakes, and ocean coasts, as well as to the diurnal hearing-cooling cycle. Examples of clarifications of previous findings include the spatial and temporal properties of the eastward migration of summer afternoon precipitation frequency peaks from the Rocky Mountains to the high plains and corresponding aspects of the formation of the Great Plains nocturnal precipitation maximum. New discoveries include a secondary summertime nocturnal precipitation peak in the Texas panhandle, a persistent summer maximum for light precipitation southwest of Lake Superior, and a weak leeshore maximum (minimum) for summertime Lake Michigan precipitation during morning (afternoon) hours. These and other new findings resulted from the fine spatial and temporal scale of the analysis. C1 Natl Weather Serv, Tech Dev Lab, Off Syst Dev, NOAA, Silver Spring, MD 20910 USA. RP Charba, JP (reprint author), Natl Weather Serv, Tech Dev Lab, Off Syst Dev, NOAA, W-OSD24,1325 East West Hwy, Silver Spring, MD 20910 USA. NR 71 TC 7 Z9 7 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1998 VL 13 IS 1 BP 25 EP 57 DI 10.1175/1520-0434(1998)013<0025:GCMFOP>2.0.CO;2 PG 33 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF645 UT WOS:000072917800003 ER PT J AU Johnson, LE Olsen, BG AF Johnson, LE Olsen, BG TI Assessment of quantitative precipitation forecasts SO WEATHER AND FORECASTING LA English DT Article AB This paper reports on an assessment of quantitative precipitation forecasts (QPFs) issued by the Arkansas-Red Basin River Forecast Center during the period May-June 1995. Assessment procedures involved spatial statistical procedures applied to the QPFs and Stage III calibrated radar-rainfall fields, and overlays of these. The QPF estimates were broad regional estimates that corresponded reasonably well to actual storm characteristics over the region. Over smaller areas on the order of 10% of the region (similar to 9000 mi(2)) the character of actual storms departs significantly from the QPF. Embedded storm cells having high intensity rainfall were not well predicted by the QPF. There was indication that QPF skill increased with rainfall magnitude. C1 NOAA, ERL, Forecast Syst Lab, Boulder, CO 80303 USA. Univ Colorado, Denver, CO 80202 USA. Natl Weather Serv, Arkansas Red Basin River Forecast Ctr, Tulsa, OK USA. RP Johnson, LE (reprint author), NOAA, ERL, Forecast Syst Lab, R-E-F56,325 Broadway, Boulder, CO 80303 USA. NR 12 TC 16 Z9 16 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1998 VL 13 IS 1 BP 75 EP 83 DI 10.1175/1520-0434(1998)013<0075:AOQPF>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF645 UT WOS:000072917800005 ER PT J AU Weismueller, JL Zubrick, SM AF Weismueller, JL Zubrick, SM TI Evaluation and application of conditional symmetric instability, equivalent potential vorticity, and frontogenetic forcing in an operational forecast environment SO WEATHER AND FORECASTING LA English DT Article ID UNITED-STATES; SNOWSTORM; STABILITY; MIDWEST AB The related fields of equivalent potential temperature (theta(e)), geostrophic momentum (M-g), equivalent potential vorticity (EPV), and frontogenetic forcing were computed, analyzed, and evaluated for two mid-Atlantic states snowstorms in which conditional symmetric instability (CSI) is believed to have been present. Observed data as well as model gridded data were used with the National Weather Service PC-based Gridded Information Display and Diagnostic System in evaluating the event, thereby providing both initial and model forecast fields. A brief physical and historical review of CSI is provided as a basis for better understanding and increased proper application of this technique into operational forecasting. The implications of CSI for the operational forecaster are then demonstrated through a diagnosis of events occurring in Maryland and Virginia on 26 February 1993 and 30 January 1995, in which precipitation banding related to frontogenetic forcing and CSI are believed to have occurred. The intent here is to demonstrate that it is possible to improve short-range forecasts of CSI-related precipitation in an operational forecast environment through improved techniques for the recognition and evaluation of CSI via model-derived forecast fields, augmented with WSR-88D radar and other new observing systems. Vertical cross sections of forecast M-g, theta(e), layer mean geostrophic frontogenesis, and EPV fields were constructed and revealed regions of conditional symmetric instability and frontogenetic forcing that were nearly coincident with the observed enhanced snow bands. The availability of gridded model output and the increased capability for quickly manipulating those datasets in real time have now enhanced the potential for improved forecasts of CSI-related phenomena in operational forecast settings. C1 Natl Weather Serv, Baltimore Washington Forecast Off, Sterling, VA 20166 USA. RP Natl Weather Serv, Baltimore Washington Forecast Off, 44087 Weather Serv Rd, Sterling, VA 20166 USA. EM James.Wiesmueller@noaa.gov NR 33 TC 3 Z9 3 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 EI 1520-0434 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1998 VL 13 IS 1 BP 84 EP 101 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF645 UT WOS:000072917800006 ER PT J AU Doswell, CA Ramis, C Romero, R Alonso, S AF Doswell, CA Ramis, C Romero, R Alonso, S TI A diagnostic study of three heavy precipitation episodes in the western Mediterranean region SO WEATHER AND FORECASTING LA English DT Article ID NUMERICAL-SIMULATION; MESO-BETA; INTERPOLATION; CONVECTION; SYSTEM AB A diagnostic evaluation of three project ANOMALIA case studies involving heavy precipitation in the western Mediterranean region has been carried out. The evaluation shows the unique characteristics of each event, as well as some limited similarities. Heavy precipitation events in the western Mediterranean region typically occur downstream of a significant cyclone aloft (often, but not always, exhibiting "cutoff" cyclone characteristics), but important structural and evolutionary differences are found among these cases. At low levels, a long fetch of flow over the Mediterranean Sea frequently interacts with terrain features to produce persistent heavy precipitation. Although most heavy precipitation events occur during the fall season, they can develop at other times. In the first case, the synoptic-scale environment produced low static stability and substantial storm-relative environmental helicity, thereby supporting both heavy rain in the vicinity of Valencia on mainland Spain and on Ibiza in the Balearic Islands, as well as a tornado at Menorca in the Balearic Islands on 7-9 October 1992. The second case involved a slow-moving cyclone that destabilized the stratification and produced several days of heavy precipitation over the period 31 January-6 February 1993. In the third case, in the Italian Piedmont region on 5-6 November 1994, the heavy precipitation included a nonconvective component, with moist but relatively stable air impinging on steep terrain gradients. A set of basic diagnostic tools is applied to the cases, and it is shown that anything but a superficial diagnosis of each case requires flexibility in selecting diagnostic tools. The ways by which heavy precipitation is created can vary substantially from case to case and in different parts of the world; however, there is a common thread. Heavy precipitation is the result of moist, low-level air ascending rapidly, so any diagnosis aimed at forecasting heavy precipitation needs to address the following: vertical motion, static stability, moisture supply, and orographic effects (when appropriate). Forecasting implications of the cases are discussed, with the emphasis on considering these physically relevant processes. C1 NOAA, Environm Res Labs, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Balearic Isl, Geophys Fluid Dynam Grp, E-07071 Palma de Mallorca, Spain. RP Doswell, CA (reprint author), NOAA, Environm Res Labs, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. EM doswell@nssl.noaa.gov RI Doswell III, Charles/E-7662-2010 NR 36 TC 112 Z9 112 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1998 VL 13 IS 1 BP 102 EP 124 DI 10.1175/1520-0434(1998)013<0102:ADSOTH>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF645 UT WOS:000072917800007 ER PT J AU Thompson, RL AF Thompson, RL TI Eta model storm-relative winds associated with tornadic and nontornadic supercells SO WEATHER AND FORECASTING LA English DT Article ID SIMULATED CONVECTIVE STORMS; ROTATION; THUNDERSTORMS; MESOCYCLONES; PROPAGATION; HELICITY AB A conceptual model for sustained low-level mesocyclones is tested as a tornado forecast tool with observations and forecasts from the operational Eta Model. In the conceptual model, a balance between low-level storm inflow and outflow allows the development of a persistent low-level mesocyclone along the rear flank of a supercell thunderstorm, owing largely to the strength of the midlevel storm-relative winds. The present work draws on this conceptual model to identify preferred ranges of low- (model surface level), middle- (500 mb), and upper-level (250-mb) storm-relative wind speeds for 131 supercells, from gridded Eta Model fields. The observations reveal that the 500-mb storm-relative wind speed has a distinct lower bound of approximately 8 m s(-1) for the tornadic supercells, while differences between surface-level and 250-mb storm-relative wind speeds for tornadic and nontornadic supercells are much less pronounced. The storm-relative wind speeds are also compared to the bulk Richardson number shear for the purpose of discriminating between tornadic and nontornadic supercells. Test results of storm-relative wind speed al the Eta Model surface level and at 500 mb, derived from gridded Eta forecast fields, demonstrate skill in distinguishing tornadic and nontornadic supercells in daily forecast operations at the Storm Prediction Center. C1 NWS, NOAA, Storm Predict Ctr, Norman, OK 73069 USA. RP Thompson, RL (reprint author), NWS, NOAA, Storm Predict Ctr, 1313 Halley Circle, Norman, OK 73069 USA. EM richard.thompson@noaa.gov NR 45 TC 38 Z9 39 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1998 VL 13 IS 1 BP 125 EP 137 DI 10.1175/1520-0434(1998)013<0125:EMSRWA>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF645 UT WOS:000072917800008 ER PT J AU Snook, JS Stamus, PA Edwards, J Christidis, Z McGinley, JA AF Snook, JS Stamus, PA Edwards, J Christidis, Z McGinley, JA TI Local-domain mesoscale analysis and forecast model support for the 1996 Centennial Olympic Games SO WEATHER AND FORECASTING LA English DT Article ID OPERATIONAL USE; SYSTEM; LAPS; RAMS AB The National Weather Service (NWS) developed the Olympic Weather Support System (OWSS) to provide specialized operational weather support for the 1996 Centennial Olympic Games in Atlanta. Operational implementation of the National Oceanic and Atmospheric Administration Forecast Systems Laboratory's Local Analysis and Prediction System (LAPS) was a key element of the OWSS. LAPS is a complete, three-dimensional data assimilation system that produced subhourly atmospheric analyses on an 8-km grid covering all the Olympic venues. The LAPS analyses also provided initial conditions to the Regional Atmospheric Modeling System (RAMS) mesoscale forecast model. RAMS forecasts were generated at least every 3 h using 8- or 2-km grids. For the first time, a comprehensive operational analysis and forecast system operated iii a local NWS forecast office to support meso-beta-scale forecasts and warnings. Numerous benefits of LAPS-RAMS to the local forecast office were demonstrated. The OWSS, with LAPS-RAMS included, provided a precursory view of the enhanced operational mesoscale forecast capabilities that can be available to the NWS and other forecast offices in the near future. C1 NOAA, Forecast Syst Lab, Boulder, CO 80303 USA. IBM Corp, Yorktown Heights, NY USA. Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. RP Snook, JS (reprint author), NOAA, Forecast Syst Lab, Boulder, CO 80303 USA. NR 35 TC 28 Z9 32 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1998 VL 13 IS 1 BP 138 EP 150 DI 10.1175/1520-0434(1998)013<0138:LDMAAF>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF645 UT WOS:000072917800009 ER PT J AU Marzban, C Stumpf, GJ AF Marzban, C Stumpf, GJ TI A neural network for damaging wind prediction SO WEATHER AND FORECASTING LA English DT Article ID FORECAST VERIFICATION; DIAGNOSTIC VERIFICATION AB A neural network is developed to diagnose which circulations detected by the National Severe Storms Laboratory's Mesocyclone Detection Algorithm yield damaging wind. In particular, 23 variables characterizing the circulations are selected to be used as the input nodes of a feed-forward, supervised neural network. The outputs of the network represent the existence/nonexistence of damaging wind, based on ground observations. A set of 14 scalar, nonprobabilistic measures and a set of two multidimensional, probabilistic measures are employed to assess the performance of the network. The former set includes measures of accuracy, association, discrimination, skill, and the latter consists of reliability and refinement diagrams. Two classification schemes are also examined. It is found that a neural network with two hidden nodes outperforms a neural network with no hidden nodes when performance is gauged with any of the 14 scalar measures, except for a measure of discrimination where the results are opposite. The two classification schemes perform comparably to one another. As for the performance of the network in terms of reliability diagrams, it is shown that the process by which the outputs are converted to probabilities allows for the forecasts to be completely reliable. Refinement diagrams complete the representation of the calibration-refinement factorization of the joint distribution of forecasts and observations. C1 Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale & Meteorol Studies, Norman, OK 73019 USA. Univ Oklahoma, Dept Phys, Norman, OK 73019 USA. RP Marzban, C (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. EM marzban@gump.nssl.noaa.gov NR 25 TC 27 Z9 27 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1998 VL 13 IS 1 BP 151 EP 163 DI 10.1175/1520-0434(1998)013<0151:ANNFDW>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF645 UT WOS:000072917800010 ER PT J AU Velden, CS Olander, TL Zehr, RM AF Velden, CS Olander, TL Zehr, RM TI Development of an objective scheme to estimate tropical cyclone intensity from digital geostationary satellite infrared imagery SO WEATHER AND FORECASTING LA English DT Article AB The standard method for estimating the intensity of tropical cyclones is based on satellite observations (Dvorak technique) and is utilized operationally by tropical analysis centers around the world. The technique relies on image pattern recognition along with analyst interpretation of empirically based rules regarding the vigor and organization of convection surrounding the storm center. While this method performs well enough in most cases to be employed operationally, there are situations when analyst judgment can lead to discrepancies between different analysis centers estimating the same storm. In an attempt to eliminate this subjectivity, a computer-based algorithm that operates objectively on digital infrared information has been developed. An original version of this algorithm (engineered primarily by the third author) has been significantly modified and advanced to include selected "Dvorak rules," additional constraints, and a time-averaging scheme. This modified version, the Objective Dvorak Technique (ODT), is applicable to tropical cyclones that have attained tropical storm or hurricane strength. The performance of the ODT is evaluated on cases from the 1995 and 1996 Atlantic hurricane seasons. Reconnaissance aircraft measurements of minimum surface pressure are used to validate the satellite-based estimates. Statistical analysis indicates the technique to be competitive with, and in some cases superior to, the Dvorak-based intensity estimates produced operationally by satellite analysts from tropical analysis centers. Further analysis reveals situations where the algorithm needs improvement, and directions for future research and modifications are suggested. C1 Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI 53706 USA. NOAA, Reg & Mesoscale Meteorol Branch, NESDIS, Ft Collins, CO USA. RP Velden, CS (reprint author), Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, 1225 W Dayton St, Madison, WI 53706 USA. NR 6 TC 73 Z9 81 U1 0 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1998 VL 13 IS 1 BP 172 EP 186 DI 10.1175/1520-0434(1998)013<0172:DOAOST>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF645 UT WOS:000072917800012 ER PT J AU Doswell, CA Brooks, HE AF Doswell, CA Brooks, HE TI Budget cutting and the value of weather services SO WEATHER AND FORECASTING LA English DT Editorial Material ID FORECAST VERIFICATION AB The authors discuss the relationship between budget-cutting exercises and knowledge of the value of weather services. The complex interaction between quality (accuracy) and value of weather forecasts prevents theoretical approaches from contributing much to the discussion, except perhaps to indicate some of the sources for its complexity. The absence of comprehensive theoretical answers indicates the importance of empirical determinations of forecast value; as it stands, the United States is poorly equipped to make intelligent decisions in the current and future budget situations. To obtain credible empirical answers, forecasters will need to develop closer working relationships with their users than ever before, seeking specific information regarding economic value of forecasts. Some suggestions for developing plausible value estimates are offered, based largely on limited studies already in the literature. Efforts to create closer ties between forecasters and users can yield diverse benefits, including the desired credible estimates of the value of forecasts, as well as estimates of the sensitivity of that value to changes in accuracy of the forecasts. The authors argue for the development of an infrastructure to make these empirical value estimates, as a critical need within weather forecasting agencies, public and private, in view of continuing budget pressures. C1 NOAA, ERL, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Doswell, CA (reprint author), NOAA, ERL, Natl Severe Storms Lab, Norman, OK 73069 USA. RI Doswell III, Charles/E-7662-2010 NR 15 TC 13 Z9 13 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1998 VL 13 IS 1 BP 206 EP 212 DI 10.1175/1520-0434(1998)013<0206:BCATVO>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF645 UT WOS:000072917800014 ER PT J AU Farahani, M Antonucci, JM Karam, LR AF Farahani, M Antonucci, JM Karam, LR TI A GC-MS study of the addition reaction of aryl amines with acrylic monomers SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article AB Previous studies have shown that the interaction of carboxylic acid groups with the amine functionalities of aryl amines, especially secondary and tertiary aryl amines, can lead to the free-radical polymerization of acrylic monomers such as methyl methacrylate. In this study, the Michael addition reaction of primary and secondary aryl amines with acrylic monomers such as acrylic acid (AA) was investigated. Equivalent amounts of either p-toluidine (PT) or N-phenylglycine (NPG) and AA were combined in polar solvents such as ethanol. The reactions were conducted at ambient (23 degrees C) or near-ambient (37-60 degrees C) temperatures. Samples (about 3-5 mg) of these products were then trimethylsilylated with a solution consisting of 0.4 mt of bis (trimethylsilyl) trifluoroacetamide (BSTFA) and 0.4 mt of acetonitrile by heating for 30 min at 140 degrees C under N-2. These derivatives were characterized by gas chromatography-mass spectrometry (CC-MS). The CC-MS analyses suggest that 1 mol of the primary amine PT had reacted with 2 mol of AA to yield the expected N-p-tolyliminodipropionic acid. Similarly, the secondary amine NPC added to 1 mol of AA. yielded the corresponding mixed iminodiacid, N-phenyliminoacetic-propionic acid. It would appear that the Michael reaction of primary and secondary amines with acrylic monomers may offer a general, facile synthetic route to a variety of tertiary amines. Aryl amino acids of the type synthesized in this study may find use in a number of dental applications, e.g., as surface-active adhesive agents and as polymerization initiators or activators. (C) 1998 John Wiley & Sons, Inc. C1 NIST, Paffenbarger Res Ctr, ADAHF, Gaithersburg, MD 20899 USA. NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. RP Farahani, M (reprint author), NIST, Paffenbarger Res Ctr, ADAHF, Gaithersburg, MD 20899 USA. NR 5 TC 14 Z9 14 U1 0 U2 6 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD FEB 28 PY 1998 VL 67 IS 9 BP 1545 EP 1551 DI 10.1002/(SICI)1097-4628(19980228)67:9<1545::AID-APP6>3.0.CO;2-D PG 7 WC Polymer Science SC Polymer Science GA YU963 UT WOS:000071774200006 ER PT J AU Roads, JO Chen, SC Kanamitsu, M Juang, H AF Roads, JO Chen, SC Kanamitsu, M Juang, H TI Vertical structure of humidity and temperature budget residuals over the Mississippi River basin SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UNITED-STATES; NASA/DAO REANALYSES; NCEP/NCAR; PRECIPITATION; FORECASTS; IMPACT; SYSTEM AB Analyses have systematic tendencies or budget residuals that are not small. Unlike the budgets in general circulation model simulations, these budget residuals are an important component of analyses' water and energy budgets. We can either get good budgets or good climates, but not both. To better understand the character of the residuals in the National Centers for Environmental Prediction's (NCEP) global analysis and reanalysis water and energy budgets, the vertical structure of the budget residuals in NCEP's global analyses pertinent to the Mississippi River basin water and energy budgets are described herein. The vertical structure of the residuals is obtained by using NCEP's reanalysis modeling system, which is initialized (started) from NCEP's operational Global Data Assimilation System analyses as well as from the new NCEP reanalyses;forecasts of 1 day duration, 4 times a day, are then made for several years. The budget residuals in the forecasts after the first 6 hours are similar to the original residuals in the analyses and reanalyses. The residuals appear to be related to a summertime "spin-down" and wintertime "spin-up" in cumulus convection, an adjustment in boundary layer diffusive transports near the surface and near the top of the boundary layer, and adjustments in large-scale transports of moisture and temperature. These residuals may thus be providing clues as to what needs to be improved in analysis systems. C1 Univ Calif San Diego, Scripps Inst Oceanog, Div Climate Res, La Jolla, CA 92093 USA. Natl Ctr Environm Predict, Climate Predict Ctr, Camp Springs, MD 20746 USA. Natl Ctr Environm Predict, Environm Modeling Ctr, Camp Springs, MD USA. RP Roads, JO (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Div Climate Res, 9500 Gilman Dr, La Jolla, CA 92093 USA. EM jroads@ucsd.edu; schen@ucsd.edu NR 26 TC 26 Z9 29 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 27 PY 1998 VL 103 IS D4 BP 3741 EP 3759 DI 10.1029/97JD02759 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ481 UT WOS:000072258400001 ER PT J AU Solomon, S Portmann, RW Sanders, RW Daniel, JS AF Solomon, S Portmann, RW Sanders, RW Daniel, JS TI Absorption of solar radiation by water vapor, oxygen, and related collision pairs in the Earth's atmosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID VISIBLE SPECTROSCOPY; MCMURDO-STATION; TEMPERATURE-DEPENDENCE; NITROGEN-DIOXIDE; CLOUDS; ANTARCTICA; SPECTRA; MODELS; LIGHT; (O2)2 AB Absorption of solar radiation by collision pairs of oxygen is a small but significant part of the total budget of incoming shortwave radiation. It is shown that the 1.26-mu m band of O-4 and O-2 . N-2 is likely to contribute 0.64-1.55 W m(-2) to the total atmospheric absorption for overhead Sun, clear sky conditions, bringing the total estimated absorption by all collision pairs of oxygen over all wavelengths from 300- to 1300-nm to 2.2-3.11 W m(-2) for overhead Sun under clear sky. The globally averaged all-sky absorption by collision complexes of oxygen is likely to be about 0.9-1.3 W m(-2), roughly twice the value of previous estimates neglecting the 1.26-mu m band and the contribution of O-2 . N-2. Significant uncertainties are shown to remain in the spectroscopy of O-4 and O-2 . N-2 in the near-infrared band at 1.26-mu m (and possibly also at 1.06-mu m), requiring modern laboratory measurements to better quantify these processes. Atmospheric measurements are also presented in this paper to verify the spectral shape of the absorption by O-4 and other trace gases (O-2, H2O, NO2, and O-3) in the 610- to 680-nm and 400- to 450-nm regions. These observations rule out the existence of significant unknown "anomalous" or unexplained absorbers displaying structured features under either clear or cloudy conditions at these wavelengths. However, the possibility of anomalous broad continuum or quasi-continuum absorption cannot be evaluated using our measurement technique. The observed wavelength dependence of water vapor absorption in the bands near 442- and 650-nm are shown to agree well with their expected spectral structure under both clear and cloudy sky conditions for the instrumental resolution employed. Further, both the shape and magnitude of the measured atmospheric O-4 absorption near 630-nm agree with expectations based on recent laboratory measurements of this band to better than 10% over a broad range of zenith angles. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Solomon, S (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. EM solomon@al.noaa.gov RI Portmann, Robert/C-4903-2009; Daniel, John/D-9324-2011 OI Portmann, Robert/0000-0002-0279-6087; NR 52 TC 67 Z9 67 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 27 PY 1998 VL 103 IS D4 BP 3847 EP 3858 DI 10.1029/97JD03285 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ481 UT WOS:000072258400009 ER PT J AU Lin, B Minnis, P Wielicki, B Doelling, DR Palikonda, R Young, DF Uttal, T AF Lin, B Minnis, P Wielicki, B Doelling, DR Palikonda, R Young, DF Uttal, T TI Estimation of water cloud properties from satellite microwave, infrared and visible measurements in oceanic environments 2. Results SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOLAR-RADIATION MEASUREMENTS; EFFECTIVE PARTICLE RADIUS; UPPER-AIR OBSERVATIONS; LIQUID WATER; MARINE STRATOCUMULUS; OPTICAL-THICKNESS; PARAMETERIZATION; SURFACE; CLIMATE; PATH AB yA microwave (MW) method for deriving cloud liquid water path (LWP) and cloud water temperature (Tw) is validated by using soundings and results from a visible (VIS) and infrared (IR) retrieval method. The two retrieval methods are combined into a single technique, MVI (microwave, visible, and infrared), to estimate the frequency of multilayered clouds and the effective droplet radius re in water clouds. These techniques were applied to Meteosat and special sensor microwave/imager (SSM/I) data taken during June 1-28, 1992, over the Atlantic Stratocumulus Transition Experiment (ASTEX) region. For low clouds, as identified with the VIS-IR method, Tw on avenge is nearly the same as the VIS-IR cloud-top temperatures (Tc). A negative correlation between LWP and Tc was found for the clouds. For midlevel clouds, Tw is about 8 K warmer than Tc because of either large cloud thicknesses or multilayered clouds. When high clouds are found by the VIS-IR method, Tc is similar to 30 K colder than Tw, indicating that lower-level liquid-water clouds may be detected by the MW method. On the basis of the matched Tw and Tc obsevations, the estimated frequencies of multilayered high, middle, and low clouds are about 36%, 19%, and 0%, respectively, values that are similar to cloud radar measurements. Matched satellite and ground-based radar data show that the MVI technique can separate cloud layers when high ice clouds overlap lower liquid water clouds. The distributions of re for water clouds are about the same for low, middle, and broken clouds with mean and standard deviations of similar to 12 and 10 mu m, respectively. The frequency of large droplets (r(e) > 16 mu m) suggests that drizzle occurs in similar to 30% of the matched Meteosat-SSM/I cloudy conditions. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Analyt Serv & Mat Inc, Hampton, VA 23681 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Lin, B (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. EM bing@front.larc.nasa.gov; doelling@elviso.larc.nasa.gov RI Minnis, Patrick/G-1902-2010 OI Minnis, Patrick/0000-0002-4733-6148 NR 42 TC 32 Z9 33 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 27 PY 1998 VL 103 IS D4 BP 3887 EP 3905 DI 10.1029/97JD02817 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ481 UT WOS:000072258400013 ER PT J AU Coyle, ST Scheinfein, MR Blue, JL AF Coyle, ST Scheinfein, MR Blue, JL TI Defect induced lowering of activation energies at step bands in Co/Cu(100) SO APPLIED PHYSICS LETTERS LA English DT Article ID SURFACES; FILMS; MICROSCOPY AB Complex topological features such as rectangular voids and step inclusions that were seen in secondary electron micrographs of Co films grown on Cu(100) at room temperature were reproduced in Monte Carlo simulations in the presence of step bands. Lowered activation energies at defects such as steps, kinks, and vacancies enhance step edge restructuring during growth and upon annealing, This results in features such as faceted step edges, rectangular pits, incorporation of Co into terraces, surface alloying, and surface segregation. Simulated growth structures are directly compared with those observed in an ultrahigh vacuum scanning transmission electron microscope. (C) 1998 American Institute of Physics. C1 Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Coyle, ST (reprint author), Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. EM Michael.Scheinfein@asu.edu NR 14 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD FEB 23 PY 1998 VL 72 IS 8 BP 912 EP 914 DI 10.1063/1.120871 PG 3 WC Physics, Applied SC Physics GA ZJ463 UT WOS:000073218200014 ER PT J AU Fehsenfeld, FC Huey, LG Sueper, DT Norton, RB Williams, EJ Eisele, FL Mauldin, RL Tanner, DJ AF Fehsenfeld, FC Huey, LG Sueper, DT Norton, RB Williams, EJ Eisele, FL Mauldin, RL Tanner, DJ TI Ground-based intercomparison of nitric acid measurement techniques SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OBSERVATORY PHOTOCHEMISTRY EXPERIMENT; HNO3/NOX RATIO; RURAL SITE; TROPOSPHERE; MLOPEX-2; AEROSOL; NITRATE; FILTER; AIR; NOX AB An informal intercomparison of gas-phase nitric acid (HNO3) measuring techniques was carried out. The intercomparison involved two new chemical ionization mass spectrometers (CIMSs) that have been developed for the measurement of HNO3 along with an older, more established filter pack (FP) technique. The filter pack was composed of a teflon prefilter which collected aerosols followed by a nylon filter which collected the gas-phase HNO3. The study was carried out during the late winter and early spring of 1996 at a site located on the western edge of the Denver metropolitan area, Throughout the study the two CIMS techniques were in general agreement, However, under certain conditions the HNO3 levels obtained from the nylon filter of the FP gave values for the gas-phase concentration of HNO3 that were somewhat higher than that recorded by the two CIMS systems. The formation of ammonium nitrate (NH4NO3) containing aerosols is common during the colder months in this area. An analysis of these results suggests that the HNO3 collected by the nylon filter in the FP suffers an interference associated with the disproportionation of NH4NO3 from aerosols containing that compound that were initially collected on the teflon prefilter, This problem with the FP technique has been suggested from results obtained in previous intercomparisons. C1 NOAA, Aeron Lab, Environm Res Labs, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. RP Fehsenfeld, FC (reprint author), NOAA, Aeron Lab, Environm Res Labs, Mail Stop R-E-AL7,325 Broadway, Boulder, CO 80303 USA. RI Williams, Eric/F-1184-2010; Fehsenfeld, Frederick/I-4876-2013 NR 24 TC 31 Z9 32 U1 2 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1998 VL 103 IS D3 BP 3343 EP 3353 DI 10.1029/97JD02213 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YY455 UT WOS:000072148300001 ER PT J AU Huey, LG Dunlea, EJ Lovejoy, ER Hanson, DR Norton, RB Fehsenfeld, FC Howard, CJ AF Huey, LG Dunlea, EJ Lovejoy, ER Hanson, DR Norton, RB Fehsenfeld, FC Howard, CJ TI Fast time response measurements of HNO3 in air with a chemical ionization mass spectrometer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERIC TRACE GASES; NITRIC-ACID; ION CHEMISTRY; STRATOSPHERE; TROPOSPHERE; SITE AB A chemical ionization mass spectrometer has been developed for fast time response measurements of HNO3 in ambient air. The apparatus was characterized in an informal intercomparison campaign at Green Mountain Mesa in Boulder, Colorado. Nitric acid was measured over a wide range of meteorological conditions. Detection limits of less than 15 pptv for a 1 s integration period were routinely obtained. The apparatus was sufficiently sensitive to measure ambient levels of HNO3 for all conditions except for periods of fog or heavy precipitation when HNO3 mixing ratios were less than 10 pptv. C1 NOAA, Aeron Lab, Environm Res Labs, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Huey, LG (reprint author), NOAA, Aeron Lab, Environm Res Labs, Mail Stop R-E-AL7,325 Broadway, Boulder, CO 80303 USA. EM ghuey@pima.al.noaa.gov RI Fehsenfeld, Frederick/I-4876-2013 NR 15 TC 62 Z9 62 U1 2 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1998 VL 103 IS D3 BP 3355 EP 3360 DI 10.1029/97JD02214 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YY455 UT WOS:000072148300002 ER PT J AU Hood, LL Zhou, S AF Hood, LL Zhou, S TI Stratospheric effects of 27-day solar ultraviolet variations: An analysis of UARS MLS ozone and temperature data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RESEARCH SATELLITE UARS; MIDDLE ATMOSPHERE; NIMBUS-7 SAMS; LONG-TERM; IRRADIANCE; RESPONSES; INSTRUMENT; SBUV; VARIABILITY; BEHAVIOR AB The characteristics of upper stratospheric ozone and temperature responses at low latitudes to short-term solar ultraviolet variations are studied by using 1000 days of UARS microwave limb sounder (MLS) and solar stellar irradiance comparison experiment data. Consistent with previous analyses of Nimbus 7 solar backscattered ultraviolet (SBUV) data, the high-pass-filtered solar flux in the 200-to 205-nm interval is most strongly correlated with MLS ozone measurements at tropical latitudes near 4 hPa with a sensitivity of about 0.4% for each 1% change in the solar flux. Reproducibility tests, power spectral, and coherency estimates support the reality of the observed ozone response at this level. The MLS solar UV/ozone response is significantly reduced at levels above similar to 2 hPa as compared to earlier results based on SBUV data. This reduction appears to be a consequence of the ozone diurnal cycle at high altitudes combined with the necessary inclusion of nighttime records in calculating the MLS ozone zonal averages. Some evidence is obtained for an MLS solar UV/temperature response near the stratopause, but coherency tests are negative. Future analyses of independent data records having similar local time coverage as that of Nimbus 7 SBUV are needed to establish more definitively whether any significant change in the upper stratospheric UV response has occurred. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. NOAA, Natl Ctr Environm Predict, Washington, DC USA. RP Hood, LL (reprint author), Univ Arizona, Lunar & Planetary Lab, 1629 E Univ Blvd, Tucson, AZ 85721 USA. EM lon@lpl.arizona.edu NR 35 TC 21 Z9 21 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1998 VL 103 IS D3 BP 3629 EP 3638 DI 10.1029/97JD02849 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YY455 UT WOS:000072148300023 ER PT J AU Harwood, MH Burkholder, JB Ravishankara, AR AF Harwood, MH Burkholder, JB Ravishankara, AR TI Photodissociation of BrONO2 and N2O5: Quantum yields for NO3 production at 248, 308, and 352.5 nm SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID VISIBLE ABSORPTION-SPECTRA; PHOTOLYSIS; KINETICS; O(3P); BR-2 AB Quantum yields for NO3 production ill the photolysis of BrONO2 and N2O5 were measured at 248, 308, and 352.5 nm. The measured values for BrONO2 were found to be independent of pressure over the range 150-600 Torr and bath gas (N-2 or O-2) and are 0.28 +/- 0.09, 1.01 +/- 0.35, and 0.92 +/- 0.43 at 248, 308, and 352.5 nm, respectively. Quantum yields of Br and BrO in the photolysis of BrONO2 were also estimated. The measured values for NO3 production in the photolysis of N2O5 were 0.64 +/- 0.10, 0.96 +/- 0.15, and 1.03 +/- 0.15 at 248, 308, and 352.5 nm, respectively. Rate coefficients for the reactions Br + BrONO2 --> Br-2 + NO3 (18) and Cl + BrONO2 --> ClBr + NO3 (19) were measured at 298 K to be k(18) = (6.7 +/- 0.7) x 10(-11) cm(3) molecule(-1) s(-1) and k(19) = (1.27 +/- 0.16) x 10(-10) cm(3) molecule(-1) s(-1). The NO3 product yields for reactions 18 and 19 were measured to be 0.88 +/- 0.08 and 1.04 +/- 0.24, respectively. The absorption cross sections for N2O5 between 208 and 398 nm are also reported. All quoted uncertainties are 2 sigma and include estimated systematic errors, On the basis of the measured quantum yields of NO3, the atmospheric photolysis rate of BrONO2 is discussed. C1 NOAA, Environm Res Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Burkholder, JB (reprint author), NOAA, Environm Res Lab, R-E-AL2,325 Broadway, Boulder, CO 80303 USA. RI Burkholder, James/H-4914-2013; Ravishankara, Akkihebbal/A-2914-2011 NR 23 TC 30 Z9 31 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 FEB 19 PY 1998 VL 102 IS 8 BP 1309 EP 1317 DI 10.1021/jp9729829 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YY566 UT WOS:000072161000011 ER PT J AU Bryant, GW AF Bryant, GW TI Probing quantum nanostructures with near-field optical microscopy and vice versa SO APPLIED PHYSICS LETTERS LA English DT Article ID SPECTROSCOPY; WIRE; DOTS AB A theory for using near-held optical microscopy to probe quantum nanostructures is presented. Optical transition rates are determined for dots excited by the near field of a tip. Local-held corrections are neglected. Results for different tip/dot configurations and sizes show that near-field excitation can enhance light-hole transitions, excite selection-rule breaking transitions with rates comparable to allowed transitions, and map electron-hole pair wave functions. Conversely, dot response can be used to characterize tip near fields. C1 NIST, Gaithersburg, MD 20899 USA. RP Bryant, GW (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 16 TC 40 Z9 40 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD FEB 16 PY 1998 VL 72 IS 7 BP 768 EP 770 DI 10.1063/1.120868 PG 3 WC Physics, Applied SC Physics GA ZH583 UT WOS:000073126000006 ER PT J AU Mombru, AW Prassides, K Christides, C Erwin, R Pissas, M Mitros, C Niarchos, D AF Mombru, AW Prassides, K Christides, C Erwin, R Pissas, M Mitros, C Niarchos, D TI Neutron powder diffraction study (T=4.2-300 K) and polarization analysis of YBaCuFeO5+delta SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID OXYGEN-DEFICIENT PEROVSKITE; MAGNETIC-STRUCTURE; MOSSBAUER AB The crystal and magnetic structures of the perovskite YBaCuFeO5+delta have been studied in the temperature range T = 4.2-300 K by powder neutron diffraction. In addition to the antiferromagnetic ordering transition at T-N = 442 K, a commensurate-incommensurate magnetic transition is detected at T'(N) = 190 K. Below this temperature, two sets of satellite peaks surround the (1/2, 1/2, 1/2) magnetic peak at d similar to 5.15 Angstrom, collapsing into a single set of satellites below 155 K. Polarization analysis has been performed to confirm the magnetic nature of the (1/2, 1/2, 1/2)(+/-) satellites. C1 Fac Quim, Lab Cristallog, Catedra Fis, Montevideo 11800, Uruguay. Univ Sussex, Sch Chem Phys & Environm Sci, Brighton BN1 9QJ, E Sussex, England. NCSR Demokritos, Inst Mat Sci, Athens 15310, Greece. Natl Inst Stand & Technol, Div Reactor Radiat, Gaithersburg, MD 20899 USA. RP Mombru, AW (reprint author), Fac Quim, Lab Cristallog, Catedra Fis, POB 1157, Montevideo 11800, Uruguay. RI Prassides, Kosmas/C-9804-2009 NR 12 TC 31 Z9 32 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD FEB 16 PY 1998 VL 10 IS 6 BP 1247 EP 1258 DI 10.1088/0953-8984/10/6/008 PG 12 WC Physics, Condensed Matter SC Physics GA YY022 UT WOS:000072104000008 ER PT J AU Ramakrishnan, V Pradip Malghan, SG AF Ramakrishnan, V Pradip Malghan, SG TI The stability of alumina-zirconia suspensions SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article; Proceedings Paper CT Engineering-Foundation Conference on Particle Science and Technology in the 21st Century CY DEC 17-21, 1995 CL TATA RES DEV DESIGN CTR, PUNE, INDIA SP Engn Fdn, USA, Dept Sci & Technol, India, Int Fine Particle Res Inst, UK, Engn Res Ctr Particle Sci Technol, Univ Florida, Tata Steel, Hindustan Zinc Ltd, Assoc Cements Co Ltd, Goodlass Nerolac Paints Ltd HO TATA RES DEV DESIGN CTR DE stability; alumina; zirconia; concentrated suspension; viscosity; yield stress ID HETEROCOAGULATION; COMPOSITES AB Mixed suspensions exhibit heterocoagulation and therefore their pH range of stability is different from that of single powder suspensions. The effect of electrical double layer forces on the stability of single and mixed suspensions of alumina and zirconia was experimentally assessed by settling studies on dilute suspensions and rheological studies on concentrated suspensions. The stability of single and mixed suspensions was modelled in terms of the stability ratio (W) and the predicted pH range of stability were found to be in reasonable agreement with the experimental data. The behaviour of concentrated suspensions (up to 30 vol.%) was similar to that of 0.1 wt.% dilute suspensions. (C) 1998 Elsevier Science B.V. C1 Tata Res Dev & Design Ctr, Pune 411013, Maharashtra, India. NIST, Gaithersburg, MD 20899 USA. RP Pradip (reprint author), Tata Res Dev & Design Ctr, 54 B Hadapsar Ind Estate, Pune 411013, Maharashtra, India. NR 17 TC 12 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD FEB 15 PY 1998 VL 133 IS 1-2 BP 135 EP 142 DI 10.1016/S0927-7757(97)00135-0 PG 8 WC Chemistry, Physical SC Chemistry GA ZG535 UT WOS:000073013400018 ER PT J AU Santhiya, D Nandini, G Subramanian, S Natarajan, KA Malghan, SG AF Santhiya, D Nandini, G Subramanian, S Natarajan, KA Malghan, SG TI Effect of polymer molecular weight on the adsorption of polyacrylic acid at the alumina-water interface SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article; Proceedings Paper CT Engineering-Foundation Conference on Particle Science and Technology in the 21st Century CY DEC 17-21, 1995 CL TATA RES DEV DESIGN CTR, PUNE, INDIA SP Engn Fdn, USA, Dept Sci & Technol, India, Int Fine Particle Res Inst, UK, Engn Res Ctr Particle Sci Technol, Univ Florida, Tata Steel, Hindustan Zinc Ltd, Assoc Cements Co Ltd, Goodlass Nerolac Paints Ltd HO TATA RES DEV DESIGN CTR DE adsorption; alpha-alumina; electrokinetic; electrostatic and chemical interaction; hydrogen bonding; polyacrylic acid (PAA) ID POLYELECTROLYTES; COMPOSITES; MICROSTRUCTURE; STABILIZATION; FLOCCULATION; DISPERSANTS; SUSPENSIONS; PACKING; IONS AB The adsorption and electrokinetic characteristics of alumina suspensions in the presence of polyacrylic acid as a dispersant have been studied. The adsorption isotherms exhibit high-affinity Langmuirian behaviour. The adsorption density decreases with increasing in pH, while it increases with increasing molecular weight of the polymer. Electrokinetic studies indicate specific adsorption at and above the isoelectric point of the alumina sample. Possible mechanisms of interaction between alumina and polyacrylic acid are discussed. (C) 1998 Elsevier Science B.V. C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. Indian Inst Sci, Dept Met, Bangalore 560012, Karnataka, India. RP Malghan, SG (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. NR 36 TC 53 Z9 54 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD FEB 15 PY 1998 VL 133 IS 1-2 BP 157 EP 163 DI 10.1016/S0927-7757(97)00132-5 PG 7 WC Chemistry, Physical SC Chemistry GA ZG535 UT WOS:000073013400021 ER PT J AU Sivakumar, S Pradip Kapur, PC Malghan, SG AF Sivakumar, S Pradip Kapur, PC Malghan, SG TI A size interval-by-size interval marching algorithm for modelling grain growth in the intermediate stage of sintering SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article; Proceedings Paper CT Engineering-Foundation Conference on Particle Science and Technology in the 21st Century CY DEC 17-21, 1995 CL TATA RES DEV DESIGN CTR, PUNE, INDIA SP Engn Fdn, USA, Dept Sci & Technol, India, Int Fine Particle Res Inst, UK, Engn Res Ctr Particle Sci Technol, Univ Florida, Tata Steel, Hindustan Zinc Ltd, Assoc Cements Co Ltd, Goodlass Nerolac Paints Ltd HO TATA RES DEV DESIGN CTR DE grain growth; grain size distribution; modelling; simulation; sintering AB An accurate and efficient numerical algorithm is presented for solving the grain population balance equation which describes the evolution of micro-structure as a function of time in solid-state sintering. The solution scheme is based on the postulate that in a class of physically realistic deterministic systems, the queue or the relative order of particles in size is maintained intact as they grow and/or decay in time. The resulting size interval-by-size interval marching algorithm has been validated with the available asymptotic steady-state analytical solutions of grain growth/ripening model equations. It can be employed to simulate the sintering process in a more quantitative and realistic manner than what has been possible hitherto, especially in the intermediate stage of sintering, which is of practical interest in ceramic systems. A variety of simulations showing the effects of initial grain size distribution and sintering time are presented. Potential applications for optimizing the sintering process are discussed. (C) 1998 Elsevier Science B.V. C1 Tata Res Dev & Design Ctr, Pune 411013, Maharashtra, India. NIST, Gaithersburg, MD 20899 USA. RP Pradip (reprint author), Tata Res Dev & Design Ctr, 54 B,Hadapsar Ind Estate, Pune 411013, Maharashtra, India. NR 19 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD FEB 15 PY 1998 VL 133 IS 1-2 BP 173 EP 182 DI 10.1016/S0927-7757(97)00136-2 PG 10 WC Chemistry, Physical SC Chemistry GA ZG535 UT WOS:000073013400023 ER PT J AU Szuszczewicz, EP Blanchard, P Wilkinson, P Crowley, G Fuller-Rowell, T Richards, P Abdu, M Bullett, T Hanbaba, R Lebreton, JP Lester, M Lockwood, M Millward, G Wild, M Pulinets, S Reddy, BM Stanislawska, I Vannaroni, G Zolesi, B AF Szuszczewicz, EP Blanchard, P Wilkinson, P Crowley, G Fuller-Rowell, T Richards, P Abdu, M Bullett, T Hanbaba, R Lebreton, JP Lester, M Lockwood, M Millward, G Wild, M Pulinets, S Reddy, BM Stanislawska, I Vannaroni, G Zolesi, B TI The first real-time worldwide ionospheric predictions network: An advance in support of spaceborne experimentation, on-line model validation, and space weather SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MISSION; TSS-1 AB We report on the first realtime ionospheric predictions network and its capabilities to ingest a global database and forecast F-layer characteristics and "in situ" electron densities along the track of an orbiting spacecraft. A global network of ionosonde stations reported around-the-clock observations of F-region heights and densities, and an on-line library of models provided forecasting capabilities. Each model was tested against the incoming data; relative accuracies were intercompared to determine the best overall fit to the prevailing conditions; and the best-fit model was used to predict ionospheric conditions on an orbit-to-orbit basis for the 12-hour period following a twice-daily model test and validation procedure. It was found that the best-fit model often provided averaged (i.e., climatologically-based) accuracies better than 5% in predicting the heights and critical frequencies of the F-region peaks in the latitudinal domain of the TSS-1R flight path. There was a sharp contrast however, in model-measurement comparisons involving predictions of actual, unaveraged, along-track densities at the 295 km orbital altitude of TSS-1R In this case, extrema in the first-principle models varied by as much as an order of magnitude in density predictions, and the best-fit models were found to disagree with the "in situ" observations of Ne by as much as 140%. The discrepancies are interpreted as a manifestation of difficulties in accurately and self-consistently modeling the external controls of solar and magnetospheric inputs and the spatial and temporal variabilities in electric fields, thermospheric winds, plasmaspheric fluxes, and chemistry. C1 Sci Applicat Int Corp, Mclean, VA 22102 USA. Inst Nacl Pesquisas Espaciais, Sao Paulo, Brazil. Phillips Lab, Hanscom AFB, MA USA. SW Res Inst, San Antonio, TX USA. NOAA, Boulder, CO USA. France Telecom, CNET, Lannion, France. European Space Agcy, Estec, Dept Space Sci, NL-2200 AG Noordwijk, Netherlands. Univ Leicester, Leicester, Leics, England. Rutherford Appleton Lab, Didcot, Oxon, England. Natl Geophys Res Inst, Hyderabad 500007, Andhra Pradesh, India. Univ Alabama, Huntsville, AL 35899 USA. Polish Acad Sci, Space Res Ctr, PL-01237 Warsaw, Poland. CNR, Ist Fis Spazio Interplanetario, I-00044 Frascati, Italy. IPS Radio & Space Serv, W Chatswood, Australia. RP Szuszczewicz, EP (reprint author), Sci Applicat Int Corp, 1710 Goodridge Dr,POB 1303, Mclean, VA 22102 USA. RI Lockwood, Mike/G-1030-2011; Pulinets, Sergey/F-7462-2011 OI Lockwood, Mike/0000-0002-7397-2172; Pulinets, Sergey/0000-0003-3944-6686 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 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 15 PY 1998 VL 25 IS 4 BP 449 EP 452 DI 10.1029/97GL03279 PG 4 WC Geosciences, Multidisciplinary SC Geology GA YY192 UT WOS:000072122500011 ER PT J AU Hintsa, EJ Newman, PA Jonsson, HH Webster, CR May, RD Herman, RL Lait, LR Schoeberl, MR Elkins, JW Wamsley, PR Dutton, GS Bui, TP Kohn, DW Anderson, JG AF Hintsa, EJ Newman, PA Jonsson, HH Webster, CR May, RD Herman, RL Lait, LR Schoeberl, MR Elkins, JW Wamsley, PR Dutton, GS Bui, TP Kohn, DW Anderson, JG TI Dehydration and denitrification in the Arctic polar vortex during the 1995-1996 winter SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LOWER STRATOSPHERE; CONDENSATION NUCLEI; HYDROGEN BUDGET; NASA ER-2; AIRCRAFT; CLOUD; PARTICLES; NITROGEN; AEROSOL; HNO3 AB Dehydration of more than 0.5 ppmv water was observed between 18 and 19 km (theta similar to 450-465 K) at the edge of the Arctic polar vortex on February 1, 1996. More than half the reactive nitrogen (NO,) had also been removed, with layers of enhanced NO, at lower altitudes. Back trajectory calculations show that air parcels sampled inside the vortex had experienced temperatures as low as 188 K within the previous 12 days, consistent with a small amount of dehydration. The depth of the dehydrated layer (similar to 1 km) and the fact that trajectories passed through the region of ice saturation in one day imply selective growth of a small fraction of particles to sizes large enough (>10 mu m) to be irreversibly removed on this timescale. Over 25% of the Arctic vortex in a 20-30 K range of theta is estimated to have been dehydrated in this event. C1 Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Postgrad Sch, Dept Meteorol, Monterey, CA 94943 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80307 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hintsa, EJ (reprint author), Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. RI Newman, Paul/D-6208-2012; Herman, Robert/H-9389-2012 OI Newman, Paul/0000-0003-1139-2508; Herman, Robert/0000-0001-7063-6424 NR 19 TC 31 Z9 31 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 15 PY 1998 VL 25 IS 4 BP 501 EP 504 DI 10.1029/98GL00115 PG 4 WC Geosciences, Multidisciplinary SC Geology GA YY192 UT WOS:000072122500024 ER PT J AU McInnes, L Bergin, M Ogren, J Schwartz, S AF McInnes, L Bergin, M Ogren, J Schwartz, S TI Apportionment of light scattering and hygroscopic growth to aerosol composition SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTHROPOGENIC AEROSOLS; OPTICAL-PROPERTIES; HUMIDITY; CLIMATE; SIZE AB During a recent campaign at the NOAA CMDL monitoring station on Sable Island, Canada (43.93 degrees N, 60.01 degrees W) a dual-nephelometer humidigraph measured the hygroscopic growth factor of aerosol scattering, f(RH)(sigma(sp)), one of the key parameters necessary for estimating short-wave aerosol radiative forcing. Measurements revealed less growth anthropogenically influenced aerosols than for marine, f(RH)(sigma(sp)) of 1.7 +/- 0.1 vs. 2.7 +/- 0.4, where f(RH)(sigma(sp)) = sigma(sp(85%))/sigma(sp(40%)). combined measurement-modeling approach was used to estimate sigma(sp) and its RH-dependence, based on the measured particle size distribution and composition. The model suggested that differences in the particle size distribution, assuming the same aerosol composition, could not explain the observed differences in f(RH)(sigma(sp)). We have confirmed with individual particle analysis, that aerosol composition was indeed responsible for the difference in f(RH)(sigma(sp)). As well, the scattering contribution of organic carbon for the influenced case is at least as much as sulfate aerosol. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Brookhaven Natl Lab, Environm Chem Div, Upton, NY 11973 USA. RP McInnes, L (reprint author), NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RI Schwartz, Stephen/C-2729-2008; Ogren, John/M-8255-2015 OI Schwartz, Stephen/0000-0001-6288-310X; Ogren, John/0000-0002-7895-9583 NR 16 TC 64 Z9 66 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 15 PY 1998 VL 25 IS 4 BP 513 EP 516 PG 4 WC Geosciences, Multidisciplinary SC Geology GA YY192 UT WOS:000072122500027 ER PT J AU Baker, EA Collette, BB AF Baker, EA Collette, BB TI Mackerel from the northern Indian Ocean and the Red Sea are Scomber australasicus, not Scomber japonicus SO ICHTHYOLOGICAL RESEARCH LA English DT Article DE Scomber australasicus; Scomber japonicus; mackerel; Indian Ocean AB The population of Scomber from the Red Sea and northern Indian Ocean (gulfs of Aden and Oman) is identified as S. australasicus rather than S. japonicus based on having 30-33 vs. 26-29 interneural bones under the first and second dorsal fins and the combination of interneural bone counts of 16-20 under the first dorsal fin (vs. 13-16) and first dorsal fin spine counts of 10-13 (vs. 9-10). These are the best morphological characters to distinguish these two species. This change in identification constitutes a major range extension for S. australasicus which was thought to be restricted to the Pacific Ocean and the southeastern Indian Ocean around Western Australia. C1 Univ Toronto, Toronto, ON, Canada. Natl Museum Nat Hist, Natl Marine Fisheries Serv, Systemat Lab, Washington, DC 20560 USA. RP Baker, EA (reprint author), Univ Toronto, 100 Coll St, Toronto, ON, Canada. NR 8 TC 7 Z9 8 U1 0 U2 0 PU ICHTHYOLOGICAL SOC JAPAN PI TOKYO PA BUSINESS CENTER ACADEMIC SOC JAPAN, 5-16-9 HONKOMAGOME, BUNKYO-KU, TOKYO, 113, JAPAN SN 1341-8998 J9 ICHTHYOL RES JI Ichthyol. Res. PD FEB 15 PY 1998 VL 45 IS 1 BP 29 EP 33 DI 10.1007/BF02678572 PG 5 WC Zoology SC Zoology GA ZC990 UT WOS:000072639700005 ER PT J AU Materer, N Goodman, RS Leone, SR AF Materer, N Goodman, RS Leone, SR TI Comparison of electron cyclotron resonance and radio-frequency inductively coupled plasmas of Ar and N-2: Neutral kinetic energies and source gas cracking SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; ATOMIC-NITROGEN-PRODUCTION; ION ENERGY; ZNSE-N; TEMPERATURES; GROWTH; DISTRIBUTIONS; FLUORESCENCE; DIAGNOSTICS; ARGON AB Neutral mean kinetic energies and the amount of neutral source gas cracking of particles emanating from an electron cyclotron resonance (ECR) plasma source and a radio-frequency inductively coupled plasma (ICP) source are compared as a function of applied power by modulated beam time-of-flight analysis for Ar and N-2 gases. For both sources, the source chamber is maintained at 0.07 Pa by a constant flow of either Ar or N-2, while the applied power is varied from 50 to 250 W and from 50 to 550 W for the ECR and the ICP sources, respectively. For the Ar plasmas, the neutral Ar mean kinetic energies are similar and range between 0.07 and 0.15 eV, with the ICP being somewhat higher. In the case of the N-2 plasmas, the ICP mean energies are also somewhat higher than those found for the ECR source. The mean energies range between 0.02 and 0.26 eV and 0.02 and 0.40 eV for the N-2 and N species, respectively. The N:N-2 flux ratio for the ICP source increases to a plateau of approximately 0.021 +/- 0.002 after an applied power of 250 W is reached, while for the ECR plasmas, the N:N-2 flux ratio varies in a more complex fashion with a much higher value of 0.17 +/- 0.04. (C) 1998 American Institute of Physics. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Biochem & Chem, Boulder, CO 80309 USA. RP Materer, N (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 29 TC 8 Z9 8 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD FEB 15 PY 1998 VL 83 IS 4 BP 1917 EP 1923 DI 10.1063/1.366916 PG 7 WC Physics, Applied SC Physics GA 108GG UT WOS:000075257300013 ER PT J AU Mountain, DG Taylor, MH AF Mountain, DG Taylor, MH TI Spatial coherence of interannual variability in water properties on the US northeast shelf SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID MAINE; GULF; SALINITY AB Interannual variability in the surface and bottom temperature and salinity on the U.S. northeast shelf is described by using hydrographic data from the Northeast Fisheries Science Center (NEFSC) MARMAP program. This 10 year data set provides the spatial resolution to describe spatial patterns in the variability of the shelf water properties. An empirical orthogonal function analysis is used to determine the primary modes df variability. All parameters investigated have significant first modes, which contain 40-50% of the variance in the winter and 25-35% in the summer period. All parameters, except the summer surface temperature, exhibit coherent variability across the entire shelf region from near Cape Hatteras to the central Gulf of Maine. The summer surface temperature appears to have two regions of coherent variability: in the central Middle Atlantic Eight and in the western Gulf of Maine. This regionalization is believed due to the effect of local sources of coastal runoff. C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Mountain, DG (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 23 TC 8 Z9 9 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 15 PY 1998 VL 103 IS C2 BP 3083 EP 3092 DI 10.1029/97JC03052 PG 10 WC Oceanography SC Oceanography GA YY122 UT WOS:000072115500020 ER PT J AU Walton, CC Sullivan, JT Rao, CRN Weinreb, MP AF Walton, CC Sullivan, JT Rao, CRN Weinreb, MP TI Corrections for detector nonlinearities and calibration inconsistencies of the infrared channels of the advanced very high resolution radiometer SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article AB The data received from the thermal infrared channel 4 (similar to 10.3-11.3 mu m) and channel 5 (similar to 11.5-12.5 mu m) of the advanced very high resolution radiometer (AVHRR) flown on the National Oceanic and Atmospheric Administration (NOAA) Polar-Orbiting Operational Environmental Satellites provide only a linear estimate of the actual radiance. We describe here a simple procedure, which incorporates data from prelaunch calibration tests,to correct the linear estimates for the nonlinear response of the channels 4 and 5 Mercury-Cadmium-Telluride (Hg-Cd-Te) sensors. The procedure applies a "nonzero radiance of space" concept to specify the form of the linear radiance estimate. This linear radiance is nearly independent of the operating temperature of the AVHRR and is the sole input to the correction algorithm. Additionally, it is demonstrated with NOAA 14 data that this calibration procedure resolves discrepancies found in the prelaunch data which can affect the calibration accuracy of channel 3 (similar to 3.55-3.95 mu m), which possesses a linear response, as well as channels 4 and 5. When applied to independent sets of prelaunch calibration data, this procedure reproduces the laboratory-measured temperature data to within an accuracy of 0.1 degrees-0.2 degrees K. Comparison with nonlinearity corrections based on different procedures points to the superior applicability of the present results over the entire range of Earth-scene temperatures measured by the AVHRR in orbit. This accuracy is particularly important when these three infrared channels are used in multichannel algorithms to generate environmental parameters such as sea surface temperature. The algorithm coefficients and values of the nonzero radiance of space required to calculate the nonlinearity radiance corrections are given for the. AVHRRs on NOAA 7, 9, 10, 11, 12, and 14 spacecraft. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Satellite Res Lab, Washington, DC 20233 USA. RP Walton, CC (reprint author), NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Satellite Res Lab, Washington, DC 20233 USA. NR 14 TC 41 Z9 42 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 15 PY 1998 VL 103 IS C2 BP 3323 EP 3337 DI 10.1029/97JC02018 PG 15 WC Oceanography SC Oceanography GA YY122 UT WOS:000072115500036 ER PT J AU Karen, P Kjekshus, A Huang, Q Lynn, JW Rosov, N Natali Sora, I Karen, VL Mighell, AD Santoro, A AF Karen, P Kjekshus, A Huang, Q Lynn, JW Rosov, N Natali Sora, I Karen, VL Mighell, AD Santoro, A TI Neutron and X-ray powder diffraction study of RBa2Fe3O8+w phases SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID MAGNETIC-PROPERTIES; 123 FAMILY; LNBA2FE3OZ; YBA2FE3O8; OXYGEN; CRYSTAL; SYSTEM AB Compounds of composition RBa2Fe3O8+w (R = La, Nd, Sm, Gd, Dy, Er, Yb, Lu, and Y) with variable oxygen content have been synthesized using the liquid mixing technique and have been analyzed by powder X-ray and neutron diffraction methods. A triple perovskite-type structure with ordered Ba and R cations and having the symmetry of space group P4/mmm was obtained only for R = Y, Dy, and Er, whereas the larger R atoms gave the atomic arrangement of disordered, defective perovskites with average symmetry Pm (3) over bar m. No perovskite-type phases were obtained when Yb and Lu were tried. The oxygen content of the oxygen-saturated phases was found to increase with increasing size of the cation R from w = 0.07 for Er to w = 0.83 for La. The Neel temperature (similar to 650 K) and the magnitude of the Fe magnetic moment (similar to 3.3 mu(B) at room temperature) are highest when trivalent iron is involved (w = 0), but these quantities are rather insensitive to the nature of R and to slight variations of oxygen content in the triple perovskite-type structure of the Y, Dy, and Er compounds. In the case of the cubic structures, however, both quantities depend strongly on the oxygen stoichiometry. In the magnetically ordered state, nearest-neighbor iron moments are coupled antiferromagnetically along the three crystallographic directions in all samples, resulting in magnetic structures with symmetry Imm'm and magnetic unit cells related to those of the corresponding nuclear structures by the transformation matrix(1 (1) over bar 0/110/002). (C) 1998 Academic Press. C1 Univ Oslo, Dept Chem, N-0315 Oslo, Norway. Univ Maryland, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Div Reactor Radiat, Gaithersburg, MD 20899 USA. RP Karen, P (reprint author), Univ Oslo, Dept Chem, POB 1033, N-0315 Oslo, Norway. RI Karen, Pavel/A-9062-2008; Natali Sora, Isabella/C-8357-2011 OI Karen, Pavel/0000-0003-2937-6477; NR 25 TC 16 Z9 16 U1 0 U2 13 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD FEB 15 PY 1998 VL 136 IS 1 BP 21 EP 33 DI 10.1006/jssc.1997.7636 PG 13 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA ZM936 UT WOS:000073591200004 ER PT J AU Zhou, ZX Carton, JA AF Zhou, ZX Carton, JA TI Latent heat flux and interannual variability of the coupled atmosphere-ocean system SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SEA-SURFACE TEMPERATURE; EVAPORATION-WIND FEEDBACK; TROPICAL PACIFIC; UNIFIED VIEW; MODEL; OSCILLATIONS; LIMIT AB This study examines the impact of the moisture exchange between the oceanic and atmospheric boundary layers on instabilities of the atmosphere-ocean system. Wind speed-sensitive evaporation can affect these instabilities in two ways. First, it can change atmospheric heating and thus modify the atmospheric wind response. Second, it can change the mixed layer heat budget and thus affect SST. Here the authors show that wind speed-sensitive evaporation produces a new unstable, westward-propagating SST mode with a growth rate of (4 month)(-1) for standard parameters. These two processes, alternatively, act to stabilize the leading unstable mixed SST-dynamics mode if each is considered separately. However, the strongest instability of this mixed SST-dynamics mode occurs when the first process is relatively weak and the second is strong. The authors extend the work to consider the impact of wind speed-sensitive evaporation on the intermediate coupled model of Zebiak and Cane. The results from this model are similar to those obtained in the free mode analysis. C1 Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. RP Zhou, ZX (reprint author), NOAA, AOML, PHOD, 4301 Rickenbacker Causeway, Miami, FL 33156 USA. RI carton, james/C-4807-2009 OI carton, james/0000-0003-0598-5198 NR 21 TC 13 Z9 16 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD FEB 15 PY 1998 VL 55 IS 4 BP 494 EP 501 DI 10.1175/1520-0469(1998)055<0494:LHFAIV>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ514 UT WOS:000072261700002 ER PT J AU Li, J Ramaswamy, V AF Li, J Ramaswamy, V TI Comments on "Four-stream spherical harmonic expansion approximation for solar radiative transfer" - Reply SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article C1 Univ Victoria, Canadian Ctr Climate, Atmospher Environm Serv, Victoria, BC V8P 2Y2, Canada. Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08544 USA. RP Li, J (reprint author), Univ Victoria, Canadian Ctr Climate, Atmospher Environm Serv, POB 1700, Victoria, BC V8P 2Y2, Canada. EM acrnrjl@ec.gc.ca RI Li, Jiangnan/J-6262-2016 NR 7 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD FEB 15 PY 1998 VL 55 IS 4 BP 673 EP 675 DI 10.1175/1520-0469(1998)055<0673:R>2.0.CO;2 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ514 UT WOS:000072261700014 ER PT J AU Jaskolski, W Bryant, GW AF Jaskolski, W Bryant, GW TI Multiband theory of quantum-dot quantum wells: Dim excitons, bright excitons, and charge separation in heteronanostructures SO PHYSICAL REVIEW B LA English DT Article ID CDS/HGS/CDS; PHOTOPHYSICS; COLLOIDS AB Electron, hole, and exciton states of multishell CdS/HgS/CdS quantum-dot quantum-well nanocrystals are determined by use of a multiband theory that includes valence-band mixing, modeled with a six-band Luttinger-Kohn Hamiltonian, and nonparabolicity of the conduction band. The multiband theory correctly describes the recently observed dim-exciton ground state and the lowest, optically active, bright-exciton states. Charge separation in pair states is identified. Previous single-band theories could not describe these states or account for charge separation. [S0163-1829(98)52108-X]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Inst Fiz UMK, Torun, Poland. RP Jaskolski, W (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM garnett.bryant@nist.gov RI Jaskolski, Wlodzimierz/D-1318-2014 OI Jaskolski, Wlodzimierz/0000-0003-4814-1876 NR 21 TC 34 Z9 35 U1 1 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 FEB 15 PY 1998 VL 57 IS 8 BP R4237 EP R4240 DI 10.1103/PhysRevB.57.R4237 PG 4 WC Physics, Condensed Matter SC Physics GA YZ177 UT WOS:000072228000012 ER PT J AU Ji, XH Braxenthaler, M Moult, J Fronticelli, C Bucci, E Gilliland, GL AF Ji, XH Braxenthaler, M Moult, J Fronticelli, C Bucci, E Gilliland, GL TI Conformation of the sebacyl beta(1)Lys82-beta(2)Lys82 crosslink in T-state human hemoglobin SO PROTEINS-STRUCTURE FUNCTION AND GENETICS LA English DT Article DE crosslinked hemoglobin; protein crystallography; T-state hemoglobin; macromolecular modeling, three-dimensional structure ID POLYPHOSPHATE-BINDING-SITE; GLUTATHIONE-S-TRANSFERASE; X-RAY-DIFFRACTION; 3-DIMENSIONAL STRUCTURE; HUMAN DEOXYHEMOGLOBIN; OXYGEN-BINDING; BETA-CHAINS; RESOLUTION; ACID; REFINEMENT AB The crystal structure of human T state hemoglobin crosslinked with bis(3,5-dibromo-salicyl) sebacate has been determined at 1.9 Angstrom resolution, The final crystallographic R factor is 0.168 with root-mean-square deviations (RMSD) from ideal bond distance of 0.018 Angstrom. The 10-carbon sebacyl residue found in the beta cleft covalently links the two beta Lys82 residues, The sebacyl residue assumes a zigzag conformation with cis amide bonds formed by the NZ atoms of beta Lys82's and the sebacyl carbonyl oxygens, The atoms of the crosslink have an occupancy factor of 1.0 with an average temperature factor for all atoms of 34 Angstrom(2), An RMSD of 0.27 for all CA's of the tetramer is observed when the crosslinked deoxyhemoglobin is compared with deoxyhemoglobin refined by using a similar protocol, 2HHD [Fronticelli et al, J. Biol. Chem. 269: 23965-23969, 1994], Thus, no significant perturbations in the tertiary or quaternary structure are introduced by the presence of the sebacyl residue, However, the sebacyl residue does displace seven water molecules in the beta cleft and the conformations of the beta(1)Lys82 and beta(2)Lys82 are altered because of the crosslinking, The carbonyl oxygen that is part of the amide bond formed with the NZ of beta(2)Lys82 forms a hydrogen bond with side chain of beta(2)Asn139 that is in turn hydrogen-bonded to the side chain of beta(2)Arg104, A comparison of the observed conformation with that modeled [Bucci et al, Biochemistry 35:3418-3425, 1996] shows significant differences, The differences in the structures can be rationalized in terms of compensating changes in the estimated free-energy balance, based on differences in exposed surface areas and the observed shift in the side-chain hydrogen-bonding pattern involving beta(2)Arg104, beta(2)Asn139, and the associated sebacyl carbonyl group. (C) 1998 Wiley-Liss, Inc. C1 Univ Maryland, Inst Biotechnol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Maryland, Sch Med, Dept Biol Chem, Baltimore, MD 21201 USA. Natl Inst Stand & Technol, Rockville, MD USA. RP Bucci, E (reprint author), Univ Maryland, Inst Biotechnol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. RI Ji, Xinhua/C-9664-2012 OI Ji, Xinhua/0000-0001-6942-1514 FU NHLBI NIH HHS [HLBI-48517] NR 45 TC 9 Z9 9 U1 0 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-3585 J9 PROTEINS JI Proteins PD FEB 15 PY 1998 VL 30 IS 3 BP 309 EP 320 DI 10.1002/(SICI)1097-0134(19980215)30:3<309::AID-PROT10>3.0.CO;2-J PG 12 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA ZA127 UT WOS:000072331600010 PM 9517546 ER PT J AU Rush, JJ AF Rush, JJ TI Multilab partnerships SO SCIENCE LA English DT Letter C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Rush, JJ (reprint author), NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 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 FEB 13 PY 1998 VL 279 IS 5353 BP 965 EP 965 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YX100 UT WOS:000072006400004 ER PT J AU Knutson, TR Tuleya, RE Kurihara, Y AF Knutson, TR Tuleya, RE Kurihara, Y TI Simulated increase of hurricane intensities in a CO2-warmed climate SO SCIENCE LA English DT Article ID TROPICAL CYCLONE CLIMATE; ANTHROPOGENIC CHANGES; MODELS AB Hurricanes can inflict catastrophic property damage and loss of human life. Thus, it is important to determine how the character of these powerful storms could change in response to greenhouse gas-induced global warming. The impact of climate warming on hurricane intensities was investigated with a regional, high-resolution, hurricane prediction model. In a case study, 51 western Pacific storm cases under present-day climate conditions were compared with 51 storm cases under high-CO2 conditions, More idealized experiments were also performed. The large-scale initial conditions were derived from a global climate model. For a sea surface temperature warming of about 2.2 degrees C, the simulations yielded hurricanes that were more intense by 3 to 7 meters per second (5 to 12 percent) for wind speed and 7 to 20 millibars for central surface pressure. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Knutson, TR (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 18 TC 157 Z9 174 U1 3 U2 24 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 FEB 13 PY 1998 VL 279 IS 5353 BP 1018 EP 1020 DI 10.1126/science.279.5353.1018 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YX100 UT WOS:000072006400043 ER PT J AU Hilton, GC Martinis, JM Wollman, DA Irwin, KD Dulcie, LL Gerber, D Gillevet, PM Twerenbold, D AF Hilton, GC Martinis, JM Wollman, DA Irwin, KD Dulcie, LL Gerber, D Gillevet, PM Twerenbold, D TI Impact energy measurement in time-of-flight mass spectrometry with cryogenic microcalorimeters SO NATURE LA English DT Article ID SUPERCONDUCTING TUNNEL JUNCTION; HOT-ELECTRON-MICROCALORIMETERS; DETECTORS AB Time-of-flight mass spectrometry-most notably matrix-assisted laser-desorption-ionization time-of-flight (MALDI-TOF) spectrometry(1)-is an important class of techniques for the study of proteins and other biomolecules(2). Although these techniques provide excellent performance for masses up to about 20,000 daltons, there has been Limited success in achieving good mass resolution at higher masses, This is because the sensitivity of the microchannel plate (MCP) detectors used in most systems decreases rapidly with increasing particle mass, limiting the utility of MCP detectors for very large masses, It has recently been proposed that cryogenic particle detectors may provide a solution to these difficulties(3). Cryogenic detectors measure the thermal energy deposited by the particle impact, and thus have a sensitivity that is largely independent of particle mass, Recent experiments(4-6) have demonstrated the sensitivity of cryogenic particle detectors to single biomolecules, a quantum efficiency several orders of magnitude larger than the MCP detectors, and sensitivity to masses as large as 750,000 daltons, Here we present results demonstrating an order of magnitude better energy resolution than previous measurements, allowing direct determination of particle charge state during acceleration(7). Although application of these detectors to practical mass spectrometry will require further development of the detectors and cryogenics, these detectors can be used to elucidate the performance-limiting processes that occur in such systems. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Univ Neuchatel, Inst Phys, CH-2000 Neuchatel, Switzerland. GenSpec SA, CH-2017 Boudry, Switzerland. George Mason Univ, Inst Biosci Bioinformat & Biotechnol, Manassas, VA 22210 USA. RP Hilton, GC (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. EM hilton@boulder.nist.gov NR 18 TC 97 Z9 98 U1 1 U2 15 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD FEB 12 PY 1998 VL 391 IS 6668 BP 672 EP 675 DI 10.1038/35582 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YW872 UT WOS:000071982500045 PM 9490410 ER PT J AU Karim, A Slawecki, TM Kumar, SK Douglas, JF Satija, SK Han, CC Russell, TP Liu, Y Overney, R Sokolov, O Rafailovich, MH AF Karim, A Slawecki, TM Kumar, SK Douglas, JF Satija, SK Han, CC Russell, TP Liu, Y Overney, R Sokolov, O Rafailovich, MH TI Phase-separation-induced surface patterns in thin polymer blend films SO MACROMOLECULES LA English DT Article ID ION MASS-SPECTROMETRY; SPINODAL DECOMPOSITION; POLYVINYL METHYL-ETHER); DIBLOCK COPOLYMERS; POLYSTYRENE; SEGREGATION; KINETICS; MIXTURE AB Atomic force microscopy (AFM), neutron reflection (NR) and secondary ion mass spectroscopy (SIMS) are used to examine phase separation in symmetrically segregating thin polymer blend films (less than or equal to 1000 Angstrom). Phase separation in the film leads to undulations of the liquid-air interface, provided the film is sufficiently thin to suppress surface-directed spinodal decomposition waves. Flattened droplets are formed at a very late stage of phase separation, and the aspect ratio of these droplets can be rationalized by an interfacial free energy minimization argument. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Univ Massachusetts, Dept Polymer Sci & Engn, Amherst, MA 01003 USA. SUNY Stony Brook, Dept Mat Sci, Stony Brook, NY 11790 USA. Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA. RP Karim, A (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 38 TC 159 Z9 161 U1 3 U2 45 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD FEB 10 PY 1998 VL 31 IS 3 BP 857 EP 862 DI 10.1021/ma970687g PG 6 WC Polymer Science SC Polymer Science GA YX025 UT WOS:000071998800041 ER PT J AU Duxbury, G McDonald, BD Van Gogh, M Alijah, A Jungen, C Palivan, H AF Duxbury, G McDonald, BD Van Gogh, M Alijah, A Jungen, C Palivan, H TI The effects of vibrational resonances on Renner-Teller coupling in triatomic molecules: The stretch-bender approach SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ORBITAL ANGULAR-MOMENTUM; AMPLITUDE BENDING VIBRATION; VARIATIONAL METHOD; VIBRONIC LEVELS; ENERGY-LEVELS; RIGID BENDER; 1A1 STATE; CH2; SPECTROSCOPY; SPECTRUM AB A vibration-rotation Hamiltonian for a symmetric triatomic molecule, based upon a stretch-bender reference frame has been derived. This frame is chosen so that as the molecule bends the reference geometry follows the minimum in the potential energy surface, thus minimizing the size of the displacements required to reach the instantaneous axis geometry. This may be regarded as an extension of methods based upon the rigid-bender reference frame approach developed by Hougen, Bunker, and Johns [J. Mel. Spectrosc. 34, 136 (1970)]. This new stretch-bender Hamiltonian is combined with the Barrow, Dixon, and Duxbury [Mel. Phys. 27, 1217 (1974)] and the Jungen and Merer [Mel. Phys. 40, 25 (1980)] methods of solving the Renner-Teller coupling problem in which molecules execute large amplitude nuclear motion, producing a compact method for the variational calculation of the energies of such a system. The (a) over tilde (1)A(1) and (b) over tilde B-1(1) states of the methylene radical, CH2, are used to demonstrate the use of this method for the analysis of the behavior of strongly coupled electronic and vibrational states. (C) 1998 American Institute of Physics. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Strathclyde, Dept Phys & Appl Phys, Glasgow G4 0NG, Lanark, Scotland. Univ Bielefeld, Fak Chem, D-33501 Bielefeld, Germany. Univ Paris Sud, Aime Cotton Lab, CNRS, F-91405 Orsay, France. RP Duxbury, G (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. RI Alijah, Alexander/A-4079-2013 OI Alijah, Alexander/0000-0002-4915-0558 NR 40 TC 36 Z9 36 U1 2 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 8 PY 1998 VL 108 IS 6 BP 2336 EP 2350 DI 10.1063/1.475619 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YV251 UT WOS:000071804500011 ER PT J AU Duxbury, G Alijah, A McDonald, BD Jungen, C AF Duxbury, G Alijah, A McDonald, BD Jungen, C TI Stretch-bender calculations of the effects of orbital angular momentum and vibrational resonances in the spectrum of singlet methylene SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MAGNETIC-ROTATION SPECTROSCOPY; RENNER-TELLER; TRIATOMIC-MOLECULES; VISIBLE ABSORPTION; 1A1 STATE; CH2; (CH2)-C-1 AB The stretch-bender Hamiltonian for a symmetric triatomic molecule, which we have recently derived for a symmetric triatomic molecule [Duxbury et al., J. Chem. Phys. 108, 2336 (1998), preceding paper], has been used in conjunction with the Barrow, Dixon, and Duxbury [Mol. Phys. 27, 1217 (1974)] and the Jungen and Merer [Mel. Phys. 40, 25 (1980)] methods of solving the Renner-Teller coupling problem in molecules which are executing large amplitude nuclear motion, to calculate the vibronic structure of the (a) over tilde (1)A(1) and (b) over tilde B-1(1) states of the methylene radical CH2. The results of the compact stretch-bender variational calculations are compared with the more extensive calculations of Green et al. [J. Chem. Phys. 94, 118 (1991)] to show that good agreement between the two methods has been demonstrated. We have also compared the relative and complementary uses of following the variation of the calculated expectation value of the orbital angular momentum, [L-z], and of the "end over end" rotation constants B and q, as increasingly complex vibronic mixing is caused by the interplay between Renner-Teller and anharmonic coupling. In the present example the anharmonic coupling is principally due to Fermi resonance terms. (C) 1998 American Institute of Physics. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Bielefeld, Fak Chem, D-33501 Bielefeld, Germany. Univ Strathclyde, Dept Phys & Appl Phys, Glasgow G4 0NG, Lanark, Scotland. Univ Paris Sud, Aime Cotton Lab, CNRS, F-91405 Orsay, France. RP Duxbury, G (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. RI Alijah, Alexander/A-4079-2013 OI Alijah, Alexander/0000-0002-4915-0558 NR 21 TC 31 Z9 31 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 8 PY 1998 VL 108 IS 6 BP 2351 EP 2360 DI 10.1063/1.475620 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YV251 UT WOS:000071804500012 ER PT J AU Hobbie, EK Holter, MJ AF Hobbie, EK Holter, MJ TI Depletion-force kinetics in confined colloidal mixtures SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HARD-SPHERE FLUIDS; PHASE-SEPARATION; FRACTAL AGGREGATION; DYNAMICS AB Depletion-force kinetics in confined nearly hard-sphere mixtures are interpreted within the context of reversible two-dimensional aggregation. The cluster-size distribution function of the minority component exhibits an exponential decay in the cluster size, with a time-dependent decay constant that relaxes toward the steady-state value suggested by simulations of two-dimensional evaporation-condensation phenomena with Brownian (random-walk) trajectories. This similarity is attributed to a greatly reduced mobility of the aggregates with respect to unbound large spheres. (C) 1998 American Institute of Physics. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. Specialty Coating Syst, Clear Lake, WI 54005 USA. RP Hobbie, EK (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. EM erik.hobbie@nist.gov RI Hobbie, Erik/C-8269-2013 NR 26 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 8 PY 1998 VL 108 IS 6 BP 2618 EP 2621 DI 10.1063/1.475647 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YV251 UT WOS:000071804500042 ER PT J AU Guldi, DM Neta, P Heger, A Vogel, E Sessler, JL AF Guldi, DM Neta, P Heger, A Vogel, E Sessler, JL TI Octaethylcorrphycene and its metal complexes. Radiolytic reduction studies SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ONE-ELECTRON OXIDATION; PI-RADICAL ANIONS; PORPHYRIN ISOMER; 2-ELECTRON REDUCTION; NICKEL PORPHYRINS; REDOX PROPERTIES; AQUEOUS-SOLUTION; METHYL RADICALS; PORPHIN ISOMER; PORPHYCENES AB One-electron and multielectron reductions of 2,3,6,7,11,12,17,18-octaethylcorrphycene (H(2)OECn) and its sn(IV), Fe(III), Co(II), Ni(II), Cu(II), and Ag(II) complexes in 2-propanol (2-PrOH) solutions have been studied by radiolytic techniques. Formation and decay of unstable intermediates formed upon one-electron reduction have been followed by kinetic spectrophotometric pulse radiolysis. The absorption spectra of stable reduction products have been recorded following gamma-radiolysis, H(2)OECn is reduced to a transient pi-radical anion, (H(2)OECn)(.-), which decays by disproportionation to form a product with a chlorin-like spectral signature. Sn(IV)OECn is reduced io a stable pi-radical anion and subsequently to the dianion, which protonates to a species that, on the basis of its spectral characterization, Is considered to be a phlorin-anion-type product, Fe(III), Co(III), Co(II), and Ag(II) corrphycenes undergo radiolytic reduction at the metal center. The Fe(II) and Co(I) corrphycenes produced are stable, and upon farther reduction in neutral solutions they yield species with chlorin-like spectral signatures. When similar reductions are carried out in alkaline solutions, species with phlorin-anion-like characteristics are produced. Ag(I)OECn, due to its large ionic radius, undergoes demetalation. Cu(II)OECn is reduced al the ligand in neutral 2-PrOH, but in alkaline solutions it forms an unstable Cu(I)OECn complex, which disproportionates and demetalates. In contrast, reduction of Ni(II)OECn yields the pi-radical anion in acidic, neutral, and alkaline 2-PrOH solutions. These results suggest that the larger size of the corrphycene core, as compared with that of porphycenes, results in greater stability of complexes with metal ions of and larger radii. Ni(ll), Co(II), and Fe(II) corrphycenes also react rapidly with (CH3)-C-. radicals to form sigma-bonded CH3-M(III)OECn complexes, Whereas the CH3-Ni(III)OECn complex decays within <1 ms, the CH3-Fe(III)OECn complex proved stable in the absence of oxygen, and the corresponding CH3-Co(III)OECn species was found to be stable even in the presence of O-2. C1 Univ Notre Dame, Radiat Lab, Notre Dame, IN 46556 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Univ Cologne, Inst Organ Chem, D-50939 Cologne, Germany. Univ Texas, Dept Chem & Biochem, Austin, TX 78712 USA. RP Guldi, DM (reprint author), Univ Notre Dame, Radiat Lab, Notre Dame, IN 46556 USA. RI Guldi, Dirk/G-1422-2015 NR 44 TC 7 Z9 7 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD FEB 5 PY 1998 VL 102 IS 6 BP 960 EP 967 DI 10.1021/jp973341g PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YW472 UT WOS:000071939100012 ER PT J AU Lagalante, AF Bruno, TJ AF Lagalante, AF Bruno, TJ TI Modeling the water-supercritical CO2 partition coefficients of organic solutes using a linear solvation energy relationship SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID CARBON-DIOXIDE; SOLVENT; PREDICTION; OCTANOL; CHROMATOGRAPHY; SOLUBILITY; PARAMETER; PHASE AB A linear solvation energy relationship (LSER) has been developed to predict the water-supercritical CO2 partition coefficients for a published collection of data. The independent variables in the model are empirically determined descriptors of the solute and solvent molecules. The LSER approach provides an average absolute relative deviation of 22% in the prediction of the water-supercritical CO2 partition coefficients for the six solutes considered. Results suggest that other types of equilibrium precesses in supercritical fluids may be modeled using a LSER approach. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Lagalante, AF (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway,MS 838-01, Boulder, CO 80303 USA. EM lagalant@boulder.nist.gov NR 17 TC 28 Z9 28 U1 2 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD FEB 5 PY 1998 VL 102 IS 6 BP 907 EP 909 DI 10.1021/jp973047o PG 3 WC Chemistry, Physical SC Chemistry GA YW473 UT WOS:000071939200001 ER PT J AU Trevino, SF Joubran, R Parris, N Berk, NF AF Trevino, SF Joubran, R Parris, N Berk, NF TI Structure of a triglyceride microemulsion: A small-angle neutron scattering study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID IN-OIL MICROEMULSION; BICONTINUOUS STRUCTURE; MODEL MICROEMULSIONS; NONIONIC SURFACTANT; VEGETABLE-OILS; WATER; SYSTEMS; MICELLAR AB The microscopic structure of a microemulsion of triolein oil, aqua (water-ethanol, 80/20 wt %), and polyoxyethylene (40) sorbitol hexaoleats has been studied with small-angle neutron scattering. Contrast variation (in the scattering of neutrons) is accomplished by the deuteration of the aqua and oil components of the system. Samples for which only the aqueous phase is deuterated reveal the geometry of the aqueous phase, and those in which only the oil is deuterated reveal the geometry of the oil phase. Finally, when both oil and aqua are contrast matched by deuteration, the surfactant geometry is measured. The aqueous-surfactant surface and the oil-surfactant surface are found to be of significantly different geometries. These two surfaces are described in detail for varying aqua concentration by the very successful leveled-wave model. The behavior of the leveled-wave model parameters produced by the aqua geometry, as a function of aqua concentration and temperature, correlates with a thermodynamic instability in the miscibility. Further, the spectrum of neutrons produced by the surfactant itself is different from the aqua and oil spectra. Although a detailed geometric description of the surfactant is not available for this component (no geometric model being applicable), the data are consistent with there being different geometries for the two bounding surfaces. A plausible correlation between the geometric behavior of the material and a miscibility gap is also detected. C1 USA, Res Lab, Polymer Res Branch, Aberdeen Proving Ground, MD 21005 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. USDA ARS, Eastern Reg Res Ctr, Philadelphia, PA 19118 USA. RP Trevino, SF (reprint author), USA, Res Lab, Polymer Res Branch, Aberdeen Proving Ground, MD 21005 USA. NR 29 TC 9 Z9 9 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD FEB 5 PY 1998 VL 102 IS 6 BP 953 EP 960 DI 10.1021/jp971459r PG 8 WC Chemistry, Physical SC Chemistry GA YW473 UT WOS:000071939200009 ER PT J AU Nevel, LV Taylor, PDP Ornemark, U Moody, JR Heumann, KG De Bievre, P AF Nevel, LV Taylor, PDP Ornemark, U Moody, JR Heumann, KG De Bievre, P TI The International Measurement Evaluation Programme (IMEP) IMEP-6: "Trace elements in water" SO ACCREDITATION AND QUALITY ASSURANCE LA English DT Article DE trace elements; water; intercomparison; comparability; traceability AB The sixth round of the International Measurement Evaluation Programme (IMEP) is presented, The programme offers reference values, established by primary methods of measurement, against which participating laboratories can evaluate their performance, The degree of comparability is thus established against the most objective references available at present, In IMEP-6;, reference values for total concentrations of 14 trace elements in a synthetic and a natural water were established mainly by isotope dilution mass spectrometry (IDMS). For the majority of the measurands, results traceable to the international system of units (SI) and having expanded uncertainties, U (k = 2), of 2% could be established, Measurements results from 165 field laboratories in 29 countries are evaluated and presented as descriptive (regional, national and intercontinental) pictures of the participants' self-declared degree of experience, status of accreditation, performance (including target values for uncertainty set by authorities) and instrumental methods used, The participants' use of certified reference materials and calibrants has been documented, and some comments on this matter are raised. The results and characteristics for IMEP-6 are compared with those of IMEP-3 (1991-1993) and discussed in view of the forthcoming IMEP-9 (1998). C1 Commiss European Communities, Joint Res Ctr, Inst Reference Mat & Measurements, B-2440 Geel, Belgium. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Mainz, D-55099 Mainz, Germany. RP Nevel, LV (reprint author), Commiss European Communities, Joint Res Ctr, Inst Reference Mat & Measurements, B-2440 Geel, Belgium. NR 19 TC 1 Z9 2 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 FEB PY 1998 VL 3 IS 2 BP 56 EP 68 PG 13 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA ZC055 UT WOS:000072535000004 ER PT J AU Ferruzzi, MG Sander, LC Rock, CL Schwartz, SJ AF Ferruzzi, MG Sander, LC Rock, CL Schwartz, SJ TI Carotenoid determination in biological microsamples using liquid chromatography with a coulometric electrochemical array detector SO ANALYTICAL BIOCHEMISTRY LA English DT Article DE carotenoids; electrochemical detection; liquid chromatography; biological extracts; C-30 column; geometric isomers ID BUCCAL MUCOSAL CELLS; BETA-CAROTENE; ALPHA-TOCOPHEROL; HUMAN-PLASMA; VITAMIN-A; RETINOIDS; CANCER; TISSUE; ISOMERIZATION; ISOMERS AB Numerous epidemiological studies have linked carotenoids to cancer preventive processes, thereby increasing interest in levels of these micronutrients in human tissue and serum. Conventional analyses of these biological tissues employ liquid chromatography (LC) with ultraviolet and visible absorbance (UV-VIS) detection. However, this type of carotenoid analysis does not provide adequate sensitivity for very small sample sizes, such as microscale biopsies, when only small quantities of tissue are available. Electrochemical detection (ECD) is a useful alternative to conventional UV-VIS detection methods for LC analysis of carotenoids in cases where high sensitivity is necessary. Both hydrocarbon (beta-carotene and alpha-carotene) and oxygenated carotenoids (lutein, zeaxanthin, and beta-cryptoxanthin) were detected at electrical potential settings between 220 and 520 mV. The generated electrochemical array data (hydrodynamic voltammograms) can be used to identify carotenoids as well as to differentiate between trans and cis configurations. Detection limits for beta-carotene by ECD were measured at 10 fmol representing approximately a 100- to 1000-fold increase over conventional LC-UV-VIS techniques. The developed methodology was applied successfully to microscale analysis of biological tissues. (C) 1998 Academic Press. C1 Ohio State Univ, Dept Food Sci & Technol, Columbus, OH 43210 USA. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Div Analyt Chem, Gaithersburg, MD 20899 USA. Univ Calif San Diego, Dept Family & Prevent Med, La Jolla, CA 92093 USA. RP Schwartz, SJ (reprint author), Ohio State Univ, Dept Food Sci & Technol, Columbus, OH 43210 USA. EM schwartz.177@osu.edu OI Schwartz, Steven/0000-0002-1427-5780 NR 31 TC 69 Z9 70 U1 0 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD FEB 1 PY 1998 VL 256 IS 1 BP 74 EP 81 DI 10.1006/abio.1997.2484 PG 8 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA YV740 UT WOS:000071858000010 PM 9466800 ER PT J AU Smith, BC Wikfors, GH AF Smith, BC Wikfors, GH TI An automated rearing chamber system for studies of shellfish feeding SO AQUACULTURAL ENGINEERING LA English DT Article DE shellfish; nutrition; aquaculture; automation ID GROWTH AB Producing large volumes of high quality microalgae to feed shellfish and other organisms is a limiting factor in the development of the aquaculture industry. Feeding regimes yielding the highest conversion efficiencies of algal feed to molluscan growth are required to maximize the return on algal-culture investments. In the past we have used 12 specialized, manually-controlled molluscan rearing chambers to study nutritional requirements and growth of oysters, clams, and scallops. A computer-controlled, solenoid-valve system was added to automate seawater flow, volume of microalgal food delivered, and feeding duration independently for each chamber. Labor was reduced from 7 h per week to 3 h, while adding flexibility. Each chamber represents a model for a programmed nursery system. Evidence that superior growth of bivalves can be achieved by feeding regimes made possible by this apparatus are provided by an experiment with juvenile bay scallops (Argopecten irradians). Published by Elsevier Science B.V. C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Milford Lab, Milford, CT 06460 USA. RP Smith, BC (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Milford Lab, 212 Rogers Ave, Milford, CT 06460 USA. NR 10 TC 13 Z9 13 U1 1 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0144-8609 J9 AQUACULT ENG JI Aquac. Eng. PD FEB PY 1998 VL 17 IS 1 BP 69 EP 77 DI 10.1016/S0144-8609(97)00015-0 PG 9 WC Agricultural Engineering; Fisheries SC Agriculture; Fisheries GA ZF452 UT WOS:000072898900007 ER PT J AU Storebakken, T Shearer, KD Roem, AJ AF Storebakken, T Shearer, KD Roem, AJ TI Availability of protein, phosphorus and other elements in fish meal, soy-protein concentrate and phytase-treated soy-protein-concentrate-based diets to Atlantic salmon, Salmo salar SO AQUACULTURE LA English DT Article; Proceedings Paper CT VII International Symposium on Nutrition and Feeding of Fish CY AUG 11-15, 1996 CL TEXAS A&M UNIV, COLLEGE STN, TEXAS HO TEXAS A&M UNIV DE element-phosphorus; protein; digestibility-retention-excretion; fish meal; soy-concentrate; phytic acid-phytase; Atlantic salmon (Salmo salar) ID TROUT ONCORHYNCHUS-MYKISS; AMINO-ACID-REQUIREMENTS; RAINBOW-TROUT; PHYTIC ACID; WHOLE-BODY; GASTROINTESTINAL-TRACT; MICROBIAL PHYTASE; SOYBEAN-MEAL; FEED-INTAKE; GROWTH AB An experiment with 0.1-kg Atlantic salmon in saltwater was conducted to evaluate soy-protein concentrate as a source of dietary protein and to determine if phytase treatment of soy concentrate affected the availability of protein and essential elements. Three diets were fed to triplicate groups of fish for 84 days: Diet 1 with 61% fish meal, Diet 2 with 50% soy concentrate and 16% fish meal, and Diet 3 with 50% phytase-treated soy concentrate, The soy concentrate contained 18 g phytic acid kg(-1), and no phytate remained after phytase treatment. Soy concentrate was equivalent to fish meal as a source of dietary protein for Atlantic salmon, and incubation with phytase resulted in improved protein digestibility, feed conversion, protein retention, and reduced metabolic N-excretion. Whole-body Ca, Mg, and Zn levels, apparent digestibility coefficients of the same elements, and retentions of P and Zn were lower in fish fed the untreated soy concentrate compared to the phytase treated soy. Whole-body concentrations of Ca, Sr and Zn were correlated to P independent of dietary treatment, but the ratios between P and the other elements were not constant. The faecal output of Na was high for both soy concentrate diets independent of phytase treatment. (C) 1998 Elsevier Science B.V. C1 AKVAFORSK, Inst Aquaculture Res AS, N-6600 Sunndalsora, Norway. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. Nutreco Aquaculture Res Ctr, N-4033 Forus, Norway. RP Storebakken, T (reprint author), AKVAFORSK, Inst Aquaculture Res AS, N-6600 Sunndalsora, Norway. RI storebakken, trond/E-8050-2011 OI storebakken, trond/0000-0002-4525-2098 NR 55 TC 172 Z9 193 U1 1 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD FEB 1 PY 1998 VL 161 IS 1-4 BP 365 EP 379 DI 10.1016/S0044-8486(97)00284-6 PG 15 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA ZW815 UT WOS:000074451100032 ER PT J AU Gawlicka, A Herold, MA Shearer, KD de la Noue, J Hung, SSO AF Gawlicka, A Herold, MA Shearer, KD de la Noue, J Hung, SSO TI Biochemical changes in white sturgeon (Acipenser transmontanus) larvae during ontogeny SO AQUACULTURE LA English DT Article C1 Univ Laval, GREREBA, Laval, PQ G1K 7P4, Canada. Univ Calif Davis, Dept Anim Sci, Davis, CA 95616 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Gawlicka, A (reprint author), Univ Laval, GREREBA, Laval, PQ G1K 7P4, Canada. NR 0 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD FEB 1 PY 1998 VL 161 IS 1-4 BP 515 EP 515 PG 1 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA ZW815 UT WOS:000074451100046 ER PT J AU Key, PB Fulton, MH Scott, GI Layman, SL Wirth, EF AF Key, PB Fulton, MH Scott, GI Layman, SL Wirth, EF TI Lethal and sublethal effects of malathion on three life stages of the grass shrimp, Palaemonetes pugio SO AQUATIC TOXICOLOGY LA English DT Article DE malathion; acetylcholinesterase; grass shrimp; pulse dose exposure; sublethal effects ID LARVAL DEVELOPMENT; ACETYLCHOLINESTERASE; INHIBITION; METABOLISM; TOXICITY AB The effects of malathion exposure on three life stages of the grass shrimp (Palaemonetes pugio) were evaluated. After 96-h exposures, malathion was most toxic to newly hatched larvae with an LC50 of 9.06 mu g l(-1) followed by an LC50 of 13.24 mu g l(-1) for 18-day-old larvae and an LC50 of 38.19 mu g l(-1) for adult shrimp. In a separate bioassay, to simulate field conditions, newly hatched larvae were exposed to malathion at 6 h day(-1) every 5 days al a salinity of 10 parts per thousand? until metamorphosis to postlarvae. After four pulse dose exposures, mortality was highest in the two highest concentrations, of 15.0 and 30.0 mu g l(-1). The number of instars to postlarvae was significantly lower in the highest concentration compared to control. The findings indicate that malathion may not directly affect growth in a measurable way but may alter natural metamorphic rhythms at the highest concentrations. Whole body acetylcholinesterase (AChE) activity was measured on Day 0 and Day 15 from the pulse exposure lest. AChE activities were not significantly different from controls. Other factors than just AChE inhibition may have contributed to malathion toxicity. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 US Natl Marine Fisheries Serv, Charleston Lab, Charleston, SC 29412 USA. RP Key, PB (reprint author), US Natl Marine Fisheries Serv, Charleston Lab, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 28 TC 36 Z9 37 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-445X J9 AQUAT TOXICOL JI Aquat. Toxicol. PD FEB PY 1998 VL 40 IS 4 BP 311 EP 322 DI 10.1016/S0166-445X(97)00068-4 PG 12 WC Marine & Freshwater Biology; Toxicology SC Marine & Freshwater Biology; Toxicology GA ZD547 UT WOS:000072697500001 ER PT J AU Aneja, VP Murthy, AB Battye, W Battye, R Benjey, WG AF Aneja, VP Murthy, AB Battye, W Battye, R Benjey, WG TI Analysis of ammonia and aerosol concentrations and deposition near the free troposphere at Mt. Mitchell, NC, USA SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT International Conference on Atmospheric Ammonia - Emissions, Deposition and Environmental Impacts CY OCT 02-04, 1995 CL CULHAM, ENGLAND DE ammonia; deposition; emissions; ambient monitoring; Mt. Mitchell; Smoky Mountains ID DRY DEPOSITION; NEW-YORK; FOREST; CHEMISTRY; EUROPE AB Measurements of airborne (gaseous and aerosol), cloud water, and precipitation concentrations of ammonia (NH3) and ammonium (NH4+) compounds were made at Mt. Mitchell State Park (Mt. Gibbs, similar to 2006 m MSL), North Carolina. Measurements were made from May to September during 1988 and 1989. An annular denuder system was used to determine gaseous NH3 and particulate NH4+ and nitrate (NO3-) compounds. Measurements of NH4+ in cloud and rain water samples were made during the same time period. Mean concentrations of gaseous NH3 were 0.62 mu g m(-3) for 1988 and 1.47 mu g m(-3) for 1989. Mean concentrations of fine particulate NH4+ were 1.24 mu g m(-3) for 1988 and 0.89 mu g m(-3) for 1989. The NH4+ concentrations in the cloud water were 214 and 147 mu eq l(-1) for the 1988 and 1989 field seasons, respectively. The concentrations of NH4+ in precipitation were quite low compared to cloud ionic values in both 1988 and 1989 at 14 and 15 mu eq l(-1), respectively. The estimated mean total deposition of NH4+ over the sampling period (5 months) of 1988 and 1989 was about 0.38 and 0.67 g N m(-2) season(-1), respectively. Cloud water interception contributed more nitrogen (similar to 70%) to the total deposition than combined wet (similar to 15%) and dry (similar to 15%) deposition. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. EC R Inc, Durham, NC 27707 USA. NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27711 USA. RP Aneja, VP (reprint author), N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Box 8208, Raleigh, NC 27695 USA. NR 27 TC 25 Z9 26 U1 1 U2 3 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 FEB PY 1998 VL 32 IS 3 BP 353 EP 358 DI 10.1016/S1352-2310(97)00236-7 PG 6 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZC933 UT WOS:000072633600014 ER PT J AU Forsyth, WR Gilson, MK Antosiewicz, J Jarem, OR Robertson, AD AF Forsyth, WR Gilson, MK Antosiewicz, J Jarem, OR Robertson, AD TI Experimentally testing computational models for ionization equilibria in turkey ovomucoid third domain. SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 Univ Iowa, Dept Biochem, Iowa City, IA 52242 USA. NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Warsaw, Dept Biophys, PL-02089 Warsaw, Poland. RI Antosiewicz, Jan/G-1308-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1998 VL 74 IS 2 BP A369 EP A369 PN 2 PG 1 WC Biophysics SC Biophysics GA ZL549 UT WOS:000073445402130 ER PT J AU Luo, N Ramadas, N Krauss, M Osman, R AF Luo, N Ramadas, N Krauss, M Osman, R TI Molecular dynamics and quantum chemical study of uracil-DNA glycosylase: Specific recognition and catalytic mechanism SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 CUNY Mt Sinai Sch Med, Dept Physiol & Biophys, New York, NY 10029 USA. NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1998 VL 74 IS 2 BP A285 EP A285 PN 2 PG 1 WC Biophysics SC Biophysics GA ZL549 UT WOS:000073445401652 ER PT J AU Worcester, D Hammouda, B AF Worcester, D Hammouda, B TI Hydrocarbon chain interdigitation by hydrostatic pressure in C16-C22 phosphatidylcholines. SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 Univ Missouri, Div Biol, Columbia, MO 65211 USA. NIST, Cold Neutron Res Facil, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1998 VL 74 IS 2 BP A28 EP A28 PN 2 PG 1 WC Biophysics SC Biophysics GA ZL549 UT WOS:000073445400148 ER PT J AU Moran, P Dightman, DA Park, LK AF Moran, P Dightman, DA Park, LK TI Nonelectrophoretic genotyping using allele-specific PCR and a dsDNA-specific dye SO BIOTECHNIQUES LA English DT Article ID DNA-POLYMERASE C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Moran, P (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 9 TC 9 Z9 9 U1 0 U2 0 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 USA SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD FEB PY 1998 VL 24 IS 2 BP 206 EP + PG 4 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YW209 UT WOS:000071909400007 PM 9494715 ER PT J AU Grachev, AA Fairall, CW Larsen, SE AF Grachev, AA Fairall, CW Larsen, SE TI On the determination of the neutral drag coefficient in the convective boundary layer SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE convective boundary layer; drag coefficient; roughness length ID SURFACE-LAYER; ISOTROPIC TURBULENCE; WIND STRESS; SEA; HEAT; VELOCITY; FLUXES; TEMPERATURE; DEPENDENCE; ROUGHNESS AB Based on the idea that free convection can be considered as a particular case of forced convection, where the gusts driven by the large-scale eddies are scaled with the Deardorff convective velocity scale, a new formulation for the neutral drag coefficient, C-Dn, in the convective boundary layer (CBL) is derived. It is shown that (i) a concept of C-Dn can still be used under strongly unstable conditions including a pure free-convection regime even when no logarithmic portion in the velocity profile exists; (ii) gustiness corrections must be applied for rational calculations of C-Dn; and (iii) the stratification Psi function used in the derivation of C-Dn should satisfy the theoretical free-convection limit. The new formulation is compared with the traditional relationship for C-Dn, and data collected over the sea (during the Tropical Ocean-Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) and the San Clemente Ocean Probing Experiment (SCOPE)) and over land (during the BOREX-95 experiment) are used to illustrate the difference between the new and traditional formulations. Compared to the new approach, the traditional formulation strongly overestimates C-Dn and z(o) in the CBL for mean wind speed less than about 2 m s(-1). The new approach also clarifies several contradictory results from earlier works. Some aspects related to an alternate definition of the neutral drag coefficient and the wind speed and the stress averaging procedure are considered. C1 Russian Acad Sci, AM Obukhov Inst Atmospher Phys, Moscow 109017, Russia. NOAA, Environm Res Labs, Environm Technol Lab, Boulder, CO 80303 USA. Riso Natl Lab, Wind Energy & Atmospher Phys Dept, DK-4000 Roskilde, Denmark. RP Grachev, AA (reprint author), Russian Acad Sci, AM Obukhov Inst Atmospher Phys, Pyzhevsky Pereulok 3, Moscow 109017, Russia. OI GRACHEV, ANDREY/0000-0002-7143-0820 NR 44 TC 26 Z9 27 U1 1 U2 4 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 FEB PY 1998 VL 86 IS 2 BP 257 EP 278 DI 10.1023/A:1000617300732 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZC667 UT WOS:000072604500003 ER PT J AU Randall, D Curry, J Battisti, D Flato, G Grumbine, R Hakkinen, S Martinson, D Preller, R Walsh, J Weatherly, J AF Randall, D Curry, J Battisti, D Flato, G Grumbine, R Hakkinen, S Martinson, D Preller, R Walsh, J Weatherly, J TI Status of and outlook for large-scale modeling of atmosphere-ice-ocean interactions in the Arctic SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SHALLOW-WATER EQUATIONS; GLOBAL CLIMATE MODEL; GRAVITY-WAVE DRAG; SEA-ICE; THICKNESS DISTRIBUTION; GENERAL-CIRCULATION; NUMERICAL-INTEGRATION; STRATUS CLOUDS; SENSITIVITY; RADIATION AB Arctic air masses have direct impacts on the weather and climatic extremes of midlatitude areas such as central North America. Arctic physical processes pose special and very important problems for global atmospheric models used for climate simulation and numerical weather prediction. At present, the observational database is inadequate to support research aimed at overcoming these problems. Three interdependent Arctic field programs now being planned will help to remedy this situation: SHEBA, which will operate an ice camp in the Arctic for a year; ARM, which will supply instruments for use at the SHEBA ice camp and which will also conduct longer-term measurements near Barrow, Alaska; and FIRE, which will conduct one or more aircraft campaigns, in conjunction with remote-sensing investigations focused on the SHEBA ice camp. This paper provides an introductory overview of the physics of the Arctic from the perspective of large-scale modelers, outlines some of the modeling problems that arise in attempting to simulate these processes, and explains how the data to be provided by the three field programs can be used to test and improve large-scale models. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Univ Colorado, Boulder, CO 80309 USA. Univ Washington, Seattle, WA 98195 USA. Canadian Ctr Climate Modelling & Anal, Victoria, BC, Canada. Natl Ctr Environm Predict, Camp Springs, MD USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lamont Doherty Geophys Observ, Palisades, NY USA. USN, Res Lab, Stennis Space Ctr, MS 39529 USA. Univ Illinois, Urbana, IL 61801 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Randall, D (reprint author), Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RI Grumbine, Robert/B-9865-2008; Hakkinen, Sirpa/E-1461-2012; Battisti, David /A-3340-2013; Flato, Gregory/K-6711-2015; Randall, David/E-6113-2011 OI Battisti, David /0000-0003-4871-1293; Randall, David/0000-0001-6935-4112 NR 111 TC 110 Z9 115 U1 0 U2 10 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 FEB PY 1998 VL 79 IS 2 BP 197 EP 219 DI 10.1175/1520-0477(1998)079<0197:SOAOFL>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ883 UT WOS:000072303900001 ER PT J AU Karl, TR Knight, RW AF Karl, TR Knight, RW TI Secular trends of precipitation amount, frequency, and intensity in the United States SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID VARIABILITY; SNOWFALL AB Twentieth century trends of precipitation are examined by a variety of methods to more fully describe how precipitation has changed or varied. Since 1910, precipitation has increased by about 10% across the contiguous United States. The increase in precipitation is reflected primarily in the heavy and extreme daily precipitation events. For example, over half (53%) of the total increase of precipitation is due to positive trends in the upper 10 percentiles of the precipitation distribution. These trends are highly significant, both practically and statistically. The increase has arisen for two reasons. First, an increase in the frequency of days with precipitation [6 days (100 yr)(-1)] has occurred for all categories of precipitation amount. Second, for the extremely heavy precipitation events, an increase in the intensity of the events is also significantly contributing (about half) to the precipitation increase. As a result, there is a significant trend in much of the United States of the highest daily year-month precipitation amount, but with no systematic national trend of the median precipitation amount. These data suggest that the precipitation regimes in the United States are changing disproportionately across the precipitation distribution. The proportion of total precipitation derived from extreme and heavy events is increasing relative to more moderate events. These changes have an impact on the area of the United States affected by a much above-normal (upper 10 percentile) proportion of precipitation derived from very heavy precipitation events, for example, daily precipitation events exceeding 50.8 mm (2 in.). C1 NOAA, NESDIS, Natl Climat Data Ctr, Asheville, NC 28801 USA. RP Karl, TR (reprint author), NOAA, NESDIS, Natl Climat Data Ctr, 151 Patton Ave, Asheville, NC 28801 USA. NR 14 TC 681 Z9 749 U1 11 U2 73 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 FEB PY 1998 VL 79 IS 2 BP 231 EP 241 DI 10.1175/1520-0477(1998)079<0231:STOPAF>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ883 UT WOS:000072303900003 ER PT J AU Fritsch, JM Houze, RA Adler, R Bluestein, H Bosart, L Brown, J Carr, F Davis, C Johnson, RH Junker, N Kuo, YH Rutledge, S Smith, J Toth, Z Wilson, JW Zipser, E Zrnic, D AF Fritsch, JM Houze, RA Adler, R Bluestein, H Bosart, L Brown, J Carr, F Davis, C Johnson, RH Junker, N Kuo, YH Rutledge, S Smith, J Toth, Z Wilson, JW Zipser, E Zrnic, D TI Quantitative precipitation forecasting: Report of the eighth prospectus development team, US Weather Research Program SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material ID POTENTIAL VORTICITY AB Quantitative precipitation forecasting (QPF) is the most important and significant challenge of weather forecasting. Advances in computing and observational technology combined with theoretical advances regarding the chaotic nature of the atmosphere offer the possibility of significant improvement in QPF. To achieve these improvements, this report recommends research focusing on 1) improving the accuracy and temporal and spatial resolution of the rainfall observing system; 2) performing process and climatological studies using the modernized observing system; 3) designing new data-gathering strategies for numerical model initialization; and 4) defining a probabilistic framework for precipitation forecasting and verification. Advances on the QPF problem will require development of advanced ensemble techniques that account for forecast uncertainty, stemming from sampling error and differences in model physics and numerics and development of statistical techniques for using observational data to verify probabilistic QPF in a way that is consistent with the chaotic nature of the precipitation process. C1 Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. SUNY Albany, Dept Atmospher Sci, Albany, NY 12222 USA. NOAA, ERL, Forecast Syst Lab, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Natl Ctr Environm Predict, Hydrometeorol Predict Ctr, Camp Springs, MD USA. Princeton Univ, Dept Civil Engn & Operat Res, Princeton, NJ 08544 USA. Natl Ctr Environm Predict, Environm Modeling Ctr, Camp Springs, MD USA. Univ Texas, Dept Meteorol, College Stn, TX USA. Natl Severe Storms Lab, Norman, OK 73069 USA. RP Houze, RA (reprint author), Univ Washington, Dept Atmospher Sci, Box 351640, Seattle, WA 98195 USA. RI Toth, Zoltan/I-6624-2015; Brown, John/D-3361-2015 OI Toth, Zoltan/0000-0002-9635-9194; NR 15 TC 102 Z9 108 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD FEB PY 1998 VL 79 IS 2 BP 285 EP 299 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ883 UT WOS:000072303900007 ER PT J AU Marks, FD Shay, LK AF Marks, FD Shay, LK TI Landfalling tropical cyclones: Forecast problems and associated research opportunities SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material ID HURRICANE ANDREW LANDFALL; SURFACE WIND FIELDS; OCEAN RESPONSE; SOUTH FLORIDA; INTENSITY; RADAR AB The Fifth Prospectus Development Team of the U.S. Weather Research Program was charged to identify and delineate emerging research opportunities relevant to the prediction of local weather, flooding, and coastal ocean currents associated with landfalling U.S. hurricanes specifically, and tropical cyclones in general. Central to this theme are basic and applied research topics, including rapid intensity change, initialization of and parameterization in dynamical models, coupling of atmospheric and oceanic models, quantitative use of satellite information, and mobile observing strategies to acquire observations to evaluate and validate predictive models. To improve the necessary understanding of physical processes and provide the initial conditions for realistic predictions, a focused, comprehensive mobile observing system in a translating storm-coordinate system is required. Given the development of proven instrumentation and improvement of existing systems, three-dimensional atmospheric and oceanic datasets need to be acquired whenever major hurricanes threaten the United States. The spatial context of these focused three-dimensional datasets over the storm scales is provided by satellites, aircraft, expendable probes released from aircraft, and coastal (both fixed and mobile), moored, and drifting surface platforms. To take full advantage of these new observations, techniques need to be developed to objectively analyze these observations, and initialize models aimed at improving prediction of hurricane track and intensity from global-scale to mesoscale dynamical models. Multinested models allow prediction of all scales from the global, which determine longterm hurricane motion to the convective scale, which affect intensity. Development of an integrated analysis and model forecast system optimizing the use of three-dimensional observations and providing the necessary forecast skill on all relevant spatial scales is required. Detailed diagnostic analyses of these datasets will lead to improved understanding of the physical processes of hurricane motion, intensity change, the atmospheric and oceanic boundary layers, and the air-sea coupling mechanisms. The ultimate aim of this effort is the construction of real-time analyses of storm surge, winds, and rain, prior to and during landfall, to improve warnings and provide local officials with the comprehensive information required for recovery efforts in the hardest hit areas as quickly as possible. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Meteorol & Phys Oceanog, Miami, FL 33149 USA. RP Marks, FD (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. EM Frank.Marks@noaa.gov RI Marks, Frank/A-5733-2011; Powell, Mark/I-4963-2013; Black, Michael/C-3250-2014 OI Marks, Frank/0000-0003-0371-5514; Powell, Mark/0000-0002-4890-8945; Black, Michael/0000-0001-9528-2888 NR 21 TC 138 Z9 141 U1 4 U2 12 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 FEB PY 1998 VL 79 IS 2 BP 305 EP 323 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ883 UT WOS:000072303900009 ER PT J AU Bentz, DP Waller, V de Larrard, F AF Bentz, DP Waller, V de Larrard, F TI Prediction of adiabatic temperature rise in conventional and high-performance concretes using a 3-D microstructural model SO CEMENT AND CONCRETE RESEARCH LA English DT Article ID DSP CEMENT PASTES AB A series of conventional and high-performance concretes, with and without silica fume additions, have been prepared and characterized with respect to their adiabatic heat signature. The measured responses are compared with predicted values from the NIST 3-D cement hydration and microstructural model, which has been modified to incorporate the pozzolanic reaction of silica fume and to simulate hydration under adiabatic conditions. The latter modification is based on the activation energies and heats of reaction for the hydration and pozzolanic reactions and the heat capacity of the hydrating concrete mixture. For concretes with and without silica fume, the agreement between predicted and measured response is always within about five degrees Celsius. For concretes with silica fume, using an appropriate stoichiometry for the pozzolanic C-S-H is critical in matching the long-term (4 to 8 day) experimental temperature rise behavior. (C) 1998 Elsevier Science Ltd. C1 Lab Cent Ponts & Chaussees, F-75732 Paris 15, France. NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP de Larrard, F (reprint author), Lab Cent Ponts & Chaussees, 58 Bd Lefebvre, F-75732 Paris 15, France. NR 15 TC 59 Z9 65 U1 2 U2 15 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 FEB PY 1998 VL 28 IS 2 BP 285 EP 297 DI 10.1016/S0008-8846(97)00264-0 PG 13 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA YY442 UT WOS:000072147000015 ER PT J AU Black, PE AF Black, PE TI Edison's invention factory SO COMPUTER LA English DT Letter C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP Black, PE (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0018-9162 J9 COMPUTER JI Computer PD FEB PY 1998 VL 31 IS 2 BP 6 EP 6 PG 1 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA YW155 UT WOS:000071904000006 ER PT J AU Lenihan, HS Peterson, CH AF Lenihan, HS Peterson, CH TI How habitat degradation through fishery disturbance enhances impacts of hypoxia on oyster reefs SO ECOLOGICAL APPLICATIONS LA English DT Article DE biogenic reef habitat; Crassostrea virginica, decline of; ecosystem management; estuarine ecosystems; field experiment; habitat degradation through fishery disturbance; habitat structure; hypoxia effects; Neuse River estuary, North Carolina, USA; oyster reefs; reduced reef height of; water depth ID CHESAPEAKE BAY ANOXIA; PAMLICO RIVER ESTUARY; PREY REFUGES; SEA OTTERS; HISTORY; EUTROPHICATION; STRATIFICATION; COMMUNITIES; SETTLEMENT; PREDATION AB Oysters are ecosystem engineers that create biogenic reef habitat important to estuarine biodiversity, benthic-pelagic coupling, and fishery production, Prevailing explanations for the dramatic decline of eastern oysters (Crassostrea virginica) during the last century overlook ecosystem complexity by ignoring interactions among multiple environmental disturbances. To explain oyster loss, we tested whether (1) mortality of oysters on natural oyster reefs varies with water depth (3 m vs. 6 m), (2) harvesting by oyster dredges reduces the height of oyster reefs, and (3) bottom-water hypoxia/anoxia and reduction in reef height through fishery disturbance interact to enhance mortality of oysters in the Neuse River estuary, North Carolina, USA. The percentage of oysters found dead (mean +/- 1 SD) during a survey of natural reefs in May 1993 was significantly greater at 6-m (92 +/- 10%) than at 3-m (28 +/- 9%) water depth. Less than one season's worth of oyster dredging reduced the height of restored oyster reefs by similar to 30%. During stratification of the water column in summer, oxygen depletion near the seafloor at 6 m caused mass mortality of oysters, other invertebrates, and fishes on short, deep experimental reefs, while oysters and other reef associates elevated into the surface layer by sufficient reef height or by location in shallow water survived. Highly mobile blue crabs (Callinectes sapidus) abandoned burrows located in hypoxic/anoxic bottom waters but remained alive in shallow water, Our results indicate that interaction of reef habitat degradation (height reduction) through fishery disturbance and extended bottom-water hypoxia/anoxia caused the pattern of oyster mortality observed on natural reefs and influences the abundance and distribution of fish and invertebrate species that utilize this temperate reef habitat. Interactions among environmental disturbances imply a need for the integrative approaches of ecosystem management to restore and sustain estuarine habitat. C1 Univ N Carolina, Inst Marine Sci, Morehead City, NC 28557 USA. RP Lenihan, HS (reprint author), NOAA, Natl Marine Fisheries Serv, Beaufort Lab, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 83 TC 228 Z9 231 U1 8 U2 56 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD FEB PY 1998 VL 8 IS 1 BP 128 EP 140 DI 10.2307/2641316 PG 13 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA YX701 UT WOS:000072068200011 ER PT J AU Fogarty, MJ Murawski, SA AF Fogarty, MJ Murawski, SA TI Large-scale disturbance and the structure of marine system: Fishery impacts on Georges Bank SO ECOLOGICAL APPLICATIONS LA English DT Article; Proceedings Paper CT International Meeting on the State of Fisheries CY FEB, 1996 CL MONTEREY, CALIFORNIA SP US Natl Res Council, Ocean Study Board DE community structure, changes; disturbance; ecosystem management; exploitation; Georges Bank; habitat destruction and degradation; indirect effects of harvesting; marine fisheries, management; spatial structure; species-selective harvesting; sustainability ID HADDOCK MELANOGRAMMUS-AEGLEFINUS; COD GADUS-MORHUA; ECOSYSTEM MANAGEMENT; CLIMATE-CHANGE; UNITED-STATES; RECRUITMENT; MODEL; VARIABILITY; RESOURCES; PREDATION AB Georges Bank, a shallow submarine plateau located off the New England coast, has supported valuable commercial fisheries for several centuries. The region is characterized by high levels of primary productivity and, historically, high levels of fish production, Within the last four decades Georges Bank has been subjected to major perturbations that have profoundly altered levels of catch, abundance, and species composition. The arrival of distant water Beets during the early 1960s resulted in dramatic increases in effective fishing effort and the subsequent commercial collapse of several fish populations. Total fish biomass is estimated to have declined by >50% on Georges Bank during the period of operation of the distant water Beets, The implementation of extended jurisdiction (the 200-mile [370.4-km] limit) in 1977 was followed by modernization and increased capacity of the domestic Beet, resulting in a second perturbation to the system that resulted in further declines in groundfish populations to historically low levels, A subsequent increase in the abundance of species of low commercial value was documented, with an apparent replacement of gadid and Bounder species by small elasmobranchs (including dogfish sharks and skates), Examination of feeding guild structure suggests that this switch in species dominance may have been Linked to a competitive release, The small elasmobranchs, notably dogfish sharks, also prey on species of commercial importance (primarily small pelagics, including herring and mackerel), The cumulative impacts on the groundfish populations as a result of intense exploitation and predation pressure may have been further exacerbated by effects of fishing gear on the physical structure of the habitat. Implications for the development of an ecosystem-based management approach are described. C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Fogarty, MJ (reprint author), Univ Maryland Syst, Ctr Environm & Estuarine Studies, Chesapeake Biol Lab, POB 38, Solomons, MD 20688 USA. NR 110 TC 241 Z9 248 U1 2 U2 58 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD FEB PY 1998 VL 8 IS 1 SU S BP S6 EP S22 DI 10.1890/1051-0761(1998)8[S6:LDATSO]2.0.CO;2 PG 17 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA YY621 UT WOS:000072166600003 ER PT J AU Hartwell, SI Dawson, CE Durell, EQ Alden, RW Adolphson, PC Wright, DA Coelho, GM Magee, JA AF Hartwell, SI Dawson, CE Durell, EQ Alden, RW Adolphson, PC Wright, DA Coelho, GM Magee, JA TI Integrated measures of ambient toxicity and fish community diversity in Chesapeake Bay tributaries SO ECOTOXICOLOGY LA English DT Article DE ambient toxicity; community diversity; sediment AB The goals of this study were to assess the results of a suite of sediment and water column bioassays in the framework of a toxicological risk ranking model and evaluate correlations of model output with fish community metrics. The test sites were located in four tributaries of Chesapeake Bay that are impacted on by industrial, urban and agricultural land use (Curtis Creek, Rock Creek, Fishing Bay and Wicomico River). The mortality, reproduction and growth rates in the water column assays indicated low-level chemical contamination impacts in Curtis Creek and Rock Creek. The results from the Wicomico River and Fishing Bay did not indicate contaminant impacts, but some borderline effects were seen. The sediment bioassays demonstrated greater toxicological responses than the water column assays. The sediments in the Curtis Creek and Rock Creek sites were contaminated with heavy metals and PAHs. The heavy metal concentrations were an order of magnitude lower in the Fishing Bay sediments and below detection in the Wicomico River sediments, except for zinc. The acid-volatile sulphides:simultaneously extractable metals (AVS:SEM) ratios were below 1 in all cases. All four systems had detectable petroleum hydrocarbon contamination. Organic contaminants were below detection for all analyses in the Wicomico River and Fishing Bay samples. The risk ranking model ranked Curtis Creek as the most toxicologically impacted site, followed by Rock Creek, Fishing Bay and Wicomico River, which were essentially equal. The diversity index for fish communities sampled by bottom trawl was significantly correlated with the toxicological risk scores for sediment. The toxicological results indicate sediment contamination effects on the deep water fish community in Curtis Creek and indicate that contaminant impacts are not likely to be a contributing factor to disturbed fish communities in Fishing Bay. C1 Maryland Dept Nat Resources, Tiedwater Ecosyst Assessment Div, Annapolis, MD 21401 USA. Old Dominion Univ, Appl Marine Res Lab, Norfolk, VA 23529 USA. Univ Maryland, Chesapeake Biol Lab, Solomons, MD 20688 USA. RP Hartwell, SI (reprint author), NOAA, Natl Marine Fisheries Serv, 1315 E W Hwy,F-HC, Silver Spring, MD 20910 USA. NR 27 TC 10 Z9 12 U1 1 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0963-9292 J9 ECOTOXICOLOGY JI Ecotoxicology PD FEB PY 1998 VL 7 IS 1 BP 19 EP 35 PG 17 WC Ecology; Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA YX819 UT WOS:000072082800003 ER PT J AU O'Connell, CD Tian, J Juhasz, A Wenz, HM Atha, DH AF O'Connell, CD Tian, J Juhasz, A Wenz, HM Atha, DH TI Development of standard reference materials for diagnosis of p53 mutations: Analysis by slab gel single strand conformation polymorphism SO ELECTROPHORESIS LA English DT Article DE DNA standards; p53 mutation detection; slab gel electrophoresis; single-strand conformation polymorphism ID PCR-SSCP ANALYSIS; CELL-LINES; BREAST-CANCER; PROGNOSTIC VALUE; GENE-MUTATIONS; DATABASE; TUMORS; DNA AB We have amplified by polymerase chain reaction (PCR) a 2.0 kbp region of the p53 gene containing exons 5-9 from seven cell lines reported in the literature to contain the majority of mutations reported for this gene. Sequence analysis of these products show that all seven cell lines contain mutations within the mutational hot spots of the p53 gene. Six of the seven clones have single base substitutions and the seventh has a single base deletion, We have analyzed the seven p53 single point mutations by single strand conformation polymorphism (SSCP) analysis using fluorescence slab gel electrophoresis (SG-SSCP). Fluorescent-labeled PCR primers were used for amplification of specific exons for mutation detection. SC-SSCP was conducted using Model 373 and Model 377 DNA sequencers with GeneScan Software (Perkin Elmer, Applied Biosystem Division), Nine different gel systems were first tested for their ability to resolve the p53 mutations using the Model 373 instrument. Two gel systems were capable of resolving all of the mutations that were screened. Optimal results were obtained with 12% w/v acrylamide 50:1 plus 10% v/v glycerol. This gel system was used to evaluate the effect of temperature on the ability to resolve the mutations. The separation with respect to wild type varied for each mutation examined. Subambient temperature (20 degrees C) was preferable overall for discrimination of these mutations as a group. We intend to use this system to examine a much larger panel of p53 mutation standards that are now under development. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. Perkin Elmer, Appl Biosyst Div, Foster City, CA USA. RP O'Connell, CD (reprint author), NIST, Div Biotechnol, Bldg 222,Rm A353, Gaithersburg, MD 20899 USA. EM catherine.oconnell@nist.gov NR 21 TC 20 Z9 20 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD FEB PY 1998 VL 19 IS 2 BP 164 EP 171 DI 10.1002/elps.1150190206 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA ZB078 UT WOS:000072433100005 PM 9548275 ER PT J AU Atha, DH Wenz, HM Morehead, H Tian, J O'Connell, CD AF Atha, DH Wenz, HM Morehead, H Tian, J O'Connell, CD TI Detection of p53 point mutations by single strand conformation polymorphism: Analysis by capillary electrophoresis SO ELECTROPHORESIS LA English DT Article DE DNA p53 mutation detection; capillary electrophoresis; slab gel electrophoresis; single strand conformation polymorphism; temperature dependence ID PCR-SSCP ANALYSIS; DNA FRAGMENTS AB We have analyzed five p53 single point mutations by single strand conformation polymorphism using capillary electrophoresis (CE-SSCP) and have compared these measurements to measurements obtained by slab gel electrophoresis (SG-SSCP). PCR primers were used for amplification of specific exons for mutation detection. 5' Primers were labeled with FAM (5-carboxyfluorescein) and 3' primers were labeled with JOE (2',7'-dimethoxy-4',5'-dichloro-6-carboxyfluorescein). CE-SSCP was performed using the Perkin Elmer ABI PRISM(TM) 310 Genetic Analyzer with GeneScan(TM) Software and the Beckman P/ACE(TM) 5510 CE equipped for laser-induced fluorescence detection. Although the shifts in migration times for the p53 mutations relative to the corresponding wild-type strands could be successfully detected by either SG or CE analysis, the individual electrophoresis run times were about tenfold faster and more automated with capillary electrophoresis. The CE-SSCP measurements were performed at temperatures ranging from 10 to 60 degrees C on a prototype instrument. For mutations measured at ambient temperature (25 degrees C), characteristic shifts in direction and magnitude were observed in the migration times of both strands of all mutations relative to the wild type. This demonstrated the ability of CE at ambient temperature to resolve these mutations. However, the magnitute and direction of shifts in migration time varied with temperature in a discrete pattern for each mutation and resulted in a temperature-specific profile for each mutation. This demonstrated that extended temperature control will be an important advantage in resolving single point mutations by CE-SSCP. In addition, by using CE, discrete intra-strand isoforms could be easily observed at different temperatures. The combination of mutation-specific temperature profiling and analysis of isoforms by CE-SSCP should be of help to the diagnostic community in the detection of genetic mutations. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. Perkin Elmer, Appl Biosyst Div, Foster City, CA USA. RP Atha, DH (reprint author), NIST, Div Biotechnol, Bldg 222,Rm A-353, Gaithersburg, MD 20899 USA. EM donald.atha@nist.gov NR 18 TC 56 Z9 62 U1 0 U2 5 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD FEB PY 1998 VL 19 IS 2 BP 172 EP 179 DI 10.1002/elps.1150190207 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA ZB078 UT WOS:000072433100006 PM 9548276 ER PT J AU Brodeur, RD AF Brodeur, RD TI Prey selection by age-0 walleye pollock, Theragra chalcogramma, in nearshore waters of the Gulf of Alaska SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE juvenile fish; feeding; zooplankton; prey selectivity ID WESTERN GULF; ELECTIVITY INDEXES; JUVENILE; SIZE; FISH; LARVAL; PLANKTIVORES; PREDATION; BEHAVIOR; LEPOMIS AB Juvenile walleye pollock, Theragra chalcogramma, is the dominant forage fish on the continental shelf of the Gulf of Alaska, yet little is known about the feeding habits of this important interval of pollock life history. The taxonomic composition and size of prey found in the stomachs of age-0 juveniles collected at three nearshore locations in the Gulf of Alaska in September 1990 were compared to the composition and size of zooplankton collected in concurrent plankton tows. The maximum length of prey consumed increased dramatically over the length range of pollock examined (58-110 mm) from approximately 7 mm to 30 mm, due mainly to the consumption of large euphausiids and chaetognaths by the bigger individuals. The maximum width of prey changed little over this size range although there was a general increase in prey width with increasing predator size. The minimum prey length and width did not change with increasing fish size. Juvenile pollock generally selected the larger prey sizes relative to what was available. Juvenile pollock showed a marked preference for adult euphausiids and decapod larvae and an avoidance of copepods and chaetognaths relative to the numbers collected in net tows. These results are discussed relative to the feeding ecology of these juvenile fishes. C1 Natl Marine Fisheries Serv, NOAA, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Brodeur, RD (reprint author), Natl Marine Fisheries Serv, NOAA, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. EM rbrodeur@afsc.noaa.gov NR 42 TC 45 Z9 47 U1 0 U2 12 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD FEB PY 1998 VL 51 IS 2 BP 175 EP 186 DI 10.1023/A:1007455619363 PG 12 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA YW832 UT WOS:000071978500007 ER PT J AU Rasberry, SD AF Rasberry, SD TI Reference materials in the world of tomorrow SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements AB Good projections about the use of reference materials (RMs) in the world of tomorrow are especially important to RM producers. They need to know what kinds of RMs will be required in the future, by whom, and for what purposes. They need to know what batch sizes to prepare of different kinds and how to allocate limited resources to best effect. The following steps may provide a useful view of the future of reference materials: (1) Review of trends, (2) Projection of challenges, (3) Analysis of driving forces and construction of scenarios, (4) Thinking "outside the box," and (5) Selecting strategies. This paper will illustrate the use of these steps for the field of reference materials in order to provide a framework for the role of reference materials in the world of tomorrow. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Rasberry, SD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 8 TC 16 Z9 16 U1 0 U2 0 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 FEB PY 1998 VL 360 IS 3-4 BP 277 EP 281 DI 10.1007/s002160050692 PG 5 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700002 ER PT J AU Iyengar, V Wolf, W AF Iyengar, V Wolf, W TI Global activities in the world of reference materials including the needs of developing countries SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements ID BIOLOGICAL SAMPLES AB Proceedings of previous BERM meetings have been used to assess emerging trends in the development of RMs to meet AQC requirements of clinical, food, nutrition, and environmental health areas. BRM-1 reflected a strong need to initiate and expand RM activities for certifying organic nutrients in foods. BRM-2 highlighted the distinction between primary (certified) and secondary (e.g. check samples for proficiency testing) RMs1. BRM-3 identified the need for producing different levels of an analyte in a given matrix (spiked standards) to address matrix related measurement problems in foods. BERM-4 highlighted the need for a global vision in dealing with standards, illustrated by the activities of GESREM. Also, the logistics required for setting up inter comparison programs related to food safety monitoring programs were outlined. BERM-5 presented the changing outlook of the AOAC International in recognizing the usefulness of incorporating RMs for use in conjunction with their methods validation protocol. BERM-6 brought to the forefront the concern for traceability of chemical measurements to internationally recognized standards. BERM-7 recognized the need for multidisciplinary approaches for preparing certain types of CRMs, partly in response to the measurement needs arising from governmental regulations dealing with food safety and environmental health criteria. Finally, BERM symposia have promoted a meaningful dialogue on the RM needs of African, Asian and South American countries and provided the developing countries opportunities to discuss their problems with the international analytical community. The issue of health safety is involved in movement of foodstuffs between countries, and therefore, international efforts as voiced by the World Health Organization to provide guidance and assistance in AQC matters to the needy countries deserve consideration. C1 NIST, SRMP, Gaithersburg, MD 20899 USA. USDA, BHNRC, Beltsville, MD 20705 USA. RP Iyengar, V (reprint author), NIST, SRMP, Gaithersburg, MD 20899 USA. NR 22 TC 2 Z9 2 U1 0 U2 0 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 FEB PY 1998 VL 360 IS 3-4 BP 282 EP 286 DI 10.1007/s002160050693 PG 5 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700003 ER PT J AU Welch, M Colbert, J AF Welch, M Colbert, J TI Certification strategies for health-related SRMS at NIST SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements ID DILUTION MASS-SPECTROMETRY; CANDIDATE DEFINITIVE METHOD; SERUM; ACCURACY AB Inaccuracy in health-related measurements raises overall health care costs, results in misdiagnoses, leads to inaccurate conclusions in clinical studies, and results in inaccurate nutrition labeling. NIST has an extensive program aimed at providing the health measurements community with standard reference materials (SRMs) to assist them in making accurate measurements. A variety of approaches are used to certify health-related SRMs. For pure crystalline SRMs used as primary standards, direct assays of purity are often not possible. Thus numerous techniques including differential scanning calorimetry, mass spectrometry, chromatography, and others may be used to assess purity. For matrix SRMs used to assess the accuracy of measurement systems, the approaches for certification depend upon the needs of the users and NIST capabilities. When accuracy needs are the highest and the methods exist, NIST uses definitive methods, primarily involving isotope dilution mass spectrometry. These methods have been applied to the certification of serum-based SRMs for a number of the common clinical analytes. For many analytes, definitive methods have not been developed, so NIST uses other strategies for certification. In some cases, such as for drugs of abuse, two independent methods are used for the measurements. For nutrients such as vitamins, in-house methods are used along with results from outside laboratories having extensive experience with a particular analysis. The paper includes tables with examples of many of the health-related SRMs that are available. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Welch, M (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 14 TC 4 Z9 4 U1 0 U2 0 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 FEB PY 1998 VL 360 IS 3-4 BP 312 EP 316 DI 10.1007/s002160050700 PG 5 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700010 ER PT J AU Lindstrom, RM AF Lindstrom, RM TI Reference material certification by prompt-gamma activation analysis SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements ID STANDARD REFERENCE MATERIALS; MULTIELEMENT DETERMINATION; RAY ANALYSIS; NEUTRON; ELEMENTS; INAA; COLD; HOMOGENEITY; SCATTERING; FACILITY AB Neutron-capture prompt-gamma-ray activation analysis (PGAA) shares most of the virtues of instrumental neutron activation analysis (INAA) for reference material certification: highly penetrating probe and response radiation, simple physics, and few interelement interferences or matrix related non-linearities. PGAA complements INAA in determining a different suite of elements using the same tools: a neutron source and gamma-ray spectrometry. Several important elements that are difficult to measure by other techniques are measurable by PGAA, notably H, B, C, N, and S. A survey of published applications and NIST Standard Reference Material certification work shows over thirty different SRMs analyzed by PGAA, including biological materials (botanical and food), coal and fly ash, metals, and several other matrices. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Lindstrom, RM (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 26 TC 8 Z9 8 U1 0 U2 2 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 FEB PY 1998 VL 360 IS 3-4 BP 322 EP 324 DI 10.1007/s002160050702 PG 3 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700012 ER PT J AU Lindstrom, RM Asvavijnijkulchai, C AF Lindstrom, RM Asvavijnijkulchai, C TI Ensuring accuracy in spreadsheet calculations SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements AB Spreadsheet programs have become ubiquitous and indispensable in the laboratory. Data may be easily entered and manipulated without the need to learn a programming language or consult a statistician. Spreadsheets are numerically robust and easily altered with a few mouse-clicks to accommodate changing needs. Ease of use, however, implies ease of making errors. Data can be entered in place of equations when a sheet is expanded, sometimes without immediately obvious consequences. Errors can be made less likely to occur by paying attention to the design of the worksheet as it is constructed. Input cells can be formatted to delineate input clearly from output. The sheet can be annotated with titles and notes. Named variables aid understanding and error tracing. Modular blocks of code can add clarity. Logical tests should be included to allow for the occurrence of blank cells, zeroes, and negative numbers. The output should display the values of the important parameters used in the calculation as well as the final result. A finished worksheet needs to be tested to assure accuracy. Standard test data should be used to recheck a sheet's reliability after it is modified. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. Off Atom Energy Peace, Div Phys, Bangkok 10900, Thailand. RP Lindstrom, RM (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 5 TC 2 Z9 2 U1 0 U2 0 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 FEB PY 1998 VL 360 IS 3-4 BP 374 EP 375 DI 10.1007/s002160050715 PG 2 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700025 ER PT J AU Zeisler, R AF Zeisler, R TI Reference materials for small-sample analysis SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements AB Many modem analytical techniques use small solid samples and lack proper reference materials for their calibration and quality assurance. A remedy to this deficiency may be in the development of a new genre of highly homogeneous natural matrix materials, their properties being studied with analytical techniques such as PIXE and CL-PIXE, solid sampling AAS, scanning electron microscopy in combination with electron probe X-ray microanalysis, and INAA. Suitable natural materials may be obtained in form of single cell biological materials, finely dispersed suspensions and precipitates such as air particulate matter or sediments, and by appropriate particle size reduction of complex matrices. Initial studies have been carried out on single cell green algae biomass and air particulate matter, as well as several processed materials. Narrow particle size distributions with particles preferably below 10 mu m diameter may assure the desired analytical homogeneity. The determination of sampling parameters for individual measurands will ascertain the utility of a material for small-sample analysis. 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 6 TC 30 Z9 32 U1 2 U2 9 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 FEB PY 1998 VL 360 IS 3-4 BP 376 EP 379 DI 10.1007/s002160050716 PG 4 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700026 ER PT J AU Chu, PM Rhoderick, GC Van Vlack, D Wetzel, SJ Lafferty, WJ Guenther, FR AF Chu, PM Rhoderick, GC Van Vlack, D Wetzel, SJ Lafferty, WJ Guenther, FR TI A quantitative infrared spectral database of hazardous air pollutants SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements ID (H2O)-O-16; STANDARDS; STRENGTHS AB Open-path monitoring of the atmosphere using Fourier transform infrared spectrometry has recently become a useful real-time in situ analytical technique. The U.S. Environmental Protection Agency (EPA) is currently formulating Method TO-16, a protocol for infrared remote sensing of the hazardous air pollutants (HAPs) identified in EPA's Clean Air Act of 1990. To support infrared based sensing technologies, the National Institute of Standards and Technology (NIST) is currently developing a standard quantitative spectral database of the HAPs based on gravimetrically prepared samples. This paper presents the protocol used to prepare the gravimetric mixtures and initial results. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Chu, PM (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 10 TC 4 Z9 5 U1 3 U2 5 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 FEB PY 1998 VL 360 IS 3-4 BP 426 EP 429 DI 10.1007/s002160050728 PG 4 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700038 ER PT J AU Zeisler, R Dekner, R Zeiller, E Doucha, J Mader, P Kucera, J AF Zeisler, R Dekner, R Zeiller, E Doucha, J Mader, P Kucera, J TI Single cell green algae reference materials with managed levels of heavy metals SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements AB Three batches of single cell green algal biomass have been produced as model substances for green biomass reference materials with the aim of arriving at three different concentration levels for selected heavy metals in the same matrix. The green algal biomass is produced in a water based culture medium in open and closed bioreactors. An outdoor open bioreactor technology was used to produce a batch of "natural level" algae as well as a batch with elevated levels of As, Cd, Cr, Hg, Ni, and Pb. A photoreactor constructed without metal parts and employing artificial light sources was used in a clean air environment with high purity chemicals to reduce heavy metal concentrations in the third batch of algal biomass. For the above elements, the depleted level material, with exception of Hg, showed about one order of magnitude lower concentration than the natural level, while concentrations in the enriched material were up to four orders of magnitude higher. Analysts can use these materials to sustain verification of calibration and analytical quality over the entire operational range of the analytical work. C1 Int Atom Energy Agcy, Labs Seibersdorf, A-1400 Vienna, Austria. Acad Sci Czech Republ, Inst Microbiol, CZ-37981 Trebon, Czech Republic. Czech Univ Agr, Dept Chem, CZ-16521 Prague, Suchdol, Czech Republic. Acad Sci Czech Republ, Inst Nucl Phys, CZ-25068 Rez, Czech Republic. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Zeisler, R (reprint author), Int Atom Energy Agcy, Labs Seibersdorf, POB 100, A-1400 Vienna, Austria. RI Kucera, Jan/G-8507-2014 NR 7 TC 5 Z9 5 U1 0 U2 4 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 FEB PY 1998 VL 360 IS 3-4 BP 429 EP 432 DI 10.1007/s002160050729 PG 4 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700039 ER PT J AU Heller-Zeisler, SF Fajgelj, A Bernasconi, G Tajani, A Zeisler, R AF Heller-Zeisler, SF Fajgelj, A Bernasconi, G Tajani, A Zeisler, R TI Examination of a procedure for the production of a simulated filter-based air particulate matter reference material SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements AB An approach for producing simulated air particulate matter (APM) deposited on filters has been developed and investigated as to its usefulness for yielding large batches of filters as a future reference material. The APM deposited on the filters was a material collected from an urban industrial area, and had been milled to approximate a material of PM-2.5 particle size distribution. The milled APM material was loaded onto filter substrates (Nuclepore) through the deposition of aliquots from a liquid suspension via vacuum filtration. It should be noted that these filters do not represent a typical PM-2.5 elemental composition, since the milling increased the proportion of crustal materials and the suspension in liquid decreased the sulfate content. Homogeneity between filters was tested using INAA (whole filter analysis) and ED-XRF and PIXE and was estimated to be in the 5% range (relative standard deviation). Homogeneity within the filters and among the filters was also tested using micro-XRF and found to be acceptable for the elements tested. The results of the tests carried out on the filters indicate that this approach is appropriate for large-scale production of similar filters for distribution as reference materials. C1 Int Atom Energy Agcy, Dept Res & Isotopes, A-1400 Vienna, Austria. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Heller-Zeisler, SF (reprint author), Int Atom Energy Agcy, Dept Res & Isotopes, POB 100, A-1400 Vienna, Austria. NR 9 TC 15 Z9 15 U1 1 U2 3 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 FEB PY 1998 VL 360 IS 3-4 BP 435 EP 438 DI 10.1007/s002160050731 PG 4 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700041 ER PT J AU Fajgelj, A Zeisler, R AF Fajgelj, A Zeisler, R TI Particle size determination of some IAEA and NIST environmental and biological reference materials SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements ID TRACE AB Particle size distributions in fifteen International Atomic Energy Agency (IAEA) and sixteen National Institute of Standards and Technology (NIST) reference materials (RMs) were measured with the basic aim to investigate the potential of these materials to be used as reference or quality control materials in analyses where a small sample mass is required (< 100 mg). Most of the investigated materials are commercially available environmental or biological natural matrix RMs with certified values for trace elements, radionuclides, or organometallic compounds. The laser diffraction technique was used in all measurements. From the point of particle size distribution, materials IAEA-390 (Algae, a set of three materials), IAEA-396m (Urban Dust, 3x air jet milled), NIST-SRM 1515 (Apple Leaves), NIST-SRM 1547 (Peach Leaves), NIST-SRM 1566a (Oyster Tissue), NIST-SRM 1570a (Spinach), NIST-SRM 1573a (Tomato Leaves), and NIST-SRM 1648 (Urban Particulate) can be considered appropriate for small sample mass analysis. However, additional analytical tests are needed to confirm the appropriate homogeneous distribution of chemical composition, the level of heterogeneity for individual elements, at this sample mass level. C1 Int Atom Energy Agcy, Dept Res & Isotopes, A-1400 Vienna, Austria. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Fajgelj, A (reprint author), Int Atom Energy Agcy, Dept Res & Isotopes, POB 100, A-1400 Vienna, Austria. NR 6 TC 8 Z9 8 U1 1 U2 8 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 FEB PY 1998 VL 360 IS 3-4 BP 442 EP 445 DI 10.1007/s002160050733 PG 4 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700043 ER PT J AU Sharpless, KE Welch, MJ Greenberg, RR Iyengar, GV Colbert, JC AF Sharpless, KE Welch, MJ Greenberg, RR Iyengar, GV Colbert, JC TI Recent SRMs for organic and inorganic nutrients in food matrices SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Symposium on Biological and Environmental Reference Materials (BERM-7) CY APR 21-25, 1997 CL ANTWERP, BELGIUM SP European Commiss, AOAC Int, European Inst Reference Mat & Measurements AB The National Institute of Standards and Technology (NIST) has recently introduced several reference materials for organic and inorganic nutrients in food matrices to assist the food industry in complying with nutrition labeling laws; the food industry and other government agencies have collaborated with NIST in this endeavor. Two food-matrix SRMs were issued in 1996: SRM 1544, Fatty Acids and Cholesterol in Frozen Food Composite; and SRM 1846, Infant Formula. Concentration values in SRM 1544 are provided for six fatty acids, cholesterol, and proximates (fat, protein, carbohydrate, etc.). Values are assigned for proximate and caloric content as well as the concentrations of sixteen vitamins and nine minerals and trace elements in SRM 1846. In 1997, NIST expects to issue two additional food-matrix SRMs: SRM 1548a, Typical Diet, and SRM 2383, Baby Food Composite. SRM 1548a will replace SRM 1548, Total Diet, and will have values assigned for proximates, major and minor inorganic nutrients, and toxic trace elements. SRM 2383 will have values assigned for proximates, vitamins, carotenoids, and inorganic nutrients. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sharpless, KE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 5 TC 3 Z9 3 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 FEB PY 1998 VL 360 IS 3-4 BP 456 EP 458 DI 10.1007/s002160050738 PG 3 WC Chemistry, Analytical SC Chemistry GA ZB305 UT WOS:000072457700048 ER PT J AU Larsen, DA Swanson, P Dickey, JT Rivier, J Dickhoff, WW AF Larsen, DA Swanson, P Dickey, JT Rivier, J Dickhoff, WW TI In vitro thyrotropin-releasing activity of corticotropin-releasing hormone-family peptides in coho salmon, Oncorhynchus kisutch SO GENERAL AND COMPARATIVE ENDOCRINOLOGY LA English DT Article ID AMINO-ACID-SEQUENCE; UROTENSIN-I; THYROID-HORMONES; PITUITARY-CELLS; TELEOST FISH; AMPHIBIAN METAMORPHOSIS; MAMMALIAN THYROTROPIN; GOLDFISH PITUITARY; RAINBOW-TROUT; SECRETION AB Investigations of hypothalamic regulation of fish thyrotropin (TSH) secretion and subsequent thyroid activity have been impeded by the lack of a reliable assay for TSH. Using a recently developed radioimmunoassay (RIA) for coho salmon TSH we employed an in vitro pituitary cell culture technique to examine regulation of TSH secretion by corticotropin-releasing hormone (CRH) family peptides [ovine CRH (oCRH), carp urotensin I (UI), and frog sauvagine (SV)] as well as thyrotropin-releasing hormone (TRH), salmon growth hormone-releasing hormone (sGHRH). and salmon gonadotropin-releasing hormone (sGnRH). At concentrations of 0.01 to 100 nM, TRH, sGHRH, and sGnRH did not stimulate TSH secretion from coho salmon pituitary cells. However, at these same concentrations, both oCRH and SV caused a significant and concentration-dependent increase in TSH secretion; whereas, UI was highly stimulatory at all concentrations tested. In a related experiment we examined the effect of alpha-helical CRF(9-41) on oCRH-stimulated TSH release by pituitary cells. alpha-Helical CRF(9-41) is an analogue of CRH that has been shown by others to antagonize the adrenocorticotropic hormone (ACTH)-releasing activity of CRH in goldfish. Preincubation of cells with 1 mu M alpha-helical CRF(9-41) for 4 h caused a significant suppression of the TSH-releasing activity of oCRH at 1.0 and 10 nM concentrations. The results of these experiments demonstrate the potency of a CRH-like peptide in the hypothalamic regulation of TSH in fish and reveal similarities in the inhibition of the response of both the thyroid and interrenal axis of fish to alpha-helical CRF(9-41). (C) 1998 Academic Press. C1 Natl Marine Fisheries Serv, Integrat Fish Biol Lab, NW Fisheries Sci Ctr, NOAA, Seattle, WA 98112 USA. Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. Salk Inst Biol Studies, Clayton Fdn Labs Peptide Biol, La Jolla, CA 92037 USA. RP Larsen, DA (reprint author), Natl Marine Fisheries Serv, Integrat Fish Biol Lab, NW Fisheries Sci Ctr, NOAA, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 67 TC 68 Z9 73 U1 0 U2 4 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0016-6480 EI 1095-6840 J9 GEN COMP ENDOCR JI Gen. Comp. Endocrinol. PD FEB PY 1998 VL 109 IS 2 BP 276 EP 285 DI 10.1006/gcen.1997.7031 PG 10 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA YW242 UT WOS:000071912700014 PM 9473372 ER PT J AU Russell, SS Huss, GR Fahey, AJ Greenwood, RC Hutchison, R Wasserburg, GJ AF Russell, SS Huss, GR Fahey, AJ Greenwood, RC Hutchison, R Wasserburg, GJ TI An isotopic and petrologic study of calcium-aluminum-rich inclusions from CO3 meteorites SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Review ID UNUSUAL ALLENDE INCLUSION; RARE-EARTH ELEMENTS; MURCHISON CARBONACEOUS CHONDRITE; EARLY SOLAR-SYSTEM; REFRACTORY INCLUSIONS; PARTITION-COEFFICIENTS; TRACE-ELEMENTS; ION MICROPROBE; HIBONITE; AL-26 AB We have studied the mineralogy and petrology of 229 calcium-aluminum-rich inclusions (CAIs) from ten CO3 meteorites of petrologic types 3.0-3.7. Subsets of these inclusions were measured by ion probe for magnesium, calcium, and titanium isotopes and REE abundances. Most CAIs from CO3 meteorites fall into three major types: (1) melilite-rich inclusions, which also contain spinel/hercynite, perovskite, and occasionally hibonite; (2) spinel-pyroxene inclusions: and (3) hibonite-hercynite inclusions. In addition, several isolated hibonite grains, two grossite (CaAl4O7) bearing CAIs, two hibonite-fassaite microspherules, and one anorthite-spinel-pyroxene inclusion were found. CAIs from CO3 meteorites exhibit all of the REE patterns commonly seen in inclusions from CV3 and CM2 chondrites. Most exhibit evidence of Al-26, and many have inferred (Al-26/Al-27)(o) approximate to 5 x 10(-5). The relative abundances of different types of CAIs in CO3 chondrites differ from those in CV3 and CM2 chondrites. CAIs in CO3 chondrites have experienced considerable secondary alteration, both before and after accretion. Signatures of nebular alteration include Wark-Lovering rims and the high Fe contents in spinels from all hibonite/hercynite inclusions. Occasionally, melilite and acorthite show evidence of nebular alteration to feldspathoids and pyroxene. The magnesium-aluminum systematics of some melilite-rich inclusions were apparently disturbed prior to final accretion of the parent body. Parent body alteration is indicated by correlations between CAI characteristics and the petrologic type of the host meteorite. Spinel in melilite-rich and coarse-grained spinel-pyroxene inclusions becomes more Fe rich, with the development of relatively homogeneous hercynitic spinel (similar to 50-60 mol%) in CAIs from metamorphic grades >3.4. Perovskite has been converted to ilmenite in types >3.4. Melilite-rich inclusions are abundant in CO3.0-3.3 meteorites, rare in 3.4 meteorites, and absent meteorites of types 3.5-3.7; melilite-rich CAIs are probably replaced by inclusions rich in feldspathoids, pyroxene, and Fe-rich spinel. Isotopic disturbance of the magnesium-aluminum systematics may be more severe in higher petrologic types. Hibonite seems to be unaffected by this level of metamorphism. Three isotopically unusual inclusions were found. One single-crystal hibonite, Isna SP16, has a REE pattern strongly depleted in Ce and Y. (Al-26/Al-27)(o) = (2.4 +/- 0.3) x 10(-5), and mass fractionated calcium (F-Ca = +12 +/- 2 parts per thousand/amu), but no resolvable nuclear anomalies in neutron-rich calcium isotopes. The REE pattern, which is thought to reflect nebular conditions, and mass-fractionated calcium, indicative of evaporation, are similar to those of the FUN inclusion, HAL, and related hibonites, indicating similar formation conditions. The absence in Isna SP16 of the nuclear anomalies observed in HAL and the difference in (Al-26/Al-27)(o) between HAL and Isna SP16 indicate that the processes that produced HAL-type hibonites operated on diverse materials. Two hibonite-bearing microspherules, Colony SP1 and ALH82101 SP15, exhibit nearly flat REE patterns with negative europium anomalies and slightly negative delta(26)Mg. ALH82101 SP15 has resolved excesses of Ca-48 and Ti-50. These characteristics are similar to those of previously described microspherules from Murchison and Lance, implying that the microspherules formed via a single process from related, but not identical source materials. Copyright (C) 1998 Elsevier Science Ltd. C1 CALTECH, Dept Geol & Planetary Sci, Lunat Asylum, Pasadena, CA 91125 USA. Nat Hist Museum, Dept Mineral, London SW7 5BD, England. NIST, Analyt Microscopy Grp, College Pk, MD 20742 USA. RP Russell, SS (reprint author), CALTECH, Dept Geol & Planetary Sci, Lunat Asylum, Pasadena, CA 91125 USA. RI WASSERBURG, GERALD /F-6247-2011; Fahey, Albert/C-5611-2015 NR 107 TC 108 Z9 111 U1 5 U2 21 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD FEB PY 1998 VL 62 IS 4 BP 689 EP 714 DI 10.1016/S0016-7037(97)00374-8 PG 26 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZH971 UT WOS:000073166700011 ER PT J AU van Dam, TM Francis, O AF van Dam, TM Francis, O TI Two years of continuous measurements of tidal and nontidal variations of gravity in Boulder, Colorado SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OCEAN TIDES; DEFORMATION AB We report here on the results of an analysis of 2 years of data from NOAA's superconducting gravimeter located at the Table Mountain Gravity Observatory in Boulder, Colorado. Observed tidal parameters, corrected for ocean loading effects, are compared with theoretical tidal parameters predicted for a non-hydrostatic inelastic Earth model and demonstrate excellent agreement. Tidal residuals, corrected for polar motion and a linear instrument drift are highly correlated with gravity changes measured by two absolute gravimeters over the same time period. The admittance to local pressure is found to be -0.356 mu Gal/mbar. However, this admittance factor is found to be seasonally and frequency dependent. Correlations between rainfall events and gravity changes are observed. Attempts to model these gravity changes as exponential functions of time were unsuccessful. C1 Univ Colorado, NOAA, NGS, Boulder, CO 80309 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. Observ Royal Belgique, B-1180 Brussels, Belgium. RP van Dam, TM (reprint author), Univ Colorado, NOAA, NGS, Boulder, CO 80309 USA. NR 21 TC 29 Z9 29 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 1 PY 1998 VL 25 IS 3 BP 393 EP 396 DI 10.1029/97GL03780 PG 4 WC Geosciences, Multidisciplinary SC Geology GA YV640 UT WOS:000071848000043 ER PT J AU Godo, OR Karp, WA Totland, A AF Godo, OR Karp, WA Totland, A TI Effects of trawl sampling variability on precision of acoustic abundance estimates of gadoids from the Barents Sea and the Gulf of Alaska SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE trawl sampling variability; acoustic estimates; gadoids; resampling ID INDEXES; DENSITY AB The quality of acoustic estimates of fish abundance is dependent on the quality of the biological information that provides the basis for determining target size, species composition and acoustic target strength distribution. Information on biological characteristics of acoustic targets is usually obtained from trawl samples. In this paper we analyse the effects of trawl sampling variability on estimates of gadoid stock abundance in two areas where behavioural characteristics of the target species differ. The analyses demonstrate the sensitivity of abundance estimates to trawl sampling. Improved procedures for allocation of trawl sample information to acoustic survey results are discussed. C1 Inst Marine Res, N-5024 Bergen, Norway. Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Godo, OR (reprint author), Inst Marine Res, POB 1870, N-5024 Bergen, Norway. OI Godo, Olav Rune/0000-0001-8826-8068 NR 15 TC 12 Z9 12 U1 1 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD FEB PY 1998 VL 55 IS 1 BP 86 EP 94 DI 10.1006/jmsc.1997.0255 PG 9 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA ZD487 UT WOS:000072690900007 ER PT J AU Mileti, G Deng, JQ Walls, FL Jennings, DA Drullinger, RE AF Mileti, G Deng, JQ Walls, FL Jennings, DA Drullinger, RE TI Laser-pumped rubidium frequency standards: New analysis and progress SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE laser optically pumping; Rb frequency standard ID SEMICONDUCTOR-LASER; ATOMIC CLOCK; STABILITY AB We have achieved a stability of 3 . 10(-13) tau(-1/2) for 3 < tau < 30 s with a laser-pumped rubidium gas-cell frequency standard by reducing the effects due to noise in the microwave and laser sources, This result is one order of magnitude better than the best present performance of lamp-pumped devices. C1 Observ Cantonal Neuchatel, CH-2000 Neuchatel, Switzerland. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Mileti, G (reprint author), Observ Cantonal Neuchatel, CH-2000 Neuchatel, Switzerland. NR 27 TC 80 Z9 84 U1 4 U2 13 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD FEB PY 1998 VL 34 IS 2 BP 233 EP 237 DI 10.1109/3.658700 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA YT637 UT WOS:000071627000003 ER PT J AU Stenbakken, GN Deyst, JP AF Stenbakken, GN Deyst, JP TI Comparison of time base nonlinearity measurement techniques SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article; Proceedings Paper CT IEEE Instrumentation and Measurement Technology Conference - Sensing, Processing, Networking (IMTC/97) CY MAY 18-22, 1997 CL OTTAWA, CANADA SP IEEE Instrumentat & Measurement Soc, IEEE Ottawa Sect DE analytic signal; digitizer; distortion; measurement; multiphase; nonlinear; simulation; sinefit; time base ID DIGITIZER AB Distortions in the timebases of equivalent-time oscilloscopes and digitizers cause distortions of waveforms sampled by them. This paper reports on a comparison of two methods of characterizing timebase distortion, using pure sine-wave inputs of known frequency: the "sinefit" and the "analytic signal" methods. Simulations are used to compare the performance of the two methods versus different types of timebase distortion, different sine-wave frequencies, number of different sine-wave phases, levels of random noise, and levels of random jitter, The performance of the two methods varies considerably, dependent upon the input signal frequency and type of timebase distortion. Each method does much better than the other for certain cases. C1 US Dept Commerce, Technol Adm, US Natl Inst Stand & TEchnol, Div Elect, Gaithersburg, MD 20899 USA. RP Stenbakken, GN (reprint author), US Dept Commerce, Technol Adm, US Natl Inst Stand & TEchnol, Div Elect, Gaithersburg, MD 20899 USA. NR 17 TC 17 Z9 19 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD FEB PY 1998 VL 47 IS 1 BP 34 EP 39 DI 10.1109/19.728785 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 136CZ UT WOS:000076841900008 ER PT J AU Avramov-Zamurovic, S Oldham, NM Parker, ME Waltrip, BC AF Avramov-Zamurovic, S Oldham, NM Parker, ME Waltrip, BC TI Low-frequency characteristics of thin-film multijunction thermal voltage converters SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article; Proceedings Paper CT IEEE Instrumentation and Measurement Technology Conference - Sensing, Processing, Networking (IMTC/97) CY MAY 18-22, 1997 CL OTTAWA, CANADA SP IEEE Instrumentat & Measurement Soc, IEEE Ottawa Sect DE AC-DC power conversion; error analysis; frequency domain analysis; nonlinear systems; thermal converters; thin-film circuit thermal factors; thin-film circuits; transfer functions AB Low-frequency errors of thin-film multijunction thermal voltage converters are estimated using a simple model based on easily measured parameters. The model predictions are verified by measuring the converter's frequency characteristic using a digitally synthesized source. C1 USN Acad, Weap & Syst Engn Dept, Annapolis, MD 21402 USA. Natl Inst Stand & Technol, Div Elect, Gaithersburg, MD 20899 USA. RP Avramov-Zamurovic, S (reprint author), USN Acad, Weap & Syst Engn Dept, Annapolis, MD 21402 USA. NR 5 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD FEB PY 1998 VL 47 IS 1 BP 87 EP 89 DI 10.1109/19.728796 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 136CZ UT WOS:000076841900019 ER PT J AU Coombs, D Herman, M Hong, TH Nashman, M AF Coombs, D Herman, M Hong, TH Nashman, M TI Real-time obstacle avoidance using central flow divergence, and peripheral flow SO IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION LA English DT Article DE active vision; digital control; feedback systems; image motion analysis; mobile robots; mobile robot motion planning; object identification; real time systems; recursive estimation; robot vision systems ID VISION AB The lure of using motion vision as a fundamental element in the perception of space drives this effort to use dow features as the sole cues for robot mobility, Real-time estimates of image flow and flow divergence provide the robot's sense of space. The robot steers down a conceptual corridor, comparing left and right peripheral flows, Large central flow divergence warns the robot of impending collisions at "dead ends." When this occurs, the robot turns around and resumes wandering. Behavior is generated by directly using flow-based information in the two dimensional (2-D) image sequence; no three-dimensional (3-D) reconstruction is attempted. Active mechanical gaze stabilization simplifies the visual interpretation problems by reducing camera rotation. By combining corridor following and dead-end deflection, the robot has wandered around the lab at 30 cm/s for as long as 20 min without collision. The ability to support this behavior in real-time with current equipment promises expanded capabilities as computational power increases in the future. C1 Natl Inst Stand & Technol, Intelligent Syst Div, Gaithersburg, MD 20899 USA. RP Coombs, D (reprint author), Natl Inst Stand & Technol, Intelligent Syst Div, Gaithersburg, MD 20899 USA. NR 27 TC 51 Z9 53 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 1042-296X J9 IEEE T ROBOTIC AUTOM JI IEEE Trans. Robot. Autom. PD FEB PY 1998 VL 14 IS 1 BP 49 EP 59 DI 10.1109/70.660840 PG 11 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Engineering; Robotics GA YX401 UT WOS:000072036300004 ER PT J AU Pellegrino, J Kang, YS Tighe, J Portnoy, J AF Pellegrino, J Kang, YS Tighe, J Portnoy, J TI Effective medium conductivity (diffusivity) for a sphere in a cube model SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB A modified analytical solution for the effective medium conductivity (or diffusivity) k(eff) for two-phase mixtures yields estimates similar to 0.2 - 26 % lower than the classic model of a sphere in a cube (Jefferson et al. Ind. Eng. Chem. 1958, 50, 1589) depending on the ratios of phase conductivities and volumes. The difference between the two solutions lies in the assumption of an isothermal plane at the edge of the sphere in the original derivation. The temperature contours obtained with a finite element method simulation of the model confirm the intuitive judgement that this assumption is not valid. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Pellegrino, J (reprint author), Natl Inst Stand & Technol, 325 Broadway,838-01, Boulder, CO 80303 USA. OI PELLEGRINO, JOHN/0000-0001-7749-5003 NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD FEB PY 1998 VL 37 IS 2 BP 704 EP 706 DI 10.1021/ie970610g PG 3 WC Engineering, Chemical SC Engineering GA YV779 UT WOS:000071862500049 ER PT J AU Gass, SI Witzgall, C Harary, HH AF Gass, SI Witzgall, C Harary, HH TI Fitting circles and spheres to coordinate measuring machine data SO INTERNATIONAL JOURNAL OF FLEXIBLE MANUFACTURING SYSTEMS LA English DT Article DE Chebychev minmax; circle and sphere out-of-roundness tolerance; coordinate measuring machine; linear programming; quality control ID ALGORITHMS AB This work addresses the problem of enclosing given data points between two concentric circles (spheres) of minimum distance whose associated annulus measures the out-of-roundness (OOR) tolerance. The problem arises in analyzing coordinate measuring machine (CMM) data taken against circular (spherical) features of manufactured parts. It also can be interpreted as the "geometric" Chebychev problem of fitting a circle (sphere) to data so as to minimize the maximum distance deviation. A related formulation, the "algebraic" Chebychev formula, determines the equation of a circle (sphere) to minimize the maximum violation of the equation by the data points. In this paper, we describe a linear-programming approach for the algebraic Chebychev formula that determines reference circles (spheres) and related annuluses whose widths are very close to the widths of the true geometric Chebychev annuluses. We also compare the algebraic Chebychev formula against the popular algebraic least-squares solutions for various data sets. In most of these examples, the algebraic and geometric Chebychev solutions coincide, which appears to be the case for most real applications. Such solutions yield concentric circles whose separation is less than that of the corresponding least-squares solution. It is suggested that the linear-programming approach be considered as an alternate solution method for determining OOR annuluses for CMM data sets. C1 Univ Maryland, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Gaithersburg, MD USA. RP Gass, SI (reprint author), Univ Maryland, College Pk, MD 20742 USA. NR 27 TC 18 Z9 18 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0920-6299 J9 INT J FLEX MANUF SYS JI Int. J. Flexible Manuf. Syst. PD FEB PY 1998 VL 10 IS 1 BP 5 EP 25 DI 10.1023/A:1007996916604 PG 21 WC Engineering, Manufacturing; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA ZL870 UT WOS:000073481800001 ER PT J AU Kubo, HD Coursey, BM Hanson, WF Kline, RW Seltzer, SM Shuping, RE Williamson, JF AF Kubo, HD Coursey, BM Hanson, WF Kline, RW Seltzer, SM Shuping, RE Williamson, JF TI Report of the ad hoc committee of the AAPM radiation therapy committee on I-125 sealed source dosimetry SO INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS LA English DT Article DE I-125 dosimetry; brachytherapy; dose-rate constant ID I125 SEEDS; WATER AB Purpose: Two developments in I-125-sealed source dosimetry have necessitated swift and accurate implementation of TG-43 dosimetry in clinic: (a) the dosimetry constants of I-125 endorsed by the AAPM Task Group 43 Report result in calculated dose rate that deviates by as much as 15 % from currently accepted dose-rate distributions, and (b) The National Institute of Standards and Technology (NIST) has proposed modifying the I-125 air-kerma strength standard by approximately 10 %. Methods and Materials: The ad hoc committee of AAPM Radiation Therapy Committee describes specific procedures to implement these two developments without causing confusion and mistakes. Conclusions: Confusion and mistakes may be avoided when the following two general steps are taken: 1) STEP L, TG-43 implementation, and 2) STEP II, new air-kerma strength standard implementation when available from NIST. (C) 1998 Elsevier Science Inc. C1 Univ Calif Davis, Ctr Canc, Dept Radiat Oncol, Sacramento, CA 95817 USA. Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD USA. Univ Texas, Md Anderson Canc Ctr, Dept Radiat Phys, Houston, TX 77030 USA. Mayo Clin, Dept Radiat Oncol, Rochester, MN USA. Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. US FDA, Rockville, MD 20857 USA. Washington Univ, Mallinckrodt Inst Radiol, St Louis, MO USA. RP Kubo, HD (reprint author), Univ Calif Davis, Ctr Canc, Dept Radiat Oncol, Ste G-126,4501 X St, Sacramento, CA 95817 USA. NR 12 TC 32 Z9 32 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0360-3016 J9 INT J RADIAT ONCOL JI Int. J. Radiat. Oncol. Biol. Phys. PD FEB 1 PY 1998 VL 40 IS 3 BP 697 EP 702 DI 10.1016/S0360-3016(97)00767-0 PG 6 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA YX786 UT WOS:000072077700024 PM 9486622 ER PT J AU Gallo, KP Huang, A AF Gallo, KP Huang, A TI Evaluation of the NDVI and sensor zenith angle values associated with the Global Land AVHRR 1-km data set SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article AB This study was initiated to assess the quality of the data available from the Global Land AVHRR l-km data set. The normalized difference vegetation index (NDVI) and sensor zenith angle (SZ) values associated with the Global Land AVHRR l-km data set were compared to those values included in the NOAA/NASA Pathfinder AVHRR Land (global, 8-km) data set at coincident spatial and temporal scales. The NDVI and SZ data were averaged within 10 degrees by 10 degrees grid cells and compared for each of the 10-day composite intervals during the 1 April 1992 through 31 March 1993 time period. The results indicate that the sensor zenith angles of the two data sets varied considerably, however, the NDVI values were quite similar. C1 NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Washington, DC 20233 USA. Univ N Carolina, Dept Atmospher Sci, Asheville, NC 28804 USA. RP Gallo, KP (reprint author), Natl Climat Data Ctr, Asheville, NC 28801 USA. RI Gallo, Kevin P./F-5588-2010 NR 6 TC 6 Z9 6 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD FEB PY 1998 VL 19 IS 3 BP 527 EP 533 DI 10.1080/014311698216143 PG 7 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA ZA283 UT WOS:000072348000012 ER PT J AU Ryzhkov, AV Zrnic, DS Gordon, BA AF Ryzhkov, AV Zrnic, DS Gordon, BA TI Polarimetric method for ice water content determination SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID RADAR REFLECTIVITY; CLOUDS; PARTICLES; MASSES AB Two variants of a polarimetric method to determine ice water content are presented. One uses specific differential phase and differential reflectivity and the other uses specific differential phase; both quantities are for a IO-cm wavelength. Theoretical considerations indicate that these polarimetric methods are suited for pristine ice crystals. Ice water content of lightly to moderately aggregated crystals might also be estimated. Verification of the proposed method is made using in situ data collected by the T-28 instrumented aircraft. Comparison with two estimators that use the reflectivity factor suggests that the polarimetric methods are better and can quantify correctly ice water content in the range above 0.1 g m(-3). C1 Natl Severe Storms Lab, CIMMS, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP Ryzhkov, AV (reprint author), Natl Severe Storms Lab, CIMMS, 1313 Halley Circle, Norman, OK 73069 USA. NR 24 TC 43 Z9 43 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD FEB PY 1998 VL 37 IS 2 BP 125 EP 134 DI 10.1175/1520-0450(1998)037<0125:PMFIWC>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YW748 UT WOS:000071969300001 ER PT J AU Eckman, RM AF Eckman, RM TI Observations and numerical simulations of winds within a broad forested valley SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MOUNTAINS; BREEZES; FLOW AB The Tennessee River Valley in the eastern part of Tennessee is a broad valley with a moist climate and extensive forest cover. A series of 50-100-m-high parallel ridges forms corrugations along the floor of the valley. Tower measurements and numerical simulations are used in this paper to study the channeling of the winds in this valley over the diurnal cycle. At night, pressure-driven channeling caused by geostrophic imbalances is often present, but this channeling tends to be concentrated on the leeward side of the valley (relative to the winds aloft). The channeling is significantly weaker during the afternoon, so the winds on top of the corrugations are more closely aligned with those aloft. In the bottomlands between the corrugations, however, the daytime winds are more effectively channeled parallel to the valley axis. Although thermally driven winds are not dominant in the Tennessee Valley, a discernible pattern of upvalley daytime winds and downvalley nighttime winds is observed in the tower measurements. Nighttime drainage Rows are particularly evident in the bottomlands between the corrugations. Climatologically, the transition from typical nighttime to typical daytime Row conditions occurs around 0900-1100 LST, and the transition back to nighttime conditions occurs around 1700-1900 LST. Separate sets of numerical simulations were performed for typical summer and winter conditions. These sets differed in their temperature and humidity profiles, surface vegetation characteristics, and soil water. Little systematic difference is observed in the two sets of simulations, suggesting that seasonal variations in surface properties play a relatively minor role in the observed channeling. Overall, the wind channeling can be explained by individually considering the flow deflections caused by the mountain ranges on each side of the valley. Each of these ranges can produce leftward deflections of the oncoming flow depending on its bulk Rossby and Froude numbers. The two ranges appear to interact in that the range on the windward side of the valley tends to reduce the Rossby and Froude numbers of the leeward range, thus allowing the leeward range to be more effective in deflecting the oncoming flow. C1 Natl Ocean & Atmospher Adm, Atmospher Turbulence & Diffus Div, Air Resources Lab, Oak Ridge, TN 37831 USA. RP Eckman, RM (reprint author), Natl Ocean & Atmospher Adm, Atmospher Turbulence & Diffus Div, Air Resources Lab, POB 2456, Oak Ridge, TN 37831 USA. RI Eckman, Richard/D-1476-2016 NR 18 TC 15 Z9 15 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD FEB PY 1998 VL 37 IS 2 BP 206 EP 219 DI 10.1175/1520-0450(1998)037<0206:OANSOW>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YW748 UT WOS:000071969300006 ER PT J AU Achcar, JA Agrawal, MC Anand, KN Ali, MM Ali, MM Bagui, SC Baker, RD Balamurali, S Balasooriya, U Bansal, AK Barry, J Bonett, DG Box, G Carling, K Caudill, SB Chakraborti, S Chatfield, C Chatterjee, S Cornell, JA Cox, D Draper, NR Ehrenberg, A Finney, DJ Franses, PH Fung, WK Gani, JM Ghatak, A Gibbings, JC Godtliebsen, F Gore, AP Govindarajulu, Z Granger, CWJ Guerrero, VM Hand, DJ Hawkes, AG Hinkelmann, K Huda, S Irmay, S Jeffers, JNR Kaboudan, MA Kacker, R Kalirajan, KP Kenett, RS Khamis, HJ Khuri, AI Kocherlakota, S Kotz, S Kumar, VSS Lewis, T Lindley, D Mardia, KV McAleer, M McLachlan, G Moore, PG Naik, DN Oliver, FR Park, SH Pearce, SC Percy, DF Prescott, P Quesenberry, C Radaelli, G Raju, C Schoen, ED Seber, G Shoukri, M Silver, M Singh, M Soundararajan, V Suresh, KK Stonehouse, J Tomizawa, S Vijayaraghavan, R Wang, DL Watson, GS Wagman, EJ Wenmoth, BA Wichern, DW Wynn, HP Zellner, A Zhang, NF AF Achcar, JA Agrawal, MC Anand, KN Ali, MM Ali, MM Bagui, SC Baker, RD Balamurali, S Balasooriya, U Bansal, AK Barry, J Bonett, DG Box, G Carling, K Caudill, SB Chakraborti, S Chatfield, C Chatterjee, S Cornell, JA Cox, D Draper, NR Ehrenberg, A Finney, DJ Franses, PH Fung, WK Gani, JM Ghatak, A Gibbings, JC Godtliebsen, F Gore, AP Govindarajulu, Z Granger, CWJ Guerrero, VM Hand, DJ Hawkes, AG Hinkelmann, K Huda, S Irmay, S Jeffers, JNR Kaboudan, MA Kacker, R Kalirajan, KP Kenett, RS Khamis, HJ Khuri, AI Kocherlakota, S Kotz, S Kumar, VSS Lewis, T Lindley, D Mardia, KV McAleer, M McLachlan, G Moore, PG Naik, DN Oliver, FR Park, SH Pearce, SC Percy, DF Prescott, P Quesenberry, C Radaelli, G Raju, C Schoen, ED Seber, G Shoukri, M Silver, M Singh, M Soundararajan, V Suresh, KK Stonehouse, J Tomizawa, S Vijayaraghavan, R Wang, DL Watson, GS Wagman, EJ Wenmoth, BA Wichern, DW Wynn, HP Zellner, A Zhang, NF TI 25 years of applied statistics SO JOURNAL OF APPLIED STATISTICS LA English DT Editorial Material C1 Univ Sao Paulo, Sao Paulo, Brazil. Univ Delhi, Delhi 110007, India. Indian Stat Inst, Calcutta, W Bengal, India. Ball State Univ, Muncie, IN 47306 USA. Univ Kentucky, Lexington, KY 40506 USA. Univ W Florida, Pensacola, FL 32514 USA. Univ Salford, Salford M5 4WT, Lancs, England. Bharathiar Univ, Coimbatore, Tamil Nadu, India. Mem Univ Newfoundland, St Johns, NF A1C 5S7, Canada. Univ Lancaster, Lancaster LA1 4YW, England. Univ Wyoming, Laramie, WY 82071 USA. Univ Wisconsin, Madison, WI 53706 USA. Univ Uppsala, S-75105 Uppsala, Sweden. Auburn Univ, Auburn, AL 36849 USA. Univ Alabama, Tuscaloosa, AL 35487 USA. Univ Bath, Bath BA2 7AY, Avon, England. Northeastern Univ, Boston, MA USA. Univ Florida, Gainesville, FL 32611 USA. Univ Oxford Nuffield Coll, Oxford OX1 1NF, England. S Bank Univ, London SE1 0AA, England. Rotterdam Inst Business Econ Studies, Rotterdam, Netherlands. Chinese Univ Hong Kong, Sha Tin 100083, Hong Kong. Australian Natl Univ, Canberra, ACT, Australia. De Montfort Univ, Leicester LE1 9BH, Leics, England. Univ Tromso, N-9001 Tromso, Norway. Univ Poona, Poona 411007, Maharashtra, India. Open Univ, Milton Keynes, Bucks, England. Univ Wales, Cardiff CF1 3NS, S Glam, Wales. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. King Saud Univ, Riyadh, Saudi Arabia. Israel Inst Technol, Haifa, Israel. Penn State Univ, University Pk, PA 16802 USA. Natl Inst Stand & Technol, Washington, DC USA. Tel Aviv Univ, IL-69978 Tel Aviv, Israel. Wright State Univ, Dayton, OH 45435 USA. Univ Florida, Gainesville, FL 32611 USA. Univ Manitoba, Winnipeg, MB R3T 2N2, Canada. Univ Maryland, College Pk, MD 20742 USA. Manonmamiam Sundaranar Univ, Palayankottai, India. Univ E Anglia, Norwich NR4 7TJ, Norfolk, England. Univ Leeds, Leeds LS2 9JT, W Yorkshire, England. Univ Queensland, St Lucia, Qld 4067, Australia. London Business Sch, London, England. Old Dominion Univ, Norfolk, VA 23529 USA. Univ Exeter, Exeter EX4 4QJ, Devon, England. Univ Kent, Canterbury, Kent, England. Univ Salford, Salford M5 4WT, Lancs, England. Univ Southampton, Southampton SO9 5NH, Hants, England. Univ Milan, I-20122 Milan, Italy. Univ Mysore, Mysore 570005, Karnataka, India. TNO, Inst Phys Appl, The Hague, Netherlands. Univ Auckland, Auckland 1, New Zealand. Univ Guelph, Guelph, ON N1G 2W1, Canada. Cardiff Business Sch, Cardiff, S Glam, Wales. ICARDA, Aleppo, Syria. Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England. Sci Univ Japan, Tokyo, Japan. Univ London London Sch Econ & Polit Sci, London WC2A 2AE, England. Princeton Univ, Princeton, NJ 08544 USA. George Mason Univ, Fairfax, VA 22030 USA. Texas A&M Univ, College Stn, TX 77843 USA. Univ Warwick, Coventry CV4 7AL, W Midlands, England. Univ Chicago, Chicago, IL 60637 USA. RI McAleer, Michael/A-2407-2008; Franses, Philip Hans/D-4398-2009; McAleer, Michael/B-2978-2010; McLachlan, Geoffrey/A-1491-2008 OI McLachlan, Geoffrey/0000-0002-5921-3145 NR 0 TC 0 Z9 0 U1 0 U2 10 PU CARFAX PUBL CO PI ABINGDON PA PO BOX 25, ABINGDON, OXFORDSHIRE, ENGLAND OX14 3UE SN 0266-4763 J9 J APPL STAT JI J. Appl. Stat. PD FEB PY 1998 VL 25 IS 1 BP 3 EP 22 PG 20 WC Statistics & Probability SC Mathematics GA ZH970 UT WOS:000073166600001 ER PT J AU Collins, WG AF Collins, WG TI Complex quality control of significant level rawinsonde temperatures SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article; Proceedings Paper CT 9th Symposium on Meteorological Observations and Instrumentation CY MAR 27-31, 1995 CL CHARLOTTE, NORTH CAROLINA SP Amer Meteorol Soc ID NATIONAL-METEOROLOGICAL-CENTER AB Rawinsonde heights and temperatures have been quality controlled using complex quality control at the National Centers for Atmospheric Prediction since December 1988 when an algorithm using only hydrostatic checking was introduced for the checking of mandatory level heights and temperatures. The quality control of significant level temperatures was added to the hydrostatic code in April 1990. In November 1991, the mandatory level checking was greatly expanded and improved by the inclusion of additional checks: increment (observation minus 6-h forecast), horizontal, and vertical. This paper describes a major improvement to the significant level quality control, introduced in May 1994, using complex quality control techniques. The philosophy of the method and the various checks are described. The principles of the decision-making algorithm are stated, examples are shown, and some statistics of the use of the significant level checking are presented. C1 NOAA, Natl Weather Serv, NCEP, Washington, DC 20233 USA. RP Collins, WG (reprint author), NOAA, Natl Weather Serv, NCEP, W-NP22-WC,Room 207, Washington, DC 20233 USA. NR 7 TC 4 Z9 5 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD FEB PY 1998 VL 15 IS 1 BP 69 EP 79 DI 10.1175/1520-0426(1998)015<0069:CQCOSL>2.0.CO;2 PN 1 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA YV252 UT WOS:000071804600008 ER PT J AU Matrosov, SY Heymsfield, AJ Kropfli, RA Martner, BE Reinking, RF Snider, JB Piironen, P Eloranta, EW AF Matrosov, SY Heymsfield, AJ Kropfli, RA Martner, BE Reinking, RF Snider, JB Piironen, P Eloranta, EW TI Comparisons of ice cloud parameters obtained by combined remote sensor retrievals and direct methods SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID INFRARED RADIOMETER; RADAR MEASUREMENTS; CIRRUS; SIZES AB Ice cloud microphysical parameters derived from a remote sensing method that uses ground-based measurements from the Environmental Technology Laboratory's K-a-band radar and an IR radiometer are compared to those obtained from aircraft sampling for the cirrus priority event from the FIRE-II experiment. Aircraft cloud samples were taken not only by traditional two-dimensional probes but also by using a new video sampler to account for small particles. The cloud parameter comparisons were made for time intervals when aircraft were passing approximately above ground-based instruments that were pointed vertically. Comparing characteristic particle sizes expressed in terms of median mass diameters of equal-volume spheres yielded a relative standard deviation of about 30%. The corresponding standard deviation for the cloud ice water content comparisons was about 55%. Such an agreement is considered good given uncertainties of both direct and remote approaches and several orders of magnitude in natural variability of ice cloud parameters. Values of reflectivity measured by the radar and calculated from aircraft samples also showed a reasonable agreement; however, calculated reflectivities averaged approximately 2 dB smaller than those measured. The possible reasons for this small bias are discussed. Ground-based and aircraft-derived particle characteristic sizes are compared to those available from published satellite measurements of this Parameter for the cirrus priority case from FIRE-II. Finally, simultaneous and collocated, ground-based measurements of visible (0.523 nm) and longwave IR (10-11.4 mu m) ice cloud extinction optical thickness obtained during the 1995 Arizona Program are also compared. These comparisons, performed for different cloud conditions, revealed a relative standard deviation of less than 20%; however, no systematic excess of visible extinction over LR extinction was observed in the considered experimental events. C1 Univ Colorado, Cooperat Inst Res Environm Sci, NOAA, Boulder, CO 80309 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Wisconsin, Madison, WI USA. RP Matrosov, SY (reprint author), NOAA, Environm Res Lab, ETL, R-E-ET6,325 Broadway, Boulder, CO 80303 USA. EM smatrosov@etl.noaa.gov RI Heymsfield, Andrew/E-7340-2011 NR 28 TC 20 Z9 21 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD FEB PY 1998 VL 15 IS 1 BP 184 EP 196 DI 10.1175/1520-0426(1998)015<0184:COICPO>2.0.CO;2 PN 1 PG 13 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA YV252 UT WOS:000071804600018 ER PT J AU Reddy, P Kamireddi, M AF Reddy, P Kamireddi, M TI Modulation of Escherichia coli adenylyl cyclase activity by catalytic-site mutants of protein IIA(Glc) of the phosphoenolpyruvate : sugar phosphotransferase system SO JOURNAL OF BACTERIOLOGY LA English DT Article ID SALMONELLA-TYPHIMURIUM; PHOSPHOCARRIER PROTEIN; DIRECTED MUTAGENESIS; GENE-PRODUCTS; IIIGLC AB It is demonstrated here that in Escherichia coli, the phosphorylated form of the glucose-specific phosphocarrier protein IIA(Glc) of the phosphoenolpyruvate:sugar phosphotransferase system is an activator of adenylyl cyclase and that unphosphorylated IIA(Glc) has no effect on the basal activity of adenylyl cyclase, To elucidate the specific role of IIA(Glc) phosphorylation in the regulation of adenylyl cyclase activity, both the phosphorylatable histidine (H90) and the interactive histidine (H75) of IIA(Glc) were mutated by site-directed mutagenesis to glutamine and glutamate, Wild-type IIA(Glc) and the H75Q mutant, in which the histidine in position 75 has been replaced by glutamine, were phosphorylated by the phosphohistidine-containing phosphocarrier protein (HPr similar to P) and were equally potent activators of adenylyl cyclase, Neither the H90Q nor the H90E mutant of IIA(Glc) was phosphorylated by HPr similar to P, and both failed to activate adenylyl cyclase. Furthermore, replacement of H75 bg glutamate inhibited the appearance of a steady-state level of phosphorylation of H90 of this mutant protein by HPr similar to P, vet the H75E mutant of IIA(Glc) was a partial activator of adenylyl cyclase. The H75E H90A double mutant, which cannot be phosphorylated, did not activate adenylyl cyclase. This suggests that the H75E mutant was transiently phosphorylated by HPr similar to P but the steady-state level of the phosphorylated form of the mutant protein was decreased due to the repulsive forces of the negatively charged glutamate at position 75 in the catalytic pocket. These results are discussed in the context of the proximity of H75 and H90 in the IIA(Glc) structure and the disposition of the negative charge in the modeled glutamate mutants. C1 NIST, DNA Technol Grp, Div Biotechnol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Reddy, P (reprint author), NIST, DNA Technol Grp, Div Biotechnol, Chem Sci & Technol Lab, Bldg 222,Room A359, Gaithersburg, MD 20899 USA. NR 31 TC 25 Z9 25 U1 0 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD FEB PY 1998 VL 180 IS 3 BP 732 EP 736 PG 5 WC Microbiology SC Microbiology GA YU722 UT WOS:000071747700039 PM 9457881 ER PT J AU Lindner, J Loomis, RA Klaassen, JJ Leone, SR AF Lindner, J Loomis, RA Klaassen, JJ Leone, SR TI A laser photolysis time-resolved Fourier transform infrared emission study of OH(X (2)Pi, v) produced in the reaction of alkyl radicals with O(P-3) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIPOLE-MOMENT FUNCTION; 193 NM; STATE DISTRIBUTION; RATE COEFFICIENTS; FLASH-PHOTOLYSIS; MOLECULAR-BEAMS; FTIR EMISSION; PHOTODISSOCIATION; SO2; SPECTROSCOPY AB The emission spectra of vibrationally excited hydroxyl radical products formed in the reactions of alkyl radicals with O(P-3) atoms are detected using a laser photolysis/time-resolved Fourier transform infrared spectroscopy technique. For the reaction between oxygen atoms and ethyl, the radicals are produced simultaneously by the 193 nm photolysis of the precursors SO2 and diethyl ketone, respectively. The observed initial OH(upsilon) product vibrational state distribution for the C2H5 + O(P-3) reaction is 0.18 +/- 0.03, 0.23 +/- 0.04, 0.29 +/- 0.05, 0.23 +/- 0.07, and 0.07 +/- 0.04 for upsilon = 1 to 5, respectively. The population inversion is best explained by a direct abstraction mechanism for this radical-radical reaction. Vibrationally excited hydroxyl radicals are also observed in the O + ethyl, O + n-propyl, and O + i-propyl reactions when using alkyl iodides as precursors of the alkyl radicals, although quantitative detail is not obtained due to competing reaction processes. (C) 1998 American Institute of Physics. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Lindner, J (reprint author), Univ Hannover, Inst Quantenopt, Welfengarten 1, D-30167 Hannover, Germany. NR 45 TC 39 Z9 39 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 1 PY 1998 VL 108 IS 5 BP 1944 EP 1952 DI 10.1063/1.475575 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YU725 UT WOS:000071748000025 ER PT J AU Peterson, JR Le Padellec, A Danared, H Dunn, GH Larsson, M Larson, A Peverall, R Stromholm, C Rosen, S af Ugglas, M van der Zande, WJ AF Peterson, JR Le Padellec, A Danared, H Dunn, GH Larsson, M Larson, A Peverall, R Stromholm, C Rosen, S af Ugglas, M van der Zande, WJ TI Dissociative recombination and excitation of N-2(+): Cross sections and product branching ratios SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID STATE DISTRIBUTIONS; RATE COEFFICIENT; MOLECULAR-IONS; (HEH+)-HE-4; MECHANISMS; ELECTRONS; NITROGEN; ESCAPE; VENUS; MARS AB The absolute dissociative recombination and absolute dissociative excitation rate coefficients and cross sections have been determined for N-2(+) and electrons for collision energies between 10 meV and 30 eV. The ion storage ring CRYRING has been used in combination with an imaging technique with a position-and-time-sensitive detector. Information is retrieved on the ion beam vibrational state populations and on the product branching in the dissociative recombination process at 0 eV collisions. A hollow cathode ion source has been used to lower the vibrational excitation in the ion beam; a more traditional hot-cathode ion source was used as well. The most important findings are the following. The rate coefficient for an N-2(+) ion beam (46%, upsilon = 0, 27% upsilon = 1) versus electron temperature (K) is alpha(T-e) = 1.75(+/-0.09) x 10(-7)(T-e/300)(-0.30) cm(3) s(-1). The dissociative recombination rate is found to be weakly dependent on the N-2(+) vibrational level. At 0 eV collision energy, the upsilon = 0 product branching is found to be 0.37(8):0.11(6):0.52(4) for N(S-4) + N(D-2):N(P-2) + N(S-4) + N(D-2) + N(D-2) fragments. The dissociative recombination cross section does not have a high-energy peak as was found in a number of lighter molecular systems. The dissociative excitation signal starts only slightly above the energy threshold for dissociation, and peaks near 25 eV. From the dissociative excitation data and literature data, information is retrieved on the dissociative ionization of N-2(+). The comparison of these results with earlier DR measurements is extensively discussed. (C) 1998 American Institute of Physics. C1 SRI Int, Mol Phys Lab, Menlo Park, CA 94025 USA. Royal Inst Technol, Dept Phys, S-10044 Stockholm, Sweden. Univ Stockholm, Manne Siegbahn Lab, S-10405 Stockholm, Sweden. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Stockholm, Dept Phys, S-11385 Stockholm, Sweden. FOM, Inst Atom & Mol Phys, NL-1098 SJ Amsterdam, Netherlands. RP Peterson, JR (reprint author), SRI Int, Mol Phys Lab, Menlo Park, CA 94025 USA. OI Peverall, Robert/0000-0003-2326-2495 NR 61 TC 129 Z9 129 U1 1 U2 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 1 PY 1998 VL 108 IS 5 BP 1978 EP 1988 DI 10.1063/1.475577 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YU725 UT WOS:000071748000028 ER PT J AU Xie, PP Arkin, PA AF Xie, PP Arkin, PA TI Global monthly precipitation estimates from satellite-observed outgoing longwave radiation SO JOURNAL OF CLIMATE LA English DT Article ID TERM CLIMATE VARIABILITY; 40-50 DAY OSCILLATION; ATMOSPHERIC TELECONNECTIONS; INTERANNUAL VARIATIONS; NORTHERN WINTER; RAINFALL; SUMMER; CLOUD; CIRCULATION; HEMISPHERE AB The relationship between the flux of outgoing longwave radiation (OLR) estimated from satellite observations and precipitation is investigated using monthly OLR data from the NOAA polar-orbiting satellites and the merged analysis of precipitation of Xie and Arkin for the 8-yr period from July 1987 to June 1995. The mean annual cycle of OLR in the Tropics is dominated by changes in cloudiness and exhibits a strong negative correlation with precipitation, while in the extratropics the strongest influence on the annual cycle of OLR is surface temperature and a positive correlation with precipitation is found. However, the anomaly of OLR exhibits a negative correlation with precipitation over most of the globe. The regression coefficient relating the anomaly of precipitation to that of OLR is spatially inhomogeneous and seasonally dependent but can be expressed with high accuracy as a globally uniform linear function of the local mean precipitation. Based on these results, a new technique is developed to estimate monthly precipitation over the globe from OLR data. First, the mean annual cycle of precipitation is calculated from the merged analysis of precipitation for the 8-yr period. The precipitation anomaly is then estimated from the OLR anomaly field using the coefficient value appropriate for the mean annual cycle of precipitation at each location. Finally, the total precipitation is estimated as the sum of the mean annual cycle and the anomaly. Verification tests showed that this estimate, which is referred to here as the OLR-based precipitation index (OPI), is able to represent large-scale precipitation with globally uniform and temporally stable high quality? similar to geostationary satellite IR-based estimates over the Tropics and to estimates based on microwave scattering observations over extratropical areas. The OPI estimates are then produced for the 22-yr period from 1974 to 1995 and are used to investigate the annual and interannual variability of global precipitation. The mean distribution and seasonal variations as observed in the 22-yr set of OPI estimates agree well with those of several published long-term means of precipitation estimated from station observations, and the interannual variability in precipitation associated with the Fl Nino-Southern Oscillation phenomenon resemble those found in previous studies but with additional details, particularly over ocean areas. C1 NOAA, Natl Weather Serv, Natl Ctr Environm Predict, Washington, DC 20233 USA. RP Xie, PP (reprint author), NOAA, Natl Weather Serv, Natl Ctr Environm Predict, 800A, Washington, DC 20233 USA. EM xping@sgi17.wwb.noaa.gov RI Arkin, Phillip/F-5808-2010 NR 50 TC 160 Z9 165 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD FEB PY 1998 VL 11 IS 2 BP 137 EP 164 DI 10.1175/1520-0442(1998)011<0137:GMPEFS>2.0.CO;2 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YY523 UT WOS:000072156100003 ER PT J AU Wallis, TWR AF Wallis, TWR TI A subset of core stations from the Comprehensive Aerological Reference Dataset (CARDS) SO JOURNAL OF CLIMATE LA English DT Article ID TEMPERATURE AB The Comprehensive Aerological Reference Data Set (CARDS) is a database of radiosonde records from worldwide sources. However, many of the records are short or incomplete, and there are clear spatial distribution deficiencies. The objective of this investigation is to select a subset of core stations, with data that give the best possible temporal and spatial coverage for studies of atmospheric temperature or water vapor trends. This is accomplished by assessing the records for content, and calculating the areas for which stations are representative, from ECMWF gridpoint analysis correlation decay. A subset of 188 core stations is chosen. Their records still contain some periods of missing data; leave some of the earth's surface unrepresented, mostly over the southern oceans; and may have quality or homogeneity deficiencies. However, coverage, as assessed from information currently stored in CARDS, has been optimized. C1 Orkand Corp, Natl Climat Data Ctr, Asheville, NC 28806 USA. RP Wallis, TWR (reprint author), Orkand Corp, Natl Climat Data Ctr, Fed Bldg,151 Patton Ave, Asheville, NC 28806 USA. NR 15 TC 25 Z9 25 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD FEB PY 1998 VL 11 IS 2 BP 272 EP 282 DI 10.1175/1520-0442(1998)011<0272:ASOCSF>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YY523 UT WOS:000072156100010 ER PT J AU Coriell, SR Chernov, AA Murray, BT McFadden, GB AF Coriell, SR Chernov, AA Murray, BT McFadden, GB TI Step bunching: generalized kinetics SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE morphological stability; step motion; anisotropic kinetics; shear flow ID MORPHOLOGICAL STABILITY; CRYSTAL-GROWTH; KDP CRYSTALS; VICINAL FACE; FLOW; SURFACES; INSTABILITY; ELECTROMIGRATION; DEPENDENCE; MACROSTEPS AB Our previous model of the effect of a parallel shear flow and anisotropic interface kinetics on the onset of (linear) instability during growth from a supersaturated solution is extended to allow for a kinetic coefficient which is a nonlinear function of the supersaturation and crystallographic orientation. The presence of impurities in the binary solution is also treated, although for typical impurity levels there is no explicit effect of impurities on morphological stability. As previously, a shear flow counter to the step motion enhances stability and a shear flow in the direction of the step motion promotes instability. Instability is enhanced when the kinetic coefficient increases rapidly with supersaturation. Specific calculations are carried out for parameters appropriate to the growth of ADP and KDP from solution. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Space Res Assoc, Huntsville, AL 35806 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35806 USA. RP Coriell, SR (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM coriell@nist.gov RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 57 TC 41 Z9 41 U1 0 U2 15 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 FEB PY 1998 VL 183 IS 4 BP 669 EP 682 DI 10.1016/S0022-0248(97)00489-2 PG 14 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA YV678 UT WOS:000071851800018 ER PT J AU Gosling, JT Riley, P McComas, DJ Pizzo, VJ AF Gosling, JT Riley, P McComas, DJ Pizzo, VJ TI Overexpanding coronal mass ejections at high heliographic latitudes: Observations and simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SPEED SOLAR-WIND; INTERACTION REGIONS; ULYSSES; SHOCK; DRIVEN AB Ulysses observations reveal that most coronal mass ejections (CMEs) observed in the solar wind far from the Sun at high heliographic latitudes have large radial widths and are still expanding as they pass the spacecraft. CME radial widths ranging between 0.5 and 2.5 AU have been observed at heliocentric distances between 1.4 and 4.6 AU and at latitudes greater than 22 degrees. A CME may expand simply because it is ejected from the Sun with a leading edge speed that is greater than its trailing edge speed. Rarefaction waves produced by relative motion between a CME and the surrounding wind also can cause a CME to expand. Finally, a CME may expand because it is ejected into the wind with an internal pressure that is greater than that of the surrounding wind. In the latter case, which we have called "overexpansion," the expansion tends to drive compressive waves into the surrounding solar wind; these waves commonly steepen into shocks at large distances from the Sun. The relative importance of these various expansion processes differs from event to event depending upon initial conditions within the CME and the surrounding wind. Using Ulysses observations and a simple one-dimensional, gasdynamic code, we have explored how initial conditions affect the radial evolution of solar wind disturbances associated with overexpanding CMEs. We find good qualitative agreement between the results of our simulations and Ulysses observations of such disturbances. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Gosling, JT (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM jgosling@lanl.gov NR 34 TC 70 Z9 70 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1998 VL 103 IS A2 BP 1941 EP 1954 DI 10.1029/97JA01304 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YV622 UT WOS:000071845800006 ER PT J AU Anderson, DN Buonsanto, MJ Codrescu, M Decker, D Fesen, CG Fuller-Rowell, TJ Reinisch, BW Richards, PG Roble, RG Schunk, RW Sojka, JJ AF Anderson, DN Buonsanto, MJ Codrescu, M Decker, D Fesen, CG Fuller-Rowell, TJ Reinisch, BW Richards, PG Roble, RG Schunk, RW Sojka, JJ TI Intercomparison of physical models and observations of the ionosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GENERAL-CIRCULATION MODEL; LOW MAGNETIC ACTIVITY; INTERNATIONAL REFERENCE IONOSPHERE; HIGH-LATITUDE IONOSPHERE; PEAK ELECTRON-DENSITY; HEAT-FLOW EQUATIONS; WINTER F-REGION; SOLAR MINIMUM; ION TEMPERATURE; MILLSTONE HILL AB Five physical models of the ionosphere were compared with each other and with data obtained at the Millstone Hill Observatory. Two of the models were self-consistent ionosphere-thermosphere models, while for the other ionospheric models the thermospheric parameters were provided by empirical inputs. The comparisons were restricted to midlatitudes and low geomagnetic activity, but four geophysical cases were considered that covered both the summer and winter solstices at solar maximum and minimum. The original motivation of the study was to determine why several physical models consistently underestimated the F region peak electron density, by up to a factor of 2, in the midlatitude, daytime ionosphere at solar maximum. This problem was resolved, but the resolution did not identify alack of physics in any of the models. Instead, various chemical reaction rates, photoionization processes, and diffusion coefficients had to be adjusted, with the main one being the adoption of the Burnside factor of 1.7 for the diffusion coefficients. The subsequent comparisons of the models and data were for "standard" simulations in which uncertain inputs or processes were not adjusted to get better agreement with the data. For these comparisons, the five models displayed diurnal variations that, in general, agreed with the measurements. However, each one of the five models exhibited a clear deficiency in at least one of the four geophysical cases that was not common to the other models. Therefore, contrary to expectations, the coupled ionosphere-thermosphere models were not found to be superior to the uncoupled ionospheric models for the cases considered. The spread in NmF2 calculated by the five models was typically less than a factor of 2 during the day but was as large as a factor of 10 at certain local times during the night. The latter problem was traced to insufficient nocturnal maintenance processes in two of the uncoupled ionospheric models. The general findings of this study have important implications for the National Space Weather Program. C1 Phillips Lab, PL GPIM, Hanscom AFB, MA 01731 USA. MIT, Haystack Observ, Atmospher Sci Grp, Westford, MA 01886 USA. NOAA, Environm Res Lab, Space Environm Lab, R E SEL, Boulder, CO 80303 USA. Boston Coll, Space Res Inst, Chestnut Hill, MA 02167 USA. Univ Texas, WB Hanson Ctr Space Sci, Richardson, TX 75083 USA. Univ Massachusetts, Ctr Atmospher Res, Lowell, MA 01854 USA. Univ Alabama, Dept Comp Sci, Huntsville, AL 35899 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Utah State Univ, Ctr Atmospher & Space Sci, Logan, UT 84322 USA. RP Phillips Lab, PL GPIM, Hanscom AFB, MA 01731 USA. NR 75 TC 60 Z9 62 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1998 VL 103 IS A2 BP 2179 EP 2192 DI 10.1029/97JA02872 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YV622 UT WOS:000071845800028 ER PT J AU Phan, LT Carino, NJ AF Phan, LT Carino, NJ TI Review of mechanical properties of HSC at elevated temperature SO JOURNAL OF MATERIALS IN CIVIL ENGINEERING LA English DT Review AB A compilation of experimental results on the mechanical properties of concrete when exposed to rapid heating as in a fire are presented. Emphasis is placed on concretes with high original compressive strengths, that is, high-strength concretes (HSCs). The compiled test data were categorized by the test methods and the types of aggregate used and compared for behavioral differences. The comparison revealed distinct difference in mechanical properties of HSC and normal-strength concrete (NSC) in the range between room temperature and approximately 450 degrees C. The differences narrowed at temperature above 450 degrees C. Also presented is a comparison of these test results with existing code provisions on the effects of elevated temperature on concrete strength. It is shown that the Eurocode provisions and the Comites Euro-International Du Seton (CEB) design curves are more applicable to NSC than to HSC. In fact, these provisions are unsafe when compared with HSC test results. The study showed a lack of experimental data for lightweight HSC and HSC heated under a constant preload to simulate the stress conditions in HSC columns. C1 NIST, Bldg & Fire Res Lab, Struct Div, Struct Evaluat Grp, Gaithersburg, MD 20899 USA. RP Phan, LT (reprint author), NIST, Bldg & Fire Res Lab, Struct Div, Struct Evaluat Grp, Gaithersburg, MD 20899 USA. NR 21 TC 110 Z9 122 U1 1 U2 22 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0899-1561 J9 J MATER CIVIL ENG JI J. Mater. Civ. Eng. PD FEB PY 1998 VL 10 IS 1 BP 58 EP 64 DI 10.1061/(ASCE)0899-1561(1998)10:1(58) PG 7 WC Construction & Building Technology; Engineering, Civil; Materials Science, Multidisciplinary SC Construction & Building Technology; Engineering; Materials Science GA YT179 UT WOS:000071573400010 ER PT J AU Hwang, CS Vaudin, MD Schenck, PK AF Hwang, CS Vaudin, MD Schenck, PK TI Influence of the microstructure of Pt/Si substrates on textured growth of barium titanate thin films prepared by pulsed laser deposition SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB Pt-coated silicon substrates with strong (111) Pt texture were annealed in an oxidizing atmosphere at temperatures from 500 degrees C to 750 degrees C. BaTiO3 thin films were deposited by pulsed laser ablation on the substrates. Observation by transmission electron microscopy showed that the substrate anneal caused the formation of TiO2 in the Pt layer, accompanied by the formation of a high density of faceted protrusions on the Pt surface, particularly at the higher anneal temperatures. The Pt protrusions had (111) facets, parallel to the substrate surface, on which (100)-oriented BaTiO3 grains were observed. BaTiO3 grains with an epitaxial relationship to the Pt lattice were observed on inclined facets of the Pt protrusions [which were not (111) planes], and also on the nonplanar regions of the Pt surface. These epitaxial BaTiO3 grains had (111) preferred orientation relative to the substrate surface. Thus, the BaTiO3 films displayed bimodal growth behavior, with both (100) texture and (111) epitaxy. We propose a model for this behavior based on surface energy considerations. C1 NIST, Gaithersburg, MD 20899 USA. RP Hwang, CS (reprint author), Samsung Elect Co Ltd, Kihung, South Korea. RI Hwang, Cheol Seong/C-8568-2009 NR 18 TC 26 Z9 26 U1 0 U2 7 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 FEB PY 1998 VL 13 IS 2 BP 368 EP 375 DI 10.1557/JMR.1998.0049 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA ZJ205 UT WOS:000073190000018 ER PT J AU Merzbacher, CI Barker, JG Swider, KE Rolison, DR AF Merzbacher, CI Barker, JG Swider, KE Rolison, DR TI Effect of re-wetting on silica aerogel structure: a SANS study SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Letter ID NEUTRON-SCATTERING AB Small angle neutron scattering (SANS) has been used to study (1) the ability to refill the pores of a silica aerogel (rho = 0.3 g/cm(3)) with water and (2) and effect of the water and the re-wetting process on the aerosol structure on the 1 nm to 100 nm scale. A sample filled with a D2O:H2O solution which was chosen tu match the scattering properties of silica shows no scattering at length scales < 40 nm down to the detection limit (similar to 2 nm) of the experiment. This lack of scattering demonstrates that the mesopores of the silica aerogel were successfully filled with the contrast-matching fluid. SANS spectra for samples filled with air or D2O are similar, indicating that the aerogel structure as detected by this technique is not affected by the reintroduction of water into the pores. Results suggest that some aerogels may be suited for applications in aqueous environments such as catalysis or chemical sensing. (C) 1998 Elsevier Science B.V. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Merzbacher, CI (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. EM merzbacher@nrl.navy.mil NR 18 TC 13 Z9 13 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD FEB PY 1998 VL 224 IS 1 BP 92 EP 96 DI 10.1016/S0022-3093(97)00454-7 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZB560 UT WOS:000072484800013 ER PT J AU Grey, IE Li, C Cranswick, LMD Roth, RS Vanderah, TA AF Grey, IE Li, C Cranswick, LMD Roth, RS Vanderah, TA TI Structure analysis of the 6H-Ba(Ti,Fe3+,Fe4+)O3-delta solid solution SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID NEUTRON POWDER DIFFRACTION; RIETVELD ANALYSIS; REFINEMENT AB The 6H form of BaTiO3 forms an extensive solid solution with barium iron oxide, having the general formula BaTi1-x-yFex3+ Fey4+O3-x/2, where the Fe3+/Fe4+ ratio depends on reaction temperature and gas atmosphere. Two series of solid solutions with iron predominantly in the form Fe3+ or Fe4+ were prepared by quenching from high temperatures in air or slow cooling to 200 degrees C in oxygen, respectively. The structural variations in both series were obtained from Rietveld refinements of powder X-ray diffraction data, For the series with y similar to 0, the progressive substitution of Ti4+ by Fe3+ is accompanied by the formation of O(1) oxygen vacancies in the h-BaO3 layers that separate pairs of occupied face-shared octahedra, The maximum vacancy concentration occurs at x = 0.67 which corresponds to a composition of Ba square O-2 (square = vacancy) in the h-stacked layers. Solid solution members with x > 0.67 were unstable relative to other polymorphs Further incorporation of iron into the 6H structure at high temperature occurs by substitution of Ti4+ by Fe4+, i.e., by increasing y. The observed structural variations in the solid solution phases are explained in terms of the Ba and Fe, Ti atom packing and the changes in interatomic interactions between the metal atoms as oxygen is removed from the O(1) site. (C) 1998 Academic Press. C1 CSIRO, Div Minerals, Clayton, Vic 3168, Australia. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Grey, IE (reprint author), CSIRO, Div Minerals, Clayton, Vic 3168, Australia. NR 21 TC 73 Z9 74 U1 1 U2 6 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD FEB 1 PY 1998 VL 135 IS 2 BP 312 EP 321 DI 10.1006/jssc.1997.7652 PG 10 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA ZF465 UT WOS:000072900200016 ER PT J AU Johnson, LE Kucera, P Lusk, C Roberts, WF AF Johnson, LE Kucera, P Lusk, C Roberts, WF TI Usability assessments for hydrologic forecasting DSS SO JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION LA English DT Article DE surface water hydrology; flood forecasting; decision support system; usability AB Usability assessments were used to obtain feedback on the development of a flood forecasting decision support system. The feedback was used to guide design of system functionality, interface, training, implementation, and operations. The usability process was user focused and was dependent upon implementation of a prototype system in an operational setting. This paper describes concepts and methods applied to collect reflective and objective data on DSS components and information outputs. The general structure of the usability assessments is discussed and results of assessments are summarized. C1 Univ Colorado, Dept Civil Engn, Denver, CO 80217 USA. NOAA, Forecast Syst Lab, Evaluat Team, Boulder, CO 80303 USA. RP Johnson, LE (reprint author), Univ Colorado, Dept Civil Engn, CB 113,POB 173364, Denver, CO 80217 USA. NR 24 TC 2 Z9 2 U1 0 U2 1 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 20170-5531 USA SN 0043-1370 J9 J AM WATER RESOUR AS JI J. Am. Water Resour. Assoc. PD FEB PY 1998 VL 34 IS 1 BP 43 EP 56 DI 10.1111/j.1752-1688.1998.tb05959.x PG 14 WC Engineering, Environmental; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA ZB945 UT WOS:000072524100005 ER PT J AU Guttman, NB AF Guttman, NB TI Comparing the Palmer Drought Index and the standardized precipitation index SO JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION LA English DT Article DE precipitation; drought; drought index; climatology; time series analysis ID SEVERITY INDEX; UNITED-STATES; L-MOMENTS; SENSITIVITY AB The Palmer Drought Index (PDI) is used as an indicator of drought severity, and a particular index value is often the signal to begin or discontinue elements of a drought contingency plan. The Standardized Precipitation Index (SPI) was recently developed to quantify a precipitation deficit for different time scales. It was designed to be an indicator of drought that recognizes the importance of time scales in the analysis of water availability and water use. This study compares historical time series of the PDI with time series of the corresponding SPI through spectral analysis. Results show that the spectral characteristics of the PDI vary from site to site throughout the U.S., while those of the SPI do not vary from site to site. They also show that the PDI has a complex structure with an exceptionally long memory, while the SPI is an easily interpreted, simple moving average process. C1 Natl Climat Data Ctr, Asheville, NC 28801 USA. RP Guttman, NB (reprint author), Natl Climat Data Ctr, 151 Patton Ave, Asheville, NC 28801 USA. NR 15 TC 371 Z9 413 U1 7 U2 72 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 20170-5531 USA SN 0043-1370 J9 J AM WATER RESOUR AS JI J. Am. Water Resour. Assoc. PD FEB PY 1998 VL 34 IS 1 BP 113 EP 121 DI 10.1111/j.1752-1688.1998.tb05964.x PG 9 WC Engineering, Environmental; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA ZB945 UT WOS:000072524100010 ER PT J AU Kiladis, GN AF Kiladis, GN TI Observations of Rossby waves linked to convection over the eastern tropical Pacific SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID WAVENUMBER-FREQUENCY DOMAIN; UPPER TROPOSPHERIC WAVES; VARYING BASIC STATE; ENERGY ACCUMULATION; EXTRATROPICAL INTERACTION; POTENTIAL VORTICITY; GENERAL-CIRCULATION; EQUATORIAL PACIFIC; VERTICAL STRUCTURE; NORTHERN WINTER AB Rossby wave activity propagating into the eastern tropical Pacific from the midlatitudes during northern winter is examined in some detail. These waves are associated with the intrusion of high potential vorticity air into low latitudes, and they modulate cloudiness, stability, and vertical motion in the vicinity of the ITCZ. In the upper troposphere and lower stratosphere the horizontal phase and group propagation of the wave activity are qualitatively like those of a nondivergent barotropic Rossby wave. As the waves move equatorward, they become more shallow and propagate upward into the stratosphere. The horizontal and vertical propagation is consistent with the tilts of the waves, the large-scale three-dimensional background flow, and with the signatures of momentum and heat fluxes associated with the wave activity. In the lower troposphere, paired cyclonic anomalies on either side of the equator accompany the upper level wave activity to the west of the ITCZ cloudiness signal. These waves amplify following the peak in the ITCZ cloudiness and propagate westward along the equator. This suggests that the upper-level wave activity, and possibly the associated convective heating, can trigger the excitation of the equatorially trapped Rossby modes. The transient wave activity appears to be a crucial component of the momentum balance of the eastern tropical Pacific circulation. There is substantial interannual variability in the wave activity, consistent with observed changes in the large-scale basic state associated with the Southern Oscillation. C1 NOAA, Aeron Lab, ERL, Boulder, CO 80303 USA. RP Kiladis, GN (reprint author), NOAA, Aeron Lab, ERL, 325 Broadway,R-E-AL3, Boulder, CO 80303 USA. NR 49 TC 94 Z9 94 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD FEB 1 PY 1998 VL 55 IS 3 BP 321 EP 339 DI 10.1175/1520-0469(1998)055<0321:OORWLT>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YX384 UT WOS:000072017800003 ER PT J AU Liu, AS AF Liu, AS TI Cavity- and light-induced enhancement in the intersubband sum-frequency generation of a quantum well inside a microcavity SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID OPTICAL 2ND-HARMONIC GENERATION; 2ND-ORDER SUSCEPTIBILITY; ELECTRIC-FIELD; HETEROSTRUCTURES; SEMICONDUCTORS; TRANSITION AB We present a nonlocal local-field calculation of optical sum-frequency generation (SFG) in a quantum well (QW) associated with intersubband processes. The QW is positioned inside a microcavity and pumped by a strong light beam as one of the fundamental waves for the SFG. The third-order optical nonlinearity of the QW in connection with the strong field is included in the calculation of the sum-frequency (SF) conversion efficiency. From the microscopic Maxwell-Lorentz equation combined with light-induced linear and third-order nonlinear current densities, we solve the fundamental and SF local fields exactly. In turn we define the conversion efficiency of the SFG. For a GaAs/Al0.4Ga0.6As QW placed between vacuum and a GaAs/AlAs distributed Bragg reflector (DBR) followed by a GaAs prism, we calculate the SF energy reflection spectra for different values of the incident Light intensity and the DBR period. The numerical results show that a significant enhancement of the SF conversion efficiency occurs when the DBR period and the input light intensity are optimally chosen. This is attributed to the cavity- and light-induced local-field enhancement in the QW system. (C) 1998 Optical Society of America. C1 Univ Aalborg, Inst Phys, DK-9220 Aalborg, Denmark. RP Liu, AS (reprint author), NIST, Div Atom Phys, Gaithersburg, MD 20899 USA. NR 28 TC 0 Z9 0 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD FEB PY 1998 VL 15 IS 2 BP 586 EP 593 DI 10.1364/JOSAB.15.000586 PG 8 WC Optics SC Optics GA YX192 UT WOS:000072015600009 ER PT J AU Hebner, R AF Hebner, R TI Converting technology to commerce SO LASER FOCUS WORLD LA English DT Editorial Material C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Hebner, R (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO PI NASHUA PA 5TH FLOOR TEN TARA BOULEVARD, NASHUA, NH 03062-2801 USA SN 0740-2511 J9 LASER FOCUS WORLD JI Laser Focus World PD FEB PY 1998 VL 34 IS 2 BP 67 EP 68 PG 2 WC Optics SC Optics GA YW547 UT WOS:000071947300022 ER PT J AU Peng, TH Key, RM Ostlund, HG AF Peng, TH Key, RM Ostlund, HG TI Temporal variations of bomb radiocarbon inventory in the Pacific Ocean SO MARINE CHEMISTRY LA English DT Article; Proceedings Paper CT 1st International Meeting on Carbon Dioxide in the Oceans CY JAN, 1996 CL MAYAGUEZ, PUERTO RICO DE Pacific Ocean; C-14/C-12; temporal variations; seawater ID CIRCULATION MODEL; DISTRIBUTIONS; SIMULATIONS; C-14 AB The natural and anthropogenic components of the radiocarbon measurements from seawater samples can be successfully separated by an improved method, which is based on a very well-defined relationship between natural radiocarbon and dissolved silica observed mainly during the GEOSECS survey for waters beneath 1000 m depth. This relationship is further reconfirmed by the C-14 measurements from large volume samples taken in the deep waters in the Pacific Ocean during the recent WOCE survey program. Analysis of upper ocean C-14 measurements made along 152 degrees W, and north of 20 degrees N, in the northeastern Pacific Ocean during the NOAA's CGC91 cruise, which is a part of the WOCE survey program, indicates that the bomb C-14 inventory in this part of the ocean has increased by 22% since the GEOSECS measurements made in 1974, This increase is consistent with the model prediction of 25% for the northern hemisphere ocean. Change of the surface water bomb Delta(14)C values during this period is insignificant, This feature is also consistent with the model simulation. Results of this new analysis will provide useful information of the temporal variations of bomb C-14 inventory in the ocean, in addition to the spatial distribution, which can be used as powerful constraints in calibrating the global ocean carbon cycle models, especially those based on three-dimensional ocean general circulation models, for estimating the uptake of CO2 by the ocean. (C) 1998 Elsevier Science B.V. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Div, Miami, FL 33149 USA. Princeton Univ, Dept Geol & Geophys Sci, Princeton, NJ 08544 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RP Peng, TH (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. NR 18 TC 22 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD FEB PY 1998 VL 60 IS 1-2 BP 3 EP 13 DI 10.1016/S0304-4203(97)00089-3 PG 11 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA ZM128 UT WOS:000073507500002 ER PT J AU Wanninkhof, R Feely, RA AF Wanninkhof, R Feely, RA TI fCO(2) dynamics in the Atlantic, South Pacific and South Indian oceans SO MARINE CHEMISTRY LA English DT Article; Proceedings Paper CT 1st International Meeting on Carbon Dioxide in the Oceans CY JAN, 1996 CL MAYAGUEZ, PUERTO RICO DE chemical oceanography; carbon system; Atlantic Ocean; Indian Ocean; Pacific Ocean ID ISOPYCNAL SURFACES; REDFIELD RATIOS; SEAWATER; CO2; PRESSURE; WATER; SOLUBILITY; ICELAND; SYSTEM AB Subsurface fugacities of CO2 (f(CO2)(20)) can be used in combination with total dissolved inorganic carbon (DIC) to precisely calculate total alkalinity. Thus it can be used to determine dissolution of calcium carbonate (hard tissue) and remineralization of organic material (soft tissue), to quantify saturation constants of calcite and aragonite in seawater, and to characterize water masses. f(CO2)(20) is a good tracer of biological transformation since it is thermodynamically related to the other inorganic carbon system parameters and it has a dynamic range from 200 to 2000 mu atm in the world's ocean. Precision of f(CO2) measurements is 0.3% and the values are well calibrated using compressed gas reference standards. Increases of f(CO2)(20) are observed as the water masses age during movement from the Atlantic to the Indian and South Pacific oceans. As an example of the determination of the ratio of soft tissue remineralization to hard tissue dissolution from f(CO2)(20) and DIC, the trends along the 27.2 isopycnal for the subtropical gyres of the three basins are investigated. Little CaCO3 dissolves along this isopycnal in the Atlantic and the South Pacific while the soft tissue remineralization to hard tissue dissolution ratio in Indian Ocean is 4.5:1. The difference in this ratio along the 27.2 isopycnal appears to be a combination of the calcite and aragonite saturation levels and the supply of aragonite tests. (C) 1998 Elsevier Science B.V. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Dept, Miami, FL 33149 USA. NOAA, Pacific Marine Environm Lab, Ocean Climate Res Div, Seattle, WA 98115 USA. RP Wanninkhof, R (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Dept, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. EM wanninkhof@aomI.noaa.gov NR 32 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD FEB PY 1998 VL 60 IS 1-2 BP 15 EP 31 DI 10.1016/S0304-4203(97)00088-1 PG 17 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA ZM128 UT WOS:000073507500003 ER PT J AU McElligott, S Byrne, RH Lee, K Wanninkhof, R Millero, FJ Feely, RA AF McElligott, S Byrne, RH Lee, K Wanninkhof, R Millero, FJ Feely, RA TI Discrete water column measurements of CO2 fugacity and pH(T) in seawater: A comparison of direct measurements and thermodynamic calculations SO MARINE CHEMISTRY LA English DT Article; Proceedings Paper CT 1st International Meeting on Carbon Dioxide in the Oceans CY JAN, 1996 CL MAYAGUEZ, PUERTO RICO DE seawater; carbon dioxide; fugacity; spectrophotometric pH; measurements; thermodynamic calculations ID CARBONIC-ACID; DISSOCIATION-CONSTANTS; PH MEASUREMENTS; CONSISTENCY; SYSTEM AB The NOAA Eq. Pac. CO2 system data set (similar or equal to 2500 water samples) has been evaluated to assess the internal consistency of measurements and calculations involving CO2 fugacity and pH(T). This assessment represents the first large scale field comparison of pH(T) and f(CO2) data. Comparisons of direct discrete CO2 fugacity (f(CO2)) measurements with CO2 fugacity calculated from total inorganic carbon (C-T), total alkalinity (A(T)) and spectrophotometric pH (pH(T) = -log[H+](T)) indicate that a variety of improvements are needed in the parameter measurements and thermodynamic relationships used to relate f(CO2), C-T, A(T) and pH(T) in seawater. CO2 fugacity calculated from C-T and pH(T) or A(T) and pH(T) agree with direct measurements to no better than 1%. Comparisons of measured fugacity, f(CO2) (measured), and CO2 fugacity calculated from C-T and pH(T), f(CO2) (C-T, pH(T)), indicate that the precision of f(CO2) calculations is good relative to direct measurements. In contrast, due to the extreme sensitivity of f(CO2) and [H+](T) calculations to relatively small errors in both C-T and A(T), CO2 fugacity, as well as [H+](T), calculated from C-T and A(T) are very imprecise and render comparisons with direct measurements of little use. Consequently, precise calculations of f(CO2) require the use of direct pH(T) measurements. (C) 1998 Elsevier Science B.V. C1 Univ S Florida, Dept Marine Sci, St Petersburg, FL 33701 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Byrne, RH (reprint author), Univ S Florida, Dept Marine Sci, 140 7Th Ave S, St Petersburg, FL 33701 USA. RI Lee, Kitack/G-7184-2015 NR 20 TC 42 Z9 42 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD FEB PY 1998 VL 60 IS 1-2 BP 63 EP 73 DI 10.1016/S0304-4203(97)00080-7 PG 11 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA ZM128 UT WOS:000073507500006 ER PT J AU Sabine, CL Key, RM AF Sabine, CL Key, RM TI Controls on f(CO2) in the South Pacific SO MARINE CHEMISTRY LA English DT Article; Proceedings Paper CT 1st International Meeting on Carbon Dioxide in the Oceans CY JAN, 1996 CL MAYAGUEZ, PUERTO RICO DE Southern Ocean; carbon dioxide; Pacific; P-CO2; anthropogenic ID CARBON-DIOXIDE; PARTIAL-PRESSURE; CO2; SEAWATER; OCEAN; WATER; THERMODYNAMICS; DISTRIBUTIONS; DISSOCIATION; TEMPERATURE AB One aspect of the JGOFS/WOCE programs is the generation of a global CO2 data set which will be significantly better in sampling density and quality than existed before. This data will be extremely valuable to geochemists and modelers interested in the global carbon cycle. Nevertheless, it will still be necessary to interpolate measurements both temporally and spatially to incorporate the results into global circulation models. This paper presents a new method that attempts to quantify the processes known to influence surface ocean CO2 fugacity. The method is tested using data collected along a Pacific WOCE section (P17E) across the Southern Ocean. These calculations offer more insight into the factors controlling f(CO2) than published analysis/interpolation schemes in that individual effects are quantified without resorting to empirical relationships. The procedure works extremely well for spatial interpolation along section P17E and sheds insight into physical processes (mixing and air-sea gas exchange) where model results differ from observations. If the method proves to be robust when applied to other areas, it will be a significant step toward interpolation of sparse ocean CO2 measurements in order to calculate either regional or global CO2 fluxes. (C) 1998 Elsevier Science B.V. C1 Princeton Univ, Dept Geosci, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. RP Sabine, CL (reprint author), Princeton Univ, Dept Geosci, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. EM sabine@geo.princeton.edu NR 47 TC 26 Z9 29 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD FEB PY 1998 VL 60 IS 1-2 BP 95 EP 110 DI 10.1016/S0304-4203(98)00086-3 PG 16 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA ZM128 UT WOS:000073507500009 ER PT J AU Myers, MS Johnson, LL Hom, T Collier, TK Stein, JE Varanasi, U AF Myers, MS Johnson, LL Hom, T Collier, TK Stein, JE Varanasi, U TI Toxicopathic hepatic lesions in subadult English sole (Pleuronectes vetulus) from Puget Sound, Washington, USA: Relationships with other biomarkers of contaminant exposure SO MARINE ENVIRONMENTAL RESEARCH LA English DT Article DE biomarkers of contaminant exposure and effects; toxicopathic hepatic lesion fish; epizootiology; histopathology ID FLOUNDER PSEUDOPLEURONECTES-AMERICANUS; POLYCYCLIC AROMATIC-HYDROCARBONS; PAROPHRYS-VETULUS; TOXIC-CHEMICALS; UNITED-STATES; DNA ADDUCTS; P-32-POSTLABELING ANALYSIS; MARINE SEDIMENT; POLLUTED AREAS; FISH AB Liver neoplasms are rarely detected in young wild fish. Therefore, other lesions occurring early in the histogenesis of hepatic neoplasia need to be considered as biomarkers of chemical contaminant exposure effects in monitoring studies, especially where adult fish are nor available. Moreover, exposure effects may be more reliably assessed in younger fish that have not yet migrated extensively. Accordingly, livers of subadult English sole were histologically examined from nine sires in Puget Sound, WA and the same fish were assessed for contaminant exposure by measurement of fluorescent aromatic compounds (FACs) in bile, hepatic levels of polychlorinated biphenyls (PCBs) and cytochrome P4501A (CYP1A) as catalytic activity of aryl hydrocarbon hydroxylase (AHH), and hydrophobic DNA adducts in liver by (32)P-postlabelling. Although neoplasms were rare, higher prevalences of preneoplastic, regenerative, and unique degenerative/ necrotic lesions were detected in sole from contaminated sites. Prevalences of these early histopathologic biomarkers were significantly higher at the more contaminated sites, and concentration of mean biliary FACs at each capture site was a significant risk factor for most lesions, as determined by stepwise logistic regression. By this statistical method, we also demonstrated that several measures of bioaccumulation or biochemical response to contaminants were significant and near-significant risk factors for prevalences of most hepatic lesion categories. For example, mean hepatic AHH activity was a significant risk factor for prevalence of all lesion types, except neoplasms; hepatic PCB and xenobiotic-DNA adduct concentrations were significant risk factors for the most frequently detected lesion category, hepatocellular nuclear pleomorphism/megalocytic hepatosis, and the inclusive category 'any early toxicopathic lesion'. These findings further support the utility of certain non-neoplastic liver lesions as early indicators of biological damage in subadult as well as adult fish exposed to xenobiotics in the marine environment. Published by Elsevier Science Ltd. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, Seattle, WA 98112 USA. RP Myers, MS (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Environm Conservat Div, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 70 TC 100 Z9 103 U1 2 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 FEB PY 1998 VL 45 IS 1 BP 47 EP 67 DI 10.1016/S0141-1136(97)00021-4 PG 21 WC Environmental Sciences; Marine & Freshwater Biology; Toxicology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Toxicology GA YT696 UT WOS:000071633900004 ER PT J AU O'Shea, TJ Brownell, RL AF O'Shea, TJ Brownell, RL TI California sea lion (Zalophus californianus) populations and Sigma DDT contamination SO MARINE POLLUTION BULLETIN LA English DT Article ID ORGANOCHLORINE COMPOUNDS; REPRODUCTIVE TRANSFER; PHOCA-VITULINA; HARBOR SEALS; HARP SEALS; RESIDUES; WHALES; POLLUTANTS; GREENLAND; BIPHENYLS C1 US Geol Survey, Biol Resources Div, Midcontinent Ecol Sci Ctr, Ft Collins, CO 80525 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92037 USA. RP US Geol Survey, Biol Resources Div, Midcontinent Ecol Sci Ctr, 4512 McMurry Ave, Ft Collins, CO 80525 USA. NR 49 TC 15 Z9 15 U1 2 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD FEB PY 1998 VL 36 IS 2 BP 159 EP 164 DI 10.1016/S0025-326X(97)00102-1 PG 6 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA ZM703 UT WOS:000073567400014 ER PT J AU Siewert, TA AF Siewert, TA TI The International Institute of Welding: Report on 1997 actions SO MATERIALS EVALUATION LA English DT Article C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Siewert, TA (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD FEB PY 1998 VL 56 IS 2 BP 153 EP + PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA YY505 UT WOS:000072154200004 ER PT J AU Chen-Mayer, HH Lamaze, GP AF Chen-Mayer, HH Lamaze, GP TI Depth distribution of boron determined by slow neutron induced lithium ion emission SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 17th International Conference on Atomic Collisions in Solids (ICACS-17) CY JUL 02-06, 1997 CL BEIJING, PEOPLES R CHINA DE Neutron Depth Profiling; boron distribution in thin films; stopping power of Li and alpha particles AB Neutron Depth Profiling (NDP) has been established as a non-destructive technique to determine the near surface distribution of light elements, particularly boron. By analyzing the residual energy spectrum of the emitted particles of known initial energy as a result of nuclear capture within the target material, information about the site and amount of the reactions can be deduced. In the event of B-10 neutron capture, an alpha particle (1473 keV) and an excited Li-7 ion (840 keV) are emitted, both conveying the same information. However, because the Li ion has a greater charge, the stopping power in a given matrix is higher than that for the alpha particle. Consequently, for boron near the surface, the location of the origin of the emission can be determined with better depth resolution. At the NIST NDP facility, routine analysis using the alpha particle has been established earlier. This paper reports the progress of using the Li-7 ion stopping power to determine the boron depth distribution in the near surface of several matrices. This study has been performed on semiconductor device-related systems - boron in silicon glass, and carbon matrices. Various factors affecting the depth resolution are assessed when comparing the analysis of the alpha particle with that of the Li-7 ion. (C) 1998 Elsevier Science B.V. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Chen-Mayer, HH (reprint author), NIST, Chem Sci & Technol Lab, Bldg 235,Room B125, Gaithersburg, MD 20899 USA. NR 12 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD FEB PY 1998 VL 135 IS 1-4 BP 407 EP 412 DI 10.1016/S0168-583X(97)00618-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW291 UT WOS:000074395300075 ER PT J AU Berger, MJ AF Berger, MJ TI A method for determining the 2 pi-counting efficiency of beta-particle sources SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE beta particle source; estimate of efficiency; backscattering; self absorption ID LOW-ENERGY ELECTRONS AB This paper is concerned with the efficiency of large-area beta-particle sources. Attention is focussed on sources in which the radioactivity is distributed in a surface layer of an anodized aluminum foil. The efficiency lakes into account the reflection and absorption of particles in the aluminum foil. and is defined as the ratio of the number of particles emerging from the foil to the number of particles emitted. A method of estimating the efficiency is proposed which combines measurements and transport calculations. The experimental part of the method consists of measuring the thickness of the layer of mylar which, when inserted between source and detector. cuts the counting rate in half. The theoretical part consists of calculations of beta-particle transport in a two-layer aluminium-mylar medium, which relate the efficiency of the source to the thickness of the measured half-value layer. Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Berger, MJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 17 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD FEB PY 1998 VL 134 IS 2 BP 276 EP 286 DI 10.1016/S0168-583X(98)00550-3 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YZ381 UT WOS:000072248700018 ER PT J AU Wischnewski, A Buchenau, U Dianoux, AJ Kamitakahara, WA Zarestky, JL AF Wischnewski, A Buchenau, U Dianoux, AJ Kamitakahara, WA Zarestky, JL TI Neutron scattering analysis of low-frequency modes in silica SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article; Proceedings Paper CT 6th International Workshop on Disordered Systems CY MAR 03-06, 1997 CL ANDALO, ITALY SP Univ Trento, Dipartiemento Fis, Grp Nazl Struttura Mat, Consiglio Nazl Ric, Cassa Risparmio Trento & Rovereto ID THERMAL-CONDUCTIVITY; VITREOUS SILICA; BRILLOUIN-SCATTERING; PHONON LOCALIZATION; AMORPHOUS SOLIDS; GLASSES; HEAT; BEHAVIOR; DYNAMICS AB We report coherent inelastic neutron scattering results in vitreous silica at temperatures up to 1673 K, 200 K above the glass transition. As in earlier low-temperature data, clear evidence is seen for non-sound-wave modes at the boson peak. Contrary to other glass formers, silica shows nearly no fast relaxations at the glass transition. The combination of the neutron spectra with recent X-ray Brillouin data allows the identification of the scattering mechanisms for high-frequency sound waves in the glass. Below 1 THz, one has resonant scattering from low-frequency vibrations and above 1 THz, Rayleigh scattering from the atomic disorder. C1 Forschungszentrum Julich, Inst Festkorperforsch, D-52425 Julich, Germany. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. NIST, Div Reactor Radiat, Gaithersburg, MD 20899 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Forschungszentrum Julich, Inst Festkorperforsch, Postfach 1913, D-52425 Julich, Germany. RI Wischnewski, Andreas/J-9415-2013 OI Wischnewski, Andreas/0000-0003-2401-2850 NR 30 TC 18 Z9 18 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD FEB PY 1998 VL 77 IS 2 BP 579 EP 589 DI 10.1080/13642819808204986 PG 11 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA YW812 UT WOS:000071976500043 ER PT J AU Levin, I Brandon, DG AF Levin, I Brandon, DG TI A new metastable alumina polymorph with monoclinic symmetry SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID CRYSTAL AB Polymorphic phase transitions between alumina structures based on fcc packing of oxygen have been studied by electron diffraction and high-resolution electron microscopy. A new metastable alumina polymorph with monoclinic symmetry was identified in alumina obtained by both plasma spraying and thermal oxidation of aluminium. The structure of this phase was described by the P2(1)/c space group and a unit cell containing 32 formula units with lattice parameters a = 8.45 Angstrom, b = 16 Angstrom, c = 12.64 Angstrom and beta = 115 degrees. It is suggested that the new phase is evolved from cubic gamma-Al2O3 by ordering of aluminium cations on interstitial sites of the fcc packed oxygen sublattice. The transformation proceeds through an orthorhombic distortion of the cubic anion structure. Crystallographic domain and interdomain boundaries in lambda-Al2O3 were identified and related to the symmetry changes which accompany gamma --> lambda phase transition. C1 Technion Israel Inst Technol, Fac Mat Engn, IL-32000 Haifa, Israel. RP Levin, I (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. RI Levin, Igor/F-8588-2010 NR 9 TC 23 Z9 23 U1 0 U2 7 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD FEB PY 1998 VL 77 IS 2 BP 117 EP 124 DI 10.1080/095008398178697 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA YV316 UT WOS:000071811000008 ER PT J AU Taylor, JE Cahn, JW AF Taylor, JE Cahn, JW TI Diffuse interfaces with sharp corners and facets: Phase field models with strongly anisotropic surfaces SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article DE anisotropy; Allen-Cahn equation; motion by weighted mean curvature; nondifferentiable surface energy ID SINGULAR PERTURBATIONS; VECTOR THERMODYNAMICS; CRYSTAL-GROWTH; MEAN-CURVATURE; MOTION; ENERGY AB We provide the general outline of an analysis of the motion of diffuse interfaces in the order-parameter (phase field) formulation which includes nondifferentiable and nonconvex gradient energy terms. Nondifferentiability leads to equilibrium and motion equations that are apparently undefined and nonconvexity leads to equations that are apparently ill-posed. The problem of nondifferentiability is resolved by using nonlocal variations to move entire facets or line segments with orientations having such facets or line segments in the underlying Wulff shape. The problem of ill-posedness is resolved by using varifolds (infinitesimally corrugated diffuse interfaces) constructed from the edges and corners in the underlying Wulff shape, or equivalently by using the convexification of the gradient energy term and then reinterpreting the solutions as varifolds. This is justified on a variational basis. We conclude that after an initial transient, level sets move by weighted mean curvature, in agreement with the sharp interface limit. We provide equations for tracking the shocks that develop as edges and corners in level sets. C1 Rutgers State Univ, Dept Math, Piscataway, NJ 08855 USA. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Rutgers State Univ, Dept Math, Piscataway, NJ 08855 USA. EM taylor@math.rutgers.edu; john.cahn@nist.gov NR 40 TC 71 Z9 72 U1 1 U2 25 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 FEB 1 PY 1998 VL 112 IS 3-4 BP 381 EP 411 DI 10.1016/S0167-2789(97)00177-2 PG 31 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA YU711 UT WOS:000071746600004 ER PT J AU Cataliotti, FS Cornell, EA Fort, C Inguscio, M Marin, F Prevedelli, M Ricci, L Tino, GM AF Cataliotti, FS Cornell, EA Fort, C Inguscio, M Marin, F Prevedelli, M Ricci, L Tino, GM TI Magneto-optical trapping of fermionic potassium atoms SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; PHOTOASSOCIATIVE SPECTROSCOPY; K-39 ATOMS; VAPOR; COLLISIONS AB We have trapped K-40 in a vapor-cell magneto-optical trap starting from a natural abundance sample. This rare, weakly radioactive atom is a fermion. The number of trapped atoms is approximately 8000, with a density of similar to 10(8) atoms/cm(3). Contrary to what is observed for the other isotopes of potassium, our data indicate that temperatures lower than the Doppler-cooling limit can be reached for K-40. We discuss the interest of these results in view of possible experiments to study a degenerate Fermi gas. [S1050-2947(98)05601-7]. C1 Univ Florence, Dipartimento Fis, I-50125 Florence, Italy. Univ Florence, European Lan Nonlinear Spect, I-50125 Florence, Italy. Ist Nazl Fis Mat, I-50125 Florence, Italy. Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Trent, Dipartimento Fis, I-38050 Povo, Italy. Univ Naples Federico II, Dipartimento Sci Fis, I-80125 Naples, Italy. RP Cataliotti, FS (reprint author), Univ Florence, Dipartimento Fis, Largo E Fermi 2, I-50125 Florence, Italy. RI Ricci, Leonardo/B-4207-2009; Marin, Francesco/I-7492-2013; Cataliotti, Francesco/K-4772-2015; OI Ricci, Leonardo/0000-0001-9454-0988; Prevedelli, Marco/0000-0002-3136-2392; Marin, Francesco/0000-0001-8227-124X; Cataliotti, Francesco/0000-0003-4458-7977; FORT, Chiara/0000-0001-8817-3077; Tino, Guglielmo M./0000-0002-7944-9825 NR 19 TC 58 Z9 59 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB PY 1998 VL 57 IS 2 BP 1136 EP 1138 DI 10.1103/PhysRevA.57.1136 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YW253 UT WOS:000071913800059 ER PT J AU Wischnewski, A Buchenau, U Dianoux, AJ Kamitakahara, WA Zarestky, JL AF Wischnewski, A Buchenau, U Dianoux, AJ Kamitakahara, WA Zarestky, JL TI Sound-wave scattering in silica SO PHYSICAL REVIEW B LA English DT Article ID THERMAL-CONDUCTIVITY; VITREOUS SILICA; BRILLOUIN-SCATTERING; PHONON LOCALIZATION; AMORPHOUS SOLIDS; GLASSES; MODEL; HEAT; DYNAMICS AB The combination of x-ray Brillouin scattering data with coherent inelastic neutron scattering results in vitreous silica allows us to identify the scattering mechanisms for high-frequency sound waves in the glass. Below one THz, one has resonant scattering from low-frequency vibrations, above one THz Rayleigh scattering from the atomic disorder. C1 Forschungszentrum Julich, Inst Festkorperforsch, D-52425 Julich, Germany. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. NIST, Div Reactor Radiat, Gaithersburg, MD 20899 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Wischnewski, A (reprint author), Forschungszentrum Julich, Inst Festkorperforsch, Postfach 1913, D-52425 Julich, Germany. RI Wischnewski, Andreas/J-9415-2013 OI Wischnewski, Andreas/0000-0003-2401-2850 NR 29 TC 65 Z9 65 U1 0 U2 11 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 FEB 1 PY 1998 VL 57 IS 5 BP 2663 EP 2666 DI 10.1103/PhysRevB.57.2663 PG 4 WC Physics, Condensed Matter SC Physics GA YV538 UT WOS:000071835100006 ER PT J AU Omenetto, N Mermet, JM Turk, GC Moore, DS Vo-Dinh, T Butler, LRP Ure, AM Gauglitz, G Melhuish, WH Miller, JN Nogar, NS Schrader, B Senemaud, C Velthorst, NH Zander, M Adams, F Andreani, AM Bacon, JR Coufal, HJ Hieftje, GM Imasaka, T Lukosz, W Sturgeon, R Velthorst, NL Wilkinson, J Willis, JP Yeung, E Danzer, K Valcarcel, M Gilbert, B Rubeska, I Bezur, L De, AK Ulubelen, A Zacharias, PS Rademeyer, CJ Volka, K Curtius, AJ Park, J Zimmer, K Pszonicki, L Batistoni, DZ AF Omenetto, N Mermet, JM Turk, GC Moore, DS Vo-Dinh, T Butler, LRP Ure, AM Gauglitz, G Melhuish, WH Miller, JN Nogar, NS Schrader, B Senemaud, C Velthorst, NH Zander, M Adams, F Andreani, AM Bacon, JR Coufal, HJ Hieftje, GM Imasaka, T Lukosz, W Sturgeon, R Velthorst, NL Wilkinson, J Willis, JP Yeung, E Danzer, K Valcarcel, M Gilbert, B Rubeska, I Bezur, L De, AK Ulubelen, A Zacharias, PS Rademeyer, CJ Volka, K Curtius, AJ Park, J Zimmer, K Pszonicki, L Batistoni, DZ TI Nomenclature, symbols, units and their usage in spectrochemical analysis - XIV - laser-based atomic spectroscopy: A new notation for spectrochemical processes - (IUPAC recommendations 1997) SO PURE AND APPLIED CHEMISTRY LA English DT Article AB This report is the 14th in a series on Spectrochemical Methods of Analysis issued by IUPAC Commission V.4. Because of the complexity and the lack of uniformity of the present nomenclature (e.g. "2 step excited resonance fluorescence", "resonance enhanced multiphoton ionization", etc.) a new way is needed to describe these transitions. The aim of this document is therefore to present a new notation, the IUPAC Notation, to describe the various processes involved in atomic laser spectroscopy. Using a few assumptions as detailed below, this notation has the advantage of being simple and systematic. States and processes can be described in a general way irrespective of the type of laser spectrometry. C1 Joint Res Ctr, Ispra Estab, I-21020 Ispra, Italy. Univ Lyons, Dept Spectroscop Anal, Lyon, France. NIST, Inorgan Analyt Res Div, Gaithersburg, MD 20899 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87544 USA. RP Omenetto, N (reprint author), Joint Res Ctr, Ispra Estab, I-21020 Ispra, Italy. RI Moore, David/C-8692-2013 NR 0 TC 2 Z9 2 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD FEB PY 1998 VL 70 IS 2 BP 517 EP 526 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA ZU823 UT WOS:000074238800048 ER PT J AU Zhang, NF AF Zhang, NF TI A statistical control chart for stationary process data SO TECHNOMETRICS LA English DT Article DE asymptotically stationary; autocorrelated data; average run length; exponentially weighted moving average; process mean shift; statistical process control ID WEIGHTED MOVING AVERAGE; RUN-LENGTH DISTRIBUTIONS; CORRELATED OBSERVATIONS; SERIAL CORRELATION; CONTROL SCHEMES; CUSUM TESTS; PERFORMANCE AB In the statistical process control environment, a primary method to deal with autocorrelated data is the use of a residual chart. Although this methodology has the advantage that it can be applied to any autocorrelated data, it needs some modeling effort in practice. In addition, the detection capability of the residual chart is not always great. This article proposes a statistical control chart for stationary process data. It is simple to implement, and no modeling effort is required. Comparisons are made among the proposed chart, the residual chart, and other charts. When the process autocorrelation is not very strong and the mean changes are not large, the new chart performs better than the residual chart and the other charts. C1 Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. RP Zhang, NF (reprint author), Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. EM nien-fan.zhang@nist.gov NR 29 TC 88 Z9 98 U1 1 U2 2 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD FEB PY 1998 VL 40 IS 1 BP 24 EP 38 DI 10.2307/1271390 PG 15 WC Statistics & Probability SC Mathematics GA YU794 UT WOS:000071755200004 ER PT J AU Sugiura, ST Dong, FM Hardy, RW AF Sugiura, ST Dong, FM Hardy, RW TI Effects of dietary supplements on the availability of minerals in fish meal; preliminary observations SO AQUACULTURE LA English DT Article DE minerals; phosphorus; digestibility; availability; absorption; supplements; citric acid ID GASTRIC-ACID SECRETION; BRUSH-BORDER MEMBRANE; TROUT ONCORHYNCHUS-MYKISS; RAINBOW-TROUT; PHOSPHATE-TRANSPORT; MICROBIAL PHYTASE; CITRIC-ACID; AMMONIUM-CHLORIDE; SALMO-GAIRDNERI; CALCIUM CITRATE AB Preliminary studies were conducted to determine if several feed supplements with the potential to improve dietary mineral availabilities in fish meal had any measurable effect in fish feeds. In the first study with rainbow trout, 11 supplements were tested: citric acid; sodium citrate; potassium chloride; sodium chloride; histamine dihydrochloride; EDTA disodium salt; sodium bicarbonate; a mixture of amino acids; ascorbic acid; a mixture of inositol and choline; and cholecalciferol. Apparent availability of calcium, phosphorus, magnesium, sodium, iron, manganese and strontium in fish meal-based diets was determined using both yttrium oxide (Y2O3) and chromium oxide (Cr2O3) as inert dietary markers. Apparent availability was expressed as the fractional net absorption (%) of minerals from diets. After a 7-day acclimation period with test diets, fecal samples were collected for five consecutive days using passive collection systems. Apparent availability of calcium, phosphorus, magnesium, iron, manganese and strontium was increased by citric acid supplementation. Apparent availability of manganese also was increased by EDTA and sodium citrate. The other supplements had no measurable effect on the apparent availability of minerals in fish meal. In the second study, the effect of supplemental citric acid was further investigated using monogastric (rainbow trout) and agastric fish (goldfish). Fish were fed far 5 weeks (rainbow trout) or 3 weeks (goldfish) with fish meal-based diets containing either 0% (control), 2% ol 5% citric acid on a dry basis. Feces were collected by settling and by stripping. Apparent availabilities of calcium and phosphorus were greatly affected by citric acid supplementation in rainbow trout but not in goldfish. Phosphorus levels in feces of fish fed a diet with 5% citric acid were approximately half of that of fish fed the control diet (0% citric acid) in the rainbow trout trial. This pattern was consistent during the 5-week feeding trial. A dietary supplement of citric acid as high as 5% did not reduce feed intake or appetite of rainbow trout. Conversely, this level of dietary acidification led to a marked reduction of feed intake in goldfish. C1 Univ Washington, Sch Fisheries, Seattle, WA 98105 USA. NOAA, Natl Marine Fisheries Serv, Seattle, WA 98112 USA. RP Hardy, RW (reprint author), Hagerman Fish Culture Expt Stn, 3059F,Natl Fish Hatchery Rd, Hagerman, ID 83332 USA. NR 67 TC 62 Z9 66 U1 3 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD JAN 30 PY 1998 VL 160 IS 3-4 BP 283 EP 303 DI 10.1016/S0044-8486(97)00302-5 PG 21 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA ZM886 UT WOS:000073586200008 ER PT J AU Itano, WM Bollinger, JJ Tan, JN Jelenkovic, B Huang, XP Wineland, DJ AF Itano, WM Bollinger, JJ Tan, JN Jelenkovic, B Huang, XP Wineland, DJ TI Bragg diffraction from crystallized ion plasmas SO SCIENCE LA English DT Article ID ONE-COMPONENT PLASMA; MONTE-CARLO CALCULATIONS; N-DEPENDENCE; STORAGE RING; EQUATION; ENERGY; STATE AB Single crystals of a one-component plasma were observed by optical Bragg diffraction, The plasmas contained 10(5) to 10(6) single-positive beryllium-9 ions ((9)Be(+)) at particle densities of 10(8) to 10(9) per cubic centimeter. In approximately spherical plasmas, single body-centered cubic (bcc) crystals or, in some cases, two or more bce crystals having fixed orientations with respect to each other were observed. In some oblate plasmas, a mixture of bce and face-centered cubic ordering was seen. Knowledge of the properties of one-component plasma crystals is required for models of white dwarfs and neutron stars, which are believed to contain matter in that form. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Itano, WM (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. EM witano@nist.gov NR 29 TC 162 Z9 163 U1 4 U2 11 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 JAN 30 PY 1998 VL 279 IS 5351 BP 686 EP 689 DI 10.1126/science.279.5351.686 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YU574 UT WOS:000071731500031 ER PT J AU Ray, EA Alexander, MJ Holton, JR AF Ray, EA Alexander, MJ Holton, JR TI An analysis of the structure and forcing of the equatorial semiannual oscillation in zonal wind SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; KELVIN WAVE VARIABILITY; MIDDLE ATMOSPHERE; UPPER-STRATOSPHERE; DATA ASSIMILATION; MESOSPHERE; SIMULATION AB The low-frequency variability in the equatorial middle atmosphere is dominated by the semiannual oscillation (SAG) and quasi-biennial (QBO) oscillation. Although the general characteristics and forcing mechanisms of these oscillations are thought to be known, these oscillations are still not well reproduced in modeling experiments of the middle atmosphere. The relatively long period (1992-1996) of Upper Atmosphere Research Satellite (UARS) measurements and U.K. Meteorological Office (UKMO) assimilated model data have been used to examine the zonal wind SAO in the upper stratosphere. The SAO in zonal wind is found to be latitudinally asymmetric about the equator with strongest amplitudes in the southern hemisphere subtropics. The latitudinal asymmetry is diagnosed by using the TEM momentum equation and UKMO data. The asymmetry is mostly due to the different phasing of the peak advective forcing by the mean meridional circulation in each hemisphere. The contribution of gravity waves to the zonal wind SAO are also explored by using the forcing from a linear gravity wave model. Gravity waves are found to be the primary source of westerly momentum in each hemisphere during fall and contribute to the latitudinal asymmetry of the SAO by having more easterly forcing in the southern hemisphere during summer compared to in the northern hemisphere during summer. C1 Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. RP Ray, EA (reprint author), NOAA, Climate Monitoring & Diagnost Lab, MS R E CG1, Nitrous Oxide & Halcpds Grp, 325 Broadway, Boulder, CO 80303 USA. EM eray@cmdl.noaa.gov; alexand@atmos.washington.edu; holton@atmos.washington.edu RI Ray, Eric/D-5941-2013 OI Ray, Eric/0000-0001-8727-9849 NR 37 TC 37 Z9 37 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JAN 27 PY 1998 VL 103 IS D2 BP 1759 EP 1774 DI 10.1029/97JD02679 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YU776 UT WOS:000071753000002 ER PT J AU Migler, KB Han, CC AF Migler, KB Han, CC TI Static and kinetic study of a pressure induced order-disorder transition: Birefringence and neutron scattering SO MACROMOLECULES LA English DT Article ID SYMMETRICAL DIBLOCK COPOLYMER; MICROPHASE SEPARATION; BLOCK-COPOLYMERS; POLYMER BLENDS; LIGHT-SCATTERING; PHASE; COMPRESSIBILITY; DEPENDENCE; FLUCTUATIONS; TEMPERATURE AB We utilize birefringence and neutron scattering to study the statics and kinetics of a pressure-induced order-disorder transition (ODT) in a solvated diblock copolymer. We find that birefringence is an excellent technique to measure the order-disorder transition at high pressure, yielding sharp changes in its intensity at the transition. Small-angle neutron scattering exhibits a corresponding change in the width of the scattering peak at the ODT. Both techniques indicate a nearly Linear increase of the ODT temperature as a function of pressure. The combination of pressure as a controlling thermodynamic variable and birefringence as the measurement tool permits short time scale kinetics experiments. We find the time scale of the disordering process to be significantly shorter than the ordering time, as revealed by profound asymmetries in the response of the system upon pressurization compared with depressurization. Disordering times as small as 0.5 s are observed in rapid pressure drop experiments. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Migler, KB (reprint author), Natl Inst Stand & Technol, Div Polymers, Bldg 224,Room B210, Gaithersburg, MD 20899 USA. NR 35 TC 15 Z9 15 U1 2 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 27 PY 1998 VL 31 IS 2 BP 360 EP 365 DI 10.1021/ma971295c PG 6 WC Polymer Science SC Polymer Science GA YU590 UT WOS:000071733100019 ER PT J AU Feng, Y Karim, A Weiss, RA Douglas, JF Han, CC AF Feng, Y Karim, A Weiss, RA Douglas, JF Han, CC TI Control of polystyrene film dewetting through sulfonation and metal complexation SO MACROMOLECULES LA English DT Article ID THIN POLYMER-FILMS; VISCOELASTIC BEHAVIOR; LIQUID-FILMS; SURFACES; IONOMERS; RUPTURE; INSTABILITIES; MONOLAYERS; LAYERS AB The dewetting of low molecular weight sulfonated polystyrene ionomers (SPS) on inorganic silicon oxide substrates is compared with unmodified polystyrene (PS, M-w, = 4000) using a combination of X-ray reflectivity, optical and atomic force microscopy. The amounts of sulfonate group and metal counterion (Li-, Zn2+) were both varied in our study. Unlike unmodified PS, which readily dewets the substrate, a strong inhibition of dewetting occurs for low sulfonation (congruent to 2.3 mol %)!, and no apparent dewetting was found for high sulfonation !(greater than or equal to 7 mol %). For ZnSPS, dewetting was not observed in any of the films, even for those with very low sulfonation. Comparison with bulk rheological data suggests that inter-and intramolecular ionomer complexation may be important in retarding the dewetting process (a nonequilibrium effect), in addition to an increased wettability arising from long-range electrostatic polymer-surface interactions. C1 Univ Connecticut, Inst Mat Sci, Storrs, CT 06269 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Univ Connecticut, Inst Mat Sci, Storrs, CT 06269 USA. NR 45 TC 67 Z9 68 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD JAN 27 PY 1998 VL 31 IS 2 BP 484 EP 493 DI 10.1021/ma9706541 PG 10 WC Polymer Science SC Polymer Science GA YU590 UT WOS:000071733100036 ER PT J AU Shirley, EL AF Shirley, EL TI Ab initio inclusion of electron-hole attraction: Application to x-ray absorption and resonant inelastic x-ray scattering SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEXAGONAL BORON-NITRIDE; BAND-STRUCTURE; CORE EXCITON; GRAPHITE; DIAMOND; MODEL; FLUORESCENCE; EDGE AB This work demonstrates a numerically feasible, yet realistic, calculational method for incorporating electron-core-hole interactions (core-hole effects) in the Bethe-Salpeter equation in solids, without recourse to tight-binding or analogous basis-set approximations. The method includes ab initio treatments of separate electron and hole dynamics and electron-hole interactions. The method is used to treat x-ray absorption (XAS), resonant inelastic x-ray scattering (RIXS), and core-hold excitons. Materials studied include LiF, NaF, KF, graphite, diamond, and h-BN. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Shirley, EL (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 27 TC 159 Z9 159 U1 2 U2 25 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 JAN 26 PY 1998 VL 80 IS 4 BP 794 EP 797 DI 10.1103/PhysRevLett.80.794 PG 4 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100038 ER EF