FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Zimmerman, NM Huber, WH Fujiwara, A Takahashi, Y AF Zimmerman, NM Huber, WH Fujiwara, A Takahashi, Y TI Excellent charge offset stability in a Si-based single-electron tunneling transistor SO APPLIED PHYSICS LETTERS LA English DT Article ID 1/F NOISE; DEVICES AB We have measured the long-term drift and the short-term 1/f noise in the charge offset Q(0)(t) in two Si-based single-electron tunneling transistors (SETTs). In contrast to metal-based SETTs, these devices show excellent charge stability, drifting by less than 0.01e over weeks. The short-term 1/f noise magnitude is similar to the metal-based devices, demonstrating that different mechanisms are responsible for the short-term noise versus the long-term drift. Finally, we show that, in addition to the excellent stability over time, it may be possible to make the devices more robust with respect to voltage-induced instability as well. (C) 2001 American Institute of Physics. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NTT Corp, NTT Basic Res Labs, Atsugi, Kanagawa 2430198, Japan. RP Zimmerman, NM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Takahashi, Yasuo/H-4799-2011; Fujiwara, Akira/A-6648-2012 NR 15 TC 55 Z9 56 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 5 PY 2001 VL 79 IS 19 BP 3188 EP 3190 DI 10.1063/1.1415776 PG 3 WC Physics, Applied SC Physics GA 487UY UT WOS:000171896600058 ER PT J AU Feder, DL Clark, CW AF Feder, DL Clark, CW TI Superfluid-to-solid crossover in a rotating Bose-Einstein condensate SO PHYSICAL REVIEW LETTERS LA English DT Article ID GAS AB The properties of a rotating Bose-Einstein condensate confined in a prolate cylindrically symmetric trap are explored both analytically and numerically. As the rotation frequency increases, an ever greater number of vortices are energetically favored. Though the cloud anisotropy and moment of inertia approach those of a classical fluid at high frequencies, the observed vortex density is consistently lower than the solid-body estimate. Furthermore, the vortices are found to arrange themselves in highly regular triangular arrays, with Little distortion even near the condensate surface. These results are shown to be a direct consequence of the inhomogeneous confining potential. C1 Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NIST, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RP Feder, DL (reprint author), Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 22 TC 35 Z9 35 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 5 PY 2001 VL 87 IS 19 AR 190401 DI 10.1103/PhysRevLett.87.190401 PG 4 WC Physics, Multidisciplinary SC Physics GA 490AT UT WOS:000172027200001 PM 11690400 ER PT J AU Nugent-Glandorf, L Scheer, M Samuels, DA Mulhisen, AM Grant, ER Yang, XM Bierbaum, VM Leone, SR AF Nugent-Glandorf, L Scheer, M Samuels, DA Mulhisen, AM Grant, ER Yang, XM Bierbaum, VM Leone, SR TI Ultrafast time-resolved soft x-ray photoelectron spectroscopy of dissociating Br-2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-ORDER HARMONICS; DYNAMICS; SPECTRA; LASER AB The dissociation of excited state Br-2 is probed with the novel technique of ultrafast soft x-ray photoelectron spectroscopy. Excited Br-2 molecules are prepared in the dissociative (1)Pi (u) state with 80 fs, 400 nm pulses, and a series of photoelectron spectra are obtained during dissociation with pulses of soft x-ray light (47 nm, 26.4 eV, 250 fs). The formation of Br atoms is readily detected and the data support an extremely fast dissociation time for Br-2 on the order of 40 fs. Amplitudes of the pump-probe features reveal that the ionization cross section of atomic Br at 47 nm is similar to 40 times larger than that of Br-2. C1 Univ Colorado, Joint Inst Lab Astrophys, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Dept Phys, Boulder, CO 80309 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. Acad Sinica, Inst Atom & Mol Sci, Taipei, Taiwan. RP Nugent-Glandorf, L (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Natl Inst Stand & Technol, Boulder, CO 80309 USA. RI Yang, Xueming/C-8764-2013; OI NUGENT-GLANDORF, LORA/0000-0002-5851-4202 NR 21 TC 113 Z9 113 U1 5 U2 30 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 5 PY 2001 VL 87 IS 19 AR 193002 DI 10.1103/PhysRevLett.87.193002 PG 4 WC Physics, Multidisciplinary SC Physics GA 490AT UT WOS:000172027200009 PM 11690408 ER PT J AU Vakhtin, AB Heard, DE Smith, IWM Leone, SR AF Vakhtin, AB Heard, DE Smith, IWM Leone, SR TI Kinetics Of C2H radical reactions with ethene, propene and 1-butene measured in a pulsed Laval nozzle apparatus at T-103 and 296 K SO CHEMICAL PHYSICS LETTERS LA English DT Article ID TEMPERATURE RATE COEFFICIENTS; CROSSED-BEAM REACTION; HYDROCARBON MOLECULES; CHEMICAL-DYNAMICS; CN(X (2)SIGMA(+)); TITANS ATMOSPHERE; CYANO RADICALS; 359 K; SPECTROSCOPY; O-2 AB Low-temperature kinetics of the reactions of C2H radical with ethene (k(1)), propene (k(1)), and 1-butene (k(3)) are studied using a pulsed Laval nozzle supersonic expansion. The C2H decay profiles in the presence of both the alkene reactant and O-2 are monitored by the CH(A(2) Delta) chemiluminescence tracer method. The rate constants k(1), k(2), and k(3) are measured at T = 103 K to be (1.4 +/- 0.4) x 10(-10), (2.4 +/- 0.6) x 10(-10), and (2.6 +/- 0.6) x 10(10) cm(3) molecule(-1) s(-1), respectively. Measurements at room temperature (296 K) and previous data suggest a slight negative temperature dependence for all three reactions. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Leone, SR (reprint author), Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. OI Heard, Dwayne/0000-0002-0357-6238 NR 24 TC 45 Z9 45 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 2 PY 2001 VL 348 IS 1-2 BP 21 EP 26 DI 10.1016/S0009-2614(01)00975-7 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 490YQ UT WOS:000172081600005 ER PT J AU Ostashev, VE Wilson, DK AF Ostashev, VE Wilson, DK TI Log-amplitude and phase fluctuations of a plane wave propagating through anisotropic, inhomogeneous turbulence SO ACUSTICA LA English DT Article; Proceedings Paper CT Workshop on Tomography and Acoustic - Recent Development and Methods CY MAR 06-07, 2001 CL UNIV LEIPZIG, LEIPZIG, GERMANY HO UNIV LEIPZIG ID SURFACE-LAYER TURBULENCE; SOUND AB The correlation functions and variances of log-amplitude and phase fluctuations are important statistical characteristics of a plane sound wave propagating in a turbulent medium. For line-of-sight sound propagation through isotropic, homogeneous turbulence with temperature and velocity fluctuations, formulas for these correlation functions and variances are given in [V. E. Ostashev: Acoustics in Moving Inhomogeneous Media, E&FN SPON, London, 1997]. In the present paper, starting from the parabolic equation for a sound field and using the Rytov method and Markov approximation, we derive more general formulas for the correlation functions and variances of log-amplitude and phase fluctuatins of a plane sound wave propagating through anisotropic, inhomogeneous turbulence. The effects of turbulence anisotropy and inhomogeneity on these correlation functions and variances are studied numerically with the use of Mann's spectrum for shear-produced, atmospheric turbulence. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. USA, Res Lab, Adelphi, MD 20783 USA. RP Ostashev, VE (reprint author), NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. RI Wilson, D. Keith/A-4687-2012 OI Wilson, D. Keith/0000-0002-8020-6871 NR 12 TC 6 Z9 6 U1 0 U2 1 PU S HIRZEL VERLAG PI STUTTGART PA POSTFACH 10 10 61, D-70 009 STUTTGART, GERMANY SN 0001-7884 J9 ACUSTICA JI Acustica PD NOV-DEC PY 2001 VL 87 IS 6 BP 685 EP 694 PG 10 WC Acoustics SC Acoustics GA 521VN UT WOS:000173862200007 ER PT J AU Ostashev, VE Clifford, SF Lataitis, R Muschinski, A Fabrikant, AL AF Ostashev, VE Clifford, SF Lataitis, R Muschinski, A Fabrikant, AL TI Amplitude-modulated radio-acoustic sounding SO ACUSTICA LA English DT Article; Proceedings Paper CT Workshop on Tomography and Acoustic - Recent Development and Methods CY MAR 06-07, 2001 CL UNIV LEIPZIG, LEIPZIG, GERMANY HO UNIV LEIPZIG ID TEMPERATURE; TURBULENCE AB Amplitude-modulated radio-acoustic sounding of vertical profiles of temperature in the atmosphere was proposed by A. Fabrikant [Radiophysics and Quantum Electronics 34 No. 1 (1991) 12-17]. Fabrikant discussed a case in which electromagnetic waves are scattered by particles in the atmosphere (aerosol, water drops, etc.). In the present paper, we consider a generalization of this scheme to a case in which electromagnetic waves are scattered by atmospheric turbulence. Using the theory of amplitude-modulated radio-acoustic sounding, and accounting for potentialities of modern clear-air radars and acoustic sources, we estimate that the maximum possible height of this scheme for remote sensing of vertical profiles of temperature is less than or about 100 m. However, the maximum height can be increased in the future as more powerful radars and acoustic sources become available. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. KLA Tencor Corp, Milpitas, CA 95035 USA. RP Ostashev, VE (reprint author), NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. NR 8 TC 4 Z9 4 U1 0 U2 0 PU S HIRZEL VERLAG PI STUTTGART PA POSTFACH 10 10 61, D-70 009 STUTTGART, GERMANY SN 0001-7884 J9 ACUSTICA JI Acustica PD NOV-DEC PY 2001 VL 87 IS 6 BP 717 EP 720 PG 4 WC Acoustics SC Acoustics GA 521VN UT WOS:000173862200011 ER PT J AU Wilson, DK Ziemann, A Ostashev, VE Voronovich, AG AF Wilson, DK Ziemann, A Ostashev, VE Voronovich, AG TI An overview of acoustic travel-time tomography in the atmosphere and its potential applications SO ACUSTICA LA English DT Article; Proceedings Paper CT Workshop on Tomography and Acoustics - Recent Development and Methods CY MAR 06-07, 2001 CL UNIV LEIPZIG, LEIPZIG, GERMANY HO UNIV LEIPZIG ID LARGE-EDDY SIMULATION; CONVECTIVE BOUNDARY-LAYER; SURFACE-LAYER; DOPPLER LIDAR; TURBULENCE; LOCALIZATION; PROPAGATION; AIRCRAFT; PROFILES; ANIMALS AB Acoustic travel-time tomography of the atmosphere has been successfully demonstrated in several field studies during the past decade. This paper discusses potential applications where tomography can provide valuable information on the atmosphere, focusing on four particularly promising ones: (1) imaging the four-dimensional velocity and temperature fields of near-ground flow structures including testing the homogeneity of micro-meteorological measurement sites; (2) using the spatial averaging characteristic of tomography to validate large-eddy simulation closure models; (3) providing data on very stable boundary layers, where current numerical simulations do not work well; and (4) passive localization of sound sources in the atmosphere by accounting for atmospheric refraction and advection. With regard to this fourth application, a new technique is discussed for localization of sound sources with simultaneous reconstruction of the vertical wind and temperature profiles. C1 USA, Res Lab, AMSRL, CI,EP, Adelphi, MD 20783 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Univ Leipzig, Inst Meteorol, D-04103 Leipzig, Germany. NOAA, Environm Technol Lab, Boulder, CO 80305 USA. RP Wilson, DK (reprint author), USA, Res Lab, AMSRL, CI,EP, 2800 Powder Mill Rd, Adelphi, MD 20783 USA. EM dkwilson@arl.army.mil; ziemann@rz.uni-leipzig.de; Vladimir.Ostashev@noaa.gov; Alexander.Voronovich@noaa.gov RI Wilson, D. Keith/A-4687-2012 OI Wilson, D. Keith/0000-0002-8020-6871 NR 46 TC 31 Z9 31 U1 0 U2 1 PU S HIRZEL VERLAG PI STUTTGART PA POSTFACH 10 10 61, D-70 009 STUTTGART, GERMANY SN 0001-7884 J9 ACUSTICA JI Acustica PD NOV-DEC PY 2001 VL 87 IS 6 BP 721 EP 730 PG 10 WC Acoustics SC Acoustics GA 521VN UT WOS:000173862200012 ER PT J AU Levin, PS Tolimieri, N AF Levin, PS Tolimieri, N TI Differences in the impacts of dams on the dynamics of salmon populations SO ANIMAL CONSERVATION LA English DT Article ID PSEUDOREPLICATION; SURVIVAL; DESIGNS; BACI AB Modern concrete dams have devastated fish populations world-wide. However, dams vary greatly in how they are engineered and operated, and thus pose a range of threats to riverine fauna. Understanding the differences in the impacts of dams is critical for setting conservation priorities. We used a modified BACI (before-after-control-impact) sampling design as a means to quantify the effects of dams on spring/summer chinook salmon in two watersheds (Snake and Upper Columbia Rivers) of the Columbia River Basin, USA. The construction of four dams in the Columbia River Basin from 1966 to 1975 allowed us to test the hypothesis that the presence of these dams does not affect the abundance, survival and population growth of chinook salmon. In both the Snake and Upper Columbia Rivers, there was a significant decline from the period before dams were constructed (1959-65) to the period after dams were constructed (1980-90). In the Upper Columbia River, declines in productivity or population performance (measured as recruits per spawner or Ricker function residuals) were greater than in the control region. On the other hand, patterns of fish productivity in the Snake River were similar to those seen in the control region. The disparity between fates of Upper Columbia and Snake River populations points to the differences between regions in current efforts to reduce fish mortality associated with dams. Our analysis suggests that dams in the Upper Columbia River, but not Snake River, are a potential force preventing recovery of endangered salmon populations. C1 NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Seattle, WA 98112 USA. Univ Auckland, Leigh Marine Lab, Warkworth, New Zealand. RP Levin, PS (reprint author), NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 32 TC 28 Z9 28 U1 2 U2 16 PU CAMBRIDGE UNIV PRESS PI PORT CHESTER PA 110 MIDLAND AVE, PORT CHESTER, NY 10573-9863 USA SN 1367-9430 J9 ANIM CONSERV JI Anim. Conserv. PD NOV PY 2001 VL 4 BP 291 EP 299 PN 4 PG 9 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 493EN UT WOS:000172209200002 ER PT J AU Kalinowski, ST Hedrick, PW AF Kalinowski, ST Hedrick, PW TI Inbreeding depression in captive bighorn sheep SO ANIMAL CONSERVATION LA English DT Article ID POPULATIONS; MORTALITY; ISIS AB We estimated the extent of inbreeding depression for juvenile survival in 589 captive-born bighorn sheep, and, unlike an earlier report, found no evidence of significant inbreeding depression. There did not appear to be any overall effect of year of birth, place of birth, subspecies, sex or ancestral inbreeding upon the viability of inbred animals as compared to non-inbred animals. However, for the first few years of data, there was lower survival for inbred than non-inbred offspring. After this period, there was an increase in the viability of inbred offspring, probably reflecting a general improvement in husbandry conditions in the zoos. It should be emphasized that the lack of significant inbreeding depression does not necessarily imply that there may not be inbreeding depression for other traits or in a less benign or more natural environment for juvenile viability. C1 Arizona State Univ, Dept Biol, Tempe, AZ 85287 USA. Natl Marine Fisheries Serv, Conservat Biol Div, Seattle, WA 98112 USA. RP Hedrick, PW (reprint author), Arizona State Univ, Dept Biol, Tempe, AZ 85287 USA. EM philip.hedrick@asu.edu RI Kalinowski, Steven/A-7607-2008 NR 23 TC 15 Z9 15 U1 2 U2 12 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1367-9430 EI 1469-1795 J9 ANIM CONSERV JI Anim. Conserv. PD NOV PY 2001 VL 4 BP 319 EP 324 PN 4 PG 6 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 493EN UT WOS:000172209200005 ER PT J AU Germer, TA AF Germer, TA TI Large-angle in-plane light scattering from rough surfaces: comment SO APPLIED OPTICS LA English DT Article AB A recent paper by Karabacak et al. [Appl, Opt. 39,4658 (2000)], which discussed the scattering from rough surfaces in directions out of the plane of incidence, exhibited an error in the derivation of a polarization factor. An asymmetry in the scattering function for directions out of the plane of incidence and for circularly polarized incident light is predicted by the correct derivation of this factor and can be observed in their data. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. EM thomas.germer@nist.gov NR 5 TC 1 Z9 1 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD NOV 1 PY 2001 VL 40 IS 31 BP 5708 EP 5710 DI 10.1364/AO.40.005708 PG 3 WC Optics SC Optics GA 487BH UT WOS:000171853400018 PM 18364859 ER PT J AU Kelly, NM Fonseca, M Whitfield, P AF Kelly, NM Fonseca, M Whitfield, P TI Predictive mapping for management and conservation of seagrass beds in North Carolina SO AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS LA English DT Article DE seagrass; predictive modelling; geographic information systems; North Carolina ID INDIAN-RIVER-LAGOON; AERIAL-PHOTOGRAPHY; AQUATIC MACROPHYTE; LANDSCAPE ECOLOGY; GIS; DYNAMICS; HABITAT; ENVIRONMENT; PATTERNS; ENERGY AB 1. This research extends techniques of predictive mapping from their application in terrestrial environments to marine landscapes by investigating the relationship between seagrass and hydrodynamics in Core Sound, North Carolina, USA. 2. An empirically derived logistic multiple regression model and a Boolean logic suitability model were used to produce several predictive map products, including: susceptibility of seagrasses to storms, probability of seagrass cover, and suitability of areas for restoration of seagrasses. A visual comparison between these maps and conventional seagrass polygon maps allows for a discussion of 'field' versus 'object' mapping, and the ramifications for management based on different cartographic techniques. 3. The predictive method used here showed that only a small portion (19%) of the seagrass bed in the study area would be expected to have a high probability of seagrass coverage. The majority of the seagrass habitat in the study area was predicted to have less than 50% probability of seagrass cover. In addition, 16% of the nearly 2000 ha of seagrass within the study area were predicted to be highly susceptible to acute storm events. Moreover, using a conservative set of site selection criteria, only 7% of the study area encompassed by seagrass habitat was predicted to have a high probability of successful restoration if injured. 4. This method provides for an inexpensive way to scale-up from high-resolution data to a coarser scale that is often required for conservation and management. Copyright (C) 2001 John Wiley Sons, Ltd. C1 Univ Calif Berkeley, Dept Environm Sci Policy & Management, Ecosyst Sci Div, Berkeley, CA 94720 USA. NOAA, Natl Ocean Serv, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. RP Kelly, NM (reprint author), Univ Calif Berkeley, Dept Environm Sci Policy & Management, Ecosyst Sci Div, 151 Hilgard 3110, Berkeley, CA 94720 USA. NR 52 TC 44 Z9 45 U1 2 U2 27 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1052-7613 J9 AQUAT CONSERV JI Aquat. Conserv.-Mar. Freshw. Ecosyst. PD NOV-DEC PY 2001 VL 11 IS 6 BP 437 EP 451 DI 10.1002/aqc.494 PG 15 WC Environmental Sciences; Marine & Freshwater Biology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 513GD UT WOS:000173368800002 ER PT J AU Bargar, TA Scott, GI Cobb, GP AF Bargar, TA Scott, GI Cobb, GP TI Uptake and distribution of three PCB congeners and endosulfan by developing white leghorn chicken embryos (Gallus domesticus) SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID CHORIOALLANTOIC MEMBRANES; ORGANOCHLORINE CONTAMINANTS; REPRODUCTIVE SUCCESS; GREEN-BAY; EGGS; WISCONSIN; ISLAND AB The distributions of PCB 105, 156, 189, and endosulfan in incubating, maternally exposed. viable white leghorn chicken eggs (Gallus domesticus) were investigated. Hens were subcutaneously injected every 4 days with a mixture of the above chemicals. One group of five eggs was removed from the incubator at each of 9, 14, and 19 days of incubation: dissected into three compartments (embryo, chorioallantoic membrane, and yolk + albumin); weighed; frozen; and then later analyzed for the dosing chemicals. Through 19 days of development (90% of incubation), greater than 70% of the total chemical mass in the whole egg remained within the yolk + albumin, whereas, depending on the chemical. 17% to 30% was absorbed by the embryo and 0.2% to 9% was transported into the chorioallantoic membrane. As a percentage of total PCB mass within the respective compartment, PCB 105 composition in the embryo and chorioallantoic membrane decreased significantly throughout development while PCB 156 and 189 composition increased significantly throughout development. Though endosulfan composition within any of the compartments was highly variable, it did not change significantly during development. The results of this study indicate that the majority of avian chick exposure to contaminants occurs posthatch as the chick continues to utilize the residual yolk. C1 US Dept Commerce, Natl Ocean & Atmospher Adm, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Charleston, SC 29412 USA. Texas Tech Univ, Dept Biol Sci, Inst Environm & Human Hlth, Lubbock, TX 79409 USA. RP Bargar, TA (reprint author), MC7507C US EPA, Ariel Rios Bldg,1200 Penn Ave NW, Washington, DC 20460 USA. NR 18 TC 17 Z9 17 U1 0 U2 4 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD NOV PY 2001 VL 41 IS 4 BP 508 EP 514 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 483YT UT WOS:000171664000014 PM 11598789 ER PT J AU Neuman, JA Gao, RS Fahey, DW Holecek, JC Ridley, BA Walega, JG Grahek, FE Richard, EC McElroy, CT Thompson, TL Elkins, JW Moore, FL Ray, EA AF Neuman, JA Gao, RS Fahey, DW Holecek, JC Ridley, BA Walega, JG Grahek, FE Richard, EC McElroy, CT Thompson, TL Elkins, JW Moore, FL Ray, EA TI In situ measurements of HNO3, NOy, NO, and O-3 in the lower stratosphere and upper troposphere SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE photochemistry; tropopause; CIMS; ACCENT; nitrogen oxides ID ARCTIC LOWER STRATOSPHERE; HYDROGEN RADICALS; OZONE PRODUCTION; AIRCRAFT; PHOTOCHEMISTRY; NITROGEN; PAN; SPECTROMETER; MISSION; ACETONE AB In situ measurements of nitric acid (HNO3), reactive nitrogen (NOgamma), nitric oxide (NO), and ozone (O-3) made in the upper troposphere (UT) and lower stratosphere (LS) between 29 degrees and 33 degreesN latitudes during September 1999 are used to examine NOgamma partitioning and correlations between the measured species in these regions. The fast-response (1 s) HNO3 measurements are acquired with a new autonomous CIMS instrument. In the LS, HNO3 accounts for the majority of NOgamma and the sum of HNO3 and NOx accounts for approximately 90% of NOgamma. In the UT, the sum of HNO3 and NOx varies between 40% and 100% of NOgamma. Both HNO3 and NOgamma are strongly positively correlated with O-3, with larger correlation slopes in the UT than in the LS. In the UT at low values of the quantity (NOgamma-NOx-HNO3) it is uncorrelated with O-3, while at higher values, a positive correlation with O-3 is found. Of these two air mass types, those with higher (NOgamma NOx-HNO3) mixing ratios are likely associated with the presence of peroxyacetyl nitrate (PAN) that is produced by NOx-hydrocarbon chemistry. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Meteorol Serv Canada, Downsview, ON M3H 5T4, Canada. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. RP Neuman, JA (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80305 USA. RI Neuman, Andy/A-1393-2009; Gao, Ru-Shan/H-7455-2013; Ray, Eric/D-5941-2013; Fahey, David/G-4499-2013 OI Neuman, Andy/0000-0002-3986-1727; Ray, Eric/0000-0001-8727-9849; Fahey, David/0000-0003-1720-0634 NR 27 TC 42 Z9 42 U1 1 U2 11 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 NOV PY 2001 VL 35 IS 33 BP 5789 EP 5797 DI 10.1016/S1352-2310(01)00354-5 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 495RV UT WOS:000172354900010 ER PT J AU Widmann, JF Presser, C Leigh, SD AF Widmann, JF Presser, C Leigh, SD TI Identifying burst splitting events in phase Doppler interferometry measurements SO ATOMIZATION AND SPRAYS LA English DT Article ID PARTICLE ANALYZER; SPRAY; PERFORMANCE; SIZE AB Burst splitting events, in which noisy environments result in a single droplet being counted as multiple droplets during phase Doppler interferometry (PDI) measurements, are investigated. The cause of burst splitting is discussed and compared with; chattering, another phenomenon that results in overcounting of droplets in PDI measurements. Several techniques are presented to identify the occurrence of burst splitting events, and the impact of such events on the measurements is discussed. It is shown that burst splitting has a serious effect on volume flux measurements; however, the impact on size and velocity distributions is much weaker. The events significantly distort the probe volume correction, which is applied to the measured size distributions to remove the bias introduced by the size dependence of the probe area. Burst splitting events do not depend on the type of PDI processor used; however, it is shown that for frequency-domain processors,judicious choice of operating parameters can minimize the impact of burst splitting occurrences. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Widmann, JF (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 36 TC 5 Z9 5 U1 0 U2 1 PU BEGELL HOUSE INC PI REDDING PA 50 CROSS HIGHWAY, REDDING, CT 06896 USA SN 1044-5110 J9 ATOMIZATION SPRAY JI Atom. Sprays PD NOV-DEC PY 2001 VL 11 IS 6 BP 711 EP 733 PG 23 WC Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 550FC UT WOS:000175492100007 ER PT J AU Bezrukov, SM Kasianowicz, JJ AF Bezrukov, SM Kasianowicz, JJ TI Neutral polymers in the nanopores of alamethicin and alpha-hemolysin SO BIOLOGICHESKIE MEMBRANY LA English DT Article ID SINGLE-ION CHANNEL; PORE; MEMBRANES; CONDUCTANCE; STATES AB The ability of polymers to enter nanometer-scale pores can be probed by ionic channel conductance measurements because the movement of neutral polymer (e.g. poly(ethylene glycol), PEG) into the channel displaces ions and reduces their mobility in the pore. Both result in a reduction of the channel's conductance. Therefore, the state of occupancy of the pore by polymer is reflected by the conductance which we use to determine the polymer partition coefficient. We conclude that the available theoretical approaches to the entropic interaction between polymer and a pore (hard spheres, random flight model, and scaling theory) do not describe the equilibrium partitioning of PEG into alamethicin and a-hemolysin. The empirically obtained partition coefficients for these two channels demonstrate a much sharper dependence on polymer molecular weight. C1 NICHHD, NIH, Lab Phys & Struct Biol, Bethesda, MD 20892 USA. St Petersburg Nucl Phys Inst, Gatchina 188350, Russia. NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Bezrukov, SM (reprint author), NICHHD, NIH, Lab Phys & Struct Biol, Bethesda, MD 20892 USA. NR 22 TC 7 Z9 7 U1 0 U2 2 PU MEZHDUNARODNAYA KNIGA PI MOSCOW PA 39 DIMITROVA UL., 113095 MOSCOW, RUSSIA SN 0233-4755 J9 BIOL MEMBRANY JI Biol. Membr. PD NOV-DEC PY 2001 VL 18 IS 6 BP 453 EP 457 PG 5 WC Cell Biology SC Cell Biology GA 522BE UT WOS:000173875200005 ER PT J AU Angevine, WM Baltink, HK Bosveld, FC AF Angevine, WM Baltink, HK Bosveld, FC TI Observations of the morning transition of the convective boundary layer SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE Cabauw tower; convective boundary layer; Flatland Atmospheric Observatory; morning transition; wind profiler ID ENTRAINMENT ZONE; MIXED-LAYER; PROFILER; DYNAMICS; HEIGHT; MODELS; GROWTH AB The morning transition between the stable nocturnal situation and the daytime convective boundary layer (CBL) is of interest both for basic understanding and for initializing prognostic models. While the morning growth phase of the CBL has been studied in detail, relatively little has been published on the transition itself. In this paper, conventional observations of surface temperature, humidity, and turbulent fluxes, and data from a meteorological tower, are combined with measurements of the onset of convection by boundary-layer wind profilers to explore the timing and behaviour of the transition period. The transition is defined here as the period between sunrise and the time at which the depth of convection reaches about 200 m AGL. Diagnostic relationships based on surface heat flux, the temperature difference between 2 m and 200 m, and bulk Richardson number are explored. The transition is found to be enabled by surface heating relaxing the surface stability, while the warming of the layer between 2 m and 200 m is in large part due to shear-driven entrainment. C1 Univ Colorado, CIRES, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Royal Netherlands Meteorol Inst KNMI, De Bilt, Netherlands. RP Angevine, WM (reprint author), Univ Colorado, CIRES, Boulder, CO 80309 USA. RI Angevine, Wayne/H-9849-2013 OI Angevine, Wayne/0000-0002-8021-7116 NR 19 TC 46 Z9 46 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 NOV PY 2001 VL 101 IS 2 BP 209 EP 227 DI 10.1023/A:1019264716195 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 479HA UT WOS:000171397900004 ER PT J AU Blackmon, M Boville, B Bryan, F Dickinson, R Gent, P Kiehl, J Moritz, R Randall, D Shukla, J Solomon, S Bonan, G Doney, S Fung, I Hack, J Hunke, E Hurrell, J Kutzbach, J Meehl, J Otto-Bliesner, B Saravanan, R Schneider, EK Sloan, L Spall, M Taylor, K Tribbia, J Washington, W AF Blackmon, M Boville, B Bryan, F Dickinson, R Gent, P Kiehl, J Moritz, R Randall, D Shukla, J Solomon, S Bonan, G Doney, S Fung, I Hack, J Hunke, E Hurrell, J Kutzbach, J Meehl, J Otto-Bliesner, B Saravanan, R Schneider, EK Sloan, L Spall, M Taylor, K Tribbia, J Washington, W TI The Community Climate System Model SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID OCEAN CIRCULATION MODELS; SEA-ICE DYNAMICS; SHORTWAVE ABSORPTION; ATMOSPHERIC MODEL; DOWNWARD CONTROL; NATIONAL CENTER; VERSION 3; SIMULATIONS; SURFACE; FLUXES AB The Community Climate System Model (CCSM) has been created to represent the principal components of the climate system and their interactions. Development and applications of the model are carried out by the U.S. climate research community, thus taking advantage of both wide intellectual participation and computing capabilities beyond those available to most individual U.S. institutions. This article outlines the history of the CCSM, its current capabilities, and plans for its future development and applications, with the goal of providing a summary useful to present and future users. The initial version of the CCSM included atmosphere and ocean general circulation models, a land surface model that was grafted onto the atmosphere model, a sea-ice model, and a "flux coupler" that facilitates information exchanges among the component models with their differing grids. This version of the model produced a successful 300-yr simulation of the current climate without artificial flux adjustments. The model was then used to perform a coupled simulation in which the atmospheric CO2 concentration increased by 1% per year. In this version of the coupled model, the ocean salinity and deep-ocean temperature slowly drifted away from observed values, A subsequent correction to the roughness length used for sea ice significantly reduced these errors. An updated version of the CCSM was used to perform three simulations of the twentieth century's climate, and several projections of the climate of the twenty-first century, The CCSM's simulation of the tropical ocean circulation has been significantly improved by reducing the background vertical diffusivity and incorporating an anisotropic horizontal viscosity tensor. The meridional resolution of the ocean model was also refined near the equator. These changes have resulted in a greatly improved simulation of both the Pacific equatorial undercurrent and the surface countercurrents. The interannual variability of the sea surface temperature in the central and eastern tropical Pacific is also more realistic in simulations with the updated model. Scientific challenges to be addressed with future versions of the CCSM include realistic simulation of the whole atmosphere, including the middle and upper atmosphere, as well as the troposphere, simulation of changes in the chemical composition of the atmosphere through the incorporation of an integrated chemistry model; inclusion of global, prognostic biogeochemical components for land, ocean, and atmosphere; simulations of past climates, including times of extensive continental glaciation as well as times with little or no ice; studies of natural climate variability on seasonal-to-centennial timescales; and investigations of anthropogenic climate change. In order to make such studies possible, work is under way to improve all components of the model. Plans call for a new version of the CCSM to be released in 2002. Planned studies with the CCSM will require much more computer power than is currently available. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Ctr Ocean Land Atmosphere Studies, Calverton, MD USA. Univ Wisconsin, Madison, WI USA. Los Alamos Natl Lab, Los Alamos, NM USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. NOAA, Boulder, CO USA. George Mason Univ, Fairfax, VA 22030 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Univ Washington, Seattle, WA 98195 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. RP Blackmon, M (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM blackmon@ncar.ucar.edu RI Doney, Scott/F-9247-2010; C, Y/G-5456-2010; Saravanan, Ramalingam/G-8879-2012; Taylor, Karl/F-7290-2011; Randall, David/E-6113-2011; Bryan, Frank/I-1309-2016; OI Doney, Scott/0000-0002-3683-2437; Saravanan, Ramalingam/0000-0002-0005-6907; Taylor, Karl/0000-0002-6491-2135; Randall, David/0000-0001-6935-4112; Bryan, Frank/0000-0003-1672-8330; Spall, Michael/0000-0003-1966-3122 NR 71 TC 90 Z9 101 U1 1 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 2001 VL 82 IS 11 BP 2357 EP 2376 DI 10.1175/1520-0477(2001)082<2357:TCCSM>2.3.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 488HG UT WOS:000171929700001 ER PT J AU Baldocchi, D Falge, E Gu, LH Olson, R Hollinger, D Running, S Anthoni, P Bernhofer, C Davis, K Evans, R Fuentes, J Goldstein, A Katul, G Law, B Lee, XH Malhi, Y Meyers, T Munger, W Oechel, W U, KTP Pilegaard, K Schmid, HP Valentini, R Verma, S Vesala, T Wilson, K Wofsy, S AF Baldocchi, D Falge, E Gu, LH Olson, R Hollinger, D Running, S Anthoni, P Bernhofer, C Davis, K Evans, R Fuentes, J Goldstein, A Katul, G Law, B Lee, XH Malhi, Y Meyers, T Munger, W Oechel, W U, KTP Pilegaard, K Schmid, HP Valentini, R Verma, S Vesala, T Wilson, K Wofsy, S TI FLUXNET: A new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide, water vapor, and energy flux densities SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Review ID TEMPERATE DECIDUOUS FOREST; FREQUENCY-RESPONSE CORRECTIONS; LONG-TERM MEASUREMENTS; SURFACE-AIR EXCHANGE; SENSIBLE HEAT FLUXES; BOREAL ASPEN FOREST; LEAF-AREA INDEX; ATMOSPHERIC CO2; TERRESTRIAL ECOSYSTEMS; TALL VEGETATION AB FLUXNET is a global network of micrometeorological flux measurement site's that measure the exchanges of carbon dioxide, water vapor, and energy between the biosphere and atmosphere. At present over 140 sites are operating on a long-term and continuous basis. Vegetation under study includes temperate conifer and broadleaved (deciduous and evergreen) forests, tropical and boreal forests, crops, grasslands, chaparral, wetlands, and tundra. Sites exist on five continents and their latitudinal distribution ranges from 70 degreesN to 30 degreesS. FLUXNET has several primary functions. First, it provides infrastructure for compiling, archiving, and distributing carbon, water, and energy flux measurement, and meteorological, plant, and soil data to the science community. (Data and site information are available online at the FLUXNET Web site, http://www-eosdis.oml.gov/FLUXNTET/.) Second, the project supports calibration and flux intercomparison activities. This activity ensures that data from the regional networks are intercomparable. And third, FLUXNET supports the synthesis, discussion, and communication of ideas and data by supporting project scientists, workshops, and visiting scientists. The overarching goal is to provide information for validating computations of net primary productivity, evaporation, and energy absorption that are being generated by sensors mounted on the NASA Terra satellite. Data being compiled by FLUXNET are being used to quantify and compare magnitudes and dynamics of annual ecosystem carbon and water balances, to quantify the response of stand-scale carbon dioxide and water vapor flux densities to controlling biotic and abiotic factors, and to validate a hierarchy of soil-plant-atmosphere trace gas exchange models. Findings so far include 1) net CO2 exchange of temperate broadleaved forests increases by about 5.7 a C m(-2) day(-1) for each additional day that the growing season is extended; 2) the sensitivity of net ecosystem CO2 exchange to sunlight doubles if the sky is cloudy rather than clear; 3) the spectrum of CO2 flux density exhibits peaks at timescales of days, weeks, and years, and a spectral gap exists at the month timescale. 4) the optimal temperature of net CO2 exchange varies with mean summer temperature; and 5) stand age affects carbon dioxide and water vapor flux densities. C1 Univ Calif Berkeley, Dept Environm Sci Policy & Management, Ecosyst Sci Div, ESPM, Berkeley, CA 94720 USA. Univ Bayreuth, Bayreuth, Germany. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. US Forest Serv, USDA, Durham, NH USA. Univ Montana, Sch Forestry, Missoula, MT 59812 USA. Oregon State Univ, Corvallis, OR 97331 USA. Tech Univ Dresden, IHM Meteorol, Tharandt, Germany. Penn State Univ, Dept Meteorol, University Pk, PA USA. Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA. Duke Univ, Sch Environm, Durham, NC USA. Yale Univ, Sch Forestry, New Haven, CT USA. Univ Edinburgh, Inst Ecol & Resource Management, Edinburgh, Midlothian, Scotland. NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. San Diego State Univ, Dept Biol, San Diego, CA 92182 USA. Univ Calif Davis, Davis, CA 95616 USA. Risoe Natl Lab, Plant Biol & Biogeochem Dept, Roskilde, Denmark. Indiana Univ, Dept Geog, Bloomington, IN 47405 USA. Univ Tuscia, DISAFRI, Viterbo, Italy. Univ Nebraska, Sch Nat Resource Sci, Lincoln, NE USA. Univ Helsinki, Dept Phys, Helsinki, Finland. RP Baldocchi, D (reprint author), Univ Calif Berkeley, Dept Environm Sci Policy & Management, Ecosyst Sci Div, ESPM, 151 Hilgard Hall, Berkeley, CA 94720 USA. RI Gu, Lianhong/H-8241-2014; Katul, Gabriel/A-7210-2008; Baldocchi, Dennis/A-1625-2009; Oechel, Walter/F-9361-2010; Goldstein, Allen/A-6857-2011; Valentini, Riccardo/D-1226-2010; Hollinger, David/G-7185-2012; Schmid, Hans Peter/I-1224-2012; Pilegaard, Kim/I-7137-2013; Meyers, Tilden/C-6633-2016; Vuichard, Nicolas/A-6629-2011; Munger, J/H-4502-2013; Vesala, Timo/C-3795-2017 OI Law, Beverly/0000-0002-1605-1203; Gu, Lianhong/0000-0001-5756-8738; Katul, Gabriel/0000-0001-9768-3693; Baldocchi, Dennis/0000-0003-3496-4919; Oechel, Walter/0000-0002-3504-026X; Goldstein, Allen/0000-0003-4014-4896; Valentini, Riccardo/0000-0002-6756-5634; Schmid, Hans Peter/0000-0001-9076-4466; Pilegaard, Kim/0000-0002-5169-5717; Munger, J/0000-0002-1042-8452; Vesala, Timo/0000-0002-4852-7464 NR 103 TC 1623 Z9 1769 U1 50 U2 451 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 2001 VL 82 IS 11 BP 2415 EP 2434 DI 10.1175/1520-0477(2001)082<2415:FANTTS>2.3.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 488HG UT WOS:000171929700004 ER PT J AU Garcia, RR Diaz, HF Herrera, RG Eischeid, J Prieto, MD Hernandez, E Gimeno, L Duran, FR Bascary, AM AF Garcia, RR Diaz, HF Herrera, RG Eischeid, J Prieto, MD Hernandez, E Gimeno, L Duran, FR Bascary, AM TI Atmospheric circulation changes in the tropical Pacific inferred from the voyages of the Manila galleons in the sixteenth-eighteenth centuries SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID INDIAN MONSOON; ENSO AB Historical accounts of the voyages of the Manila galleons derived from the Archivo General de Indias (General Archive of the Indies, Seville, Spain) are used to infer past changes in the atmospheric circulation of the tropical Pacific Ocean. It is shown that the length of the voyage between Acapulco, Mexico, and the Philippine Islands during the period 1590-1750 exhibits large secular trends, such that voyages in the middle of the seventeenth century are some 40% longer than those at the beginning or at the end of the century, and that these trends are unlikely to have been caused by societal or technological factors. Analysis of a series of "virtual voyages," constructed from modem wind data,,indicates that sailing time to the Philippines depended critically on the strength of the trade winds and the position of the western Pacific monsoon trough. These results suggest that the atmospheric circulation of the western Pacific underwent large, multidecadal fluctuations during the seventeenth century. C1 Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. NOAA, Climate Diagnost Ctr, Boulder, CO USA. Univ Complutense, E-28040 Madrid, Spain. CRICYT, Mendoza, Argentina. Univ Vigo, Orense, Spain. Univ Sevilla, Seville, Spain. RP Garcia, RR (reprint author), Natl Ctr Atmospher Res, Div Atmospher Chem, POB 3000, Boulder, CO 80307 USA. RI GIMENO, LUIS/B-8137-2008; OI GARCIA HERRERA, RICARDO FRANCISCO/0000-0002-3845-7458 NR 26 TC 28 Z9 29 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 2001 VL 82 IS 11 BP 2435 EP 2455 DI 10.1175/1520-0477(2001)082<2435:ACCITT>2.3.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 488HG UT WOS:000171929700005 ER PT J AU DeLong, AK Collie, JS Meise, CJ Powell, JC AF DeLong, AK Collie, JS Meise, CJ Powell, JC TI Estimating growth and mortality of juvenile winter flounder, Pseudopleuronectes americanus, with a length-based model SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID OF-THE-YEAR; NARRAGANSETT-BAY; PLEURONECTES-AMERICANUS; POPULATION-MODEL; RHODE-ISLAND; FISH; AGE; ABUNDANCE; ESTUARIES; DYNAMICS AB This study quantifies the combined effects of density and environmental factors on young-of-the-year (YOY) winter flounder (Pseudopleuronectes americanus) in Narragansett Bay, Rhode Island. We used a length-based model to estimate growth and mortality rates from June to October each year from 1988 to 1998. In this model, mortality and growth rates are decreasing functions of length and there is variability in individual growth. Maximum-likelihood methods were used to fit the model to length-frequency data collected by the Rhode Island Division of Fish and Wildlife beach-seine survey in Narragansett Bay during the study years. The monthly mortality rate was density dependent and was positively related to temperature. Growth rate was negatively related to density. There was a significant decline in YOY winter flounder abundance during the period of study. The most recent year of the study, 1998, had the lowest density, lowest mortality, low summer temperature, and high growth rate. Thus, growth and mortality during the juvenile stage do not appear to be limiting the recovery of this depleted winter flounder population. C1 Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. NOAA, NMFS, James J Howard Marine Sci Ctr, Highlands, NJ 07732 USA. Rhode Isl Div Fish & Wildlife, Wickford Marine Fisheries Off, Wickford, RI 02852 USA. RP DeLong, AK (reprint author), Univ Rhode Isl, Grad Sch Oceanog, S Ferry Rd, Narragansett, RI 02882 USA. NR 37 TC 19 Z9 20 U1 0 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD NOV PY 2001 VL 58 IS 11 BP 2233 EP 2246 DI 10.1139/cjfas-58-11-2233 PG 14 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 494DP UT WOS:000172266700014 ER PT J AU Chen, RJ Greenblatt, M Bendersky, LA AF Chen, RJ Greenblatt, M Bendersky, LA TI Stabilization of the n=3 Ruddlesden-Popper phases: Sr4Mn3-xFexO10-delta and Sr4-yCayMn3O10-delta SO CHEMISTRY OF MATERIALS LA English DT Article ID MAGNETIC-PROPERTIES; PEROVSKITES; MANGANITES; COMPOUND; LA AB Sr4Mn3O10, which crystallizes in space group Cmca, is not a Ruddlesden-Popper (RP) phase. The partial substitution of either Mn by Fe or Sr by Ca leads to a stable n = 3 RP phase with tetragonal symmetry (I4/mmm). The minimum amount of Fe or Ca needed to obtain a stable RP phase is x = 0.40 for Sr4Mn3-xFexO10-delta and y = 2.85 for Sr4-yCayMn3O10-delta. High-resolution transmission electron microscopy and selected area electron diffraction electron microscopy indicate that about 50% of the grains have well-ordered n = 3 structure for both series of RP phases, while the rest of the grains show significant intergrowth between the n = 2 and n = 3 structures. Sr4Mn2.6Fe0.4O10-delta and Sr1.15Ca2.85Mn3O10-delta are semiconductors and exhibit spin-glass like transitions at low temperature. C1 Rutgers State Univ, Dept Chem, Piscataway, NJ 08854 USA. NIST, Div Met, Gaithersburg, MD 20899 USA. RP Greenblatt, M (reprint author), Rutgers State Univ, Dept Chem, POB 939, Piscataway, NJ 08854 USA. EM greenblatt@rutchem.rutgers.edu NR 22 TC 8 Z9 8 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD NOV PY 2001 VL 13 IS 11 BP 4094 EP 4100 DI 10.1021/cm0102842 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 495CY UT WOS:000172323700048 ER PT J AU Rust, BW AF Rust, BW TI Fitting nature's basic functions Part II: Estimating uncertainties and testing hypotheses SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Rust, BW (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8910, Gaithersburg, MD 20899 USA. NR 3 TC 7 Z9 7 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD NOV-DEC PY 2001 VL 3 IS 6 BP 60 EP 64 DI 10.1109/5992.963429 PG 5 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 483UU UT WOS:000171654900010 ER PT J AU Bruckner, AW Bruckner, RJ AF Bruckner, AW Bruckner, RJ TI Condition of restored Acropora palmata fragments off Mona Island, Puerto Rico, 2 years after the Fortuna Reefer ship grounding SO CORAL REEFS LA English DT Article DE Habitat restoration; coral reef; Acropora palmata; Elkhorn coral; ship grounding ID ASEXUAL RECRUITS; CORALS; PATTERNS; GROWTH; SCLERACTINIA; COMMUNITIES; STRATEGIES; ABUNDANCE; SURVIVAL AB Acorpora palmata fragments generated by the Fortuna Reefer ship grounding (1997, Mona Island, Puerto Rico) were secured to reef substrate and to dead, standing A. palmata skeletons using stainless-steel wire (n = 1,857). The purpose of this study was to assess fragment survivorship and condition 2 years after the attachment of fragments (26%) and 17% were missing, mostly from shallow water. Live fragments had tissue covering 52% of upper branch surfaces; 23% of the live fragments experienced little or no tissue loss; 27% exhibited proto-branches; 14% had fused to the substrate; and 16% had overgrown the wire. Mortality was attributed to overgrowth by Cliona spp. and macroalgae, predation by Coralliophila abbreviata and Hermodice carunculata, disease, and Stegastes planifrons territories. Limitations associated with the restoration technique include a low ability of coral tissue to over-grow wire and wire corrosion and breakage. Low rates of natural fusion and continued wire failure may hinder long-term recovery as storms periodically detach and remove restored fragments. C1 NOAA, Natl Marine Fisheries Serv, Off Habitat Conservat, Silver Spring, MD 20910 USA. NOAA, Natl Marine Fisheries Serv, Off Protected Resources, Silver Spring, MD 20910 USA. RP Bruckner, RJ (reprint author), NOAA, Natl Marine Fisheries Serv, Off Habitat Conservat, 1315 E W Highway, Silver Spring, MD 20910 USA. NR 32 TC 36 Z9 45 U1 4 U2 16 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD NOV PY 2001 VL 20 IS 3 BP 235 EP 243 PG 9 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 499FR UT WOS:000172560800007 ER PT J AU Sluka, RD Miller, MW AF Sluka, RD Miller, MW TI Herbivorous fish assemblages and herbivory pressure on Laamu Atoll, Republic of Maldives SO CORAL REEFS LA English DT Article DE herbivory; herbivorous fishes; assemblage structure; Maldives ID GREAT-BARRIER-REEF; EPILITHIC ALGAL COMMUNITY; REUNION FRINGING REEFS; CORAL-REEF; INDIAN-OCEAN; GRAZING FISHES; SEA-URCHINS; MID-SHELF; DYNAMICS; ABUNDANCE AB While herbivory is recognized as a fundamental process structuring coral reef communities, herbivore assemblages and processes are poorly described for reefs in the Indian Ocean region. We quantified herbivorous fish assemblage structure (abundance and diversity) in Laamu Atoll, Republic of Maldives, in four reef habitat types: faro reef flats, faro reef slopes, inner and outer atoll reef slopes (20 sites in total). Herbivorous fish assemblages, representing a total of 30 species, grouped strongly by habitat type, with the highest absolute abundance observed on faro reef flats and lowest abundance on inside atoll rim reef slopes. Removal of Thalassia seagrass blades by ambient herbivore assemblages was used in a bioassay to assess relative herbivory pressure among four habitat types (eight sites). Also, at one site a choice herbivory assay was performed to assess herbivore preference among four benthic plants across three depth zones. Relative herbivory, as indicated by Thalassia assays, was highest on inside atoll rim reef slopes and lowest on outside atoll rim reef slopes. Thalassia consumption did not correspond to overall herbivorous fish abundance, but corresponded more closely with parrotfish abundance. In the choice assays, herbivores showed strong preferences among plant types and consumption of most plant types was higher at mid-depth than in the shallow reef flat or deep reef knoll zones. C1 Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Miami, FL 33149 USA. Oceanog Soc Maldives, Male, Maldives. RP Miller, MW (reprint author), Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Miami, FL 33149 USA. NR 39 TC 17 Z9 19 U1 1 U2 10 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD NOV PY 2001 VL 20 IS 3 BP 255 EP 262 DI 10.1007/s003380100166 PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 499FR UT WOS:000172560800011 ER PT J AU Miller, SL Chiappone, M Swanson, DW Ault, JS Smith, SG Meester, GA Luo, J Franklin, EC AF Miller, SL Chiappone, M Swanson, DW Ault, JS Smith, SG Meester, GA Luo, J Franklin, EC TI An extensive deep reef terrace on the Tortugas Bank, Florida Keys National Marine Sanctuary SO CORAL REEFS LA English DT Article ID CORAL C1 Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Miami, FL 33149 USA. RP Miller, SL (reprint author), Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, 75 Virginia Beach Dr, Miami, FL 33149 USA. RI Ault, Jerald/A-5241-2008 OI Ault, Jerald/0000-0001-9657-8007 NR 3 TC 4 Z9 4 U1 0 U2 2 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD NOV PY 2001 VL 20 IS 3 BP 299 EP 300 PG 2 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 499FR UT WOS:000172560800016 ER PT J AU Van Dresar, NT Siegwarth, JD Hasan, MM AF Van Dresar, NT Siegwarth, JD Hasan, MM TI Convective heat transfer coefficients for near-horizontal two-phase flow of nitrogen and hydrogen at low mass and heat flux SO CRYOGENICS LA English DT Article DE space cryogenics; heat transfer; two-phase flow ID GENERAL CORRELATION AB Correlations for convective heat transfer coefficients are reported for two-phase flow of nitrogen and hydrogen under low mass and heat flux conditions. The range of flowrates, heat flux and tube diameter are representative of thermodynamic vent systems (TVSs) planned for propellant tank pressure control in spacecraft operating over long durations in microgravity environments. Experiments were conducted in normal gravity with a 1.5degrees upflow configuration. The Nusselt number exhibits peak values near transition from laminar to turbulent flow based on the vapor Reynolds number. This transition closely coincides with a flow pattern transition front plug to slug flow. The Nusselt number was correlated using components of the Martinelli parameter and a liquid-only Froude number. Separate correlating equations were fitted to the laminar liquid/laminar vapor and laminar liquid/turbulent vapor flow data. The correlations give root-mean-squared (rms) prediction errors within 15%. Published by Elsevier Science Ltd. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Van Dresar, NT (reprint author), NASA, Glenn Res Ctr, MS 86-2, Cleveland, OH 44135 USA. NR 12 TC 5 Z9 5 U1 0 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD NOV-DEC PY 2001 VL 41 IS 11-12 BP 805 EP 811 AR PII S0011-2275(01)00173-4 DI 10.1016/S0011-2275(01)00173-4 PG 7 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA 571NQ UT WOS:000176723800005 ER PT J AU McDonough, WG Antonucci, JM Dunkers, JP AF McDonough, WG Antonucci, JM Dunkers, JP TI Interfacial shear strengths of dental resin-glass fibers by the microbond test SO DENTAL MATERIALS LA English DT Article DE adhesion; microbond test; interface strength; dental resins AB Objective: The aim of this study was to investigate the feasibility of using the microbond test (MBT) to probe the durability of the bond between a polymerized dental resin with differently silanized E-glass fibers. Methods: The E-glass fibers were silanized with equivalent amounts of two types of acrylic-silane coupling agents: 3-methacryloxypropyltrimethoxysilane (MPTMS) and 10-methacryloxydecyltrimethoxysilane (MDTMS), a more hydrophobic silane coupling agent than MPTMS. Unsilanized E-glass fibers were used as the control. Microdroplets of a photo-activated dental resin were applied on the fiber and photocured with visible light irradiation (470 nm). Subsequently, the specimens were tested in shear after 24 h storage in air at 23 degreesC or water at 60 degreesC. Results: The mean interfacial shear strength (tau) and the standard deviation in MPa for the three systems in 23 degreesC in air (n > 7) were: 33.8(10.1), 33.7(8.9) and 15.3(4.2) for the MPTMS silanized, MDTMS silanized. and unsilanized fibers, respectively. When the three types of fibers were first exposed to 60 degreesC water for 24 h prior to having the microdroplets of the resin bonded to them, the strength values of the MDTMS silanized fibers and the control fibers remained essentially unchanged at (n greater than or equal to 7) 31.8(7.7) and 17.5(4.9) MPa respectively; the MPTMS specimens showed a significant decrease to 15.8(4.8) MPa. Similar trends were observed when the fibers had microdroplets of the resin bonded to them prior to aqueous exposure. Significance: These results indicate that the microbond test has the sensitivity to measure changes at the interface between polymerized dental resins and variously silanized E-glass fibers. It appears that surface modification of the fibers with the more hydrophobic silane coupling agent MDTMS promotes enhanced resistance to degradation from exposure to water. The microbond test has the potential for studying dental adhesion involving small bonded areas under a variety of conditions with different adhesive systems and substrates. Published by Elsevier Science Ltd on behalf of Academy of Dental Materials. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP McDonough, WG (reprint author), NIST, Div Polymers, 100 Bur Dr,Stop 8543, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [2Y0 1-DE-30001] NR 15 TC 41 Z9 42 U1 0 U2 9 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 NOV PY 2001 VL 17 IS 6 BP 492 EP 498 DI 10.1016/S0109-5641(01)00008-2 PG 7 WC Dentistry, Oral Surgery & Medicine; Materials Science, Biomaterials SC Dentistry, Oral Surgery & Medicine; Materials Science GA 483KP UT WOS:000171634800004 PM 11567686 ER PT J AU Polissar, AV Hopke, PK Harris, JM AF Polissar, AV Hopke, PK Harris, JM TI Source regions for atmospheric aerosol measured at Barrow, Alaska SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID LONG-TERM DECREASE; SOUTH-POLE; FLOW PATTERNS; ARCTIC HAZE; SULFUR AB Aerosol data consisting of condensation nuclei (CN) counts, black carbon (BC) mass concentration, and aerosol light scattering coefficient at the wavelength of 450 nm (SC) measured at Barrow, AK, from 1986 to 1997 have been analyzed. BC and SIC show an annual cycle with the Arctic haze maxima in the winter and spring and the minima in the summer. The CN time series shows two maxima in March and August, Potential source contribution function (PSCF) that combines the aerosol data with air parcel backward trajectories was applied to identify potential source areas and the preferred pathways that give rise to the observed high aerosol concentrations at Barrow. Ten-day isentropic back trajectories arriving twice daily at 500 and 1500 m above sea level were calculated for the period from 1986 to 1997. The PSCF analyses were performed based on the 80th percentile criterion values for the 2- and 24-h averages of the measured aerosol parameters. There was a good correspondence between PSCF maps for the 2- and 24-h averages, indicating that 1-day aerosol sampling in the Arctic adequately represents the aerosol source areas. In winter, the high PSCF values for BC and SIC are related to industrial source areas in Eurasia. The trajectory domain in winter and spring is larger than in summer, reflecting weaker transport in summer. No high PSCF areas for BC and SIC can be observed in summer. The result is related to the poor transport into the Arctic plus the strong removal of aerosol by precipitation in summer. In contrast to the BC and SC maps, the CN plot for summer shows high PSCF areas in the North Pacific Ocean. High CN values appear to be mostly connected with the long-range transport from Eurasia in winter and spring and with the reduced sulfur compound emission from biogenic activities in the ocean in the summer. PSCF analysis was found to be effective in identifying potential aerosol source areas. C1 Clarkson Univ, Dept Chem Engn, Potsdam, NY 13699 USA. NOAA, RECGI, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Hopke, PK (reprint author), Clarkson Univ, Dept Chem Engn, Potsdam, NY 13699 USA. RI Hopke, Philip/C-6020-2008 OI Hopke, Philip/0000-0003-2367-9661 NR 30 TC 111 Z9 118 U1 4 U2 39 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD NOV 1 PY 2001 VL 35 IS 21 BP 4214 EP 4226 DI 10.1021/es0107529 PG 13 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 489RZ UT WOS:000172006600026 PM 11718334 ER PT J AU Funes-Rodriguez, R Hinojosa-Medina, A Avendano-Ibarra, R Hernandez-Rivas, M Saldierna-Martinez, R Watson, W AF Funes-Rodriguez, R Hinojosa-Medina, A Avendano-Ibarra, R Hernandez-Rivas, M Saldierna-Martinez, R Watson, W TI Spawning of small pelagic fishes in Bahia Magdalena, Baja California Sur, Mexico, at the beginning of the 1997-1998 El Nino event SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE El Nino; eggs and fish larvae; Bahia Magdalena; Mexico ID CURRENT SYSTEM AB A study of the seasonal abundance of planktonic eggs and larvae of small pelagic fishes, and relationships of egg and larval abundances with sea surface temperature and zooplankton biomass in Bahia Magdalena, Baja California Sur, Mexico, a subtropical lagoon, was done during the first year of the 1997-1998 El Nino event. Sardinops caeruleus and Scomber japonicus spawned primarily in winter, when sea surface temperature and zooplankton biomass were lowest (19.8-21.0 degreesC; 100-300 ml 1000 m(-3)), while Anchoa spp. and Opisthonema spp. spawned predominantly in late spring, when the sea surface temperature and zooplankton biomass were increasing to their summer maxima (>21.0 degreesC; >300 ml 1000 m(-3)). During the warm, El Nino years of 1983 and 1997, the egg and larval abundances of Opisthonema spp., a taxon of tropical affinity, increased, while those of Sardinops caeruleus, a transitional, California Current species, diminished drastically. This decline for S. caeruleus probably reflected a shift in the spawning distribution of the adults. Diminished commercial catches during 1997 in Bahia Magdalena, coupled with significantly increased catches in the north, off Ensenada, Baja California, provide supporting evidence. (C) 2001 Academic Press. C1 Inst Politecn Nacl, Ctr Interdisciplinario Ciencias Marinas, La Paz 23000, Baja California, Mexico. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Funes-Rodriguez, R (reprint author), Inst Politecn Nacl, Ctr Interdisciplinario Ciencias Marinas, Apartado Postal 592, La Paz 23000, Baja California, Mexico. OI FUNES-RODRIGUEZ, RENE/0000-0002-6139-0861 NR 41 TC 6 Z9 6 U1 0 U2 1 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0272-7714 J9 ESTUAR COAST SHELF S JI Estuar. Coast. Shelf Sci. PD NOV PY 2001 VL 53 IS 5 BP 653 EP 664 DI 10.1006/ecss.2001.0804 PG 12 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 519WG UT WOS:000173748000004 ER PT J AU Pothoven, SA Fahnenstiel, GL Vanderploeg, HA AF Pothoven, SA Fahnenstiel, GL Vanderploeg, HA TI Population dynamics of Bythotrephes cederstroemii in south-east Lake Michigan 1995-1998 SO FRESHWATER BIOLOGY LA English DT Article DE Bythotrephes cederstroemii; exotic species; Lake Michigan; parthenogenesis; resting egg ID INVERTEBRATE PREDATOR BYTHOTREPHES; CLADOCERAN BYTHOTREPHES; GREAT-LAKES; ZOOPLANKTON COMMUNITY; SPECIES INVASION; NORTH-AMERICAN; FISH COMMUNITY; HARP LAKE; ONTARIO; ABUNDANCE AB 1. Population characteristics (density, size, reproductive patterns) of the predatory cladoceran Bythotrephes cederstroemii in south-east Lake Michigan were monitored at an offshore station (110 m) in 1995-98 and at a nearshore station (45 m) in 1997-98. 2. The mean density of B. cederstroemii at the offshore station was generally highest in July-September (145-914 m(-2)) and at the nearshore station in October-November (168-1625 m(-2)). In 1995 and 1998, density was also high at the offshore station in November (211-284 m(-2)). Fish predation may limit B. cederstroemii in nearshore regions in the summer. The maximum annual densities of B. cederstroemii for 1995-98 were generally similar to those reported from the late 1980s, when the species arrived in Lake Michigan. 3. Body size increased rapidly each year to a maximum in August. Thereafter, body size declined and converged for stage-2 and 3 individuals, suggesting food scarcity or size-selective fish predation was affecting large individuals. 4. Most reproduction occurred asexually (90%), and by stage 2 or 3 females (99%). Asexual brood size was highest when B. cederstroemii first appeared each year, and decreased in August, when larger neonates were produced. There appeared to be differences in reproductive mode for stage 2 and 3 females, with a higher percentage of stage 2 females reproducing sexually. C1 Univ Michigan, Lake Michigan Field Stn, GLERL, Cooperat Inst Limnol & Ecosyst Res, Muskegon, MI 49441 USA. NOAA, Lake Michigan Field Stn, Great Lakes Environm Res Lab, Muskegon, MI USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Pothoven, SA (reprint author), Univ Michigan, Lake Michigan Field Stn, GLERL, Cooperat Inst Limnol & Ecosyst Res, 1431 Beach St, Muskegon, MI 49441 USA. OI Pothoven, Steven/0000-0002-7992-5422; Vanderploeg, Henry/0000-0003-1358-8475 NR 38 TC 18 Z9 18 U1 0 U2 4 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 NOV PY 2001 VL 46 IS 11 BP 1491 EP 1501 DI 10.1046/j.1365-2427.2001.00772.x PG 11 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 495KY UT WOS:000172341400006 ER PT J AU Ramillien, G AF Ramillien, G TI Genetic algorithms for geophysical parameter inversion from altimeter data SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE inverse problem; genetic algorithms; geoid/gravity anomalies ID LEAST-SQUARES INVERSION; ELASTIC THICKNESS; GEOID HEIGHTS; LITHOSPHERE; TOPOGRAPHY; ISLANDS AB A new approach for inverting several geophysical parameters at the same time from altimeter and marine data by implementing genetic algorithms (GAs) is presented. These original techniques of optimization based on non-deterministic rules simulate the evolution of a population of candidate solutions for a given objective function to minimize. They offer a robust and efficient alternative to gradient techniques for non-linear parameter inversion. Here genetic algorithms are used for solving a discrete gravity problem of data associated with an undersea relief, to retrieve seven parameters at the same time: the elastic thickness, the mean ocean depth, the seamount location (longitude/latitude), its amplitude, radius and density from its observed gravity/geoid signature. This approach was also successfully used to adjust lithosphere parameters in the real case of the Rarotonga seamount [21.2 degreesS; 159.8 degreesW] in the Southern Cook Islands region, where GA simulations provided robust estimates of these seven parameters. The GA found very realistic values for the mean ocean depth and the seamount amplitude and the precise geographical location of Rarotonga Island. Moreover, the values of elastic thickness (similar to 14-15 km) and seamount density (similar to 2850-2870 kg m(-3)) estimated by the GA are consistent with the ones proposed in earlier studies. C1 NOAA, Lab Satellite Altimetry, Silver Spring, MD 20910 USA. RP Ramillien, G (reprint author), NOAA, Lab Satellite Altimetry, E1RA31,SSMC3,Room 3620,1315 East West Highway, Silver Spring, MD 20910 USA. NR 26 TC 8 Z9 9 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD NOV PY 2001 VL 147 IS 2 BP 393 EP 402 DI 10.1046/j.0956-540x.2001.01543.x PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 491FZ UT WOS:000172099200013 ER PT J AU Bond, TC AF Bond, TC TI Spectral dependence of visible light absorption by carbonaceous particles emitted from coal combustion SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AMORPHOUS-CARBON; UNITED-STATES; AEROSOLS; SULFATE; CALIBRATION; MATTER AB Optical characteristics of particles that absorb visible light are needed to model their effects on atmospheric radiation. Light absorption by particles emitted from low-technology coal combustion has exhibited a strong spectral dependence. I investigate various explanations for this phenomenon and conclude that a spectrally dependent imaginary refractive index is the most plausible. Following previous work on the structure of amorphous carbon, I propose that both the magnitude and spectral dependence of light absorption axe controlled by the size of graphitic clusters within the material, and can be described using the optical band-gap theory. This hypothesis is an alternative to the current measurement divisions of light-absorbing "black carbon" and non-absorbing "organic carbon," and offers an explanation for preferential absorption at blue wavelengths that may extend to ultraviolet wavelengths. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Bond, TC (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. RI Bond, Tami/A-1317-2013 OI Bond, Tami/0000-0001-5968-8928 NR 33 TC 131 Z9 134 U1 3 U2 44 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 1 PY 2001 VL 28 IS 21 BP 4075 EP 4078 DI 10.1029/2001GL013652 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 485TM UT WOS:000171780000017 ER PT J AU Zhou, ST Miller, AJ Wang, JL Angell, JK AF Zhou, ST Miller, AJ Wang, JL Angell, JK TI Trends of NAO and AO and their associations with stratospheric processes SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NORTH-ATLANTIC OSCILLATION; OZONE DEPLETION; ANNULAR MODES AB Trends of NAO and AO are shown, along with trends of various stratospheric fields and dynamical processes, including geopotential height, temperature and zonal wind, as well as EP flux and its divergence, based upon 30 years (1968-1997) of NCEP/NCAR Reanalysis data. Monthly trends are estimated by using linear regression. The NAO trends are similar to the AO trends in February and March, but different in other months, particularly in May and June. Comparing the variation by month of stratospheric trends with that of the NAO and AO index, we find that the largest trends of stratospheric fields and processes are in the same active season (JFM) as that in NAO and AO, but with the timing of peak of the trends somewhat different, the stratospheric trends leading the NAO and AO trends by one month. We also find a significant trend of equatorward refraction of mid-latitude planetary waves in January. C1 NOAA, Natl Ctr Environm Predict, Camp Springs, MD USA. NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP Zhou, ST (reprint author), W-NP53,808,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Wang, Julian/C-3188-2016 NR 15 TC 37 Z9 40 U1 2 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 1 PY 2001 VL 28 IS 21 BP 4107 EP 4110 DI 10.1029/2001GL013660 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 485TM UT WOS:000171780000025 ER PT J AU Gupta, AK Dhingra, H Melice, JL Anderson, DM AF Gupta, AK Dhingra, H Melice, JL Anderson, DM TI Earth's Eccentricity Cycles and Indian Summer Monsoon variability over the past 2 million years: Evidence from deep-sea Benthic Foraminifer SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TIME-SERIES ANALYSIS; UNEVENLY SPACED DATA; ARABIAN SEA; LATE QUATERNARY; SPECTRAL-ANALYSIS; OCEAN; PRODUCTIVITY; CLIMATE; PLEISTOCENE; INSOLATION AB Spectral analysis of a Uvigerina proboscidea time series from DSDP Site 214 using the Lomb-Scargle method for unevenly sampled data, exhibits two dominant power peaks at 412 and 94 kyrs over the last 2 million years, which correspond to the Earth's eccentricity cycles. The results indicate that the SW monsoon varied at about 100 kyr and 400 kyr periodicities within Earth's eccentricity domain (Mlankovitch range) over the past 2 million years. Wavelet transform analysis reveals the non-stationary nature of monsoon upwelling over this interval. The amplitude of the 400 kyr cycle in the U. proboscidea time series began to increase at similar to 900 kyrs as has also been observed in few recent studies. We do not see a strong relation between eccentricity highs and intense summer monsoons over the studied interval. C1 Indian Inst Technol, Dept Geol & Geophys, Kharagpur 721302, W Bengal, India. Univ Paris 06, Lab Oceanog Dynam & Climatol, IRD, F-75252 Paris 05, France. NOAA, Paleoclimatol Program, Boulder, CO 80303 USA. RP Gupta, AK (reprint author), Indian Inst Technol, Dept Geol & Geophys, Kharagpur 721302, W Bengal, India. RI anderson, david/E-6416-2011 NR 45 TC 16 Z9 17 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 1 PY 2001 VL 28 IS 21 BP 4131 EP 4134 DI 10.1029/2001GL013315 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 485TM UT WOS:000171780000031 ER PT J AU Romanyukha, AA Seltzer, SM Desrosiers, M Ignatiev, EA Ivanov, DV Bayankin, S Degteva, MO Eichmiller, FC Wieser, A Jacob, P AF Romanyukha, AA Seltzer, SM Desrosiers, M Ignatiev, EA Ivanov, DV Bayankin, S Degteva, MO Eichmiller, FC Wieser, A Jacob, P TI Correction factors in the EPR dose reconstruction for residents of the Middle and Lower Techa riverside SO HEALTH PHYSICS LA English DT Article DE dose assessment; Sr-90; radiation, ionizing; exposure, cumulative ID TOOTH-ENAMEL; NUCLEAR WORKERS; DOSIMETRY; POPULATION; BONE; SYSTEM AB During 1949-1956, the first Soviet nuclear weapons plant, Mayak, released about 7.6 x 10(7) m(-3) of liquid radioactive waste with a total activity of 10(17) Bq into the Techa River (Southern Urals, Russia). Sr-90 contributed 11.6% to the total waste radioactivity. As a result of these radioactive discharges, about 28,000 local residents were exposed to ionizing radiation, and some of them received relatively high doses. Internal exposure of the population residing at the Middle and Lower Techa riverside was mostly from Sr-90 deposited in bone and tooth tissues. In order to reconstruct radiation doses to this population group, a study of 35 teeth extracted from local residents was carried out using electron paramagnetic resonance measurements. A total of 73 samples from these 35 teeth (tooth enamel, 33; crown dentin, 20; and root dentin, 20) were prepared and measured with electron paramagnetic resonance. The study revealed high doses (up to 15 Gy) absorbed in tooth enamel of the individuals born during 1945-1949, which was attributed to very high local Sr-90 concentration in tooth enamel of this particular age group in the population. The analysis presented here takes into account (a) the time courses both of the release/intake of Sr-90 and of the tooth formation, and (b) expected variations in measured absorbed doses due to differing geometric sizes of tooth structures. This methodology enables a more consistent picture to be developed of the Sr-90 intake by the Middle and Lower Techa riverside population, based on electron paramagnetic resonance tooth dosimetry. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Russian Acad Sci, Inst Met Phys, Ekaterinburg 620219, Russia. Urals Res Ctr Radiat Med, Chelyabinsk 454076, Russia. NIST, Amer Dent Assoc Hlth Fdn, Gaithersburg, MD 20899 USA. GSF, Natl Res Ctr Environm & Hlth, Inst Radiat Protect, D-85764 Neuherberg, Germany. RP Romanyukha, AA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM romanyuk@nist.gov RI Ivanov, Denis/J-3235-2013 OI Ivanov, Denis/0000-0001-6757-5587 NR 25 TC 23 Z9 24 U1 1 U2 6 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD NOV PY 2001 VL 81 IS 5 BP 554 EP 566 DI 10.1097/00004032-200111000-00010 PG 13 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 484GZ UT WOS:000171683000010 PM 11669209 ER PT J AU Williams, DF Holloway, CL AF Williams, DF Holloway, CL TI Transmission-line parameter approximation for digital simulation SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE CM; digital simulation; frequency-dependent parameters; microstrip; transmission-line parameters AB This paper compares closed-form approximations for coplanar waveguide and microstrip transmission-line parameters to accurate measurements and full-wave calculations. We suggest improved approximations and demonstrate the limitations of our proposed and current approximations for the efficient simulation of digital interconnects. C1 Natl Inst Stand & Technol, RF Technol Div, Boulder, CO 80303 USA. RP Williams, DF (reprint author), Natl Inst Stand & Technol, RF Technol Div, 325 Broadway, Boulder, CO 80303 USA. NR 14 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD NOV PY 2001 VL 43 IS 4 BP 466 EP 470 DI 10.1109/15.974625 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 510GB UT WOS:000173199400006 ER PT J AU Scarlatti, A Holloway, CL AF Scarlatti, A Holloway, CL TI An equivalent transmission-line model containing dispersion for high-speed digital lines - With an FDTD implementation SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE equivalent transmission-line model; FDTD; frequency dependent parameters; high-speed digital lines; lossy lines; signal integrity ID CONDUCTOR LOSS; SIMULATION; APPROXIMATIONS; EXPRESSIONS; MICROSTRIP; STRIP AB The increase in processor speeds in the last few years has created a growing need for the accurate characterization of waveform propagation on lossy printed-circuit-board (PCB) transmission lines. Due to the dispersive nature of pulse propagation on lossy transmission lines, approximations of the classic transmission-line model can fail in this application (i.e., lossless or dc losses approximations). This paper will show how an equivalent-transmission-line model can be used to analyze dispersive transmission lines for high-speed digital applications. The equivalent-circuit elements of this transmission-line model incorporate the frequency dependence of the per unit length impedance and admittance caused by the finite conductivity of the conductors as well as the dielectric losses. We will show that these equivalent circuit elements can be readily implemented into finite-difference time-domain (FDTD) transmission-line codes, and we will present such a FDTD implementation. S-parameters and pulsed waveforms for a circular wire, coplanar waveguides (CPW) and microstrip lines are shown. Finally, we present approximate expressions for analytically obtaining the resistance and inductance per length of a microstrip line. C1 Univ Roma La Sapienza, Dept Elect Engn, I-00184 Rome, Italy. Natl Inst Stand & Technol, Radio Frequency Technol Div, US Dept Commerce, Boulder Labs, Boulder, CO 80303 USA. RP Scarlatti, A (reprint author), Univ Roma La Sapienza, Dept Elect Engn, Piazzale Aldo Moro 5, I-00184 Rome, Italy. NR 36 TC 23 Z9 24 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 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD NOV PY 2001 VL 43 IS 4 BP 504 EP 514 DI 10.1109/15.974629 PG 11 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 510GB UT WOS:000173199400010 ER PT J AU Gasiewski, A St Germain, K AF Gasiewski, A St Germain, K TI Special issue on the 2000 International Geoscience and Remote Sensing Symposium (Igarss'00): Taking the pulse of the planet - Foreword SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Editorial Material C1 NOAA, Environm Technol Lab, Boulder, CO 80305 USA. USN, Res Lab, Washington, DC 20375 USA. RP Gasiewski, A (reprint author), NOAA, Environm Technol Lab, Boulder, CO 80305 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD NOV PY 2001 VL 39 IS 11 BP 2323 EP 2324 DI 10.1109/TGRS.2001.964966 PG 2 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 494LV UT WOS:000172284900001 ER PT J AU Piepmeier, JR Gasiewski, AJ AF Piepmeier, JR Gasiewski, AJ TI Digital correlation microwave polarimetry: Analysis and demonstration SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT International Geoscience and Remote Sensing Symposium (IGARSS 00) CY JUL 24-28, 2000 CL HONOLULU, HAWAII SP IEEE Geosci & Remote Sensing Soc DE correlator; digital; polarimetry; radiometer; Stokes vector ID BRIGHTNESS TEMPERATURES; QUANTIZATION; RADIOMETERS AB The design, analysis, and demonstration of a digital-correlation microwave polarimeter for use in Earth remote sensing is presented. We begin with an analysis of a three-level digital correlator and develop the correlator transfer function and radiometric sensitivity. A fifth-order polynomial regression is derived for inverting the digital correlation coefficient into the analog statistic. In addition, the effects of quantizer threshold asymmetry and hysteresis are discussed. A two-look unpolarized calibration scheme is developed for identifying correlation offsets. The developed theory and calibration method are verified using a 10.7 GHz and a 37.0 GHz polarimeter. The polarimeters are based upon 1-GS/s three-level digital correlators and measure the first three Stokes parameters. Through experiment, the radiometric sensitivity is shown to approach the theoretical as derived earlier in the paper and the two-look unpolarized calibration method is successfully compared with results using a polarimetric scheme. Finally, sample data from an aircraft experiment demonstrates that the polarimeter is highly useful for ocean wind-vector measurement. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 21146 USA. NOAA, Environm Technol Lab, Boulder, CO 80305 USA. RP Piepmeier, JR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 21146 USA. NR 32 TC 16 Z9 20 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 NOV PY 2001 VL 39 IS 11 BP 2392 EP 2410 DI 10.1109/36.964976 PG 19 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 494LV UT WOS:000172284900009 ER PT J AU Bae, S Zurn, S Egelhoff, WF Chen, PJ Sheppard, L Torok, EJ Judy, JH AF Bae, S Zurn, S Egelhoff, WF Chen, PJ Sheppard, L Torok, EJ Judy, JH TI Fabrication and thermal-chemical stability of magnetoresistive random-access memory cells using alpha-Fe2O3 bottom spin valves SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article DE alpha-Fe2O3 giant magnetoresistance (GMR) spin; valve; magnetoresistive random-access memory (MRAM) fabrication; SPICE modeling; thermal and chemical stability ID DEPENDENCE; BILAYERS AB This paper discusses fabrication stability and device characteristics of Si/alpha -Fe2O3 (25 nm)/Co (3 nm)/Cu (2.3 nm)/Co (3.1 nm)/Ta2O5 (2.5 nm) giant magnetoresistance (GMR) spin-valve magnetoresistive random-access memory (MRAM) cells 6 mum wide and 18 mum long dimension. Fabricated single-bit and 3 x 3-bit MRAM cells had very good GMR performance for MRAM characteristics and excellent endurance in undergoing standard high-temperature semiconductor processes. The high thermal and chemical stability of alpha -Fe2O3 bottom GMR spin valves is mainly attributed to the good thermal stability associated with the high blocking temperature (about 390 degreesC) and the good corrosion resistance of the alpha -Fe2O3 antiferromagnetic material. In this paper, models for an individual alpha -Fe2O3 bottom GMR spin-valve MRAM cell using SPICE device model elements are introduced for the first time. The SPICE model is useful for predicting the MRAM device characteristics related to the speed and power dissipation in different MRAM bit arrays and under various operating conditions. C1 Univ Minnesota, Ctr Micromagnet & Informat Technol, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. Integrated MagnetoElect Co, Minneapolis, MN 55406 USA. Natl Inst Stand & Technol, Magnet Mat Grp, Gaithersburg, MD 20899 USA. RP Bae, S (reprint author), Univ Minnesota, Ctr Micromagnet & Informat Technol, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. NR 20 TC 4 Z9 4 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD NOV PY 2001 VL 37 IS 6 BP 3960 EP 3968 DI 10.1109/20.966133 PN 1 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 500YE UT WOS:000172655600014 ER PT J AU Cresswell, MW Bonevich, JE Allen, RA Guillaume, NMP Giannuzzi, LA Everist, SC Murabito, CE Shea, PJ Linholm, LW AF Cresswell, MW Bonevich, JE Allen, RA Guillaume, NMP Giannuzzi, LA Everist, SC Murabito, CE Shea, PJ Linholm, LW TI Electrical linewidth test structures patterned in (100) silicon-on-insulator for use as CD standards SO IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING LA English DT Article DE BESOI; cross-bridge resistor; electrical CD; HRTEM; linewidth; SEM; silicon micromachining; silicon-on-insulator; standards; traceability ID MONOCRYSTALLINE FILMS AB Electrical test structures known as cross-bridge resistors have been patterned in (100) epitaxial silicon material that was grown on Bonded and Etched-back Silicon-On-Insulator (BESOT) substrates. The critical dimensions (CDs) of a selection of their reference segments have been measured electrically, by scanning-electron microscopy (SEM), and by lattice-plane counting. The lattice-plane counting is performed on phase-contrast images of the cross sections of the reference segments that are produced by high-resolution transmission-electron microscopy (HRTEM). The reference-segment features were aligned with (110) directions in the BESOT surface material. They were defined by a silicon micromachining process that resulted in their sidewalls being nearly atomically planar and smooth and inclined at 54.737 degrees to the surface (100) plane of the substrate. SEM, HRTEM, and electrical CD (ECD) linewidth measurements have been made on features of various drawn dimensions on the same substrate to investigate the feasibility of a CD traceability path that combines the low cost, robustness, and repeatability of ECD metrology and the absolute measurement of the HRTEM lattice-plane counting technique. Other novel aspects of the (100) silicon-on-insulator (SOI) implementation that are reported here are the ECD test-structure architecture and the making of lattice-plane counts from cross-sectional HRTEM imaging of the reference features. This paper describes the design details and the fabrication of the cross-bridge resistor test structure. The long-term goal is to develop a technique for the determination of the absolute dimensions of the trapezoidal cross sections of the cross-bridge resistors' reference segments, as a prelude to making them available for dimensional reference applications. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. George Washington Univ, Washington, DC 20052 USA. Univ Cent Florida, Orlando, FL 32816 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cresswell, MW (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. NR 21 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0894-6507 J9 IEEE T SEMICONDUCT M JI IEEE Trans. Semicond. Manuf. PD NOV PY 2001 VL 14 IS 4 BP 356 EP 364 DI 10.1109/66.964322 PG 9 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 493PD UT WOS:000172231100007 ER PT J AU Herzler, J Manion, JA Tsang, W AF Herzler, J Manion, JA Tsang, W TI 1,2-pentadiene decomposition SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID HIGH-TEMPERATURE PYROLYSIS; C3H4 SURFACE; SHOCK-WAVES; ISOMERIZATION; 1,3-BUTADIENE; DISSOCIATION; ABINITIO; PROPYNE; VINYL; TUBE AB 1,2-Pentadiene has been decomposed in single pulse shock tube experiments. There appear to be a large number of parallel decomposition and isomerization channels. The following rate expressions for isomerization in the temperature range 1100-1250 K and pressures between 200 and 300 kPa have been obtained k (1,2-pentadiene --> -pentyne) = 1.0 x 10(13) exp(-32300 +/- 900 K/T) s(-1) k(1,2-pentadiene --> cis/trans-1,3-pentadiene = 2.2 x 10(14) exp(-33900 +/- 900 K/T) s(-1) k(1,2-pentadiene --> cyclopentene) = 1.8 x 10(11) exp(-26080 +/- 900 K/T)s(-1) Overall, we estimate the 2 sigma uncertainty in the absolute rate constants to be about 30%. From detailed balance the rate expression for 1,3 to 1,2-pentadiene isomerization has been found to be k(1,3-pentadiene --> 1,2-pentadiene) = 1.2 x 10(15) exp(-42070 +/- 900 K/T) s(-1) The significance of the 13 to 1,2 isomerization process as a bridge between the two-carbon and three-carbon species in high temperature hydrocarbon decomposition systems Is discussed. The decomposition processes involve bond breaking and retroene reactions. The rate expression for the latter has been found to be k(1,2-pentadiene --> propyne + ethylene) = 6.6 x 10(12) exp(-29240 +/- 900 K/T) s(-1) The rate constants for fission of the C-3-C-4 and C-4-C-5 bonds appear to be close to each other, Our results indicate that the resonance energy of the 1,3-butadiene-2-yl radical is smaller than that of allyl radical by an amount equal to the pi bond conjugation energy of butadiene. (C) 2001 John Wiley & Sons, Inc. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Manion, JA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 30 TC 5 Z9 5 U1 1 U2 6 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD NOV PY 2001 VL 33 IS 11 BP 755 EP 767 DI 10.1002/kin.1072 PG 13 WC Chemistry, Physical SC Chemistry GA 480VJ UT WOS:000171483200013 ER PT J AU Xu, HHK Quinn, JB AF Xu, HHK Quinn, JB TI Whisker-reinforced bioactive composites containing calcium phosphate cement fillers: Effects of filler ratio and surface treatments on mechanical properties SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE calcium phosphate cement; bioactive composite; hydroxyapatite; whiskers; reinforcement; strength; modulus ID DENTAL RESIN COMPOSITES; BONE-BONDING STRENGTH; CANAL SEALER-FILLER; HYDROXYAPATITE CEMENT; BIOLOGICAL PROPERTIES; GLASS POWDER; WOLLASTONITE; APATITE; RECONSTRUCTION; CONVERSION AB Calcium phosphate cement (CPC) sets to form microporous solid hydroxyapatite with excellent osteoconductivity, but its brittleness and low strength prohibit use in stress-bearing locations. The aim of this study was to incorporate prehardened CPC particles and ceramic whiskers in a resin matrix to improve the strength and fracture resistance, and to investigate the effects of key microstructural variables on composite mechanical properties. Two types of whiskers were used: silicon nitride, and silicon carbide. The whiskers were surface-treated by fusing with silica and by silanization. The CPC particle fillers were either silanized or not silanized. Seven mass ratios of whisker-silica/CPC were mixed: 0:1 (no whisker-silica), 1:5, 1:2, 1:1, 2:1, 5:1, and 1:0 (no CPC). Each powder was blended with a bisphenol-a-glycidyl methacrylate-based resin to harden in 2 x 2 x 25 mm molds by two-part chemical curing. The specimens were tested in three-point flexure to measure strength, work-of-fracture (toughness), and elastic modulus. Two-way analysis of variance was used to analyze the data, and scanning electron microscopy was used to examine specimen fracture surfaces. The whisker-silica/CPC ratio had significant effects on composite properties (p < 0.001). When this ratio was increased from 0:1 to 1:0, the strength was increased by about three times, work-of-fracture by five times, and modulus by two times. Whisker surface treatments and CPC filler silanization also had significant effects (p < 0.001) on composite properties. Scanning electron microscopy revealed rough fracture surfaces for the whisker composites with steps and whisker pullout. Resin remnants were observed on the surfaces of the pulled-out whiskers, indicating strong whisker-matrix bonding. In conclusion, incorporating highly osteoconductive CPC fillers and ceramic whiskers yielded composites with substantially improved mechanical properties compared with composites filled with CPC particles without whiskers. The composite properties were determined by whisker-to-CPC ratio and filler surface treatments. <(c)> 2001 John Wiley & Sons, Inc. C1 NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. RP Xu, HHK (reprint author), NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, 100 Bur Dr Stop 8546, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [R29 DE12476] NR 50 TC 26 Z9 32 U1 2 U2 12 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD NOV PY 2001 VL 57 IS 2 BP 165 EP 174 DI 10.1002/1097-4636(200111)57:2<165::AID-JBM1155>3.0.CO;2-W PG 10 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 466QP UT WOS:000170656500002 PM 11484178 ER PT J AU Kamilov, IK Stepanov, GV Abdulagatov, IM Rasulov, AR Milikhina, EI AF Kamilov, IK Stepanov, GV Abdulagatov, IM Rasulov, AR Milikhina, EI TI Liquid-liquid-vapor, liquid-liquid, and liquid-vapor phase transitions in aqueous n-hexane mixtures from isochoric heat capacity measurements SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID PLUS HYDROCARBON SYSTEMS; SUPERCRITICAL WATER; HIGH-PRESSURES; THERMODYNAMIC PROPERTIES; VIRIAL-COEFFICIENTS; NEUTRON-SCATTERING; NITROGEN TETROXIDE; HIGH-TEMPERATURES; BINARY-SYSTEMS; FLUID MIXTURES AB The constant volume and constant composition heat capacity C-VX data for aqueous n-hexane mixtures are reported for seven compositions, (0.6146, 0,7965, 0.9349, 0.9775, 0.9858, 0.9892, and 0.9940) mol fraction of n-hexane, along seven near-critical isochores between 259.34 and 312.50 kg(.)m(-3) in the temperature range from 463 to 522 K at pressures up to 6 MPa. All of these isochores display two features in the heat capacity as a function of temperature: the first peak appears when one of the liquid phases disappears, and the second peak appears when the vapor or liquid phase disappears. These features are interpreted in terms of the liquid-liquid-vapor, liquid-liquid, and liquid-vapor phase diagram, and their consistency is shown with earlier PTx measurements on the three-phase (L-L-G) boundary. Measurements of the isochoric heat capacity (C(V)VTx) of water + n-hexane mixtures were made in a spherical high-temperature, high-pressure nearly constant volume adiabatic calorimeter. The calorimeter was also used as a constant-volume piezometer to measure the PVTx properties. The uncertainties of the measurements are as follows: isochoric heat capacity, 1.0-1.5%; density, 0.1%; temperature, 10 mK, and pressure, 0.05%. The method of quasi-static thermograms was used to precisely measure the liquid-liquid-gas (L-L-G), liquid-liquid (L-L), and liquid-gas (L-G) phase transition temperatures at each fixed density, with an uncertainty of 0.02 K. New saturated densities and pressures are presented on the (LL-G) and (L-G) phase boundaries. The values of temperature, pressure, and density of the upper critical end point (UCEP) in the water + n-hexane mixture were determined from the measurements. Results for the UCEP (T-UCEP = 495.82 K; P-UCEP = 5.25 MPa; rho (UCEP) = 259.9 kg(.)m(-3)) are in good agreement with the values reported by other authors. For the first time the temperature-dependent behavior of C-VX near the UCEP is reported. C1 Russian Acad Sci, Daghestan Sci Ctr, Inst Phys, Makhachkala 367003, Dagestan, Russia. RP Abdulagatov, IM (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80305 USA. NR 90 TC 34 Z9 37 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD NOV-DEC PY 2001 VL 46 IS 6 BP 1556 EP 1567 DI 10.1021/je010136s PG 12 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 493VJ UT WOS:000172243900041 ER PT J AU Rabezkii, MG Bazaev, AR Abdulagatov, IM Magee, JW Bazaev, EA AF Rabezkii, MG Bazaev, AR Abdulagatov, IM Magee, JW Bazaev, EA TI PVTx measurements for water plus toluene mixtures in the near-critical and supercritical regions SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID PHASE-EQUILIBRIA; HYDROCARBON SYSTEMS; DILUTE MIXTURES; CRITICAL-POINT; PRESSURES; BEHAVIOR; STATE; TEMPERATURE; EQUATION; SOLUTE AB The PVTx relationships of dilute (1 - x) water + x toluene mixtures were measured in the near-critical and supercritical regions, with a constant-volume piezometer immersed in a precision thermostat. The ITS-90 temperature was measured with a 10 Omega platinum resistance thermometer (PRT-10) with an uncertainty of 10 mK. Pressure was measured by means of a dead-weight gauge with an uncertainty of 1.5-2.0 kPa. Uncertainties of the density measurements are estimated to be 0.05-0.15%, depending on the experimental pressure and temperature. The uncertainty in composition measurement is 0.001 mole fraction. Measurements were made on near-critical and supercritical isotherms between 623 and 673 K at pressures from 11 to 46 MPa and densities between 54 and 579 kg(.)m(-3) for three composition mole fractions of toluene (0.0008, 0.0022, and 0.0085). The measured PVTx data for (1 - x) water + x toluene mixtures were compared with values calculated from a recently developed crossover equation of state and published measurements. The PVTx measurements were used to derive values of the Krichevskii parameter, excess volumes, and apparent molar volumes. The method of isochoric break points was used to extract the phase transition temperatures and pressures for each measured isochore. The critical anomalies of the supercritical (1 - x) water + x toluene mixtures and the behavior of the Krichevskii function near the solvent's (water) critical point are discussed. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. Russian Acad Sci, Dagestan Sci Ctr, Inst Geothermal Res, Makhachkala 367030, Dagestan, Russia. RP Abdulagatov, IM (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80305 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 54 TC 18 Z9 19 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD NOV-DEC PY 2001 VL 46 IS 6 BP 1610 EP 1618 DI 10.1021/je010176w PG 9 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 493VJ UT WOS:000172243900051 ER PT J AU Forney, D Jacox, ME Lugez, CL Thompson, WE AF Forney, D Jacox, ME Lugez, CL Thompson, WE TI Matrix isolation study of the interaction of excited neon atoms with allene and propyne: Infrared spectra of H2CCCH2+ and H2CCCH- SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-ORBITAL CALCULATIONS; PHOTO-ION COINCIDENCE; VIBRATIONAL-SPECTRA; SOLID NEON; ELECTRONIC-STRUCTURE; PHOTOELECTRON-SPECTRUM; AB-INITIO; THRESHOLD PHOTOELECTRON; GAS-PHASE; C3H3+ AB When a Ne:allene or a Ne:propyne sample was codeposited at approximately 5 K with a sample of pure neon that had been excited in a microwave discharge to provide a 16.6-16.85 eV energy source, prominent new infrared absorptions which can be assigned to the H2CCCH2+ cation appeared. Also present in the allene experiments were two absorptions which can be assigned to H2CCCH-. In the propyne experiments, an absorption is tentatively attributed to the strongest infrared fundamental of CH3CCH+. The structures and vibrational fundamentals obtained from density functional and ab initio calculations for various isotopomers of H2CCCH2+, CH3CCH+, cyc-C3H3+, H2CCCH+, and H2CCCH- are given. The infrared absorption pattern of the cation common to the allene and propyne experiments matches that of the predominant gas-phase product, cyc-C3H3+, reasonably well, except for the presence of extra peaks in the CH-stretching region. However, comparison of the results of experiments on isotopically substituted samples with the calculated spectra excludes that assignment and supports the identification of the neon-matrix product as H2CCCH2+. It is suggested that collisions with the excess of neon atoms in the sampling region rapidly remove excess energy from the initially formed allene and propyne cations, inhibiting the loss of an H atom from those two species. (C) 2001 American Institute of Physics. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Forney, D (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 61 TC 14 Z9 14 U1 1 U2 20 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV PY 2001 VL 115 IS 18 BP 8418 EP 8430 DI 10.1063/1.1402998 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 486AT UT WOS:000171796800021 ER PT J AU Hinz, HJ Schwarz, FP AF Hinz, HJ Schwarz, FP TI Measurement and analysis of results obtained on biological substances with d.s.c. SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE differential scanning calorimetry; lipids; phase transition; proteins; transition enthalpy; transition temperature; unfolding transitions ID DIFFERENTIAL SCANNING CALORIMETRY; HEAT-CAPACITY DATA; DODECAMERIC GLUTAMINE-SYNTHETASE; ACANTHAMOEBA MYOSIN-II; THERMODYNAMIC DATA; ESCHERICHIA-COLI; THERMAL-DENATURATION; UNFOLDING TRANSITION; PROTEIN STABILITY; CALIBRATION AB The differential scanning calorimeter (d.s.c.) has been widely used to determine the thermodynamics of phase transitions and conformational changes in biological systems including proteins, nucleic acid sequences, and lipid assemblies. The d.s.c monitors the temperature difference between two vessels, one containing the biological solution and the other containing a reference solution, as a function of temperature at a given scan rate. Recommendations for d.s.c. measurement procedures, calibration procedures, and procedures for testing the performance of the d.s.c. are described. Analysis of the measurements should include a correction for the time response of the instrument and conversion of the power versus time curve to a heat capacity versus temperature plot. Thermodynamic transition models should only be applied to the analysis of the heat capacity curves if the model-derived transition temperatures and enthalpies are independent of the d.s.c. scan rate. Otherwise, kinetic models should be applied to the analysis of the data. Application of thermodynamic transition models involving two states, two states and dissociation, and three states to the heat capacity versus temperature data are described. To check the operating performance with standard d.s.c.s, samples of (1 to 10) mg (.) cm(3) solutions of hen egg white lysozyme in 0. 1 mol (.) dm(-3) HCl-glycine buffer at pH = (2.4 +/- 0.1) were sent to six different d.s.c. laboratories worldwide. The values obtained from proper measurements and application of a two-state transition model yielded an average unfolding transition temperature for lysozyme of 331.2 K with values ranging between T = 329.4 K and 331.9 K, and an average transition enthalpy of 405 kJ (.) mol(-1) with values ranging from 377 kJ (.) mol(-1) to 439 kJ (.) mol(-1). It is recommended that the reporting of d.s.c. results be specific with regard to the composition of the solution, the operating conditions and calibrations of the d.s.c. determination of base lines that may be model dependent, and the model used in the analysis of the data. (C) 2001 Academic Press. C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Univ Munster, Inst Chem Phys, D-48149 Munster, Germany. RP Schwarz, FP (reprint author), NIST, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. NR 55 TC 14 Z9 14 U1 1 U2 2 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD NOV PY 2001 VL 33 IS 11 BP 1511 EP 1525 DI 10.1006/jcht.2001.0861 PG 15 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 532ZL UT WOS:000174504900006 ER PT J AU DeMartini, EE Williams, HA AF DeMartini, EE Williams, HA TI Fecundity and egg size of Scyllarides squammosus (Decapoda : Scyllaridae) at Maro Reef, Northwestern Hawaiian Islands SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article ID PANULIRUS-MARGINATUS; SPINY LOBSTER AB The body size-specific fecundity of Scyllarides squammosus is described based on the numbers of eggs carried externally on the pleopods of "berried" (ovigerous) females collected during June 1999, at Maro Reef, located mid-chain in the Northwestern Hawaiian Islands (NWHI). Fecundity was positively and nonlinearly related to "tail" (abdomen) width (TW); fecundity ranged from 53,807 to 227,489 eggs in 43 females spanning 52-77-mm. TW. The smallest berried female encountered at Maro Reef in 1999 was larger than the smallest berried female observed during most previous years' (1986-97) lobster research cruises. Fecundity of the median-sized (60-mm TW) female caught at Maro Reef in 1999 by the NWHI commercial lobster trap fishery was an estimated 89,660 +/- 3,980 (SE) eggs. Brooded eggs averaged 0.67 +/- 0.006-mm diameter (range: 0.61-0.77 mm), equivalent to 0.17 and 0.13-0.24 mg, respectively. Egg size was unrelated to female body size. Fecundity and egg size estimates and their body size relationships are briefly compared with other scyllarid lobsters. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. RP DeMartini, EE (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. NR 13 TC 14 Z9 15 U1 0 U2 3 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 USA SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD NOV PY 2001 VL 21 IS 4 BP 891 EP 896 DI 10.1651/0278-0372(2001)021[0891:FAESOS]2.0.CO;2 PG 6 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 491NJ UT WOS:000172114500003 ER PT J AU Swiney, KM Shirley, TC AF Swiney, KM Shirley, TC TI Gonad development of southeastern Alaskan dungeness crab, Cancer magister, under laboratory conditions SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article ID INVERTEBRATE REPRODUCTION; BRACHYURA; BIOLOGY; GROWTH AB The large percentage of nonovigerous adult female crabs in situ gave rise to the question of whether egg extrusion occurs annually in Dungeness crabs in Alaskan waters as is reported for lower-latitude populations. Accordingly, We Studied seasonal variation in gonadal development for 280 male, nonovigerous female, and ovigerous female crabs, reared in flow-through tanks from October 1997 through October 1998. Gonadosomatic indexes (GSI) were determined monthly from March through October 1998 for nonovigerous females, ovigerous females, and males. Oocyte area was also measured for females over the same period. Approximately 10 crabs from each treatment group were sampled monthly. Male GSI increased significantly over time. Nonovigerous females had significantly higher GSI and oocyte areas than ovigerous females. The GSI in October decreased significantly from the GSI in September among nonovigerous females in the laboratory and field, suggesting resorption of gonads. Most mature females do not extrude eggs annually in southeastern Alaska; however, under laboratory conditions, some females can extrude eggs in consecutive years. C1 Univ Alaska Fairbanks, Sch Fisheries & Ocean Sci, Juneau Ctr, Juneau, AK 99801 USA. RP Swiney, KM (reprint author), Kodiak Fisheries Res Ctr, Natl Marine Fisheries Serv, NOAA, 301 Res Court, Kodiak, AK 99615 USA. NR 27 TC 17 Z9 18 U1 1 U2 3 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 USA SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD NOV PY 2001 VL 21 IS 4 BP 897 EP 904 DI 10.1651/0278-0372(2001)021[0897:GDOSAD]2.0.CO;2 PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 491NJ UT WOS:000172114500004 ER PT J AU Gallagher, T AF Gallagher, T TI Protein packing interactions and polymorphy of chorismate lyase from E-Coli SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 8th International Conference on Crystallization of Biological Macromolecules CY MAY 14-19, 2000 CL SANDESTIN, FLORIDA DE crystal morphology; crystal structure; diffraction; proteins ID ESCHERICHIA-COLI; SUBTILISIN S88; CRYSTAL-GROWTH; 4-HYDROXYBENZOATE; CRYSTALLIZATION; DIFFRACTION; MECHANISM AB The enzyme chorismate lyase from E. coli crystallizes into three well characterized polymorphs in identical conditions. The Wild-type enzyme tends to aggregate, even in the presence of a reducing agent, and yields monoclinic crystals that grow in intricate clusters. Protein aggregation was largely eliminated by mutating the protein's two cysteines to serines. The double mutant retains full enzymatic activity and grows singly in two new forms: triclinic and orthorhombic. The triclinic crystals diffract to 0.9 Angstrom resolution. A single-cysteine mutant that crystallizes in the orthorhombic form was used to determine the structure, enabling examination of the packing interactions at 2.0 Angstrom resolution or better in all three forms. A novel system for labeling contacts is proposed, and relations between packing patterns and crystal properties are discussed. Diffraction resolution is found to correlate with coordination number and with the root-mean-square deviation from mean extent of the contacts. Implications for contact energies are considered. (C) 2001 Elsevier Science B.V. All rights reserved. C1 NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Gallagher, T (reprint author), NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 15 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD NOV PY 2001 VL 232 IS 1-4 BP 215 EP 220 DI 10.1016/S0022-0248(01)01090-9 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 473KL UT WOS:000171042700026 ER PT J AU Pulwarty, RS Melis, TS AF Pulwarty, RS Melis, TS TI Climate extremes and adaptive management on the Colorado River: Lessons from the 1997-1998 ENSO event SO JOURNAL OF ENVIRONMENTAL MANAGEMENT LA English DT Article DE climatic extremes; adaptive management; Colorado River; El Nino-Southern Oscillation; water resources; decision calendar; focusing events AB The Colorado River system exhibits the characteristics of a heavily over-allocated or 'closing water system'. In such systems, development of mechanisms to allow resource users to acknowledge interdependence and to engage in negotiations and agreements becomes necessary. Recently, after a decade of deliberations and environmental assessments, the Glen Canyon Dam Adaptive Management Program (GCDAMP) was established to monitor and analyze the effects of dam operations on the Grand Canyon ecosystem and recommend adjustments intended to preserve and enhance downstream physical, cultural and environmental values. The Glen Canyon Dam effectively separates the Colorado into its lower and upper basins. Dam operations and adaptive management decisions are strongly influenced by variations in regional climate. This paper focuses on the management of extreme climatic events within the Glen and Grand Canyon Region of the Colorado River. It illustrates how past events (both societal and physical) condition management flexibility and receptivity to new information. The types of climatic information and their appropriate entry points in the annual cycle of information gathering and decision-making (the 'hydro-climatic decision calendar) for dam operations and the adaptive management program are identified. The study then describes how the recently implemented program, lessons from past events, and new climate information on the Colorado River Basin, facilitated responses during the major El Nino-Southern Oscillation (ENSO) event of 1997-1998. Recommendations are made for engaging researchers and practitioners in the effective use of climatic information in similar settings where the decision stakes are complex and the system uncertainty is large. (C) 2001 Academic Press. C1 Univ Colorado, NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80309 USA. Dept Interior, Grand Canyon Monitoring & Res Ctr, Flagstaff, AZ 86001 USA. RP Pulwarty, RS (reprint author), NOAA, Off Global Programs, 1100 Wayne Ave,Suite 1225, Silver Spring, MD 20910 USA. EM pulwarty@ogp.noaa.gov NR 35 TC 40 Z9 41 U1 0 U2 9 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 NOV PY 2001 VL 63 IS 3 BP 307 EP 324 DI 10.1006/jema.2001.0494 PG 18 WC Environmental Sciences SC Environmental Sciences & Ecology GA 497EL UT WOS:000172442400007 PM 11775502 ER PT J AU O'Kelly, CJ Peglar, MT Black, MND Sawyer, TK Nerad, TA AF O'Kelly, CJ Peglar, MT Black, MND Sawyer, TK Nerad, TA TI Korotnevella hemistylolepis n. sp and Korotnevella monacantholepsis n. sp (Paramoebidae), two new scale-covered mesohaline amoebae SO JOURNAL OF EUKARYOTIC MICROBIOLOGY LA English DT Article DE amoeba morphology; Dactylamoeba; gymnamoebae; Mayorella; Neoparamoeba; Paramoeba; protistan taxonomy; scale structure; Vexilliferidae ID GENUS PYRAMIMONAS PRASINOPHYCEAE; GILL DISEASE; SEA; AMEBA AB Two new species of Korotnevella Goodkov, 1988, Korotnevella hemistylolepis n. sp. and Korotnevella monacantholepis n. sp., are described from mesohaline ecosystems. The amoebae are characterized on the basis of light and electron microscopy with special emphasis on the structure of the basket scales, which have species-specific architecture. The two new species are the second and third ones recovered from environments other than freshwater. In terms of scale morphology they most closely resemble a freshwater species, Korotnevella bulla (Schaeffer, 1926) Goodkov, 1988. Two genus names, Dactylamoeba Korotnev, 1880 and Korotnevella Goodkov, 1988, are in current use. The latter name is preferred, pending rediscovery and characterization of Dactylamoeba elongata Korotnev, 1880, the type species of the genus. Korotnevella species can be divided into three groups on the basis of scale morphology, suggesting that the genus may not be monophyletic. A key to species is provided. C1 Bigelow Lab Ocean Sci, Boothbay Harbor, ME 04575 USA. Amer Type Culture Collect, Protistol Collect, Manassas, VA 20110 USA. Natl Ocean Serv, NOAA, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. Rescon Associates Inc, Royal Oak, MD 21662 USA. RP O'Kelly, CJ (reprint author), Bigelow Lab Ocean Sci, POB 475, Boothbay Harbor, ME 04575 USA. RI Black, Megan/G-6410-2016 NR 36 TC 10 Z9 10 U1 0 U2 8 PU SOC PROTOZOOLOGISTS PI LAWRENCE PA 810 E 10TH ST, LAWRENCE, KS 66044 USA SN 1066-5234 J9 J EUKARYOT MICROBIOL JI J. Eukaryot. Microbiol. PD NOV-DEC PY 2001 VL 48 IS 6 BP 655 EP 662 DI 10.1111/j.1550-7408.2001.tb00205.x PG 8 WC Microbiology SC Microbiology GA 516VB UT WOS:000173576500007 ER PT J AU Wilson, GR Burke, WJ Maynard, NC Huang, CY Singer, HJ AF Wilson, GR Burke, WJ Maynard, NC Huang, CY Singer, HJ TI Global electrodynamics observed during the initial and main phases of the July 1991 magnetic storm SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ZONAL ELECTRIC-FIELDS; HIGH-LATITUDE; SUDDEN COMMENCEMENTS; INNER MAGNETOSPHERE; RING CURRENT; JUNE 4-6; PLASMA; TIME; CRRES; CONVECTION AB Data acquired by seven fortuitously positioned satellites in the interplanetary medium, the magnetosphere, and the topside ionosphere, as well as from numerous ground magnetometers have allowed us to follow the evolution of global currents and electric fields during the geomagnetic storm on July 8 - 9, 1991. An interplanetary disturbance collided with the magnetosphere at similar to 1636 UT on July 8th, compressing the magnetopause inside of geostationary orbit for about 3 hours, as observed by magnetometers on two GOES satellites. The resulting storm developed in four segments with a 7 hour lull separating the initial and main phases. The initial phase was characterized by (1) an extensive, DP 2 current system that produced an AE perturbation of similar to 3500 nT, with reporting stations on the dayside, (2) a twenty-fold increase in auroral electron fluxes, and (3) the immediate appearance of electric fields in the inner magnetosphere. The main phase intensification and earthward movement of the ring current are associated with southward turnings of the interplanetary magnetic field (IMF) and a polar cap potential increase above 200 kV. A significant fraction of the ring current growth was observed prior to the first of several substorms that occurred during the main and recovery phases. The beginning of recovery was characterized by a diminution of the southward IMF component, the cross polar cap potential and magnetospheric electric fields. It was also marked by a substorm onset. Considering the timing of Dst modulations relative to substorm occurrence, we conclude that during this magnetic storm, the electric fields responsible for ring current transport/energization were mostly associated with the DP 2 current system. Finally, in the evening-sector penetration electric fields of the initial and main phases led to the formation of upward moving equatorial plasma bubbles that were detected by two DMSP satellites in the topside ionosphere. C1 Mission Res Corp, Nashua, NH 03062 USA. USAF, Res Lab, Hanscom AFB, MA 01731 USA. Boston Coll, Inst Sci Res, Chestnut Hill, MA 02467 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Wilson, GR (reprint author), Mission Res Corp, 589 W Hollis St,Suite 201, Nashua, NH 03062 USA. NR 56 TC 30 Z9 34 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 2001 VL 106 IS A11 BP 24517 EP 24539 DI 10.1029/2000JA000348 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 490JT UT WOS:000172049300005 ER PT J AU Millward, GH Muller-Wodarg, ICF Aylward, AD Fuller-Rowell, TJ Richmond, AD Moffett, RJ AF Millward, GH Muller-Wodarg, ICF Aylward, AD Fuller-Rowell, TJ Richmond, AD Moffett, RJ TI An investigation into the influence of tidal forcing on F region equatorial vertical ion drift using a global ionosphere-thermosphere model with coupled electrodynamics SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GENERAL-CIRCULATION MODEL; MIGRATING SOLAR TIDES; ELECTRIC-FIELDS; SEMIDIURNAL TIDE; DYNAMO; WINDS; SIMULATION; ENHANCEMENT; IONIZATION; SATELLITE AB A recent development of the coupled thermosphere-ionosphere-plasmasphere model (CTIP) has been the inclusion of the electrodynamic coupling between the equatorial ionosphere and thermosphere. The vertical ion drifts which result are shown to be largely in agreement with empirical data, on the basis of measurements made at the Jicamarca radar and other equatorial sites [Scherliess and Fejer, 1999]. Of particular importance, the CTIP model clearly reproduces the "prereversal enhancement" in vertical ion drift, a key feature of the observational data. Inacurracies in the modeled daytime upward ion motion have been investigated with regard to changing the magnitude and phase of components of the lower thermospheric tidal forcing. The results show that daytime vertical ion motion is highly dependent upon both the magnitude and phase of the semidiurnal tidal component. In addition, the CTIP model shows the prereversal enhancement. to be unaffected by changes in tidal forcing, but only for conditions of high solar activity. During periods of low solar activity the form of the prereversal enhancement is clearly dependant upon the magnitude and phase of the semidiurnal tide. C1 UCL, Dept Phys & Astron, Atmospher Phys Lab, London W1P 7PP, England. Univ Colorado, NOAA, CIRES, Space Environm Ctr, Boulder, CO 80303 USA. Univ Sheffield, Dept Appl Math, Upper Atmosphere Modelling Grp, Sheffield S3 7RH, S Yorkshire, England. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. RP UCL, Dept Phys & Astron, Atmospher Phys Lab, 67-73 Riding House St, London W1P 7PP, England. EM george@theory.phys.ucl.ac.uk; i.mueller-wodarg@ucl.ac.uk; alan@apg.ph.ucl.ac.uk; tim.fuller-rowell@noaa.gov; richmond@hao.ucar.edu; r.moffett@sheffield.ac.uk RI Mueller-Wodarg, Ingo/M-9945-2014; OI Mueller-Wodarg, Ingo/0000-0001-6308-7826; Richmond, Arthur/0000-0002-6708-1023 NR 45 TC 89 Z9 89 U1 0 U2 5 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 NOV 1 PY 2001 VL 106 IS A11 BP 24733 EP 24744 DI 10.1029/2000JA000342 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 490JT UT WOS:000172049300019 ER PT J AU Wu, ST Zheng, HN Wang, S Thompson, BJ Plunkett, SP Zhao, XP Dryer, M AF Wu, ST Zheng, HN Wang, S Thompson, BJ Plunkett, SP Zhao, XP Dryer, M TI Three-dimensional numerical simulation of MHD waves observed by the Extreme Ultraviolet Imaging Telescope SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTION; EULERIAN FICE SCHEME; SOHO/EIT OBSERVATIONS; TRANSIENT; FLOWS AB We investigate the global large amplitude waves propagating across the solar disk as observed by the SOHO/Extreme Ultraviolet Imaging Telescope (EIT). These waves appear to be similar to those observed in H-alpha in the chromosphere and which are known as "Moreton waves," associated with large solar flares [Moreton, 1960, 1964]. Uchida [1968] interpreted these Moreton waves as the propagation of a hydromagnetic disturbance in the corona with its wavefront intersecting the chromosphere to produce the Moreton wave as observed in movie sequences of H-alpha images. To search for an understanding of the physical characteristics of these newly observed EIT waves, we constructed a three-dimensional, time-dependent, numerical magnetohydrodynamic (MHD) model. Measured global magnetic fields, obtained from the Wilcox Solar Observatory (WSO) at Stanford University, are used as the initial magnetic field to investigate hydromagnetic wave propagation in a three-dimensional spherical geometry. Using magnetohydrodynamic wave theory together with simulation, we are able to identify these observed EIT waves as fast mode MHD waves dominated by the acoustic mode, called magnetosonic waves. The results to be presented include the following: (1) comparison of observed and simulated morphology projected on the disk and the distance-time curves on the solar disk; (2) three-dimensional evolution of the disturbed magnetic field lines at various viewing angles; (3) evolution of the plasma density profile at a specific location as a function of latitude; and (4) computed Friedrich's diagrams to identify the MHD wave characteristics. C1 Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. Univ Alabama, Dept Mech Engn, Huntsville, AL 35899 USA. Univ Sci & Technol China, Dept Earth & Space Sci, Hefei 230026, Anhui, Peoples R China. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Washington, DC USA. Stanford Univ, Hansen Expt Phys Lab, Stanford, CA 94305 USA. NOAA, SEC, Boulder, CO 80305 USA. Explorat Phys Int Inc, Milford, NH USA. RP Wu, ST (reprint author), Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. RI Zheng, Huinan/A-1619-2010; Thompson, Barbara/C-9429-2012 NR 29 TC 133 Z9 137 U1 2 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 NOV 1 PY 2001 VL 106 IS A11 BP 25089 EP 25102 DI 10.1029/2000JA000447 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 490JT UT WOS:000172049300048 ER PT J AU Li, Y Luhmann, JG Mulligan, T Hoeksema, JT Arge, CN Plunkett, SP St Cyr, OC AF Li, Y Luhmann, JG Mulligan, T Hoeksema, JT Arge, CN Plunkett, SP St Cyr, OC TI Earthward directed CMEs seen in large-scale coronal magnetic field changes, SOHO LASCO coronagraph and solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WHOLE-SUN-MONTH; HELIOSPHERIC CURRENT SHEET; MASS EJECTIONS; CLOUDS; RECONNECTION; DISRUPTION; EVOLUTION; STREAMER; CYCLE AB One picture of coronal mass ejection (CME) initiation relates these events to the expansion into space of previously closed coronal magnetic fields, often part of the helmet streamer belt. The work described here makes use of the potential field source surface model based on updated synoptic photospheric field maps to study the large-scale coronal field changes. We isolate those field lines that change from closed to open configurations (newly opening field lines) by comparing potential field source surface models from adjacent magnetograph observations, wherein the same starting foot points on the photosphere are used. If there are some newly opening field lines between the times of two maps, we assume there was a possibility for CME occurrence(s) between these times. In particular, if there are newly opening field lines near the solar disk center, an earthward directed CME may have been generated. Monitoring the coronal magnetic field behavior can in principle reinforce (or not) days in advance predictions of magnetic storms based on Solar and Heliospheric Observatory (SOHO) Large-Angle Spectrometric Coronagraph (LASCO) halo CMEs. Moreover, the coronal field over the visible hemisphere contains information about the possible geoeffectiveness of a particular CME because it shows the approximate orientation and location of the active arcades. By comparing halo CMEs with the newly opening field lines, the solar wind measurements from Wind and ACE spacecraft and the Dst index, we show that, like soft X-ray sigmoids, disappearing filaments, and Extreme ultraviolet Imaging Telescope (EIT) waves on the disk of the Sun, magnetograph observation-based coronal field models may provide additional information on the likelihood of CME effects at the Earth. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. Stanford Univ, Ctr Space Sci & Astrophys, Stanford, CA 94305 USA. NOAA, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. Space Environm Ctr, Boulder, CO USA. Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Computat Phys Inc, Greenbelt, MD USA. RP Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM yanli@ssl.berkeley.edu; jgluhman@ssl.berkeley.edu; tamitha@igpp.ucla.edu; todd@quake.stanford.edu; nick@argel.nosa.gov; kett@ajcannon.nascom.nasa.gov; stcyr@cua.edu NR 40 TC 17 Z9 17 U1 0 U2 0 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 NOV 1 PY 2001 VL 106 IS A11 BP 25103 EP 25120 DI 10.1029/2001JA900041 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 490JT UT WOS:000172049300049 ER PT J AU Neupert, WM Thompson, BJ Gurman, JB Plunkett, SP AF Neupert, WM Thompson, BJ Gurman, JB Plunkett, SP TI Eruption and acceleration of flare-associated coronal mass ejection loops in the low corona SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOHO EIT OBSERVATIONS; X-RAY; SOLAR ERUPTIONS; SUN; TRANSIENT; LASCO; WAVES AB Observations made by the EUV imaging telescope (EIT) and the Large-Angle Spectrometric Coronagraph (LASCO) on board the Solar Heliospheric Observatory (SOHO) have been used to characterize the eruption and acceleration of flare-associated coronal mass ejections (CMEs) in the low corona. For three well-observed limb events we tracked CME loops back to preexisting but faint EUV-emitting loops at heights of 100-250 Min that initially brightened slowly and possibly increased slowly in height, apparently in response to filament activity and eruption in the associated active regions. Subsequent CME acceleration coincided with a rapid rise of the soft X-ray flux, occurred between 100 and 350 Mm above the surface, and may have been as high as 0.5 km s(-1) s(-1), consistent with an impulsive acceleration of the CME to the speeds observed in subsequent white-light observations. The existence of a delay of up to 30 min observed between initial filament eruption in H alpha and subsequent high acceleration of the CME in one event implies that there may have been two separate phases of magnetic reconnection, with the initial filament activity acting as a trigger for subsequent CME and energetic particle acceleration in the impulsive stage of the flare. The presence or absence of this impulsive phase may provide a basis for the two types of CMEs that have been discussed in the literature. C1 NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Raytheon STX Corp, Lanham, MD USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. USN, Res Lab, Solar Phys Branch, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Neupert, WM (reprint author), NOAA, Space Environm Ctr, Code R-E-SE,325 Broadway, Boulder, CO 80303 USA. RI Thompson, Barbara/C-9429-2012 NR 37 TC 50 Z9 52 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 2001 VL 106 IS A11 BP 25215 EP 25225 DI 10.1029/2000JA004012 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 490JT UT WOS:000172049300060 ER PT J AU Onsager, TG Scudder, JD Lockwood, M Russell, CT AF Onsager, TG Scudder, JD Lockwood, M Russell, CT TI Reconnection at the high-latitude magnetopause during northward interplanetary magnetic field conditions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID BOUNDARY-LAYER; DAYSIDE MAGNETOPAUSE; LOW-ALTITUDE; MAGNETOSHEATH PLASMA; ION PRECIPITATION; CUSP OBSERVATIONS; POLAR CUSP; CONVECTION; IMF; MAGNETOSPHERE AB The Polar spacecraft had a prolonged encounter with the high-latitude dayside magnetopause on May 29, 1996. This encounter with the magnetopause occurred when the interplanetary magnetic field was directed northward. From the three-dimensional electron and ion distribution functions measured by the Hydra instrument, it has been possible to identify nearly all of the distinct boundary layer regions associated with high-latitude reconnection. The regions that have been identified are (1) the cusp; (2) the magnetopause current layer; (3) magnetosheath field lines that have interconnected in only the Northern Hemisphere; (4) magnetosheath field lines that have interconnected in only the Southern Hemisphere; (5) magnetosheath field lines that have interconnected in both the Northern and Southern Hemispheres; (6) magnetosheath that is disconnected from the terrestrial magnetic field; and (7) high-latitude plasma sheet field lines that are participating in magnetosheath reconnection. Reconnection over this time period was occurring at high latitudes over a broad local-time extent, interconnecting the magnetosheath and lobe and/or plasma sheet field lines in both the Northern and Southern Hemispheres. Newly closed boundary layer field lines were observed as reconnection occur-red first at high latitudes in one hemisphere and then later in the other. These observations establish the location of magnetopause reconnection during these northward interplanetary magnetic field conditions as being at high latitudes, poleward of the cusp, and further reinforce the general interpretation of electron and ion phase space density signatures as indicators of magnetic reconnection and boundary layer formation. C1 NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. RP Onsager, TG (reprint author), NOAA, Space Environm Ctr, 325 Broadway, Boulder, CO 80303 USA. RI Lockwood, Mike/G-1030-2011; Scudder, Jack/D-8417-2013 OI Lockwood, Mike/0000-0002-7397-2172; Scudder, Jack/0000-0001-7975-5630 NR 38 TC 122 Z9 124 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 2001 VL 106 IS A11 BP 25467 EP 25488 DI 10.1029/2000JA000444 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 490JT UT WOS:000172049300079 ER PT J AU Su, YH Ergun, RE Peterson, WK Onsager, TG Pfaff, R Carlson, CW Strangeway, RJ AF Su, YH Ergun, RE Peterson, WK Onsager, TG Pfaff, R Carlson, CW Strangeway, RJ TI Fast Auroral Snapshot observations of cusp electron and ion structures SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID LOW-ALTITUDE OBSERVATIONS; FLUX-TRANSFER EVENTS; MAGNETOPAUSE RECONNECTION; DAYSIDE MAGNETOPAUSE; FIELD; PRECIPITATION; SIGNATURES; ACCELERATION; BOUNDARY; REGIONS AB The high time resolution observations by the Fast Auroral Snapshot satellite resolve burst-like electrons and nonmonotonic ion dispersion in the cusp region. Electric field data from a dawn-dusk cusp crossing show that the DC electric field has small-scale variations superimposed on a large-scale pattern. The large-scale DC electric field variations are well correlated with the large-scale perturbation magnetic field, indicating a field-aligned current system that reflects a relatively homogenous conductivity. Ion structures best correlate with the perturbed magnetic field and the large-scale electric field. The burst-like precipitating electrons are correlated with the small-scale electric field variations, which are most easily explained as propagating Alfven waves. We also found that the observed ion structures result from the spacecraft crossing the flow streamlines, each of which has its own individual history of dayside reconnection. The magnetosheath ion structures therefore contain information of both the spatial and temporal variations of dayside reconnection. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. Lockheed Martin Adv Technol Ctr, Palo Alto, CA 94304 USA. NOAA, Space Environm Lab, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. RP Su, YH (reprint author), Univ Colorado, Atmospher & Space Phys Lab, 1234 Innovat Dr, Boulder, CO 80303 USA. RI Pfaff, Robert/F-5703-2012; Peterson, WK/A-8706-2009 OI Pfaff, Robert/0000-0002-4881-9715; Peterson, WK/0000-0002-1513-6096 NR 28 TC 21 Z9 21 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 2001 VL 106 IS A11 BP 25595 EP 25600 DI 10.1029/2001JA000093 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 490JT UT WOS:000172049300087 ER PT J AU Pitcher, KW Burkanov, VN Calkins, DG Le Boeuf, BJ Mamaev, EG Merrick, RL Pendleton, GW AF Pitcher, KW Burkanov, VN Calkins, DG Le Boeuf, BJ Mamaev, EG Merrick, RL Pendleton, GW TI Spatial and temporal variation in the timing of births of Steller sea lions SO JOURNAL OF MAMMALOGY LA English DT Article DE birth timing; Eumetopias jubatus; nutritional status; reproduction; Steller sea lion ID NORTHERN FUR-SEAL; EUMETOPIAS-JUBATUS; REPRODUCTIVE SYNCHRONY; DECLINING POPULATION; CALLORHINUS-URSINUS; PARTURITION; FEMALE; ALASKA; IMPLANTATION; BEHAVIOR AB Throughout the range of the Steller sea lion (Eumetopias jubatus), nearly all births of fullterm pups observed from 1968 to 1998 occurred between 15 May and 15 July. We found significant differences in timing of births between rookeries with the earliest mean date of birth (4 June) at Forrester Island, Alaska, and the latest (21 June) at Ano Nuevo Island, California. Mean date of birth becomes progressively later both north and south of Forrester Island. Births at individual rookeries were synchronous, with 90% of pups born within a 25-day period. We hypothesize that timing of births at rookeries is determined through selection for time periods when weather conditions are generally favorable for pup survival and when adequate prey items are predictably available near rookeries for lactating females. Temporal differences also were found in mean date of birth at 4 rookeries, with a maximum difference between earliest and latest mean date of birth of 10.2 days at Ano Nuevo Island. The most likely explanation for temporal variability at individual rookeries is variable nutritional status of reproductive females. C1 Alaska Dept Fish & Game, Div Wildlife Conservat, Anchorage, AK 99518 USA. Alaska Sealife Ctr, Seward, AK 99664 USA. Univ Calif Santa Cruz, Dept Biol, Santa Cruz, CA 95064 USA. Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA. Biodivers Conservat Ctr, Moscow 117312, Russia. Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. Alaska Dept Fish & Game, Div Wildlife Conservat, Douglas, AK 99824 USA. RP Pitcher, KW (reprint author), Alaska Dept Fish & Game, Div Wildlife Conservat, 333 Raspberry Rd, Anchorage, AK 99518 USA. NR 38 TC 44 Z9 45 U1 1 U2 10 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 USA SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD NOV PY 2001 VL 82 IS 4 BP 1047 EP 1053 DI 10.1644/1545-1542(2001)082<1047:SATVIT>2.0.CO;2 PG 7 WC Zoology SC Zoology GA 496GH UT WOS:000172387500016 ER PT J AU Schmitz, TL Davies, MA Kennedy, MD AF Schmitz, TL Davies, MA Kennedy, MD TI Tool point frequency response prediction for high-speed machining by RCSA SO JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID CHATTER AB The implementation of high-speed machining for the manufacture of discrete parts requires accurate knowledge of the system dynamics. We describe the application of receptance coupling substructure analysis (RCSA) to the analytic prediction of the tool point dynamic response by combining frequency response measurements of individual components through appropriate connections. Experimental verification of the receptance coupling method for various tool geometries (e.g., diameter and length) and holders (HSK 63A collet and shrink fit) is given. Several experimental results are, presented to demonstrate the practical applicability of the proposed method for chatter stability prediction in milling. C1 Natl Inst Stand & Technol, Mfg Metrol Div, Gaithersburg, MD 20899 USA. RP Schmitz, TL (reprint author), Natl Inst Stand & Technol, Mfg Metrol Div, 100 Bur Dr,MS 8220, Gaithersburg, MD 20899 USA. NR 26 TC 91 Z9 101 U1 1 U2 23 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 1087-1357 J9 J MANUF SCI E-T ASME JI J. Manuf. Sci. Eng.-Trans. ASME PD NOV PY 2001 VL 123 IS 4 BP 700 EP 707 DI 10.1115/1.1392994 PG 8 WC Engineering, Manufacturing; Engineering, Mechanical SC Engineering GA 494WC UT WOS:000172308000021 ER PT J AU Gilsinn, DE Davies, MA Balachandran, B AF Gilsinn, DE Davies, MA Balachandran, B TI Stability of precision diamond turning processes that use round nosed tools SO JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB A system of retarded differential equations model is developed for a diamond-turning process with chip area cut by a round nosed tool. The results are presented in the form of stability charts that are found to be perturbed forms of those obtained for orthogonal cutting tools. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. RP Gilsinn, DE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 3 TC 4 Z9 4 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 1087-1357 J9 J MANUF SCI E-T ASME JI J. Manuf. Sci. Eng.-Trans. ASME PD NOV PY 2001 VL 123 IS 4 BP 747 EP 748 DI 10.1115/1.1373648 PG 2 WC Engineering, Manufacturing; Engineering, Mechanical SC Engineering GA 494WC UT WOS:000172308000026 ER PT J AU Harrison, DE Romea, RD Hankin, SH AF Harrison, DE Romea, RD Hankin, SH TI Central equatorial Pacific zonal currents. I: The Sverdrup balance, nonlinearity and tropical instability waves. Annual mean dynamics SO JOURNAL OF MARINE RESEARCH LA English DT Article ID MOMENTUM BALANCE; EDDY ENERGETICS; SEASONAL CYCLE; OCEAN; MODEL; ATLANTIC; UNDERCURRENT; VARIABILITY; FLUX AB Several recent observational studies of central Pacific equatorial current dynamics have suggested that, in the vertical integral between the surface and the thermocline, the linear equatorial Sverdrup balance holds. However, in a high vertical resolution ocean general circulation model, we find that nonlinearity is an order (1) element of the local and the vertically integrated balances on and near the equator at 140W. Although this OGCM has been used in many studies of the tropical Pacific, its equatorial zonal momentum equation balances have never been described in detail and compared with observations. We describe the annual mean balances here, identify the similarities and differences between the model balances and observational estimates of the balances, and discuss various reasons why the model and the observations may disagree in the respects that they are found to do so. The term balances vary strongly with latitude and depth: the system is nonlinear and three dimensional. There is little tendency for pairs of terms (e.g.. the meridional and vertical advection terms) to balance locally or in the vertical integral. Every term in the zonal momentum equation plays a role somewhere in the analysis region discussed here. Thus the generality of point estimates of these balances is small. The Tropical Instability Wave zonal momentum flux divergence, although not an 0(l) term in the balance, acts like a 'negative viscosity over the upper 40 m on the equator, its tendency is to drive westward flow. If the ocean balances resemble those of the model dynamics, gaining detailed perspective on the zonal balances will require a major observational effort. Because there is strong subseasonal and interannual variability of the flows in the central equatorial Pacific, time-mean balances are not simple to estimate, Further, special attention will have to be given to resolving the shears in the upper 50 m. because it is over these depths that the model and observational results differ most strongly. We suggest that the widely used technique of extrapolating the near-surface currents based on their shears in the uppermost bins of the ADCP profiles deserves careful scrutiny; subsampling the model flow profiles in this fashion leads to important errors. Until the strong vertically sheared very near-surface current field is observed accurately it will not be possible to determine if the model results are correct, but we suggest that the existing observational results should not be regarded as definitive. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. RP Harrison, DE (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI Harrison, Don/D-9582-2013 NR 24 TC 8 Z9 8 U1 0 U2 4 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 NOV PY 2001 VL 59 IS 6 BP 895 EP 919 DI 10.1357/00222400160497706 PG 25 WC Oceanography SC Oceanography GA 508MQ UT WOS:000173093200003 ER PT J AU Harrison, DE Romea, RD Vecchi, GA AF Harrison, DE Romea, RD Vecchi, GA TI Central equatorial Pacific zonal currents. II: The seasonal cycle and the boreal spring surface eastward surge SO JOURNAL OF MARINE RESEARCH LA English DT Article ID TROPICAL INSTABILITY WAVES; MOMENTUM BALANCE; NUMERICAL-MODEL; OCEAN; VARIABILITY; ENERGETICS; ATLANTIC; GENERATION AB The seasonally averaged zonal momentum equation tendencies at 140W are studied in a high-resolution primitive equation ocean general circulation model simulation of the tropical Pacific. The model experiment, forced by climatological monthly average wind-stress, reproduces well the observed boreal springtime eastward surge of the normally westward surface flow, as well as many features of the acceleration and deceleration between the surface and 200 m between January and October. We present each of the zonal momentum equation tendency terms for the depth range 0-160 m, but our discussion focuses on the behavior of the boreal springtime near-surface flow, perhaps the most distinctive feature of the seasonal cycle, The eastward surface surge in boreal spring depends crucially on the springtime weakening of the otherwise westward tendency from tropical instability waves (TIWs). The TIW effects, together with the eastward tendency from the seasonal weakening of the easterly wind-stress, drive the eastward surface current surge. Although the 'negative viscosity' effect of the TIWs is small in the annual mean, as we have previously shown, its seasonal variation is necessary to the surface flow reversal and eastward surge in this model. A series of experiments, each with weaker TIWs than its predecessor, shows a progressive weakening and eventual absence of springtime eastward surface flow, supporting the above analysis. The seasonal zonal velocity accelerations and decelerations are small compared with the terms in the zonal momentum equation; these terms must be known to an accuracy of at least 10 cm s(-1) month(-1) (2-5% of the largest terms) if a meaningful budget is to be obtained. This is a strong constraint that must be planned for in future observational studies. We find that nonlinear terms are O(1) in the vertically-integrated balance as well as the local balance, in contrast with some recent observational estimates, Extrapolated velocity errors, neglected terms, data processing assumptions. and crude finite-differencing in the observational studies may account for the differences, as appeared to be the case in the annual mean balances. The model dynamical balances cannot be reproduced if the methods used to analyze observational data are applied to the model output fields. Very near-surface currents must be measured rather than extrapolated if the ocean shear is similar to that of the model flows. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. RP Harrison, DE (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI Vecchi, Gabriel/A-2413-2008; Harrison, Don/D-9582-2013 OI Vecchi, Gabriel/0000-0002-5085-224X; NR 25 TC 7 Z9 7 U1 0 U2 1 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 NOV PY 2001 VL 59 IS 6 BP 921 EP 948 DI 10.1357/00222400160497715 PG 28 WC Oceanography SC Oceanography GA 508MQ UT WOS:000173093200004 ER PT J AU Kramer, DE Volinsky, AA Moody, NR Gerberich, WW AF Kramer, DE Volinsky, AA Moody, NR Gerberich, WW TI Substrate effects on indentation plastic zone development in thin soft films SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID WEAR-RESISTANT COATINGS; WT-PERCENT-SI; MECHANICAL-PROPERTIES; SINGLE-CRYSTAL; MICROINDENTATION MECHANICS; HARDNESS; SILICON; DEFORMATION; LOAD; MICROSCOPY AB Plastic zone evolution in Al-2 wt% Si metal films on silicon and sapphire substrates was studied using nanoindentation and atomic force microscopy (AFM). AFM was used to measure the extent of plastic pileup, which is a measure of the plastic zone radius in the film. It was found that the plastic zone size develops in a self-similar fashion with increasing indenter penetration when normalized by the contact radius, regardless of film hardness or underlying substrate properties. This behavior was used to develop a hardness model that uses the extent of the plastic zone radius to calculate a core region within the indenter contact that is subject to an elevated contact pressure. AFM measurements also indicated that as film thickness decreases, constraint imposed by the indenter and substrate traps the film thereby reducing the pileup volume. C1 Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. Sandia Natl Labs, Div Mat Reliabil, Livermore, CA 94551 USA. RP Kramer, DE (reprint author), Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RI Volinsky, Alex/A-7974-2009; OI Volinsky, Alex/0000-0002-8520-6248 NR 37 TC 59 Z9 61 U1 1 U2 13 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD NOV PY 2001 VL 16 IS 11 BP 3150 EP 3157 DI 10.1557/JMR.2001.0434 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 489YL UT WOS:000172020600021 ER PT J AU Tewari, YB Bunk, DM AF Tewari, YB Bunk, DM TI Thermodynamics of the lipase-catalyzed esterification of glycerol and n-octanoic acid in organic solvents and in the neat reaction mixture SO JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC LA English DT Article; Proceedings Paper CT Martire Symposium CY MAY 04, 2001 CL GEORGETOWN UNIV, WASHINGTON, D.C. HO GEORGETOWN UNIV DE dioctanoyl glycerol; equilibrium constants; esterification; glycerol; lipase; monooctanoyl glycerol; n-octanoic acid; triooctanoyl glycerol ID EQUILIBRIUM POSITION; 1-DODECANOIC ACID; HYDROLYSIS; TRANSESTERIFICATION; (-)-MENTHOL; MEDIA; WATER; ESTER AB The thermodynamics of the lipase-catalyzed esterification of glycerol with n-octanoic acid have been investigated with acetonitrile, benzene, and toluene as solvents and in the neat reaction mixture (no organic solvent added). This esterification reaction leads to five products: 1-monooctanoyl glycerol, 2-monooctanoyl glycerol, 1,2-dioctanoyl glycerol, 1,3-dioctanoyl glycerol and 1,2,3-trioctanoyl glycerol. This, in turn leads to a total of 12 reactions. Values of the equilibrium constants for these reactions have been measured (HPLC, GC, and LC/MS) at 37 degreesC in the above mentioned media. The equilibrium constants range from 0.9 to 20.7, 0.20 to 8.0, 0.23 to 10.0, and 0.57 to 2.2 in acetonitrile, benzene, toluene, and neat media, respectively. Relative standard molar Gibbs free energies of formation Delta (f)G(m)(0) of 1-monooctanoyl glycerol, 2-monooctanoyl glycerol, 1,2-dioctanoyl glycerol, 1,3-dioctanoyl glycerol and 1,2,3-trioctanoyl glycerol in the organic solvents and in the neat reaction mixture have been calculated and used to compactly summarize the thermodynamics of these reactions. The results show an approximate correlation with the permittivities of the solvents. Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Tewari, YB (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. NR 28 TC 15 Z9 15 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1381-1177 J9 J MOL CATAL B-ENZYM JI J. Mol. Catal. B-Enzym. PD NOV 1 PY 2001 VL 15 IS 4-6 BP 135 EP 145 DI 10.1016/S1381-1177(01)00016-9 PG 11 WC Biochemistry & Molecular Biology; Chemistry, Physical SC Biochemistry & Molecular Biology; Chemistry GA 483WE UT WOS:000171658200004 ER PT J AU Fraser, GT Suenram, RD Lugez, CL AF Fraser, GT Suenram, RD Lugez, CL TI Investigation of conformationally rich molecules: Rotational spectra of fifteen conformational isomers of 1-octene SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSFORM MICROWAVE SPECTROMETER; SEEDED SUPERSONIC JETS; QUANTUM-CHEMISTRY; HIGH-RESOLUTION; FORCE-FIELD; GAS-PHASE; CONFORMERS; SPECTROSCOPY; RELAXATION; TRYPTOPHAN AB The rotational spectra of 15 conformational isomers of 1-octene have been measured in a molecular beam at a rotational temperature of less than 2 K using a pulsed-nozzle Fourier transform microwave spectrometer. The transition assignments are guided by rotational constant calculations based on moderate-level ab initio theory and on the relative energy minima on the MM3. molecular-mechanics force field. The number of conformers identified is slightly more than 10% of the 131 predicted from the MM3 molecular-mechanics force field of Allinger et al. Fourteen of the observed conformers are identified with 14 of the 15 lowest energy minima predicted from the MM3 molecular-mechanics force field. The observation of such a large number of conformers, with a MM3 calculated energy spread of 365 cm(-1) for this subset of 14, is a consequence of the minimal conformational cooling ih the molecular-beam expansion. Limiting this cooling are the relatively high barriers separating the conformers compared to the thermal energy, kT, of the preexpansion gas. In some cases, primarily for the higher energy conformers, the need to cross multiple internal-rotation barriers provides an additional bottleneck for conformer relaxation. The rotational spectra furnish values for the principal moments of inertia, which are sensitive to the conformational geometry and can be compared with predictions from future high-level ab initio calculations. Assuming no conformer relaxation in the expansion allows the use of the transition-intensity data to estimate the energy ordering of the conformers. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Fraser, GT (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 23 TC 26 Z9 26 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 NOV 1 PY 2001 VL 105 IS 43 BP 9859 EP 9864 DI 10.1021/jp010693l PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 489YG UT WOS:000172020100007 ER PT J AU Fraser, GT Suenram, RD Lugez, CL AF Fraser, GT Suenram, RD Lugez, CL TI Investigation of conformationally rich molecules: Rotational spectra of fifteen conformational isomers of 1-octene. SO JOURNAL OF PHYSICAL CHEMISTRY B 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 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD NOV 1 PY 2001 VL 105 IS 43 BP 22A EP 22A PG 1 WC Chemistry, Physical SC Chemistry GA 489YH UT WOS:000172020200045 ER PT J AU Greenberg, CC Foster, MD Turner, CM Corona-Galvan, S Cloutet, E Quirk, RP Butler, PD Hawker, C AF Greenberg, CC Foster, MD Turner, CM Corona-Galvan, S Cloutet, E Quirk, RP Butler, PD Hawker, C TI Effective interaction parameter between branched and linear polystyrene SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article; Proceedings Paper CT Meeting of the American-Physical-Society CY MAR, 2001 CL SEATTLE, WASHINGTON SP Amer Phys Soc DE star polymers; long-chain branching; phase behavior; small-angle neutron scattering (SANS); thermodynamics ID ANGLE NEUTRON-SCATTERING; SATURATED-HYDROCARBON POLYMERS; PHASE-BEHAVIOR; THERMODYNAMIC INTERACTIONS; POLYOLEFIN BLENDS; LIQUID STRUCTURE; MIXING BEHAVIOR; THETA-STATES; MISCIBILITY; POLYBUTADIENE AB Values of the effective interaction parameter (X) between regular, long-branched polystyrene chains and their linear analogues were measured with small-angle neutron scattering for several star-branched chains and one comb-type polymer. The contribution to this interaction due to architecture alone increases monotonically with star functionality for the set of polymers studied here. The interaction appears to be less sensitive to variations in arm size than would be expected from fluctuation theory predictions by G. H. Fredrickson, A. Liu, and F. S. Bates (Macromolecules 1994, 27, 2503) for a purely entropic interaction due to architecture. The change in chi with the volume fraction of the star in the blend is in agreement with the theory, however. The magnitudes of the interaction in the star/linear blends are small enough that bulk phase separation is unlikely, whereas that in the comb/linear blend is about 20 times higher for the same number of arms. Thus, bulk phase separation can be readily expected for comb/linear blends at commercially relevant values of molecular weights. (C) 2001 John Wiley & Sons, Inc. C1 Univ Akron, Maurice Morton Inst Polymer Sci, Akron, OH 44325 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. RP Foster, MD (reprint author), Univ Akron, Maurice Morton Inst Polymer Sci, Akron, OH 44325 USA. RI Butler, Paul/D-7368-2011; Cloutet, Eric/B-3487-2014 OI Cloutet, Eric/0000-0002-5616-2979 NR 37 TC 30 Z9 30 U1 0 U2 16 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD NOV 1 PY 2001 VL 39 IS 21 BP 2549 EP 2561 DI 10.1002/polb.10017 PG 13 WC Polymer Science SC Polymer Science GA 484DJ UT WOS:000171674700001 ER PT J AU Lawn, BR Deng, Y Thompson, VP AF Lawn, BR Deng, Y Thompson, VP TI Use of contact testing in the characterization and design of all-ceramic crownlike layer structures: A review SO JOURNAL OF PROSTHETIC DENTISTRY LA English DT Article; Proceedings Paper CT 49th Annual Meeting of the American-Academy-of-Fixed-Prosthodontics CY FEB 25, 2000 CL CHICAGO, IL SP Amer Acad Fixed Prosthodont ID STRENGTH DEGRADATION; DENTAL CERAMICS; GLASS-CERAMICS; MECHANICAL-PROPERTIES; CLINICAL-EVALUATION; INDENTATION DAMAGE; HERTZIAN CONTACTS; BRITTLE COATINGS; GENERAL-PRACTICE; CYCLIC FATIGUE AB Ceramic-based crowns, particularly molar crowns, can fail prematurely from accumulation of fracture and other damage in continual occlusal contact. Damage modes depend on ceramic types (especially microstructures), flaw states, loading conditions, and geometric factors. These damage modes can be simulated and characterized in the laboratory with the use of Hertzian contact testing on monolayer, bilayer, and trilayer structures to represent important aspects of crown response in oral function. This article reviews the current dental materials knowledge base of clinically relevant contact-induced damage in ceramic-based layer structures in the context of all-ceramic crown lifetimes. It is proposed that simple contact testing protocols that make use of sphere indenters on model flat, ceramic-based layer structures-ceramic/polymer bilayers (simulating monolithic ceramic crowns on dentin) and ceramic/ceramic/polymer trilayers (simulating veneer/core all-ceramic crowns on dentin)-can provide useful relations for predicting critical occlusal loads to induce lifetime-threatening fracture. It is demonstrated that radial cracking from the lower core layer surface is the dominant failure mode for ceramic layer thicknesses much below I mm. Such an approach may be used to establish a scientific, materials-based foundation for designing next-generation crown layer structures. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Univ Med & Dent New Jersey, Dent Sch, Dept Prosthidont & Biomat, Newark, NJ 07103 USA. RP Lawn, BR (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. EM brian.lawn@nist.gov OI Thompson, Van P/0000-0003-0033-0344 FU NIDCR NIH HHS [P01 DE10976] NR 60 TC 150 Z9 155 U1 1 U2 16 PU MOSBY-ELSEVIER PI NEW YORK PA 360 PARK AVENUE SOUTH, NEW YORK, NY 10010-1710 USA SN 0022-3913 EI 1097-6841 J9 J PROSTHET DENT JI J. Prosthet. Dent. PD NOV PY 2001 VL 86 IS 5 BP 495 EP 510 DI 10.1067/mpr.2001.119581 PG 16 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 499FZ UT WOS:000172561600008 PM 11725278 ER PT J AU Piermarini, GJ AF Piermarini, GJ TI High pressure X-ray crystallography with the diamond cell at NIST/NBS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE crystallography; diamond anvil cell (DAC); high pressure; hydrostaticity; polycrystalline; ruby pressure measurement; single crystal ID ANVIL CELL; KBAR; CRYSTAL; PHASE; LINE AB Scientists in the Crystallography Section at NIST/NBS made several outstanding contributions which greatly promoted the development and advancement of high pressure x-ray crystallography during the second-half of the 20th century. These milestone achievements or firsts included: (1) the invention of the lever-arm type diamond anvil cell (DAC) in 1958; (2) the development of DAC technology for powder x-ray diffraction at high pressure in 1960; (3) the introduction of DAC methodology for single crystal x-ray diffraction at high pressure in 1964; (4) the invention of the optical fluorescence ruby method of pressure measurement in 1971; and (5) the discovery of hydrostatic pressure-transmitting media useful to unprecedented pressures for that time. These achievements provided the spark that ignited the explosion of activity in high pressure research that occurred in laboratories throughout the world during the latter part of the 20th century. It is still going on, unabated, today. An estimated 5000 DACs were built during the last 40 years. C1 NIST, NBS, Gaithersburg, MD 20899 USA. RP NIST, NBS, Gaithersburg, MD 20899 USA. EM gasper.piermarini@nist.gov NR 28 TC 15 Z9 15 U1 4 U2 14 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 889 EP 920 PG 32 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000001 PM 27500054 ER PT J AU Santoro, A AF Santoro, A TI Past and present crystallographic work at the NBS/NIST reactor SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE collaborative research; historical research highlights; NBS Reactor; profile refinement; single-crystal and powder neutron diffraction; theoretical crystal geometry ID NEUTRON-POWDER-DIFFRACTION; HIGH-TC SUPERCONDUCTIVITY; INSERTED METAL-OXIDES; BA-CU OXIDES; CRYSTAL-STRUCTURE; ZEOLITE-RHO; MAGNETIC-PROPERTIES; ROOM-TEMPERATURE; PHASE-TRANSITION; O SYSTEM AB Neutron diffraction at NBS/NIST started soon after the NBS reactor became operational in the summer of 1969. Since that time, literally hundreds of crystal structures have been determined and refined using single crystal and powder neutron diffraction data, collected with a variety of instruments. This work has been usually done in collaboration with other NBS/NIST divisions and/or universities and industrial laboratories. In parallel with the technical developments and the experimental work, also theoretical aspects of crystal geometry have been clarified, and significant improvements in the techniques of profile refinements have been made. It is therefore understandable that a comprehensive description of all the crystallographic studies carried out up to the present is impossible under the constraints of space and time imposed by a review of this type, and, in the following sections, we will limit ourselves to give, only a brief account of the topics which, in our opinion, represent the highlights of the work carried out at the reactor. C1 NIST, Mat Sci & Engn Lab, Ctr Neuron Res, Gaithersburg, MD 20899 USA. RP NIST, Mat Sci & Engn Lab, Ctr Neuron Res, Gaithersburg, MD 20899 USA. NR 89 TC 1 Z9 1 U1 0 U2 10 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 921 EP 952 PG 32 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000002 PM 27500055 ER PT J AU Lynn, JW Borchers, JA Huang, Q Santoro, A Erwin, RW AF Lynn, JW Borchers, JA Huang, Q Santoro, A Erwin, RW TI Magnetic structure determinations at NBS/NIST SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Review DE applied magnetic field; magnetic multilayers; magnetic order parameter; magnetic structure; magnetic superconductors; magnetic symmetry; neutron diffraction; polarization analysis; pressure dependence ID COUPLED FE/CR(001) SUPERLATTICES; BIASED FE3O4/COO SUPERLATTICES; HOLMIUM-RICH (ER1-XHOX)RH4B4; NEUTRON-POWDER-DIFFRACTION; ER THIN-FILMS; SPIN DYNAMICS; RARE-EARTH; ANTIFERROMAGNETIC ORDER; PHASE-TRANSITIONS; NANOCRYSTALLINE CHROMIUM AB Magnetic neutron scattering plays a central role in determining and understanding the microscopic properties of a vast variety of magnetic systems, from the fundamental nature, symmetry, and dynamics of magnetically ordered materials to elucidating the magnetic characteristics essential in technological applications. From the early days of neutron scattering measurements at NBS/NIST, magnetic diffraction studies have been a central theme involving many universities, industrial and government labs from around the United States and worldwide. Such measurements have been used to determine the spatial arrangement and directions of the atomic magnetic moments, the atomic magnetization density of the individual atoms in the material, and the value of the ordered moments as a function of thermodynamic parameters such as temperature, pressure, and applied magnetic field. These types of measurements have been carried out on single crystals, powders, thin films, and artificially grown multilayers, and often the information collected can be obtained by no other experimental technique. This article presents, in an historical perspective, a few examples of work carried out at the NIST Center for Neutron Research (NCNR), and discusses the key role that the Center can expect to play in future magnetism research. C1 NIST, Mat Sci & Engn Lab, Ctr Neuron Res, Gaithersburg, MD 20899 USA. RP Lynn, JW (reprint author), NIST, Mat Sci & Engn Lab, Ctr Neuron Res, Gaithersburg, MD 20899 USA. EM jeff.lynn@nist.gov; julie.borchers@nist.gov; qing.huang@nist.gov; ross.erwin@nist.gov NR 113 TC 0 Z9 0 U1 3 U2 16 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 953 EP 963 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000003 PM 27500056 ER PT J AU Toby, BH AF Toby, BH TI Investigations of zeolitic materials at the NIST Center for Neutron Research SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE crystallography; microporous materials; neutron diffraction; powder diffraction; zeolite ID RHO TOPOLOGY; ALUMINOGERMANATE; LITHOSILICATE; FLEXIBILITY; EXCHANGE AB Crystallographic studies of four zeolitic materials using neutron powder diffraction data are presented. In most cases, these projects benefited from the combined use of neutron and x-ray measurements. C1 NIST, Gaithersburg, MD 20899 USA. RP Toby, BH (reprint author), NIST, Gaithersburg, MD 20899 USA. RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 17 TC 1 Z9 1 U1 0 U2 11 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 965 EP 973 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000004 PM 27500057 ER PT J AU Cahn, JW AF Cahn, JW TI Quasicrystals SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE aperiodic crystals; new branch of crystallography; quasicrystals ID AL-CU-FE; QUASI-CRYSTAL; TRANSLATIONAL SYMMETRY; STRUCTURE REFINEMENT; APPROXIMANTS; ALLOY AB The discretely diffracting aperiodic crystals termed quasicrystals, discovered at NBS in the early 1980s, have led to much interdisciplinary activity involving mainly materials science, physics, mathematics, and crystallography. It led to a new understanding of how atoms can arrange themselves, the role of periodicity in nature, and has created a new branch of crystallography. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Cahn, JW (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 43 TC 6 Z9 6 U1 1 U2 9 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 975 EP 982 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000005 PM 27500058 ER PT J AU Mighell, AD AF Mighell, AD TI Lattice symmetry and identification - The fundamental role of reduced cells in materials characterization SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE crystallography; identification; mathematical lattices; reduction; symmetry determination AB In theory, physical crystals can be represented by idealized mathematical lattices. Under appropriate conditions, these representations can be used for a variety of purposes such as identifying, classifying, and understanding the physical properties of materials. Critical to these applications is the ability to construct a unique representation of the lattice. The vital link that enabled this theory to be realized in practice was provided by the 1970 paper on the determination of reduced cells. This seminal paper led to a mathematical approach to lattice analysis initially based on systematic reduction procedures and the use of standard cells. Subsequently, the process evolved to a matrix approach based on group theory and linear algebra that offered a more abstract and powerful way to look at lattices and their properties. Application of the reduced cell to both database work and laboratory research at NIST was immediately successful. Currently, this cell and/or procedures based on reduction are widely and routinely used by the general scientific community: (i) for calculating standard cells for the reporting of crystalline materials, (ii) for classifying materials, (iii) in crystallographic database work (iv) in routine x-ray and neutron diffractometry, and (v) in general crystallographic research. Especially important is its use in symmetry determination and in identification. The focus herein is on the role of the reduced cell in lattice symmetry determination. C1 NIST, Gaithersburg, MD 20899 USA. RP Mighell, AD (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 31 TC 13 Z9 13 U1 1 U2 12 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 983 EP 995 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000006 PM 27500059 ER PT J AU Bendersky, LA Gayle, FW AF Bendersky, LA Gayle, FW TI Electron diffraction using transmission electron microscopy SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE crystal structure; crystallography; defects; electron diffraction; phase transitions; quasicrystals; transmission electron microscopy ID AL-NB SYSTEM; TRANSLATIONAL SYMMETRY; PHASE-TRANSFORMATIONS; DECAGONAL PHASE; ALLOY; MN; SECTION; OXIDES; GROWTH; FILMS AB Electron diffraction via the transmission electron microscope is a powerful method for characterizing the structure of materials, including perfect crystals and defect structures. The advantages of electron diffraction over other methods, e. g., x-ray or neutron, arise from the extremely short wavelength ( approximate to2 pm), the strong atomic scattering, and the ability to examine tiny volumes of matter ( approximate to nm(3)). The NIST Materials Science and Engineering Laboratory has a history of discovery and characterization of new structures through electron diffraction, alone or in combination with other diffraction methods. This paper provides a survey of some of this work enabled through electron microscopy. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NIST, Div Met, Mat Struct & Characterizat Grp, Gaithersburg, MD 20899 USA. RP Bendersky, LA (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 52 TC 18 Z9 18 U1 0 U2 15 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 997 EP 1012 PG 16 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000007 PM 27500060 ER PT J AU Wong-Ng, W McMurdie, HF Hubbard, CR Mighell, AD AF Wong-Ng, W McMurdie, HF Hubbard, CR Mighell, AD TI JCPDS-ICDD Research Associateship (cooperative program with NBS/NIST) SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CD-ROM data storage; powder data evaluation; Research Associateship; SRMs for powder diffraction; standard powder x-ray diffraction patterns ID PATTERNS AB The Research Associateship program of the Joint Committee on Powder Diffraction-International Centre for Diffraction Data (JCPDS-ICDD, now known as the ICDD) at NBS/NIST was a long standing (over 35 years) successful industry-government cooperation. The main mission of the Associateship was to publish high quality x-ray reference patterns to be included in the Powder Diffraction File (PDF). The PDF is a continuing compilation of patterns gathered from many sources, compiled and published by the ICDD. As a result of this collaboration, more than 1500 high quality powder diffraction patterns, which have had a significant impact on the scientific community, were reported. In addition, various research collaborations with NBS/NIST also led to the development of several standard reference materials SRMs) for instrument calibration and quantitative analyses, and computer software for data collection, calibration, reduction, for the editorial process of powder pattern publication, analysis of powder data, and for quantitative analyses. This article summarizes information concerning the JCPDS-ICDD organization, the Powder Diffraction File (PDF), history and accomplishments of the JCPDS-ICDD Research Associateship. C1 NIST, Div Ceram, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Wong-Ng, W (reprint author), NIST, Div Ceram, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 84 TC 16 Z9 17 U1 0 U2 14 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 1013 EP 1028 PG 16 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000008 PM 27500061 ER PT J AU Chow, LC Takagi, S AF Chow, LC Takagi, S TI A natural bone cement - A laboratory novelty led to the development of revolutionary new biomaterials SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE biomaterial; bone graft; bone repair; dicalcium phosphate anhydrous; hydroxyapatite; self-setting calcium phosphate cement; tetracalcium phosphate ID CALCIUM-PHOSPHATE CEMENT; HYDROXYAPATITE CEMENT; RECONSTRUCTION; DEFECTS; SURGERY; REPAIR AB Research on calcium phosphate chemistry at NIST led to the discovery of the worlds first self-hardening calcium phosphate cements (CPC) in 1987. Laboratory, animal, and clinical studies were conducted to develop CPC into clinically useful biomaterials. The combination of self-hardening capability and high biocompatibility makes CPC a unique material for repairing bone defects. Near perfect adaptation of the cement to the tissue surfaces in a defect, and a gradual resorption followed by new bone formation are some of the other distinctive advantages of this biomaterial. In 1996 a CPC, consisting of tetracalcium phosphate and dicalcium phosphate anhydrous, was approved by the Food and Drug Administration ( FDA) for repairing cranial defects in humans, thus becoming the first material of its kind available for clinical use. This paper will review the course of the development, the physical and chemical properties, and clinical applications of CPC. C1 NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Dent Chem Div, Gaithersburg, MD 20899 USA. NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Cariol Div,Polymer Div,Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Chow, LC (reprint author), NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Dent Chem Div, Gaithersburg, MD 20899 USA. EM laurence.chow@nist.gov; shozo.takagi@nist.gov FU NIDCR NIH HHS [R01 DE011789] NR 31 TC 35 Z9 36 U1 4 U2 18 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 1029 EP 1033 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000009 PM 27500062 ER PT J AU Mathew, M Takagi, S AF Mathew, M Takagi, S TI Structures of biological minerals in dental research SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE biominerals; calcium phosphates; crystal structure; fluorapatite; glaserite; hydroxyapatite; octacalcium phosphate ID OCTACALCIUM PHOSPHATE; CRYSTAL-STRUCTURE; CALCIUM-PHOSPHATE; APATITES; OH; CL; CHEMISTRY; ENAMEL; SYSTEM AB Structural features of some calcium phosphates of biological interest are described. Structure of hydroxyapatite (OHAp), considered as the prototype for the inorganic component of bones and teeth is discussed with respect to the kinds and locations of ionic substitutions. Octacalcium phosphate ( OCP), is a probable precursor in biological mineralization. OCP has a layer type structure, with one layer quite similar to that of OHAp and the other, a hydrated layer consisting of more widely spaced Ca, and PO4 ions and the water molecules. The closeness of fit in the apatitic layers of OCP and OHAp accounts for the epitaxial, interlayered mixtures formed by these compounds and the in situ conversion of OCP to OHAp. Possible roles of OCP in biological mineralization are discussed. C1 NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Dent Crystallog Div, Gaithersburg, MD 20899 USA. NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Cariol Div, Gaithersburg, MD 20899 USA. RP Mathew, M (reprint author), NIST, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Dent Crystallog Div, Gaithersburg, MD 20899 USA. NR 44 TC 96 Z9 100 U1 4 U2 26 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 1035 EP 1044 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000010 PM 27500063 ER PT J AU Munro, RG AF Munro, RG TI NIST materials properties databases for advanced ceramics SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ceramics; database; evaluated data; materials properties; mechanical properties; physical properties; structural ceramics; superconductivity; thermal properties ID ORTHORHOMBIC YBA2CU3OX AB The NIST Ceramics Division maintains two databases on the physical, mechanical, thermal, and other properties of high temperature superconductors and structural ceramics. Crystallographic data are featured prominently among the physical property data and serve several important functions in the classification and evaluation of the property values. The scope of materials, properties, and data evaluation protocols are discussed for the two databases. C1 NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. RP Munro, RG (reprint author), NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. NR 9 TC 2 Z9 2 U1 1 U2 9 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 1045 EP 1050 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000011 PM 27500064 ER PT J AU Stutzman, P AF Stutzman, P TI Contributions of NIST/NBS researchers to the crystallography of construction materials SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE cement; cement clinker; concrete; construction materials; durability; performance; materials science; stone AB For more than 100 years, the primary theme underlying the NBS/NIST staff contribution to the crystallography of building materials has been the development of an improved understanding of concrete materials performance. Over that time period, portland cement concrete has become one of the most important of our construction materials for roads, buildings, and other large municipal structures. At the beginning of the 20th century our understanding of portland cement composition, performance, use in concrete, and how the concrete performs in harsh environments was lacking. The efforts of NIST have served to advance construction materials science and technology through the combined efforts of experimental, field study, and theoretical computational materials science. One major achievement in the late 1920s, derived from studies on phase equilibria in cement clinker, allows calculation of potential cement clinker composition. Known as the Bogue calculation, this continues to be an essential tool in cement plant process control to this day. Additionally, contributions of NIST scientists to our knowledge of the chemistry and nature of cement hydration products have been crucial in our understanding of cement hydration and concrete durability. Today, computational materials science is a rapidly developing discipline, and NIST is developing tools incorporating predictive models aided by empirical studies. Examples include a computer-integrated knowledge system for prediction and optimization of performance and life-cycle cost of high performance concrete and the Virtual Cement and Concrete Testing Laboratory. Understanding the relationships between material and performance properties has not been confined only to portland cements. One of the longest running experiments at NIST, the stone test wall, has stood for over 50 years as one of the worlds largest single collections of building stone, and is invaluable for studying weathering effects associated with stone mineralogy and texture. Standards development has also been promoted through participation on ASTM subcommittees on stone, cement, and concrete. The Cement and Concrete Reference Laboratory, established in 1929, continues to provide testing and training for outside laboratories and maintains a historical record of test data on construction materials. C1 NIST, Bldg Mat Div, Fire Res Lab, Gaithersburg, MD 20899 USA. RP Stutzman, P (reprint author), NIST, Bldg Mat Div, Fire Res Lab, Gaithersburg, MD 20899 USA. NR 73 TC 0 Z9 0 U1 0 U2 7 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 1051 EP 1061 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000012 PM 27500065 ER PT J AU Vaudin, MD AF Vaudin, MD TI Crystallographic texture in ceramics and metals SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE bulk and thin film samples; ceramics; crystallographic texture; metals; powder x-ray diffractometer AB Preferred crystallographic orientation, or texture, occurs almost universally, both in natural and man-made systems. Many components and devices in electronic and magnetic systems are fabricated from materials that have crystallographic texture. With the rapidly increasing use of thin film technology, where sharp axisymmetric crystallographic texture normal to the film plane is frequently observed, the occurrence and impact of texture are rising. Thin film applications in which the texture of the material plays a key role in determining properties and performance are broad: complex oxides in random access memory devices, ZnO thin film resonators for cell phone applications, metallic alloys in magnetic recording media, and Al and Cu interconnects in integrated circuits are but a few examples. Texture is established during the synthesis or post-synthesis heat treatment of a material and thus has a strong dependence upon processing history. Accurate measurement of texture is not simple and a variety of tools and approaches are being actively employed in texture studies. X-ray, neutron and electron diffraction based techniques are practiced around the world at varying levels of complexity with regard to equipment and analysis methods. Despite the well-documented existence of these varied approaches, many reported texture measurements on electronic materials are based solely on the relative intensities of conventional theta-2theta x-ray diffraction peaks, which typically yield inaccurate results. NIST has developed quantitative texture measurement techniques that employ equipment commonly available in most industrial and academic settings. A number of examples of texture measurement in ceramic and metal systems will be presented, taken from the historical development and application of these techniques at NIST over the past 7 years. C1 NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. RP Vaudin, MD (reprint author), NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. NR 6 TC 4 Z9 5 U1 0 U2 12 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 1063 EP 1069 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000013 PM 27500066 ER PT J AU Wong-Ng, W Siegrist, T De Titta, GT Finger, LW Evans, HT Gabe, EJ Enright, GD Armstrong, JT Levenson, M Cook, LP Hubbard, CR AF Wong-Ng, W Siegrist, T De Titta, GT Finger, LW Evans, HT Gabe, EJ Enright, GD Armstrong, JT Levenson, M Cook, LP Hubbard, CR TI Standard Reference Material (SRM 1990) for single crystal diffractometer alignment SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE alignment standard; Cr-content; international round robin; NIST SRM 1990; ruby spheres; single crystal x-ray diffractometers ID CONSTANTS AB An international project was successfully completed which involved two major undertakings: (1) a round-robin to demonstrate the viability of the selected standard and ( 2) the certification of the lattice parameters of the SRM 1990, a Standard Reference Material(R) for single crystal diffractometer alignment. This SRM is a set of approximate to 3500 units of Cr-doped Al2O3, or ruby spheres [ (0.420.011 mole fraction % C ( expanded uncertainty)]. The round-robin consisted of determination of lattice parameters of a pair of crystals: the ruby sphere as a standard, and a zeolite reference to serve as an unknown. Fifty pairs of crystals were dispatched from Hauptman-Woodward Medical Research Institute to volunteers in x-ray laboratories world-wide. A total of 45 sets of data was received from 32 laboratories. The mean unit cell parameters of the ruby spheres was found to be a = 4.7608 Angstrom +/- 0.0062 Angstrom, and c = 12.9979 Angstrom +/- 0.020 Angstrom ( 95 % intervals of the laboratory means). The source of errors of outlier data was identified. The SRM project involved the certification of lattice parameters using four well-aligned single crystal diffractometers at ( Bell Laboratories) Lucent Technologies and at NRC of Canada ( 39 ruby spheres), the quantification of the Cr content using a combined microprobe and SEM/EDS technique, and the evaluation of the mosaicity of the ruby spheres using a double-crystal spectrometry method. A confirmation of the lattice parameters was also conducted using a Guinier-Hagg camera. Systematic corrections of thermal expansion and refraction corrections were applied. These rubies are rhombohedral, with space group R 3 c. The certified mean unit cell parameters are a = 4.76080 +/- 0.00029 Angstrom, and c = 12.99568 Angstrom +/- 0.00087 Angstrom ( expanded uncertainty). These certified lattice parameters fall well within the results of those obtained from the international round-robin study. The Guinier-Hagg transmission measurements on five samples of powdered rubies ( a = 4.7610 Angstrom +/- 0.0013 Angstrom, and c = 12.9954 Angstrom +/- 0.0034 Angstrom) agreed well with the values obtained from the single crystal spheres. C1 NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. Lund Univ, S-22100 Lund, Sweden. Hauptman Woodward Med Res Inst, Buffalo, NY 14203 USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. US Geol Survey, Reston, VA 22092 USA. Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. NIST, Surface & Microanaly Sci Div, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Oak Ridge Natl Lab, Div Met & Ceram, Diffract & Thermophys Properties Grp, Oak Ridge, TN 37831 USA. RP Wong-Ng, W (reprint author), NIST, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. NR 39 TC 9 Z9 9 U1 0 U2 10 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 1071 EP 1095 PG 25 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000014 PM 27500067 ER PT J AU Wong-Ng, W Roth, RS Vanderah, TA McMurdie, HF AF Wong-Ng, W Roth, RS Vanderah, TA McMurdie, HF TI Phase equilibria and crystallography of ceramic oxides SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Review DE ceramic oxides; crystal chemistry; crystallography; electronic materials; historical development; phase equilibria ID X-RAY-DIFFRACTION; INSERTED METAL-OXIDES; TERNARY-SYSTEM BAO-TIO2-NB2O5; CA-CU-O; CRYSTAL-CHEMISTRY; BARIUM POLYTITANATES; SINGLE-CRYSTAL; BAO-FE2O3-TIO2 SYSTEM; SUPERCONDUCTOR; FIELD AB Research in phase equilibria and crystallography has been a tradition in the Ceramics Division at National Bureau of Standards/National Institute of Standatrds and Technology (NBS/NIST) since the early thirties. In the early years, effort was concentrated in areas of Portland cement, ceramic glazes and glasses, instrument bearings, and battery materials. In the past 40 years, a large portion of the work was related to electronic materials, including ferroelectrics, piezoelectrics, ionic conductors, dielectrics, microwave dielectrics, and high-temperature superconductors. As a result of the phase equilibria studies, many new compounds have been discovered. Some of these discoveries have had a significant impact on US industry. Structure determinations of these new phases have often been carried out as a joint effort among NBS/NIST colleagues and also with outside collaborators using both single crystal and neutron and x-ray powder diffraction techniques. All phase equilibria diagrams were included in Phase Diagrams for Ceramists, which are collaborative publications between The American Ceramic Society ( ACerS) and NBS/NIST. All x-ray powder diffraction patterns have been included in the Powder Diffraction File ( PDF). This article gives a brief account of the history of the development of the phase equilibria and crystallographic research on ceramic oxides in the Ceramics Division. Represented systems, particularly electronic materials, are highlighted. C1 NIST, Div Ceram, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NIST, Div Ceram, Phase Equilibria Grp, Gaithersburg, MD 20899 USA. RP Wong-Ng, W (reprint author), NIST, Div Ceram, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 130 TC 10 Z9 10 U1 3 U2 31 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 1097 EP 1134 PG 38 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000015 PM 27500068 ER PT J AU Long, GG Allen, AJ Black, DR Burdette, HE Fischer, DA Spal, RD Woicik, JC AF Long, GG Allen, AJ Black, DR Burdette, HE Fischer, DA Spal, RD Woicik, JC TI National Institute of Standards and Technology Synchrotron Radiation Facilities for Materials Science SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ceramics; materials science; metallurgy; polymers; semiconductors; synchrotron radiation; x-ray instrumentation ID X-RAY-SCATTERING; ABSORPTION FINE-STRUCTURE; SMALL-ANGLE-SCATTERING; STRAINED-SEMICONDUCTOR ALLOYS; BOND-LENGTH STRAIN; CRYSTAL-GROWTH; FILMS; GA1-XINXAS; GAAS(001); CAMERA AB Synchrotron Radiation Facilities, supported by the Materials Science and Engineering Laboratory of the National Institute of Standards and Technology, include beam stations at the National Synchrotron Light Source at Brookhaven National Laboratory and at the Advanced Photon Source at Argonne National Laboratory. The emphasis is on materials characterization at the microstructural and at the atomic and molecular levels, where NIST scientists, and researchers from industry, universities and government laboratories perform state-of-the-art x-ray measurements on a broad range of materials. C1 NIST, Div Ceram, Mat Microstruct Characterizat Grp, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Long, GG (reprint author), NIST, Div Ceram, Mat Microstruct Characterizat Grp, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI USAXS, APS/D-4198-2013 NR 39 TC 3 Z9 5 U1 0 U2 8 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 1141 EP 1154 PG 14 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000017 PM 27500070 ER PT J AU Gilliland, GL AF Gilliland, GL TI Macromolecular crystallography and structural biology databases a NIST SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Review DE macromolecular crystallography; neutron crystallography; protein crystallography; proteins; structural biology databases; x-ray crystallography ID GLUTATHIONE-S-TRANSFERASE; PANCREATIC TRYPSIN-INHIBITOR; PROTEIN CRYSTAL-GROWTH; GENE ACTIVATOR PROTEIN; URACIL DNA GLYCOSYLASE; X-RAY REFINEMENT; CALCIUM-INDEPENDENT SUBTILISIN; NUCLEOSIDE DIPHOSPHATE KINASE; URIDINE-VANADATE COMPLEX; SUBSTRATE-BINDING SITE AB In the late 1970s, macromolecular crystallography at NIST began with collaboration between NIST and NIH to establish a single-crystal neutron diffractometer. This instrument was constructed and employed to solve a number of crystal structures: bovine ribonuclease A, bovine-ribonuclease-uridine vanadate complex, and porcine insulin. In the mid 1980s a Biomolecular Structure Group was created establishing NIST capabilities in biomolecular singe-crystal x-ray diffraction. The group worked on a variety of structural problems until joining the NIST/UMBI Center for Advanced Research in Biotechnology ( CARB) in 1987. Crystallographic studies at CARB were then focused on protein engineering efforts that included among others chymosin, subtilisin BPN', interleukin 1beta and glutathione S-transferase. Recently, the structural biology efforts have centered on enzymes in the chorismate metabolic pathways involved in amino acid biosynthesis and in structural genomics that involves determining the structures of hypothetical proteins to aid in assigning function. In addition to crystallographic studies, structural biology database activities began with the formal establishment of the Biological Macromolecule Crystallization Database in 1989. Later, in 1997, NIST in partnership with Rutgers and UCSD formed the Research Collaboratory for Structural Bioinformatics that successfully acquired the Protein Data Bank. The NIST efforts in these activities have focused on data uniformity, establishing and maintaining the physical archive, and working with the NMR community. C1 Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NIST, Ctr Adv Res Biotechnol, Div Biotechnol, Chem Sci & Technol Lab, Rockville, MD 20850 USA. RP Gilliland, GL (reprint author), Univ Maryland, Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. NR 110 TC 0 Z9 0 U1 0 U2 10 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 2001 VL 106 IS 6 BP 1155 EP 1173 PG 19 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 527WM UT WOS:000174211000018 PM 27500071 ER PT J AU Grey, IE Roth, RS Mumme, WG Planes, J Bendersky, L Li, C Chenavas, J AF Grey, IE Roth, RS Mumme, WG Planes, J Bendersky, L Li, C Chenavas, J TI Characterization of new 5M and 7M polytypes of niobia-doped Ca2Ta2O7 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID POWDER DIFFRACTION; RIETVELD ANALYSIS; X-RAY; PARAMETERS; CERAMICS; SYSTEM AB Two new calcium tantalate polytypes have been prepared in the system Ca2Ta2O7- Ca2Nb2O7. Their structures have been determined and refined using single-crystal X-ray diffraction data and powder neutron diffraction data, and their dielectric properties have been measured in the 100 kHz to 10 GHz frequency range. The 7M polytype of pure Ca2Ta2O7 has monoclinic symmetry with a = 12.726(1), b = 7.380(1), c = 42.538(1) Angstrom, beta = 95.77(1), Z = 28, space group C2. The 7M Ca2Ta1.9Nb0.1O7 is isostructural, with a = 12.7170(6), b = 7.3728(3), c = 42.464(2) Angstrom, beta = 95.755(5)degrees. The 5M Ca-2 Ta1.8Nb0.2O7 is monoclinic with a = 12.7528(4), b = 7.3492(2), c = 30.2442(8) Angstrom, beta = 94.245(2), Z = 20, space group C2. The two polytypes have in common a closest-packing of (001) metal atom layers that alternately have the composition Ca3Ta and Ta3Ca. The polytypes have mixed hexagonal-cubic stacking sequences of the metal atom layers: 7M = hccccchccccccch..., 5M = hccchccccch.... The cubic-stacked blocks have weberite-type structures in both polytypes, in which hexagonal tungsten bronze type layers of corner-connected octahedra are interconnected via corner linking to isolated TaO6 octahedra in the Ca3Ta layers to give a [Ta2O7](4-) framework within which the eight-coordinated calcium atoms are distributed. The polytypes display a broad resonance at about 8 GHz, with relative permittivities of similar to 25 and with Q values of about 200. (C) 2001 Academic Press. C1 CSIRO, Clayton, Vic 3169, Australia. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. CEA, DSM, DRFMC, F-38054 Grenoble, France. CNRS, Cristallog Lab, F-38042 Grenoble, France. RP Grey, IE (reprint author), CSIRO, Box 312, Clayton, Vic 3169, Australia. RI Planes, Jerome/C-6879-2011 OI Planes, Jerome/0000-0003-2752-0762 NR 15 TC 6 Z9 6 U1 0 U2 18 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD NOV 1 PY 2001 VL 161 IS 2 BP 274 EP 287 DI 10.1006/jssc.2001.9308 PG 14 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 497QF UT WOS:000172466400013 ER PT J AU Obmolova, G Teplyakov, A Bonander, N Eisenstein, E Howard, AJ Gilliland, GL AF Obmolova, G Teplyakov, A Bonander, N Eisenstein, E Howard, AJ Gilliland, GL TI Crystal structure of dephospho-coenzyme A kinase from Haemophilus influenzae SO JOURNAL OF STRUCTURAL BIOLOGY LA English DT Article DE CoA synthesis; Haemophilus influenzae; kinase; nucleotide binding fold ID ADENYLATE KINASE; ESCHERICHIA-COLI; THYMIDINE KINASE; COMPLEX; FOLD; SPECIFICITY; RESOLUTION; MECHANISM; SEQUENCES; REVEAL AB Dephospho-coenzyme A kinase catalyzes the final step in CoA biosynthesis, the phosphorylation of the T-hydroxyl group of ribose using ATP as a phosphate donor. The protein from Haemophilus influenzae was cloned and expressed, and its crystal structure was determined at 2.0-Angstrom resolution in complex with ATP. The protein molecule consists of three domains: the canonical nucleotide-binding domain with a five-stranded parallel beta-sheet, the substrate-binding a-helical domain, and the lid domain formed by a pair of alpha-helices. The overall topology of the protein resembles the structures of nucleotide kinases. ATP binds in the beta-loop in a manner observed in other kinases. The CoA-binding site is located at the interface of all three domains. The double-pocket structure of the substrate-binding site is unusual for nucleotide kinases. Amino acid residues implicated in substrate binding and catalysis have been identified. The structure analysis suggests large domain movements during the catalytic cycle. (C) 2001 Elsevier Science (USA). C1 Univ Maryland, Inst Biotechnol, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Natl Inst Stand & Technol, Rockville, MD 20850 USA. IIT, Chem & Phys Sci Dept, Ctr Synchrotron Radiat Res & Instrumentat, Chicago, IL 60616 USA. RP Obmolova, G (reprint author), Univ Maryland, Inst Biotechnol, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. RI ID, IMCACAT/D-5867-2014; OI Teplyakov, Alexey/0000-0003-0296-0016 FU NIGMS NIH HHS [P01-GM57890] NR 27 TC 24 Z9 25 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1047-8477 J9 J STRUCT BIOL JI J. Struct. Biol. PD NOV PY 2001 VL 136 IS 2 BP 119 EP 125 DI 10.1006/jsbi.2001.4428 PG 7 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 531UU UT WOS:000174436300005 PM 11886213 ER PT J AU Lee, CS Lawn, BR Kim, DK AF Lee, CS Lawn, BR Kim, DK TI Effect of tangential loading on critical conditions for radial cracking in brittle coatings SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID FRACTURE; INTERLAYER; CERAMICS; MODULUS; FORCE AB Results of Hertzian contact tests investigating the effects of superposed tangential loads on the critical conditions for radial cracking at the undersurfaces of brittle coatings on compliant substrates are reported. It is demonstrated that these effects are secondary, so that conventional normal indentation remains an appropriate test procedure for characterizing this highly deleterious mode of coating fracture under a wide range of complex loading conditions. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Korea Adv Inst Sci & Technol, Dept Mat Sci & Engn, Taejon 305701, South Korea. RP Lee, CS (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Kim, Do Kyung/C-2039-2011 OI Kim, Do Kyung/0000-0001-9092-9427 NR 15 TC 11 Z9 11 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD NOV PY 2001 VL 84 IS 11 BP 2719 EP 2721 PG 3 WC Materials Science, Ceramics SC Materials Science GA 491YE UT WOS:000172137000046 ER PT J AU Chen, R Yalcin, T Wallace, WE Guttman, CM Li, L AF Chen, R Yalcin, T Wallace, WE Guttman, CM Li, L TI Laser desorption ionization and MALDI time-of-flight mass spectrometry for low molecular mass polyethylene analysis SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID FIELD DESORPTION; SYNTHETIC-POLYMERS; IDENTIFICATION; ADDITIVES AB Polyethylene's inert nature and difficulty to dissolve in conventional solvents at room temperature present special problems for sample preparation and ionization in mass spectrometric analysis. We present a study of ionization behavior of several polyethylene samples with molecular masses up to 4000 Da in laser desorption ionization (LDI) time-of-flight mass spectrometers equipped with a 337 nm laser beam. We demonstrate unequivocally that silver or copper ion attachment to saturated polyethylene can occur in the gas phase during the UV LDI process. In LDI spectra of polyethylene with molecular masses above similar to 1000 Da, low mass ions corresponding to metal-alkene structures are observed in addition to the principal distribution. By interrogating a well-characterized polyethylene sample and a long chain alkane, C94H190, these low mass ions are determined to be the fragmentation products of the intact metal-polyethylene adduct ions. It is further illustrated that fragmentation can be reduced by adding matrix molecules to the sample preparation. (C) 2001 American Society for Mass Spectrometry. C1 Univ Alberta, Dept Chem, Edmonton, AB T6G 2G2, Canada. NIST, Div Polymers, Gaithersburg, MD 20899 USA. Univ Alberta, Dept Chem, Edmonton, AB, Canada. RP Li, L (reprint author), Univ Alberta, Dept Chem, W3-39 Chem Bldg, Edmonton, AB T6G 2G2, Canada. RI Li, Liang/D-1822-2011 NR 27 TC 41 Z9 41 U1 1 U2 15 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD NOV PY 2001 VL 12 IS 11 BP 1186 EP 1192 DI 10.1016/S1044-0305(01)00308-7 PG 7 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 490XN UT WOS:000172079100007 PM 11720394 ER PT J AU Wheelon, AD AF Wheelon, AD TI Skewed distribution of irradiance predicted by the second-order Rytov approximation SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID NUMERICAL-SIMULATION; SCINTILLATION AB The first-order Rytov approximation predicts that the probability-density function for intensity fluctuations in a random medium should be a log normal distribution. Here the corrections to this prediction that arise from the second term in the Rytov series are explored. The primary effect is to skew the distribution so as to favor values that are less than the average. This effect is controlled by the Rytov variance beta (2)(0) alone, and the predicted distribution contains no adjustable parameters. The theoretical result is compared with numerical simulations for weak scattering of plane and spherical waves. The agreement is quite good unless the intensity fluctuations are very large or very small relative to the mean irradiance. In those ranges, the predictions require additional terms in the Rytov expansion. (C) 2001 Optical Society of America. C1 NOAA, Environm Res Lab, Environm Technol Lab, Boulder, CO 80303 USA. RP Wheelon, AD (reprint author), NOAA, Environm Res Lab, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. NR 19 TC 8 Z9 8 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD NOV PY 2001 VL 18 IS 11 BP 2789 EP 2798 DI 10.1364/JOSAA.18.002789 PG 10 WC Optics SC Optics GA 486UY UT WOS:000171836400015 PM 11688869 ER PT J AU Knappe, S Wynands, R Kitching, J Robinson, HG Hollberg, L AF Knappe, S Wynands, R Kitching, J Robinson, HG Hollberg, L TI Characterization of coherent population-trapping resonances as atomic frequency references SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID MICROWAVE EMISSION; RAMAN TRANSITION; RAMSEY FRINGES; CESIUM; SPECTROSCOPY; LINES; BEAM; INVERSION; FOUNTAIN; STANDARD AB A low-cost, potentially compact and robust microwave frequency reference can be constructed by use of vertical-cavity surface-emitting lasers and coherent population-trapping resonances in Cs vapor cells. Fractional frequency instabilities of 2 x 10(-11)/root tau /s have been achieved with a minimum of 7 x 10(-13) at tau = 1000s. The performance of this device as a function of external parameters such as light intensity, optical detuning, and cell temperature is discussed. The dependence of the dark-line resonance signal on these parameters can be understood largely by means of a simple, three-level model. The short-term stability depends critically on the optical detuning, whereas the long-term stability is limited currently by line shifts due to drifts in cell temperature. C1 Univ Bonn, Inst Angew Phys, D-53115 Bonn, Germany. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Knappe, S (reprint author), Univ Bonn, Inst Angew Phys, Wegelerstr 8, D-53115 Bonn, Germany. NR 32 TC 96 Z9 100 U1 1 U2 9 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD NOV PY 2001 VL 18 IS 11 BP 1545 EP 1553 DI 10.1364/JOSAB.18.001545 PG 9 WC Optics SC Optics GA 491CE UT WOS:000172089800001 ER PT J AU Kitching, J Robinson, HG Hollberg, L Knappe, S Wynands, R AF Kitching, J Robinson, HG Hollberg, L Knappe, S Wynands, R TI Optical-pumping noise in laser-pumped, all-optical microwave frequency references SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID AMPLITUDE NOISE; PHASE NOISE; LIGHT SHIFT; POPULATION; SPECTROSCOPY; FLUCTUATIONS; RESONANCES; VAPOR; CONVERSION; CESIUM AB We demonstrate that optical pumping plays a significant role in determining the noise in certain types of laser-pumped vapor-cell microwave frequency standards by changing the way in which the laser's FM noise is converted to AM noise by the optical-absorption profile. When this FM-AM conversion is the dominant noise source, the noise spectrum of the transmitted intensity can be dramatically altered by the optical-pumping process. FM noise at Fourier frequencies larger than the optical-pumping time is converted to AM noise differently from noise at lower Fourier frequencies. This effect can modify the optimum design of vapor-cell frequency references and adds an additional FM-AM-related noise source that cannot be eliminated with laser tuning. (C) 2001 Optical Society of America. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. Univ Bonn, Inst Angew Phys, D-53115 Bonn, Germany. RP Kitching, J (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, MS 847-10,325 Broadway, Boulder, CO 80303 USA. NR 25 TC 39 Z9 41 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 NOV PY 2001 VL 18 IS 11 BP 1676 EP 1683 DI 10.1364/JOSAB.18.001676 PG 8 WC Optics SC Optics GA 491CE UT WOS:000172089800017 ER PT J AU Soles, CL Lin, EK Lenhart, JL Jones, RL Wu, WL Goldfarb, DL Angelopoulos, M AF Soles, CL Lin, EK Lenhart, JL Jones, RL Wu, WL Goldfarb, DL Angelopoulos, M TI Thin film confinement effects on the thermal properties of model photoresist polymers SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 45th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication CY MAY 29-JUN 01, 2001 CL WASHINGTON, D.C. SP Amer Vacuum Soc, IEEE Electron Device Soc, Opt Soc Amer ID GLASS-TRANSITION TEMPERATURE; INTERFACE; PROBE; POLYSTYRENE; DYNAMICS; MOBILITY; THICKNESS; LIQUIDS; MOTIONS; SIZE AB The demand to print increasingly smaller microelectronic device features means that the thickness of the polymer films used in the lithographic processes must decrease. The thickness of these films is rapidly approaching the unperturbed dimensions of the polymer, length scales at which confinement deviations and dewetting are a significant concern. We combine specular x-ray reflectivity (SXR) and incoherent neutron scattering (INS) to probe the thermal stability and dynamical effects of thin film confinement in poly(hydroxy styrene) (PHS), a polymer used in a majority of the 248 nm deep UV photoresists. PHS forms stable thin films (down to 5 nm) that do not dewet over a wide temperature range on Si surfaces ranging from hydrophilic to hydrophobic. The surface energy has a profound influence on the magnitude of the thin film expansion coefficient, especially above the glass transition, in films as thick as 100 nm. Confinement also appears to suppress the mean-square atomic displacements and the level of anharmonicity in the dynamics, primarily above the bulk glass transition. (C) 2001 American Vacuum Society. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA. RP Soles, CL (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. EM csoles@nist.gov NR 25 TC 34 Z9 34 U1 1 U2 6 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 2001 VL 19 IS 6 BP 2690 EP 2693 DI 10.1116/1.1415502 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 509PY UT WOS:000173159900121 ER PT J AU Goldfarb, DL Angelopoulos, M Lin, EK Jones, RL Soles, CL Lenhart, JL Wu, WL AF Goldfarb, DL Angelopoulos, M Lin, EK Jones, RL Soles, CL Lenhart, JL Wu, WL TI Confinement effects on the spatial extent of the reaction front in ultrathin chemically amplified photoresists SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 45th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication CY MAY 29-JUN 01, 2001 CL WASHINGTON, D.C. SP Amer Vacuum Soc, IEEE Electron Device Soc, Opt Soc Amer ID DEEP-ULTRAVIOLET RESISTS; GLASS-TRANSITION TEMPERATURE; ACID DIFFUSION; IMAGING TECHNIQUE; POLYMER-FILMS; RESOLUTION; MOBILITY; SOLVENT; THIN AB Sub-100 nm lithography poses strict requirements on photoresist material properties and processing conditions to achieve necessary critical dimension control of patterned structures. As resist thickness and feature linewidth decrease, fundamental materials properties of the confined resist polymer can deviate from bulk values and impact important processing parameters such as the postexposure bake (PEB) temperature. The effects of these confinement-induced deviations on image or linewidth spread have not been explored. In this work, we characterize the resist thickness dependence of the spatial extent of the reaction-diffusion process in a chemically amplified photoresist system under varying processing conditions. Bilayer samples are prepared with a lower layer of a protected polymer (p-tert-butoxycarboxystyrene) and a top layer of a de-protected polymer [poly (4-hydroxystyrene)] loaded with a photoacid generator. After flood exposure, PEB, and development, changes in the thickness of the protected polymer provide a measure of the spatial extent of the reaction front between the polymer layers. The velocity of the reaction front is significantly reduced with decreasing thickness of the protected polymer layer under identical processing conditions. (C) 2001 American Vacuum Society. C1 IBM Corp, TJ Watson Res Ctr, Yorktown Hts, NY 10598 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP IBM Corp, TJ Watson Res Ctr, Yorktown Hts, NY 10598 USA. EM goldfarb@us.ibm.com NR 28 TC 45 Z9 45 U1 0 U2 4 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 2001 VL 19 IS 6 BP 2699 EP 2704 DI 10.1116/1.1421559 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 509PY UT WOS:000173159900123 ER PT J AU Brown, AL Busby, MS Mier, KL AF Brown, AL Busby, MS Mier, KL TI Walleye pollock Theragra chalcogramma during transformation from the larval to juvenile stage: otolith and osteological development SO MARINE BIOLOGY LA English DT Article ID FLOUNDER PSEUDOPLEURONECTES-AMERICANUS; WESTERN GULF; PAIRED FINS; MICROSTRUCTURE; GROWTH; METAMORPHOSIS; VALIDATION; AGE; MICROCHEMISTRY; INCREMENTS AB Walleye pollock [Theragra chalcogramma (Pallas, 1814)] were collected from the Gulf of Alaska from 1991 to 1998 to examine the relationship between otolith and osteological development during transformation from the larval to juvenile life stage. Five stages of otolith development were determined for walleye pollock in conjunction with landmarks in osteological development during juvenile transformation. The first stage of otolith development (12-19 mm SL) is identified by the first accessory growth center (AGC) forming on sagittal otoliths. At this stage, the notochord is undergoing flexion as the teeth, jaws, branchiostegal rays, neural spines, and abdominal vertebral centra are ossifying. The second and third stages of otolith development (19-21 and 21-24 mm SL) are defined by the formation of the anterior, posterior, and dorsal AGCs on the otolith. This occurs during postflexion in conjunction with ossification of the principal caudal-fin rays, haemal spines, and caudal vertebral centra. The fourth stage of otolith development (24-37 mm SL) is defined by the AGCs on the ventral edge of the otolith. By this stage of development, the pelvic-, pectoral-, dorsal-, and anal-fin ray elements have started ossification and the fish has entered the transformation stage. The fifth stage of otolith development (36-48 mm SL) is identified by a completely formed sagittal otolith, which has AGCs that have grown together so that the otolith shape resembles an adult otolith, the ossification of all vertebrae and fin rays is complete, and the fish is a juvenile. By estimating what length a fish was, based solely on otolith development, would prove helpful for those who wish to reconstruct length frequencies of walleye pollock from otoliths of fish that have been damaged due to gear and/or poor handling during the preservation process. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Brown, AL (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. EM Annette.Brown@noaa.gov NR 23 TC 30 Z9 30 U1 1 U2 7 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD NOV PY 2001 VL 139 IS 5 BP 845 EP 851 PG 7 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 503HR UT WOS:000172793500005 ER PT J AU Bentz, DP Hansen, KK Madsen, HD Vallee, F Griesel, EJ AF Bentz, DP Hansen, KK Madsen, HD Vallee, F Griesel, EJ TI Drying/hydration in cement pastes during curing SO MATERIALS AND STRUCTURES LA English DT Article ID CONCRETE AB As concrete cures in the field, there is a constant competition for the mixing water between evaporation and hydration processes. Understanding the mechanisms of water movement in the drying/hydrating cement paste is critical for designing curing systems and specialized rendering materials, as well as for selecting repair materials and methodologies. In this work, X-ray absorption measurements indicate that fresh cement paste dries uniformly throughout its thickness, as opposed to exhibiting the sharp drying front observed for most porous materials. Furthermore, in layered composite cement paste specimens, water always flows from the coarser-pore layer to the finer one, both when coarser pores are produced by using an increased water-to-cement ratio (w/c) and when they are present due to using a cement with a coarser particle size distribution at a constant w/c. Conversely, no clear differential water movement is observed between layers of cement paste and mortar of the same nominal w/c. Based on the results of these experiments, drying has been introduced into the NIST CEMHYD3D cement hydration and microstructure development model, by emptying the largest water-filled pores present at any depth in the model specimen at a user-specified (drying) rate. With this addition, the CEMHYD3D model produces results in good agreement with experimental observations of both the drying profiles and the hydration kinetics of thin cement paste specimens. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Tech Univ Denmark, DK-2800 Lyngby, Denmark. Ctr Sci & Tech Batiment, Marne La Vallee, France. Univ Cape Town, ZA-7700 Rondebosch, South Africa. RP Bentz, DP (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, 100 Bur Dr Stop 8621, Gaithersburg, MD 20899 USA. NR 21 TC 21 Z9 21 U1 1 U2 5 PU R I L E M PUBLICATIONS PI CACHAN PA 61 AVE PRESIDENT WILSON, 94235 CACHAN, FRANCE SN 1359-5997 J9 MATER STRUCT JI Mater. Struct. PD NOV PY 2001 VL 34 IS 243 BP 557 EP 565 DI 10.1007/BF02482182 PG 9 WC Construction & Building Technology; Engineering, Civil; Materials Science, Multidisciplinary SC Construction & Building Technology; Engineering; Materials Science GA 494ZL UT WOS:000172315700004 ER PT J AU Koning, R Dixson, R Fu, J Vorburger, TV AF Koning, R Dixson, R Fu, J Vorburger, TV TI The role of periodic interferometer errors in the calibration of capacitance displacement sensors for nanometrology applications SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE capacitance displacement sensor; interferometry; error analysis; calibration; nanometrology ID NONLINEARITY AB Although the role of the periodic errors of optical heterodyne interferometers; in displacement measurements is fairly well understood, their influence on the calibration of other types of displacement sensor does not seem to be studied as extensively. We have performed a careful analysis of the role of these errors on the calibration of a capacitance displacement sensor, which is integrated into a linear piezoelectric transducer for nanometrology applications over displacement ranges in the sub-micrometre range. Assuming a linear dependence of the output voltage of the capacitance displacement sensor on the displacement it was found analytically that periodic interferometer errors lead to a decaying oscillation of the sensor sensitivity as the displacement range used in the calibration increases. For use of a double path interferometer with a polarization mixing amplitude of 0.5 nm and a polarization mixing wavelength of 79 nm, deviations of sensor sensitivity of 0.3% for a range of 0.2 mum and 0.029% for a range of 1 mum were estimated. The pronounced oscillations of the sensor's sensitivity over very small displacement ranges as predicted by the theoretical description were verified experimentally. C1 NIST, Precis Engn Div, Gaithersburg, MD 20899 USA. RP NIST, Precis Engn Div, Gaithersburg, MD 20899 USA. EM rainer.koning@ptb.de; ronald.dixson@nist.gov; theodore.vorburger@nist.gov NR 14 TC 4 Z9 4 U1 0 U2 0 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 NOV PY 2001 VL 12 IS 11 BP 2002 EP 2008 DI 10.1088/0957-0233/12/11/333 PG 7 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 498QW UT WOS:000172522800034 ER PT J AU Vogel, EM Edelstein, MD Suehle, JS AF Vogel, EM Edelstein, MD Suehle, JS TI Reliability of ultra-thin silicon dioxide under substrate hot-electron, substrate hot-hole and tunneling stress SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT 12th Biennial Conference on Insulating Films on Semiconductors CY JUN 20-23, 2001 CL UDINE, ITALY SP ST Microelectr, IEEE Electron Devices Soc, NEAR EST Consortium, CISM, Reg Friuli Venezia Giulia, Undine, Fdn CRUP DE metal-oxide-semiconductor (MOS); gate dielectric; reliability; silicon dioxide; hot-electron; hot-hole; tunneling ID DEPENDENT DIELECTRIC-BREAKDOWN; FIELD-EFFECT TRANSISTORS; GATE OXIDE BREAKDOWN; INTERFACE DEGRADATION; DEFECT GENERATION; TRAP GENERATION; INJECTION; VOLTAGE; FILMS; MODEL AB Substrate hot-electron and substrate hot-hole injection experiments are used to provide insight into defect generation and breakdown of ultra-thin silicon dioxide under constant voltage tunneling stress. Results from substrate hot-electron injection confirm that energetic electrons are responsible for degradation and breakdown of ultra-thin silicon dioxide under tunneling stress conditions. Substrate hot-hole injection experiments suggest that mechanisms other than trapping of hot holes may be responsible for the break-down of ultra-thin silicon dioxide. (C) 2001 Elsevier Science BY All rights reserved. C1 NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Vogel, EM (reprint author), NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. EM eric.vogel@nist.gov RI Vogel, Eric/A-7731-2008 OI Vogel, Eric/0000-0002-6110-1361 NR 30 TC 6 Z9 6 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9317 J9 MICROELECTRON ENG JI Microelectron. Eng. PD NOV PY 2001 VL 59 IS 1-4 BP 73 EP 83 DI 10.1016/S0167-9317(01)00650-5 PG 11 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA 493JD UT WOS:000172218100011 ER PT J AU Davis, MW Olla, BL AF Davis, MW Olla, BL TI Stress and delayed mortality induced in Pacific halibut by exposure to hooking, net towing, elevated seawater temperature and air: Implications for management of bycatch SO NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT LA English DT Article ID OTTER-TRAWL; SABLEFISH; FISHERIES; LONGLINE; SURVIVAL AB The extent of stress and eventual mortality in Pacific halibut Hippoglossus stenolepis that resulted from simulated capture by hooking or towing in a net, followed by abrupt exposure to warmer seawater temperature and air, were determined under laboratory conditions. Abrupt exposure to 16degreesC seawater and air after either method of capture increased capture-induced stress, with accompanying mortality of 33% for hooked fish and 78% for fish towed in a net. Moreover, these deaths occurred as long as 30 d after experimental treatment, Suggesting that delayed mortality should be considered in any study of Pacific halibut bycatch mortality. Stress induced by hooking or towing in a net followed by air exposure was reflected in cessation of negative phototaxis and feeding, both of which were resumed after 5 d with no mortality occurring. The results of this study clearly show that seasonal increases in temperature associated with thermoclines and deck conditions have the potential for markedly increasing the mortality of Pacific halibut that might otherwise survive capture and release in colder seasons. Strategies for effective management of Pacific halibut bycatch need to include consideration of seasonal temperature increases and how this factor might increase mortality. C1 Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. RP Davis, MW (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. NR 23 TC 48 Z9 48 U1 0 U2 4 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0275-5947 J9 N AM J FISH MANAGE JI North Am. J. Fish Manage. PD NOV PY 2001 VL 21 IS 4 BP 725 EP 732 DI 10.1577/1548-8675(2001)021<0725:SADMII>2.0.CO;2 PG 8 WC Fisheries SC Fisheries GA 529FL UT WOS:000174289300003 ER PT J AU Cole, RV Helser, TE AF Cole, RV Helser, TE TI Effect of three bycatch reduction devices on diamondback terrapin Malaclemys terrapin capture and blue crab Callinectes sapidus harvest in Delaware bay SO NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT LA English DT Article ID POTS AB In recent years, reduction of the taking of nontarget species in fisheries worldwide has received considerable attention. Bycatch mortality in pot fisheries has led to severe declines in local populations of the diamondback terrapin Malaclemys terrapin along the U.S. East Coast. We conducted a 4-year study between 1997 and 2000 to investigate the impact of four bycatch reduction devices (BRDs), wire rectangular devices fitted into the entrance of crab traps, on diamondback terrapin bycatch mortality as well as its effect on the harvest of blue crabs Callinectes sapidus in the Delaware River estuary. A total of 52 sets consisting of five replicate blue crab pots for each BRD treatment (5.0 X 10.0, 5.0 X 12.0, 4.5 X 12.0, and 3.8 X 12.0 cm) and controls were deployed at random in 10 tidal tributaries and inland bays within the Delaware estuary. During this study 372 diamondback terrapins, and 3,522 legal-size blue crabs were caught. The 5-cm X 12-cm BRD was the only treatment for which the reduction in overall diamondback terrapin catches (-12%) was not statistically significant. In crab pots fitted with the 5-cm X 10-cm BRD, we observed a statistically significant (P < 0.01) reduction in terrapin catches (-59%) versus control pots, with no statistical difference in blue crab catches. Only a nominal loss (-12%) of legal-size blue crab catches was observed in pots fitted with the 4.5-cm X 12.0-cm BRD, whereas the reduction in diamondback terrapin captures (38% male and 96% female) was significant (P < 0.01). No diamondback terrapins were captured in the smallest BRD (3.8 X 12.0 cm), but the losses of legal-size blue crab catches were substantial (26%). We therefore recommend the use of the 4.5-cm X 12.0-cm BRD with recreational crab pots as a conservation measure because this would effectively protect all subadult and reproductive female diamondback terrapins with minimal loss of legal blue crabs. We also stress the importance of using the BRDs in concert with other conservation measures, such as efforts directed at monitoring the effects of BRD implementation on bycatch mortality and preservation of nesting. C1 Delaware Div Fish & Wildlife, Little Creek, DE 19961 USA. RP Helser, TE (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98122 USA. NR 22 TC 13 Z9 13 U1 0 U2 7 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0275-5947 J9 N AM J FISH MANAGE JI North Am. J. Fish Manage. PD NOV PY 2001 VL 21 IS 4 BP 825 EP 833 DI 10.1577/1548-8675(2001)021<0825:EOTBRD>2.0.CO;2 PG 9 WC Fisheries SC Fisheries GA 529FL UT WOS:000174289300013 ER PT J AU Pothoven, SA Nalepa, TF Schneeberger, PJ Brandt, SB AF Pothoven, SA Nalepa, TF Schneeberger, PJ Brandt, SB TI Changes in diet and body condition of lake whitefish in southern Lake Michigan associated with changes in benthos SO NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT LA English DT Article ID COREGONUS-CLUPEAFORMIS; ZEBRA MUSSEL; DREISSENA-POLYMORPHA; GREAT-LAKES; ONTARIO; GROWTH; SIZE; MACROINVERTEBRATES; POPULATIONS; BIOMASS AB We evaluated the long-term trends of the benthic macroinvertebrate community (1980-1999) and biological attributes of lake whitefish Coregonus clupraformis (1985-1999) in southeastern Lake Michigan. We also determined what food types were important to lake whitefish in an area where the amphipod Diporeia had not yet declined in 1998 and how the diet of lake whitefish changed as Diporeia declined during 1999-2000. Zebra mussels Dreissena polymorpha invaded the study area in 1992; Diporeia began to decline in 1993 and was nearly absent by 1999. The body condition of lake whitefish decreased after 1993 and remained low thereafter. The length at age and weight at age of lake whitefish was lower in 1992-1999 than in 1985-1991. After declines of Diporeia off the city of Muskegon, Michigan, between 1998 and 1999-2000, the proportion of Diporeia in the diet by weight fell from 70% to 25% and the percent occurrence decreased from 81% to 45%. In contrast, the proportion of take whitefish that ate other prey, such as Mysis relicta (an opossum shrimp), ostracods, oligochaetes, and zooplankton, increased in the same period. At sites south of Muskegon, where the density of Diporeia has been low since 1998, chironomids, zebra mussels, and fingernail clams (Shacriidae family) were the most important diet items of lake whitefish. Decreases in body condition and growth are associated with the loss of the high-energy prey resource Diporeia, the consumption of prey with lower energy content, such as zebra mussels, and possible density-dependence. Commercial harvests of lake whitefish will probably decrease because of low body condition and growth. Future management may require changes in harvest quotas, size restrictions, and depth restrictions as zebra mussel-related impacts spread northward in Lake Michigan. C1 Univ Michigan, Great Lakes Environm Res Lab, Lake Michigan Field Stn, Cooperat Inst Limnol & Ecosyst Res, Muskegon, MI 49441 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Michigan Dept Nat Resources, Marquette Fisheries Res Stn, Marquette, MI 49855 USA. RP Pothoven, SA (reprint author), Univ Michigan, Great Lakes Environm Res Lab, Lake Michigan Field Stn, Cooperat Inst Limnol & Ecosyst Res, 1431 Beach St, Muskegon, MI 49441 USA. RI Biguzzi, Felipe/E-4724-2015; OI Pothoven, Steven/0000-0002-7992-5422 NR 30 TC 116 Z9 117 U1 2 U2 20 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0275-5947 J9 N AM J FISH MANAGE JI North Am. J. Fish Manage. PD NOV PY 2001 VL 21 IS 4 BP 876 EP 883 DI 10.1577/1548-8675(2001)021<0876:CIDABC>2.0.CO;2 PG 8 WC Fisheries SC Fisheries GA 529FL UT WOS:000174289300017 ER PT J AU Buchter, SC Fan, TY Liberman, V Zayhowski, JJ Rothschild, M Mason, EJ Cassanho, A Jenssen, HP Burnett, JH AF Buchter, SC Fan, TY Liberman, V Zayhowski, JJ Rothschild, M Mason, EJ Cassanho, A Jenssen, HP Burnett, JH TI Periodically poled BaMgF4 for ultraviolet frequency generation SO OPTICS LETTERS LA English DT Article ID BARIUM FLUORIDE AB Ferroelectric domain inversion has been demonstrated in BaMgF4. Transparency has been measured to < 140 nm, and no change in transmission was measured under 157-nm irradiation for >1.1 X 10(9) shots at 2 mJ/cm(2) per pulse. First-order quasi-phase-matched generation of 157 nm is predicted by use of grating periods as long as 1.5 mum. This material should permit shorter-wavelength chi ((2)) frequency-mixing processes than with any other crystalline material. (C) 2001 Optical Society of America. C1 MIT, Lincoln Lab, Lexington, MA 02420 USA. MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA. AC Mat, Winter Pk, FL 32792 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Buchter, SC (reprint author), MIT, Lincoln Lab, MS-L-134,244 Wood St, Lexington, MA 02420 USA. NR 11 TC 52 Z9 53 U1 0 U2 9 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD NOV 1 PY 2001 VL 26 IS 21 BP 1693 EP 1695 DI 10.1364/OL.26.001693 PG 3 WC Optics SC Optics GA 492HH UT WOS:000172162000019 PM 18049702 ER PT J AU Lu, CJ Senz, S Hesse, D AF Lu, CJ Senz, S Hesse, D TI The influence of yttria-stabilized zirconia surface pits on the initial stage of reactive La2Zr2O7 formation from La2O3 vapours and yttria-stabilized zirconia (001) substrates SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID SOLID-STATE REACTIONS; OXIDE FUEL-CELLS; LANTHANUM MANGANITE; REACTION-MECHANISM; REACTION FRONTS; INTERFACE; ZRO2; ELECTROLYTE; MGO(001); KINETICS AB The initial stage of La2Zr2O7 (LZO) formation by an interfacial solid state reaction between yttria-stabilised zirconia (YSZ) and La2O3 is experimentally investigated. LZO islands are formed on YSZ(001) single-crystal surfaces exposed to La2O3 vapours when a high density of pits are present on the YSZ surface. Compared with the previously studied formation of almost epitaxial La2Zr2O7 islands on a perfectly plane YSZ surface, characteristic differences and new features are found, which are explained by the influence of the pit rims. Whereas islands growing far away from a pit have a regular structure and consist of four [110]-tilted domains, islands growing near a pit involve a central hole and consist of two to four [100]-tilted stripe domains in addition to the four regular [110]-tilted domains. The new stripe domains contain two orthogonal sets of misfit dislocations: one of a Burgers vector with a component perpendicular to the interface plane, and the other of an in-plane Burgers vector. These new features are explained in terms of the preferred nucleation of LZO islands near the pit and their specific growth kinetics under the influence of the pit rim, where the stresses arising in the growing islands are partially relaxed by the deformation of the pit rim. C1 Max Planck Inst Microstruct Phys, D-06120 Halle Saale, Germany. RP Lu, CJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 24 TC 11 Z9 11 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD NOV PY 2001 VL 81 IS 11 BP 2705 EP 2723 PG 19 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 483HZ UT WOS:000171631100012 ER PT J AU Rich, DR Fan, S Gentile, TR Hussey, D Jones, GL Neff, B Snow, WM Thompson, AK AF Rich, DR Fan, S Gentile, TR Hussey, D Jones, GL Neff, B Snow, WM Thompson, AK TI Polarized He-3 neutron spin filter development and application at Indiana University and NIST SO PHYSICA B LA English DT Article DE neutron polarization; polarized He-3 ID LA1-XCAXMNO3; NUCLEI; LASER; GAS AB Neutron spin filters based on polarized He-3 promise to significantly expand the range of applications of polarized neutron scattering, particularly for experiments with divergent beams. At NIST and at Indiana University, we are pursuing both methods of polarizing He-3 by optical pumping: the metastability exchange method, and spin exchange with optically pumped Rb. The status of the respective apparatus and application to small angle neutron scattering (SANS) at the National Institute of Standards and Technology (NIST) and neutron reflectometry at the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory are discussed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Indiana Univ, Bloomington, IN 47405 USA. NIST, Gaithersburg, MD 20899 USA. Hamilton Coll, Clinton, NY 13323 USA. RP Rich, DR (reprint author), Wabash Coll, Dept Phys, Crawfordsville, IN 47933 USA. NR 20 TC 5 Z9 5 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD NOV PY 2001 VL 305 IS 3-4 BP 203 EP 207 DI 10.1016/S0921-4526(01)00617-2 PG 5 WC Physics, Condensed Matter SC Physics GA 489TA UT WOS:000172006700002 ER PT J AU Davydov, AV Boettinger, WJ Kattner, UR Anderson, TJ AF Davydov, AV Boettinger, WJ Kattner, UR Anderson, TJ TI Thermodynamic assessment of the gallium-nitrogen system SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT 4th International Conference on Nitride Semiconductors (ICNS-4) CY JUL 16-20, 2001 CL DENVER, COLORADO ID PRESSURE SOLUTION GROWTH; EQUILIBRIUM PRESSURE; PHASE-DIAGRAMS; GAN AB Thermochemical and phase diagram data for the Ga-N system were assessed by employing the CALPHAD method. A consistent model representation of available thermodynamic properties agrees well with the critically evaluated experimental data. Thermodynamic extrapolation/interpolation of these data was applied to estimate the sublimation and melting characteristics of the GaN compound: at atmospheric pressure of nitrogen, gallium nitride sublimates incongruently by decomposing into nitrogen-rich gas and gallium-rich liquid. but can melt congruently at high nitrogen pressure (approximate to4.9 GPa). C1 NIST, Div Met, Gaithersburg, MD 20899 USA. Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. RP Davydov, AV (reprint author), NIST, Div Met, Gaithersburg, MD 20899 USA. RI Davydov, Albert/F-7773-2010 OI Davydov, Albert/0000-0003-4512-2311 NR 20 TC 22 Z9 22 U1 2 U2 7 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD NOV PY 2001 VL 188 IS 1 BP 407 EP 410 DI 10.1002/1521-396X(200111)188:1<407::AID-PSSA407>3.0.CO;2-P PG 4 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 501LV UT WOS:000172686900089 ER PT J AU Soukhoveev, V Ivantsov, V Melnik, Y Davydov, A Tsvetkov, D Tsvetkova, K Nikitina, I Zubrilov, A Lavrentiev, A Dmitriev, V AF Soukhoveev, V Ivantsov, V Melnik, Y Davydov, A Tsvetkov, D Tsvetkova, K Nikitina, I Zubrilov, A Lavrentiev, A Dmitriev, V TI Characterization of 2.5-inch diameter bulk GaN grown from melt-solution SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT 4th International Conference on Nitride Semiconductors (ICNS-4) CY JUL 16-20, 2001 CL DENVER, COLORADO AB GaN bulk crystals up to 2.5-inch diameter were grown from melt-solution. Properties of these crystals were investigated using Auger electron spectroscopy, X-ray diffraction and photoluminescence. C1 TDI Inc, Gaithersburg, MD 20877 USA. NIST, Gaithersburg, MD 20899 USA. AF Ioffe Inst & Crystal Growth Res Ctr, St Petersburg 194021, Russia. RP Soukhoveev, V (reprint author), TDI Inc, Gaithersburg, MD 20877 USA. RI Davydov, Albert/F-7773-2010 OI Davydov, Albert/0000-0003-4512-2311 NR 3 TC 10 Z9 10 U1 0 U2 2 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD NOV PY 2001 VL 188 IS 1 BP 411 EP 414 DI 10.1002/1521-396X(200111)188:1<411::AID-PSSA411>3.3.CO;2-# PG 4 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 501LV UT WOS:000172686900090 ER PT J AU Tsvetkov, D Melnik, Y Davydov, A Shapiro, A Kovalenkov, O Lam, JB Song, JJ AF Tsvetkov, D Melnik, Y Davydov, A Shapiro, A Kovalenkov, O Lam, JB Song, JJ TI Growth of submicron AlGaN/GaN/AlGaN heterostructures by hydride vapor phase epitaxy (HVPE) SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT 4th International Conference on Nitride Semiconductors (ICNS-4) CY JUL 16-20, 2001 CL DENVER, COLORADO AB Multilayer AIGaN/GaN epitaxial structures were grown on SiC by HVPE method. Characterization of the grown structures was performed using SEM, SIMS, mercury probe, electroluminescence and photoluminescence techniques. Thicknesses of nitride layers in nanometer range were achieved. Stimulated emission from double confined heterostructure grown by HVPE was detected at room temperature under optical pumping. Short wave UV electroluminescence (lambda (max) approximate to 340-350 nm) was measured for p-AlGaN/n-AlGaN structures having up to 38 mol% and 9 mol% of AIN in p-AlGaN carrier emitter layers and n-AlGaN light emitting layers, respectively. C1 Technol & Devices Int Inc, Gaithersburg, MD 20877 USA. NIST, Gaithersburg, MD 20899 USA. Nobel Res Ctr, Ctr Laser & Photon Res, Stillwater, OK USA. RP Tsvetkov, D (reprint author), Technol & Devices Int Inc, 8660 Dakota Dr, Gaithersburg, MD 20877 USA. RI Davydov, Albert/F-7773-2010 OI Davydov, Albert/0000-0003-4512-2311 NR 2 TC 24 Z9 24 U1 1 U2 13 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD NOV PY 2001 VL 188 IS 1 BP 429 EP 432 DI 10.1002/1521-396X(200111)188:1<429::AID-PSSA429>3.3.CO;2-0 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 501LV UT WOS:000172686900094 ER PT J AU Mastro, MA Kryliouk, OM Reed, MD Anderson, TJ Davydov, A Shapiro, A AF Mastro, MA Kryliouk, OM Reed, MD Anderson, TJ Davydov, A Shapiro, A TI Thermal stability of MOCVD and HVPE GaN layers in H-2, HCl, NH3 and N-2 SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT 4th International Conference on Nitride Semiconductors (ICNS-4) CY JUL 16-20, 2001 CL DENVER, COLORADO ID DIODES AB This work represents a complete study of GaN annealed in H-2, HCl, NH3 and N-2. The GaN thermal behavior was evaluated by comparison of MOCVD and HVPE samples. The MOCVD films were found to obey a dissociative sublimation mechanism with only gaseous species forming, while the HVPE films reacted with ambient gases to form condensed Ga in addition to the gaseous species. Differences in crystal quality for MOCVD and HVPE samples resulting from the different growth mechanisms account for the observed difference. This analysis of the thermal stability of GaN is extended to include how polarity affects the thermal :behavior of GaN during growth and annealing of MOCVD and HVPE films. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. NIST, Div Met, Gaithersburg, MD 20899 USA. RP Mastro, MA (reprint author), Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. RI Davydov, Albert/F-7773-2010 OI Davydov, Albert/0000-0003-4512-2311 NR 13 TC 23 Z9 23 U1 1 U2 12 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD NOV PY 2001 VL 188 IS 1 BP 467 EP 471 DI 10.1002/1521-396X(200111)188:1<467::AID-PSSA467>3.3.CO;2-T PG 5 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 501LV UT WOS:000172686900102 ER PT J AU Kim, YK Stone, PM AF Kim, YK Stone, PM TI Ionization of boron, aluminum, gallium, and indium by electron impact SO PHYSICAL REVIEW A LA English DT Article ID ENCOUNTER-DIPOLE MODEL; CROSS-SECTIONS; ATOMS; APPROXIMATION; MOLECULES; HYDROGEN; IONS AB Measurements of electron impact ionization of neutral Al, Ga, and In show large cross sections compared to other elements in the same rows of the periodic table. Semiempirical and classical calculations of direct ionization cross sections are all substantially smaller. Calculations by McGuire [Phys. Rev. A 26, 125 (1982)] for aluminum that include excitations to autoionizing 3s3p(2) doublet levels are 2.5 times higher than experiment at the peak. We report the direct ionization cross sections based on the binary-encounter-Bethe model of Kim and Rudd [Phys. Rev. A 50, 3954 (1994)], which is an ab initio theory. We add the autoionization contribution using scaled plane-wave Born cross sections as recently developed by Kim [Phys. Rev. A 64, 032713 (2001)] for excitations to the first set of autoionizing levels. Dirac-Fock wave functions are used for the atomic structure. Our results are in excellent agreement with experimental values and support substantial contributions from excitation-autoionization to the total ionization cross sections for these elements. We also compare the total ionization cross section of boron to available theories, though no experimental data are available. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kim, YK (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 40 TC 53 Z9 53 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 2001 VL 64 IS 5 AR 052707 DI 10.1103/PhysRevA.64.052707 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 490VJ UT WOS:000172074200047 ER PT J AU Le Bigot, EO Indelicato, P Mohr, PJ AF Le Bigot, EO Indelicato, P Mohr, PJ TI QED self-energy contribution to highly excited atomic states SO PHYSICAL REVIEW A LA English DT Article ID STRONG COULOMB FIELD; COORDINATE-SPACE APPROACH; BEAM ION-TRAP; LAMB SHIFT; TRANSITION; HYDROGEN; SYSTEMS; SPECTRA; LEVEL; W52+ AB We present numerical values for the self-energy shifts predicted by QED for hydrogenlike ions (nuclear charge number 60 less than or equal to Z less than or equal to 110) with an electron in an n = 3. 4, or 5 level with high angular momentum (5/2 less than or equal to j less than or equal to 9/2). Its applications include precise predictions of transition energies and studies of the outer-shell structure of atoms and ions. C1 Ecole Normale Super, Lab Kastler Brossel, F-75252 Paris 05, France. Univ Paris 06, CNRS, UMR C8552, F-75252 Paris, France. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Le Bigot, EO (reprint author), Ecole Normale Super, Lab Kastler Brossel, Case 74,4 Pl Jussieu, F-75252 Paris 05, France. EM lebigot@spectro.jussieu.fr; paul@spectro.jussieu.fr; mohr@nist.gov RI Indelicato, Paul/D-7636-2011 OI Indelicato, Paul/0000-0003-4668-8958 NR 38 TC 22 Z9 22 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 2001 VL 64 IS 5 AR 052508 DI 10.1103/PhysRevA.64.052508 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 490VJ UT WOS:000172074200039 ER PT J AU Popovic, DB Djuric, N Holmberg, K Neau, A Dunn, GH AF Popovic, DB Djuric, N Holmberg, K Neau, A Dunn, GH TI Absolute cross sections for H+ formation from electron-impact dissociation of C2H+ and C2H2+ SO PHYSICAL REVIEW A LA English DT Article ID MOLECULAR-IONS; SPECTROSCOPY; EXCITATION; CHEMISTRY; D-2(+); D+ AB Absolute cross sections as a function of interaction energy were measured for H+ formation in electron-impact dissociation of C2H+ and C2H2+ in the energy range from threshold up to 50 eV. The crossed beams technique was used, and light fragment ions emerging from a heavy target were detected. A common feature of the studied targets was almost the same [( 1.3-1.7) x 10(-16) cm(2)] cross section for H+ production from 25 to 50 eV. The results were compared with our previous results for CDn+, and the observed propensity rules were found to apply in this case also. C1 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. RP Popovic, DB (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 23 TC 8 Z9 8 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 NOV PY 2001 VL 64 IS 5 AR 052709 DI 10.1103/PhysRevA.64.052709 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 490VJ UT WOS:000172074200049 ER PT J AU Wachter, J Walser, R Cooper, J Holland, M AF Wachter, J Walser, R Cooper, J Holland, M TI Equivalence of kinetic theories of Bose-Einstein condensation SO PHYSICAL REVIEW A LA English DT Article ID GAS AB We discuss the equivalence of two nonequilibrium kinetic theories that describe the evolution of a dilute. Bose-Einstein condensed atomic gas in a harmonic trap. The second-order kinetic equations of Walser et al. [Phys. Rev. A 63, 013607 (2001)] reduce to the Gross-Pitaevskii equation and the quantum Boltzmann equation in the low- and high-temperature limits, respectively, These kinetic equations thus describe the system in equilibrium (finite temperature) as well as in nonequilibrium (real time). We have found this theory to be equivalent to the nonequilibrium Green's function approach originally proposed by Kadanoff and Baym and more recently applied to inhomogeneous trapped systems by Imamovic-Tomasovic and Griffin [in Progress in Nonequilibrium Green's Functions, edited by M. Bonitz (World Scientific, Singapore, 2000), p. 404]. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Wachter, J (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 25 TC 27 Z9 27 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 NOV PY 2001 VL 64 IS 5 AR 053612 DI 10.1103/PhysRevA.64.053612 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 490VJ UT WOS:000172074200083 ER PT J AU Wasik, G Gawlik, W Zachorowski, J Kowal, Z AF Wasik, G Gawlik, W Zachorowski, J Kowal, Z TI Competition of dark states: Optical resonances with anomalous magnetic field dependence SO PHYSICAL REVIEW A LA English DT Article ID SPECTROSCOPY AB A different type of optical resonance has been observed in Doppler-free saturated absorption spectroscopy when the pump beam has elliptical polarization slightly deviating from the sigma (+) and the probe has sigma (-) polarization. An interpretation in terms of competition between two trap states and a dressed-atom model is presented. The observed extreme sensitivity of the resonance frequency to the external magnetic field is attributed to the "scissors effect" of the dressed states' crossing point. C1 Jagiellonian Univ, Inst Fizyki M Smoluchowskiego, PL-30059 Krakow, Poland. Univ Colorado, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RP Wasik, G (reprint author), Univ Erlangen Nurnberg, Inst Phys, Lehrstuhl Opt, Staudtstr 7-B2, D-91058 Erlangen, Germany. NR 8 TC 17 Z9 18 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 NOV PY 2001 VL 64 IS 5 AR 051802 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 490VJ UT WOS:000172074200008 ER PT J AU Popov, AP Pappas, DP AF Popov, AP Pappas, DP TI Surface magnetic phase diagram for a semi-infinite ferromagnet SO PHYSICAL REVIEW B LA English DT Article ID ANISOTROPY; REORIENTATION; TRANSITION AB The phase diagram for the orientation of the surface region is calculated in the parameter space defined by the surface and bulk anisotropy in semi-infinite ferromagnetic systems and in thin ferromagnet films, Surface magnetic canting always occurs when the magnitude of the surface anisotropy is comparable with the interlayer exchange interaction. Increasing the thickness of a thin film supported on a hard magnetic substrate induces a spin reorientation transition from the uniform, in-plane magnetic structure to a canted state. The inverse spin reorientation transition from the canted state to the uniform, in-plane magnetic structure with thickness is demonstrated for a thin film supported on a nonmagnetic substrate. A discrete layer-by-layer approach is developed and compared to the continuum approach. We consider the 1.5 atomic-layer system of Fe on Gd and find that it is a good physical realization of the model. C1 Moscow State Engn Phys Inst, Dept Mol Phys, Moscow 115407, Russia. Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Popov, AP (reprint author), Moscow State Engn Phys Inst, Dept Mol Phys, Kashirskoe Shosse 31, Moscow 115407, Russia. NR 10 TC 13 Z9 13 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 NOV 1 PY 2001 VL 64 IS 18 AR 184401 DI 10.1103/PhysRevB.64.184401 PG 11 WC Physics, Condensed Matter SC Physics GA 493TK UT WOS:000172239400055 ER PT J AU Punnoose, A Magnone, H Seehra, MS Bonevich, J AF Punnoose, A Magnone, H Seehra, MS Bonevich, J TI Bulk to nanoscale magnetism and exchange bias in CuO nanoparticles SO PHYSICAL REVIEW B LA English DT Article ID CUPRIC OXIDE; NEUTRON-SCATTERING; TRANSITIONS; ANISOTROPY; FERRIHYDRITE; DIFFRACTION; ANOMALIES; FERRITIN; FIELD; HEAT AB Detailed studies of the temperature (5-350 K) and magnetic field variations (up to H=50kOe) of the magnetization of CuO nanoparticles of nominal size range 37-6.6 nm are reported. These particles were synthesized by the sol-gel method in combination with high-temperature annealing, followed by structural characterization by x-ray diffraction and high-resolution transmission electron microscopy. With a decrease in particle size d from 37 to 10 nm, the unit-cell volume and b axis increased and the bulk Neel temperature TN decreased according to gamma (m) = -partial derivative lnT(N)/partial derivative ln b=30. For particles with d<10 nm, there is a more rapid lattice expansion and the magnetic susceptibility chi varied as l/d, accompanied by a weak ferromagnetic component and hysteresis loops. For the 6.6-nm particles for which detailed studies are reported, there is a rapid increase in the coercivity H-c and the remanence M-r below 40 K accompanied by an exchange bias H-E for the field-cooled samples in H=50 kOe. From 10 to 40 K, H-E decreases monotonically to zero. However, above 40 K. a symmetric hysteresis loop is observed, with H-c decreasing weakly towards zero as temperature increases towards 330 K. The hysteresis loop and the l/d variation of chi are interpreted in terms of uncompensated surface Cu2+ spins, whereas the transition at 40 K is suggested to be T-N of the spins in the core of 6.6-nm particles. Similarities to the hysteresis loops observed in the Permalloy/CoO system are noted. C1 W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. NIST, Gaithersburg, MD 20899 USA. RP Punnoose, A (reprint author), W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. EM mseehra@wvu.edu NR 36 TC 199 Z9 200 U1 10 U2 58 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2001 VL 64 IS 17 AR 174420 DI 10.1103/PhysRevB.64.174420 PG 8 WC Physics, Condensed Matter SC Physics GA 490AV UT WOS:000172027600068 ER PT J AU Wakimoto, S Tranquada, JM Ono, T Kojima, KM Uchida, S Lee, SH Gehring, PM Birgeneau, RJ AF Wakimoto, S Tranquada, JM Ono, T Kojima, KM Uchida, S Lee, SH Gehring, PM Birgeneau, RJ TI Diagonal static spin correlation in the low-temperature orthorhombic Pccn phase of La1.55Nd0.4Sr0.05CuO4 SO PHYSICAL REVIEW B LA English DT Article ID COPPER-OXIDE SUPERCONDUCTORS; 2-DIMENSIONAL HUBBARD-MODEL; NEUTRON-SCATTERING; DOPED LA2-XSR(X)CUO4; LONG-RANGE; LA2-XSRXCUO4; LA2-XBAXCUO4; ORDER; TRANSITION; ANTIFERROMAGNETISM AB Elastic neutron-scattering measurements have been performed on La1.55Nd0.4Sr0.05CuO4, which exhibits a structural phase transition at T(s)similar to 60 K from the low-temperature orthorhombic Bmab phase (labeled LTO1) to the low-temperature orthorhombic Pccn phase (labeled LTO2). At low temperatures. well below T-s, elastic magnetic peaks are observed at the "diagonal" incommensurate (IC) positions (0.1 +/- 0.055,0), with the modulation direction only along the orthorhombic b axis, just as in Nd-free La1.95Sr0.05CuO4. In the present study. the one dimensionality of the IC modulation, which is naturally explained by a stripe model, is clearly demonstrated with our "single-domain" crystal. The temperature dependence of the IC peak intensity suggests a substantial contribution from the Nd3+ spins below similar to3 K. Consistent with this. the L dependence of the magnetic scattering is accurately accounted for by a model in which the contribution of the Nd3+ spins is explicitly included. C1 MIT, Dept Phys, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. Natl Inst Stand & Technol, NCNR, Bethesda, MD 20889 USA. MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. RP Wakimoto, S (reprint author), Univ Toronto, Dept Phys, 60 St George St, Toronto, ON M5S 1A7, Canada. NR 34 TC 22 Z9 22 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2001 VL 64 IS 17 AR 174505 DI 10.1103/PhysRevB.64.174505 PG 8 WC Physics, Condensed Matter SC Physics GA 490AV UT WOS:000172027600076 ER PT J AU Yamaura, K Huang, Q Takayama-Muromachi, E AF Yamaura, K Huang, Q Takayama-Muromachi, E TI Crystal structure and magnetism of the linear-chain copper oxides Sr5Pb3-xBiCuO12 SO PHYSICAL REVIEW B LA English DT Article ID GROUND-STATE; SPIN GAP; LADDER; SUSCEPTIBILITY; ANTIFERROMAGNET; THERMODYNAMICS; (VO)2P2O7; PHASE AB The title quasi-one-dimensional copper oxides (0 less than or equal to x less than or equal to 0.4) were investigated by neutron diffraction and magnetic susceptibility studies. Polyhedral CuO4 units in the compounds were found to comprise linear chains at an interchain distance of approximately 10 Angstrom. The parent-chain compound (x = 0), however, shows less-anisotropic magnetic behavior above 2 K, although it is of substantially antiferromagnetic (mu (eff) = 1.85 mu (B) and Theta (W) = -46.4 K) spin-chain system. A magnetic cusp gradually appears at about 100 K in T vs chi with the Bi substitution. The cusp (x = 0.4) is fairly characterized by and therefore suggests the spin-gap nature at Delta /k(B) similar to 80 K. The chain compounds hold electrically insulating in the composition range. C1 Natl Inst Mat Sci, Adv Mat Lab, Tsukuba, Ibaraki 3050044, Japan. Japan Sci & Technol Corp, Kawaguchi, Saitama 3320012, Japan. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RP Yamaura, K (reprint author), Natl Inst Mat Sci, Adv Mat Lab, 1-1 Namiki, Tsukuba, Ibaraki 3050044, Japan. EM YAMAURA.Kazunari@nims.go.jp NR 17 TC 0 Z9 0 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 NOV 1 PY 2001 VL 64 IS 18 AR 184428 PG 7 WC Physics, Condensed Matter SC Physics GA 493TK UT WOS:000172239400082 ER PT J AU Baker-Jarvis, J Kabos, P AF Baker-Jarvis, J Kabos, P TI Dynamic constitutive relations for polarization and magnetization SO PHYSICAL REVIEW E LA English DT Article ID MEDIA AB In this paper we develop constitutive relations for materials where the magnetization and polarization may depend on both the electric and magnetic fields. The approach is general, and is based on a previously developed statistical-mechanical theory. We include the quadrupole-moment density as well as the dipole-moment density in the microscopic displacement field. This yields an electric gradient term in the constitutive equations. This leads to origin invariance in the multipole moments from which Maxwell's equations are defined. We present generalizations of Debye and Landau-Lifshitz equations of motion which are valid for nonequilibrium and contain memory. The reversible and relaxation terms in the polarization and magnetization evolution equations include the possibility of magnetoelectric coupling. Using constitutive relationship, we derive evolution equations for the displacement and induction fields from a Hamiltonian approach. 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,MS 813-01, Boulder, CO 80303 USA. NR 35 TC 17 Z9 17 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD NOV PY 2001 VL 64 IS 5 AR 056127 DI 10.1103/PhysRevE.64.056127 PN 2 PG 14 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 496QH UT WOS:000172407100038 PM 11736034 ER PT J AU Gebremichael, Y Schroder, TB Starr, FW Glotzer, SC AF Gebremichael, Y Schroder, TB Starr, FW Glotzer, SC TI Spatially correlated dynamics in a simulated glass-forming polymer melt: Analysis of clustering phenomena SO PHYSICAL REVIEW E LA English DT Review ID SUPERCOOLED ORTHO-TERPHENYL; LENNARD-JONES LIQUID; MODE-COUPLING-THEORY; NUCLEAR-MAGNETIC-RESONANCE; POTENTIAL-ENERGY LANDSCAPE; ANOMALOUS LIGHT-SCATTERING; MOLECULAR-DYNAMICS; STRUCTURAL RELAXATION; CHARACTERISTIC LENGTH; PARTICLE DISPLACEMENTS AB In recent years. experimental and computational studies have demonstrated that the dynamics of glass-forming liquids are spatially heterogeneous, exhibiting regions of temporarily enhanced or diminished mobility. Here we present a detailed analysis of dynamical heterogeneity in a simulated "bead-spring" model of a low-molecular-weight polymer melt. We investigate the transient nature and size distribution of clusters of "mobile" chain segments (monomers) as the polymer melt is cooled toward its glass transition. We also explore the dependence of this clustering on the way in which the mobile subset is defined, We show that the mean cluster size is time dependent with a peak at intermediate time, and that the mean cluster size at the peak time.-rows with decreasing temperature T. We show that for each T a particular fraction of particles maximizes the mean cluster size at some characteristic time, and this fraction depends on T, The growing size of the clusters demonstrates the growing range of correlated motion, previously reported for this same system [C. Beneman et al. Nature (London) 399, 246 (1999)]. The distribution of cluster sizes approaches a power law near the mode-coupling temperature, similar to behavior reported for a simulated binary mixture and a dense colloidal suspension, but with a different exponent, We calculate the correlation length of the clusters, and show that it exhibits similar temperature- and time-dependent behavior as the mean cluster size, with a maximum at intermediate time. We show that the characteristic time of the maximum cluster size follows the scaling predicted by mode-coupling theory (MCT) for the beta time scale, revealing a possible connection between spatially heterogeneous dynamics and MCT. C1 Natl Inst Stand & Technol, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Univ Maryland, Inst Phys Sci & Technol, Chem Phys Program, College Pk, MD 20742 USA. Univ Michigan, Dept Chem Engn, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. RP Glotzer, SC (reprint author), Natl Inst Stand & Technol, Ctr Theoret & Computat Mat Sci, Gaithersburg, MD 20899 USA. EM sglotzer@umich.edu RI Starr, Francis/C-7703-2012 NR 109 TC 78 Z9 78 U1 4 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD NOV PY 2001 VL 64 IS 5 AR 051503 DI 10.1103/PhysRevE.64.051503 PN 1 PG 13 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 496QF UT WOS:000172406900047 PM 11735925 ER PT J AU Milchberg, HM McNaught, SJ Parra, E AF Milchberg, HM McNaught, SJ Parra, E TI Plasma hydrodynamics of the intense laser-cluster interaction SO PHYSICAL REVIEW E LA English DT Article ID X-RAY-EMISSION; ATOMIC CLUSTERS; HOT NANOPLASMAS; GAS CLUSTERS; KR CLUSTERS; TEMPERATURE; ABSORPTION; IRRADIATION; EXPLOSIONS; GENERATION AB We present a one-dimensional hydrodynamic model of the intense laser-cluster interaction in which the laser field is treated self-consistently. We find that for clusters initially as small as similar to 25 Angstrom in radius nonuniform expansion of the heated material results in long-time resonance of the laser field at the critical density plasma laver. A significant result of this is that the ponderomotive force, which is enhanced at the critical density surface, can be large enough to strongly modify the plasma hydrodynamics, even at laser intensities as low as 10(15)W/cm(2) for 800 nm laser pulses. Simulations of our recent experiments in extreme ultraviolet and x-ray generation from clusters explain the dependence of generation efficiency on laser pulse width. C1 Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Milchberg, HM (reprint author), Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NR 29 TC 72 Z9 72 U1 0 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD NOV PY 2001 VL 64 IS 5 AR 056402 DI 10.1103/PhysRevE.64.056402 PN 2 PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 496QH UT WOS:000172407100100 ER PT J AU Hayashia, M Hashimoto, T Weber, M Grull, H Esker, AR Han, CC Satija, SK AF Hayashia, M Hashimoto, T Weber, M Grull, H Esker, AR Han, CC Satija, SK TI Transient interfacial instability in bilayer polymer films as observed by neutron reflectivity studies SO POLYMER LA English DT Article DE neutron and x-ray reflectivity; reactive blending; polymer interface ID BLENDS; INTERDIFFUSION; COMPATIBILIZATION; POLYSULFONE; SCATTERING; DIFFUSION; REFLECTOMETRY; MISCIBILITY; PARTICLES; POLYAMIDE AB Fundamental processes associated with reactive blending were explored for a system composed of polyamide (PA) and deuterated polysulfone having a reactive phthalic anhydride end group (R) (dPSU-R) diluted with a low molecular weight hydrogenous polysulfone (low-hPSU) by neutron reflectivity (NR). By preparing bilayer films composed of a mixed film of dPSU-R/low-hPSU and a PA film, an intriguing phenomenon was observed in NR studies during the thermal annealing of the sample. This phenomenon can be described as a transient instability of the interface between the PA layer and the dPSU-R/low-hPSU layer during annealing at temperatures high enough to allow chemical reactions to occur between the dPSU-R end groups and the terminal amino groups of PA, The signature for the interfacial instability was a transient disappearance of the NR fringes followed by a subsequent recovery of the fringes during additional annealing at high temperatures. The driving force for this phenomenon is rapid interdiffusion of a small, low molecular weight fraction of low-hPSU into the PA layer. A consequence of the rapid interdiffusion is an attendant Kirkendall shift of the interfacial position as the PSU layer shrinks. The magnitude of this special Kirdendall effect accompanying the interfacial instability is directly controlled by the amount of the miscible low molecular weight fraction of low-hPSU present in the normally immiscible PSU/PA pair. (C) 2001 Published by Elsevier Science Ltd. C1 Kyoto Univ, Dept Polymer Chem, Grad Sch Engn, Sakyo Ku, Kyoto 6068201, Japan. BASF AG, Polymer Res Lab, Engn Plast, D-67056 Ludwigshafen, Germany. NIST, Div Polymers, Gaithersburg, MD 20899 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Hashimoto, T (reprint author), Kyoto Univ, Dept Polymer Chem, Grad Sch Engn, Sakyo Ku, Kyoto 6068201, Japan. NR 37 TC 1 Z9 1 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD NOV PY 2001 VL 42 IS 24 BP 9771 EP 9782 DI 10.1016/S0032-3861(01)00519-5 PG 12 WC Polymer Science SC Polymer Science GA 469QH UT WOS:000170826000016 ER PT J AU Pratt, KW Koch, WF Wu, YC Berezansky, PA AF Pratt, KW Koch, WF Wu, YC Berezansky, PA TI Molality-based primary standards of electrolytic conductivity - (IUPAC technical report) SO PURE AND APPLIED CHEMISTRY LA English DT Article ID KCL SOLUTIONS; ABSOLUTE DETERMINATION; 50-DEGREES-C; 0-DEGREES-C AB New values of electrolytic conductivity were determined for aqueous KCl solutions with molalities of 0.01, 0.1, and 1.0 mol/kg in the temperature range 0 to 50 degreesC, at 5 K intervals. Expanded uncertainties, 2u(c), were also calculated in accordance with the presently accepted protocol for the treatment of uncertainty. The new conductivity values are recommended as primary standards of electrolytic conductivity based on molality. They replace the previous values, based on the nonstandard demal scale, which were determined only at 0, 18, and 25 degreesC. The accuracy of the technique used was evaluated by repeating the determination of the previously recommended demal-based IUPAC standards of electrolytic conductivity and through comparison with other absolute measurements. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Pratt, KW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 14 TC 42 Z9 43 U1 0 U2 14 PU INT UNION PURE APPLIED CHEMISTRY PI RES TRIANGLE PK PA 104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USA SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD NOV PY 2001 VL 73 IS 11 BP 1783 EP 1793 DI 10.1351/pac200173111783 PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA 524FY UT WOS:000174003500009 ER PT J AU Tatarskii, VI Muschinski, A AF Tatarskii, VI Muschinski, A TI The difference between Doppler velocity and real wind velocity in single scattering from refractive index fluctuations SO RADIO SCIENCE LA English DT Article ID RADAR OBSERVATIONS; TROPOSPHERE; TURBULENCE; PROFILERS AB Scattering of electromagnetic waves by turbulence is considered. It is shown that Doppler velocity (the ratio of Doppler shift and Bragg wave number) includes two terms: The first is the mean radial velocity in the scattering volume, and the second is what we call the ''correlation velocity,'' caused by a correlation between the fluctuations of velocity and those of refractive index. The correlation velocity is proportional to the imaginary part of the Bragg wave vector component of the three-dimensional spatial cross spectrum of refractive index and radial wind velocity. In the electromagnetic case in the atmosphere the correlation velocity provides information about the combination of humidity and heat fluxes. In the acoustic case it provides information about the flux of sensible heat in the atmosphere or about some combination of salinity and heat fluxes in water. In situ measurements of the temperature, humidity, and wind fluctuations in the atmosphere are analyzed to estimate the magnitude of the correlation velocity. It appears that the correlation velocity, which cannot be directly measured with existing radar wind profilers, could be separated from the total Doppler shift by means of bistatic radars. A potential application is the profiling of fluxes using bistatic systems. C1 NOAA, Environm Technol Lab, Boulder, CO 80305 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Tatarskii, VI (reprint author), NOAA, Environm Technol Lab, 325 Broadway,R ET4, Boulder, CO 80305 USA. NR 21 TC 9 Z9 9 U1 2 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD NOV-DEC PY 2001 VL 36 IS 6 BP 1405 EP 1423 DI 10.1029/2000RS002376 PG 19 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 508AT UT WOS:000173065300013 ER PT J AU Wells, OC McGlashan-Powell, M Vladar, AE Postek, MT AF Wells, OC McGlashan-Powell, M Vladar, AE Postek, MT TI Application of the low-loss scanning electron microscope image to integrated circuit technology - Part II - Chemically-mechanically planarized samples SO SCANNING LA English DT Article DE low-loss electrons; chemically-mechanically planarized; backscattered electrons AB Chemical-mechanical planarization (CMP) is a process that gives a flat surface on a silicon wafer by removing material from above a chosen level. This flat surface must then be reviewed (typically using a laser) and inspected for scratches and other topographic defects. This inspection has been done using both the atomic force microscope (AFM) and the scanning electron microscope (SEM), each of which has its own advantages and disadvantages. In this study, the low-loss electron (LLE) method in the SEM was applied to CMP samples at close to a right angle to the beam. The LLEs show shallower topographic defects more clearly than it is possible with the secondary electron (SE) imaging method. These images were then calibrated and compared with those obtained using the AFM, showing the value of both methods. It is believed that the next step is to examine such samples at a right angle to the beam in the SEM using the magnetically filtered LLE imaging method. C1 IBM Corp, Thomas J Watson Res Ctr, Div Res, Yorktown Hts, NY 10598 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Wells, OC (reprint author), IBM Corp, Thomas J Watson Res Ctr, Div Res, POB 218,20-206, Yorktown Hts, NY 10598 USA. NR 10 TC 3 Z9 3 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0161-0457 J9 SCANNING JI Scanning PD NOV-DEC PY 2001 VL 23 IS 6 BP 366 EP 371 PG 6 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA 499WT UT WOS:000172594100002 PM 11770931 ER PT J AU Portier-Fozzani, F Aschwanden, M Demoulin, P Neupert, W Delaboudinere, JP AF Portier-Fozzani, F Aschwanden, M Demoulin, P Neupert, W Delaboudinere, JP CA EIT Team TI Measurement of coronal magnetic twists during loop emergence of NOAA 8069 SO SOLAR PHYSICS LA English DT Article ID SOLAR ACTIVE REGIONS; VLA STEREOSCOPY; CONSTANT-ALPHA; FLUX; EIT; HELICITY; EVOLUTION; FIELDS; TUBES AB Emerging coronal loops were studied with extreme ultraviolet observations performed by SOHO/EIT on 5 and 6 August 1997 for NOAA 8069. Physical parameters (size and twist) were determined by a new stereoscopic method. The flux tubes were measured twisted when first observed by EIT. After emerging, they de-twisted as they expanded, which corresponds to a minimization of the energy. Different scenarios which take into account the conservation of the magnetic helicity are discussed in relation with structure and temperature variations. C1 Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. Lockheed Martin Palo Alto Adv Technol Ctr, Palo Alto, CA USA. Observ Paris, DASOP, Meudon, France. NOAA, SEC, Boulder, CO USA. CNRS, Astron Spatiale Lab, UPR, F-13012 Marseille, France. RP Demoulin, P (reprint author), Max Planck Inst Aeron, Max Planck Str 2, D-37191 Katlenburg Lindau, Germany. OI Demoulin, Pascal/0000-0001-8215-6532 NR 38 TC 13 Z9 13 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD NOV PY 2001 VL 203 IS 2 BP 289 EP 308 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 506NB UT WOS:000172977700006 ER PT J AU Hurley, DC Tewary, VK Richards, AJ AF Hurley, DC Tewary, VK Richards, AJ TI Thin-film elastic-property measurements with laser-ultrasonic SAW spectrometry SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 28th International Conference on Metallurgical Coatings and Thin Films CY APR 30-MAY 05, 2001 CL SAN DIEGO, CALIFORNIA SP AVS Sci & Technol Soc, Adv Surface Engn Div DE elastic properties; surface acoustic waves; titanium nitride ID SOLIDS; WAVES AB We have developed laser-ultrasonic methods to evaluate the elastic properties of thin films. Our method, called SAW spectrometry, used broadband surface acoustic waves (SAWS) generated by a line-focused, pulsed laser. SAWS with frequency components up to similar to 400 MHz were detected by a Michelson interferometer. Dispersion relations for the phase velocity vs. frequency were calculated from displacement waveforms acquired over a range of source-detector separations. Quantitative elastic-property information was obtained from the dispersion relations with a newly developed inversion algorithm. The algorithm was based on the delta-function representation of the elastodynamic Green's function for anisotropic layered systems. The methods were tested by applying them to a molybdenum film on a single-crystal silicon wafer. Values obtained for the film's Poisson ratio and Young's modulus were consistent with literature values. We also used SAW spectrometry to investigate several samples containing titanium nitride films on silicon substrates. Assuming literature values for the filet density and Poisson ratio, we applied the inversion algorithm to determine the thickness and Young's modulus of each film, Young's modulus in the films was found to increase monotonically with increasing film thickness from 368 to 453 GPa. Inversion results for the film thickness were in very good agreement with destructive measurements of the actual thicknesses. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80305 USA. CSIRO, Telecommun & Ind Phys, Lindfield, NSW 2070, Australia. RP Hurley, DC (reprint author), Natl Inst Stand & Technol, Div Mat Reliabil, 325 Broadway, Boulder, CO 80305 USA. NR 16 TC 36 Z9 37 U1 0 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD NOV 1 PY 2001 VL 398 BP 326 EP 330 DI 10.1016/S0040-6090(01)01338-4 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 505GZ UT WOS:000172906200056 ER PT J AU Nitschke, P Burnett, J Kelly, BC AF Nitschke, P Burnett, J Kelly, BC TI Age and growth verification for cunner in Western Cape Cod Bay, Massachusetts, using tag-recapture data SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID TEMPERATE REEF FISH; TAUTOGOLABRUS-ADSPERSUS WALBAUM; PARAMETERS; RECRUITMENT; SETTLEMENT; BEHAVIOR; SURVIVAL; CURVE AB Information obtained from tag-recapture data can provide estimates of growth that are similar to those obtained from age-length data. A total of 5,760 cunners Tautogolabrus adspersus were tagged and released during 1992-1996; 385 fish that had been at large for at least one winter were recaptured. Otoliths were collected from 688 other fish for age determination. Growth parameter estimates (K and L-infinity) were very similar between the von Bertalanffy model (which used age-length data) and Fabens' method (which used tag-recapture data). The recapture lengths and times at large for individual tagged fish calculated from both models were similar to the observed recapture lengths and times at large. An age distribution derived for recaptured fish using an age-length key was similar to one estimated from tagging ages plus known times at large. Otolith rings appear to be an appropriate indicator of age for cunners. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. Massachusetts Div Marine Fisheries, Pocasset, MA 02559 USA. RP Nitschke, P (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. NR 39 TC 4 Z9 4 U1 1 U2 2 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD NOV PY 2001 VL 130 IS 6 BP 1150 EP 1163 DI 10.1577/1548-8659(2001)130<1150:AAGVFC>2.0.CO;2 PG 14 WC Fisheries SC Fisheries GA 502HP UT WOS:000172738200011 ER PT J AU Boyle, DP Gupta, HV Sorooshian, S Koren, V Zhang, ZY Smith, M AF Boyle, DP Gupta, HV Sorooshian, S Koren, V Zhang, ZY Smith, M TI Toward improved streamflow forecasts: Value of semidistributed modeling SO WATER RESOURCES RESEARCH LA English DT Article ID HYDROLOGIC-MODELS; IMPROVED CALIBRATION; RUNOFF MODEL; RAINFALL; SENSITIVITY; SYSTEM AB The focus of this study is to assess the performance improvements of semidistributed applications of the U.S. National Weather Service Sacramento Soil Moisture Accounting model on a watershed using radar-based remotely sensed. precipitation data. Specifically, performance comparisons are made within an automated multicriteria calibration framework to evaluate the benefit of "spatial distribution" of the model input (precipitation), structural components (soil moisture and streamflow routing computations), and surface characteristics (parameters). A comparison of these results is made with those obtained through manual calibration. Results indicate that for the study watershed, there are performance improvements associated with semidistributed model applications when the watershed is partitioned into three subwatersheds; however, no additional benefit is gained from increasing the number of subwatersheds from three to eight. Improvements in model performance are demonstrably related to the spatial distribution of the model input and streamflow routing. Surprisingly, there is no improvement associated with the distribution of the surface characteristics (model parameters). C1 Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. NOAA, Natl Weather Serv, Hydrol Lab, Off Hydrol Dev, Silver Spring, MD 20910 USA. RP Boyle, DP (reprint author), Univ & Community Coll Syst Nevada, Desert Res Inst, Reno, NV USA. RI Gupta, Hoshin/D-1642-2010; sorooshian, soroosh/B-3753-2008 OI Gupta, Hoshin/0000-0001-9855-2839; sorooshian, soroosh/0000-0001-7774-5113 NR 27 TC 123 Z9 125 U1 2 U2 11 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 NOV PY 2001 VL 37 IS 11 BP 2749 EP 2759 DI 10.1029/2000WR000207 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 485KY UT WOS:000171754600010 ER PT J AU Bouldin, C Sims, J Hung, H Rehr, JJ Ankudinov, AL AF Bouldin, C Sims, J Hung, H Rehr, JJ Ankudinov, AL TI Rapid calculation of x-ray absorption near edge structure using parallel computation SO X-RAY SPECTROMETRY LA English DT Article AB Modeling x-ray absorption near edge structure (XANES) requires computationally intensive calculations. We show that parallel processing can reduce the time required for XANES calculations by a factor of up to 50 over standard desktop computers. Parallel processing is implemented in our codes using the Message Passing Interface (MPI) and is portable across most hardware and operating systems. We demonstrate the inverse scaling of the parallel algorithm with the number of processors, and discuss how this approach to parallel processing could be implemented in other multiple-scattering calculations. Faster calculations should improve the applicability of ab initio XANES studies to many materials science problems. Published in 2001 by John Wiley & Sons, Ltd. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. RP Bouldin, C (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8522, Gaithersburg, MD 20899 USA. NR 7 TC 10 Z9 10 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0049-8246 J9 X-RAY SPECTROM JI X-Ray Spectrom. PD NOV-DEC PY 2001 VL 30 IS 6 BP 431 EP 434 DI 10.1002/xrs.524 PG 4 WC Spectroscopy SC Spectroscopy GA 495NT UT WOS:000172347800012 ER PT J AU Matsumoto, K Broecker, WS Clark, E McCorkle, DC Martin, WR Hajdas, I AF Matsumoto, K Broecker, WS Clark, E McCorkle, DC Martin, WR Hajdas, I TI Can deep ocean carbonate preservation history inferred from atmospheric pCO(2) account for C-14 and %CaCO3 profiles on the Ontong-Java Plateau? SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE C-14; Pb-210; bioturbation; deglaciation; Ontong-Java Plateau; deep-sea environment sediments; Pacific Ocean ID IN-SITU MEASUREMENTS; VOSTOK ICE CORE; EQUATORIAL PACIFIC; CALCITE DISSOLUTION; ORGANIC-CARBON; BOX CORES; SEDIMENTS; SEA; PB-210; CACO3 AB Bulk C-14 and Pb-210(excess) measurements were made on box cores from water depths of similar to 2300 and similar to 4200 in from the equator on the Ontong-Java Plateau. A sediment mixed layer thickness of approximately 6 cm and a mixing rate of 20-45 cm(2)/kyr are inferred from these radionuclide measurements and model simulations of their depth profiles. Using these sediment mixing characteristics, the model is then forced with a deep sea carbonate preservation history derived from an ice core atmospheric pCO(2) record, in order to examine whether the derived history can account for depth profiles of C-14 age and CaCO3 content from the deep western equatorial Pacific. Results show that C-14 and %CaCO3 data from the deep site can be simulated simultaneously with some success using the assumed carbonate preservation history and a time-varying non-carbonate flux function. However, the model is unable to use the same forcing functions to simulate the C-14 and %CaCO3 data from the shallower core. These results suggest that local carbonate accumulation is not driven simply by generalized deep water carbonate chemistry inferred from atmospheric pCO2. Potentially important local processes and aspects of the model that may have contributed to the results are also discussed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. Columbia Univ, Dept Earth & Environm Sci, New York, NY USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. ETH Honggerberg, ITP, CH-8093 Zurich, Switzerland. RP Matsumoto, K (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. EM kmatsumo@splash.princeton.edu RI Hajdas, Irka/C-6696-2011 NR 34 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT 30 PY 2001 VL 192 IS 3 BP 319 EP 329 DI 10.1016/S0012-821X(01)00412-5 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 488BM UT WOS:000171914500006 ER PT J AU Bianco-Peled, H Dori, Y Schneider, J Sung, LP Satija, S Tirrell, M AF Bianco-Peled, H Dori, Y Schneider, J Sung, LP Satija, S Tirrell, M TI Structural study of langmuir monolayers containing lipidated poly(ethylene glycol) and peptides SO LANGMUIR LA English DT Article ID AIR-WATER-INTERFACE; PHOSPHOLIPID MONOLAYERS; NEUTRON REFLECTIVITY; ADSORBED POLYMER; GOOD SOLVENT; ADSORPTION; LIPOSOMES; BILAYERS; CHAINS; THERMODYNAMICS AB The structure of Langmuir monolayers containing either a lipidated poly(ethylene glycol) (PEG-lipid) or a lipidated peptide (peptide-amphiphile) or a binary mixture of both was studied using neutron reflectivity. The PEG portion of the PEG-lipid extends into the water, forming dense polymer "brushes". The PEG volume fraction profiles and the brush height were evaluated from the reflectivity curves for monolayers containing PEG-lipids with PEG molecular masses of 120, 750, 2000, and 5000 Da at various grafting densities. At relatively low surface densities, the segmental concentration profile for DSPE-PEG5000 (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[(ethylene glycol)(n)], DSPE) and DSPE-PEG2000 was well-described by the parabolic profile predicted by the analytical self-consistent mean field theory. An increase in the surface density produced "flattening" of the profile, which became more pronounced as the chain length decreased. The dependence of the brush height on the surface density and the chain length was in close agreement with the power laws predicted by the self-consistent mean field and the scaling theories. Unlike the flexible PEG chains, the peptide-amphiphile that was used in this study has a stiff conformation. The headgroup is oriented perpendicular to the air-water interface, and this configuration is nearly unaffected by changes in the surface density. Incorporation of the peptide-amphiphile into a PEG-lipid monolayer results in perturbation of the brush structure, due to the enhanced configuration constraints. These studies enable us to gauge how the tethered peptide in the monolayer can be exposed or masked when mixed with tethered PEG chains. C1 Univ Calif Santa Barbara, Dept Chem Engn, Mat Res Lab, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Dept Mat, Mat Res Lab, Santa Barbara, CA 93106 USA. Technion Israel Inst Technol, Dept Chem Engn, IL-32000 Haifa, Israel. Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Tirrell, M (reprint author), Univ Calif Santa Barbara, Dept Chem Engn, Mat Res Lab, Santa Barbara, CA 93106 USA. RI Schneider, James/C-4095-2008 OI Schneider, James/0000-0001-8016-8687 NR 37 TC 32 Z9 33 U1 1 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 OCT 30 PY 2001 VL 17 IS 22 BP 6931 EP 6937 DI 10.1021/la990383i PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 486LA UT WOS:000171818200029 ER PT J AU Munoz, M Qian, GG Karar, N Cheng, H Saveliev, IG Garcia, N Moffat, TP Chen, PJ Gan, L Egelhoff, WF AF Munoz, M Qian, GG Karar, N Cheng, H Saveliev, IG Garcia, N Moffat, TP Chen, PJ Gan, L Egelhoff, WF TI Ballistic magnetoresistance in a nanocontact between a Ni cluster and a magnetic thin film SO APPLIED PHYSICS LETTERS LA English DT Article AB We present measurements of ballistic magnetoresistance in nanocontacts grown by electrodeposition of Ni microclusters on magnetic thin films covered by aluminum oxide layers, using a technique proposed by Schad [D. Allen, R. Schad, G. Zangari, I. Zana, D. Yang, M. C. Tondra, and D. Wang, J. Vac. Sci. Technol. A. 18, 1830 (2000); Appl. Phys. Lett. 76, 407 (2000); D. Allen, R. Schad, G. Zangari, I. Zana, D. Yang, M. C. Tondra, D. Wang, and D. Reed, J. Appl. Phys. 89, 6662 (2001)]. The measurements are made on single Ni clusters in contact with a Ni and Co thin film. We measure the magnetoresistance and observe the relaxation of the magnetization and electrical resistance as a function of time. The clusters are electrodeposited under several different experimental conditions. Some are deposited randomly on an unpatterned film and some through various patterned photoresists that control the location at which the cluster is grown. The typical contact size is estimated from the electrical resistance to be 10-30 nm. Ballistic magnetoresistance values up to 14% are obtained in these first experiments. (C) 2001 American Institute of Physics. C1 CSIC, Lab Fis Sistemas Pequenos & Nanotecnol, E-28006 Madrid, Spain. Natl Inst Stand & Technol, Gaithersburg, MD 20988 USA. RP Garcia, N (reprint author), CSIC, Lab Fis Sistemas Pequenos & Nanotecnol, Serrano 144, E-28006 Madrid, Spain. RI Munoz, Manuel/D-9532-2011; Munoz, M. Carmen/F-6970-2012 OI Munoz, M. Carmen/0000-0003-1504-1692 NR 11 TC 11 Z9 11 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 29 PY 2001 VL 79 IS 18 BP 2946 EP 2948 PG 3 WC Physics, Applied SC Physics GA 484ZM UT WOS:000171726300028 ER PT J AU Kumar, SK Douglas, JF AF Kumar, SK Douglas, JF TI Gelation in physically associating polymer solutions SO PHYSICAL REVIEW LETTERS LA English DT Article ID THERMOREVERSIBLE GELATION; GLASS-TRANSITION; LATTICE MODEL; GELS; DYNAMICS; ELASTICITY; LIQUID AB Simulations were performed on solutions of associating polymers, where the pairing energy between "stickers" is comparable to thermal energy, to gain insights into the nature of reversible gelation. At high temperatures, interchain associations relax over microscopic time scales, so that geometrical percolation is unrelated to macroscopic gelation. However, with decreasing temperature, the stickers undergo a clustering "transition," resulting in a transient localization of stickers and hence the chains. These findings imply a close similarity between the dynamics of associating polymer solutions and vitrification of glass-forming liquids, in agreement with many experimental results. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. RP Kumar, SK (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. EM kumar@plmsc.psu.edu NR 35 TC 97 Z9 98 U1 3 U2 34 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 29 PY 2001 VL 87 IS 18 AR 188301 DI 10.1103/PhysRevLett.87.188301 PG 4 WC Physics, Multidisciplinary SC Physics GA 487ZL UT WOS:000171909500064 ER PT J AU Mitchell, TB Bollinger, JJ Itano, WM Dubin, DHE AF Mitchell, TB Bollinger, JJ Itano, WM Dubin, DHE TI Stick-slip dynamics of a stressed ion crystal SO PHYSICAL REVIEW LETTERS LA English DT Article ID SELF-ORGANIZED CRITICALITY; PENNING TRAP; NONNEUTRAL PLASMAS; FLUCTUATIONS; TRANSPORT; FRICTION; FIELD; WALL AB We study the control of the rotation of a laser-cooled ion crystal in a Penning trap by a rotating electric field perturbation. We show that application of a small torque produces sudden angular jumps or "slips" of the crystal orientation spaced by intervals when the crystal is phase locked or "stuck" relative to the rotating perturbation. The distribution of angular slips is described by a power law, where the power-law exponent depends on the applied torque. We believe this system is driven by a constant force and small perturbations or thermal effects trigger the slips. C1 Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80305 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Mitchell, TB (reprint author), Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA. NR 29 TC 28 Z9 29 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 29 PY 2001 VL 87 IS 18 AR 183001 DI 10.1103/PhysRevLett.87.183001 PG 4 WC Physics, Multidisciplinary SC Physics GA 487ZL UT WOS:000171909500015 ER PT J AU Nakao, H Ohwada, K Takesue, N Fujii, Y Isobe, M Ueda, Y von Zimmermann, M Hill, JP Gibbs, D Woicik, JC Koyama, I Murakami, Y AF Nakao, H Ohwada, K Takesue, N Fujii, Y Isobe, M Ueda, Y von Zimmermann, M Hill, JP Gibbs, D Woicik, JC Koyama, I Murakami, Y TI Comment on "x-ray anomalous scattering study of a charge-ordered state in NaV2O5" - Reply SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material C1 High Energy Accelerator Res Org, KEK, Inst Mat Struct Sci, Photon Factory, Tsukuba, Ibaraki 3050801, Japan. Univ Tokyo, Inst Solid State Phys, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. Univ Tokyo, Inst Solid State Phys, Mat Design & Charecterizat Lab, Kashiwa, Chiba 2778581, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Nakao, H (reprint author), High Energy Accelerator Res Org, KEK, Inst Mat Struct Sci, Photon Factory, Tsukuba, Ibaraki 3050801, Japan. RI Isobe, Masahiko/B-5616-2015 NR 6 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 29 PY 2001 VL 87 IS 18 AR 189703 DI 10.1103/PhysRevLett.87.189703 PG 1 WC Physics, Multidisciplinary SC Physics GA 487ZL UT WOS:000171909500071 ER PT J AU Hansen, J Ruedy, R Sato, M Imhoff, M Lawrence, W Easterling, D Peterson, T Karl, T AF Hansen, J Ruedy, R Sato, M Imhoff, M Lawrence, W Easterling, D Peterson, T Karl, T TI A closer look at United States and global surface temperature change SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CLIMATOLOGICAL TIME-SERIES; CLIMATE-CHANGE; NETWORK; TRENDS; SIMULATION; SATELLITE; FORCINGS; MINIMUM; MAXIMUM; MODEL AB We compare the United States and global surface air temperature changes of the past century using the current Goddard Institute for Space Studies (GISS) analysis and the U.S. Historical Climatology Network (USHCN) record [Karl et al., 1990]. Changes in the GISS analysis subsequent to the documentation by Hansen et al. [1999] are as follows: (1) incorporation of corrections for time-of-observation bias and station history adjustments in the United States based on Easterling et al. [ 1996a], (2) reclassification of rural, small-town, and urban stations in the United States, southern Canada, and northern Mexico based on satellite measurements of night light intensity [Imhoff et al., 1997], and (3) a more flexible urban adjustment than that employed by Hansen et al. [1999], including reliance: on only unlit stations in the United States and rural stations in the rest of the world for determining long-term trends. We find evidence of local human effects ("urban warming") even in suburban and small-town surface air temperature records, but the effect is modest in magnitude and conceivably could be an artifact of inhomogeneities in the station records. We suggest further studies, including more complete satellite night light analyses. which may clarify the potential urban effect. There are inherent uncertainties in the long-term temperature change at least of the order of 0.1 degreesC for both the U.S. mean and the global mean. Nevertheless, it is clear that the post- 1930s cooling was much larger in the United States than in the global mean. The U.S. mean temperature has now reached a level comparable to that of the 1930s, while the global temperature is now far above the levels earlier in the century. The successive periods of global warming (1900-1940), cooling (1940-1965), and warming (1965-2000) in the 20th century show distinctive patterns of temperature change suggestive of roles for both climate forcings and dynamical variability. The U.S. was warm in 2000 but cooler than the warmest years in the 1930s and 1990s. Global temperature was moderately high in 2000 despite a lingering La Nina in the Pacific Ocean. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. NASA, Goddard Space Flight Ctr, New York, NY 10025 USA. NOAA, Natl Climat Data Ctr, Asheville, NC 28801 USA. RP Hansen, J (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM hansen@giss.nasa.gov NR 40 TC 330 Z9 362 U1 3 U2 58 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 2001 VL 106 IS D20 BP 23947 EP 23963 DI 10.1029/2001JD000354 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 489CG UT WOS:000171974000001 ER PT J AU Garand, L Turner, DS Larocque, M Bates, J Boukabara, S Brunel, P Chevallier, F Deblonde, G Engelen, R Hollingshead, M Jackson, D Jedlovec, G Joiner, J Kleespies, T McKague, DS McMillin, L Moncet, JL Pardo, JR Rayer, PJ Salathe, E Saunders, R Scott, NA Van Delst, P Woolf, H AF Garand, L Turner, DS Larocque, M Bates, J Boukabara, S Brunel, P Chevallier, F Deblonde, G Engelen, R Hollingshead, M Jackson, D Jedlovec, G Joiner, J Kleespies, T McKague, DS McMillin, L Moncet, JL Pardo, JR Rayer, PJ Salathe, E Saunders, R Scott, NA Van Delst, P Woolf, H TI Radiance and Jacobian intercomparison of radiative transfer models applied to HIRS and AMSU channels SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-VAPOR; ATMOSPHERIC TRANSMITTANCE; INFRARED RADIANCES; ABSORBING GAS; COOLING RATES; ASSIMILATION; ABSORPTION; BAND; PARAMETERS; FLUXES AB The goals of this study are the evaluation of current fast radiative transfer models (RTMs) and line-by-line (LBL) models. The intercomparison focuses on the modeling of 11 representative sounding channels routinely used at numerical weather prediction centers: 7 HIRS (High-resolution Infrared Sounder) and 4 AMSU (advanced microwave sounding unit) channels. Interest in this topic was evident by the participation of 24 scientists from 16 institutions. An ensemble of 42 diverse atmospheres was used and results compiled for 19 infrared models and 10 microwave models, including several LBL RTMs. For the first time, not only radiances but also Jacobians (of temperature, water vapor, and ozone) were compared to various LBL models for many,channels. In the infrared, LBL models typically agree to within 0.05-0.15 K (standard deviation) in terms of top-of-the-atmosphere brightness temperature (BT) Individual differences up to 0.5 K still exist, systematic in some channels, and linked to the type of atmosphere in others. The best fast models emulate LBL BTs to within 0.25 K, but no model achieves this desirable level of success for all channels. The ozone modeling is particularly challenging. In the microwave, fast models generally do quite well against the LBL model to which they were tuned. However, significant differences were noted among LBL models. Extending the intercomparison to the Jacobians proved very useful in detecting subtle or more obvious modeling errors. In addition, total and single gas optical depths were calculated, which provided additional insight on the nature of differences. C1 Meteorol Serv Canada, Dorval, PQ H9P 1J3, Canada. NOAA, ERL, Boulder, CO 80303 USA. Meteorol Serv Canada, Downsview, ON M3H 5T4, Canada. Atmospher & Environm Res Inc, Cambridge, MA 02139 USA. Meteo France, Lannion, France. ECMWF, Reading, Berks, England. European Ctr Medium Range Weather Forecasts, Reading, Berks, England. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Raytheon Co, Aurora, CO 80011 USA. NASA, MSFC, Huntsville, AL 35805 USA. NASA, DAO, Greenbelt, MD 20771 USA. NOAA, NESDIS, Camp Springs, CA 91125 USA. CALTECH, Pasadena, CA 91125 USA. Meteorol Off, Bracknell RB12 2SZ, Berks, England. Univ Washington, Seattle, WA 98195 USA. CNRS, Meteorol Dynam Lab, Palaiseau, France. Univ Wisconsin, Madison, WI 53706 USA. RP Garand, L (reprint author), Meteorol Serv Canada, 2121 Trans Canada Highway, Dorval, PQ H9P 1J3, Canada. EM louis.garand@ec.gc.ca RI Boukabara, Sid Ahmed/F-5577-2010; Kleespies, Thomas/F-5598-2010; Joiner, Joanna/D-6264-2012; McKague, Darren/J-2590-2012; Bates, John/D-1012-2009; Jackson, Darren/D-5506-2015; Chevallier, Frederic/E-9608-2016 OI Boukabara, Sid Ahmed/0000-0002-1857-3806; McKague, Darren/0000-0003-0297-0388; Bates, John/0000-0002-8124-0406; Jackson, Darren/0000-0001-5211-7866; Chevallier, Frederic/0000-0002-4327-3813 NR 39 TC 70 Z9 74 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 2001 VL 106 IS D20 BP 24017 EP 24031 DI 10.1029/2000JD000184 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 489CG UT WOS:000171974000007 ER PT J AU Takegawa, N Kita, K Kondo, Y Matsumi, Y Parrish, DD Holloway, JS Koike, M Miyazaki, Y Toriyama, N Kawakami, S Ogawa, T AF Takegawa, N Kita, K Kondo, Y Matsumi, Y Parrish, DD Holloway, JS Koike, M Miyazaki, Y Toriyama, N Kawakami, S Ogawa, T TI Airborne vacuum ultraviolet resonance fluorescence instrument for in situ measurement of CO SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-MONOXIDE; FAST-RESPONSE; REACTIVE NITROGEN; WESTERN PACIFIC; TROPOSPHERE; DISTRIBUTIONS; OZONE; OCEAN AB An airborne instrument for fast-response, high-precision measurement of tropospheric carbon monoxide (CO) was developed using a vacuum ultraviolet (VUV) resonance fluorescence technique. The excitation radiation is obtained by a DC discharge CO resonance lamp combined with an optical filter for the CO fourth positive band emission around 150 run. The optical filter consists of a VUV monochromator and a crystalline quartz window (< 147-nm cutoff). The crystalline quartz window ensures a sharp: discrimination against wavelengths below 135.7 nm that yield a positive interference from water vapor. Laboratory tests showed that the optical system achieved a precision of 1.1 parts per billion by volume (ppbv) at a CO concentration of 100 ppbv for a 1-s integration period, and the flow system provided a response time (Ile time constant) of similar to2 s. The aircraft measurement campaign Biomass Burning and Lightning Experiment-phase B (BIBLE-B) was conducted between August and September 1999 over the western Pacific and Australia. The flight data obtained during this campaign were used to demonstrate the high precision and fast response of the instrument. An intercomparison of the VUV CO measurement and a gas chromatographic CO measurement was conducted during BIBLE-B. Overall, these two independent measurements showed good agreement, within the experimental uncertainties. C1 Nagoya Univ, Solar Terr Environm Lab, Aichi 4428507, Japan. NOAA, Aeron Lab, Boulder, CO 80303 USA. Natl Space Dev Agcy Japan, Earth Observ Res Ctr, Tokyo, Japan. Univ Tokyo, Adv Sci & Technol Res Ctr, Tokyo 1538904, Japan. Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. RP Takegawa, N (reprint author), Nagoya Univ, Solar Terr Environm Lab, 3-13 Honohara, Aichi 4428507, Japan. EM takegawa@stelab.nagoya-u.ac.jp; kita@atmos.rcast.u-tokyo.ac.jp; kondo@atmos.rcast.u-tokyo.ac.jp; matsumi@stelab.nagoya-u.ac.jp; dparrish@al.noaa.gov; holloway@al.noaa.gov; koike@eps.u-tokyo.ac.jp; yuzom@atmos.rcast.u-tokyo.ac.jp; kawakami@eorc.nasda.go.jp; t_ogawa@eorc.nasda.go.jp RI Parrish, David/E-8957-2010; Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012; Holloway, John/F-9911-2012; Miyazaki, Yuzo/C-6920-2010 OI Parrish, David/0000-0001-6312-2724; Holloway, John/0000-0002-4585-9594; NR 17 TC 14 Z9 14 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 2001 VL 106 IS D20 BP 24237 EP 24244 DI 10.1029/2001JD000459 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 489CG UT WOS:000171974000025 ER PT J AU Cooper, OR Moody, JL Thornberry, TD Town, MS Carroll, MA AF Cooper, OR Moody, JL Thornberry, TD Town, MS Carroll, MA TI PROPHET 1998 meteorological overview and air-mass classification SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID REACTIVE OXIDIZED NITROGEN; NORTH-ATLANTIC OCEAN; CARBON-MONOXIDE; TROPOSPHERIC OZONE; HARVARD FOREST; UNITED-STATES; TRANSPORT; POLLUTION; SITES; CLIMATOLOGY AB The Program for Research on Oxidants: Photochemistry, Emissions, and Transport (PROPHET) summer 1998 measurements intensive was conducted from a tower above a forested site in northern Michigan. This paper provides a brief overview of the meteorological conditions and establishes that the study period was moderately drier and warmer than the climatological mean. The paper also identifies and chemically characterizes the major air mass types influencing the site. Meteorological analyses and back trajectories establish that air mass origin oscillated between relatively clean Canadian regions (except for periods influenced by Canadian forest fires) and regions of greater anthropogenic emissions in the contiguous United States. Higher mixing ratios of ozone, CO, NOx and NOz were generally associated with southerly transport, which occurred 24% of the time. Lower mixing ratios were observed under northerly transport, which occurred 44% of the time. The dominance of northerly transport was due to a stronger than normal Hudson Bay low. The remaining 32% of the time was occupied by,transitional periods between distinct air masses. A positive slope exists between ozone and CO when photochemically aged air masses are selected. However, no meaningful relationship between ozone and CO was observed when northerly and southerly transport periods were considered separately. Comparison to other summertime rural locations suggests that rapid and frequent transitions between air masses of contrasting source regions play an important role in maintaining the 0.3 O-3/CO slope commonly observed in eastern North America. C1 Univ Virginia, Dept Environm Sci, Charlottesville, VA 22904 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. RP Cooper, OR (reprint author), NOAA, Aeron Lab, R-AL4,325 Broadway, Boulder, CO 80303 USA. EM ocooper@al.noaa.gov; jlm8h@virginia.edu; thornber@umich.edu; mstown@u.washington.edu; mcarroll@umich.edu RI Cooper, Owen/H-4875-2013; Thornberry, Troy/H-7106-2013 NR 26 TC 21 Z9 22 U1 0 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 2001 VL 106 IS D20 BP 24289 EP 24299 DI 10.1029/2000JD900409 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 489CG UT WOS:000171974000029 ER PT J AU Miranda, P Pajares, A Guiberteau, F Cumbrera, FL Lawn, BR AF Miranda, P Pajares, A Guiberteau, F Cumbrera, FL Lawn, BR TI Role of flaw statistics in contact fracture of brittle coatings SO ACTA MATERIALIA LA English DT Article DE brittle; coating; flaw statistics ID SILICON-NITRIDE; DAMAGE; CERAMICS; INDENTATION; BILAYERS; MODULUS; MODES; GLASS AB A flaw statistics analysis is here developed to account for systematic differences between experimentally observed and theoretically predicted critical loads for the initiation of contact-induced radial cracks in brittle coatings on compliant substrates. Specific attention is drawn to deviations in critical load (P-R) data from ideal quadratic dependence on coating thickness (d), i.e. P(R)proportional tod(2), especially at low d values. It is postulated that these deviations are attributable to the existence of distributions in flaw size and location, in relation to the bell-shaped tensile stress fields responsible for initiation of the radial cracks at the coating lower surface. A statistics-based expression is derived for the mean values of P-R in terms of flaw density and size distribution. Data from model bilayers consisting of glass plates of different thicknesses d bonded to polycarbonate substrates are used as an illustrative case study. Controlled pre-abrasion flaws are introduced into the lower glass surfaces before joining into the bilayer configuration, to enable a priori characterization of distribution parameters by image analysis. Finite element modelling is used to determine the tensile stress distribution at the coating lower surface. The predicted statistics-based P-R(d) function is shown to fit the data within uncertainty bounds. Implications concerning the continued usefulness of the ideal, P(R)proportional tod(2), relation for designing ceramic coatings for failure resistance are considered. (C) 2001 Acta Materialia Inc. published by Elsevier Science Ltd. All rights reserved. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Extremadura, Fac Ciencias, Dept Fis, E-06071 Badajoz, Spain. Univ Extremadura, Escuela Ingn Ind, Dept Elect & Ingn Electromecan, E-06071 Badajoz, Spain. RP Lawn, BR (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. EM Brian.lawn@nist.gov RI Miranda, Pedro/C-4465-2008; Pajares, Antonia/I-3881-2015 OI Miranda, Pedro/0000-0003-4348-110X; Pajares, Antonia/0000-0002-1086-7586 NR 28 TC 39 Z9 39 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD OCT 26 PY 2001 VL 49 IS 18 BP 3719 EP 3726 DI 10.1016/S1359-6454(01)00280-4 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 485EX UT WOS:000171741500007 ER PT J AU Gilra, N Cohen, C Briber, RM Bauer, BJ Hedden, RC Panagiotopoulos, AZ AF Gilra, N Cohen, C Briber, RM Bauer, BJ Hedden, RC Panagiotopoulos, AZ TI A SANS study of the conformational behavior of linear chains in compressed and uncompressed end-linked elastomers SO MACROMOLECULES LA English DT Article ID MONTE-CARLO SIMULATIONS; DEUTERIUM MAGNETIC-RESONANCE; STRAINED POLYMER NETWORK; SCATTERING; POLY(DIMETHYLSILOXANE); SOLVENT; BLENDS; ORIENTATION; DEFORMATION; DIFFUSION AB Small-angle neutron scattering (SANS) experiments were performed to determine the conformational behavior of unattached deuterated linear poly(dimethylsiloxane) (PDMS) chains of M-n = 51000 g mol(-1) in uncompressed and compressed end-linked protonated PDMS networks with a minimal amount of defects. The networks were prepared from low-polydispersity precursor chains with M-n, = 9900 g mol(-1), 34800 g mol(-1), and 71500 g mol(-1). The samples are hereafter labeled 10K, 35K, and 70K. The mixtures of the 10K network with the linear chains were prepared by cross-linking around the linear chains, while the 35K and 70K network systems were swollen with the linear chains after the network was formed. No significant variation of the radius of gyration of the linear chains was observed as a function of network mesh size, in agreement with recent Monte Carlo simulations. The results from the compressed 35K and 70K networks exhibited excess scattering at small wave vectors, indicating phase segregation, and they could not be quantitatively analyzed. The scattering data from the trapped chains in the compressed 10K networks were fitted well with a Kratky-Porod wormlike chain model, indicating segment alignment consistent with Monte Carlo simulations and deuterium NMR results. C1 Cornell Univ, Sch Chem Engn, Ithaca, NY 14853 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Univ Maryland, Dept Chem Engn, College Pk, MD 20742 USA. RP Cohen, C (reprint author), Cornell Univ, Sch Chem Engn, Ithaca, NY 14853 USA. RI Briber, Robert/A-3588-2012; Panagiotopoulos, Athanassios/K-2955-2014; Hedden, Ronald/M-3909-2014 OI Briber, Robert/0000-0002-8358-5942; Panagiotopoulos, Athanassios/0000-0002-8152-6615; Hedden, Ronald/0000-0003-3571-1403 NR 50 TC 12 Z9 12 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 23 PY 2001 VL 34 IS 22 BP 7773 EP 7782 DI 10.1021/ma010018+ PG 10 WC Polymer Science SC Polymer Science GA 484TP UT WOS:000171705900035 ER PT J AU Harvey, AH AF Harvey, AH TI Comment on "Mixture model description of the T-, P dependence of the refractive index of water" [J. Chem. Phys. 114, 3157 (2001)] SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter ID TEMPERATURE C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Harvey, AH (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. NR 4 TC 1 Z9 1 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 22 PY 2001 VL 115 IS 16 BP 7795 EP 7795 DI 10.1063/1.1406529 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 484YT UT WOS:000171719200052 ER PT J AU Gensemer, SD Jin, DS AF Gensemer, SD Jin, DS TI Transition from collisionless to hydrodynamic behavior in an ultracold Fermi gas SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN TRANSITION; COLLECTIVE OSCILLATIONS; EXCITATIONS; TEMPERATURE; CONDENSATE; TRAPS; MODES AB Relative motion in a two-component, trapped atomic gas provides a sensitive probe of interactions. By studying the lowest frequency excitations of a two-spin-state gas confined in a magnetic trap, we have explored the transition from the collisionless to the hydrodynamic regime. As a function of collision rate, we observe frequency shifts as large as 6% as well as a dramatic, nonmonotonic dependence of the damping rate. The measurements agree qualitatively with expectations for behavior in the collisionless and hydrodynamic limits and are quantitatively compared to a classical kinetic model. C1 Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Quantum Phys Div, Boulder, CO 80309 USA. RP Gensemer, SD (reprint author), Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Quantum Phys Div, Boulder, CO 80309 USA. NR 20 TC 41 Z9 42 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 22 PY 2001 VL 87 IS 17 AR 173201 DI 10.1103/PhysRevLett.87.173201 PG 4 WC Physics, Multidisciplinary SC Physics GA 484UX UT WOS:000171708900020 PM 11690272 ER PT J AU Helmerson, K You, L AF Helmerson, K You, L TI Creating massive entanglement of Bose-Einstein condensed atoms SO PHYSICAL REVIEW LETTERS LA English DT Article ID MULTIPARTICLE ENTANGLEMENT; STATES; SPECTROSCOPY; PHOTOASSOCIATION; COLD AB We propose a direct, coherent coupling scheme that can create massively entangled states of Bose-Einstein condensed atoms. Our idea is based on an effective interaction between two atoms from coherent Raman processes through a (two atom) molecular intermediate state. We compare our scheme with other recent proposals for the generation of massive entanglement of Bose condensed atoms. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. RP Helmerson, K (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Helmerson, Kristian/E-3683-2013 NR 23 TC 89 Z9 95 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 22 PY 2001 VL 87 IS 17 AR 170402 DI 10.1103/PhysRevLett.87.170402 PG 4 WC Physics, Multidisciplinary SC Physics GA 484UX UT WOS:000171708900002 PM 11690254 ER PT J AU Ross, D Bonn, D Posazhennikova, AI Indekeu, JO Meunier, J AF Ross, D Bonn, D Posazhennikova, AI Indekeu, JO Meunier, J TI Crossover from first-order to critical wetting: Short-range tricritical wetting SO PHYSICAL REVIEW LETTERS LA English DT Article ID MEAN-FIELD-THEORY; CRITICAL-BEHAVIOR; CRITICAL-POINTS; 3 DIMENSIONS; ISING-MODEL; TRANSITIONS; FORCES; SYSTEMS; SURFACE; METHANOL AB We study wetting in liquid mixtures of methanol and the n-alkanes. Mixing alkanes of different chain lengths, we can examine the crossover between critical (continuous) and first-order (discontinuous) wetting transitions. Measurements of the film thickness and surface specific heat exponent indicate that for carbon number n between 11 (undecane) and 9 (nonane), there is a crossover from first-order to critical wetting with a tricritical wetting point between an effective alkane carbon number of 9.6 and 10. The observed variation of the specific heat exponent in the tricritical region agrees fairly well with the predictions of a simple mean-field model with only short-range interactions. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Ecole Normale Super, Phys Stat Lab, F-75231 Paris 05, France. Katholieke Univ Leuven, Lab Vaste Stoffys & Magnetisme Lab, B-3001 Louvain, Belgium. RP Ross, D (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8360, Gaithersburg, MD 20899 USA. EM david.ross@nist.gov RI Bonn, Daniel/F-9928-2011 NR 29 TC 17 Z9 17 U1 1 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 22 PY 2001 VL 87 IS 17 AR 176103 DI 10.1103/PhysRevLett.87.176103 PG 4 WC Physics, Multidisciplinary SC Physics GA 484UX UT WOS:000171708900032 PM 11690284 ER PT J AU Wulfmeyer, V Walther, C AF Wulfmeyer, V Walther, C TI Future performance of ground-based and airborne water-vapor differential absorption lidar. I. Overview and theory SO APPLIED OPTICS LA English DT Article ID 720-NM WAVELENGTH REGION; ALEXANDRITE RING LASER; BOUNDARY-LAYER; BACKSCATTER LIDAR; DIAL MEASUREMENTS; RAMAN LIDAR; SYSTEM; TROPOSPHERE; SENSITIVITY; ATMOSPHERE AB The performance of a future advanced water-vapor differential absorption lidar (DIAL) system is discussed. It is shown that the system has to be a direct-detection system operating in the rho sigma tau band of water vapor in the 940-nm wavelength region. The most important features of the DIAL technique are introduced: its clear-air measurement capability, its flexibility, and its simultaneous high resolution and accuracy. It is demonstrated that such a DIAL system can contribute to atmospheric sciences over a large range of scales and over a large variety of humidity conditions. An extended error analysis is performed, and errors (e.g., speckle noise) are included that previously were not been discussed in detail and that become important for certain system designs and measurement conditions. The applicability of the derived equation is investigated by comparisons with real data. Excellent agreement is found. (C) 2001 Optical Society of America. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Atmospher Technol Div, Boulder, CO 80307 USA. RP Wulfmeyer, V (reprint author), Univ Hohenheim, Inst Phys, D-70599 Stuttgart, Germany. EM wulfmeye@uni-hohenheim.de NR 75 TC 44 Z9 45 U1 0 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 2001 VL 40 IS 30 BP 5304 EP 5320 DI 10.1364/AO.40.005304 PG 17 WC Optics SC Optics GA 483BL UT WOS:000171613800004 PM 18364811 ER PT J AU Wulfmeyer, V Walther, C AF Wulfmeyer, V Walther, C TI Future performance of ground-based and airborne water-vapor differential absorption lidar. II. Simulations of the precision of a near-infrared, high-power system SO APPLIED OPTICS LA English DT Article AB Taking into account Poisson, background, amplifier, and speckle noise, we can simulate the precision of water-vapor measurements by using a 10-W average-power differential absorption lidar (DIAL) system. This system is currently under development at Hohenheim University, Germany, and at the American National Center for Atmospheric Research. For operation in the 940-nm region, a large set of measurement situations is described, including configurations that are considered for the first time to the authors' knowledge. They include ultrahigh-resolution measurements in the surface layer (resolutions, 1.5 m and 0.1 s) and vertically pointing measurements (resolutions, 30 m and 1 s) from the ground to 2 km in the atmospheric boundary layer. Even during daytime, the DIAL system will have a measurement range from the ground to the upper troposphere (300 m, 10 min) that can be extended from a mountain site to the lower stratosphere. From the ground, for the first time of which the authors are aware, three-dimensional fields of water vapor in the boundary layer can be investigated within a range of the order of 15 km and with an averaging time of 10 min. From an aircraft, measurements of the atmospheric boundary layer (60 m, 1 s) can be performed from a height of 4 km to the ground. At higher altitudes, up to 18 km, water-vapor profiles can still be obtained from aircraft height level to the ground. When it is being flown either in the free troposphere or in the stratosphere, the system will measure horizontal water-vapor profiles up to 12 km. We are not aware of another remote-sensing technique that provides, simultaneously, such high resolution and accuracy. (C) 2001 Optical Society of America. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Atmospher Technol Div, Boulder, CO 80307 USA. RP Wulfmeyer, V (reprint author), Univ Hohenheim, Inst Phys, D-70599 Stuttgart, Germany. EM wulfmeye@uni-hohenheim.de NR 12 TC 34 Z9 36 U1 2 U2 7 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 2001 VL 40 IS 30 BP 5321 EP 5336 DI 10.1364/AO.40.005321 PG 16 WC Optics SC Optics GA 483BL UT WOS:000171613800005 PM 18364812 ER PT J AU Ricotti, M Gnedin, NY Shull, JM AF Ricotti, M Gnedin, NY Shull, JM TI Feedback from galaxy formation: Production and photodissociation of primordial H-2 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; galaxies : formation; intergalactic medium ID FIRST COSMOLOGICAL OBJECTS; POPULATION-III OBJECTS; LY-ALPHA FOREST; INTERGALACTIC MEDIUM; POWER SPECTRUM; EARLY UNIVERSE; STAR-FORMATION; RADIATION; EQUATION; CLOUDS AB We use one-dimensional radiative transfer simulations to study the evolution of H-2 gas-phase (H- catalyzed) formation and photodissociation regions in the primordial universe. We find a new positive feedback mechanism capable of producing shells of H-2 in the intergalactic medium (IGM), which are optically thick in some Lyman-Werner bands. While these shells exist, this feedback effect is important in reducing the H-2 dissociating background flux and the size of photodissociation spheres around each luminous object. The maximum background opacity of the IGM in the H-2 Lyman-Werner bands is tau (H 2)approximate to1-2 for a relic molecular fraction chi (H 2)=2x10-6, about 6 times greater than that found by Haiman, Abel, & Rees. Therefore, the relic molecular hydrogen can decrease the photodissociation rate by about an order of magnitude. The problem is relevant to the formation of small primordial galaxies with masses M(DM)less than or similar to 10(8) M-circle dot that rely on molecular hydrogen cooling to collapse. Alternatively, the universe may have remained dark for several hundred million years after the birth of the first stars, until galaxies with virial temperature T(vir)greater than or similar to 10(4) K formed. C1 Univ Colorado, Ctr Astrophys & Space Astron, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Univ Colorado, Ctr Astrophys & Space Astron, Dept Astrophys & Planetary Sci, Campus Box 391, Boulder, CO 80309 USA. EM ricotti@casa.colorado.edu; gnedin@casa.colorado.edu; mshull@casa.colorado.edu NR 50 TC 121 Z9 121 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2001 VL 560 IS 2 BP 580 EP 591 DI 10.1086/323051 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 483TM UT WOS:000171652000005 ER PT J AU Shelton, RL Kruk, JW Murphy, EM Andersson, BG Blair, WP Dixon, WV Edelstein, J Fullerton, AW Gry, C Howk, JC Jenkins, EB Linsky, JL Moos, HW Oegerle, WR Oey, MS Roth, KC Sahnow, DJ Sankrit, R Savage, BD Sembach, KR Shull, JM Siegmund, OHW Vidal-Madjar, A Welsh, BY York, DG AF Shelton, RL Kruk, JW Murphy, EM Andersson, BG Blair, WP Dixon, WV Edelstein, J Fullerton, AW Gry, C Howk, JC Jenkins, EB Linsky, JL Moos, HW Oegerle, WR Oey, MS Roth, KC Sahnow, DJ Sankrit, R Savage, BD Sembach, KR Shull, JM Siegmund, OHW Vidal-Madjar, A Welsh, BY York, DG TI Observations of O VI emission from the diffuse interstellar medium SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxy : general; galaxy : halo; ISM : general; ISM : structure; ultraviolet : ISM ID MOLECULAR-HYDROGEN; LOCAL BUBBLE; H-I; BAND SYSTEM; GAS; ABSORPTION; HEMISPHERE; CLOUD; HALO; HOT AB We report the first Far-Ultraviolet Spectroscopic Explorer measurements of diffuse O VI (lambda lambda 1032, 1038) emission from the general diffuse interstellar medium outside of supernova remnants or superbubbles. We observed a 30 " x30 " region of the sky centered at l=315 degrees .0 and b = -41 degrees .3. From the observed intensities (2930 +/- 290 [random] +/- 410 [systematic] and 1790 +/- 260 [random] +/- 250 [systematic] photons cm(-2) s(-1) sr(-1) in lambda lambda 1032 and 1038, respectively), derived equations, and assumptions about the source location, we calculate the intrinsic intensity, electron density, thermal pressure, and emitting depth. The intensities are too large for the emission to originate solely in the Local Bubble. Thus, we conclude that the Galactic thick disk and lower halo also contribute. High-velocity clouds are ruled out because there are none near the pointing direction. The calculated emitting depth is small, indicating that the O VI-bearing gas fills a small volume. The observations can also be used to estimate the cooling rate of the hot interstellar medium and to constrain models. The data also yield the first intensity measurement of the C II 3s S-2(1/2)-2p P-2(3/2) emission line at 1037 Angstrom and place upper limits on the intensities of ultraviolet line emission from C I, CIII, Si II, S III, S IV, S VI, and Fe III. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. European Space Agcy, Div Astrophys, ISO Data Ctr, Madrid 28080, Spain. Astron Spatiale Lab, F-13376 Marseille 12, France. Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Univ Colorado, Dept Astrophys Planetary & Sci, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Lowell Observ, Flagstaff, AZ 86001 USA. Gemini Observ, Hilo, HI 96720 USA. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Inst Astrophys Paris, Paris, France. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Shelton, RL (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RI Oegerle, William/C-9070-2012; Kruk, Jeffrey/G-4047-2012; Howk, Jay/D-2577-2013; Jenkins, Edward/P-5684-2014 OI Jenkins, Edward/0000-0003-1892-4423 NR 59 TC 43 Z9 43 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2001 VL 560 IS 2 BP 730 EP 741 DI 10.1086/322478 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 483TM UT WOS:000171652000021 ER PT J AU Paulson, AJ AF Paulson, AJ TI Biogeochemical removal of Zn and Cd in the Coeur d'Alene River (Idaho, USA), downstream of a mining district SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE acid drainage; zinc; cadmium; biogeochemistry; Coeur d'Alene River; metal-organic complexation ID SURFACE WATERS; HEAVY-METALS; CU; SEDIMENTS; PHYTOPLANKTON; GROUNDWATER; STREAMS; PB AB The conservative biogeochemical behavior of dissolved Zn and Cd in a 17-km, free-flowing reach of the Coeur d'Alene River downstream of a mining district is typical of watersheds in which suspended matter concentrations are low. For watersheds impacted by acid-rock drainage (ARD), low suspended matter concentrations are more likely to be found when acid rock drainage travels through soils because much of the Fe and Al that could form adsorbing surfaces is retained within the soils. In the absence of additional sources of solid substrates, metals can be transported great distances downstream once this Fe- and Al-poor ARD seeps into surface waters. In a 46-km backwater reach of the Coeur d'Alene River, it appears that biological activity increased pH and provided the organic matter solid substrate which removed approximately 50% of the Zn and Cd. Zn removal was partially reversible as pH decreased. These observations reinforce the concept that both inorganic and organic carbon chemistry must be measured if significant advances in our understanding of the attenuation of Zn and Cd from ARD sources are to be made. (C) 2001 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, NEFSC, James J Howard Lab, Highlands, NJ 07732 USA. RP Paulson, AJ (reprint author), NOAA, Natl Marine Fisheries Serv, NEFSC, James J Howard Lab, 74 Magruder Rd, Highlands, NJ 07732 USA. NR 27 TC 11 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD OCT 20 PY 2001 VL 278 IS 1-3 BP 31 EP 44 DI 10.1016/S0048-9697(00)00886-X PG 14 WC Environmental Sciences SC Environmental Sciences & Ecology GA 482EB UT WOS:000171560900004 PM 11669275 ER PT J AU Van Poolen, LJ Holcomb, CD Rainwater, JC AF Van Poolen, LJ Holcomb, CD Rainwater, JC TI Isoplethic method to estimate critical lines for binary fluid mixtures from subcritical vapor-liquid equilibrium: Application to the azeotropic mixtures R32+C3H8 and R125+C3H8 SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID CRITICAL DENSITIES; TEMPERATURE; R32 AB A new, isoplethic method is used to determine critical lines of azeotropic binary fluid mixtures using vapor-liquid equilibrium data including saturated vapor and liquid densities below the lowest critical temperature of the pure components. Thermodynamic paths that access mixture critical lines from this region of the vapor-liquid surface are described by the liquid volume fraction (set at 1/2), fixed overall composition, and pressure. Data along these paths behave like those for a pure fluid and are extrapolated to the critical line by means of simple, pure-fluidlike expressions for the density difference, vapor pressure, and rectilinear diameter for vapor and liquid in equilibrium. The method is tested successfully for an azeotropic mixture for which critical-point estimates can be compared to those in the literature [C3H8 (propane) + C4F8 (perfluorocyclobutane)]. The method is then applied to the two azeotropic mixtures, R32 [CH2F2 (diflouromethane)] + C3H8 (propane) and R125 [C2F5H (pentaflouroethane)] + C3H8 (propane), for which no information is available on the critical line. Analytical expressions for the critical temperature, critical pressure, and critical density are given as functions of the overall composition for these mixtures. The combination of relatively easily measured vapor-liquid equilibrium data along with a simple, thermodynamically correct path to the critical line provides an efficient, relatively simple method for characterizing the vapor-liquid coexistence surfaces for binary mixtures. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Chem Sci & Technol Lab, Boulder, CO 80305 USA. RP Van Poolen, LJ (reprint author), Calvin Coll, Dept Engn, 3201 Burton St SE, Grand Rapids, MI 49546 USA. NR 13 TC 2 Z9 2 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 OCT 17 PY 2001 VL 40 IS 21 BP 4610 EP 4614 DI 10.1021/ie010215x PG 5 WC Engineering, Chemical SC Engineering GA 481NR UT WOS:000171526300015 ER PT J AU McKenzie, RL Johnston, PV Smale, D Bodhaine, BA Madronich, S AF McKenzie, RL Johnston, PV Smale, D Bodhaine, BA Madronich, S TI Altitude effects on UV spectral irradiance deduced from measurements at Lauder, New Zealand, and at Mauna Loa Observatory, Hawaii SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID 3-DIMENSIONAL RADIATIVE-TRANSFER; DISCRETE-ORDINATE-METHOD; MULTIPLE-SCATTERING; CLOUDY ATMOSPHERE; SOLAR-RADIATION; SURFACE ALBEDO; TRANSFER MODEL; OZONE; INVESTIGATE; PROFILES AB Measurements from Lauder, New Zealand, and from the high-altitude Mauna Loa Observatory, Hawaii, are used to determine the altitude effects on spectral UV irradiance and to relate these altitude differences to other factors that influence UV radiation. The measured ratios UVMauna (Loa) / UVLauder are complex functions of both wavelength and solar zenith angle (SZA). Spectrally, the ratios tend to increase toward shorter wavelengths through most of the UV-A region. For small SZA (SZA < similar to 40 degrees) the ratios continue to increase as wavelength decreases throughout the UV-B region. For SZA = 60 degrees a local maximum occurs in the UV-B region. As the SZA increases, this turning point moves to longer wavelengths and its peak value decreases. For SZA > -80 degrees, local minima in the ratios are seen at shorter wavelengths in the UV-B region. For biologically weighted irradiances, the peak ratios occur near SZA = 70 degrees, where UV-A, erythemally weighted UV, UV-B, and DNA-weighted UV irradiances at Mauna Loa Observatory exceeded those at Lauder by similar to 17 %, 26%, 27%, and 29% respectively. The ratios of irradiances at the two altitudes, as functions of SZA and wavelength, were related to differences expected from radiative transfer calculations. For small SZA, modeled and measured ratios agreed within the limits of experimental uncertainty without taking differences in altitude distributions of ozone and temperature into account. However, for larger SZA and shorter wavelengths these profile shapes had a significant effect. In the model calculations, satisfactory agreement with the measurements was achieved only when the contribution from radiation scattered from air or cloud tops below the observation height at Mauna Loa Observatory was included. To model this accurately, a three-dimensional radiative transfer code should be used in conjunction with a topographical model of the surrounding terrain. C1 Natl Inst Water & Atmospher Res, Lauder, New Zealand. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80303 USA. RP McKenzie, RL (reprint author), Natl Inst Water & Atmospher Res, PB 50061 Omakau, Central Otago, New Zealand. EM r.mckenzie@niwa.cri.nz RI Madronich, Sasha/D-3284-2015 OI Madronich, Sasha/0000-0003-0983-1313 NR 27 TC 49 Z9 49 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 16 PY 2001 VL 106 IS D19 BP 22845 EP 22860 DI 10.1029/2001JD900135 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 481UJ UT WOS:000171538600020 ER PT J AU Feingold, G Remer, LA Ramaprasad, J Kaufman, YJ AF Feingold, G Remer, LA Ramaprasad, J Kaufman, YJ TI Analysis of smoke impact on clouds in Brazilian biomass burning regions: An extension of Twomey's approach SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DROPLET NUMBER CONCENTRATIONS; OPTICAL-PROPERTIES; SULFATE AEROSOLS; EFFECTIVE RADIUS; ALBEDO; MICROPHYSICS; CLIMATE; POLLUTION; PARTICLES; RADIATION AB Satellite remote sensing of smoke aerosol-cloud interaction during the recent Smoke, Clouds, and Radiation-Brazil (SCAR-B) experiment is analyzed to explore the factors that determine the magnitude of the cloud response to smoke aerosol. Analysis of 2 years worth of data revealed that the response is greatest in the north of Brazil where aerosol optical depth is smallest, and tends to decrease as one moves southward, and as aerosol optical depth increases. Saturation in this response occurs at an aerosol optical depth of 0.8 in 1987 and 0.4 in 1995. To explore the reasons for this, a framework is developed in which the satellite-measured response can be compared to simple analytical models of this response and to numerical models of smoke aerosol-cloud interaction. Three types of response are identified: (1) cloud droplet concentrations increase with increasing aerosol loading, followed by saturation in the response at high concentrations; (2) as in type 1, followed by increasing droplet concentrations with further increases in aerosol loading. This increase in droplet concentration is due to the suppression of supersaturation by abundant large particles, which prevents the activation of smaller particles. This enables renewed activation of larger particles when smoke loadings exceed some threshold; (3) as in type 1, followed by a decrease in droplet number concentrations with increasing aerosol loading as intense competition for vapor evaporates the smaller droplets. The latter implies an unexpected increase in drop size with increasing smoke loading. The conditions under which each of these responses are expected to occur are discussed. It is shown that although to first-order smoke optical depth is a good proxy for aerosol indirect forcing, under some conditions the size distribution and hygroscopicity can be important factors. We find no evidence that indirect forcing depends on precipitable water vapor. C1 NOAA, ETL, Boulder, CO 80305 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20777 USA. RP Feingold, G (reprint author), NOAA, ETL, 325 Broadway, Boulder, CO 80305 USA. EM graham.feinfold@noaa.gov RI Feingold, Graham/B-6152-2009 NR 38 TC 99 Z9 101 U1 5 U2 16 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 16 PY 2001 VL 106 IS D19 BP 22907 EP 22922 DI 10.1029/2001JD000732 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 481UJ UT WOS:000171538600024 ER PT J AU Tie, X Brasseur, G Emmons, L Horowitz, L Kinnison, D AF Tie, X Brasseur, G Emmons, L Horowitz, L Kinnison, D TI Effects of aerosols on tropospheric oxidants: A global model study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OBSERVATORY PHOTOCHEMISTRY EXPERIMENT; ANTHROPOGENIC SULFATE AEROSOLS; CHEMICAL-TRANSPORT MODEL; SULFURIC-ACID-SOLUTIONS; BLACK CARBON SOOT; HETEROGENEOUS CHEMISTRY; NITRIC-ACID; STRATOSPHERIC OZONE; 3-DIMENSIONAL MODEL; EL-CHICHON AB The global distributions of sulfate and soot particles in the atmosphere are calculated, and the effect of aerosol particles on tropospheric oxidants is studied using a global chemical/transport/ aerosol model. The model is developed in the framework of the National Center for Atmospheric Research (NCAR) global three-dimensional chemical/transport model (Model for Ozone and Related Chemical Tracers (MOZART)). In addition to the gas-phase photochemistry implemented in the MOZART model, the present study also accounts for the formation of sulfate and black carbon aerosols as well as for heterogeneous reactions on particles. The simulated global sulfate aerosol distributions and seasonal variation are compared with observations. The seasonal variation of sulfate aerosols is in agreement with measurements, except in the Arctic region. The calculated vertical profiles of sulfate aerosol agree well with the observations over North America. In the case of black carbon the calculated surface distribution is in fair agreement with observations. The effects of aerosol formation and heterogeneous reactions on the surface of sulfate aerosols are studied. The model calculations show the following: (1) The concentration of H2O2 is reduced when sulfate aerosols are formed due to the reaction Of SO2+ H2O2 in cloud droplets. The gas-phase reaction SO2 + OH converts OH to HO2, but the reduction of OH and enhancement of HO2 are insignificant (< 3%). (2) The heterogeneous reaction of HO2 on the surface of sulfate aerosols produces up to 10% reduction of hydroperoxyl radical (HO2) with an uptake coefficient of 0.2. However, this uptake coefficient could be overestimated, and the results should be regard as an upper limit estimation. (3) The N2O5 reaction on the surface of sulfate aerosols leads to an 80% reduction of NOx at middle to high latitudes during winter. Because ozone production efficiency is low in winter, ozone decreases by only 10% as a result of this reaction. However, during summer the N2O5 reaction reduces NOx by 15% and O-3 by 8-10% at middle to high latitudes. (4) The heterogeneous reaction of CH2O on sulfate aerosols with an upper limit uptake coefficient (gamma = 0.01) leads to an 80 to 90% decrease in CH2O and 8 to 10% reduction of HO2 at middle to high latitudes during winter. Many uncertainties remain in our understanding of heterogeneous chemical processes and in the estimate of kinetic parameters. This model study should therefore be regarded as exploratory and subject to further improvements before final conclusions can be made. C1 Natl Ctr Atmospher Res, Boulder, CO 80303 USA. Princeton Univ, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Tie, X (reprint author), Natl Ctr Atmospher Res, Boulder, CO 80303 USA. RI Horowitz, Larry/D-8048-2014; Emmons, Louisa/R-8922-2016 OI Horowitz, Larry/0000-0002-5886-3314; Emmons, Louisa/0000-0003-2325-6212 NR 91 TC 105 Z9 108 U1 1 U2 24 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 16 PY 2001 VL 106 IS D19 BP 22931 EP 22964 DI 10.1029/2001JD900206 PG 34 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 481UJ UT WOS:000171538600026 ER PT J AU Stroud, CA Roberts, JM Williams, J Goldan, PD Kuster, WC Ryerson, TB Sueper, D Parrish, DD Trainer, M Fehsenfeld, FC Flocke, F Schauffler, SM Stroud, VRF Atlas, E AF Stroud, CA Roberts, JM Williams, J Goldan, PD Kuster, WC Ryerson, TB Sueper, D Parrish, DD Trainer, M Fehsenfeld, FC Flocke, F Schauffler, SM Stroud, VRF Atlas, E TI Alkyl nitrate measurements during STERAO 1996 and NARE 1997: Intercomparison and survey of results SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ABSORPTION CROSS-SECTIONS; STRATOSPHERIC-TROPOSPHERIC EXPERIMENT; MULTIFUNCTIONAL ORGANIC NITRATES; POLLUTED AIR MASSES; ATMOSPHERIC LIFETIMES; CONVECTION EXPERIMENT; HYDROXYL RADICALS; RATE COEFFICIENTS; OZONE PRODUCTION; UNITED-STATES AB Alkyl nitrates were measured over the northeastern plains of Colorado during the Stratospheric Tropospheric Exchange: Radiation, Aerosols and Ozone (STERAO) 1996 campaign and over the North Atlantic during the North Atlantic Regional Experiment (NARE) 1997. Alkyl nitrate measurements were performed by two different laboratories enabling an intercomparison of analytical techniques. A weighted bivariate linear regression analysis of comparable samples (National Oceanic and Atmospheric Administration versus National Center for Atmospheric Research) for the four alkyl nitrates measured by both techniques (2-propyl nitrate, 1-propyl nitrate, 2-butyl nitrate, and 3-pentyl nitrate) suggests there is neither a significant calibration difference nor a systematic offset. The precision of the measurements is indicated by the scatter in the correlations. Good precision is observed for the 2-butyl nitrate measurements (square of the correlation coefficient, R-2=0.90). However, relatively small values of R-2 and relatively large uncertainties in the determination of the slopes and intercepts (2 sigma confidence intervals) for 2-propyl nitrate, 1-propyl nitrate, and 3-pentyl nitrate suggest significant imprecision when compared to ambient mixing ratios for at least one of the measurement techniques. Vertical profiles during NARE 1997 show high levels of alkyl nitrates in well-defined photochemical pollution layers of continental origin. A comparison of alkyl nitrate to hydrocarbon ratios with a sequential reaction scheme model suggests our understanding Of C-4-C-5 alkyl nitrate photochemistry is adequate to reproduce the observations. Air masses with larger ratios of alkyl nitrate to hydrocarbons were observed during NARE 1997 than STERAO 1996, consistent with the NARE 1997 measurements being in the more remote North Atlantic. These results suggest that information related to the photochemical age of an air mass can be derived from alkyl nitrate to hydrocarbon ratios. C1 Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. NOAA, Aeron Lab, Cooperat Inst Res Environm Sci, Boulder, CO 80305 USA. Univ Colorado, Boulder, CO 80309 USA. RP Stroud, CA (reprint author), Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. EM jr@al.noaa.gov RI Roberts, James/A-1082-2009; Kuster, William/E-7421-2010; Parrish, David/E-8957-2010; Trainer, Michael/H-5168-2013; Ryerson, Tom/C-9611-2009; Fehsenfeld, Frederick/I-4876-2013; Atlas, Elliot/J-8171-2015 OI Roberts, James/0000-0002-8485-8172; Kuster, William/0000-0002-8788-8588; Parrish, David/0000-0001-6312-2724; NR 44 TC 12 Z9 12 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 OCT 16 PY 2001 VL 106 IS D19 BP 23043 EP 23053 DI 10.1029/2000JD000003 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 481UJ UT WOS:000171538600032 ER PT J AU Shin, K Rafailovich, MH Sokolov, J Gersappe, D Kim, MW Satija, SK Nguyen, D Xu, D Yang, NL Eisenberg, A AF Shin, K Rafailovich, MH Sokolov, J Gersappe, D Kim, MW Satija, SK Nguyen, D Xu, D Yang, NL Eisenberg, A TI Structures of thin ionomer films in solvent mixtures SO LANGMUIR LA English DT Article ID POLYELECTROLYTE BRUSHES; POLYMER BRUSHES; PREFERENTIAL SOLVATION; NEUTRON REFLECTIVITY; MIXED-SOLVENTS; BEHAVIOR; TRANSITION; DEPENDENCE; INTERFACE AB We have used neutron reflectivity to measure the concentration profiles of polystyrenesulfonated acid (PSSA(x)) films with three different degrees of sulfonation (x = 3.4%, 12.8%, and 27.0%) in water, CCl4, and a mixture of the two solvents. The data show that; except for the x = 3.4% films where CCl4 is a good solvent, the largest degree of swelling occurred in the mixed solvent. Contrast matching the water to the polymer layer enabled us to profile the CCl4. concentration. The results showed that CCl4 and water were mixed within the polymer film in a ratio of 1:2 and 1:4 for 12.8 mol % and 27.0 mol % PSSA, respectively. Self-consistent-field calculations indicated that the number of adsorbed sulfonated blocks scales linearly with the degree of sulfonation. Using the interaction parameters between the PS and SA blocks obtained by fitting to the data in pure solvents, excellent agreement is obtained for the profiles of the polymer and the solvent mixtures for all values of x. C1 SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Korea Adv Inst Sci & Technol, Dept Phys & Adv Mat Engn, Taejon 305701, South Korea. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. CUNY Coll Staten Isl, Dept Chem, Staten Isl, NY 10314 USA. McGill Univ, Dept Chem, Montreal, PQ H3A 2K6, Canada. RP Rafailovich, MH (reprint author), SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. RI Eisenberg, Adi/B-8676-2008; Shin, Kwanwoo /C-4979-2012; Kim, Mahn Won/C-1541-2011; OI Shin, Kwanwoo/0000-0002-7563-8581 NR 30 TC 11 Z9 11 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 16 PY 2001 VL 17 IS 21 BP 6675 EP 6682 DI 10.1021/la001725j PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 482XL UT WOS:000171602500043 ER PT J AU Margolis, SA Mele, T AF Margolis, SA Mele, T TI Systematic bias in the measurement of water in oils by tubular oven evaporation and azeotropic distillation SO ANALYTICAL CHEMISTRY LA English DT Article ID VOLUMETRIC FISCHER,KARL METHODS; MOISTURE AB Water in oil has been measured by tubular oven evaporation and by azeotropic distillation into a coulometric moisture analyzer. The results of these measurements were compared to the results obtained by volumetric titration of water in oil. The volumetric measurements were consistently higher than the measurements made by tubular oven evaporation or azeotropic distillation. A mass balance study was performed by volumetric Karl Fischer titration of the water in the oil that remained in the tubular oven and in the distillation apparatus. This study indicated that measurable amounts of water were not removed after exhaustive evaporation or distillation. The sum of the water removed by distillation from toluene and that remaining in the distillation chamber was equal to the amount of water measured in the oil by the volumetric method. The data are consistent with the existence of an oil-water azeotrope that does not release water upon evaporation at 160 degreesC or upon dissolution in toluene and distillation of the water-toluene azeotrope. These results were obtained for oils varying in viscosity from 8 to 850 m(2)/s, and the amount of water remaining associated with the oil appears to be dependent upon the composition of the oil and the method of analysis. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Margolis, SA (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. NR 19 TC 7 Z9 9 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 2001 VL 73 IS 20 BP 4787 EP 4792 DI 10.1021/ac010086u PG 6 WC Chemistry, Analytical SC Chemistry GA 484NQ UT WOS:000171696800005 PM 11681452 ER PT J AU Salit, ML Turk, GC Lindstrom, AP Butler, TA Beck, CM Norman, B AF Salit, ML Turk, GC Lindstrom, AP Butler, TA Beck, CM Norman, B TI Single-element solution comparisons with a high-performance inductively coupled plasma optical emission spectrometric method SO ANALYTICAL CHEMISTRY LA English DT Article ID INTERNAL STANDARDIZATION AB A solution-based inductively coupled plasma optical emission spectrometric (ICP-OES) method is described for elemental analysis,vith relative expanded uncertainties on the order of 0.1% relative. The single-element determinations of 64 different elements are presented, with aggregate performance results for the method and parameters for the determination of each element. The performance observed is superior to that previously reported for ICP-OES, resulting from a suite of technical strategies that exploit the strengths of contemporary spectrometers, address measurement and sample handling noise sources, and permit rugged operation with small uncertainty. Taken together, these strategies constitute high-performance ICP-OES. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Salit, ML (reprint author), NIST, Chem Sci & Technol Lab, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 17 TC 36 Z9 36 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 2001 VL 73 IS 20 BP 4821 EP 4829 DI 10.1021/ac0155097 PG 9 WC Chemistry, Analytical SC Chemistry GA 484NQ UT WOS:000171696800010 PM 11681457 ER PT J AU Braban, CF Abbatt, JPD Cziczo, DJ AF Braban, CF Abbatt, JPD Cziczo, DJ TI Deliquescence of ammonium sulfate particles at sub-eutectic temperatures SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID METASTABILITY PHASE-DIAGRAMS; ICE FORMATION; AEROSOLS; EFFLORESCENCE; EQUILIBRIUM; NUCLEATION AB To better understand atmospheric aerosol phase transitions under free tropospheric conditions, the behavior of ammonium sulfate (AS) particles mounted on a silicon substrate has been investigated between 229 and 295 K. Experiments were performed in a chamber where water partial pressure and particulate infrared spectra were monitored as the temperature was lowered. Deliquescence experiments at temperatures above the eutectic (254 K) are not new, however results defining deliquescence relative humidity (DRH) at temperatures below the eutectic have been lacking. At sub-eutectic temperatures the system is supersaturated with respect to ice, therefore both deliquescence and ice formation were possible. Within experimental error, deliquescence was observed at the thermodynamically predicted value both above and below the eutectic. The lack of a significant kinetic barrier to deliquescence implies that AS particles could form supercooled solution droplets at high relative humidities, and function as ice nuclei if these droplets homogeneously freeze. C1 Univ Toronto, Dept Chem, Toronto, ON M5S 3H6, Canada. NOAA, Aeron Lab, Boulder, CO 80305 USA. RP Braban, CF (reprint author), Univ Toronto, Dept Chem, 80 St George St, Toronto, ON M5S 3H6, Canada. RI Braban, Christine/J-3225-2012 OI Braban, Christine/0000-0003-4275-0152 NR 17 TC 16 Z9 16 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 2001 VL 28 IS 20 BP 3879 EP 3882 DI 10.1029/2001GL013175 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 482RA UT WOS:000171588000014 ER PT J AU Mayer, DA Molinari, RL Baringer, MON Goni, GJ AF Mayer, DA Molinari, RL Baringer, MON Goni, GJ TI Transition regions and their role in the relationship between sea surface height and subsurface temperature structure in the Atlantic Ocean SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEASONAL VARIABILITY; ANNUAL CYCLE; TOPOGRAPHY AB Expendable bathythermograph (XBT) profiles and TOPEX/Poseidon altimeter data (T/P) are compared for the years 1993 through 1997 to determine how much can be understood about water column variability from XBT's given only sea height anomalies (SHA) from T/P. Our focus is on the annual cycle along two well sampled XBT sections in the Atlantic Ocean from 10 degreesS to 40 degreesN. Regions of transition are identified that separate the mid-latitudes where surface buoyancy fluxes dominate the forcing of sea level, from those in the equatorial region where thermocline effects dominate. Zones of transition occur in the vicinity of troughs where small fluctuations in SHA belie the true nature of water column variability. Here, surface and thermocline variability tend to cancel each other. Thus, the character of SHA in transition regions emphasizes how important direct observations can be in interpreting satellite altimetric observations correctly when both surface and thermocline variability are important but are compensating in nature. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Mayer, DA (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RI Goni, Gustavo/D-2017-2012; Baringer, Molly/D-2277-2012 OI Goni, Gustavo/0000-0001-7093-3170; Baringer, Molly/0000-0002-8503-5194 NR 11 TC 18 Z9 18 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 OCT 15 PY 2001 VL 28 IS 20 BP 3943 EP 3946 DI 10.1029/2001GL013331 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 482RA UT WOS:000171588000030 ER PT J AU Deng, L Payne, MG Hagley, EW AF Deng, L Payne, MG Hagley, EW TI Propagation of light pulse in an ultra-cold atomic vapor: mechanism for the loss of the probe field SO OPTICS COMMUNICATIONS LA English DT Article DE wave propagation; electromagnetically induced transparency; four-level system; group velocity ID GAIN AB We examine the role of nearby hyper-fine levels in a three-level transparency driven system in which a slow group velocity of light propagation is anticipated. In addition to accounting for the significant (> 80%) probe field loss, our theory can accurately model the significant (near 30%) pulse broadening found in two recent experiments. Other excitation schemes for reducing the absorption from nearby levels are discussed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 NIST, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. RP Deng, L (reprint author), NIST, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RI Deng, Lu/B-3997-2012; Hagley, Edward/B-4285-2012 NR 11 TC 14 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD OCT 15 PY 2001 VL 198 IS 1-3 BP 129 EP 133 DI 10.1016/S0030-4018(01)01506-1 PG 5 WC Optics SC Optics GA 482HZ UT WOS:000171571900019 ER PT J AU Agamalian, M Iolin, E Kaiser, H Rehm, C Werner, SA AF Agamalian, M Iolin, E Kaiser, H Rehm, C Werner, SA TI Dynamical neutron-scattering measurements of residual stress in a Si crystal coated with a thin film SO PHYSICAL REVIEW B LA English DT Article ID DIFFRACTION AB The residual stress in a thick Si(111) crystal coated with a 2000 Angstrom thick Ni film was measured at the double-crystal diffractometer at Oak Ridge National Laboratory. The observed asymmetry of the back-face rocking curves and appearance of the garland reflections are related to the ultrasmall deformation strain induced by the Ni film. Relative deformation of the Si crystallographic cells in the vicinity of diffractive surfaces is \ partial derivativeu(z)/partial derivativez \ approximate to1.6.10(-6). The radius of bending is similar to 19 km and the corresponding tension force applied to the Ni film is 90 +/-5 N/m. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Missouri, Columbia, MO 65211 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Agamalian, M (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 10 TC 0 Z9 0 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 OCT 15 PY 2001 VL 64 IS 16 AR 161402 PG 4 WC Physics, Condensed Matter SC Physics GA 487GX UT WOS:000171866400018 ER PT J AU Soininen, JA Shirley, EL AF Soininen, JA Shirley, EL TI Scheme to calculate core hole-electron interactions in solids SO PHYSICAL REVIEW B LA English DT Article ID X-RAY-ABSORPTION; AB-INITIO CALCULATION; NEAR-EDGE STRUCTURE; DYNAMIC STRUCTURE FACTOR; FINE-STRUCTURE; DIELECTRIC MATRICES; OPTICAL-ABSORPTION; BAND-GAPS; SEMICONDUCTORS; INSULATORS AB We introduce a first-principles scheme for calculating a core-hole potential for core-electron excitations. The scheme incorporates atomic and solid-state screening in the description of core excitations in several materials. We compare the results calculated using our scheme to experimental x-ray absorption and inelastic scattering spectra. C1 Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Soininen, JA (reprint author), Univ Helsinki, Dept Phys, POB 9, FIN-00014 Helsinki, Finland. NR 36 TC 83 Z9 84 U1 0 U2 13 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2001 VL 64 IS 16 AR 165112 DI 10.1103/PhysRevB.64.165112 PG 5 WC Physics, Condensed Matter SC Physics GA 487GX UT WOS:000171866400033 ER PT J AU Gillaspy, JD AF Gillaspy, JD TI Highly charged ions SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Review ID HELIUM-LIKE IONS; PARITY NONCONSERVATION; CROSS-SECTIONS; HOLLOW ATOMS; PENNING TRAP; HEAVY-IONS; LAMB SHIFT; PROJECTION LITHOGRAPHY; METAL-SURFACES; BARRIER MODEL AB This paper reviews some of the fundamental properties of highly charged ions, the methods of producing them (with particular emphasis on tabletop devices), and their use as a tool for both basic science and applied technology. Topics discussed include: charge dependence and scaling laws along isoelectronic or isonuclear sequences (for wavefunction size or Bohr radius, ionization energy, dipole transition energy, relativistic fine structure, hyperfine structure, Zeeman effect, Stark effects line intensities, linewidths, strength of parity violation, etc), changes in angular momentum coupling schemes, selection rules, interactions with surfaces, electron-impact ionization, the electron beam ion trap (EBIT), ion accelerators, atomic reference data, cosmic chronometers, laboratory x-ray astrophysics, vacuum polarization, solar flares, ion implantation, ion lithography, ion microprobes (SIMS and x-ray microscope), nuclear fusion diagnostics, nanotechnology, quantum computing, cancer therapy and biotechnology. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Gillaspy, JD (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. NR 159 TC 117 Z9 133 U1 2 U2 20 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD OCT 14 PY 2001 VL 34 IS 19 BP R93 EP R130 DI 10.1088/0953-4075/34/19/201 PG 38 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 491PW UT WOS:000172118300004 ER PT J AU Gharavi, H Reza-Alikhani, H AF Gharavi, H Reza-Alikhani, H TI Pel-recursive motion estimation algorithm SO ELECTRONICS LETTERS LA English DT Article AB A new pel-recursive motion estimation algorithm for video coding applications is presented. The derivation of the algorithm is based on recursive least-squares estimation that minimises the mean-square prediction error. A comparison with the modified steepest-descent gradient estimation technique algorithm shows significant improvement in terms of mean-square prediction error performance. C1 US Dept Commerce, Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Loughborough Univ Technol, Loughborough LE11 3TU, Leics, England. RP Gharavi, H (reprint author), US Dept Commerce, Natl Inst Stand & Technol, 100 Bur DR Stop 8920, Gaithersburg, MD 20899 USA. NR 2 TC 3 Z9 3 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD OCT 11 PY 2001 VL 37 IS 21 BP 1285 EP 1286 DI 10.1049/el:20010879 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 486YL UT WOS:000171846900010 ER PT J AU Grother, P Casasent, D AF Grother, P Casasent, D TI Modulation transfer function measurement method for electrically addressed spatial light modulators SO APPLIED OPTICS LA English DT Article ID LIQUID-CRYSTAL TELEVISION AB The modulation transfer function (MTF), when used with amplitude modulation (m(A)) data, is a vital coherent optical performance measure for a spatial light modulator (SLM). A new image plane amplitude MTF (MTFA) measurement method is presented for electrically addressed SLMs. It involves digital analysis of the output image of a square-wave pattern written onto the SLM. Modulation-level effects are also addressed. Optical laboratory results are presented for two liquid-crystal SLMs. The need to consider amplitude rather than intensity modulation (when coherent optical processing applications are considered) is noted in terms of SLM biasing. (C) 2001 Optical Society of America. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Carnegie Mellon Univ, Dept Elect & Comp Engn, Pittsburgh, PA 15213 USA. RP Grother, P (reprint author), Natl Inst Stand & Technol, Mail Stop 8940, Gaithersburg, MD 20899 USA. EM casasent@ece.cmu.edu NR 8 TC 4 Z9 4 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD OCT 10 PY 2001 VL 40 IS 29 BP 5253 EP 5259 DI 10.1364/AO.40.005253 PG 7 WC Optics SC Optics GA 479LU UT WOS:000171406500013 PM 18364807 ER PT J AU Dizdaroglu, M Burgess, SM Jaruga, P Hazra, TK Rodriguez, H Lloyd, RS AF Dizdaroglu, M Burgess, SM Jaruga, P Hazra, TK Rodriguez, H Lloyd, RS TI Substrate specificity and excision kinetics of Escherichia coli endonuclease VIII (Nei) for modified bases in DNA damaged by free radicals SO BIOCHEMISTRY LA English DT Article ID PURINE LESIONS; FPG PROTEIN; III NTH; GLYCOSYLASE; REPAIR; RADIATION; CYTOSINE; MUTANTS; PRODUCT; ENZYME AB Endonuclease VIII (Nei) is one of three enzymes in Escherichia coli that are involved in base-excision repair of oxidative damage to DNA. We investigated the substrate specificity and excision kinetics of this DNA glycosylase for bases in DNA that have been damaged by free radicals. Two different DNA substrates were prepared by gamma -irradiation of DNA solutions under N2O or air, such that they contained a multiplicity of modified bases. Although previous studies on the substrate specificity of Nei had demonstrated activity on several pyrimidine derivatives, this present study demonstrates excision of additional pyrimidine derivatives and a purine-derived lesion, 4,6-diamino-5-formamidopyrimidine, from DNA containing multiple modified bases. Excision was dependent on enzyme concentration, incubation time, and substrate concentration, and followed Michaelis-Menten kinetics. The kinetic parameters also depended on the identity of the individual modified base being removed. Substrates and excision kinetics of Nei and a naturally arising mutant form involving Leu-90 --> Ser (L90S-Nei) were compared to those of Escherichia coli endonuclease III (Nth), which had previously been determined under experimental conditions similar to those in this study. This comparison showed that Nei and Nth significantly differ from each other in terms of excision rates, although they have common substrates. The present work extends the substrate specificity of Nei and shows the effect of a single mutation in the nei gene on the specificity of Nei. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Univ Texas, Med Branch, Sealy Ctr Environm Hlth & Med, Galveston, TX 77555 USA. Ludwik Rydygier Med Univ, Bydgoszcz, Poland. Univ Texas, Med Branch, Dept Human Biol Chem & Genet, Galveston, TX 77555 USA. Univ Texas, Med Branch, Sealy Ctr Mol Sci, Galveston, TX 77555 USA. RP Dizdaroglu, M (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, 100 Bur Dr,Stop 8311, Gaithersburg, MD 20899 USA. RI Jaruga, Pawel/M-4378-2015 FU NIEHS NIH HHS [ES04091, ES06676] NR 31 TC 36 Z9 36 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 9 PY 2001 VL 40 IS 40 BP 12150 EP 12156 DI 10.1021/bi015552o PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 481CV UT WOS:000171503100019 PM 11580290 ER PT J AU Kim, G Han, CC Libera, M Jackson, CL AF Kim, G Han, CC Libera, M Jackson, CL TI Crystallization within melt ordered semicrystalline block copolymers: Exploring the coexistence of microphase-separated and spherulitic morphologies SO MACROMOLECULES LA English DT Article ID POLY(EPSILON-CAPROLACTONE) C BLOCK; EPSILON-CAPROLACTONE; DIBLOCK COPOLYMERS; TRIBLOCK COPOLYMERS; SPECIMEN THICKNESS; POLYBUTADIENE B; POLYSTYRENE S; THERMODYNAMICS; BUTADIENE; POLYMER AB The crystalline and microphase-separated morphology of semicrystalline block copolymers are compared in bulk (0.5-1 mm) and thin films (5-0 mum), as characterized by transmission electron microscopy (TEM) and polarized light microscopy (PLM). Bulk films of a triblock copolymer of polystyrene, polybutadiene, and polycaprolactone, (PS)(0.35)(PB)(0.15)(PCL)(0.5), where the subscripts denote the mass fraction, show a lamellar-cylindrical microphase-separated morphology with a lamellar repeat of congruent to 62 nm, as observed by TEM. Bulk films of a diblock copolymer consisting of (PB)(0.2)(PCL)(0.8) show an imperfect cylindrical microphase-separated structure by TEM coexisting with crystalline lamellae of PCL. For both bulk specimens, the PLM shows a speckle pattern of birefringence that confirms the PCL is crystallized within the microphase-separated structure, but no large-scale spherulites are observed by PLM. The microstructure in the as-cast thin films (5-10 mum) by TEM is lamellar-cylindrical for the triblock copolymer and cylindrical for the diblock copolymer, as described above for the bulk specimens. Upon thermal treatment of these thin films, large and well-defined PCL spherulites are observed by PLM for both block copolymers. TEM of the thermally treated triblock copolymer thin films shows that, after the formation of spherulites, the microphase structure is no longer lamellar-cylindrical but entirely dominated by PCL lamellar crystals. In contrast, TEM of the thermally treated diblock copolymer thin films shows that the PCL lamellar crystals coexist with the PB microphase-separated cylinders after the formation of PCL spherulites. Bulk specimens could not be induced to form spherulites under similar thermal treatment conditions. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Jackson, CL (reprint author), 1731 Supplee Rd, Lansdale, PA 19446 USA. NR 39 TC 31 Z9 31 U1 2 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 9 PY 2001 VL 34 IS 21 BP 7336 EP 7342 DI 10.1021/ma002004u PG 7 WC Polymer Science SC Polymer Science GA 479CL UT WOS:000171386300019 ER PT J AU Mountain, RD Hubbard, JB Meuse, CW Simmons, V AF Mountain, RD Hubbard, JB Meuse, CW Simmons, V TI Molecular dynamics study of partial monolayer ordering of chain molecules SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID COMPUTER-SIMULATION AB We present the results of a molecular dynamics study of a partial monolayer of self-assembled octadecanethiol molecules. The correlations between various statistical measures of surface induced chain ordering are examined. These include the density profile, chain morphology, tilt angle distributions, and gauche defect distributions. Particular attention is focused on the significance of the strength of the alkane chain surface interaction, as well as the role of temperature, on the type and degree of disorder which we observe. Our simulations are in accord with experimental evidence which indicates that the quality, in the sense of reproducibility in the laboratory, of dense films increases as the coupling of the chain molecules with the surface decreases. We believe that our findings have general implications for the establishment of experimental protocols for self-assembled surface films of organic molecules with varying degrees of prescribed disorder. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Mountain, RD (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 100 Bur Dr Stop 8380, Gaithersburg, MD 20899 USA. NR 11 TC 6 Z9 6 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 4 PY 2001 VL 105 IS 39 BP 9503 EP 9508 DI 10.1021/jp012193y PG 6 WC Chemistry, Physical SC Chemistry GA 479JG UT WOS:000171400800015 ER PT J AU Blanksby, SJ Ramond, TM Davico, GE Nimlos, MR Kato, S Bierbaum, VM Lineberger, WC Ellison, GB Okumura, M AF Blanksby, SJ Ramond, TM Davico, GE Nimlos, MR Kato, S Bierbaum, VM Lineberger, WC Ellison, GB Okumura, M TI Negative-ion photoelectron spectroscopy, gas-phase acidity, and thermochemistry of the peroxyl radicals CH3OO and CH3CH2OO SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID BOND-DISSOCIATION ENERGIES; SET MODEL CHEMISTRY; ABINITIO CALCULATIONS; REVERSIBLE CH3O2; AB-INITIO; KINETICS; ALKYL; OH; ALKYLPEROXY; PHOTOLYSIS AB Methyl, methyl-d(3), and ethyl hydroperoxide anions (CH3OO-, CD3OO-, and CH3CH2OO-) have been prepared by deprotonation of their respective hydroperoxides in a stream of helium buffer, gas. Photodetachment with 364 nm (3.408 eV) radiation was used to measure the adiabatic electron affinities: EA[CH3OO, (X) over tilde (2)A"] = 1.161 +/- 0.005 eV, EA[CD3OO, (X) over tilde (2)A"] = 1.154 +/- 0.004 eV, and EA[CH3CH2OO, (X) over tilde (2)A"] = 1.186 +/- 0.004 eV. The photoelectron spectra yield values for the term energies: DeltaE((X) over tilde 2A"-(A) over tilde 2A')[CH3OO] = 0.914 +/- 0.005 eV, DeltaE((X) over tilde (2)A"-(A) over tilde 2A') [CD3OO] = 0.913 +/- 0.004 eV, and DeltaE((X) over tilde (2)A"-(A) over tilde (2)A')[CH3CH2OO] = 0.938 +/- 0.004 eV. A localized RO-O stretching mode was observed near 1100 cm(-1) for the ground state of all three radicals, and low-frequency R-O-O bending modes are also reported. Proton-transfer kinetics of the hydroperoxides have been measured in a tandem flowing afterglow-selected ion flow tube k(FA-SIFT) to determine the gas-phase acidity of the parent hydroperoxides: Delta (acid)G(298)(CH3OOH) = 367.6 +/- 0.7 kcal mol(-1), Delta (acid)G(298)(CD3OOH) = 367.9 +/- 0.9 kcal mol(-1), and Delta (acid)G(298)(CH3CH2OOH) = 363.9 +/- 2.0 kcal mol(-1). From these acidities we have derived the enthalpies of deprotonation: Delta H-acid(298)(CH3OOH) = 374.6 +/- 1.0 kcal mol(-1), Delta H-acid(298)(CD3OOH) = 374.9 +/- 1.1 kcal mol(-1), and Delta H-acid(298)(CH2CH3OOH) = 371.0 +/- 2.2 kcal mol(-1). Use of the negative-ion acidity/EA cycle provides the ROO-H bond enthalpies: DH298(CH3OO-H) 87.8 +/- 1.0 kcal mol(-1), DH298(CD3OO-H) = 87.9 +/- 1.1 kcal mol(-1), and DH298(CH3CH2OO-H) = 84.8 +/- 2.2 kcal mol(-1). We review the thermochemistry of the peroxyl radicals, CH3OO and CH3CH2OO. Using experimental bond enthalpies, DH298(ROO-H), and CBS/APNO ab initio electronic structure calculations for the energies of the corresponding hydroperoxides, we derive the heats of formation of the peroxyl radicals. The "electron affinity/acidity/CBS" cycle yields Delta H-f(298)[CH3OO] = 4.8 +/- 1.2 kcal mol(-1) and Delta H-f(298)[CH3CH2OO] = -6.8 +/- 2.3 kcal mol(-1). C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. CALTECH, Dept Chem, Pasadena, CA 91125 USA. RP Bierbaum, VM (reprint author), Univ Colorado, Dept Chem & Biochem, Campus Box 215, Boulder, CO 80309 USA. RI Blanksby, Stephen/C-8388-2013; Okumura, Mitchio/I-3326-2013 OI Blanksby, Stephen/0000-0002-8560-756X; Okumura, Mitchio/0000-0001-6874-1137 NR 81 TC 107 Z9 107 U1 3 U2 46 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 3 PY 2001 VL 123 IS 39 BP 9585 EP 9596 DI 10.1021/ja010942j PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA 479MH UT WOS:000171407800011 PM 11572679 ER PT J AU Jakupciak, JP O'Connell, CD Atha, DA Richie, KL AF Jakupciak, JP O'Connell, CD Atha, DA Richie, KL TI Standardization of PCR amplification for fragile X trinucleotide repeat measurements. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 NIST, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 2001 VL 69 IS 4 SU 1 MA 1451 BP 430 EP 430 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 483RD UT WOS:000171648901451 ER PT J AU Vallone, PM Butler, JM AF Vallone, PM Butler, JM TI Detection of single nucleotide polymorphisms by MALDI-TOF Mass Spectrometry. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Natl Inst Stand Technol, Div Biotechnol, Gaithersburg, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 2001 VL 69 IS 4 SU 1 MA 1691 BP 470 EP 470 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 483RD UT WOS:000171648901691 ER PT J AU Helmerson, K Kishore, R Phillips, WD Weetall, HH AF Helmerson, K Kishore, R Phillips, WD Weetall, HH TI An optical tweezers-based immunosensor for detection of femtomoles-per-liter concentrations of antigens SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT National Symposium on Biomolecular Electronics-Interfacing Physics and Chemistry with Biology (BEIPCB) CY SEP 16-17, 1999 CL NATL PHYS LAB, NEW DELHI, INDIA SP Council Sci & Ind Res, Indian Natl Sci Acad HO NATL PHYS LAB DE optical tweezers; laser trap; immunosensor; assay; antigen; antibody; BSA ID MANIPULATION AB We used optical tweezers-optical trapping with focused laser beams-to pull microspheres coated with antigens off of an antibody-coated surface. Using this technique, we could quantify the force required to separate antigen to antibody bonds. At very low surface density of antigen, we were able to detect the single antigen to antibody binding. The force required to break the antigen-antibody bonds and pull the microsphere off the surface was shown to increase monotonically with increasing surface density of antigens. Using the force determination as a transducer, we were able to detect concentrations of free antigens in solution as small as 10(-15) mol/L in a competitive binding assay. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Helmerson, K (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Helmerson, Kristian/E-3683-2013 NR 6 TC 7 Z9 7 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD OCT-DEC PY 2001 VL 96 IS 1-3 BP 205 EP 213 DI 10.1385/ABAB:96:1-3:205 PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA 503UW UT WOS:000172820600021 PM 11783887 ER PT J AU Downing, SL Prentice, EF Frazier, RW Simonson, JE Nunnallee, EP AF Downing, SL Prentice, EF Frazier, RW Simonson, JE Nunnallee, EP TI Technology developed for diverting passive integrated transponder (PIT) tagged fish at hydroelectric dams in the Columbia River Basin SO AQUACULTURAL ENGINEERING LA English DT Article DE fish diversion gates; fish diverter; passive integrated transponder tag; separation by code ID SNAKE RIVER; SALMON; SURVIVAL AB Data collected on juvenile salmonids tagged with passive integrated transponder (PIT) tags as they migrate seaward through the Columbia River Basin provide fisheries managers and resource agencies with valuable information to evaluate the effectiveness of current management actions and restoration strategies. The development of new technology to route PIT-tagged fish through multiple alternative pathways as they pass through the interrogation systems at the fish bypass/monitoring facilities at hydroelectric dams provides another valuable real-time tool to monitor and evaluate the migration, passage, and survival of PIT-tagged juvenile salmonids in the basin. The authors describe the current computer program and gate-control technology for routing fish, and provide detailed descriptions of three new types of fish-diversion gates. The comparative advantages and disadvantages of each gate are discussed. The prototype of a fourth diversion gate, with only one moving part, is also described. (C) 2001 Elsevier Science B.V. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Downing, SL (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 24 TC 19 Z9 22 U1 1 U2 7 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 OCT PY 2001 VL 25 IS 3 BP 149 EP 164 DI 10.1016/S0144-8609(01)00079-6 PG 16 WC Agricultural Engineering; Fisheries SC Agriculture; Fisheries GA 474MT UT WOS:000171111600002 ER PT J AU Johnson, KE Kobulnicky, HA Massey, P Conti, PS AF Johnson, KE Kobulnicky, HA Massey, P Conti, PS TI A sample of clusters of extragalactic ultracompact HII regions SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (M33, NGC 253, NGC 6946); galaxies : ISM; galaxies : star clusters; HII regions; radio continuum : galaxies; stars : formation ID H-II REGIONS; SUPERNOVA-REMNANTS; RADIO-SOURCES; GALAXY NGC-6946; NEARBY GALAXIES; STAR FORMATION; MASSIVE STARS; M33; NGC-253; RESOLUTION AB We report on the detection of optically thick free-free radio sources in the galaxies M33, NGC 253, and NGC 6946 using data in the literature. We interpret these sources as being young embedded star birth regions that are likely to be clusters of ultracompact H II regions. All 35 of the sources presented in this article have positive radio spectral indices (alpha > 0 for S-v proportional to v(alpha)), suggesting an optically thick thermal bremsstrahlung origin from the H II region surrounding the hot stars. The estimated emission measures for these sources are EM6cm greater than or similar to 10(8) cm(-6) pc, and energy requirements indicate that the sources in our sample have a range of a few to similar to 560 O7 V star equivalents powering their H II regions. Assuming a Salpeter initial mass function with lower and upper mass cutoffs of 1 and 100 M., respectively, this range in N-Lyc corresponds to integrated stellar masses of 0.1-60 x 10(3) M. For roughly half of the sources in our sample there is no obvious optical counterpart, which gives further support for their deeply embedded nature; for most of the remaining sources, the correspondence to an optical source is insecure owing to relative astrometric uncertainty. Their luminosities and radio spectral energy distributions are consistent with H II regions modeled as spheres of plasma with electron densities from n(e) similar to1.5 x 10(3) to similar to1.5 x 10(4) cm(-3) and radii of similar to1-7 pc. Because of the high densities required to Dt the data, we suggest that the less luminous of these sources are extragalactic ultracompact H II region complexes, those of intermediate luminosity are similar to W49 in the Galaxy, and the brightest will be counterparts to 30 Doradus when they emerge from their birth material. These objects constitute the lower mass range of extragalactic "ultradense H II regions," which we argue are the youngest stages of massive star cluster formation yet observed. The sample presented in this paper is beginning to fill in the continuum of objects between small associations of ultracompact H II regions and the analogous massive extra-galactic clusters that may evolve into globular clusters. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Lowell Observ, Flagstaff, AZ 86001 USA. RP Johnson, KE (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. OI Massey, Philip/0000-0001-6563-7828 NR 52 TC 39 Z9 39 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2001 VL 559 IS 2 BP 864 EP 877 DI 10.1086/322335 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 480BD UT WOS:000171439800025 ER PT J AU Misakian, M Kasianowicz, JJ Robertson, B Petersons, O AF Misakian, M Kasianowicz, JJ Robertson, B Petersons, O TI Frequency response of alternating currents through the Staphylococcus aureus alpha-hemolysin ion channel SO BIOELECTROMAGNETICS LA English DT Article DE electrical properties; membrane; ion transport; planar membranes; equivalent circuit ID AC-IMPEDANCE; MEMBRANES; TOXIN; PORE; TRANSPORT; DYNAMICS; SITES AB Alternating currents were measured through transmembrane ion channels formed by Staphylococcus aureus a-hemolysin proteins in planar bilayer membranes as part of an investigation to determine the channel's frequency response and the appropriateness of an equivalent circuit commonly used to model electrical interactions at the surface of cells. The experimental approach includes a novel method for separating the alternating current through one or more channels, which is conductive in nature, from the capacitively coupled current through the membrane. Separation of the conductive and capacitive alternating currents made it possible to measure the frequency response of the oc-hemolysin channels. The results of the study are consistent with an equivalent circuit of a membrane capacitor in parallel with one or more channel resistors over the frequency range 30-120 Hz. The possible usefulness of frequency response data for ion channels in cell membranes during investigations of biological effects of time-varying magnetic fields is briefly discussed. Published 2001 Wiley-Liss, Inc.(dagger) C1 NIST, Div Elect, Gaithersburg, MD 20899 USA. NIST, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Misakian, M (reprint author), NIST, Div Elect, 100 Bur Dr,MS 8113, Gaithersburg, MD 20899 USA. NR 22 TC 4 Z9 4 U1 0 U2 7 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0197-8462 J9 BIOELECTROMAGNETICS JI Bioelectromagnetics PD OCT PY 2001 VL 22 IS 7 BP 487 EP 493 PG 7 WC Biology; Biophysics SC Life Sciences & Biomedicine - Other Topics; Biophysics GA 476UF UT WOS:000171246600005 PM 11568934 ER PT J AU Mueller, HJ Hirthe, RW AF Mueller, HJ Hirthe, RW TI Electrochemical characterization and immersion corrosion of a consolidated silver dental biomaterial SO BIOMATERIALS LA English DT Article DE silver particle consolidation; artificial saliva; corrosion; electrochemical polarization; impedance spectroscopy ID IMPEDANCE; SPECTROSCOPY; AMALGAMS; MODEL AB A consolidated silver (CS) material, an alternative to dental amalgam, was studied for corrosion. Chemically precipitated silver particles were acid activated and pressure consolidated to a volume porosity of 25%. In selected tests comparisons were made between CS and melted and cast silver particles (MS), silver with a known mass fraction purity of 99.998% (FS), a silver-palladium alloy (SP), and a dispersed-phase amalgam (DA). Fusayama artificial saliva was used with controlled variations in pH, sulfide content, mucin content, and absorbed oxygen content. Electrochemical polarization, electrochemical impedance spectroscopy, and immersion methods were used. Results revealed differences in the zero current potentials E(I = 0) from forward polarization between CS and MS (or FS) in deaerated solution, By superposition of the cathodic polarization curves, the area for CS was increased by 7.3 times and was enclosed within an outer shell of material 5.5 mum thick. Polarization resistance was significantly the highest for SP, followed in order by MS (or FS) and CS or DA. With scanning electron microscopy, CS was shown to be significantly more susceptible than MS to long-term immersion corrosion. The modeled equivalent electrical circuits for CS and DA involved a double layer capacitance, a charge transfer resistance, and an element attributed to adsorption. The active pore depth for CS from the transmission line model for porous solids revealed satisfactory agreement with polarization results. It is concluded that the corrosion susceptibility of CS in Fusayama solution, while similar to that for DA, is greater than it is for MS. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. Marquette Univ, Coll Engn, Milwaukee, WI 53233 USA. RP Mueller, HJ (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [P50 DE 09322] NR 24 TC 8 Z9 9 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-9612 J9 BIOMATERIALS JI Biomaterials PD OCT PY 2001 VL 22 IS 19 BP 2635 EP 2646 DI 10.1016/S0142-9612(01)00004-7 PG 12 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 463HE UT WOS:000170470400007 PM 11519783 ER PT J AU Tsai, AM Udovic, TJ Neumann, DA AF Tsai, AM Udovic, TJ Neumann, DA TI The inverse relationship between protein dynamics and thermal stability SO BIOPHYSICAL JOURNAL LA English DT Article ID INELASTIC NEUTRON-SCATTERING; LYOPHILIZED BOVINE SOMATOTROPIN; INDUCED DENATURATION; MOLECULAR MOTIONS; TEMPERATURE; DEHYDROGENASE; FLEXIBILITY; DEPENDENCE; TRANSITION; LYSOZYME AB Protein powders that are dehydrated or mixed with a glassy compound are known to have improved thermal stability. We present elastic and quasielastic neutron scattering measurements of the global dynamics of lysozyme and ribonuclease A powders. In the absence of solvation water, both protein powders exhibit largely harmonic motions on the timescale of the measurements. Upon partial hydration, quasielastic scattering indicative of relaxational processes appears at sufficiently high temperature. When the scattering spectrum are analyzed with the Kohlrausch-Williams-Watts formalism, the exponent beta decreases with increasing temperature, suggesting that multiple relaxation modes are emerging. When lysozyme was mixed with glycerol, its beta values were higher than the hydrated sample at comparable temperatures, reflecting the viscosity and stabilizing effects of glycerol. C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Tsai, AM (reprint author), NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. NR 24 TC 58 Z9 58 U1 1 U2 12 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD OCT PY 2001 VL 81 IS 4 BP 2339 EP 2343 PG 5 WC Biophysics SC Biophysics GA 476AY UT WOS:000171205100046 PM 11566803 ER PT J AU Mearns, A Watabayashi, G Lankford, J AF Mearns, A Watabayashi, G Lankford, J TI Dispersing oil near shore in the California Current region SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article ID HERRING CLUPEA-PALLASI; WEATHERED CRUDE-OIL; PETROLEUM-HYDROCARBONS; AQUATIC TOXICITY; SPILL RESPONSE; FISH EMBRYOS; SENSITIVITY; MORTALITY; EXPOSURE AB Mathematical models were used to develop scenarios for evaluating alternative nearshore responses to oil spills. including the use of chemical dispersants. The scenarios were used in ecological risk assessment (ERA) workshops designed to help fisheries, wildlife, and resource managers determine whether they would support preapproving the use of dispersants. Resource managers proposed a worst-case spill scenario for the Gulf of the Farallones. Models were used to compare five options-no response, mechanical, burning, and two levels of dispersants showing the trajectories, fate, and concentration of oil in surface slicks and dispersed Oil plumes. Participating biologists used current data on dispersant and dispersed oil toxicity to develop consensus-based toxicity guidelines. During the first several hours following dispersal, the simulated dispersed oil concentrations exceeded guidelines for early life-history stages of fishes and zooplankton; adult fish and crustaceans were at risk for two hours. The benefits and risks to fishes, seabirds. cetaceans, pinnipeds, sea otters, and shoreline resources (marshes, kelp beds, and protected areas) were compared for the five response options. Dispersants substantially reduced the amount of both floating and stranded oil relative to the other options. Furthermore. the higher dispersant level (85%) removed more oil than the lower level (35%). Risk assessments so far indicate that chemical dispersion can reduce the overall ecological effects of a nearshore oil spill. The final decision to preapprove dispersant use along the Pacific Coast will still require input from the political. social. and economic sectors. C1 NOAA, Hazardous Mat Response Div, Seattle, WA 98115 USA. RP Mearns, A (reprint author), NOAA, Hazardous Mat Response Div, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 53 TC 1 Z9 1 U1 1 U2 6 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 USA SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 2001 VL 42 BP 97 EP 109 PG 13 WC Fisheries SC Fisheries GA 545KM UT WOS:000175216400010 ER PT J AU Moser, HG Charter, RL Watson, W Ambrose, DA Hill, KT Smith, PE Butler, JL Sandknop, EM Charter, SR AF Moser, HG Charter, RL Watson, W Ambrose, DA Hill, KT Smith, PE Butler, JL Sandknop, EM Charter, SR TI The CalCOFI ichthyoplankton time series: Potential contributions to the management of rocky-shore fishes SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article ID FECUNDITY REDUCTION METHOD; SOUTHERN CALIFORNIA BIGHT; LARVAE; ABUNDANCE; NEARSHORE; BIOMASS; PATTERN; WATERS AB Harvest of nearshore fishes off California, particularly species in the recently expanded live-fish fishery, has impacted many of these stocks. Important taxa are cabezon, sheephead, lingcod, greenlings, and the rockfishes included in the subgenus Pteropodus. Life-history information and fishery-independent abundance indices are badly needed for the development of management strategies for these stocks. The California Cooperative Oceanic Fisheries Investigations (CalCOFI) surveys can provide indices of abundance for larval stages of many species. including cabezon, sheephead, kelp and sand basses, lingcod. and several species of rockfishes. This paper presents. as examples, data on the distribution and abundance Of cabezon, sheephead. and Paralabrax (kelp and sand bass) larvae in the Southern California Bight region and compares these with data from other nearshore ichthyoplankton surveys conducted in the region. Trends ill landings for cabezon generally match trends in CalCOFI larval indices. supporting use of the larval catch data as fishery-independent abundance indices. The principal recommendation for improving nearshore larval time series is to reestablish plankton tow station, on CalCOFI Survey cruises off central California, where standard plankton tows have not been taken since the survey area was reduced in 1985. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Moser, HG (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, POB 271, La Jolla, CA 92038 USA. NR 39 TC 21 Z9 21 U1 1 U2 5 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 USA SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 2001 VL 42 BP 112 EP 128 PG 17 WC Fisheries SC Fisheries GA 545KM UT WOS:000175216400011 ER PT J AU Johnson, KA Yoklavich, MM Cailliet, GM AF Johnson, KA Yoklavich, MM Cailliet, GM TI Recruitment of three species of juvenile rockfish (Sebastes spp.) on soft benthic habitat in Monterey Bay, California SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article ID GENUS SEBASTES; PELAGIC JUVENILES; REEF FISHES; DEEP-REEF; GROWTH; LARVAL; ECOLOGY; DISTRIBUTIONS; ASSOCIATIONS; CIRCULATION AB A number of ecologically and economically important species of rockfishes recruited to soft benthic habitats in Monterey Bay, California, during 1995-96. Sebastes elongatus, S. saxicola, and S. levis were the most abundant and, although caught throughout the depth range (40-100 in) of our survey, had highest densities from 60 to 100 in. Densities of S. elongatus and S. saxicola were greater than that of S. levis. Peak settlement followed ocean upwelling. Size-frequency analysis indicated that, once settled, juvenile rockfish ontogenetically moved toward adult depths. Growth rates ranged from 0.17 to 0.32 mm/d, with growth declining during months of highest sea-surface temperature. Peaks in distribution of back-calculated birthdates corresponded with periods of increased upwelling. Significant emigration from the sampling area occurred during the onset of winter storms. C1 Moss Landing Marine Labs, Moss Landing, CA 95039 USA. RP Johnson, KA (reprint author), Natl Marine Fisheries Serv, Off Habitat Conservat, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 58 TC 12 Z9 12 U1 1 U2 4 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 USA SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 2001 VL 42 BP 153 EP 166 PG 14 WC Fisheries SC Fisheries GA 545KM UT WOS:000175216400014 ER PT J AU Kahler, TH Roni, P Quinn, TP AF Kahler, TH Roni, P Quinn, TP TI Summer movement and growth of juvenile anadromous salmonids in small western Washington streams SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID COHO SALMON; CUTTHROAT TROUT; ONCORHYNCHUS-KISUTCH; RESTRICTED MOVEMENT; BRITISH-COLUMBIA; BROOK TROUT; BROWN TROUT; HABITAT USE; BEHAVIOR; CREEK AB Movements of juvenile coho salmon (Oncorhynchus kisutch), cutthroat trout (Oncorhynchus clarki clarki), and steelhead trout (Oncorhynchus mykiss) were studied by observations and recapture of marked individuals in three western Washington streams to test the hypotheses that few fish would move, downstream movement would predominate, movers would be initially smaller and grow slower after movement than residents, and habitat quality would influence movement. Contrary to predictions, from 28 to 60% of marked fish moved at least one habitat unit, and immigration of unmarked fish also indicated considerable movement. Upstream movement predominated but the stream with the step-pool/cascade channel type had fewer upstream movers and greater distances moved downstream. Coho movers were not smaller than nonmovers, as predicted based on assumptions that movement results from competitive exclusion. Habitat units that coho left were smaller and shallower but lower in density than units where coho remained. Thus, movement is a common phenomenon rather than an aberration, and may reflect habitat choice rather than territorial eviction. Moreover, movers grew faster than nonmovers, so the "mobile fraction" of the population was not composed of competitively inferior fish but rather individuals that thrived. The phenomenon of small-scale habitat- and growth-related movements should be considered when planning and interpreting studies of juvenile salmonid ecology in streams. C1 Watershed Co, Kirkland, WA 98195 USA. Univ Washington, Sch Aquat & Fishery Sci, Seattle, WA 98195 USA. Natl Marine Fisheries Serv, Seattle, WA 98112 USA. RP Kahler, TH (reprint author), Watershed Co, 1410 Market St, Kirkland, WA 98195 USA. NR 39 TC 85 Z9 89 U1 3 U2 19 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 OCT PY 2001 VL 58 IS 10 BP 1947 EP 1956 DI 10.1139/cjfas-58-10-1947 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 481LE UT WOS:000171520100005 ER PT J AU Hobday, AJ Boehlert, GW AF Hobday, AJ Boehlert, GW TI The role of coastal ocean variation in spatial and temporal patterns in survival and size of coho salmon (Oncorhynchus kisutch) SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID NORTH PACIFIC-OCEAN; MARINE SURVIVAL; BRITISH-COLUMBIA; NERKA STOCKS; FRESH-WATER; CLIMATE; SEA; SHIFTS; FISH; TRENDS AB Interannual and decadal variability in ocean survival of salmon are well known, but the mechanisms through which environmental variability exerts its effects are poorly understood. Data on hatchery-reared coho salmon (Oncorhynchus kisutch) from individual releases (1973-1998) along the species' entire North American range were analyzed to provide information on survival and size. Three geographic regions (north of Vancouver Island, Puget Sound and Strait of Georgia, and the outer coast south of the tip of Vancouver Island) showed coherent trends in survival and size of returning fish. Within each region, multivariate nonlinear models were used to relate coho survival and final size to spatially and temporally tailored environmental variables at time periods of release, jack return, and adult return. The most important environmental variable, as indicated by the highest amount of variance explained, was a calculated proxy for mixed-layer depth, followed by sea level. In all regions, survival and adult size were most influenced by environmental conditions at the release time. A shallow mixed layer was associated with increased survival and decreased size in all regions. Improved understanding of the relationship between environmental conditions and size and survival of coho salmon provides insight into production patterns in the coastal ocean. C1 CSIRO, Hobart, Tas 7001, Australia. NOAA, NMFS, SW Fisheries Sci Ctr, Pacif Fisheries Environm Lab, Pacific Grove, CA 93950 USA. RP Hobday, AJ (reprint author), CSIRO, POB 1538, Hobart, Tas 7001, Australia. RI Hobday, Alistair/A-1460-2012 OI Hobday, Alistair/0000-0002-3194-8326 NR 55 TC 59 Z9 59 U1 2 U2 7 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD OCT PY 2001 VL 58 IS 10 BP 2021 EP 2036 DI 10.1139/cjfas-58-10-2021 PG 16 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 481LE UT WOS:000171520100012 ER PT J AU Jones, WE Sun, F Curl, RF Allen, MD Evenson, KM Brown, JM AF Jones, WE Sun, F Curl, RF Allen, MD Evenson, KM Brown, JM TI Far-infrared LMR spectroscopic investigation of the quasi-linear molecule DCCN: The nu(5)(1 <- 0) SO CANADIAN JOURNAL OF PHYSICS LA English DT Article ID ASYMMETRIC-TOP MOLECULES; MICROWAVE SPECTROSCOPY; HCCN; QUASILINEARITY; NU(1)+NU(5); SPECTRUM; CARBENE; ENERGY; ALLENE; STATE AB The far-infrared laser magnetic resonance spectrum (FIR LMR) of the v(5) bending vibrational transition of DCCN in its X-3 Sigma (-) State is reported. The DCCN radical was produced inside the spectrometer cavity by the reaction of deuterated acetonitrile with F atoms. DCCN resonances were measured on seven laser lines. Nitrogen hyperfine structure was observed on a number of the resonances. The analysis provides improved accuracy for the separation v(5) = 1 <-- 0 and some of the N-14 hyperfine coupling constants for this isotopomer. C1 Univ Windsor, Dept Chem & Biochem, Sch Phys Sci, Windsor, ON N9B 3P4, Canada. Rice Univ, Dept Chem, Houston, TX 77005 USA. Rice Univ, Rice Quantum Inst, Houston, TX 77005 USA. Natl Inst Stand & Technol, Time & Frequency Div 847, Boulder, CO 80303 USA. Phys & Theoret Chem Lab, Oxford OX1 3QZ, England. RP Jones, WE (reprint author), Univ Windsor, Dept Chem & Biochem, Sch Phys Sci, 401 Sunset Ave, Windsor, ON N9B 3P4, Canada. NR 28 TC 4 Z9 4 U1 0 U2 1 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4204 J9 CAN J PHYS JI Can. J. Phys. PD OCT PY 2001 VL 79 IS 2-3 BP 389 EP 408 DI 10.1139/cjp-79-2-3-389 PG 20 WC Physics, Multidisciplinary SC Physics GA 452QH UT WOS:000169869900024 ER PT J AU Meerts, WL Ozier, I Hougen, JT AF Meerts, WL Ozier, I Hougen, JT TI Anomalous transitions in two-level systems driven by the ac Stark effect SO CANADIAN JOURNAL OF PHYSICS LA English DT Article ID MOLECULAR-BEAM SPECTROSCOPY; INTERNAL-ROTATION; MULTIPHOTON TRANSITIONS; METHYL SILANE; ROTOR AB An unusual type of nonresonant absorption signal produced by the ac Stark effect has been observed in a two-level avoided-crossing system. The theory for these anomalous transitions has been developed. The nonresonant signals have been shown to be caused by the perturbation by the oscillating field of the dephasing of the two-level system at the avoided crossing. A series of measurements of these anomalous transitions has been carried out using the avoided-crossing molecular-beam electric-resonance technique. In addition, different types of resonant multiphoton transitions have been investigated. Results are reported for the AE-barrier anticrossing with J = 1 in CH3SiH3. The experimental findings are in good agreement with the theory developed. C1 Univ Nijmegen, Dept Mol & Laser Phys, NL-6500 GL Nijmegen, Netherlands. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Univ Nijmegen, Dept Mol & Laser Phys, POB 9010, NL-6500 GL Nijmegen, Netherlands. EM Leo.Meerts@sci.kun.nl RI Meerts, W. Leo/B-6172-2008 OI Meerts, W. Leo/0000-0001-6457-3797 NR 19 TC 1 Z9 1 U1 0 U2 2 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0008-4204 EI 1208-6045 J9 CAN J PHYS JI Can. J. Phys. PD OCT PY 2001 VL 79 IS 2-3 BP 533 EP 545 PG 13 WC Physics, Multidisciplinary SC Physics GA 452QH UT WOS:000169869900035 ER PT J AU Van Woert, ML Meier, WN Zou, CZ Beesley, JA Hovey, PD AF Van Woert, ML Meier, WN Zou, CZ Beesley, JA Hovey, PD TI Satellite validation of the May 2000 sea ice concentration fields from the Polar Ice Prediction System SO CANADIAN JOURNAL OF REMOTE SENSING LA English DT Article ID FORECAST MODEL; NUMERICAL-SIMULATION; PERFORMANCE AB The National Ice Center relies upon a coupled ice/ocean model called the Polar Ice Prediction System (PIPS) to provide guidance for its 1-5 day sea ice forecasts. Here we present results on the forecast skill of the sea ice concentration (C) fields from this system for the highly variable month of May 2000. Consistent with previous work on weather model verification, we used the root mean square error, the anomaly correlation and the index of agreement to assess the forecast skill of the system. In all cases, the skill of the model was high (e.g., anomaly correlations >0.7) and, for times out to 72 hours, significantly better than persistence at the 95% confidence level. However, in spite of the overall high hemispheric forecast skill of PIPS, considerable spatial variability exists in the statistics. A threat index, patterned after methodologies developed for tornado forecasting, was also used to assess changes in ice concentration. Specifically, it was used to assess how well PIPS forecasts ice-free regions (C <0.15). Consistent with the previous results, it was found that PIPS does better than persistence. It is suggested, but by no means demonstrated, that these forecast errors arise due to deficiencies in the meteorological fields used to force the ice/ocean model. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD USA. RP Van Woert, ML (reprint author), Natl Ice Ctr, Fed Off Bldg 4,Room 2301,4251 Suitland Rd, Washington, DC 20395 USA. RI Zou, Cheng-Zhi/E-3085-2010; OI Meier, Walter/0000-0003-2857-0550 NR 38 TC 4 Z9 4 U1 0 U2 1 PU CANADIAN AERONAUTICS SPACE INST PI OTTAWA PA 1685 RUSSELL RD, UNIT 1-R, OTTAWA, ON K1G 0N1, CANADA SN 0703-8992 J9 CAN J REMOTE SENS JI Can. J. Remote Sens. PD OCT PY 2001 VL 27 IS 5 BP 443 EP 456 PG 14 WC Remote Sensing SC Remote Sensing GA 503QP UT WOS:000172811700006 ER PT J AU Dedrick, KR Partington, K Van Woert, M Bertoia, CA Benner, D AF Dedrick, KR Partington, K Van Woert, M Bertoia, CA Benner, D TI US National/Naval Ice Center digital sea ice data and climatology SO CANADIAN JOURNAL OF REMOTE SENSING LA English DT Article AB Weekly sea ice charts produced by the National Ice Center (NIC) from 1972 through 1994 have recently been released to the public in support of environmental research. These charts were originally intended as navigation aids for vessels operating Northern Hemisphere sea ice-infested waters. However, it was recognized early on that these data represent a unique resource for Arctic researchers, adding significantly to sea ice data sets compiled by Walsh (1978) and others. Ice concentration records commonly derived from satellite passive microwave data are similar to the NIC data set in terms of resolution, extent and period of record, but these microwave data may suffer from systematic biases related to the imaging process and algorithms used to infer ice concentration from raw data. Although the NIC digital sea ice data set has its own limitations, its starting point precedes that of the passive microwave record and avoids some of its inherent biases. This paper describes the spatial and thematic characteristics of the NIC historical data set, as well as the digital and analog data and analysis methods used to create the data set. This study, also briefly investigates long-term change in Arctic ice cover. The NIC data set reveals that sea ice concentration patterns in the Atlantic and Pacific sectors of the Arctic vary in response to changes in the North Atlantic Oscillation. This result is consistent with the findings of other researchers, who used other data sets. C1 Natl Naval Ice Ctr, Washington, DC 20395 USA. NASA Headquarters, Polar Res Program, Earth Sci Enterprise, Washington, DC USA. NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD USA. Natl Naval Ice Ctr, Washington, DC USA. RP Dedrick, KR (reprint author), Natl Naval Ice Ctr, FB4,Room 2301,4251 Suitland Rd, Washington, DC 20395 USA. NR 26 TC 26 Z9 27 U1 0 U2 2 PU CANADIAN AERONAUTICS SPACE INST PI OTTAWA PA 1685 RUSSELL RD, UNIT 1-R, OTTAWA, ON K1G 0N1, CANADA SN 0703-8992 J9 CAN J REMOTE SENS JI Can. J. Remote Sens. PD OCT PY 2001 VL 27 IS 5 BP 457 EP 475 PG 19 WC Remote Sensing SC Remote Sensing GA 503QP UT WOS:000172811700007 ER PT J AU Wackerman, CC Friedman, KS Pichel, WG Clemente-Colon, P Li, X AF Wackerman, CC Friedman, KS Pichel, WG Clemente-Colon, P Li, X TI Automatic detection of ships in RADARSAT-1 SAR imagery SO CANADIAN JOURNAL OF REMOTE SENSING LA English DT Article ID WAKE DETECTION AB NOAA/NESDIS has initiated a program called the Alaska SAR Demonstration with the goal of demonstrating the utility of RADARSAT-1 C-band SAR imagery to provide useful, timely environmental and resource management information to users in Alaska. One product generated under the program is a list of ship locations. This paper describes the algorithm developed to generate this product by automatically detecting ships based on changes in the local statistics. Using low resolution imagery (100 metres sample spacing) it is shown that ships of lengths greater than 35 metres can be detected (representing 105 ships out of a total of 272 in the test set) with a false alarm rate of 0.01% for a single detection. With high-resolution imagery (50 metres sample spacing) ships of lengths greater than 32 metres can be detected (representing 124 ships out of 272) with a false alarm rate of 0.002% for a single detection. The algorithm is completely automated and takes approximately 10 minutes of elapsed time to run on a ScanSAR Wide B Mode image. C1 Veridian ERIM Int, Ann Arbor, MI 48113 USA. NOAA, NESDIS, WWBG, Camp Springs, MD 20746 USA. RP Wackerman, CC (reprint author), Veridian ERIM Int, POB 134008, Ann Arbor, MI 48113 USA. RI Clemente-Colon, Pablo/F-5581-2010; Pichel, William/F-5619-2010; Li, Xiaofeng/B-6524-2008 OI Pichel, William/0000-0001-6332-0149; Li, Xiaofeng/0000-0001-7038-5119 NR 13 TC 63 Z9 70 U1 4 U2 14 PU CANADIAN AERONAUTICS SPACE INST PI OTTAWA PA 1685 RUSSELL RD, UNIT 1-R, OTTAWA, ON K1G 0N1, CANADA SN 0703-8992 J9 CAN J REMOTE SENS JI Can. J. Remote Sens. PD OCT PY 2001 VL 27 IS 5 BP 568 EP 577 PG 10 WC Remote Sensing SC Remote Sensing GA 503QP UT WOS:000172811700016 ER PT J AU Garboczi, EJ Bentz, DP AF Garboczi, EJ Bentz, DP TI The effect of statistical fluctuation, finite size error, and digital resolution on the phase percolation and transport properties of the NIST cement hydration model SO CEMENT AND CONCRETE RESEARCH LA English DT Article DE hydration; hydration products; electrical properties; transport properties; modeling ID MICROSTRUCTURE DEVELOPMENT; COMPUTER-SIMULATION; DIFFUSIVITY; PASTE; CONDUCTIVITY; PERMEABILITY; PREDICTION; CONCRETE; ROCK AB The National Institute of Standards and Technology (NIST) cement hydration model starts with a three-dimensional digital image of cement particles, and then uses cellular automaton rules to simulate the reaction of cement with water and the development of cement paste microstructure. This stochastic model uses a digital image with a certain resolution to represent the reality of continuum shapes in a fairly small periodic unit cell. As such, it is potentially subject to statistical fluctuation, finite size error, and the effects of digital resolution. This paper evaluates the model in light of these potential sources of error, along with the effects of cement particle size distribution (PSD), water/cement (w/c) ratio, and cement chemistry, by focusing on the phase percolation and transport property predictions of the model. Statistical fluctuation and finite size error are shown to be of minor importance in the model. The effect of digital resolution is significant, however, but different from the case of a finite element or finite difference model. Unlike these cases, the "best" resolution is not necessarily the finest resolution, but must be chosen based on comparison with experiment and various physical length scales present in cement paste. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Bldg Mat Div, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Garboczi, EJ (reprint author), Natl Inst Stand & Technol, Bldg Mat Div, Bldg & Fire Res Lab, 100 Bur Dr,Stop 8621, Gaithersburg, MD 20899 USA. RI Chen, Wei/A-5694-2010 NR 35 TC 92 Z9 96 U1 1 U2 10 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 OCT PY 2001 VL 31 IS 10 BP 1501 EP 1514 DI 10.1016/S0008-8846(01)00593-2 PG 14 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 482WP UT WOS:000171600500014 ER PT J AU Zhu, J Morgan, AB Lamelas, FJ Wilkie, CA AF Zhu, J Morgan, AB Lamelas, FJ Wilkie, CA TI Fire properties of polystyrene-clay nanocomposites SO CHEMISTRY OF MATERIALS LA English DT Article ID FRIEDEL-CRAFTS CHEMISTRY; LAYERED-SILICATE NANOCOMPOSITES; POLYMER AB Polystyrene-clay nanocomposites have been prepared using a bulk polymerization technique. Three new "onium" salts have been used to prepare the nanocomposites, two are functionalized ammonium salts while the third is a phosphonium salt. By TGA/FTIR, both ammonium and phosphonium treatments have been shown to degrade by a Hofmann elimination mechanism at elevated temperatures. TGA/FTIR showed that the phosphonium treatment is the most thermally stable treatment when compared to the two ammonium salts. The nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, strength and elongation at break, as a measure of the mechanical properties, thermogravimetric analysis, and cone calorimetry. The onset temperature of the degradation is increased by about 50 degreesC and the peak heat release rate is reduced by 27-58%, depending upon the amount of clay that is present. The mass loss rates are also significantly reduced in the presence of the clay. C1 Marquette Univ, Dept Chem, Milwaukee, WI 53201 USA. Marquette Univ, Dept Phys, Milwaukee, WI 53201 USA. Natl Inst Stand & Technol, Fire Sci Div, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Wilkie, CA (reprint author), Marquette Univ, Dept Chem, POB 1881, Milwaukee, WI 53201 USA. RI Morgan, Alexander/A-9672-2009 NR 16 TC 488 Z9 500 U1 4 U2 75 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD OCT PY 2001 VL 13 IS 10 BP 3774 EP 3780 DI 10.1021/cm000984r PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 484AY UT WOS:000171669100068 ER PT J AU VanderHart, DL Asano, A Gilman, JW AF VanderHart, DL Asano, A Gilman, JW TI Solid-state NMR investigation of paramagnetic nylon-6 clay nanocomposites. 1. Crystallinity, morphology, and the direct influence of Fe3+ on nuclear spins SO CHEMISTRY OF MATERIALS LA English DT Article ID LAYERED-SILICATE NANOCOMPOSITES; MULTIPLE PULSE NMR; C-13 NMR; MAGNETIC-RESONANCE; POLYMER; POLYPROPYLENE; SPECTRA; REGIONS; SPECTROSCOPY; DIFFUSION AB Several exfoliated nylon-6/clay nanocomposites (NnC's) were investigated and compared with pure nylon-6 using solid-state NMR, both proton and C-13. NnC's had nominally 5 mass % clay and were generated both by blending and by in situ polymerization (IsP). Most of the studied NnC's contained layered, naturally occurring montmorillonite clays having nonstoichiometric amounts of nonexchangeable Mg2+ and Fe3+ ions that substitute into octahedral Al3+ sites along the midplane of the 1-nm-thick clay layers. The Fe3+ ions impart a useful paramagnetism to the clay. Each Mg2+ ion leaves an embedded negative charge that must be neutralized with some cation at the surface of the clay. All clays were initially treated with a cationic so-called organic modifier (OM), often a substituted ammonium ion, which increases the clay layer spacing, attaching ionically to the surface of the clay layers. Clay is found to promote growth of the gamma -crystalline phase of nylon-6 for both blended and IsP NnC's; alpha -crystallites are characteristic of the pure nylon-6. Stability of the gamma -phase to annealing at 214 degreesC was investigated. Conversion of gamma- to alpha -crystallinity during annealing was minimal, except for an injection-molded IsP NnC, which had been exposed to a temperature of 295 degreesC during molding. This high processing temperature produced an irreversible change. An attempt was made to understand, at least qualitatively, the nature of the spectral density of magnetic fluctuations associated with the paramagnetic Fe3+ sites in the clay. For this purpose, we looked directly at the influence of Fe3+ on the C-13 and proton observables in organically modified clays (OMC). We agree with other investigators that the spectral density of paramagnetic fluctuations at the surface of the clay is determined mainly by spin-exchange interactions between Fe3+ sites; thus, the spectral density can be altered by changing the Fe3+ concentration. Moreover, we find that the spectral density is very wide, having strong contributions all the way from mid-kHz fluctuations to MHz fluctuations near the proton Larmor frequencies. Significant variations in the alpha/gamma ratio were also observed in the injection-molded disk, which reflect either a processing-induced heterogeneity in clay dispersion or a significant variation in cooling history from region to region. Proton spin diffusion and multiple-pulse methods were utilized to compare morphologies for a diamagnetic NnC and nylon-6 with the same thermal histories. Long spacing, crystallinity, and the mobility of the noncrystalline nylon-6 segments are very similar for NnC's and nylon-6. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Fire Sci Div, Gaithersburg, MD 20899 USA. RP VanderHart, DL (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 46 TC 127 Z9 128 U1 2 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD OCT PY 2001 VL 13 IS 10 BP 3781 EP 3795 DI 10.1021/cm0110775 PG 15 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 484AY UT WOS:000171669100069 ER PT J AU Vanderhart, DL Asano, A Gilman, JW AF Vanderhart, DL Asano, A Gilman, JW TI Solid-state NMR investigation of paramagnetic nylon-6 clay nanocomposites. 2. Measurement of clay dispersion, crystal stratification, and stability of organic modifiers SO CHEMISTRY OF MATERIALS LA English DT Article ID HYBRID AB In this second paper of a two-part series dealing mainly with NMR characterization of nylon-6/clay nanocomposites (NnC's) having nominally 5 mass % clay, measurements with application to processing are featured. The paramagnetism of the montmorillonite clays, discussed in the first paper, allowed us to use the corresponding spin-diffusion-moderated reduction in longitudinal proton relaxation time, T-1(H), for two purposes, namely, to rank the quality of clay dispersion in NnC families with the same formulation and to investigate morphological stratification of the nylon-6 alpha- and gamma -crystallites with respect to the clay surface. In a group of three NnC's with the same formulation but different melt-blending conditions, variations in T-1(H) correlated well with previously published TEM assessments of the quality of the clay dispersion. Also, in a set of samples from an injection-molded, in situ polymerized NnC disk where strong variations in alpha/gamma ratios were observed, it was found that these differences did not arise from processing-induced inhomogeneities in clay concentration; rather, variations in cooling histories throughout the disk was the more probable cause. In these latter samples, well-defined stratification of the gamma -phase (versus the alpha -phase) crystallites nearer the clay surface did not occur until after annealing at 214 degreesC. We also examined the dependence of NnC T-1(H) on the static field of the measurement. It is clear that the magnitude of the paramagnetic contribution to T-1(H) is a function of field and of Fe3+ concentration in the clay. Trends support the notion that spin-exchange interactions between the electrons on different Fe3+ ions largely define the spectral density of magnetic fluctuations near the clay surface. Some attention was, therefore, given to optimizing Fe3+ concentrations for the best NnC characterization. Finally, we investigated the chemical stability of a particular organic modifier (OM), which is used to pretreat the clay prior to melt blending. The OM, dimethyl, dehydrogenated-tallow ammonium ion, was followed in the process of blending this modified clay with nylon-6 at 240 degreesC. It was found that when such a clay surface was exposed to the nylon-6 during blending, most of the OM on that surface decomposed, releasing a free amine with one methyl and two tallow substituents. However, subsequent melting at 240 degreesC produced no further decomposition. The implication is that the combination of temperature and shear stress in blending causes decomposition, not just temperature alone. The susceptibility to chemical decomposition varied strongly with the OM. Ironically, extensive decomposition of the OM did not result in poor mixing; in fact, as judged by T-1(H), the NnC with the best dispersion of clay also had the most extensively degraded OM. The implications of this degradation for the physical properties have not been explored in detail. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Fire Sci Div, Gaithersburg, MD 20899 USA. RP Vanderhart, DL (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 19 TC 178 Z9 179 U1 1 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD OCT PY 2001 VL 13 IS 10 BP 3796 EP 3809 DI 10.1021/cm011078x PG 14 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 484AY UT WOS:000171669100070 ER PT J AU Burns, JC Turner, CL Tong, G Miller, E Diaz, HF Cayan, DA AF Burns, JC Turner, CL Tong, G Miller, E Diaz, HF Cayan, DA TI Kawasaki disease: A climate connection? SO CLINICAL INFECTIOUS DISEASES LA English DT Meeting Abstract C1 Univ Calif San Diego, Sch Med, La Jolla, CA 92093 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. CDC, NOAA, Boulder, CO USA. RI Burns, Jane/J-6167-2015 NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 1058-4838 J9 CLIN INFECT DIS JI Clin. Infect. Dis. PD OCT 1 PY 2001 VL 33 IS 7 MA 280 BP 1136 EP 1136 PG 1 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA 476KU UT WOS:000171226900306 ER PT J AU Lee, S Song, J AF Lee, S Song, J TI High-speed PVC-based handover control in wireless ATM networks SO COMPUTER COMMUNICATIONS LA English DT Article DE wireless ATM; PVC-based; handover control AB Wireless ATM is expected to provide significantly high bit-rate services to meet the demand for handling multimedia information. In this paper, we propose a handover control scheme utilizing Permanent Virtual Connection (PVC) to reduce handover latency. Handover provisioning is an important function of the mobile wireless ATM network. The reestablishment-based schemes require a new partial path or a completely new connection to be set-up. This might result in being slow and inefficient. So the proposed scheme removes reestablishment procedure reserving PVCs between neighboring, mobility enhanced ATM switches for handover. A simple analytical methodology is presented for overall system organization and for demonstrating the effectiveness of the proposed scheme. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Yonsei Univ, Dept Comp Sci, Soedaemun Gu, Seoul 120749, South Korea. RP Lee, S (reprint author), NIST, Adv Network Technol Div 892, North 820,Room 467,100 Bur Dr,Stop 8920, Gaithersburg, MD 20899 USA. RI Song, Jooseok/G-8615-2012 NR 17 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0140-3664 J9 COMPUT COMMUN JI Comput. Commun. PD OCT 1 PY 2001 VL 24 IS 15-16 BP 1497 EP 1507 DI 10.1016/S0140-3664(01)00295-X PG 11 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 479KC UT WOS:000171402700002 ER PT J AU Shelden, KEW DeMaster, DP Rugh, DJ Olson, AM AF Shelden, KEW DeMaster, DP Rugh, DJ Olson, AM TI Developing classification criteria under the US Endangered Species Act: Bowhead whales as a case study SO CONSERVATION BIOLOGY LA English DT Article ID BALAENA-MYSTICETUS; POPULATION-SIZE; BALEEN WHALES; CONSERVATION; NUMBERS; ISSUES; BAY AB Under the U.S. Endangered Species Act, a species is classified as endangered, threatened, or recovered based on the extent to which its survival is affected by one or more of five subjective factors. A key criticism of the act is that it makes no reference to quantitative or even qualitative parameters of what constitutes "danger of extinction." Without objective standards to guide decisionmakers, classification decisions fall prey to political and social influences. We recommend the development of species-specific, status-determining criteria as a means to rationalize and expedite the listing process and reclassification decisions, independent of the requirement for delisting criteria in recovery plans. Such criteria should (1) clearly define levels of vulnerability, (2) identify gaps in information on life-history Parameters, and (3) address uncertainty in existing data. As a case study, we developed preliminary criteria for bowhead whales (Balaena mysticetus). Thresholds for endangered and threatened status were based on World Conservation Union (IUCN) Red List criteria and population viability analyses. Our analysis indicates that particular attention must be focused on population structure within the species to appropriately classify the degree to which one or more components of a species are vulnerable to extinction. A similar approach could be used in the classification of other species. According to our application of the IUCN criteria and those developed for similar species by Gerber and DeMaster (1999), the Bering Sea population of bowhead whales should be delisted, whereas the other four populations of bowheads should continue to be considered endangered. C1 NOAA, NMFS, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. Univ Washington, Sch Marine Affairs, Seattle, WA 98105 USA. RP Shelden, KEW (reprint author), NOAA, NMFS, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 49 TC 15 Z9 15 U1 2 U2 15 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2001 VL 15 IS 5 BP 1300 EP 1307 DI 10.1046/j.1523-1739.2001.99380.x PG 8 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 481BY UT WOS:000171501100013 ER PT J AU Lindholm, J Barr, B AF Lindholm, J Barr, B TI Comparison of marine and terrestrial protected areas under federal jurisdiction in the United States SO CONSERVATION BIOLOGY LA English DT Article AB There is a significant disparity in the protection of terrestrial and marine environments in the United States. Despite the considerable literature dedicated to the subject of protected areas, both terrestrial and marine, in the United States, we are not aware of work explicitly describing this dichotomy. We compared marine and terrestrial areas under federal jurisdiction to provide a quantitative assessment of the differences between the conservation of land and sea in the United States. Specifically, we compared national marine sanctuaries (including sanctuary preservation areas and ecological reserves) with national parks, national forests, and national wildlife refuges (including national wilderness preservation areas). Our results suggest that marine sanctuaries are fewer in number, smaller in total area, and smaller in percentage of area covered than are terrestrial protected areas. C1 Univ Connecticut, Natl Undersea Res Ctr NW Atlantic & Great Lakes, Groton, CT 06340 USA. US Geol Survey, Conservat Policy & Planning Branch, NOAA, Natl Marine Sanctuary Syst, Woods Hole, MA 02543 USA. RP Lindholm, J (reprint author), Stellwagen Bank Natl Marine Sanctuary, 175 Edward Foster Rd, Scituate, MA 02066 USA. NR 20 TC 5 Z9 6 U1 1 U2 2 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2001 VL 15 IS 5 BP 1441 EP 1444 DI 10.1046/j.1523-1739.2001.00052.x PG 4 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 481BY UT WOS:000171501100028 ER PT J AU Blumen, W Banta, R Burns, SP Fritts, DC Newsom, R Poulos, GS Sun, JL AF Blumen, W Banta, R Burns, SP Fritts, DC Newsom, R Poulos, GS Sun, JL TI Turbulence statistics of a Kelvin-Helmholtz billow event observed in the night-time boundary layer during the Cooperative Atmosphere-Surface Exchange Study field program SO DYNAMICS OF ATMOSPHERES AND OCEANS LA English DT Article; Proceedings Paper CT 3rd Conference on Mixing in Geophysical and Astrophysical Flows CY APR 12-14, 2000 CL UNIV SHEFFIELD, SHEFFIELD, ENGLAND SP European Res Community Flow, Turbulence & Combust, London Math Soc HO UNIV SHEFFIELD DE Kelvin-Helmholtz instability; billows; turbulent mixing; night-time boundary layer ID GRAVITY-WAVES; FINITE-AMPLITUDE; EVOLUTION; INSTABILITY; STABILITY; FLOW AB An apparent shear flow instability occurred in the stably stratified night-time boundary layer on 6 October 1999 over the Cooperative Atmosphere-Surface Exchange Study (CASES-99) site in southeast Kansas. This instability promoted a train of billows which appeared to be in different stages of evolution. Data were collected by sonic anemometers and a high-frequency thermocouple array distributed on a 60 m tower at the site, and a high resolution Doppler lidar (HRDL), situated close to the tower. Data from these instruments were used to analyze the characteristics of the instability and the billow event. The instability occurred in a layer characterized by a minimum Richardson number Ri similar to 0.13, and where an inflection in the background wind profile was also documented. The billows, which translated over the site for approximately 30 min, were approximately L similar to 320 m in length and, after billow evolution they were contained in a layer depth H similar to 30 m. Their maximum amplitude, determined by HRDL data, occurred at a height of 56 m. Billow overturns, responsible for mixing of heat and momentum, and high-frequency intermittent turbulence produce kurtosis, values above the Gaussian value of 3, particularly in the lower part of the active layer. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. NOAA, Environm Technol Lab, Boulder, CO 80305 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Colorado Res Associates NW Res Associates, Boulder, CO 80301 USA. Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. RP Blumen, W (reprint author), Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. RI Burns, Sean/A-9352-2008; Banta, Robert/B-8361-2008; Sun, Jielun/H-6576-2015 OI Burns, Sean/0000-0002-6258-1838; Sun, Jielun/0000-0003-3271-7914 NR 30 TC 70 Z9 71 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0265 J9 DYNAM ATMOS OCEANS JI Dyn. Atmos. Oceans PD OCT PY 2001 VL 34 IS 2-4 BP 189 EP 204 DI 10.1016/S0377-0265(01)00067-7 PG 16 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA 467UK UT WOS:000170722000007 ER PT J AU Steidinger, K Landsberg, J Richardson, RW Truby, E Blakesley, B Scott, P Tester, P Tengs, T Mason, P Morton, S Seaborn, D Litaker, W Reece, K Oldach, D Haas, L Vasta, G AF Steidinger, K Landsberg, J Richardson, RW Truby, E Blakesley, B Scott, P Tester, P Tengs, T Mason, P Morton, S Seaborn, D Litaker, W Reece, K Oldach, D Haas, L Vasta, G TI Classification and identification of Pfiesteria and Pfiesteria-like species SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT CDC National Conference on Pfiesteria: From Biology to Public Health CY OCT 18-20, 2000 CL STONE MT, GEORGIA DE Pfiesteria; cryptoperidiniopsoid; "Lucy"; dinoflagellates; Pfiesteria-like; Kofoidian; plate patterns; morphology ID DINOFLAGELLATE; PISCICIDA; OCELLATUM AB Dinoflagellates can be classified both botanically and zoologically; however, they are typically put in the botanical division Pyrrhophyta. As a group they appear most related to the protistan ciliates and apicomplexans at the ultrastructure level. Within the Pyrrhophyta are both unarmored and armored forms of the dominant, motile flagellated stage. Unarmored dinoflagellates do not have thecal or wall plates arranged in specific series, whereas armored species have plates that vary in thickness but are specific in number and arrangement. In armored dinoflagellates, the plate pattern and tabulation is a diagnostic character at the family, subfamily, and even genus levels. In most cases, the molecular characterization of dinoflagellates confirms the taxonomy on the basis of external morphology; this has been demonstrated for several groups. Together, both genetic and morphological criteria are becoming increasingly important for the characterization, separation, and identification of dinoflagellates species. Pfiesteria and Pfiesteria-like species are thinly armored forms with motile dinospore stages characterized by their distinct plate formulae. Pfiesteria piscicida is the best-known member of the genus; however, there is at least one other species. Other genetically and morphologically related genera, now grouped under the common names of "Lucy," "Shepherd's crook," and cryptoperidiniopsoid, are being studied and described in separate works. All these other heterotrophic dinoflagellate groups, many of which are thought to be benign, co-occur in estuarine waters where Pfiesteria has been found. C1 Florida Marine Res Inst, Florida Fish & Wildlife Conservat Commiss, St Petersburg, FL 33701 USA. Natl Ocean Serv, Natl Ocean & Atmospher Adm, Beauft Lab, Beaufort, NC USA. Univ Maryland, Sch Med, Baltimore, MD 21201 USA. Coll William & Mary, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. Natl Ocean Serv, Natl Ocean & Atmospher Adm, Charleston, SC USA. Old Dominion Univ, Dept Biol Sci, Norfolk, VA 23529 USA. Univ N Carolina, Program Mol Biol & Biotechnol, Chapel Hill, NC 27599 USA. Univ Maryland, Ctr Biotechnol, Baltimore, MD 21201 USA. RP Steidinger, K (reprint author), Florida Marine Res Inst, Florida Fish & Wildlife Conservat Commiss, 100 8th Ave SE, St Petersburg, FL 33701 USA. OI Oldach, David/0000-0002-8811-2562 NR 25 TC 32 Z9 34 U1 1 U2 5 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD OCT PY 2001 VL 109 SU 5 BP 661 EP 665 DI 10.2307/3454911 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 487UN UT WOS:000171894300003 PM 11677173 ER PT J AU Pinckney, JL Paerl, HW Tester, P Richardson, TL AF Pinckney, JL Paerl, HW Tester, P Richardson, TL TI The role of nutrient loading and eutrophication in estuarine ecology SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT CDC National Conference on Pfiesteria: From Biology to Public Health CY OCT 18-20, 2000 CL STONE MT, GEORGIA DE biogeochemistry; coastal; estuary; eutrophic; management; microbial; phytoplankton; zooplankton ID NEUSE-RIVER ESTUARY; DISSOLVED ORGANIC-CARBON; PHYTOPLANKTON BLOOM DYNAMICS; NORTH-ATLANTIC OCEAN; CHESAPEAKE BAY; COASTAL EUTROPHICATION; WATER-COLUMN; GROWTH-RATE; GYMNODINIUM-CATENATUM; MARINE-PHYTOPLANKTON AB Eutrophication is a process that can be defined as an increase in the rate of supply of organic mat-ter (OM) to an ecosystem. We provide a general overview of the major features driving estuarine eutrophication and outline some of the consequences of that process. The main chemical constituent of OM is carbon (C), and therefore rates of eutrophication are expressed in units of C per area per unit time. OM occurs in both particulate and dissolved forms. Allochthonous OM originates outside the estuary, whereas autochthonous OM is generated within the system, mostly by primary producers or by benthic regeneration of OM. The supply rates of limiting nutrients regulate phytoplankton productivity that contributes to inputs of autochthonous OM. The trophic status of an estuary is often based on eutrophication rates and can be categorized as oligotrophic (< 100 g C m(-2) y(-1)), mesotrophic (100-300 g C m(-2) y(-1)), eutrophic (300-500 g C m(-2) Y-1), or hypertrophic (> 500 g C m(-2) y(-1)). Ecosystem responses to eutrophication depend on both export rates (flushing, microbially mediated losses through respiration, and denitrification) and recycilng/regeneration rates within the estuary. The mitigation of the effects of eutrophication involves the regulation of inorganic nutrient (primarily N and P) inputs into receiving waters. Appropriately scaled and parameterized nutrient and hydrologic controls are the only realistic options for controlling phytoplankton blooms, algal toxicity, and other symptoms of eutrophication-in estuarine ecosystems. C1 Texas A&M Univ, Dept Oceanog, College Stn, TX 77843 USA. Univ N Carolina, Inst Marine Sci, Morehead City, NC 28557 USA. Natl Ocean Serv, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC USA. RP Pinckney, JL (reprint author), Texas A&M Univ, Dept Oceanog, MS 3146, College Stn, TX 77843 USA. NR 124 TC 94 Z9 98 U1 6 U2 39 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD OCT PY 2001 VL 109 SU 5 BP 699 EP 706 DI 10.2307/3454916 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 487UN UT WOS:000171894300008 PM 11677178 ER PT J AU Luttenberg, D Turgeon, D Higgins, J AF Luttenberg, D Turgeon, D Higgins, J TI Report from the NOAA workshops to standardize protocols for monitoring toxic Pfiesteria species and associated environmental conditions SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT CDC National Conference on Pfiesteria: From Biology to Public Health CY OCT 18-20, 2000 CL STONE MT, GEORGIA DE dinoflagellate; fish bioassay; fish kill; harmful algal bloom; lesion; monitoring; Pfiesteria; Pfiesteria-like organism; Pfiesteria piscicida; Pfiesteria shumwayae; PLO; presumptive count; toxic Pfiesteria complex; toxic Pfiesteria outbreak; TPC ID FISH KILLS; DINOFLAGELLATE; PISCICIDA; COMPLEX AB Long-term monitoring of water quality, fish health, and plankton communities in susceptible bodies of water is crucial to identify the environmental factors that contribute to outbreaks of toxic Pfiesteria complex (TPC) species. In the aftermath of the 1997 toxic Pfiesteria outbreaks in North Carolina and Maryland, federal and several state agencies agreed that there was a need to standardize monitoring protocols. The National Oceanic & Atmospheric Administration convened two workshops that brought together state, federal, and academic resource managers and scientific experts to a) seek consensus on responding to and monitoring potential toxic Pfiesteria outbreaks; b) recommend standard parameters and protocols to characterize water quality, fish health, and plankton at historical event sites and potentially susceptible sites; and c) discuss options for integrating monitoring data sets from different states into regional and national assessments. Workshop recommendations included the development of a three-tiered TPC monitoring strategy: Tier 1, rapid event response; Tier 2, comprehensive assessment; and Tier 3, routine monitoring. These tiers correspond to varying levels of water quality, fish health, and plankton monitoring frequency and intensity. Under the strategy, sites are prioritized, depending upon their history and susceptibility to TPC events, and assigned an appropriate level of monitoring activity. Participants also agreed upon a suite of water quality parameters that should be monitored. These recommendations provide guidance to state and federal agencies conducting rapid-response and assessment activities at sites of suspected toxic Pfiesteria outbreaks, as well as to states that are developing such monitoring programs for the first time. C1 NOAA, Ctr Coastal Monitoring & Assessment N SCI1, Natl Ocean Serv, Silver Spring, MD 20910 USA. NOAA, Ctr Sponsored Coastal Ocean Res, Natl Ocean Serv, Silver Spring, MD 20910 USA. RP Turgeon, D (reprint author), NOAA, Ctr Coastal Monitoring & Assessment N SCI1, Natl Ocean Serv, 1305 East West Highway, Silver Spring, MD 20910 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD OCT PY 2001 VL 109 SU 5 BP 707 EP 710 DI 10.2307/3454917 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 487UN UT WOS:000171894300009 PM 11677179 ER PT J AU Melo, AC Moeller, PDR Glasgow, H Burkholder, JM Ramsdell, JS AF Melo, AC Moeller, PDR Glasgow, H Burkholder, JM Ramsdell, JS TI Microfluorimetric analysis of a purinergic receptor (P2X(7)) in GH(4)C(1) rat pituitary cells: Effects of a bioactive substance produced by Pfiesteria piscicida SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT CDC National Conference on Pfiesteria: From Biology to Public Health CY OCT 18-20, 2000 CL STONE MT, GEORGIA DE GH(4)C(1); Pfiesteria; purinergic receptors; P2X(7); toxin ID PHARMACOLOGICAL CHARACTERIZATION; MICROGLIAL CELLS; CATION CHANNELS; P-2Z RECEPTOR; ATP; DINOFLAGELLATE; ACTIVATION; PURINORECEPTOR; MAITOTOXIN; EXPRESSION AB Pfiesteria piscicida Steidinger & Burkholder is a toxic dinoflagellate that leads to fish and human toxicity. It produces a bioactive substance that leads to cytotoxicity of GH(4)C(1) rat pituitary cells. Extracellular adenosine F-triphosphate (ATP) acting on P2X(7) purinergic receptors induces the formation of a nonselective cation channel, causing elevation of the cytosolic free calcium followed by a characteristic permeabilization of the cell to progressively larger ions and subsequent cell lysis. We investigated whether GH4C1 rat pituitary cells express functional P2X7 receptors, and if so, are they activated by a bioactive substance isolated from toxic P. piscicida cultures. We tested the selective agonist 2'-3'-O-(benzoyl-4-benzoyl)-ATP (BzATP) and antagonists piridoxalphosphate-6-azophenyl-2'-4'-disulfonic acid (PPADS) and oxidized-ATP (oxATP) using elevated cytosolic free calcium in Fura-2 loaded cells, and induced permeability of these cells to the fluorescent dye YO-PRO-1 as end points. We demonstrated that in GH(4)C(1) cells, BzATP induces both the elevation of cytosolic free calcium and the permeabilization of the cell membrane. ATP-induced membrane permeabilization was inhibited by PPADS reversibly and by oxATP irreversibly. The putative Pfiesteria toxin (pPfTx) also elevated cytosolic free calcium in Fura-2 in GH(4)C(1) cells and increased the permeability to YO-PRO-1 in a manner inhibited fully by oxATP. This study indicates that GH(4)C(1) cells express a purinoceptor with characteristics consistent with the P2X7 subtype, and that pPfTx mimics the kinetics of cell permeabilization by ATP. C1 NOAA, Coastal Res Branch, Ctr Coastal Environm Hlth & Biomol Res, Natl Ocean Serv,Marine Biotoxins Program, Charleston, SC 29412 USA. N Carolina State Univ, Dept Bot, Raleigh, NC 27695 USA. RP Ramsdell, JS (reprint author), NOAA, Coastal Res Branch, Ctr Coastal Environm Hlth & Biomol Res, Natl Ocean Serv,Marine Biotoxins Program, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 43 TC 24 Z9 24 U1 0 U2 0 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD OCT PY 2001 VL 109 SU 5 BP 731 EP 737 DI 10.2307/3454920 PG 7 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 487UN UT WOS:000171894300012 PM 11677182 ER PT J AU Moeller, PDR Morton, SL Mitchell, BA Sivertsen, SK Fairey, ER Mikulski, TM Glasgow, H Deamer-Melia, NJ Burkholder, JM Ramsdell, JS AF Moeller, PDR Morton, SL Mitchell, BA Sivertsen, SK Fairey, ER Mikulski, TM Glasgow, H Deamer-Melia, NJ Burkholder, JM Ramsdell, JS TI Current progress in isolation and characterization of toxins isolated from Pfiesteria piscicida SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT CDC National Conference on Pfiesteria: From Biology to Public Health CY OCT 18-20, 2000 CL STONE MT, GEORGIA DE assay; chromatography; GH(4)C(1); Pfiesteria piscicida; toxin bioassay ID FISH KILLS; DINOFLAGELLATE; ASSAY AB The isolation and partial purification of toxic substances derived from Pfiesteria piscicida Steidinger & Burkholder extracts is described. Four distinct bioassay systems were used to monitor bioactivity of the P. piscicida extracts, including a high throughput cell cytotoxicity assay and a reporter gene assay as well as assays using brine shrimp and fish. Using these bioassays to guide fractionation, we have isolated two distinct, active fractions from Pfiesteria culture medium and cell mass extracts on the basis of their solubility characteristics. We have identified and characterized a bioactive lipophilic substance from Pfiesteria-derived extracts as di(2-ethylhexyl)phthalate, a commonly used plasticizer, The source of this typically man-made substance has been identified as originating from Instant Ocean (Aquarium Systems, Mentor, OH, USA), a commercially available seawater salt mixture used to prepare our mass culture growth medium. We have developed chromatographic methodology to isolate a bioactive polar compound isolated from extracts of Pfiesteria culture and presently report the characterization of the activity of this substance. The molecular structural analysis of the polar active component(s) using mass spectrometry and nuclear magnetic resonance spectroscopy is currently under way. C1 NOAA, NOS, Ctr Coastal Environm Hlth & Biomol Res, Marine Biotoxins Program, Charleston, SC 29412 USA. N Carolina State Univ, Ctr Appl Aquat Ecol, Raleigh, NC 27695 USA. RP Moeller, PDR (reprint author), NOAA, NOS, Ctr Coastal Environm Hlth & Biomol Res, Marine Biotoxins Program, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 16 TC 42 Z9 43 U1 0 U2 2 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD OCT PY 2001 VL 109 SU 5 BP 739 EP 743 DI 10.2307/3454921 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 487UN UT WOS:000171894300013 PM 11677183 ER PT J AU Pennington, PL Scott, GI AF Pennington, PL Scott, GI TI Toxicity of atrazine to the estuarine phytoplankter Pavlova sp (Prymnesiophyceae): Increased sensitivity after long-term, low-level population exposure SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE phytoplankton; estuarine; atrazine; increased sensitivity; long-term population exposure ID RISK-ASSESSMENT AB Phytoplankton are potentially more at risk to the adverse effects of herbicides than many other organisms in estuarine ecosystems. The focus of this study was to characterize the toxicity of a widely used herbicide, atrazine, to a single species of phytoplankton. The nanoplankter Pavlova sp. was grown under controlled laboratory conditions and was used to elucidate shortterm, high-level population effects of atrazine. Secondly, a long-term, multigenerational population exposure was performed with a low level of atrazine followed by an additional short-term, high-level exposure on the same population with no recovery period. The 96-h growth rate of 50% effective concentration (EC50) for Pavlova sp. was 147 mug/L (95% CI = 116.4-178.7 mug/L). Longterm exposure at 20 mug/L for four (batch culture) growth cycles (similar to 20 generations) had no significant effect on the growth rate of Pavlova sp. except during the fourth growth cycle, However, a subsequent short-term, high-level 96-h exposure inoculated from the long-term, low-level exposed population showed increased sensitivity to atrazine (96-h growth rate EC50 = 96.0 mug/L, 95% CI = 90.2-103.7 mug/L). Multi generational exposure to atrazine appeared to render phytoplankton significantly more sensitive (35%) to atrazine effects. Given the documented persistence of atrazine in surface waters, long-term exposure to low levels of atrazine without recovery may lead to shifts in species sensitivity and potential alterations in phytoplankton population dynamics. C1 Univ Charleston, Dept Biol, Grice Marine Biol Lab, Charleston, SC 29412 USA. US Dept Commerce, Natl Ocean & Atmospher Adm, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Charleston, SC 29412 USA. RP Pennington, PL (reprint author), Univ Charleston, Dept Biol, Grice Marine Biol Lab, 205 Fort Johnson, Charleston, SC 29412 USA. EM paul.pennington@noaa.gov NR 25 TC 15 Z9 15 U1 0 U2 1 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0730-7268 EI 1552-8618 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD OCT PY 2001 VL 20 IS 10 BP 2237 EP 2242 DI 10.1897/1551-5028(2001)020<2237:TOATTE>2.0.CO;2 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 503UT UT WOS:000172820300016 PM 11596756 ER PT J AU Fairey, R Long, ER Roberts, CA Anderson, BS Phillips, BM Hunt, JW Puckett, HR Wilson, CJ AF Fairey, R Long, ER Roberts, CA Anderson, BS Phillips, BM Hunt, JW Puckett, HR Wilson, CJ TI An evaluation of methods for calculating mean sediment quality guideline quotients as indicators of contamination and acute toxicity to amphipods by chemical mixtures SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE sediment quality guideline quotients; amphipod; toxicity; chemical mixtures ID MARINE; ECOSYSTEMS; FLORIDA; BAY AB Mean sediment quality guideline quotients (mean SQGQs) were developed to represent the presence of chemical mixtures in sediments and are derived by normalizing a suite of chemicals to their respective numerical sediment quality guidelines (SQGs). Mean SQGQs incorporate the number of SQGs exceeded and the degree to which they are exceeded and are used for comparison with observed biological effects in the laboratory or field. The current research makes it clear. however, that the number and type of SQGs used in the derivation of these mean quotients can influence the ability of mean SQGQ values to correctly predict acute toxicity to marine amphipods in laboratory toxicity tests. To determine the optimal predictive ability of mean SQGQs, a total of 18 different chemical combinations were developed and compared. The ability of each set of mean SQGQs to correctly predict the presence and absence of acute toxicity to amphipods was determined using three independent databases (n = 605 2753. 226). Calculated mean SQGQ values for all chemical combinations ranged from 0.002 to 100. The mean SQGQ that was most predictive of acute toxicity to amphipods is calculated as SQGQ1 = ((Sigma ([cadmium]/4.21)([copper]/270)([lead]/112.18)([silver]/1.77)([zinc]/ 410)([total chlordane]/6)([dieldrin]/8)([total PAH(OC)]/1,800)([total PCB]/400)/9)). Both the incidence and magnitude of acute toxicity to amphipods increased with increasing SQGQ1 values. To provide better comparability between regions and national surveys, SQGQ1 is recommended to serve as the standard method for combination of chemicals and respective SQGs when calculating mean SQGQs. C1 San Jose State Univ Fdn, Moss Landing Marine Labs, Moss Landing, CA 95039 USA. NOAA, NCCOS, Ctr Coastal Monitoring & Assessment, Seattle, WA 98115 USA. Univ Calif Davis, Marine Pollut Studies Lab, Monterey, CA 93940 USA. Calif Dept Fish & Game, Marine Pollut Studies Lab, Monterey, CA 93940 USA. Calif State Water Resouces Control Board, Bays & Estuaries Unit, Sacramento, CA 92444 USA. RP Fairey, R (reprint author), San Jose State Univ Fdn, Moss Landing Marine Labs, 7544 Sandholdt Rd, Moss Landing, CA 95039 USA. NR 39 TC 61 Z9 68 U1 4 U2 20 PU SETAC PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3367 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD OCT PY 2001 VL 20 IS 10 BP 2276 EP 2286 DI 10.1897/1551-5028(2001)020<2276:AEOMFC>2.0.CO;2 PG 11 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 503UT UT WOS:000172820300021 PM 11596761 ER PT J AU Kepa, H Kutner-Pielaszek, J Blinowski, J Twardowski, A Majkrzak, CF Story, T Kacman, P Galazka, RR Ha, K Swagten, HJM De Jonge, WJM Sipatov, AY Volobuev, V Giebultowicz, TM AF Kepa, H Kutner-Pielaszek, J Blinowski, J Twardowski, A Majkrzak, CF Story, T Kacman, P Galazka, RR Ha, K Swagten, HJM De Jonge, WJM Sipatov, AY Volobuev, V Giebultowicz, TM TI Antiferromagnetic interlayer coupling in ferromagnetic semiconductor EuS/PbS(001) superlattices SO EUROPHYSICS LETTERS LA English DT Article ID MULTILAYERS; TRANSITION; EXCHANGE; FE/SI/FE; MODEL AB Antiferromagnetic coupling between ferromagnetic layers has been observed for the rst time in an all-semiconductor superlattice structure EuS/PbS(001), by neutron scattering and magnetization measurements. Spin-dependent superlattice band structure effects are invoked to explain the possible origin and the strength of the observed coupling. C1 Univ Warsaw, Dept Phys, PL-00681 Warsaw, Poland. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. Eindhoven Univ Technol, Dept Appl Phys, NL-5600 MB Eindhoven, Netherlands. Eindhoven Univ Technol, COBRA, NL-5600 MB Eindhoven, Netherlands. Kharkov State Polytech Univ, UA-310002 Kharkov, Ukraine. Oregon State Univ, Dept Phys, Corvallis, OR 97331 USA. RP Kepa, H (reprint author), Univ Warsaw, Dept Phys, Ul Hoza 69, PL-00681 Warsaw, Poland. OI Sipatov, Alexander/0000-0002-2693-2135 NR 21 TC 45 Z9 45 U1 4 U2 8 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD OCT PY 2001 VL 56 IS 1 BP 54 EP 60 DI 10.1209/epl/i2001-00487-7 PG 7 WC Physics, Multidisciplinary SC Physics GA 480KD UT WOS:000171459800009 ER PT J AU Widmann, JF Sheppard, DT Lueptow, RM AF Widmann, JF Sheppard, DT Lueptow, RM TI Non-intrusive measurements in fire sprinkler sprays SO FIRE TECHNOLOGY LA English DT Article DE fire sprinklers; drop size; drop velocity; phase Doppler interferometry; particle image velocimetry; sprinkler sprays AB The results of phase Doppler interferometry (PDI) and particle image velocimetry (PIV) measurements to characterize the water sprays produced by fire sprinklers are presented. The large size of the water drops produced by fire sprinklers, and the relatively large coverage area of the spray, present significant challenges when attempting to characterize these sprays. These difficulties are especially relevant when using PDI because large drops and large coverage areas may result in attenuation of the transmitting laser beams. For the fire sprinkler investigated, it was determined that attenuation of the laser beam resulted in over-counting of drops due to burst splitting, a situation in which the Doppler signals from single drops are misinterpreted as being due to multiple drops. This effect was minimized by carefully choosing the operating conditions of the PDI processing electronics. PIV measurements provide velocity profiles that can be used as input for fire dynamics simulations to predict the effect of sprinkler sprays on fires. The results from the PIV measurements show good agreement with the velocity measurements obtained from PDI in the core of the spray, but poorer agreement along the sprinkler axis. The discrepancy was attributed to recirculation zones present in the experimental facility and possible biasing of the PIV measurements towards the larger drops. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Underwriters Labs, Large Scale Fire Res, Northbrook, IL 60062 USA. Northwestern Univ, Dept Mech Engn, Evanston, IL 60208 USA. RP Widmann, JF (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RI Lueptow, Richard /B-6740-2009; Lueptow, Richard/J-4998-2012; OI Lueptow, Richard/0000-0002-1855-1471 NR 23 TC 12 Z9 12 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0015-2684 J9 FIRE TECHNOL JI Fire Technol. PD OCT PY 2001 VL 37 IS 4 BP 297 EP 315 DI 10.1023/A:1012727614590 PG 19 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 510UW UT WOS:000173226500002 ER PT J AU Harms, J Sylvia, G AF Harms, J Sylvia, G TI A comparison of conservation perspectives between scientists, managers, and industry in the West Coast groundfish fishery SO FISHERIES LA English DT Article AB There are several assumptions regarding the behavior and motivations of participants in fishery management that may hinder the effectiveness of the management process. In this research, we examine whether the commercial fishing industry is a homogeneous group whose decision-making is dominated by short-term economic considerations to the detriment of long-term resource conservation. Mail surveys were sent to scientists, managers, and industry members in the West Coast groundfish fishery to examine attitudes on conservation, resource abundance, and biological risk. Results demonstrate that although scientists and industry considered themselves conservation-minded, scientists were relatively critical of industry's conservation ethic. Scientists and industry differed strongly in their perception of resource abundance, but found common ground in their assessments of acceptable levels of biological and economic risks. In general, industry demonstrated considerable diversity in their responses, contradicting assumptions that industry is a monolithic group with little regard for resource conservation. Results indicate a disjuncture between industry's stated concerns and their observed participation in discarding, over-harvesting, or habitat destruction. However, this disjuncture may be the result of misaligned institutional incentives, rather than myopic values and beliefs. This evidence suggests a need to redesign institutions and property rights in order to align the interests of industry, scientists, and managers in conducting effective science and sustainably managing the West Coast groundfish fishery. C1 NOAA, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Harms, J (reprint author), NOAA, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. NR 24 TC 7 Z9 7 U1 0 U2 2 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 OCT PY 2001 VL 26 IS 10 BP 6 EP 15 DI 10.1577/1548-8446(2001)026<0006:ACOCPB>2.0.CO;2 PG 10 WC Fisheries SC Fisheries GA 480PH UT WOS:000171470200002 ER PT J AU Walsh, WA Kleiber, P AF Walsh, WA Kleiber, P TI Generalized additive model and regression tree analyses of blue shark (Prionace glauca) catch rates by the Hawaii-based commercial longline fishery SO FISHERIES RESEARCH LA English DT Article DE blue shark; catch rates; generalized additive model; regression tree AB Generalized additive model (GAM) and regression tree analyses were conducted with blue shark, Prionace glauca, catch rates (catch per set) as reported by National Marine Fisheries Service observers serving aboard Hawaii-based commercial longline vessels from March 1994 through December 1997 (N=2010 longline sets). The objective was to use GAM and regression tree methodology to relate catch rates to a tractable suite of readily measured or computed variables. Because the predictor variables are also either provided in or easily computed from the logbooks that commercial vessels submit upon landing fish for sale, it is likely that a model or models fitted to accurate observer data could then be applied on a fleet-wide basis to serve as a standard of comparison for the logbooks. The GAM included nine spatio-temporal, environmental, and operational variables and explained 72.1% of the deviance of blue shark catch rates. Latitude exerted the strongest effects of any individual variable; longitude was the most influential variable when adjusted for the effects of all other factors. Relatively cold sea surface temperatures were associated with high catch rates. The initial regression tree included 68 terminal nodes and I I predictors. It was refined to a final tree with 42 terminal nodes, which reduced the root mean deviance by 65.3%. The tree was partitioned first on latitude 26.6 degreesN, and then branched out to reach terminal nodes after 2-8 additional partitionings. Sets south of this latitude were characterized by lower catch rates and partitionings on a greater number and variety of predictors. Northerly sets were characterized by higher and more variable blue shark catch rates. Predictions from the two analyses were highly correlated (r=0.903. P much less than0.001). Moreover, use of these methods in combination aided greatly in the interpretation of results. We conclude that GAM and regression tree analyses can be usefully employed in the assessment of blue shark catch rates in this fishery. We suggest that either or both of these models could serve as comparison standards for commercial logbooks. Published by Elsevier Science B.V. C1 Univ Hawaii, Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA. RP Walsh, WA (reprint author), Univ Hawaii, Honolulu Lab, Natl Marine Fisheries Serv, 2570 Dole St, Honolulu, HI 96822 USA. NR 12 TC 51 Z9 55 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD OCT PY 2001 VL 53 IS 2 BP 115 EP 131 DI 10.1016/S0165-7836(00)00306-4 PG 17 WC Fisheries SC Fisheries GA 469GR UT WOS:000170806600002 ER PT J AU Arendt, MD Lucy, JA Munroe, TA AF Arendt, MD Lucy, JA Munroe, TA TI Seasonal occurrence and site-utilization patterns of adult tautog, Tautoga onitis (Labridae), at manmade and natural structures in lower Chesapeake Bay SO FISHERY BULLETIN LA English DT Article ID TAUTOGOLABRUS-ADSPERSUS LABRIDAE; ULTRASONIC TELEMETRY; FISH POPULATIONS; FEMALE CUNNER; HOME RANGES; REEFS; TRANSMITTERS; MOVEMENTS; VIRGINIA; GROWTH AB Ultrasonic transmitters were surgically implanted into adult tautog (n=27,400-514 mm TL) to document seasonal occurrence and site utilization at four sites situated within known tautog habitat near Cape Charles, Virginia, in lower Chesapeake Bay. Tagged tautog were released at the same sites where originally caught within 2 h of capture. Sites were continuously monitored with automated acoustic receivers between 9 November 1998 and 13 October 1999. Two sites consisted of natural bedform. materials and two sites consisted of manmade materials. Ninety-four percent of tautog (n=15) released in fall 1998 remained inshore during winter at sustained water temperatures of 5-8 degreesC, rather than moved offshore during winter as documented for tautog off New York, Rhode Island, and Massachusetts. Ninety-one percent (n=10) of tautog released in spring 1999 remained inshore during summer when water temperature was 27 degreesC and in the absence of an important food item, blue mussels (Mytilus edulis). These findings conflict with assertions that tautog move to cooler water in summer when water temperatures reach 20 degreesC. Tautog released at natural bedform. sites were detected only at these sites throughout the study. Tautog released at manmade structures also displayed high site-utilization patterns, but several tautog periodically moved 2-10.2 km away from these sites over featureless bottom, a known deterrent to emigration for large temperate labrids in other waters. Benthic communities were similar at manmade sites and natural bedform sites, and movement away from manmade sites may have been influenced by habitat size as well as habitat structure. Understanding temporal and spatial utilization of habitats is an important first step to identifying essential fish habitat and to evaluating and protecting fishery resources within Chesapeake Bay and elsewhere. C1 Coll William & Mary, Sch Marine Sci, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA. Virginia Inst Marine Sci, Sea Grant Marine Advisory Program, Gloucester Point, VA 23062 USA. Natl Museum Nat Hist, Natl Marine Fisheries Serv, Natl Systemat Lab, Washington, DC 20560 USA. RP Arendt, MD (reprint author), Marine Resources Res Inst, Dept Nat Resources, Marine Resources Div, 217 Ft Johnson Rd, Charleston, SC 29422 USA. NR 41 TC 29 Z9 29 U1 0 U2 5 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 OCT PY 2001 VL 99 IS 4 BP 519 EP 527 PG 9 WC Fisheries SC Fisheries GA 494QZ UT WOS:000172298500001 ER PT J AU Lo, NCH Hunter, JR Charter, R AF Lo, NCH Hunter, JR Charter, R TI Use of a continuous egg sampler for ichthyoplankton surveys: application to the estimation of daily egg production of Pacific sardine (Sardinops sagax) off California SO FISHERY BULLETIN LA English DT Article ID NORTHERN ANCHOVY; ENGRAULIS-MORDAX; VERTICAL-DISTRIBUTION; ESTIMATING BIOMASS; FISH EGGS; LARVAE; STOCK; GEOSTATISTICS; MODEL AB In 1996, using the continuous underway fish egg sampler (CUFES),we carried out a preliminary study with the daily egg production method (DEPM) for estimating fish biomass of Pacific sardine, Sardinops sagax. Full-water-column abundance of sardine eggs was correlated with the abundance of eggs taken at 3-m depth with a CUFES; however direct conversion of CUFES samples to the full-water-column abundance, required by the DEPM, would add considerable variance to an estimate of daily egg production. Our preliminary study also indicated that the average size of an egg patch for Pacific sardine was 22 km diameter and that all stages of sardine eggs were not equally vulnerable. to a CUFES at 3-m depth. Using these findings as a guide, in 1997 we carried out an adaptive allocation DEPM survey in which the numbers of sardine eggs collected with the CUFES were used to determine subsequent locations of vertical net tows. All the vertical net tows were taken in a high-density stratum where the CUFES collected at least two eggs per minute; egg density in this stratum was computed by using only vertical tows. The remaining survey area, where the CUFES collected fewer than two eggs per minute, constituted a low-density stratum where egg density was estimated by using the ratio of CUFES egg abundance in these two strata multiplied by the egg density in the high-density stratum. Conventional statistics were used because the sampling units were survey lines spaced at 22-km, or greater intervals. An acceptable level of precision (CV=21%) for a daily production of 2.57 eggs 0.05 m(2)/d (51.4 eggs m2/d), was achieved by using only 141 vertical net tows. Therefore, the CUFES will enhance the DEPM by increasing precision of the estimates, or by reducing costs in relation to a survey composed of only vertical water-column tows, when the CUFES is used adaptively to establish sampling strata for vertical water column tows. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92037 USA. RP Lo, NCH (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, 8604 La Jolla Shores, La Jolla, CA 92037 USA. NR 43 TC 32 Z9 33 U1 1 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 OCT PY 2001 VL 99 IS 4 BP 554 EP 571 PG 18 WC Fisheries SC Fisheries GA 494QZ UT WOS:000172298500004 ER PT J AU Loher, T Armstrong, DA Stevens, BG AF Loher, T Armstrong, DA Stevens, BG TI Growth of juvenile red king crab (Paralithodes camtschaticus) in Bristol Bay (Alaska) elucidated from field sampling and analysis of trawl-survey data SO FISHERY BULLETIN LA English DT Article ID RECRUITMENT; PATTERNS; LOBSTER; MODEL; SEA AB An analysis of in situ growth rate was conducted for juvenile red king crab (Paralithodes camtschaticus) in Bristol Bay, Alaska. Growth of early juveniles (similar to2-40 mm CL; age 0-3 yr) was determined by fitting seasonalized Gompertz growth models to length-frequency data. The parameters, of the growth model and resulting size-at-age estimates were compared with those from studies conducted at Unalaska and Kodiak Islands by fitting the same growth model to published length-frequency data from separate sources. Growth of late juvenile and early reproductive crabs, similar to 30-100 mm carapace length.(CL), was examined by analyzing length-frequency data from the National Marine Fisheries Service annual Bering Sea trawl survey from 1975 through 1999. Mean CL associated with strong size, modes of crabs in Bristol Bay length-frequency distributions was resolved by using the FiSAT software package (FAO-ICLARM Stock Assessment Tools) to track the modal size progression of strong year classes and assign mean size-at-age characteristics to the stock. Growth of early juvenile crabs was slower in Bristol Bay than that observed by other researchers at Unalaska or Kodiak. Sizes at 1, 2, and 3 years after settlement were estimated to be similar to9 mm, 23 mm, and 47 mm CL in Bristol Bay compared with 16 mm, 38 mm, and 66 mm CL at Unalaska; at Kodiak, estimated sizes of 12 mm and 42 mm were obtained for age-1 and age-2 crabs, respectively. Within the Bristol Bay trawl survey data, a total of 24 modes were identified for both males. and females < 100 mm CL, which included the modal progression of two year classes that presumably settled in 1976 and 1990. The 1976 year class grew slowly and would not have recruited to the reproductive stock until similar to9 years after settlement, whereas the 1990 year class appeared to recruit at similar to8 years after settlement. Both estimates indicate that Bristol Bay red king crabs are older at reproductive maturity than the similar to6 years after settlement presently assumed. An attempt to resolve discrete mean size-at-age from the length-frequency data met with little success. because variability in growth between year classes markedly obscured size-at-age characteristics in the stock. C1 Univ Washington, Sch Fisheries & Aquat Sci, Seattle, WA 98195 USA. Natl Marine Fisheries Serv, Kodiak Fisheries Res Ctr, AFSC Kodiak Lab, Kodiak, AK 99615 USA. RP Loher, T (reprint author), Int Publ Halibut Commiss, POB 95009, Seattle, WA 98145 USA. NR 46 TC 19 Z9 22 U1 1 U2 10 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 OCT PY 2001 VL 99 IS 4 BP 572 EP 587 PG 16 WC Fisheries SC Fisheries GA 494QZ UT WOS:000172298500005 ER PT J AU Somerton, DA Munro, P AF Somerton, DA Munro, P TI Bridle efficiency of a survey trawl for flatfish SO FISHERY BULLETIN LA English DT Article ID CAPTURE EFFICIENCY; THEORETICAL-MODEL; SAMPLING TRAWL; GEAR AB A bottom trawl catch of flatfish is composed of fish that were initially in the path of the trawl net and fish that were initially in the path of the bridles and were subsequently herded into the net path. Bridle efficiency (i.e. the proportion of fish in the bridle path that are herded into the net path) for seven species of flatfish was estimated by fitting a model of the herding process to data collected during a field experiment. The experiment consisted of repeatedly making trawl hauls with three different bridle lengths. The model was then fitted to the catch of each species, by length class, as a function of the widths of the net and door spreads at the three bridle lengths. Bridle efficiency was independent of body length for five species (yellowfin sole, Limanda aspera; flat-head sole, Hippoglossoides elassodon; rock sole, Lepidopsetta bilineata; Dover sole, Microstomus pacificus; rex sole, Glyptocephalus zachirus) nd ranged from 0.22 for rex sole to 0.40 for rock sole. Bridle efficiency declined with increasing body length for two species (English sole, Parophrys vetulus; Pacific sanddab, Citharichthys sordidus), ranging from about 0.35 to 0.10 over the lengths sampled. C1 Alaska Fisheries Sci Ctr, Seattle, WA 98125 USA. RP Somerton, DA (reprint author), Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98125 USA. NR 19 TC 21 Z9 22 U1 3 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 OCT PY 2001 VL 99 IS 4 BP 641 EP 652 PG 12 WC Fisheries SC Fisheries GA 494QZ UT WOS:000172298500010 ER PT J AU Porter, SM Brown, AL Bailey, KM AF Porter, SM Brown, AL Bailey, KM TI Estimating live standard length of net-caught walleye pollock (Theragra chalcogramma) larvae using measurements in addition to standard length SO FISHERY BULLETIN LA English DT Article ID FORMALIN CONCENTRATION; HERRING LARVAE; PRESERVATION; SHRINKAGE; BODY; OTOLITHS; ETHANOL; CAPTURE; GROWTH; FISH C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Porter, SM (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 25 TC 11 Z9 11 U1 1 U2 2 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 OCT PY 2001 VL 99 IS 4 BP 691 EP 696 PG 6 WC Fisheries SC Fisheries GA 494QZ UT WOS:000172298500016 ER PT J AU Gregory, LF Schmid, JR AF Gregory, LF Schmid, JR TI Stress responses and sexing of wild Kemp's ridley sea turtles (Lepidochelys kempii) in the Northeastern Gulf of Mexico SO GENERAL AND COMPARATIVE ENDOCRINOLOGY LA English DT Article ID PLASMA-CORTICOSTERONE; CARETTA-CARETTA; CHELONIA-MYDAS; TESTOSTERONE; LIZARD; HORMONES; WATERS; COAST AB Plasma corticosterone, glucose, and testosterone concentrations were measured in wild, immature specimens of the highly endangered Kemp's ridley sea turtle (Lepidochelys kempii) to determine effects of acute handling stress. Thirty-nine free-ranging turtles were captured by entanglement net near the Cedar Keys, Florida. Blood samples were collected immediately after retrieval from the net, and at 30 min (n = 15) and at 60 min (n = 29) thereafter. Mean plasma corticosterone and glucose concentrations increased significantly with time. No significant difference was observed over time for mean testosterone concentrations. Approximately half of the turtles demonstrated an increase in plasma testosterone after 60 min of captivity while the others demonstrated a decrease. initial testosterone concentrations were used to determine the sex of individual turtles. Fifty-nine percent of turtles were classified as female, 33% as male, and 8% as indeterminant. The results of this study demonstrate a responsive hypothalamic-pituitary-adrenal axis and hyperglycemia in immature Kemp's ridley turtles during acute handling stress. (C) 2001 Academic Press. C1 Univ Florida, Dept Zool, Gainesville, FL 32611 USA. Univ Florida, Archie Carr Ctr Sea Turtle Res, Gainesville, FL 32611 USA. NOAA, SE Fisheries Sci Ctr, Natl Marine Fisheries Serv, Miami, FL 33149 USA. RP Gregory, LF (reprint author), Univ Florida, Dept Zool, POB 118525, Gainesville, FL 32611 USA. NR 36 TC 35 Z9 36 U1 3 U2 17 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0016-6480 J9 GEN COMP ENDOCR JI Gen. Comp. Endocrinol. PD OCT PY 2001 VL 124 IS 1 BP 66 EP 74 DI 10.1006/gcen.2001.7683 PG 9 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 484RE UT WOS:000171702700007 PM 11703072 ER PT J AU Crawford, JH Davis, DD Chen, G Buhr, M Oltmans, S Weller, R Mauldin, L Eisele, F Shetter, R Lefer, B Arimoto, R Hogan, A AF Crawford, JH Davis, DD Chen, G Buhr, M Oltmans, S Weller, R Mauldin, L Eisele, F Shetter, R Lefer, B Arimoto, R Hogan, A TI Evidence for photochemical production of ozone at the South Pole surface SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPOSPHERIC OZONE; ANTARCTICA; SNOW AB Observations of OH, NO, and actinic flux at the South Pole surface during December 1998 suggest a surprisingly active photochemical environment which should result in photochemical production of ozone. Long-term South Pole in situ ozone data as well as sonde data also appear to support this conclusion. Other possible factors contributing to ozone variability such as stratospheric influence and the origin of air transported to the South Pole are also explored. Based on box model calculations it is estimated that photochemistry could add 2.2 to 3.6 ppbv/day of ozone to surface air parcels residing on the Antarctic polar plateau. Although the oxidizing potential of the polar plateau appears to be exceptionally high for a remote site, it is unlikely that it has a significant impact on surrounding regions such as the Southern Ocean and the Antarctic free troposphere. These new findings do suggest, however, that the enhanced oxidizing power of the polar plateau may need to be considered in interpreting the chemical history of climate proxy species in ice cores. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Alfred Wegener Inst Polar & Marine Res, D-27570 Bremerhaven, Germany. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80305 USA. New Mexico State Univ, Carlsbad Environm Monitoring & Res Ctr, Carlsbad, NM 88220 USA. USA, Cold Reg Res & Engn Lab, Hanover, NH 03755 USA. Sonoma Technol Inc, Golden, CO USA. RP Crawford, JH (reprint author), NASA, Langley Res Ctr, 21 Langley Blvd, Hampton, VA 23681 USA. RI Crawford, James/L-6632-2013; Lefer, Barry/B-5417-2012 OI Crawford, James/0000-0002-6982-0934; Lefer, Barry/0000-0001-9520-5495 NR 14 TC 62 Z9 63 U1 0 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 2001 VL 28 IS 19 BP 3641 EP 3644 DI 10.1029/2001GL013055 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 476GF UT WOS:000171217300005 ER PT J AU Harrison, DE Vecchi, GA AF Harrison, DE Vecchi, GA TI January 1999 Indian Ocean cooling event SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MADDEN-JULIAN OSCILLATION; TEMPERATURE; SYSTEM AB Unexpectedly strong sub-seasonal SST variability over the tropical Indian Ocean has been observed by the TRMM microwave imager, which provides unprecedented tropical SST information in the presence of clouds. In January-February 1999 SST averaged over an area 20 degrees longitude by 10 degrees latitude cooled by similar to1.5 degreesC over 10 days and warmed by similar to1.25 degreesC in the following week. Local changes were up to +/-3 degreesC. There were strong variations in atmospheric convection and surface wind stress associated with the SST variability. The evolution of the convection suggests a feedback from the SST changes into atmospheric convection. Net air-sea heat-flux cannot account for the observed cooling; oceanic processes are fundamental to this event. The roles of such sub-seasonal ocean-atmosphere interactions in the evolution of the Madden-Julian Oscillation, the seasonal and the interannual variability of Indian Ocean SST deserve further investigation. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98115 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. RP Harrison, DE (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI Vecchi, Gabriel/A-2413-2008; Harrison, Don/D-9582-2013 OI Vecchi, Gabriel/0000-0002-5085-224X; NR 14 TC 63 Z9 64 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 OCT 1 PY 2001 VL 28 IS 19 BP 3717 EP 3720 DI 10.1029/2001GL013506 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 476GF UT WOS:000171217300024 ER PT J AU Stephens, C Levitus, S Antonov, J Boyer, TP AF Stephens, C Levitus, S Antonov, J Boyer, TP TI On the Pacific Ocean regime shift SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERDECADAL VARIABILITY; NORTHERN-HEMISPHERE; TEMPERATURE; OSCILLATION AB The temporal variability of Pacific Ocean upper ocean heat content is examined for the 1948-1998 period using gridded, objectively analyzed temperature anomaly fields. Results indicate a "regime shift" in upper ocean temperature structure occurred in conjunction with the atmospheric shift in sea level pressure around 1975 leading to warming (cooling) in the eastern (western) equatorial Pacific. The shift is a basin-wide phenomenon affecting the thermal structure from 60 degreesS to 70 degreesN. EOF analysis of the Pacific Ocean heat content (0-125 m.) shows a shift from a relatively cool to a warm state in the equatorial Pacific during the mid-1970s. Further analysis of the gridded temperature anomaly fields shows equatorial warming to be as much as 1.5 degreesC and a cooling in the North Pacific of 1 degreesC, down to 250 meters, after the mid-1970s. Overall, the analysis indicates the "regime shift" continues through 1998 with no signs of returning to a cooler phase. C1 NOAA, Natl Oceanog Data Ctr, Silver Spring, MD 20910 USA. RP Stephens, C (reprint author), NOAA, Natl Oceanog Data Ctr, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 21 TC 44 Z9 46 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 2001 VL 28 IS 19 BP 3721 EP 3724 DI 10.1029/2000GL012813 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 476GF UT WOS:000171217300025 ER PT J AU Akmaev, RA AF Akmaev, RA TI Seasonal variations of the terdiurnal tide in the mesosphere and lower thermosphere: a model study SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR; ATMOSPHERE; MIDDLE; OZONE; PARAMETERIZATION AB Observations of the terdiurnal (8-hour) tidal wind oscillations in the mesosphere and lower thermosphere (MLT) reveal strong seasonal and latitudinal variations. The tidal amplitudes reach a maximum of about 15-20 m s(-1) at midlatitudes in winter. The vertical phase progression corresponds to very long vertical wavelengths. During summer the amplitudes are typically weaker and the phases are less regular. First simulations of the terdiurnal tide with the Spectral Mesosphere/Lower Thermosphere Model are presented. The model explicitly accounts for the solar thermal excitation in the middle and upper atmosphere and reproduces the salient features of the terdiurnal wind oscillations well. The preferential solar excitation of antisymmetric terdiurnal modes capable of propagating into the MLT combined with an asymmetric atmospheric response appears to be primarily responsible for the observed seasonal variations. Nonlinear interactions of the diurnal and semidiurnal tides are demonstrated to make a noticeable in situ contribution to the excitation of the terdiurnal tide at 95-100 km, especially during equinox. C1 NOAA, Space Environm Ctr, R, Boulder, CO 80305 USA. Univ Colorado, Boulder, CO 80309 USA. RP Akmaev, RA (reprint author), NOAA, Space Environm Ctr, R, 325 Broadway, Boulder, CO 80305 USA. NR 26 TC 34 Z9 35 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 2001 VL 28 IS 19 BP 3817 EP 3820 DI 10.1029/2001GL013002 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 476GF UT WOS:000171217300049 ER PT J AU Gaune-Escard, M Fuller, J AF Gaune-Escard, M Fuller, J TI Virtual molten salt laboratory: Dream or reality? SO HIGH TEMPERATURE MATERIALS AND PROCESSES LA English DT Article; Proceedings Paper CT 6th International Conference on Molten Slages, Fluxes and Salts CY JUN 12-17, 2000 CL STOCKHOLM, SWEDEN SP Swedish Iron Producers Assoc, Acad Finland, Helsinki Univ Technol, Royal Inst Technol, Imatra Steel Oy Ab, AB Sandvik Steel, Outokumpu Oy, Avesta Sheffield AB, Rautaruukki Oy, Hoganas AB, Assoc Finnish Steel, SSAB Swedish Steel & Metal Producers, Tinfos Jernverk AS, Vargon Alloys AB, Fundia AB, Granges AB, Partek Nordkalk AB, Scana Ind ASA, Uddeholm Technol AB, Kobolde AB, Uddenholm Tooling AB, Erasteel Kloster AB, ASM Int, CIM Bulletin, Chinese Soc Met, IAS, Argentinean Iron & Steel Inst, Indian Inst Met, Iron & Steel Inst Japan, Iron & Steel Soc, Argentinean Soc Met, Minerals Met & Mat Soc, German Soc Glass Technol, Verein Deutsch Eisenhuttenleute, Ctr Rech Met, Inst Mat, Norwegian Met Soc, Korean Inst Met & Mat, Finnish Assoc Min & Met Engineers AB The genesis of the Molten Salt Database, realized as early as 1967 with the publication of the Molten Salt Handbook by George Janz, is as relevant today as it was over 30 years ago. Building a world-class, critically evaluated database is a difficult and complex process involving considerable time and money. Ultimately, the success of the project depends on positive interactions between a diverse group of people - support staff to identify and collect relevant literature, scientists to extract and evaluate the data, database experts to design and build the necessary data architecture and interfaces, database reviewers to ensure that the database is of the highest quality, and marketing staff to ensure the widest dissemination of the database. The advent of the World Wide Web (WWW) has provided another exciting component to this paradigm - a global database structure that enables direct data deposition and evaluation by the scientific community. Ongoing efforts in this respect will be described. C1 IUSTI, CNRS UMR 6595, F-13453 Marseille, France. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Gaune-Escard, M (reprint author), IUSTI, CNRS UMR 6595, Technopole Chateau Gombert,5 Rue Enrico Fermi, F-13453 Marseille, France. NR 1 TC 1 Z9 1 U1 0 U2 0 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-6455 J9 HIGH TEMP MAT PR-ISR JI High Temp. Mater. Process. PD OCT PY 2001 VL 20 IS 3-4 BP 309 EP 312 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 489WA UT WOS:000172014400019 ER PT J AU Van Dolah, FM Roelke, D Greene, RM AF Van Dolah, FM Roelke, D Greene, RM TI Health and ecological impacts of harmful algal blooms: Risk assessment needs SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Article; Proceedings Paper CT 5th Symposium of EPA and the National-Health-and-Environmental-Effects-Laboratory CY JUN 06-08, 2000 CL RES TRIANGLE PK, NC SP EPA, Natl Hlth & Environm Effects Res Lab DE algal toxins; harmful algal blooms; phytoplankton; PSP; NSP; ASP; DSP; PEAS; ciguatera; risk assessment ID BREVE RED TIDE; DOMOIC ACID; PFIESTERIA-PISCICIDA; CARIBBEAN-CIGUATOXINS; SODIUM-CHANNELS; SHELLFISH TOXINS; COASTAL WATERS; INLAND WATERS; IDENTIFICATION; FISH AB The symposium session, Indicators for Effects and Predictions of Harmful Algal Blooms, explored the current state of indicators used to assess the human health and ecological risks caused by harmful algal blooms, and highlighted future needs and impediments that must be overcome in order to provide a complete risk assessment of their impacts. Six recognized human poisoning syndromes resulting from algal toxins (paralytic, neuro toxic, amnesic, diarrhetic shellfish poisonings, ciguatera. fish poisoning, and putative estuary associated syndrome) impact human health through consumption of contaminated seafood, direct contact with bloom water, or inhalation of aerosolized toxin. Thorough health risk assessment for the variety of algal toxins is hampered to varying degrees because either the toxin has not been identified or indicators for exposure and effects remain poorly defined. Predicting the occurrence and determining the impacts of harmful algal blooms in coastal ecosystems are the two major ecological risk assessment needs. In the former case, the hazard is the suite of conditions that trigger bloom initiation, magnify bloom intensity or support bloom longevity, whereas in the latter case, the hazard is the algal toxin. In both cases, indicators (of triggering mechanisms, exposure, and effects) are better defined for some HAB species and toxins than others, but are by no means complete. C1 NOAA, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, Natl Ocean Serv, Charleston, SC 29412 USA. Texas A&M Univ, Dept Wildlife & Fisheries Sci, College Stn, TX 77843 USA. US EPA, Natl Hlth & Environm Effects Res Lab, Gulf Ecol Div, Gulf Breeze, FL 32561 USA. RP Van Dolah, FM (reprint author), NOAA, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, Natl Ocean Serv, Charleston, SC 29412 USA. EM fran.vandolah@noaa.gov RI Roelke, Daniel/B-5766-2008; Greene, Richard/G-9685-2013 NR 81 TC 44 Z9 45 U1 2 U2 42 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD OCT PY 2001 VL 7 IS 5 BP 1329 EP 1345 PG 17 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 492CF UT WOS:000172149200027 ER PT J AU Stumpf, RP AF Stumpf, RP TI Applications of satellite ocean color sensors for monitoring and predicting harmful algal blooms SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Article; Proceedings Paper CT 5th Symposium of EPA and the National-Health-and-Environmental-Effects-Laboratory CY JUN 06-08, 2000 CL RES TRIANGLE PK, NC SP EPA, Natl Hlth & Environm Effects Res Lab DE SeaWiFS; chlorophyll; harmful algal bloom; remote sensing; Gulf of Mexico; Florida ID RED-TIDE DINOFLAGELLATE; GYMNODINIUM BREVE; TRANSPORT; FLORIDA AB The new satellite ocean color sensors offer a means of detecting and monitoring algal blooms in the ocean and coastal zone. Beginning with SeaWiFS (Sea Wide Field-of-view Sensor) in September 1997, these sensors provide coverage every 1 to 2 days with 1-km pixel view at nadir. Atmospheric correction algorithms designed for the coastal zone combined with regional chlorophyll algorithms can provide good and reproducible estimates of chlorophyll, providing the means of monitoring various algal blooms. Harmful algal blooms (HABs) caused by Karenia brevis in the Gulf of Mexico are particularly amenable to remote observation. The Gulf of Mexico has relatively clear water and K. brevis, in bloom conditions, tends to produce a major portion of the phytoplankton biomass. A monitoring program has begun in the Gulf of Mexico that integrates field data from state monitoring programs with satellite imagery, providing an improved capability for the monitoring of K. brevis blooms. C1 NOAA, Natl Ocean Serv, Ctr Coastal Monitoring & Assessment, Silver Spring, MD 20910 USA. RP Stumpf, RP (reprint author), NOAA, Natl Ocean Serv, Ctr Coastal Monitoring & Assessment, 1305 East West Highway,Code N-SCI1, Silver Spring, MD 20910 USA. EM Richard.stumpf@noaa.gov NR 15 TC 58 Z9 61 U1 3 U2 21 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD OCT PY 2001 VL 7 IS 5 BP 1363 EP U15 DI 10.1080/20018091095050 PG 7 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 492CF UT WOS:000172149200029 ER PT J AU Fogarty, MJ Myers, RA Bowen, KG AF Fogarty, MJ Myers, RA Bowen, KG TI Recruitment of cod and haddock in the North Atlantic: a comparative analysis SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE recruitment variability; resilience to exploitation ID MARINE DEMERSAL FISH; GADUS-MORHUA; MELANOGRAMMUS-AEGLEFINUS; PLANKTON PRODUCTION; GEORGES BANK; LARVAL SIZE; VARIABILITY; STOCKS; FECUNDITY; MORTALITY AB We examined recruitment patterns of cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) from eight regions in the North Atlantic (Georges Bank, Browns Bank, the Eastern Scotian Shelf, the Faroe Plateau, Iceland. the Barents Sea. the North Sea, and West of Scotland). The selection was based on the availability of contemporaneous estimates of stock and recruitment for both species within each location. We considered the following metrics for both species by region: recruitment variability (measured as absolute numbers at age I and as deviations from a fitted stock recruitment curve), the rate of recruitment at low spawning stock sizes (the maximum reproductive rate. a measure of resilience of the stock to exploitation) and autocorrelation in recruitment adjusted for spawning stock size. We also examined the correlation of cod and haddock recruitment within regions. Differences in recruitment variability and resilience between cod and haddock in paired comparison tests were highly significant. Haddock consistently exhibited higher recruitment variability and lower resilience than cod. Autocorrelation in recruitment of the two species within region was related possibly indicating serial correlation in forcing mechanisms affecting both species. Cod and haddock exhibited moderate synchrony in recruitment patterns within regions. In six out of the eight regions, the correlation between recruitment (adjusted for spawning stock size) was similar to0.5. suggesting that common environmental conditions experienced by both species did affect recruitment. Research-vessel survey information available for three of the regions (North Sea, Barents Sea, and Georges Bank) and one additional location (Gulf of Maine) were analyzed for evidence of density dependence and for levels of post-larval abundance variability, Cod exhibited stronger density-dependent mortality in three out of four regions. Post-larval abundance variability was not different between the two species. C1 NOAA, Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. Dalhousie Univ, Dept Biol, Halifax, NS B3H 4J1, Canada. RP Fogarty, MJ (reprint author), NOAA, Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. NR 56 TC 39 Z9 39 U1 3 U2 21 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 OCT PY 2001 VL 58 IS 5 BP 952 EP 961 DI 10.1006/jmsc.2001.1108 PG 10 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 483NL UT WOS:000171641100004 ER PT J AU Manning, JP Lough, RG Naimie, CE Churchill, JH AF Manning, JP Lough, RG Naimie, CE Churchill, JH TI Modelling the effect of a slope-water intrusion on advection of fish larvae in May 1995 on Georges Bank SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE advection; fish larvae; modelling; Georges Bank; shelfbreak jet; drifters ID MIDDLE ATLANTIC BIGHT; GULF-OF-MAINE; SHELF-BREAK; CIRCULATION; FRONTS; SUMMER; FLUX AB In the spring of 1995, an intrusion of warm/salty slope water occurred on the southern flank of Georges Bank. As observed on several cross-bank hydrographic and acoustic Doppler current profiler sections. this intrusion resulted in a narrow (10 km) but intense shelfbreak jet (30 cm s(-1) westward residual) in the near-surface waters. A satellite tracked drifter with a drogue located in the core of this jet (15 m) travelled 120 km to the west in 5.5 d. To examine this process and demonstrate the potential redistribution of fish larvae (collected with bongo net hauls) in the presence of a slope-water intrusion, a finite-element 3D circulation model has been initialized with the observed CTD density field. Moored velocity records are assimilated into the model to estimate the oceanic boundary elevations of a limited-area grid. The simulated particle tracks indicate enhanced along-bank flow relative to the long-term seasonal mean and a downwelling convergence zone in the vicinity of the shelf/slope front. The model resolves most of the subtidal flow and provides insight into the vertical advection of the animals and potential mechanisms of retention and loss. C1 NOAA, Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. Dartmouth Coll, Hanover, NH 03755 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. RP Manning, JP (reprint author), NOAA, Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. NR 25 TC 10 Z9 10 U1 0 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD OCT PY 2001 VL 58 IS 5 BP 985 EP 993 DI 10.1006/jmsc.2001.1095 PG 9 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 483NL UT WOS:000171641100008 ER PT J AU Murawski, SA Rago, PJ Trippel, EA AF Murawski, SA Rago, PJ Trippel, EA TI Impacts of demographic variation in spawning characteristics on reference points for fishery management SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE stock-recruitment; maturation cohorts; Atlantic cod; spawning characteristics ID COD GADUS-MORHUA; BIOLOGICAL REFERENCE POINTS; CAPTIVE ATLANTIC COD; REPRODUCTIVE SUCCESS; POPULATION-DYNAMICS; EGG SIZES; RECRUITMENT; AGE; VIABILITY; LARVAE AB Parametric relationships of recruitment to an index of parental stock size assume the latter is proportionally related to spawning potential. irrespective of the demographic composition of adults. Recent empirical information. however, suggests that reproduction by older and experienced females is more successful than by young and inexperienced females. New models are developed incorporating the proportion of each age group spawning for the first. second, etc., time (from information contained in the maturity ogive) and differences in the survival of eggs and larvae in relation to the demography of spawners (based on experimental results). A series of spawning metrics [spawning-stock biomass (SSB), egg production, hatched egg production. viable larval production] and associated recruitment-based fishing mortality reference points (F-med, F-crash, and the F that allows at least one lifetime spawning per recruit) are contrasted for the Georges Bank Atlantic cod (Gadus morhua) stock. The time-series of spawning intensity is significantly altered when hatched eggs or viable larvae are used as the metric. reflecting the contribution of first- and second-time spawners in some years. and the increasing trend in F. The effect of reduced average maternal size in relation to egg viability was a more important factor contributing to discrepancies with SSB than was spawning experience in relation to hatching success. Percent maximum spawning potential (%MSP) per recruit curves in relation to F are steeper (i.e, result in lower values of %MSP for a given F) for hatched eggs and viable larvae than for SSB or egg production per recruit. Lifetime expected numbers of spawnings per recruit are significantly reduced when the effects of spawning experience on egg hatching success are included, And finally. although point estimates of F-med and F-crash are similar using SSB and viable larval production, the median F-crash estimated from 5000 bootstrap realizations of the Beverton-Holt stock recruitment Curve for viable larvae is much lower than that from SSB. with narrower confidence bounds. Our results suggest that traditional approaches to F-based reference points using SSB systematically overestimate the resiliency of stocks to fishing. If age-at-spawning is at least partially heritable, then intense fishing on younger ages may exert high levels of selection for early maturity with negative impacts on net reproductive effort and trait diversity. C1 Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. Fisheries & Oceans Canada, Dept Fisheries, St Andrews, NB E0G 2X0, Canada. Oceans Biol Stn, St Andrews, NB E0G 2X0, Canada. RP Murawski, SA (reprint author), Natl Marine Fisheries Serv, Woods Hole, MA 02543 USA. EM steve.murawski@noaa.gov NR 43 TC 110 Z9 120 U1 1 U2 16 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1054-3139 EI 1095-9289 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD OCT PY 2001 VL 58 IS 5 BP 1002 EP 1014 DI 10.1006/jmsc.2001.1097 PG 13 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 483NL UT WOS:000171641100010 ER PT J AU Megrey, BA Hinckley, S AF Megrey, BA Hinckley, S TI Effect of turbulence on feeding of larval fishes: a sensitivity analysis using an individual-based model SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE fish larvae; Latin Hypercube Sampling; wind-induced turbulence ID DOME-SHAPED RELATIONSHIP; PLANKTON CONTACT RATES; SMALL-SCALE TURBULENCE; GULF-OF-ALASKA; THERAGRA-CHALCOGRAMMA; WALLEYE POLLOCK; ENCOUNTER RATES; PACIFIC-OCEAN; PHYTOPLANKTON; ENVIRONMENTS AB Recent research has shown that turbulence can be important in the feeding of larval fishes. The interplay of turbulence with other important factors affecting larval feeding and growth rates is less known because of the difficult problems associated with multi-factor in situ experiments. We use an individual-based model (IBM) of the early life stages of walleye pollock (Theragra chulcogramma) to examine the sensitivity of growth and mortality to turbulence. This probabilistic and mechanistic model follows individual fish through the egg, yolk-sac larvae, feeding larvae, and juvenile stages, and includes development, behaviour, feeding, bioenergetics, and growth for each life stage. Biological processes are driven by physical factors (temperature, salinity, and turbulence) derived from a companion hydrodynamic model and configured for environmental conditions prevalent in 1987. A foraging submodel explicitly incorporates the effect of turbulence, prey density, and larval size. Monte Carlo simulations using Latin Hypercube Sampling methods were used to perform a sensitivity analysis. The error analysis examines the relative importance of various feeding-related factors on larval growth and mortality. Model results conform to wind-induced turbulence/contact-encounter rate theory with maximum consumption rates occurring at windspeeds of 7.2 m s(-1). Reactive distance, minimum pursuit time, and weight-length conversion parameters were the most important input parameters affecting the turbulence-consumption processes. The rank order of important input parameters shows that the weight-length conversion power coefficient and reactive distance (directly through the reactive distance-length proportionality coefficient) were two factors that influenced the largest number (17 out of 24) and largest percentage (71%) of output variables. Feeding depth was ranked third, influencing 50% of the output variables. Our results show that smaller and younger larvae are more sensitive to turbulent effects than are larger and older larvae. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Megrey, BA (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 46 TC 29 Z9 30 U1 1 U2 8 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 OCT PY 2001 VL 58 IS 5 BP 1015 EP 1029 DI 10.1006/jmsc.2001.1104 PG 15 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 483NL UT WOS:000171641100011 ER PT J AU Hermann, AJ Hinckley, S Megrey, BA Napp, JM AF Hermann, AJ Hinckley, S Megrey, BA Napp, JM TI Applied and theoretical considerations for constructing spatially explicit individual-based models of marine larval fish that include multiple trophic levels SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE biophysical models; individual-based models; recruitment; spawning ID EDDY-RESOLVING MODEL; EARLY-LIFE HISTORY; OF-ALASKA SHELF; SHELIKOF-STRAIT; WALLEYE POLLOCK; FISHERIES OCEANOGRAPHY; THERAGRA-CHALCOGRAMMA; STANDING STOCK; PACIFIC-OCEAN; MIXED-LAYER AB Individual-based modelling (IBM) techniques offer many advantages for spatially explicit modelling of marine fish early life history. However, computationally efficient methods are needed for incorporating spatially explicit circulation and prey dynamics into IBMs. Models of nutrient-phytoplankton-zooplankton (NPZ) dynamics have traditionally been formulated in an Eulerian (fixed spatial grid) framework, as opposed to the pseudo-Lagrangian (individual-following) framework of some IBMs. We describe our recent linkage of three models for the western Gulf of Alaska: (1) a three-dimensional, eddy-resolving, wind- and runoff-driven circulation model, (2) a probabilistic IBM of growth and mortality for egg and larval stages of walleye pollock (Theragra chalcogramma), and (3) an Eulerian, stage-structured NPZ model which specifies production of larval Pollock prey items. Individual fish in the IBM are tracked through space using daily velocity fields generated from the hydrodynamic model, along with self-directed vertical migrations of Pollock appropriate to each life stage. The NPZ dynamics are driven by the same velocity, temperature. and salinity fields as the pollock IBM, and provide spatially and temporally varying prey fields to that model. The resulting prey fields yield greater variance of individual fish attributes (e.g. length), relative to models with spatially uniform prey, Practical issues addressed include the proper time filtering and storage of circulation model output for subsequent use by biological models, and use of different spatial grids for physical and biological dynamics. We demonstrate the feasibility and computational costs of our coupled approach using specific examples from the western Gulf of Alaska. C1 Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98115 USA. NOAA, Natl Marine Fisheries Serv, Seattle, WA 98115 USA. RP Hermann, AJ (reprint author), Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98115 USA. NR 34 TC 43 Z9 45 U1 0 U2 12 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 OCT PY 2001 VL 58 IS 5 BP 1030 EP 1041 DI 10.1006/jmsc.2001.1087 PG 12 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 483NL UT WOS:000171641100012 ER PT J AU Hinckley, S Hermann, AJ Mier, KL Megrey, BA AF Hinckley, S Hermann, AJ Mier, KL Megrey, BA TI Importance of spawning location and timing to successful transport to nursery areas: a simulation study of Gulf of Alaska walleye pollock SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE biophysical models; individual-based models; recruitment; spawning ID EDDY-RESOLVING MODEL; EARLY-LIFE-HISTORY; THERAGRA-CHALCOGRAMMA; SHELIKOF-STRAIT; WESTERN GULF; OF-ALASKA; LARVAL; SHELF; CIRCULATION; STOCK AB We conducted a model experiment to examine the hypothesis that the spatial and temporal specificity of spawning of walleye pollock (Theragra chalcogramma) in Shelikof Strait, Alaska, evolved to optimize physical transport to the juvenile nursery area near the Shumagin Islands some 375 km to the southwest. The alternative hypothesis is that factors other than physical transport alone must also be important in the choice of spawning location and timing. We used a coupled biophysical model consisting of a three-dimensional hydrodynamic model of the currents in the region, an individual-based model of the early life stages of pollock. and a nutrient-phytoplankton zooplankton model that provides a spatially and temporally dynamic source of food for larval pollock, Results showed that fish spawned to the South of Kodiak Island, or too early (February) or too late (July), did not reach the Shumagin Island nursery area by early September. However, the potential region and time of spawning that did allow successful transport to the nursery area was much broader than the observed spawning region and time. Therefore, factors other than physical transport alone must be considered in explaining the specificity of the location and timing of spawning for this stock. C1 Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Hinckley, S (reprint author), Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 33 TC 41 Z9 47 U1 0 U2 3 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 OCT PY 2001 VL 58 IS 5 BP 1042 EP 1052 DI 10.1006/jmsc.2001.1096 PG 11 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 483NL UT WOS:000171641100013 ER PT J AU Smith, PE Horne, JK Schneider, DC AF Smith, PE Horne, JK Schneider, DC TI Spatial dynamics of anchovy, sardine, and hake pre-recruit stages in the California Current SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE anchovy (Engraulis mordax); sardine (Sardinops sagax); hake (Merluccius productus); whiting; fish larvae; juvenile fish; rate diagrams; dimensionless ratios; Eulerian; immigration; emigration; somatic growth; demographics; kinematics ID EARLY LIFE STAGES; FISH GROWTH-RATE; MERLUCCIUS-PRODUCTUS; PACIFIC HAKE; NORTHERN ANCHOVY; ENGRAULIS-MORDAX; EXPLICIT MODELS; TIME-SERIES; SCALE; POPULATION AB Three genera, Engraulis, Sardinops, and Merlucciu have coincident spawning and juvenile brood areas in most eastern and western boundary currents throughout the world, The CalCOFI survey program has amassed a 50-year data series on location and timing of spawning and the resultant recruitment of anchovy, sardine, and hake in the California Current region. Use of existing Lefkovitch matrix population projection models for these three species allows evaluation of the spatial and temporal scales that govern the biological and physical interactions. We present rate diagrams for hake and construct comparable diagrams for anchovy and sardine in a common, variable environment, Rate diagrams depict the relative importance of demographic (natality and mortality), growth. and kinematic (passive and active movement) processes to a quantity of interest as a function of spatial and temporal scale. Results confirm that the scale of observations will have to be manipulated to expose the importance of any combination of processes for life history stages among these species. Field sampling systems have not yet responded adequately to mesoscale features (50 km) persisting over months. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. NOAA, Great Lakes Environm Res Lab, Seattle, WA 98115 USA. Mem Univ Newfoundland, Ctr Ocean Sci, St Johns, NF A1C 5S7, Canada. RP Smith, PE (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, 8604 La Jolla Shores Dr,POB 271, La Jolla, CA 92038 USA. NR 52 TC 7 Z9 7 U1 1 U2 9 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 OCT PY 2001 VL 58 IS 5 BP 1063 EP 1071 DI 10.1006/jmsc.2001.1092 PG 9 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 483NL UT WOS:000171641100015 ER PT J AU Ehrhardt, NM Legault, CM Restrepo, VR AF Ehrhardt, NM Legault, CM Restrepo, VR TI Density-dependent linkage between juveniles and recruitment for pink shrimp (Farfantepenaeus duorarum) in southern Florida SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE density-dependent recruitment; Florida Bay; pink shrimp ID BAY; FISHERY AB Pink shrimp (Farfantepenaeus duorarum) is an important commercial species in the eastern Gulf of Mexico. with annual landings between 2300 and 4500 metric tonnes during the past decade. The adults are exploited by a trawl fishery in the Dry Tortugas region, while juveniles inhabit Florida Bay. The onshore-offshore ontogenetic migrations create many opportunities for disruption of cohorts. Potential linkage between the abundance of juveniles in nursery areas and of recruits to the fishery was examined by relating recruitment success to juvenile density spanning 123 months of data. The fitted recruitment success model predicts well the general trend in the ratio of recruitment to juvenile density. However, the full magnitude of the expected trends is not fully explained by the model, and environmental variables on recruitment may have a sizeable effect. However. the density dependence of recruitment to the fishery on juvenile density is significant. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Biol & Fisheries, Miami, FL 33149 USA. Natl Marine Fisheries Serv, SE Fishery Sci Ctr, Miami, FL 33149 USA. Int Commiss Conservat Atlantic Tunas, Madrid 28002, Spain. RP Ehrhardt, NM (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Biol & Fisheries, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. NR 16 TC 5 Z9 5 U1 1 U2 6 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 OCT PY 2001 VL 58 IS 5 BP 1100 EP 1105 DI 10.1006/jmsc.2001.1101 PG 6 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 483NL UT WOS:000171641100019 ER PT J AU Snyder, CR Mopsik, FI AF Snyder, CR Mopsik, FI TI A precision capacitance cell for measurement of thin film out-of-plane expansion - Part III: Conducting and semiconducting materials SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE capacitance cell; coefficient of thermal expansion (CTE); guarded electrode; high sensitivity displacement; inner layer dielectrics; polymers; thin films ID THERMAL-EXPANSION; POLYMER-FILMS; SILICON AB This paper describes the construction, calibration, and use of a precision capacitance-based metrology for the measurement of the thermal and hygrothermal (swelling) expansion of thin films. It is demonstrated that with this version of our capacitance cell, materials ranging in electrical properties from insulators to conductors can be measured. The results of our measurements on p-type < 100 > -oriented single crystal silicon are compared to the recommended standard reference values from the literature and are shown to be in excellent agreement. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Snyder, CR (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RI Snyder, Chad/B-4957-2008 OI Snyder, Chad/0000-0002-2916-9809 NR 15 TC 1 Z9 1 U1 2 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD OCT PY 2001 VL 50 IS 5 BP 1212 EP 1215 DI 10.1109/19.963185 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 489NN UT WOS:000171997900031 ER PT J AU Paulter, NG Larson, DR AF Paulter, NG Larson, DR TI An examination of the spectra of the "kick-out" pulses for a proposed sampling oscilloscope calibration method SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE frequency spectra; kick-out pulse; nose-to-nose calibration method; offset voltage; pulse metrology; sampler calibration ID NOSE AB The spectra of the "kick-out" pulses used in a proposed sampler calibration method [1]-[3] were examined. The proposed calibration method requires that the amplitude of these pulses be linear with an adjustment parameter called the offset voltage. The kick-out pulses were observed to have a nonlinear dependence on offset voltage, and this may affect the application of the proposed calibration method. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM nicholas.paulter@nist.gov NR 6 TC 5 Z9 8 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9456 EI 1557-9662 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD OCT PY 2001 VL 50 IS 5 BP 1221 EP 1223 DI 10.1109/19.963187 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 489NN UT WOS:000171997900033 ER PT J AU Paulter, NG AF Paulter, NG TI An assessment on the accuracy of time-domain reflectometry for measuring the characteristic impedance of transmission lines SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE characteristic impedance; high speed/high frequency; impedance discontinuity; time-domain reflectometry; transmission line AB An assessment of time-domain reflectometry (TDR) for measuring the characteristic impedance Z(TL) of transmission lines is performed. The assessment includes the accuracy, of measuring Z(TL) as a function of TDR electrical impedance Z(O), the ability to measure impedance perturbations as a function Of Z(TL) and Z(O), and the ability to differentiate between transmission lines of similar Z(TL). The information presented herein will be especially useful for those using 50 Omega TDR systems to characterize transmission lines having characteristic impedances less than about 30 Omega. C1 US Dept Commerce, Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab,Technol Lab, Gaithersburg, MD 20899 USA. RP Paulter, NG (reprint author), US Dept Commerce, Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab,Technol Lab, Gaithersburg, MD 20899 USA. NR 5 TC 14 Z9 16 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD OCT PY 2001 VL 50 IS 5 BP 1381 EP 1388 DI 10.1109/19.963214 PG 8 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 489NN UT WOS:000171997900060 ER PT J AU Randa, J AF Randa, J TI Noise characterization of multiport amplifiers SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE amplifier noise; differential amplifier; multiport amplifier; noise; noise figure; noise matrix; thermal noise AB This paper addresses the issue of the definition and measurement of the noise figure and parameters to characterize multiport devices, particularly differential amplifiers. A parameterization in terms of the noise matrix appears to be the most practical. The noise figure for a given output port is defined and related to the noise matrix and scattering parameters of the device, as well as the correlations between different input noise waves. The degradation of the signal-to-noise ratio is obtained from a special choice of the input correlation function. Two examples are considered in detail: a three-port differential amplifier and a four-port mixed-mode amplifier, both with reflectionless terminations. The noise figures, effective input temperatures, and gains are related to the results of a series of hot-cold measurements, as in the familiar two-port case. C1 Natl Inst Stand & Technol, Radio Frequency Technol Div, Boulder, CO 80303 USA. RP Randa, J (reprint author), Natl Inst Stand & Technol, Radio Frequency Technol Div, 325 Broadway, Boulder, CO 80303 USA. NR 12 TC 31 Z9 32 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD OCT PY 2001 VL 49 IS 10 BP 1757 EP 1763 DI 10.1109/22.954781 PN 1 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA 480KK UT WOS:000171460400013 ER PT J AU Harnack, R Apffel, K Georgescu, M Baines, S AF Harnack, R Apffel, K Georgescu, M Baines, S TI The determination of observed atmospheric differences between heavy and light precipitation events in New Jersey, USA SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE heavy precipitation forecasting; New Jersey climate; quantitative precipitation forecasting; synoptic climatology ID UNITED-STATES; WARM-SEASON; RAINSTORMS; REGION AB The climatology of a limited sample of heavy precipitation events occurring in New Jersey, USA, is studied via statistical averaging and frequency histograms of environmental conditions at the event location. Also. the spatial distribution of related circulation features is examined. In addition, statistical differences between conditions accompanying the heavy (HEAVY) and a selected sample of light (LIGHT) precipitation events is determined. A large number of surface. standard level. stability and wind shear variables are employed as well as synoptic-scale circulation features. Variables that are identified as statistically significant, after a Student's t-test is applied to a sample mean and standard deviation are listed by season. In addition. scatter plot and composite maps are produced to illustrate conditions concurrent with the onset of heavy precipitation. In general, there are only slight differences between values obtained for the HEAVY sample and the LIGHT sample. However. the differences are large enough for some variables in some seasons that the forecaster may be able to use these results to advantage. In particular: (i) a significantly warmer and moister atmosphere at selected levels is indicated for the HEAVY sample for Autumn and Winter but not for Spring and Summer: (ii) upper-tropospheric divergence is significantly greater in all seasons except Summer: and (iii) wind shear is significantly larger in all seasons except Summer. There is much similarity in the mean position of examined synoptic features such as troughs, vorticity maxima, jet axes and jet streaks for the two samples. However, the amplitude of circulation in the troposphere is much larger for the HEAVY sample. especially in the lower troposphere. In addition. the 850-hPa wind maximum axis (low-level jet indication) is much more often oriented from south to north and located within 300 km of the event location for the HEAVY cases. There was surprisingly no significant sample difference found for static stability and precipitable water in any season. Based on the results reported here. the forecaster is particularly advised to examine the tropospheric circulation amplitude and the position of low and upper-level jet axes and jet streaks before forecasting heavy precipitation in the mid-Atlantic region of the USA. Copyright (C) 2001 Royal Meteorological Society. C1 Rutgers State Univ, Cook Coll, New Jersey Agr Expt Stn, Dept Environm Sci, New Brunswick, NJ 08901 USA. Caribou Natl Weather Serv Forecast Off, Natl Ocean & Atmospher Adm, Dept Commerce, Caribou, ME USA. Natl Weather Serv Forecast Off, Raleigh, NC USA. RP Harnack, R (reprint author), Rutgers State Univ, Cook Coll, New Jersey Agr Expt Stn, Dept Environm Sci, 14 Coll Farm Rd, New Brunswick, NJ 08901 USA. RI Georgescu, Matei/G-5442-2011 NR 18 TC 6 Z9 6 U1 0 U2 3 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 OCT PY 2001 VL 21 IS 12 BP 1529 EP 1560 DI 10.1002/joc.668 PG 32 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 488JP UT WOS:000171932300006 ER PT J AU Morrison, GC Howard, CJ AF Morrison, GC Howard, CJ TI Selective detection of gas-phase aldehydes and ketones using protonated hydrazine SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE gas phase ion chemistry; aldehyde and ketone detection; protonated hydrazine; plant emissions ID VOLATILE ORGANIC-COMPOUNDS; REACTION MASS-SPECTROMETRY; SIFT; AIR; O-2(+); SERIES; OZONE; TENAX; H3O+; NO+ AB This article reports the results of the gas phase studies of protonated hydrazine, N2H5+, reactions with different classes of organic compounds in a chemical ionization mass spectrometer (CIMS). We found that saturated aldehydes react with N2H5+, in the presence of a drift field and neutral hydrazine, to form primarily a protonated hydrazone, e.g. formaldehyde reacts to form CH2N2H3+. Unsaturated aldehydes, saturated ketones, and hydroxyl substituted carbonyl compounds react to form protonated hydrazones and association complexes, e.g. N2H5+. acetone. In the absence of a drift field, methanol, ethanol, and toluene react to form association complexes; otherwise, no reaction occurs. We propose a method of detecting gas-phase aldehydes and ketones using protonated hydrazine, N2H5+, as a reagent ion in a CIMS. The method was demonstrated by measuring three C-6 aldehydes released by grass that had been frozen, crushed and thawed. Qualitatively and quantitatively, the results compare favorably with the results of aldehyde emission experiments reported by others. (C) 2001 Elsevier Science B.V. C1 Univ Colorado, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80305 USA. RP Morrison, GC (reprint author), Univ Missouri, Dept Civil Engn, 119 A Butler Carlton Hall, Rolla, MO 65409 USA. RI Morrison, Glenn/B-4261-2016 OI Morrison, Glenn/0000-0001-6876-7185 NR 23 TC 11 Z9 11 U1 4 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD OCT 1 PY 2001 VL 210 IS 1-3 SI SI BP 503 EP 509 DI 10.1016/S1387-3806(01)00392-X PG 7 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 485FK UT WOS:000171742700044 ER PT J AU Martys, NS AF Martys, NS TI A classical kinetic theory approach to lattice Boltzmann simulation SO INTERNATIONAL JOURNAL OF MODERN PHYSICS C LA English DT Article DE BGK; complex fluids; computational fluid dynamics; kinetic theory; lattice Boltzmann; Navier-Stokes equation; phase transitions; porous media ID NAVIER-STOKES EQUATIONS; MODEL; FLOW; FLUIDS; MEDIA AB An approach to lattice Boltzmann simulation is described, which makes a direct connection between classical kinetic theory and contemporary lattice Boltzmann modeling methods. This approach can lead to greater accuracy, improved numerical stability and significant reductions in computational needs, while giving a new philosophical point of view to lattice Boltzmann calculations for a large range of applications. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Bldg Mat Div, Gaithersburg, MD 20899 USA. RP Martys, NS (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Bldg Mat Div, Gaithersburg, MD 20899 USA. NR 32 TC 8 Z9 8 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0129-1831 J9 INT J MOD PHYS C JI Int. J. Mod. Phys. C PD OCT PY 2001 VL 12 IS 8 BP 1169 EP 1178 DI 10.1142/S0129183101002474 PG 10 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 500EP UT WOS:000172613200004 ER PT J AU Dienstfrey, A Greengard, L AF Dienstfrey, A Greengard, L TI Analytic continuation, singular-value expansions, and Kramers-Kronig analysis SO INVERSE PROBLEMS LA English DT Article AB We describe a systematic approach to the recovery of a function analytic in the upper half-plane, C+, from measurements over a finite interval on the real axis, D subset of R. Analytic continuation problems of this type are well known to be ill-posed. Thus, the best one can hope for is a simple, linear procedure which exposes this underlying difficulty and solves the problem in a least-squares sense. To accomplish this, we first construct an explicit analytic approximation of the desired function and recast the continuation problem in terms of a 'residual function' defined on the measurement window D itself. The resulting procedure is robust in the presence of noise, and we demonstrate its performance with some numerical experiments. C1 NIST, Boulder, CO 80309 USA. NYU, Courant Inst, New York, NY USA. RP NIST, Boulder, CO 80309 USA. EM andrewd@boulder.nist.gov NR 10 TC 16 Z9 16 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0266-5611 EI 1361-6420 J9 INVERSE PROBL JI Inverse Probl. PD OCT PY 2001 VL 17 IS 5 BP 1307 EP 1320 DI 10.1088/0266-5611/17/5/305 PG 14 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 487HT UT WOS:000171869300005 ER PT J AU Crouch, DJ Cook, RF Trudeau, JV Dove, DC Robinson, JJ Webster, HL Fatah, AA AF Crouch, DJ Cook, RF Trudeau, JV Dove, DC Robinson, JJ Webster, HL Fatah, AA TI The detection of drugs of abuse in liquid perspiration SO JOURNAL OF ANALYTICAL TOXICOLOGY LA English DT Article C1 Univ Utah, Ctr Human Toxicol, Salt Lake City, UT 84112 USA. Inst Social Anal, Alexandria, VA USA. Washington Pretrial Serv Agcy, Washington, DC USA. Wescor Inc, Logan, UT USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Crouch, DJ (reprint author), Univ Utah, Ctr Human Toxicol, 20 S 2030 E Room 490, Salt Lake City, UT 84112 USA. NR 11 TC 4 Z9 5 U1 0 U2 0 PU PRESTON PUBLICATIONS INC PI NILES PA 7800 MERRIMAC AVE PO BOX 48312, NILES, IL 60648 USA SN 0146-4760 J9 J ANAL TOXICOL JI J. Anal. Toxicol. PD OCT PY 2001 VL 25 IS 7 BP 625 EP 627 PG 3 WC Chemistry, Analytical; Toxicology SC Chemistry; Toxicology GA 478JY UT WOS:000171344300024 PM 11599612 ER PT J AU Prudnikov, IR Matyi, RJ Deslattes, RD AF Prudnikov, IR Matyi, RJ Deslattes, RD TI Wavelet transform approach to the analysis of specular x-ray reflectivity curves SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ROUGH SURFACES; NEUTRON-SCATTERING; THIN-FILMS; MULTILAYERS; MONOLAYERS; SYSTEMS AB A method for analyzing x-ray reflectivity curves from multilayered structures with interfacial roughness using a wavelet transform approach has been developed. By using this approach, we have been able (1) to extract the contribution of a particular rough interface to a specular reflectivity curve, and (2) to determine the root-mean-square amplitude of the roughness of a particular interface independently of the other interfaces in the multilayered structure from the specular reflectivity data. Analytical procedures that allow the interpretation of the wavelet coefficients obtained from specular reflectivity curves have been developed. This approach has been successfully applied to experimental reflectivity curves obtained from Cu/Ta, Ta2O5/Ta, and Ta2O5/Ta2N bilayer structures. (C) 2001 American Institute of Physics. C1 Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. Moscow MV Lomonosov State Univ, Dept Phys, Moscow 119899, Russia. RP Prudnikov, IR (reprint author), Natl Inst Stand & Technol, Phys Lab, 100 Bur Dr,Stop 8422, Gaithersburg, MD 20899 USA. NR 29 TC 9 Z9 11 U1 0 U2 7 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 OCT 1 PY 2001 VL 90 IS 7 BP 3338 EP 3346 DI 10.1063/1.1399022 PG 9 WC Physics, Applied SC Physics GA 474YY UT WOS:000171135900031 ER PT J AU Fenves, SJ Rasdorf, WJ AF Fenves, SJ Rasdorf, WJ TI Role of ASCE in the advancement of computing in civil engineering SO JOURNAL OF COMPUTING IN CIVIL ENGINEERING LA English DT Article AB Computing has emerged as a major focus area in civil engineering, just as it has in other disciplines. This paper examines the role of the American Society of Civil Engineers (ASCE) in the advancement and development of this focus on computing in civil engineering. The paper documents the technical activities of ASCE that contributed to this evolution, particularly the committees of the Structural Division (now the Structural Engineering Institute) and the Technical Council on Computer Practices (now the Technical Council on Computing and Information Technology). Emphasis is placed on the initial activities and the current status of each group. A broad survey of ASCE activities that contribute to the dissemination of information on computing in civil engineering is presented. The role of ASCE publications in this effort is examined. The ASCE conferences and congresses on computing are documented and evaluated. Finally, observations are made about the society's overall impact on computing in civil engineering. C1 NIST, Gaithersburg, MD 20899 USA. N Carolina State Univ, Dept Civil Engn, Raleigh, NC 27695 USA. RP Fenves, SJ (reprint author), NIST, 100 Bur Dr,Build 304,Stop 8262, Gaithersburg, MD 20899 USA. NR 32 TC 5 Z9 5 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0887-3801 J9 J COMPUT CIVIL ENG JI J. Comput. Civil. Eng. PD OCT PY 2001 VL 15 IS 4 BP 239 EP 247 DI 10.1061/(ASCE)0887-3801(2001)15:4(239) PG 9 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA 476CV UT WOS:000171209400001 ER PT J AU Cherng, AM Chow, LC Takagi, S AF Cherng, AM Chow, LC Takagi, S TI In vitro evaluation of a calcium phosphate cement root canal filler/sealer SO JOURNAL OF ENDODONTICS LA English DT Article ID HYDROXYAPATITE CEMENT; DYE PENETRATION; SEALER-FILLER; IN-VITRO; RECONSTRUCTION; OBLITERATION; SURGERY; DEFECTS; TEETH AB An in vitro dye leakage study was performed to compare the apical leakage of a fill with injectable calcium phosphate cement (CPC) filler/sealer and a master silver cone with leakage from a fill of Sealapex sealer and laterally condensed gutta-percha. Ten instrumented, extracted, single-rooted human teeth were obturated with either laterally condensed gutta-percha and Sealapex as the sealer or with a single master cone and the CPC paste sealer. Additional teeth were included in the study to serve as controls. The teeth were placed in 1 % poly-R dye solution (pH 7.0) for 5 days. After the teeth were longitudinally sectioned apical leakage of dye was measured. There were no significant differences between the CPC and Sealapex groups. The single cone CPC procedure provided an adequate apical seal against dye penetration. Should retreatment become necessary the single cone may be removed to provide access for instrumentation. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. RP Cherng, AM (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. FU NIDCR NIH HHS [DE11789] NR 20 TC 25 Z9 26 U1 0 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0099-2399 J9 J ENDODONT JI J. Endod. PD OCT PY 2001 VL 27 IS 10 BP 613 EP 615 PG 3 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 476RU UT WOS:000171243200003 PM 11592489 ER PT J AU Link, JS Burnett, J AF Link, JS Burnett, J TI The relationship between stomach contents and maturity state for major northwest Atlantic fishes: new paradigms? SO JOURNAL OF FISH BIOLOGY LA English DT Article DE reproduction; feeding; spawning; iteroparous; ramper and rester paradigms ID PSEUDOPLEURONECTES-AMERICANUS; GASTEROSTEUS-ACULEATUS; WINTER FLOUNDER; EGG-PRODUCTION; FOOD-HABITS; GROWTH; GULF; STICKLEBACKS; POPULATION; ABUNDANCE AB Iteroparous species examined from the northwest Atlantic demonstrated distinct relationships between feeding and reproduction. Two species showed an increase in feeding during the developing, ripe and running stages of reproduction, indicative of the ramper pattern. Four species showed an increase in feeding after spawning in the spent or resting stage of reproduction, indicative of the rester pattern, Two species exhibited no distinct pattern. Evidence from other species confirms these major patterns. This information may be useful to determine the effectiveness of different management measures, particularly in relation to feeding or spawning aggregations. There are two major feeding-reproductive patterns for fishes along a continuum of possibilities. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Link, JS (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. NR 42 TC 16 Z9 16 U1 1 U2 6 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD OCT PY 2001 VL 59 IS 4 BP 783 EP 794 DI 10.1006/jfbi.2001.1687 PG 12 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 492XK UT WOS:000172192700002 ER PT J AU Smith, DA Roman, DR AF Smith, DA Roman, DR TI GEOID99 and G99SSS: 1-arc-minute geoid models for the United States SO JOURNAL OF GEODESY LA English DT Article DE geoid; GPS; Datums; reference systems; gravity; deflections of the vertical ID HEIGHT MODEL AB Two new geoid models have been computed for the United States and its territories. The first model is the purely gravimetric G99SSS model, approximating the geopotential surface W-0 = 62636856.88 m(2)/s(2) and referenced to the geocentric GRS-80 ellipsoid whose origin coincides with the ITRF96(1997.0) origin. The other model is the hybrid GEOID99 model, which encompasses all gravimetric information of G99SSS as well as the vertical datum information of 6169 GPS-derived NAD 83 (North American Datum 1983) ellipsoid heights co-located with spirit-leveled NAVD 88 (North American Vertical Datum 1988) Helmert orthometric heights. The coverage of both models in the conterminous United States (CONUS) is from 24 degreesN to 58 degreesN latitude and 230 degreesE to 300 degreesE longitude. Long-wavelength geoid structure was controlled by the EGM96 model coefficients, medium-scale information by 2.6 million gravity measurements, and local features through the use of 30-arc-second and (recently created) 3-arc-second digital elevation models. In addition to new elevation data, there were corrected errors in the old elevation data, better satellite altimetry data, and ellipsoidal corrections in G99SSS and GEOID99 that were not applied in G96SSS and GEOID96. The GEOID99 model replaces the GEOID96 model as the primary conversion surface between NAD 83 ellipsoid heights and NAVD 88 Helmert orthometric heights. While GEOID96 had the ability to convert absolute heights (of the 1996 GPS-on-bench-mark data set, or GPSBMs) at the +/-5.3-cm level, GEOID99 works with the latest GPSBMs at the +/-4.6-cm level. The improvement from 5.5 to 4.6 cm in RMS further translates into almost 2 cm of additional accuracy in single-tic differential GPS-based leveling over most short baselines. Of this 4.6 cm, some 2.0 to 2.5 cm is attributed to correlated errors in the gravimetric geoid and local GPS errors', decorrelating around 40 km. The GPS-derived ellipsoid heights in CONUS have changed since 1996 due to an increased number of observations and new adjustments of previously observed areas. This new GPS data is reflected in GEOID99, but not GEOID96, which effectively renders GEOID96 out of date (in an absolute sense), so that the absolute agreement between GEOID96 and the 1999 set of GPSBMs is only at the +/-6.5-cm level. In addition to the geoid models in CONUS, gravimetric geoid models were produced in Alaska., Hawaii, and Puerto Rico and the American Virgin Islands. Surface deflection of the vertical models were also computed and show agreement with astro-geodetically determined deflections below the I-arc-second level. C1 NOAA, Natl Geodet Survey, Silver Spring, MD 20910 USA. RP Smith, DA (reprint author), NOAA, Natl Geodet Survey, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 40 TC 37 Z9 41 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0949-7714 J9 J GEODESY JI J. Geodesy PD OCT PY 2001 VL 75 IS 9-10 BP 469 EP 490 DI 10.1007/s001900100200 PG 22 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 498BH UT WOS:000172489600002 ER PT J AU Fry, CD Sun, W Deehr, CS Dryer, M Smith, Z Akasofu, SI Tokumaru, M Kojima, M AF Fry, CD Sun, W Deehr, CS Dryer, M Smith, Z Akasofu, SI Tokumaru, M Kojima, M TI Improvements to the HAF solar wind model for space weather predictions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; MAGNETIC-FIELD; INTERPLANETARY MEDIUM; GEOMAGNETIC STORMS; SEMIANNUAL VARIATION; FLARE MYTH; DISTURBANCES; SPEED; PROPAGATION; SIMULATION AB We have assembled and tested, in real time, a space weather modeling system that starts at the Sun and extends to the Earth through a set of coupled, modular components. We describe recent efforts to improve the Hakamada-Akasofu-Fry (HAF) solar wind model that is presently used in our geomagnetic storm prediction system. We also present some results of these improvement efforts. In a related paper, Akasofu [2001] discusses the results of the first 2 decades using this system as a research tool and for space weather predictions. One key goal of our efforts is to provide quantitative forecasts of geoeffective solar wind conditions at the L1 satellite point and at Earth. Notably, we are addressing a key problem for space weather research: the prediction of the north-south component (B-z) of the interplanetary magnetic field. This parameter is important for the transfer of energy from the solar wind to the terrestrial environment that results in space weather impacts upon society. We describe internal improvements, the incorporation of timely and accurate boundary conditions based upon solar observations, and the prediction of solar wind speed, density, magnetic field, and dynamic pressure. HAF model predictions of shock arrival time at the L1 satellite location are compared with the prediction skill of the two operational shock propagation models: the interplanetary shock propagation model (ISPM) and the shocktime-of-arrival (STOA) model. We also show model simulations of shock propagation compared with interplanetary scintillation observations. Our modeling results provide a new appreciation of the importance of accurately characterizing event drivers and for the influences of the background heliospheric plasma on propagating interplanetary disturbances. C1 Explorat Phys Int Inc, Milford, NH 03055 USA. Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Alaska Fairbanks, Int Arctic Res Ctr, Fairbanks, AK 99775 USA. Nagoya Univ, Solar Terr Environm Lab, Aichi 442, Japan. RP Fry, CD (reprint author), Explorat Phys Int Inc, 614 Nashua St 222, Milford, NH 03055 USA. RI xue, yansheng/A-9712-2012 NR 57 TC 118 Z9 126 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 1 PY 2001 VL 106 IS A10 BP 20985 EP 21001 DI 10.1029/2000JA000220 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 475XG UT WOS:000171194600005 ER PT J AU Wright, JW Conkright, RO AF Wright, JW Conkright, RO TI Prospects for an ionospheric index of neutral thermospheric composition, with space-weather applications SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTRON-CONTENT; F-LAYER; PERTURBATIONS; NORTHERN AB We address the need for an easily observable indicator of thermospheric state, and particularly one sensitive to the neutral concentration ratio, [O]/[N-2]. Accepting foF2 as the observable of choice, several options for a derived thermospheric daily index are considered; these include midday and nighttime mean values of foF2(2), and others based on the rate of change offoF2(2) during sunrise, which might serve as indicators of [O]/[N-2]. We show the global morphology of a promising sunrise index over more than three solar cycles, derived from data in the National Geophysical Data Center Ionospheric Digital Database (NGDC/IDD) and similar databases. There are well-defined dependencies on solar activity, season, geography, and storm-disturbance level. We compare the indices to ESR04 satellite global observations of [O]/[N-2] and find correlation coefficients as low as 0.3 (southern winter) and as high as 0.8 (close passes, all data), depending upon hemisphere and season, satellite/ground-site proximity, satellite altitude, etc. Using median foF2(2) to compare our sunrise index to the Mass Spectrometer-Incoherent Scatter (MSIS-90) model atmosphere at a constant pressure level, we find similar latitude variations in three longitude sectors and two solar cycle extremes. A successful index of [O]/[N-2], available daily from monitoring ionosondes (and perhaps from Global Positioning System/Total Electron Content (GPS/TEC) monitors, derived similarly), would have important applications in aeronomy, space weather, and telecommunications forecasting. C1 NOAA, Natl Geophys Data Ctr, World Data Ctr Solar Terr Phys A, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, NGDC, Boulder, CO 80309 USA. RP Wright, JW (reprint author), NOAA, Natl Geophys Data Ctr, World Data Ctr Solar Terr Phys A, Room 507,325 Broadway, Boulder, CO 80303 USA. NR 19 TC 2 Z9 2 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 1 PY 2001 VL 106 IS A10 BP 21063 EP 21075 DI 10.1029/2000JA000215 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 475XG UT WOS:000171194600012 ER PT J AU Ohtani, S Nose, M Rostoker, G Singer, H Lui, ATY Nakamura, M AF Ohtani, S Nose, M Rostoker, G Singer, H Lui, ATY Nakamura, M TI Storm-substorm relationship: Contribution of the tail current to Dst SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; MAGNETOSPHERIC SUBSTORMS; RING CURRENT; GEOMAGNETIC DISTURBANCE; SYNCHRONOUS ORBIT; PHASE; DECAY; SATELLITE; DYNAMICS; ONSET AB The Dst index has been conventionally used as a measure of the storm intensity, which ideally assumes that the associated ground magnetic disturbance is caused by the ring current. The present study examines the contribution of the tail current to Dst, focusing on the occurrence of geosynchronous dipolarization close to the Dst minimum, in other words, the start of the storm recovery phase. The Sym-H (referred to as Dst((Sy-H)) hereafter) index rather than the conventional Dst index is used because of its higher time resolution (1 min). For the June 1998 storm event, dipolarization started at two GOES satellites and the Geotail satellite in the near-Earth tail when Dst((Sym-H)) reached its minimum. This result indicates that the source current was located outside of geosynchronous orbit, and therefore the recovery of Dst((Sym-H)) can be attributed to the reduction of the tail current rather than the decay of the ring current. A statistical study based on 59 storm events (79 GOES events) confirms the tendency for geosynchronous magnetic field to dipolarize at the Dst((Sym-H)) minimum. It is therefore highly likely that the Dst((Sym-H)) minimum is misidentified as the start of the ring current (storm) decay at a time when the ring current may actually be intensifying owing to substorm-associated injection, From the magnitude of the Dst((Sym-H)) recovery during the interval of geosynchronous dipolarization, the contribution of the tail current to Dst((Sym-H)) at the Dst((Sym-H)) minimum is estimated to be 20-25%. However, the contribution of the tail current may be even larger because the tail current may not return to preintensification levels and may continue to contribute to Dst(sym-fn after dipolarization. The trigger of dipolarization (substorm) and the subsequent recovery of Dst((Sym-H)) tend to take place in the course of the reduction of the southward interplanetary magnetic field (IMF) B-Z. It is therefore suggested that the ring current (storm) recovers after the substorm since the magnetospheric convection weakens because of weaker southward IMF B-Z. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Tokyo, Dept Earth & Planetary Sci, Tokyo 113, Japan. Nagoya Univ, Solar Terr Environm Lab, Toyokawa 442, Japan. NOAA, Boulder, CO 80303 USA. RP Ohtani, S (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. RI Nose, Masahito/B-1900-2015; Ohtani, Shinichi/E-3914-2016 OI Nose, Masahito/0000-0002-2789-3588; Ohtani, Shinichi/0000-0002-9565-6840 NR 28 TC 66 Z9 66 U1 0 U2 5 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 OCT 1 PY 2001 VL 106 IS A10 BP 21199 EP 21209 DI 10.1029/2000JA000400 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 475XG UT WOS:000171194600023 ER PT J AU Youd, TL Idriss, IM Andrus, RD Arango, I Castro, G Christian, JT Dobry, R Finn, WDL Harder, LF Hynes, ME Ishihara, K Koester, JP Liao, SSC Marcuson, WF Martin, GR Mitchell, JK Moriwaki, Y Power, MS Robertson, PK Seed, RB Stokoe, KH AF Youd, TL Idriss, IM Andrus, RD Arango, I Castro, G Christian, JT Dobry, R Finn, WDL Harder, LF Hynes, ME Ishihara, K Koester, JP Liao, SSC Marcuson, WF Martin, GR Mitchell, JK Moriwaki, Y Power, MS Robertson, PK Seed, RB Stokoe, KH TI Liquefaction resistance of soils: Summary report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils SO JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING LA English DT Article ID CONE PENETRATION TEST; SPT; EARTHQUAKES AB Following disastrous earthquakes in Alaska and in Niigata, Japan in 1964, Professors H. B. Seed and I. M. Idriss developed and published a methodology termed the "simplified procedure" for evaluating liquefaction resistance of soils. This procedure has become a standard of practice throughout North America and much of the world. The methodology which is largely empirical, has evolved over years, primarily through summary papers by H. B. Seed and his colleagues. No general review or update of the procedure has occurred, however, since 1985, the time of the last major paper by Professor Seed and a report from a National Research Council workshop on liquefaction of soils. In 1996 a workshop sponsored by the National Center for Earthquake Engineering Research (NCEER) was convened by Professors T. L. Youd and I. M. Idriss with 20 experts to review developments over the previous 10 years. The purpose was to gain consensus on updates and augmentations to the simplified procedure. The following topics were reviewed and recommendations developed: (1) criteria based on standard penetration tests; (2) criteria based on cone penetration tests; (3) criteria based on shear-wave velocity measurements, (4) use of the Becker penetration test for gravelly soil; (4) magnitude scaling factors; (5) correction factors for overburden pressures and sloping ground; and (6) input values for earthquake magnitude and peak acceleration. Probabilistic and seismic energy analyses were reviewed but no recommendations were formulated. C1 Brigham Young Univ, Provo, UT 84602 USA. Univ Texas, Austin, TX 78712 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Alberta, Edmonton, AB, Canada. Geomatrix Consultants, Oakland, CA 94612 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Univ So Calif, Los Angeles, CA 90089 USA. USA, Engineer Waterways Expt Stn, Vicksburg, MS 39180 USA. Parsons Brinckerhoff, Boston, MA 02116 USA. Univ Tokyo, Tokyo, Japan. Calif Dept Water Resour, Sacramento, CA 94236 USA. Univ British Columbia, Vancouver, BC V5Z 1M9, Canada. Rensselaer Polytech Inst, Troy, NY 12180 USA. GEI Consultants Inc, Winchester, MA 01890 USA. Bechtel Corp, San Francisco, CA 94119 USA. NIST, Gaithersburg, MD 20899 USA. Clemson Univ, Clemson, SC 29634 USA. Univ Calif Davis, Davis, CA 95616 USA. RP Youd, TL (reprint author), Brigham Young Univ, Provo, UT 84602 USA. NR 60 TC 509 Z9 540 U1 7 U2 87 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 1090-0241 J9 J GEOTECH GEOENVIRON JI J. Geotech. Geoenviron. Eng. PD OCT PY 2001 VL 127 IS 10 BP 817 EP 833 DI 10.1061/(ASCE)1090-0241(2001)127:10(817) PG 17 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA 476DB UT WOS:000171210000001 ER PT J AU Allen, MD Evenson, KM Brown, JM AF Allen, MD Evenson, KM Brown, JM TI High-resolution spectroscopic measurements of the nu(5) bending vibration-rotation band of HCCN in its (X)over-tilde(3)Sigma(-) state at 129 cm(-)1 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE FIR LMR; bending vibration-rotation transitions; quasilinear ID MAGNETIC-RESONANCE SPECTROSCOPY; GROUND-STATE; MICROWAVE SPECTROSCOPY; EQUILIBRIUM GEOMETRY; CYANOMETHYLENE HCCN; MOLECULES; CARBENE; QUASILINEARITY; CYANOCARBENE; NU(1)+NU(5) AB The HCCN radical is known to be a quasi-linear molecule in its ground triplet state ((3)Sigma (-) in the linear configuration). Vibration-rotation transitions in the HCC bending (nu (5)) fundamental band have been detected around 129 cm(-1) by the technique of far-infrared laser magnetic resonance (FIR LMR). Four FIR laser lines were used to record a total of 530 resonances. The observed transitions can be regarded equivalently as K-a = 1 <-- 0 transitions of a bent molecule or as l(s) = 1 <-- 0 transitions of a linear molecule. The LMR data, combined with previous measurements on this molecule at microwave and submillimeter wavelengths, have been used to determine parameters of an asymmetric rotor Hamiltonian. The nu (5) band origin has been determined more accurately as 128.907 968 7 (40) cm(-1). In addition, it has been possible to characterize the electron spin splittings in the K-a = 1 levels more reliably. Both H-1 and N-14 hyperfine splittings have been observed for the K-a = 1 levels for the first time; they show that the nuclear spin-electron spin dipolar interactions are markedly noncylindrical. Values for the electron spin and rotational g-factors (g(s)(alpha alpha) and g(r)(alpha alpha) have also been determined. (C) 2001 Academic Press. C1 Natl Inst Stand & Technol, Time & Frequency Div 847, Boulder, CO 80303 USA. Univ Oxford, Phys & Theoret Chem Lab, Oxford OX1 3QZ, England. RP Allen, MD (reprint author), Natl Inst Stand & Technol, Time & Frequency Div 847, 325 Broadway, Boulder, CO 80303 USA. NR 43 TC 15 Z9 15 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 OCT PY 2001 VL 209 IS 2 BP 143 EP 164 DI 10.1006/jmsp.2001.8387 PG 22 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 490JP UT WOS:000172049000001 ER PT J AU Maslar, JE Hurst, WS Bowers, WJ Hendricks, JH AF Maslar, JE Hurst, WS Bowers, WJ Hendricks, JH TI In situ Raman spectroscopic investigation of zirconium-niobium alloy corrosion under hydrothermal conditions SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID BOILING WATER-REACTOR; OXIDE-FILMS; STAINLESS-STEEL; TETRAGONAL ZIRCONIA; MODIFIED ZIRCALOY-4; AQUEOUS-SOLUTIONS; ALUMINUM-ALLOY; OXIDATION; CHROMIUM; SPECTRA AB In situ Raman spectroscopy was employed to investigate corrosion of a zirconium-niobium alloy in air-saturated water at a pressure of 15.5 MPa and temperatures ranging from 22 to 407 degreesC in an optically accessible flow cell. Monoclinic ZrO(2) (m-ZrO(2)) was identified under all conditions after the coupon was heated to 255 degreesC for 19 h. Cubic ZrO(2) (c-ZrO(2)) was tentatively identified in situ during heating at temperatures between 306 and 407 degreesC, but was not observed under any other conditions. Species tentatively identified as alpha -CrOOH and a Cr(VI) and/or Cr(III)/Cr(VI) compound were observed in situ during heating at temperatures between 255 and 407 degreesC but were not observed under any other conditions. The chromium compounds were identified as corrosion products released from the optical cell and/or flow system. Published by Elsevier Science B.V. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Maslar, JE (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, 100 Bur Dr,Stop 8360, Gaithersburg, MD 20899 USA. EM jmaslar@nist.gov NR 53 TC 22 Z9 23 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD OCT PY 2001 VL 298 IS 3 BP 239 EP 247 DI 10.1016/S0022-3115(01)00657-2 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 479AK UT WOS:000171381600004 ER PT J AU Ostrovsky, L Lebedev, A Matveyev, A Potapov, A Sutin, A Soustova, I Johnson, P AF Ostrovsky, L Lebedev, A Matveyev, A Potapov, A Sutin, A Soustova, I Johnson, P TI Application of three-dimensional resonant acoustic spectroscopy method to rock and building materials SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB This paper presents the experimental and theoretical results of applying resonant acoustic spectroscopy (RAS) to determine elastic parameters and losses in such consolidated granular materials as rock and building bricks. First, the theoretical aspects of the RAS method are outlined. A computer code for the rectangular and cylindrical samples was developed and tested. The results of experiments on specimens of rock and ceramic brick are then described. Finally, a modification of the previously published RUS algorithm is presented which permits a significant reduction in computing time for elongated samples. (C) 2001 Acoustical Society of America. C1 NOAA Environm Technol Lab, Zel Technol, Boulder, CO 80305 USA. Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603600, Russia. Los Alamos Natl Lab, Los Alamos, NM 87501 USA. RP Ostrovsky, L (reprint author), NOAA Environm Technol Lab, Zel Technol, 325 Broadway, Boulder, CO 80305 USA. OI Ostrovsky, Lev/0000-0003-2233-1305 NR 20 TC 14 Z9 16 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD OCT PY 2001 VL 110 IS 4 BP 1770 EP 1777 DI 10.1121/1.1402255 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 481NT UT WOS:000171526400014 PM 11681357 ER PT J AU Godin, OA Chapman, DMF AF Godin, OA Chapman, DMF TI Dispersion of interface waves in sediments with power-law shear speed profiles. I. Exact and approximate analytical results SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article; Proceedings Paper CT 139th Meeting of the Acoustical-Society-of-America CY MAY 30-JUN 03, 2000 CL ATLANTA, GEORGIA SP Acoustical Soc Amer ID MARINE-SEDIMENTS; VELOCITY; MODULUS AB In the upper tens of meters of ocean bottom, unconsolidated marine sediments consisting of clay, silt, or fine sand with high porosity are "almost incompressible" in the sense that the shear wave velocity is much smaller than the compressional wave velocity. The shear velocity has very large gradients close to the ocean floor leading to strong coupling of compressional and shear waves in such "soft" sediments. The weak compressibility opens an avenue for developing a theory of elastic wave propagation in continuously stratified soft sediments that fully accounts for the coupling. Elastic waves in soft sediments consist of "fast" waves propagating with velocities close to the compressional velocity and "slow" waves propagating with velocities on the order of the shear velocity. For the slow waves, the theory predicts the existence of surface waves at the ocean-sediment boundary. In the important special case of the power-law depth-dependence of shear rigidity, phase and group velocities of the interface waves are shown to scale as a certain power of frequency. An explicit, exact solution was obtained for the surface waves in sediments characterized by constant density and a linear increase of shear rigidity with depth, that is, for the case of shear speed proportional to the square root of the depth below the sediment-water interface. Asymptotic and perturbation techniques were used to extend the result to more general environments. Theoretical dispersion relations agreed well with numerical simulations and available experimental data and, as demonstrated in a companion paper [D. M. F. Chapman and O. A. Godin, J. Acoust. Soc. Am 110, 1908 (2001)] led to a simple and robust inversion of interface wave travel times for shear velocity profiles in the sediment. (C) 2001 Acoustical Society of America. C1 NOAA, Environm Technol Lab, Ocean Remote Sensing Div, Boulder, CO 80305 USA. Russian Acad Sci, PP Shirshov Oceanog Inst, Acoust Wave Propagat Lab, Moscow 117851, Russia. RP Godin, OA (reprint author), NOAA, Environm Technol Lab, Ocean Remote Sensing Div, Boulder, CO 80305 USA. RI Godin, Oleg/E-6554-2011 OI Godin, Oleg/0000-0003-4599-2149 NR 29 TC 25 Z9 26 U1 0 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 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD OCT PY 2001 VL 110 IS 4 BP 1890 EP 1907 DI 10.1121/1.1401776 PG 18 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 481NT UT WOS:000171526400027 PM 11681370 ER PT J AU Chapman, DMF Godin, OA AF Chapman, DMF Godin, OA TI Dispersion of interface waves in sediments with power-law shear speed profiles. II. Experimental observations and seismo-acoustic inversions SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article; Proceedings Paper CT 4th International Conference on Theoretical and Computational Acoustics (ICTCA) CY MAY 10-14, 1999 CL TRIESTE, ITALY ID MARINE-SEDIMENTS; REFLECTION; VELOCITY AB The propagation of seismic interface waves is investigated in soft marine sediments in which the density is constant, the shear modulus is small, and the profile of shear speed c, versus depth z is of the power-law form c(s)(z) = c(0)z(v), in which c(0) and v are constants (0 < V < 1). Both the phase speed V and the group speed U of interface waves scale with frequency as f(v/(v-1)) and they obey the simple relation U = (1 - v) V. These relations are derived in a simple way using ray theory and the WKB method; a companion paper [O. A. Godin and D. M. F. Chapman, J. Acoust. Soc. Am. 110, 1890 (2001)] rigorously derives the same result from the solutions to the equations of motion. The frequency scaling is shown to exist in experimental data sets of interface wave phase speed and cr group speed. Approximate analytical formulas for the dispersion relations (phase and group speed versus frequency) enable direct inversion of the profile parameters co and v from the experimental data. In cases for which there is multi-mode dispersion data, the water-sediment density ratio can be determined as well. The theory applies to vertically polarized (P-SV) modes as well as to horizontally polarized (SH) modes (that is, Love waves). (C) 2001 Acoustical Society of America. C1 Def Res Estab Atlantic, Dartmouth, NS B2Y 3Z7, Canada. NOAA, Environm Technol Lab, Ocean Remote Sensing Div, Boulder, CO 80303 USA. Russian Acad Sci, PP Shirshov Oceanog Inst, Acoust Wave Propagat Lab, Moscow 117851, Russia. RP Def Res Estab Atlantic, POB 1012, Dartmouth, NS B2Y 3Z7, Canada. EM chapman@drea.dnd.ca RI Godin, Oleg/E-6554-2011 OI Godin, Oleg/0000-0003-4599-2149 NR 24 TC 22 Z9 22 U1 0 U2 3 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 EI 1520-8524 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD OCT PY 2001 VL 110 IS 4 BP 1908 EP 1916 DI 10.1121/1.1401739 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 481NT UT WOS:000171526400028 PM 11681371 ER PT J AU Hermann, AM Wang, YT Ramakrishnan, PA Balzar, D An, LN Haluschka, C Riedel, R AF Hermann, AM Wang, YT Ramakrishnan, PA Balzar, D An, LN Haluschka, C Riedel, R TI Structure and electronic transport properties of Si-(B)-C-N ceramics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 2nd International Workshop on Ultrahigh Temperature Polymer Derived Ceramics CY JUL 23-29, 2000 CL BOULDER, COLORADO ID SILICON CARBONITRIDE; HIGH-TEMPERATURE; POLYSILAZANES; VISCOSITY AB The structure and electronic transport properties of polymer-derived pristine and boron-doped silicon carbonitride ceramics have been studied, with particular emphasis on understanding the effect of annealing treatments. Structural analysis using the radial distribution function formalism showed that the local structure is comprised of basic building blocks of Si tetrahedra with B, C, and N at the corners. Comparison of the electrical properties of pristine and boron-doped ceramics shows that boron doping leads to enhanced p-type conductivity, with a small positive thermopower. The postpyrolysis annealing treatments at elevated temperatures have a significant effect on the conductivity. The conductivity variation with temperature for these ceramics shows Mott's variable range hopping (VRH) behavior, characteristic of a highly defective semiconductor. C1 Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80303 USA. Univ Cent Florida, Dept Mech Mat & Aerosp Engn, Orlando, FL 32726 USA. Tech Univ Darmstadt, Fachgebiet Disperse Feststoffe, Fachbereich Mat Wissensch, D-64287 Darmstadt, Germany. RP Hermann, AM (reprint author), Univ Colorado, Dept Phys, Boulder, CO 80309 USA. NR 16 TC 53 Z9 54 U1 7 U2 19 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 OCT PY 2001 VL 84 IS 10 BP 2260 EP 2264 PG 5 WC Materials Science, Ceramics SC Materials Science GA 483KM UT WOS:000171634600020 ER PT J AU Black, D AF Black, D TI Strength-limiting surface damage in single-crystal sapphire imaged by X-ray topography SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SUBSURFACE DAMAGE AB X-ray topography was used in an effort to understand the relationship between microstructure and fracture strength in single-crystal sapphire bend bars. The bars were indistinguishable using standard optical characterization techniques, but X-ray diffraction topography revealed that they could be separated into two distinct types. The first type had an oriented microstructure consisting of a pattern of linear features parallel to the long axis of the bars. This microstructure was attributed to fabrication damage. The second type was well-polished, nearly damage-free sapphire. Fracture strength data showed that the damaged bars had strengths less than 70% of the bars without damage. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Black, D (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 17 TC 5 Z9 6 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 2001 VL 84 IS 10 BP 2351 EP 2355 PG 5 WC Materials Science, Ceramics SC Materials Science GA 483KM UT WOS:000171634600034 ER PT J AU Kim, HW Deng, Y Miranda, P Pajares, A Kim, DK Kim, HE Lawn, BR AF Kim, HW Deng, Y Miranda, P Pajares, A Kim, DK Kim, HE Lawn, BR TI Effect of flaw state on the strength of brittle coatings on soft substrates SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SHARP CONTACT CRACKING; FRACTURE-MECHANICS; LAYER STRUCTURES; TRAPPED CRACKS; INDENTATION; DAMAGE; CERAMICS; GLASS; INTERLAYER; TOUGHNESS AB A study is made of the role of flaw state on the strength properties of brittle ceramic coating layers bonded to soft polycarbonate substrates. We introduce Vickers radial cracks at prescribed loads into the coating undersurfaces prior to bonding to control the sizes and locations of the starting flaws. A spherical indenter is then loaded on the top bilayer surfaces, directly above the Vickers indentation sites, subjecting the radial cracks to flexural tensile stress. Radial crack responses are monitored in situ, using a camera located below the transparent substrate. Critical loads to cause radial crack instability, and ensuing growth of the arrested cracks, are recorded. Conventional biaxial flexure tests on corresponding monolith coating materials provide a baseline for data comparison. Relative to the monolith flexure specimens, the bilayers show higher strengths, the more so the larger the flaw, indicating enhanced flaw tolerance. A simple fracture mechanics analysis of the radial crack evolution in the concentrated-load field, with due account for distribution of flexural tensile stresses at the coating undersurface, is unable to account completely for the enhanced bilayer strengths for the larger Vickers flaws. It is hypothesized that the epoxy used to bond the bilayer components enters the cracks, causing crack-wall adherence and providing an increased resistance to radial crack instability. The fracture mechanics are nevertheless able to account for the arrest and subsequent stable extension of the radial cracks beyond the critical loads once this extraneous adherence has been overcome. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Kim, HW (reprint author), Seoul Natl Univ, Sch Mat Sci & Engn, Seoul 151742, South Korea. RI Miranda, Pedro/C-4465-2008; Pajares, Antonia/I-3881-2015; Kim, Do Kyung/C-2039-2011 OI Miranda, Pedro/0000-0003-4348-110X; Pajares, Antonia/0000-0002-1086-7586; Kim, Do Kyung/0000-0001-9092-9427 NR 29 TC 57 Z9 58 U1 2 U2 8 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 OCT PY 2001 VL 84 IS 10 BP 2377 EP 2384 PG 8 WC Materials Science, Ceramics SC Materials Science GA 483KM UT WOS:000171634600039 ER PT J AU Krause, RF Wiederhorn, SM AF Krause, RF Wiederhorn, SM TI Tensile creep behavior of a gas-pressure-sintered silicon nitride containing silicon carbide SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 102nd Annual Meeting of the American-Ceramic-Society CY MAY 01-02, 2000 CL ST LOUIS, MISSOURI SP Amer Ceram Soc ID STRESS RUPTURE BEHAVIOR; NANOCOMPOSITE MATERIALS; PERFORMANCE; COMPONENTS; CERAMICS; STRENGTH AB The tensile creep behavior of a gas-pressure-sintered silicon nitride containing silicon carbide was characterized at temperatures between 1375 degrees and 1450 degreesC with applied stresses between 50 and 250 MPa. Individual specimens were tested at fixed temperatures and applied loads. Each specimen was pin-loaded within the hot zone of a split-tube furnace through silicon carbide rods connected outside the furnace to a pneumatic cylinder. The gauge length was measured by laser extensometry, using gauge markers attached to the specimen. Secondary creep rates ranged from 0.54 to 270 Gs(-1), and the creep tests lasted from 6.7 to 1005 h. Exponential functions of stress and temperature were fitted to represent the secondary creep rate and the creep lifetime. This material was found to be more creep resistant than two other silicon nitride ceramics that had been characterized earlier by the same method of measurement as viable candidates for high-temperature service. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Honeywell Technol Ctr, Morristown, NJ 07962 USA. RP Krause, RF (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 28 TC 4 Z9 4 U1 0 U2 4 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 2001 VL 84 IS 10 BP 2394 EP 2400 PG 7 WC Materials Science, Ceramics SC Materials Science GA 483KM UT WOS:000171634600041 ER PT J AU Hildmann, B Ledbetter, H Kim, S Schneider, H AF Hildmann, B Ledbetter, H Kim, S Schneider, H TI Structural control of elastic constants of mullite in comparison to sillimanite SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CRYSTAL-STRUCTURE; THERMAL-EXPANSION; SPECTROSCOPY; RESONANCE; DIFFRACTION; ULTRASOUND; MODES AB Nine elastic stiffness coefficients, c(ij), of a mullite single crystal (2Al(2)O(3)(.)SiO(2)) are measured using acoustic resonance spectroscopy. The obtained values are similar to those of the structurally related aluminosilicate phase sillimanite ((Al2O3SiO2)-Si-.)(.) Characteristic elastic properties of the two minerals are interpreted with the help of their crystal structures and atomic force constants for sillimanite. The high longitudinal stiffness coefficients, c(33), of mullite (similar to 352 GPa) and sillimanite (similar to 388 GPa) are caused by continuous "stiff" load-bearing tetrahedral chains parallel to c-axis, while the "soft" octahedral chains have minor direct influence. They stabilize the tetrahedal chains against tilting. The lower c(33) value of mullite in comparison to the sillimanite value may be caused by a weakening of the load-bearing tetrahedral chains which are parallel to c-axis because of partial replacement of silicon by the weaker-bonded aluminum. The longitudinal stiffness coefficients perpendicular to c-axis are significantly lower, because of sequences of alternating "soft" octahedral and "stiff" tetrahedral units. Within the plane (001), the compliant octahedra exhibit stiffness-controlling influence with coefficients parallel to b-axis (c(22) approximate to 233 GPa) being somewhat lower than parallel to a-axis (c(11) approximate to 291 GPa). This is explained with the occurrence of compliant octahedral Al(1)-O(D) bonds, which are more effective parallel to b-axis rather than to a-axis. Because octahedra are unaffected by the aluminum to silicon substitution, c(11) and c(22) coefficients of mullite and sillimanite are very similar. Shear stiffness coefficients of mullite increase from c(55) (similar to 77 GPa) to c(66) (similar to 80 GPa) to c(44) (similar to 110 GPa), indicating increasing resistance against shear deformation within the planes (010), (001), and (100). The lattice plane of the highest shear stiffness (100) is built up of an oxygen-oxygen network, diagonally braced along < 011 > ("Jagerzaun"). This network with short oxygen-oxygen distances can be sheared by compression and elongation along oxygen-oxygen interaction lines only which is rather unlikely. Because of the lack of such networks in the planes (010) and (001), bending and deformation of structural units become easier, and consequently c(55) and c(66) are 15 degrees /sec, appeared to be foraging or social dives. Simple dives that did not include convoluted movements (angular velocity <10/sec) were considered to be exploration dives. Directional dives with nearly linear horizontal travel (horizontal directionality >0.6, on a scale of 0-1) were presumed to be travel dives. Each three-dimensional dive type was observed with similar frequency in dives with two distinct time-depth profiles: V-shaped profiles in which ascent immediately followed descent, and U-shaped profiles in which >7 sec were spent at depth between descent and ascent. The lack of behavioral differences between dives with distinct time-depth profiles suggested that time-depth profiles are not a reliable means of inferring dive behaviors for ringed seals. C1 Univ Alaska Fairbanks, Inst Marine Sci, Fairbanks, AK 99775 USA. Univ Alaska, SFOS, Juneau Ctr Fisheries & Ocean Sci, Juneau, AK 99801 USA. Univ Missouri, Grad Sch, St Louis, MO 63121 USA. RP Simpkins, MA (reprint author), Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 44 TC 11 Z9 12 U1 1 U2 7 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD OCT PY 2001 VL 17 IS 4 BP 909 EP 925 DI 10.1111/j.1748-7692.2001.tb01305.x PG 17 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 486GC UT WOS:000171809200014 ER PT J AU Heide-Jorgensen, MP Kleivane, L Oien, N Laidre, KL Jensen, MV AF Heide-Jorgensen, MP Kleivane, L Oien, N Laidre, KL Jensen, MV TI A new technique for deploying satellite transmitters on baleen whales: Tracking a blue whale (Balaenoptera musculus) in the North Atlantic SO MARINE MAMMAL SCIENCE LA English DT Article ID MONITORED MOVEMENTS; FEEDING SEASON; FALL MIGRATION C1 Inst Marine Res, N-5817 Bergen, Norway. Greenland Inst Nat Resources, Nuuk 3900, Greenland. RP Heide-Jorgensen, MP (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. EM MadsPeter.Heide-Joergensen@noaa.gov NR 12 TC 30 Z9 32 U1 2 U2 15 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD OCT PY 2001 VL 17 IS 4 BP 949 EP 954 DI 10.1111/j.1748-7692.2001.tb01309.x PG 6 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 486GC UT WOS:000171809200018 ER PT J AU Moore, SE Urban, J Perryman, WL Gulland, F Perez-Cortes, H Wade, PR Rojas-Bracho, L Rowles, T AF Moore, SE Urban, J Perryman, WL Gulland, F Perez-Cortes, H Wade, PR Rojas-Bracho, L Rowles, T TI Are gray whales hitting "K" hard? SO MARINE MAMMAL SCIENCE LA English DT Article C1 NOAA, Natl Marine Fisheries Serv, AFSC, Natl Marine Mammal Lab, Seattle, WA 98115 USA. Univ Autonoma Baja California, Dept Biol Marina, La Paz 23081, Baja California, Mexico. NOAA, SWFSC, NMFS, La Jolla, CA 92038 USA. Marine Mammal Ctr, Sausalito, CA 94965 USA. CRIP, Inst Nacl Pesca, La Paz 23020, Baja California, Mexico. CICESE, Programa Nacl Invest & Conservac Mamiferos Marino, Ensenada 22860, Baja California, Mexico. NOAA, NMFS, Silver Spring, MD 20910 USA. RP Moore, SE (reprint author), NOAA, Natl Marine Fisheries Serv, AFSC, Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 10 TC 23 Z9 31 U1 0 U2 5 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD OCT PY 2001 VL 17 IS 4 BP 954 EP 958 DI 10.1111/j.1748-7692.2001.tb01310.x PG 5 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 486GC UT WOS:000171809200019 ER PT J AU Chopra, HD Hicho, GE Swartzendruber, LJ AF Chopra, HD Hicho, GE Swartzendruber, LJ TI Review of the jumpsum based nondestructive testing method for evaluating mechanical properties of ferromagnetic materials SO MATERIALS EVALUATION LA English DT Review DE barkhausen effect; jumpsum method; hysteresis loop; ultra low carbon steel; nondestructive testing; mechanical properties; magnetic properties ID BARKHAUSEN NOISE; STEEL AB This article is an overview of the jumpsum method for testing, in a nondestructive manner, the mechanical properties of ferromagnetic materials. The jumpsum method is a magnetic based method, which expresses and analyzes the barkhausen spectrum in terms of its profile rather than assigning the spectrum a mean or root mean square value. The jumpsum methodology allows unambiguous predictions of the mechanical properties of ferromagnetic materials over a wide range, including its ability to detect very small strains that are well below the 0.2 percent offset strain. Micromagnetics of the barkhausen spectrum and hysteresis loops are also discussed. C1 SUNY Buffalo, Dept Mech & Aerosp Engn, Thin Films & Nanosynth Lab, Mat Program, Buffalo, NY 14260 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Chopra, HD (reprint author), SUNY Buffalo, Dept Mech & Aerosp Engn, Thin Films & Nanosynth Lab, Mat Program, Buffalo, NY 14260 USA. NR 28 TC 6 Z9 6 U1 0 U2 1 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 OCT PY 2001 VL 59 IS 10 BP 1215 EP 1222 PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA 479TJ UT WOS:000171419400005 ER PT J AU Sekerka, RF Coriell, SR McFadden, GB AF Sekerka, RF Coriell, SR McFadden, GB TI Separation of scales for growth of an alloy needle crystal SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID DENDRITE C1 Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Carnegie Mellon Univ, Dept Math Sci, Pittsburgh, PA 15213 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sekerka, RF (reprint author), Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 8 TC 1 Z9 1 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD OCT PY 2001 VL 32 IS 10 BP 2669 EP 2670 DI 10.1007/s11661-001-0059-0 PG 2 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 480FN UT WOS:000171451500028 ER PT J AU DeLorenzo, ME Lewitus, AJ Scott, GI Ross, PE AF DeLorenzo, ME Lewitus, AJ Scott, GI Ross, PE TI Use of metabolic inhibitors to characterize ecological interactions in an estuarine microbial food web SO MICROBIAL ECOLOGY LA English DT Article ID BACTERIOPLANKTON PRODUCTION; PLANKTON COMMUNITY; AMINO-ACIDS; PHYTOPLANKTON; NITROGEN; BACTERIA; WATER; LOOP; GLUCOSE; GROWTH AB Understanding microbial food web dynamics is complicated by the multitude of competitive or interdependent trophic interactions involved in material and energy flow. Metabolic inhibitors can be used to gain information on the relative importance of trophic pathways by uncoupling selected microbial components and examining the net effect on ecosystem structure and function. A eukaryotic growth inhibitor (cycloheximide), a prokaryotic growth inhibitor (antibiotic mixture), and an inhibitor of photosynthesis (DCMU) were used to examine the trophodynamics of microbial communities from the tidal creek in North Inlet, a salt marsh estuary near Georgetown, South Carolina. Natural microbial communities were collected in the spring, summer, and fall after colonization onto polyurethane foam substrates deployed in the tidal creek. Bacterial abundance and productivity, heterotrophic ciliate and flagellate abundance, and phototrophic productivity, biomass, and biovolume were measured at five time points after inhibitor additions. The trophic responses of the estuarine microbial food web to metabolic inhibitors varied with season. In the summer, a close interdependency among phototrophs, bacteria, and protozoa was indicated, and the important influence of microzooplanktonic nutrient recycling was evident (i.e., a positive feedback loop). In the fall, phototroph and bacteria interactions were competitive rather than interdependent, and grazer nutrient regeneration did not appear to be an important regulatory factor for bacterial or phototrophic activities. The results indicate a seasonal shift in microbial food web structure and function in North Inlet, from a summer community characterized by microbial loop dynamics to a more linear trophic system in the fall. This study stresses the important role of microbial loops in driving primary and secondary production in estuaries such as North Inlet that are tidally dominated by fluctuations in nutrient supply and a summer phytoplankton bloom. C1 NOAA, US Dept Commerce, Coastal Ctr Environm Hlth & Biomol Res, Natl Ocean Serv, Charleston, SC 29412 USA. Univ S Carolina, Baruch Marine Lab, Belle W Baruch Inst Marine Biol & Coastal Res, Georgetown, SC 29442 USA. Marine Resources Res Inst, SC Dept Nat Resources, Charleston, SC 29412 USA. Colorado Sch Mines, Environm Sci & Engn Div, Golden, CO 80401 USA. RP DeLorenzo, ME (reprint author), NOAA, US Dept Commerce, Coastal Ctr Environm Hlth & Biomol Res, Natl Ocean Serv, Charleston, SC 29412 USA. EM marie.delorenzo@noaa.gov NR 48 TC 11 Z9 12 U1 4 U2 20 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0095-3628 J9 MICROB ECOL JI Microb. Ecol. PD OCT PY 2001 VL 42 IS 3 BP 317 EP 327 DI 10.1007/s00248-001-0004-1 PG 11 WC Ecology; Marine & Freshwater Biology; Microbiology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Microbiology GA 488WZ UT WOS:000171961000011 ER PT J AU Spencer, PL Doswell, CA AF Spencer, PL Doswell, CA TI A quantitative comparison between traditional and line integral methods of derivative estimation SO MONTHLY WEATHER REVIEW LA English DT Article ID OBJECTIVE ANALYSIS SCHEME; RADAR DATA; DIVERGENCE; DISCRETE; ERRORS AB For diagnostic purposes, the "traditional" approach to estimating derivatives employs objective analysis to provide a gridded field from the original observations, which are typically not uniformly distributed in space. However, there exist other methods involving derivative estimation via line integral ("triangle") techniques that do not involve a prior mapping of the field onto a uniform grid. It has been suggested that these give improved results. Empirical testing of the differences between wind field derivative estimation using two different schemes is done with prototypical examples of the techniques. Test results, verify that the triangle method indeed provides substantial improvements over the traditional scheme. The magnitude of the improvement is shown to depend on the degree of irregularity of the data distribution, as expected, Although the particular prototype methods chosen have the property that the triangle method truncates the amplitude of the input field slightly more than the traditional scheme, the pattern of the field is significantly better using the triangle technique than with the traditional method. An unexpected result is that the improvement by the triangle method over the traditional approach does not diminish as the wavelength of the input field increases. It is shown that this is a consequence of overfitting of the field to the station observations, causing local discontinuities in the field that produce errors in the gradient calculations, even in situations where the distribution of data is uniform. Overall, the test results make it abundantly clear that the traditional method is generally inferior to derivative estimates via the line integral methodology. C1 NOAA, OAR, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP Spencer, PL (reprint author), NOAA, OAR, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. RI Doswell III, Charles/E-7662-2010 NR 22 TC 11 Z9 12 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 OCT PY 2001 VL 129 IS 10 BP 2538 EP 2554 DI 10.1175/1520-0493(2001)129<2538:AQCBTA>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 474VP UT WOS:000171127800005 ER PT J AU Hirschberg, PA Shafran, PC Elsberry, RL Ritchie, EA AF Hirschberg, PA Shafran, PC Elsberry, RL Ritchie, EA TI An observing system experiment with the West Coast picket fence SO MONTHLY WEATHER REVIEW LA English DT Article ID ETA-MODEL; ADAPTIVE OBSERVATIONS; SINGULAR VECTORS; FASTEX; NCEP; SENSITIVITY; PREDICTION; PROJECT; SCHEME AB Analyses and forecasts from a modern data assimilation and modeling system are used to evaluate the impact of a special rawinsonde dataset of 3-h soundings at seven sites interspersed with the seven regular sites along the West Coast (to form a so-called picket fence to intercept all transiting circulations) plus special 6-h rawin-sondes over the National Weather Service Western Region. Whereas four intensive observing periods (IOPs) are available, only two representative IOPs (IOP-3 and IOP-4) are described here. The special observations collected during each 12-h cycle are analyzed with the National Centers for Environmental Prediction (NCEP) Eta Data Assimilation System in a cold start from the NCEP-National Center for Atmospheric Research reanalyses as the initial condition. Forecasts up to 48 h with and without the special picket fence observations are generated by the 32-km horizontal resolution Eta Model with 45 vertical levels. The picket fence observations had little impact in some cases with smooth environmental flow. In other cases, relatively large initial increments were introduced offshore of the picket fence observations. However, these increments usually damped as they translated downstream. During IOP-3, the increments amplified east of the Rocky Mountains after only 24 h. Even though initially small, the increments in IOP-4 grew rapidly to 500-mb height increments similar to 20-25 m with accompanying meridional wind increments of 5-8 m s(-1) that contributed to maxima in shear vorticity. Many of the downstream amplifying circulations had associated precipitation increments similar to6 mm (6 h)(-1) between the control and experimental forecasts. The equitable threat scores against the cooperative station set for the first 24-h forecasts during IOP-3 had higher values at the 0.50- and 0.75-in-thresholds for the picket fence dataset. However, the overall four-IOP equitable threat scores were similar. Although the classical synoptic case was not achieved during the picket fence, these model forecasts suggest that such observations around the coast of the United States would impact the downstream forecasts when added in dynamically unstable regions. An ultimate picket fence of continuous remotely observing systems should be studied further. C1 USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. Natl Weather Serv, Silver Spring, MD 20910 USA. Natl Ctr Environm Predict, Camp Springs, MD USA. RP Elsberry, RL (reprint author), USN, Postgrad Sch, Dept Meteorol, Code MR-Es,589 Dyer Rd,Room 254, Monterey, CA 93943 USA. RI Ritchie, Elizabeth/B-4232-2016 OI Ritchie, Elizabeth/0000-0002-3413-5830 NR 35 TC 3 Z9 3 U1 0 U2 2 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 OCT PY 2001 VL 129 IS 10 BP 2585 EP 2599 DI 10.1175/1520-0493(2001)129<2585:AOSEWT>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 474VP UT WOS:000171127800008 ER PT J AU Kuno, M Fromm, DP Gallagher, A Nesbitt, DJ Micic, OI Nozik, AJ AF Kuno, M Fromm, DP Gallagher, A Nesbitt, DJ Micic, OI Nozik, AJ TI Fluorescence intermittency in single InP quantum dots SO NANO LETTERS LA English DT Article ID CDSE/CDS CORE/SHELL NANOCRYSTALS; ROOM-TEMPERATURE; JUMPS; MOLECULES; BLINKING; PHOTOLUMINESCENCE; SPECTROSCOPY; INTENSITY; DYNAMICS; BEHAVIOR AB Fluorescence "blinking" kinetics of isolated colloidal InP quantum dots (QDs) are investigated via confocal single molecule microscopy. Analysis of fluorescence trajectories reveals inverse power law behavior (proportional to 1/tau(m)) in on/off time probability densities with m(on) approximate to 2.0(2) and m(off) approximate to 1.5(1). Such an inverse power law in both on/off times is inconsistent with a static distribution of electron/hole trapping sites and highlights the role of fluctuations in the OD nanoenvironment. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Nesbitt, DJ (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Kuno, Masaru/K-2673-2012; Nozik, Arthur/A-1481-2012; Nozik, Arthur/P-2641-2016 NR 37 TC 82 Z9 82 U1 1 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD OCT PY 2001 VL 1 IS 10 BP 557 EP 564 DI 10.1021/nl010049i PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 519JG UT WOS:000173721600009 ER PT J AU Perry, DM Mercaldo-Allen, R Burgh, S AF Perry, DM Mercaldo-Allen, R Burgh, S TI Growth and culture of larval and juvenile tautogs in a closed recirculating-seawater system SO NORTH AMERICAN JOURNAL OF AQUACULTURE LA English DT Article ID ONITIS AB Field-captured and laboratory-held adult tautogs Tautoga onitis were allowed to spawn naturally under laboratory conditions. Embryos were cultured to hatching and raised successfully through the larval stage to 490-d-old posthatch juveniles. A large (8,500-L), closed, recirculating-seawater system, designed with a biological filter containing air diffusers that passed a strong air-water mixture through a high-surface-area substrate, was used to culture the larvae and juveniles. The biological filter provided biofiltration, aeration, de-gassing, and foam fractionation without disturbing the larvae. Water quality measures within the system were maintained at acceptable values. Enrichment of rotifers and brine shrimp Artemia sp. with algal strains containing highly unsaturated fatty acids, plus wild zooplankton, provided an adequate diet for larval growth. Also, a commercial feed was given at 2 weeks and larval tautogs were observed eating it. Juvenile tautogs were fed enriched adult brine shrimp along with wild zooplankton and increasingly larger sizes If a commercial feed every 4-7 weeks. At 23 weeks of age, live foods were discontinued and the fish received only commercial feed for the remainder of the study. These feeds provided adequate diets for growth through the larval and juvenile stages. Growth in the length of the juvenile tautogs was linear from 172 to 490 d of age. The estimated growth rate, based on direct measurements of growth, was 0.29 mm/d, which is similar to the rates reported for other laboratory-reared juvenile tautogs and for other labrids. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Milford Lab, Milford, CT 06460 USA. RP Perry, DM (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Milford Lab, 212 Rogers Ave, Milford, CT 06460 USA. NR 23 TC 4 Z9 4 U1 0 U2 4 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 1522-2055 J9 N AM J AQUACULT JI N. Am. J. Aqualcult. PD OCT PY 2001 VL 63 IS 4 BP 300 EP 305 DI 10.1577/1548-8454(2001)063<0300:GACOLA>2.0.CO;2 PG 6 WC Fisheries SC Fisheries GA 485YB UT WOS:000171790100007 ER PT J AU Kitching, J Hollberg, L Knappe, S Wynands, R AF Kitching, J Hollberg, L Knappe, S Wynands, R TI Frequency-dependent optical pumping in atomic A-systems SO OPTICS LETTERS LA English DT Article ID SPECTROSCOPY AB We consider the effects of optical pumping on the conversion of laser-frequency modulation into intensity modulation by an atomic absorption line in a vapor of alkali atoms driven in a A-configuration. It is found that, due to optical pumping in combination with the excited-state hyperfine structure, the absorption line shape is distorted substantially as the Fourier frequency of the FM is changed. The most significant effect of the distortion is a shift of the apparent line center, which depends on how the frequency of the modulation compares with the optical pumping rate. This shift has implications for locking lasers to atomic transitions and also for FM-AM noise conversion in atomic vapors. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Bonn, Inst Angew Phys, D-53115 Bonn, Germany. RP Kitching, J (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, MS 847-10,325 Broadway, Boulder, CO 80303 USA. NR 14 TC 8 Z9 9 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD OCT 1 PY 2001 VL 26 IS 19 BP 1507 EP 1509 DI 10.1364/OL.26.001507 PG 3 WC Optics SC Optics GA 475PR UT WOS:000171173700016 PM 18049650 ER PT J AU Matsumoto, K Lynch-Stieglitz, J Anderson, RF AF Matsumoto, K Lynch-Stieglitz, J Anderson, RF TI Similar glacial and Holocene Southern Ocean hydrography SO PALEOCEANOGRAPHY LA English DT Article ID ANTARCTIC CIRCUMPOLAR CURRENT; OXYGEN ISOTOPIC COMPOSITION; DEEP-WATER CIRCULATION; VOSTOK ICE CORE; BENTHIC FORAMINIFERA; ATLANTIC SECTOR; ATMOSPHERIC CO2; SURFACE WATERS; CARBON-CYCLE; SEA-ICE AB We present new Holocene and glacial delta (18)O data measured on planktonic foraminifera Neogloboquadrina pachyderma and benthic foraminifera Cibicidoides species from the Atlantic and Pacific sectors of the Southern Ocean in order to better understand its glacial hydrography. Combined with previously published data, the latitudinal delta (18)O distributions of these foraminifera show no appreciable difference during the Holocene and the Last Glacial Maximum. This suggests that the basic Southern Ocean hydrography, including stratification and the mean position of the Antarctic Circumpolar Current frontal system, remained largely unchanged, although the small number of Pacific data render any conclusion in that sector preliminary. C1 Columbia Univ, Lamont Doherty Geol Observ, Palisades, NY 10964 USA. Columbia Univ, Dept Earth & Environm Sci, Palisades, NY 10964 USA. RP Matsumoto, K (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, POB CN710,Sayre Hall, Princeton, NJ 08544 USA. EM kmatsumo@splash.princeton.edu; jean@ldeo.columbia.edu; boba@ldeo.columbia.edu OI Anderson, Robert/0000-0002-8472-2494; Lynch-Stieglitz, Jean/0000-0002-9353-1972 NR 84 TC 30 Z9 30 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD OCT PY 2001 VL 16 IS 5 BP 445 EP 454 DI 10.1029/2000PA000549 PG 10 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA 473WW UT WOS:000171072800001 ER PT J AU Bryant, GW Jaskolski, W AF Bryant, GW Jaskolski, W TI Designing quantum dots and quantum-dot solids SO PHYSICA E LA English DT Article; Proceedings Paper CT Rutherford Memorial Workshop on Semiconductor Nanostructures CY FEB 05-09, 2001 CL QUEENSTOWN, NEW ZEALAND SP USAF Off Sci Res, Asian Off Aerosp Res & Dev, USN, Off Naval Res Int Field Off, USA Res Off Far E, Japan Soc Promot Sci, 151st Comm Nanometre Struct & Electr, Royal Soc New Zealand, Elsevier Sci, Keithley Instruments, Air New Zealand DE quantum dots; tight binding theory; heteronanostructures ID CDS/HGS/CDS; WELLS; PHOTOPHYSICS; COLLOIDS; CDS AB To design nanocrystal nanosystems, a theory for nanocrystals is needed which can be applied to nanocrystals with atomic-scale variations in composition, structure and shape. We present an empirical tight-binding theory for nanocrystal heteronanostructures. Electronic structure and optical absorption spectra are obtained for CdS/HgS/CdS and ZnS/CdS/ZnS quantum-dot quantum-well barrier/well/barrier nanocrystals. Comparison with experiment shows that tight-binding theory provides a good description of nanosystems with monolayer variations in composition. Well/barrier and well/barrier/well nanocrystal heteronanostructures also are modeled to illustrate state and energy-level engineering in nanocrystal nanosystems. (C) 2001 Elsevier Science B.V. All rights reserved. C1 NIST, Atom Phys Div, Gaithersburg, MD 20899 USA. UMK, Inst Fiz, Torun, Poland. RP Bryant, GW (reprint author), NIST, Atom Phys Div, Bldg 221,A267, Gaithersburg, MD 20899 USA. RI Jaskolski, Wlodzimierz/D-1318-2014 OI Jaskolski, Wlodzimierz/0000-0003-4814-1876 NR 14 TC 15 Z9 15 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1386-9477 J9 PHYSICA E JI Physica E PD OCT PY 2001 VL 11 IS 2-3 BP 72 EP 77 DI 10.1016/S1386-9477(01)00179-5 PG 6 WC Nanoscience & Nanotechnology; Physics, Condensed Matter SC Science & Technology - Other Topics; Physics GA 485HC UT WOS:000171746600006 ER PT J AU Durr, S AF Durr, S TI Quantitative wave-particle duality in multibeam interferometers SO PHYSICAL REVIEW A LA English DT Article ID WHICH-WAY INFORMATION; QUANTUM ERASURE; ATOM INTERFEROMETER; STATE DETERMINATION; FRINGE VISIBILITY; COMPLEMENTARITY AB We propose quantitative measures of wave properties and particle properties for multibeam interferometers. We show that these quantities are connected by a few fundamental inequalities which express wave-particle duality. Our analysis includes which-way detection schemes and quantum erasure. The inequalities derived here are a generalization of similar limits which were studied previously in the special case of two-beam interferometers. In addition, we propose alternative measures that express the available information more efficiently, and we show that these measures fulfill similar inequalities. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Durr, S (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RI Durr, Stephan/C-3760-2017 OI Durr, Stephan/0000-0003-0811-6211 NR 20 TC 31 Z9 31 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 OCT PY 2001 VL 64 IS 4 AR 042113 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 482ZU UT WOS:000171609900021 ER PT J AU Leo, PJ Venturi, V Whittingham, IB Babb, JF AF Leo, PJ Venturi, V Whittingham, IB Babb, JF TI Ultracold collisions of metastable helium atoms SO PHYSICAL REVIEW A LA English DT Article ID CLOSE-COUPLED CALCULATION; POLARIZED TRIPLET HELIUM; PHOTON RECOIL ENERGY; MAGNETOOPTICAL TRAP; HE ATOMS; COLD; BEAM; IONIZATION; FIELD; S-3) AB We report scattering lengths for the (1)Sigma (+)(g), (3)Sigma (+)(u), and (5)Sigma (+)(g) adiabatic molecular potentials relevant to collisions of two metastable 2 S-3 helium atoms as a function of the uncertainty in these potentials. These scattering lengths are used to calculate experimentally observable scattering lengths, elastic cross sections, and inelastic rates for any combination of states of the colliding atoms. at temperatures where the Wigner threshold approximation is valid. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. James Cook Univ N Queensland, Sch Math & Phys Sci, Townsville, Qld 4811, Australia. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Leo, PJ (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Leo, Paul/B-3470-2011 OI Leo, Paul/0000-0001-8325-4134 NR 44 TC 23 Z9 23 U1 2 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2001 VL 64 IS 4 AR 042710 DI 10.1103/PhysRevA.64.042710 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 482ZU UT WOS:000171609900064 ER PT J AU Stone, MB Zaliznyak, I Reich, DH Broholm, C AF Stone, MB Zaliznyak, I Reich, DH Broholm, C TI Frustration-induced two-dimensional quantum disordered phase in piperazinium hexachlorodicuprate SO PHYSICAL REVIEW B LA English DT Article ID SINGLET-GROUND-STATE; INELASTIC-NEUTRON-SCATTERING; GAP SYSTEM TLCUCL3; MAGNETIC EXCITATIONS; SPIN-GAP; TRIANGULAR-LATTICE; HEISENBERG-ANTIFERROMAGNET; LOW-TEMPERATURES; KAGOME-LATTICE; SQUARE-LATTICE AB Piperazinium hexachlorodicuprate is shown to be a frustrated quasi-two-dimensional quantum Heisenberg antiferromagnet with a gapped spectrum. Zero-field inelastic neutron scattering and susceptibility and specific-heat measurements as a function of applied magnetic field are presented. At T=1.5 K, the magnetic excitation spectrum is dominated by a single propagating mode with a gap, Delta =I meV, and bandwidth of approximate to1.8 meV in the (h01) plane. The mode has no dispersion along the b* direction indicating that neighboring a-c planes of the triclinic structure are magnetically decoupled. The heat capacity shows a reduction of the gap as a function of applied magnetic field in agreement with a singlet-triplet excitation spectrum. A field-induced ordered phase is observed in heat capacity and magnetic susceptibility measurements for magnetic fields greater than H-c1 approximate to7.5 T. Analysis of the neutron-scattering data reveals the important exchange interactions and indicates that some of these are highly frustrated. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Stone, MB (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RI Broholm, Collin/E-8228-2011; Stone, Matthew/G-3275-2011; Zaliznyak, Igor/E-8532-2014 OI Broholm, Collin/0000-0002-1569-9892; Stone, Matthew/0000-0001-7884-9715; Zaliznyak, Igor/0000-0002-9886-3255 NR 44 TC 51 Z9 51 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2001 VL 64 IS 14 AR 144405 DI 10.1103/PhysRevB.64.144405 PG 10 WC Physics, Condensed Matter SC Physics GA 481QC UT WOS:000171530000046 ER PT J AU Mark, T Ferguson, E Crutzen, P AF Mark, T Ferguson, E Crutzen, P TI Werner Lindinger - Obituary SO PHYSICS TODAY LA English DT Biographical-Item C1 Inst Ion Phys, Innsbruck, Austria. NOAA, Boulder, CO USA. Max Planck Inst Chem, D-55128 Mainz, Germany. RP Mark, T (reprint author), Inst Ion Phys, Innsbruck, Austria. RI Crutzen, Paul/F-6044-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 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 OCT PY 2001 VL 54 IS 10 BP 91 EP 91 PG 1 WC Physics, Multidisciplinary SC Physics GA 476HA UT WOS:000171219100027 ER PT J AU Coursey, BM McLaughlin, WL AF Coursey, BM McLaughlin, WL TI Wilfrid Basil Mann - Obituary SO PHYSICS TODAY LA English DT Biographical-Item C1 NIST, Gaithersburg, MD 20899 USA. RP Coursey, BM (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 1 TC 0 Z9 0 U1 0 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 OCT PY 2001 VL 54 IS 10 BP 92 EP 92 DI 10.1063/1.1420572 PG 1 WC Physics, Multidisciplinary SC Physics GA 476HA UT WOS:000171219100028 ER PT J AU Wang, ZG Wang, XH Hsiao, BS Andjelic, S Jamiolkowski, D McDivitt, J Fischer, J Zhou, J Han, CC AF Wang, ZG Wang, XH Hsiao, BS Andjelic, S Jamiolkowski, D McDivitt, J Fischer, J Zhou, J Han, CC TI Time-resolved isothermal crystallization of absorbable PGA-co-PLA copolymer by synchrotron small-angle X-ray scattering and wide-angle X-ray diffraction SO POLYMER LA English DT Article DE PGA-co-PLA; absorbable polymer; lamellar ID ETHER KETONE) PEEK; HYDROLYTIC DEGRADATION; POLY(GLYCOLIC ACID); POLYPROPYLENE; POLY(ETHYLENE-TEREPHTHALATE); POLY(GLYCOLIDE-CO-LACTIDE); POLYETHYLENE; POLYMERS; INVITRO; STATE AB The isothermal crystallization behavior of absorbable dyed and undyed PGA-co-PLA copolymers was investigated by time-resolved simultaneous small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) methods with synchrotron radiation. The morphological parameters extracted from time-resolved SAXS profiles show that long period and lamellar thickness decrease slightly after primary crystallization. The unit cell parameters a and b and the apparent lateral crystal sizes L-110 and L-020 were extracted from the corresponding WAXD profiles. A significant decrease in the unit cell parameters and a substantial increase in the apparent crystal sizes are seen during the initial crystallization stage. Both scattering invariant (Q from SAXS) and crystallinity (X-c from WAXD) results indicate that the crystallization rate is the fastest at 130 degreesC. These copolymers show a bell-shape crystallization rate curve with temperature, where the dyed copolymer has a faster crystallization rate than the undyed one even though the inclusion of the low molecular weight organic dye is very small (ca. 0.2% by weight). We conclude that the dye molecule, which enhances the visibility during surgery, acts as a nucleating agent that increases the overall crystallization rate. The crystallization rate at 90 degreesC is significantly slower than that at 130 degreesC, however, the long period and lamellar thickness formed at 90 degreesC are much lower than those formed at higher temperatures. The dyed and undyed PGA-co-PLA copolymers have almost the same morphological parameters at the same temperature. This indicates that morphological parameters of the lamellar structures in the polymers depend primarily on the crystallization temperature rather than on the crystallization rate. It is evident that the thermodynamic factor driven by temperature principally determines the lamellar morphology. The final unit cell parameters a and b and the final apparent crystal sizes all increase with temperature, indicating that crystal perfection prevails at high temperatures. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Ethicon Inc, Johnson & Johnson Co, Somerville, NJ 08876 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Hsiao, BS (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RI Wang, Zhigang/F-6136-2010 NR 34 TC 21 Z9 21 U1 1 U2 13 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD OCT PY 2001 VL 42 IS 21 BP 8965 EP 8973 DI 10.1016/S0032-3861(01)00374-3 PG 9 WC Polymer Science SC Polymer Science GA 458VY UT WOS:000170217200059 ER PT J AU Zhang, YM Li, W Tang, B Ge, S Hu, X Rafailovich, MH Sokolov, JC Gersappe, D Peiffer, DG Li, Z Dias, AJ McElrath, KO Lin, MY Satija, SK Urquhart, SG Ade, H AF Zhang, YM Li, W Tang, B Ge, S Hu, X Rafailovich, MH Sokolov, JC Gersappe, D Peiffer, DG Li, Z Dias, AJ McElrath, KO Lin, MY Satija, SK Urquhart, SG Ade, H TI Interfacial properties of elastomer blends as studied by neutron reflectivity SO POLYMER LA English DT Article DE polyolephin copolymers; polymer blends; polymer interfaces ID COMPATIBILIZED PVC/SBR BLENDS; POLYMER BLENDS; CROSS-LINKING; X-RAY; MISCIBILITY; COPOLYMERS; DIFFUSION; BEHAVIOR; MODEL AB The interfacial properties of a homopolymer (polybutadiene (PB)) and a terpolymer (brominated poly(isobutylene-co-p-methylstyrene) (BIMS)) are reported. Neutron reflectivity was used to study the interfacial structure. The results were complemented by scanning transmission X-ray microscopy and atomic force microscopy, which were used to probe the morphology of these binary blends. Our results show that the interfacial behavior of these elastomeric blends is a direct function of the BIMS chemical composition. The interfacial width decreased with increasing bromide functionality. At levels below 8 mol%, the para-methylstyrene concentration had a less pronounced effect on the compatibility and interfacial characteristics. We also studied the effect of styrene butadiene random copolymers on the miscibility of the PB/BIMS blends. The results showed that styrene-butadiene rubber (SBR) was not fully miscible with BIMS and PB on an individual basis, but addition of relatively small amount of SBR enhances the compatibilization of the PB/BIMS interface. Self-consistent field (SCF) modeling was used to determine the optimum copolymer composition. The calculations are consistent with the experimental results. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Exxon Res & Engn Co, Annandale, NJ 08801 USA. SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. RP Peiffer, DG (reprint author), Exxon Res & Engn Co, Route 22 E, Annandale, NJ 08801 USA. RI Ade, Harald/E-7471-2011; Urquhart, Stephen/A-6237-2014 OI Urquhart, Stephen/0000-0002-6415-6341 NR 29 TC 4 Z9 5 U1 1 U2 13 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD OCT PY 2001 VL 42 IS 21 BP 9133 EP 9141 DI 10.1016/S0032-3861(01)00370-6 PG 9 WC Polymer Science SC Polymer Science GA 458VY UT WOS:000170217200075 ER PT J AU Howard, L Stone, J Fu, J AF Howard, L Stone, J Fu, J TI Real-time displacement measurements with a Fabry-Perot cavity and a diode laser SO PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY LA English DT Article DE diode laser; nanometrology; Fabry-Perot interferometer; optical mixing errors; optical heterodyne frequency measurement; microwave frequency counter; AFM ID FREQUENCY-MODULATION SPECTROSCOPY; UPDATED EDLEN EQUATION; REFRACTIVE-INDEX; NANO-METROLOGY; CALIBRATION; STABILIZATION; AIR AB We present the basic operating principles of a traceable measurement system suitable for use with atomic force microscopes (AFMs) and nanometer-resolution displacement sensors. Our method is based upon a tunable external-cavity diode laser system which is servo-locked via a phase-modulated heterodyne locking technique to a Fabry-Perot interferometer cavity. We discuss mechanical considerations for the use of this cavity as a displacement metrology system and we describe methods for making real-time (sub 10 ms sampling period) measurements of the optical heterodyne signals. Our interferometer system produces a root-mean-squared (RMS) displacement measurement resolution of 20 pm. Two applications of the system are described. First, the system was used to examine known optical mixing errors in a heterodyne Michelson interferometer. Second, the Fabry-Perot interferometer was integrated into the Z axis of a commercial AFM scanning stage and used to produce interferometer-based images of a 17 nm step height specimen. We also demonstrate atomic resolution interferometer-based images of a 0.3 nm silicon single atomic step-terrace specimen. (C) 2001 Elsevier Science Inc. All rights reserved. C1 NIST, Div Precis Engn, Gaithersburg, MD 20899 USA. RP Stone, J (reprint author), NIST, Div Precis Engn, 100 Bur Dr,Mail Stop 8212, Gaithersburg, MD 20899 USA. NR 22 TC 33 Z9 34 U1 0 U2 11 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. Int. Soc. Precis. Eng. Nanotechnol. PD OCT PY 2001 VL 25 IS 4 BP 321 EP 335 DI 10.1016/S0141-6359(01)00086-1 PG 15 WC Engineering, Multidisciplinary; Engineering, Manufacturing; Nanoscience & Nanotechnology; Instruments & Instrumentation SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation GA 475DW UT WOS:000171147600010 ER PT J AU Minciarelli, F Gioffre, M Grigoriu, M Simiu, E AF Minciarelli, F Gioffre, M Grigoriu, M Simiu, E TI Estimates of extreme wind effects and wind load factors: influence of knowledge uncertainties SO PROBABILISTIC ENGINEERING MECHANICS LA English DT Article; Proceedings Paper CT Conference on Monte Carlo Simulation CY JUN 18-21, 2000 CL MONTE CARLO, MONACO DE building technology; hurricanes; load factors; Monte Carlo simulation; reliability; structural engineering; wind effects AB We propose a probabilistic methodology for developing improved load factors in standard provisions for wind loads, and use it to examine: the cause of the discrepancy noted in the 1980s between estimates of safety indices for wind and gravity loads; the relative magnitude of load factors for hurricane and non-hurricane regions; and the effect of the length of wind tunnel pressure records on the estimation of peak wind effects. According to our calculations, (1) the discrepancy between estimates of safety indices for gravity and wind loads is an artifact that can be removed by using current knowledge on probability distributions of extreme wind speeds; (2) the disregard in the ASCE 7-98 Standard of (a) knowledge uncertainties, and (b) errors inherent in the limited number of climatological data on which hurricane wind speed simulations are based, leads to incorrect wind load factor estimates; and (3) increasing beyond 30 min or even 20 min the length of pressure records used for the estimation of fluctuation peaks appears to have a relatively small effect on estimates of overall wind effects. We outline future research on wind directionality, sampling errors in the estimation of peak wind effects, and the use of probabilistic descriptions of wind effects and structural capacity to estimate probabilities of occurrence of nonlinear limit states, including structural collapse. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Univ Perugia, I-06100 Perugia, Italy. Cornell Univ, Ithaca, NY 14853 USA. RP Simiu, E (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Bldg 226, Gaithersburg, MD 20899 USA. NR 14 TC 27 Z9 28 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-8920 J9 PROBABILIST ENG MECH JI Probab. Eng. Eng. Mech. PD OCT PY 2001 VL 16 IS 4 BP 331 EP 340 DI 10.1016/S0266-8920(01)00024-8 PG 10 WC Engineering, Mechanical; Mechanics; Statistics & Probability SC Engineering; Mechanics; Mathematics GA 490LP UT WOS:000172053600009 ER PT J AU Wadso, I Goldberg, RN AF Wadso, I Goldberg, RN TI Standards in isothermal microcalorimetry (IUPAC technical report) SO PURE AND APPLIED CHEMISTRY LA English DT Article ID ETHANOL + WATER; EXCESS-ENTHALPIES; 15 MPA; TITRATION CALORIMETER; THERMAL-ANALYSIS; SYSTEM; CALIBRATION; POLYMORPHS; HYDROLYSIS; CONSTANTS AB The main calorimetric principles used in isothermal microcalorimetry are briefly discussed. Different chemical calibration and test reactions are discussed, with a focus on reactions suitable for ambient conditions: reactions initiated by mixing of liquids (including titration microcalorimetry), dissolution of solid compounds and of slightly soluble gases, a photochemical process, and thermal power signals released over an extended period of time. Guidelines on the use of standardized chemical test and calibration reactions in isothermal microcalorimetry are presented. A standardized terminology in reporting characteristics of isothermal microcalorimeters is proposed. C1 Lund Univ, Ctr Chem, S-22100 Lund, Sweden. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Wadso, I (reprint author), Lund Univ, Ctr Chem, POB 124, S-22100 Lund, Sweden. NR 50 TC 200 Z9 208 U1 4 U2 33 PU INT UNION PURE APPLIED CHEMISTRY PI RES TRIANGLE PK PA 104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USA SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD OCT PY 2001 VL 73 IS 10 BP 1625 EP 1639 DI 10.1351/pac200173101625 PG 15 WC Chemistry, Multidisciplinary SC Chemistry GA 510ZA UT WOS:000173236400009 ER PT J AU Mapes, BE AF Mapes, BE TI Water's two height scales: The moist adiabat and the radiative troposphere SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE gross moist stability; radiative-convective equilibrium; tropical atmosphere; vertical structure ID MESOSCALE CONVECTIVE SYSTEMS; TOGA-COARE; TROPICAL ATMOSPHERE; ENSEMBLE MODEL; ENERGY BUDGET; EQUILIBRIUM; INSTABILITY; CIRCULATIONS; TROPOPAUSE; CLIMATE AB The temperature structure of the tropical troposphere resembles a moist adiabat, with a lapse-rate transition toward dry adiabatic where water becomes scarce at an altitude H-ma similar to 8 km (350 hPa). Infrared emission by water vapour cools a deeper layer, extending up to H-rad similar to 14 km (160 hPa). Five consequences of these unequal heights are reviewed. 1. Upper-tropospheric relative humidity is often low, highly variable, and bimodal, due to the rapidity of drying by radiative subsidence. 2. Large-scale divergent circulations (e.g. equatorial v wind) exhibit a two-celled vertical structure, with an elevated convergence layer near 8-10 km in the rising branch. 3. The dominant deep convective heating process chances from latent heating at low levels to eddy heat-flux convergence in the upper troposphere. This requires a substantial updraught-environment temperature difference, which leads to large entrainment near H-ma, yielding stratiform anvil clouds which also contribute radiative heating. 4. The rising, branches of deep (similar toH(rad)) vertical circulations export more heat than they import as moisture, so that large-scale tropical dynamics can be characterized by a 'gross moist stability'. 5. Divergent motions with a vertical wavelength similar to8 km, corresponding to Kelvin or gravity wave speeds of similar to 15 m s(-1), are excited by simple (e.g. uniform) heating profiles extending through the lapse-rate change near H-ma. C1 NOAA, CIRES Climate Diagnost Ctr, Boulder, CO 80303 USA. RP Mapes, BE (reprint author), NOAA, CIRES Climate Diagnost Ctr, R-CDC 325 Broadway, Boulder, CO 80303 USA. RI Mapes, Brian/A-5647-2010 NR 47 TC 37 Z9 37 U1 2 U2 8 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD OCT PY 2001 VL 127 IS 577 BP 2353 EP 2366 DI 10.1256/smsqj.57707 PN A PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 487TC UT WOS:000171890500007 ER PT J AU Errico, RM Stensrud, DJ Raeder, KD AF Errico, RM Stensrud, DJ Raeder, KD TI Estimation of the error distributions of precipitation produced by convective parametrization schemes SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE convective precipitation; data assimilation; model error ID NUMERICAL WEATHER PREDICTION; MESOSCALE MODEL; ASSIMILATION; PARAMETERIZATION; SIMULATION; TESTS AB If a parametrization scheme for convective precipitation is to be used for assimilating observations of precipitation using a statistically based technique, then statistics of the errors produced by that scheme are required. These are the errors produced by the scheme's formulation itself, not counting any errors in the scheme's input, Such errors are extremely difficult to estimate, but examination of differences produced by various suitable schemes can yield qualitative descriptions of such errors. Here, hourly accumulated convective precipitation fields produced from six different versions of a short-term forecast model are compared. The versions have identical initial and boundary conditions, but vary in the schemes used for either the convection or the planetary boundary layer, or both. The distribution of differences, or differences in logarithms of accumulations, between corresponding precipitating grid points for pairs of forecasts are examined using a simple binning technique. When the convection schemes differ, results reveal that if either a log-normal or normal distribution is a better characterization of the distributions, it is the log-normal one. The standard deviations of these logarithmic distributions correspond to different schemes at identical grid points producing values differing by factors of 2 or more. A large proportion of grid points that have non-zero hourly accumulations using one model version may have no accumulation using another version, For most pairs of forecasts examined, however, grid points having larger values of accumulation for one scheme tend to have a smaller fraction of values having no accumulation in the other scheme. These results suggest that the finite probability that the model produces no precipitation when the corresponding, true atmospheric state does, should be considered in the statistical description of the model errors and that, because of the large standard deviation of model errors as well as large possible errors of hourly precipitation observations, the quantitative usefulness of assimilating such observations may be very limited. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Natl Severe Storms Lab, Norman, OK 73069 USA. RP Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM rmerrico@ucar.edu NR 27 TC 15 Z9 15 U1 0 U2 1 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0035-9009 EI 1477-870X J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD OCT PY 2001 VL 127 IS 578 BP 2495 EP 2512 DI 10.1256/smsqj.57801 PN B PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 500DX UT WOS:000172611600001 ER PT J AU Romero, R AF Romero, R TI Sensitivity of a heavy-rain-producing western Mediterranean cyclone to embedded potential-vorticity anomalies SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE heavy rain; potential-vorticity inversion ID CONVECTIVE ADJUSTMENT SCHEME; NUMERICAL SIMULATIONS; EXTRATROPICAL CYCLOGENESIS; DIAGNOSIS; SPAIN; INVERSION; SYSTEM; MODEL; EVENT; WAVE AB The development and track of a surface cyclone that produced heavy precipitation in the western Mediterranean region on 28-29 September 1994 is numerically simulated using a mesoscale model. Diagnostic calculations reveal that surface-pressure falls-and upward motion-occur in response to a well-defined pattern of upward quasi-geostrophic forcing at all tropospheric levels. In addition, convective instability and low-tropospheric water vapour flux convergence are significant over the western Mediterranean, and therefore the environment is highly supportive for convection development. The appreciable dynamical forcing at upper levels appears to be associated with two positive potential-vorticity (PV) anomalies that are embedded within the large-scale trough and rotate about each other. Motivated by the fact that the small-scale features of the PV field are more prone to analysis or forecast error than the large-scale components, a sensitivity study is conducted in order to analyse the dependence of the mesoscale forecast on the initial intensity and position of the two embedded PV centres. This is accomplished by first applying a piecewise PV-inversion technique which allows the balanced flow associated with each PV centre to be calculated, and then the inverted mass and wind fields are used to modify the model initial conditions. Eight simulations are run after doubling or removing one or both anomalies (sensitivity to intensity), and eight other simulations after displacing the anomalies towards or away from the Iberian peninsula (sensitivity to position). The results exhibit a clear dependence of the track and shape of the surface cyclone and its associated pattern of low-tropospheric warm air advection on the characteristics of the PV anomalies. Therefore, spatial details of the mesoscale forecast are shown to be highly sensitive to the precise structure of the upper-level dynamic forcing. Nevertheless, for the full set of arbitrarily defined initial conditions, one or several low pressure systems develop in the western Mediterranean area and heavy precipitation always occurs. On the other hand, there is an overall tendency of the simulations to favour cyclone development leeward of the Atlas mountain range and local rainfall enhancements over the exposed mountains of eastern Spain. The relative roles of the orography and sea surface latent-heat flux versus the action of the upper-level PV centres are examined by means of additional simulations. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Romero, R (reprint author), Univ Illes Balears, Dept Fis, E-07071 Palma de Mallorca, Spain. NR 46 TC 33 Z9 33 U1 1 U2 3 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD OCT PY 2001 VL 127 IS 578 BP 2559 EP 2597 DI 10.1256/smsqj.57804 PN B PG 39 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 500DX UT WOS:000172611600004 ER PT J AU Cundiff, ST Ye, J Hall, JL AF Cundiff, ST Ye, J Hall, JL TI Optical frequency synthesis based on mode-locked lasers SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Review ID TI-SAPPHIRE LASER; WAVE BRILLOUIN-SCATTERING; 1S-2S TRANSITION FREQUENCY; FINE-STRUCTURE CONSTANT; FEMTOSECOND-LASER; COMB GENERATION; PARAMETRIC OSCILLATOR; PHASE-CONTROL; LIGHT-PULSES; MU-M AB The synthesis of optical frequencies from the primary cesium microwave standard has traditionally been a difficult problem due to the large disparity in frequency. Recently this field has been dramatically advanced by the introduction and use of mode-locked lasers. This application of mode-locked lasers has been particularly aided by the ability to generate mode-locked spectra that span an octave. This review article describes how mode-locked lasers are used for optical frequency synthesis and gives recent results obtained using them. (C) 2001 American Institute of Physics. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Cundiff, ST (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. EM cundiffs@jila.colorado.edu RI Cundiff, Steven/B-4974-2009; Ye, Jun/C-3312-2011 OI Cundiff, Steven/0000-0002-7119-5197; NR 136 TC 153 Z9 155 U1 4 U2 37 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 2001 VL 72 IS 10 BP 3749 EP 3771 DI 10.1063/1.1400144 PG 23 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 475YL UT WOS:000171197600001 ER PT J AU Xiao, YK Swihart, GH Xiao, Y Vocke, RD AF Xiao, YK Swihart, GH Xiao, Y Vocke, RD TI A preliminary experimental study of the boron concentration in vapor and the isotopic fractionation of boron between seawater and vapor during evaporation of seawater SO SCIENCE IN CHINA SERIES B-CHEMISTRY LA English DT Article DE boron isotope; isotopic fractionation; evaporation; seawater ID IONIZATION MASS-SPECTROMETRY; ION-EXCHANGE SEPARATION; SEA-WATER; ATMOSPHERE AB A laboratory experiment was undertaken to investigate the behaviour of boron at the seawater-air interface under air flow conditions. Dried air at 25 and 35 degreesC was passed over or bubbled through seawater at the same temperature. A combination of ice-chilled condensers and KOH impregnated cellulose fibre filters was used to collect boron from the reacted air. When air stripped of boron was passed over the seawater, boron was found in the reacted air, and its concentration was higher in the higher temperature test. In the tests where air was bubbled through seawater the concentration of boron in the reacted air was directly proportional to the air flow rate. In this situation the boron in the reacted air was mainly introduced as a spray of microdroplets. Isotopic analysis of the collected boron in the non-bubbled tests yields fractionation factors which demonstrate that the lighter isotope, B-10, is enriched in the reacted air. The size of the fractionation changes with temperature, ruling out a purely kinetic effect. C1 Chinese Acad Sci, Qinghai Inst Salt Lakes, Xining 810008, Peoples R China. Univ Memphis, Dept Geol Sci, Memphis, TN 38152 USA. Natl Inst Stand & Technol, Inorgan Analyt Chem Div, Gaithersburg, MD 20899 USA. RP Xiao, YK (reprint author), Chinese Acad Sci, Qinghai Inst Salt Lakes, Xining 810008, Peoples R China. NR 18 TC 8 Z9 10 U1 2 U2 8 PU SCIENCE PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 1006-9291 J9 SCI CHINA SER B JI Sci. China Ser. B-Chem. PD OCT PY 2001 VL 44 IS 5 BP 540 EP 551 DI 10.1007/BF02880685 PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA 488ZL UT WOS:000171967200013 ER PT J AU Fenimore, C AF Fenimore, C TI Mastering and archiving uncompressed digital video test materials SO SMPTE JOURNAL LA English DT Article; Proceedings Paper CT 142nd SMPTE Technical Conference CY OCT 18-21, 2000 CL PASADENA, CALIFORNIA AB This is a report on the status of the SMPTE Ad Hoc Group (AHG) charged with creating a master set of standard-definition video sequences for subjective testing of electronic systems. The images will be available from SMPTE, for use in the evaluation of electronic systems. The first task is to create a master representation of video sequences enabling preservation in a consistent and stable storage environment. Once the sequences are restored and returned to a pristine state (when possible), they will be provided in digital file format to SMPTE. The Society will then offer the video sequences in various formats (digital data media and uncompressed digital videotape) for testing electronic systems. This report also includes representative images from sequences in a set of standard-definition materials, the first production of the AHG, Finally, feedback and suggestions on the quality and interest of this process is requested. C1 NIST, Digital Cinema Project, Gaithersburg, MD 20899 USA. RP Fenimore, C (reprint author), NIST, Digital Cinema Project, Gaithersburg, MD 20899 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU SOC MOTION PICTURE TV ENG INC PI WHITE PLAINS PA 595 WEST HARTSDALE AVE, WHITE PLAINS, NY 10607 USA SN 0036-1682 J9 SMPTE J JI SMPTE J. PD OCT PY 2001 VL 110 IS 10 BP 726 EP 735 PG 10 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Imaging Science & Photographic Technology; Telecommunications SC Engineering; Instruments & Instrumentation; Imaging Science & Photographic Technology; Telecommunications GA 484JN UT WOS:000171686600001 ER PT J AU Watanabe, M Haviland, DB Kautz, RL AF Watanabe, M Haviland, DB Kautz, RL TI Control of the electromagnetic environment for single Josephson junctions using arrays of dc SQUIDs SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID SMALL TUNNEL-JUNCTIONS; FABRICATION AB We have measured the current-voltage characteristics of small-capacitance single Josephson junctions at low temperatures (T less than or equal to 0.04 K), where the strength of the coupling between the single junction and the electromagnetic environment was controlled with one-dimensional arrays of dc SQUIDs. When the zero-bias resistance of the SQUID arrays is much higher than the quantum resistance h/e(2) approximate to 26 k Omega, a transition to a clear Coulomb blockade of Cooper-pair tunnelling is induced in the single junction. The measured blockade voltage agrees with the theoretical prediction. C1 Royal Inst Technol, KTH, SE-10044 Stockholm, Sweden. Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Watanabe, M (reprint author), RIKEN, Inst Phys & Chem Res, Semicond Lab, 2-1 Hirosawa, Wako, Saitama 3510198, Japan. NR 14 TC 3 Z9 3 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD OCT PY 2001 VL 14 IS 10 BP 870 EP 874 DI 10.1088/0953-2048/14/10/310 PG 5 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 488KD UT WOS:000171933600011 ER PT J AU Ravikiran, A Jahanmir, S AF Ravikiran, A Jahanmir, S TI Effect of contact pressure and load on wear of alumina SO WEAR LA English DT Article; Proceedings Paper CT 13th International Conference on Wear of Materials CY APR 22-26, 2001 CL VANCOUVER, CANADA DE alumina; wear; pressure ID MECHANISM; TRANSITION; CERAMICS; BEHAVIOR; MAPS AB Wear experiments were conducted in air using self-mated alumina in a pin-on-disk configuration at different loads using balls of different diameters as pins to maintain a constant value of initial Hertzian pressure. The selected initial load was kept constant for the rest of the sliding. Wear volume on the ball and the apparent contact pressures were calculated from the measured wear sear diameters on the balls at regular sliding intervals. The results show reduction in wear coefficient with sliding distance, as the contact pressure reduces (due to increment in the contact area). However, a good correlation was observed between the normalized wear rate and the apparent contact pressure, irrespective of the applied load, sliding distance, ball diameter and apparent contact area. This observation is explained based on the assumption that besides the asperities that deform plastically a large portion of the asperities deforms elastically and carries the applied load. It is argued that for a mixed elastic/plastic contact the number of plastically loaded asperities, and therefore, the wear rate, should depend on the apparent contact pressure. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Ravikiran, A (reprint author), Natl Inst Stand & Technol, Mfg Syst Integrat Div, Gaithersburg, MD 20899 USA. EM aravi@nist.gov NR 19 TC 29 Z9 30 U1 1 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD OCT PY 2001 VL 251 BP 980 EP 984 DI 10.1016/S0043-1648(01)00739-6 PN 2 PG 5 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 489VJ UT WOS:000172012900019 ER PT J AU Bu, ZM Cook, J Callaway, DJE AF Bu, ZM Cook, J Callaway, DJE TI Dynamic regimes and correlated structural dynamics in native and denatured alpha-lactalbumin SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE protein folding; protein folding dynamics; diffusion; neutron scattering; molten globule ID PROTEIN-FOLDING DYNAMICS; MOLTEN GLOBULE; STAPHYLOCOCCAL NUCLEASE; GUINEA-PIG; STATE; SCATTERING; MECHANISM; MODEL; LANDSCAPE; TOPOLOGY AB Understanding the mechanisms of protein folding requires knowledge of both the energy landscape and the structural dynamics of a protein. We report a neutron-scattering study of the nanosecond and picosecond dynamics of native and the denatured a-lactalbumin. The quasielastic scattering intensity shows that there are alpha -helical structure and tertiary-like side-chain interactions fluctuating on sub-nanosecond time-scales under extremely denaturing conditions and even in the absence of disulfide bonds. Based on the length-scale dependence of the decay rate of the measured correlation functions, the nanosecond dynamics of the native and the variously denatured proteins have three dynamic regimes. When 0.05 < Q < 0.5 Angstrom (-1) (where the scattering vector, Q, is inversely proportional to the length-scale), the decay rate, F, shows a power law relationship, Gamma proportional to Q(2.42 +/- 0.08), that is analogous to the dynamic behavior of a random coil. However, when 0.5 < Q <1.0 Angstrom (-1), the decay rate exhibits a Gamma proportional to Q(1.0 +/- 0.2) relationship. The effective diffusion constant of the protein decreases with increasing Q, a striking dynamic behavior that is not found in any chain-like macromolecule. We suggest that this unusual dynamics is due to the presence of a strongly attractive force and collective conformational fluctuations in both the native and the denatured states of the protein. Above Q > 1.0 Angstrom (-1) is a regime that displays the local dynamic behavior of individual residues, Gamma proportional to Q(1.8 +/- 0.3). The picosecond time-scale dynamics shows that the potential barrier to side-chain proton jump motion is reduced in the molten globule and in the denatured proteins when compared to that of the native protein. Our results provide a dynamic view of the native-like topology established in the early stages of protein folding. (C) 2001 Academic Press. C1 NIST, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. Picower Inst Med Res, Manhasset, NY 11030 USA. RP Bu, ZM (reprint author), NIST, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. EM zimei.bu@nist.gov NR 44 TC 32 Z9 33 U1 0 U2 7 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD SEP 28 PY 2001 VL 312 IS 4 BP 865 EP 873 DI 10.1006/jmbi.2001.5006 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 481TP UT WOS:000171536600024 PM 11575938 ER PT J AU Mahrt, L Vickers, D Sun, JL Crawford, TL Crescenti, G Frederickson, P AF Mahrt, L Vickers, D Sun, JL Crawford, TL Crescenti, G Frederickson, P TI Surface stress in offshore flow and quasi-frictional decoupling SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MARINE BOUNDARY-LAYER; DRAG COEFFICIENTS; MOMENTUM-TRANSFER; OCEAN SURFACE; COASTAL ZONE; WIND-SPEED; SEA; ROUGHNESS; EVOLUTION; VECTOR AB Aircraft data collected at approximately 15 m above the sea surface in the coastal zone are analyzed to examine the spatial distribution of surface stress. Advection of stronger turbulence from land dominates the near-surface turbulence for the first few kilometers offshore. With offshore flow of warm air over cold water, strong stratification leads to very small surface stress. Because the stability restricts the momentum transfer to the waves, the aerodynamic surface roughness decreases to very small values, which in turn decreases atmospheric mixing. The redevelopment of the boundary layer farther downstream is examined. Computation of fluxes from observations for stable cases is difficult due to a variety of errors including large random flux errors, possible instrumental loss of small-scale flux, difference between the surface flux and that at the observational level, and inadvertent capture of mesoscale motions in the computed turbulent fluctuations. Although the errors appear to be substantial, the aircraft momentum fluxes compare favorably with those from sonic anemometers on two buoys and a tower at the end of a 570-m pier, even with near collapse of the turbulence. C1 Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. NOAA, Air Resources Lab, Idaho Falls, ID 83402 USA. USN, Postgrad Sch, Monterey, CA 93943 USA. Natl Ctr Atmospher Res, Boulder, CO USA. RP Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. EM mahrt@oce.orst.edu RI Sun, Jielun/H-6576-2015 OI Sun, Jielun/0000-0003-3271-7914 NR 36 TC 16 Z9 16 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 2001 VL 106 IS D18 BP 20629 EP 20639 DI 10.1029/2000JD000159 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 476FV UT WOS:000171216300001 ER PT J AU Sheridan, PJ Delene, DJ Ogren, JA AF Sheridan, PJ Delene, DJ Ogren, JA TI Four years of continuous surface aerosol measurements from the Department of Energy's Atmospheric Radiation Measurement Program Southern Great Plains Cloud and Radiation Testbed site SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTHROPOGENIC AEROSOLS; NEPHELOMETER; SULFATE; SMOKE AB Continuous measurements of the optical and microphysical properties of aerosol particles have been made at the Department of Energy's Atmospheric Radiation Measurement Program Southern Great Plains Cloud and Radiation Testbed (CART) site covering the 4-year period from July 1996 through June 2000. Hourly, daily, and monthly statistics have been calculated that illustrate aerosol variability over a range of timescales. A pronounced peak in total particle number, centered on the midafternoon hours (local time), is evident in the hourly statistics. A broad early morning peak in the concentration of particles >0.1-mum aerodynamic diameter corresponds with a similar peak in aerosol light-scattering coefficient, sigma (sp). No strong cycles were observed in the daily statistics, suggesting that day of the week has only a minor influence on the observed aerosol variability. The a, at a wavelength of 550 nm for the 4-year period showed a median value of 33 Mm(-1) and was highest in February and August. The median fraction of aerosol light scattering at 550 nm due to particles <1-mum aerodynamic diameter was 0.85 over the entire record. The median aerosol light absorption coefficient, sigma (ap) for the 4-year period was similar to1.5 Mm(-1) and was observed to be highest in late summer and autumn. The sigma (ap) showed an increasing trend of nearly 0.5 Mm(-1) yr, possibly due to increased agricultural field burning in the area. The occurrence of an autumn decrease in single-scattering albedo, omega (0), was observed and may be caused by regional-scale agricultural or transportation activities or seasonal changes in atmospheric flow patterns. The median value for omega (0) over the 4-year period was 0.95, but this value has decreased similar to1-2% yr(-1) presumably due to increased agricultural burning. Numerous field fires during the second half of 1999 influenced the surface aerosol at the CART site causing substantial variability of aerosol optical properties. The aerosol hygroscopic growth factor (f(RH)), corresponding to a relative humidity increase of 40-85%, showed a median value of 1.83 for 1999, although much lower values were observed during periods that were probably influenced by locally generated smoke and dust aerosols (median f(RH) = 1.55 and 1.59, respectively). C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Sheridan, PJ (reprint author), NOAA, Climate Monitoring & Diagnost Lab, 325 Broadway, Boulder, CO 80303 USA. EM patrick.sheridan@noaa.gov; jogren@cmdl.noaa.gov RI Ogren, John/M-8255-2015 OI Ogren, John/0000-0002-7895-9583 NR 22 TC 124 Z9 127 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 2001 VL 106 IS D18 BP 20735 EP 20747 DI 10.1029/2001JD000785 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 476FV UT WOS:000171216300009 ER PT J AU Bates, TS Quinn, PK Coffman, DJ Johnson, JE Miller, TL Covert, DS Wiedensohler, A Leinert, S Nowak, A Neususs, C AF Bates, TS Quinn, PK Coffman, DJ Johnson, JE Miller, TL Covert, DS Wiedensohler, A Leinert, S Nowak, A Neususs, C TI Regional physical and chemical properties of the marine boundary layer aerosol across the Atlantic during Aerosols99: An overview SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SEA-SALT SULFATE; EXPERIMENT ACE 1; BIOGENIC SULFUR EMISSIONS; CLOUD CONDENSATION NUCLEI; TROPICAL SOUTH-ATLANTIC; LONG-RANGE TRANSPORT; SIZE DISTRIBUTION; TROPOSPHERIC AEROSOLS; SEASONAL-VARIATIONS; NORTH-ATLANTIC AB The Aerosols99 cruise crossed the Atlantic Ocean from Norfolk, Virginia, to Cape Town, South Africa, between January 14 and February 8, 1999. The goals of the cruise were to determine the chemical, physical, and optical properties of the marine boundary layer (MBL) aerosol, the vertical distribution of aerosols and ozone, the column-integrated aerosol optical depth, and the ozone, CO, and peroxy radical chemistry in the MBL. Sampling strategies were optimized to obtain data sets to evaluate satellite-derived ocean color (Sea-viewing Wide Field-of-view Sensor), aerosol optical depth (advanced very high resolution radiometer) and total column ozone (Total Ozone Mapping Spectrometer). The cruise track crossed through seven different meteorological/oceanographic regimes ranging from background marine air masses in the Northern and Southern Hemispheres to air masses containing mineral dust and the products of biomass burning. This overview discusses the seven regimes encountered enroute and the chemical and physical properties of the MBL aerosol in each regime. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98195 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Inst Tropospher Res, D-04318 Leipzig, Germany. RP Bates, TS (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. EM bates@pmel.noaa.gov RI Nowak, Andreas/B-6413-2014; Bates, Timothy/L-6080-2016; Quinn, Patricia/R-1493-2016 OI Quinn, Patricia/0000-0003-0337-4895 NR 58 TC 56 Z9 57 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 2001 VL 106 IS D18 BP 20767 EP 20782 DI 10.1029/2000JD900578 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 476FV UT WOS:000171216300012 ER PT J AU Quinn, PK Coffman, DJ Bates, TS Miller, TL Johnson, JE Voss, K Welton, EJ Neususs, C AF Quinn, PK Coffman, DJ Bates, TS Miller, TL Johnson, JE Voss, K Welton, EJ Neususs, C TI Dominant aerosol chemical components and their contribution to extinction during the Aerosols99 cruise across the Atlantic SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MARINE BOUNDARY-LAYER; EXPERIMENT ACE 1; GLOBAL 3-DIMENSIONAL MODEL; LIGHT-SCATTERING; OPTICAL DEPTH; ATMOSPHERIC AEROSOLS; RADIATIVE PROPERTIES; STRONG ELECTROLYTES; PARTICULATE MATTER; AQUEOUS-SOLUTIONS AB The Aerosols99 cruise crossed the Atlantic Ocean from Norfolk, Virginia, to Cape Town, South Africa, during January and February of 1999. On the basis of back trajectories, aerosol number concentrations and size distributions, and trace gas concentrations, seven "air mass" regions were encountered. These included North America, Northern Hemisphere (NH) marine, African dust, a mixture of dust and biomass burning from Africa, biomass burning from Africa, Southern Hemisphere SH) marine tropics, and SH marine temperate. Simultaneous measurements of aerosol chemical composition, number size distribution, scattering and absorption coefficients, vertical profiles, and optical depth allowed for a thorough characterization of the aerosol. Presented here are the concentrations and mass fractions of the aerosol chemical components that were dominant in each region and the aerosol scattering and absorption coefficients, single scattering albedos, Angstrom ngstrom exponents, and optical depths measured in each region. Also presented is the percent of the extinction measured at the surface due to each chemical component and mass extinction efficiencies of the individual aerosol components estimated from Mie calculations and a multiple linear regression. All results are reported at the measurement relative humidity of 55 +/- 5%. Non-sea-salt (nss) SO aerosol was a significant contributor to the submicron mass concentration in all air mass regions (mean mass fractions ranged from 20 to 67%). It made the largest contribution to submicron extinction in the North America region (45 +/- 30%, mean and 1 sigma standard deviation). Sea-salt mean submicron mass fractions ranged from 9 to 49% with the lowest value in the biomass burning region and highest values in the NH marine and dust regions. Its contribution to submicron extinction ranged from a mean of 29 to 66%. Sea-salt mean supermicron mass fractions ranged from 52 to 98% with the highest values in the marine regions. Its contribution to supermicron extinction ranged from 60 to 98%. Mean submicron and supermicron mass fractions of dust in the dust region were 22 +/- 3.3% (mean and 95% uncertainty) and 26 +/- 3.9%, respectively. Corresponding submicron and supermicron extinction contributions were 24 +/- 7.5 and 18 +/- 4.0%, respectively. Submicron mass fractions of particulate organic matter (POM) ranged from below detection limits in the dust region to 18 +/- 11% in the biomass burning region. Contributions to submicron extinction ranged from below detection limits to 24% in the North America region. In the biomass burning region the black carbon mean submicron mass fraction was 6.7 +/- 1.3% with a contribution of 6.4 +/- 2.7% to the submicron extinction. Extinction fractions of each component for particles with aerodynamic diameters less than 10 mum also are reported in the paper. Sea salt dominated the extinction measured at the surface due to sub-10 mum aerosol for all air mass regions, even those influenced by continental sources. The fraction of the measured column aerosol optical depth due to aerosol within the 'boundary layer was estimated for the NH marine, dust, biomass burning, and SH marine tropics regions. Mean values ranged from 35 +/- 15% for the biomass burning region to 95 +/- 46% for the NH marine region. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. Univ Miami, Dept Phys, Miami, FL 33149 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. Inst Tropospher Res, D-04318 Leipzig, Germany. RP Quinn, PK (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. EM quinn@pmel.noaa.gov RI Welton, Ellsworth/A-8362-2012; Voss, Kenneth /A-5328-2013; Bates, Timothy/L-6080-2016; Quinn, Patricia/R-1493-2016 OI Voss, Kenneth /0000-0002-7860-5080; Quinn, Patricia/0000-0003-0337-4895 NR 61 TC 60 Z9 62 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 2001 VL 106 IS D18 BP 20783 EP 20809 DI 10.1029/2000JD900577 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 476FV UT WOS:000171216300013 ER PT J AU Voss, KJ Welton, EJ Quinn, PK Frouin, R Miller, M Reynolds, RM AF Voss, KJ Welton, EJ Quinn, PK Frouin, R Miller, M Reynolds, RM TI Aerosol optical depth measurements during the Aerosols99 experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SHIPBOARD; TABLES; INDEX; OZONE; AIR AB The Aerosols99 cruise took place during the period from January 14 to February 8, 1999, on the R/V Ronald Brown. The cruise track was almost a straight line in the southeast direction from Norfolk, Virginia, to Cape Town, South Africa, and afforded the opportunity to sample several different aerosol regimes over the North and South Atlantic. Handheld sunphotometers, a shadowband radiometer (FRSR), and a LIDAR were used to measure the aerosol optical depth (AOD) during the cruise. The AOD and angstrom exponent a (spectral dependence of the AOD) varied strongly between regimes. Maritime regions typically had AOD (500 nm) of approximately 0.10 +/- 0.03, with a around 0.3 +/- 0.3. An African dust event was encountered in which the AOD (500 nm) averaged 0.29 +/- 0.05 with an alpha of 0.36 +/- 0.13. At the Intertropical Convergence Zone (ITCZ), no measurements were obtained because of cloudiness; however, after the ITCZ we encountered a biomass burning aerosol with high average AOD (500 nm) of 0.36 +/- 0.13, and a high alpha (0.88 +/- 0.30). Farther south the aerosol went back to the low levels of a typical marine aerosol. C1 Univ Miami, Dept Phys, Miami, FL 33146 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. Univ Calif San Diego, Inst Oceanog Sci, La Jolla, CA 92037 USA. Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. RP Voss, KJ (reprint author), Univ Miami, Dept Phys, Miami, FL 33146 USA. EM voss@physics.miami.edu RI Welton, Ellsworth/A-8362-2012; Voss, Kenneth /A-5328-2013; Quinn, Patricia/R-1493-2016 OI Voss, Kenneth /0000-0002-7860-5080; Quinn, Patricia/0000-0003-0337-4895 NR 16 TC 20 Z9 21 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 2001 VL 106 IS D18 BP 20811 EP 20819 DI 10.1029/2000JD900783 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 476FV UT WOS:000171216300014 ER PT J AU Voss, KJ Welton, EJ Quinn, PK Johnson, J Thompson, AM Gordon, HR AF Voss, KJ Welton, EJ Quinn, PK Johnson, J Thompson, AM Gordon, HR TI Lidar measurements during Aerosols99 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TO-BACKSCATTER RATIO; LIGHT-SCATTERING; OPTICAL-PROPERTIES; OCEAN COLOR AB The Aerosols99 cruise (January 14 to February 8, 1999) went between Norfolk, Virginia, and Cape Town, South Africa. A Micropulse lidar system was used almost continually during this cruise to profile the aerosol vertical structure. Inversions of this data illustrated a varying vertical structure depending on the dominant air mass. In clean maritime aerosols in the Northern and Southern Hemispheres the aerosols were capped at 1 km. When a dust event from Africa was encountered, the aerosol extinction increased its maximum height to above 2 km. During a period in which the air mass was dominated by biomass burning from southern Africa, the aerosol layer extended to 4 km. Comparisons of the aerosol optical depth (AOD) derived from lidar inversion and surface Sun photometers showed an agreement within +/-0.05 RMS. Similar comparisons between the extinction measured with a nephelometer and particle soot absorption photometer (at 19 m altitude) and the lowest lidar measurement (75 m) showed good agreement (+/-0.014 km(-1)). The lidar underestimated surface extinction during periods when an elevated aerosol layer (total AOD > 0.10) was present over a relatively clean (aerosol extinction < 0.05 km(-1)) surface layer, but otherwise gave accurate results. C1 Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. RP Voss, KJ (reprint author), Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. EM voss@physics.miami.edu RI Welton, Ellsworth/A-8362-2012; Voss, Kenneth /A-5328-2013; Quinn, Patricia/R-1493-2016; Thompson, Anne /C-3649-2014 OI Voss, Kenneth /0000-0002-7860-5080; Quinn, Patricia/0000-0003-0337-4895; Thompson, Anne /0000-0002-7829-0920 NR 22 TC 40 Z9 45 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 SEP 27 PY 2001 VL 106 IS D18 BP 20821 EP 20831 DI 10.1029/2001JD900217 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 476FV UT WOS:000171216300015 ER PT J AU Zhang, YM Ge, S Tang, B Koga, T Rafailovich, MH Sokolov, JC Peiffer, DG Li, Z Dias, AJ McElrath, KO Lin, MY Satija, SK Urquhart, SG Ade, H Nguyen, D AF Zhang, YM Ge, S Tang, B Koga, T Rafailovich, MH Sokolov, JC Peiffer, DG Li, Z Dias, AJ McElrath, KO Lin, MY Satija, SK Urquhart, SG Ade, H Nguyen, D TI Effect of carbon black and silica fillers in elastomer blends SO MACROMOLECULES LA English DT Article ID POLYMER MOBILITY; REFLECTIVITY; INTERFACE; DIFFUSION; RUBBER; FILMS AB The effects of carbon black and pyrogeneous silica fillers on the interfacial properties of a homopolymer [polybutadiene, (PB)] and a terpolymer [brominated poly(isobutylene-co-p-metliylstyrene), (BIMS)] are reported. Neutron reflectivity (NR) was used to study the interfacial structure. The results are complemented by scanning transmission X-ray microscopy (STXM) and lateral force microscopy (LFM), which were used to probe the morphology and surface lateral force. Small-angle neutron scattering (SANS) was used to characterize the size and surface properties of the filler aggregates in elastomers. Our results show that the interfacial behavior of PB/BIMS is more sensitive to carbon black than to silica. The interfacial broadening is significantly slowed down with addition of merely phi (CB) = 0.01 (volume fraction) carbon black fillers. This volume level is much lower than that used in bulk rubbers (phi (CB) greater than or equal to 0.1). Pyrogeneous silica has a less pronounced effect on the interfacial characteristics. When both carbon and silica are incorporated into the PB layer, the effect of carbon black is offset by silica fillers. C1 SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Exxon Res & Engn Co, Annandale, NJ 08801 USA. Exxon Chem Co, Polymer Sci Div, Baytown, TX 77520 USA. Exxon Chem Co, Butyl Technol Div, Baytown, TX 77520 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Rafailovich, MH (reprint author), SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. RI Koga, Tadanori/A-4007-2010; Ade, Harald/E-7471-2011; Urquhart, Stephen/A-6237-2014 OI Urquhart, Stephen/0000-0002-6415-6341 NR 32 TC 32 Z9 35 U1 1 U2 28 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 25 PY 2001 VL 34 IS 20 BP 7056 EP 7065 DI 10.1021/ma010183p PG 10 WC Polymer Science SC Polymer Science GA 475ZD UT WOS:000171199300029 ER PT J AU Liu, CY Lee, S Chuang, TJ AF Liu, CY Lee, S Chuang, TJ TI Grain boundary crack growth in interconnects with an electric current SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article DE grain boundary; crack growth; interconnect; electromigration ID ELECTROMIGRATION DAMAGE; TRANSGRANULAR SLITS; ACTIVATION-ENERGY; GOLD-FILMS; VOIDS; LINES; MECHANISMS; INTERFACES; DEPENDENCE; FAILURE AB Failure of thin-film interconnects poses a great concern in semiconductor devices. Due to the high electric current density in interconnects, electromigration-induced atomic flux is recognized as an important failure mechanism. For wide polycrystalline interconnects, atomic flux along grain boundaries is believed to be the major failure mechanism. In situ transmission electron microscopy observations revealed void propagation along grain boundaries. Thus, we consider steady state crack growth along a grain boundary in an interconnect subjected to a high current density. Crack growth occurs via mass transport driven by surface curvature and electric field. For crack propagation transverse to the remote electric field, the direction of electric field on one crack surface is opposite to that on the other crack surface. The governing equation is derived and a numerical solution presented. The results indicated that crack growth rate and width are proportional to /E-0/(3/2) and /E-0/(-1/2), respectively, where E-0 is the applied electric field. The crack tip morphology map can be divided into four regions for all materials with a known ratio of boundary to surface free energies: Case I is defined as that both crack tip angles are positive, Case II, one of crack angles is 0 degrees, and Case III, one crack tip angle is positive and the other is negative, Case IV corresponds to that crack growth is physically impossible to occur. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Tsing Hua Univ, Dept Mat Sci & Engn, Hsinchu 30043, Taiwan. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Natl Tsing Hua Univ, Dept Mat Sci & Engn, Hsinchu 30043, Taiwan. NR 36 TC 6 Z9 6 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD SEP 25 PY 2001 VL 86 IS 2 BP 101 EP 108 DI 10.1016/S0921-5107(00)00804-7 PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 465HR UT WOS:000170584000001 ER PT J AU Curry, JJ Adler, HG Shastri, SD Lawler, JE AF Curry, JJ Adler, HG Shastri, SD Lawler, JE TI Minority additive distributions in a ceramic metal-halide arc lamp using high-energy x-ray induced fluorescence SO APPLIED PHYSICS LETTERS LA English DT Article ID DISCHARGE; DENSITY AB X-ray induced fluorescence is used to measure the elemental densities of minority additives in a metal-halide arc contained inside a translucent ceramic envelope. A monochromatic x-ray beam from the Sector 1 Insertion Device beamline at the Advanced Photon Source is used to excite K-shell x-ray fluorescence in the constituents of a ceramic metal-halide arc lamp dosed with DyI3 and CsI. Fluorescence and scattered photons are collected by a cryogenic energy-resolving Ge detector. The high signal-to-noise spectra show strong fluorescence from Dy, Cs, and I, as well as elastic scattering from Hg. Radial distributions of the absolute elemental densities of Dy, Cs, and I are obtained. (C) 2001 American Institute of Physics. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. OSRAM Sylvania, Beverly, MA 01915 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Curry, JJ (reprint author), Natl Inst Stand & Technol, Stop 8421, Gaithersburg, MD 20899 USA. NR 13 TC 17 Z9 17 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 24 PY 2001 VL 79 IS 13 BP 1974 EP 1976 DI 10.1063/1.1404401 PG 3 WC Physics, Applied SC Physics GA 472ZQ UT WOS:000171015200015 ER PT J AU Baker, ET Cormier, MH Langmuir, CH Zavala, K AF Baker, ET Cormier, MH Langmuir, CH Zavala, K TI Hydrothermal plumes along segments of contrasting magmatic influence, 15 degrees 20 '-18 degrees 30 ' N, East Pacific Rise: Influence of axial faulting SO GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS LA English DT Article DE East Pacific Rise; hydrothermal plumes; tectonics; magmatic budget; marine geology and geophysics; midocean ridge processes; hydrothermal systems ID MID-ATLANTIC RIDGE; MIDOCEAN RIDGES; SPREADING CENTERS; FUCA RIDGE; SYSTEM; JUAN; CONSTRAINTS; BUDGET; OCEAN; WATER AB [1] Vertical profiles of light backscattering and temperature recorded on 133 rock cores and dredge hauls between the Orozco and Rivera transform faults on the East Pacific Rise (EPR) (15 degrees 20'- 18 degrees 30'N) provide an opportunity to compare the hydrothermal environment of three adjacent but distinctly different segments that span the maximum range of axial cross section at a relatively constant spreading rate. Contrary to predictions based on data from other Pacific ridges, hydrothermal plumes over the inflated 16 degrees N segment were less extensive and weaker than along the narrower, rifted 17 degrees N segment. Remarkably, the 17 degrees N segment has a plume incidence equal to the mean of superfast spreading segments from the southern EPR. The data suggest that the local permeability environment in this region controls the expression of hydrothermal activity in the water column. The 16 degrees N segment, which has little or no indication of faulting, may have its hydrothermal activity presently suppressed by widespread volcanic flows that act as an impermeable cap over much of the segment. Activity on the 17 degrees N segment may be tectonically enhanced, with hydrothermal fluids circulating through deep faults to a cracking front. Within each segment, intense hydrothermal plumes characteristic of focused discharge seem associated with clearly rifted areas, while weaker water column signals characteristic of diffuse discharge are associated with unrifted portions of the ridge axis that appear dominated by magmatism. Previous studies at intermediate- to-superfast spreading ridges have emphasized a positive correlation between local magmatic budget and hydrothermal activity. Our data suggest, however, that even at fast rates local tectonics can control the extent and nature of hydrothermal activity, as documented for several sites on the slow-spreading Mid-Atlantic Ridge. Despite the segment-scale incongruity between hydrothermal activity and magmatic budget, the fraction of total ridge length between 15 degrees 20' and 18 degrees 30'N overlain by plumes (0.39) follows the existing global correlation between plume incidence and spreading rate. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Lamont Doherty Earth Observ, Palisades, NY 10964 USA. RP Baker, ET (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 34 TC 9 Z9 9 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1525-2027 J9 GEOCHEM GEOPHY GEOSY JI Geochem. Geophys. Geosyst. PD SEP 24 PY 2001 VL 2 AR 2000GC000165 DI 10.1029/2000GC000165 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 474YK UT WOS:000171134500001 ER PT J AU Kriesel, JM Driscoll, CF AF Kriesel, JM Driscoll, CF TI Measurements of viscosity in pure-electron plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID NONNEUTRAL PLASMAS; THERMAL-EQUILIBRIUM; PARTICLE-TRANSPORT; DYNAMICS; CRYSTALS; VORTEX AB Measurements of the viscosity in quiescent magnetized pure-electron plasmas are up to 10(8) times larger than predicted by classical collisional theory. This strong viscosity is due to long-range "E x B drift collisions" between electrons separated by up to a Debye length. Recent theories of long-range collisions show order-of-magnitude agreement with the measurements, but do not give the observed dependence on the plasma column length. A simple empirical scaling law fits the length and magnetic field dependence surprisingly well. C1 Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Kriesel, JM (reprint author), NIST, Div Time & Frequency, 325 Broadway, Boulder, CO 80305 USA. NR 27 TC 17 Z9 17 U1 0 U2 2 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 SEP 24 PY 2001 VL 87 IS 13 AR 135003 DI 10.1103/PhysRevLett.87.135003 PG 4 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500028 PM 11580598 ER PT J AU Steinbach, A Joyez, P Cottet, A Esteve, D Devoret, MH Huber, ME Martinis, JM AF Steinbach, A Joyez, P Cottet, A Esteve, D Devoret, MH Huber, ME Martinis, JM TI Direct measurement of the Josephson supercurrent in an ultrasmall Josephson junction SO PHYSICAL REVIEW LETTERS LA English DT Article ID SINGLE-ELECTRON TRANSISTOR; TUNNEL-JUNCTIONS; PHASE DIFFUSION; COMPUTATION AB We have measured the supercurrent flowing through a nonhysteretic, ultrasmall, volta-c-biased Joseph son junction. In contrast with experiments performed so far on hysteretic Josephson junctions, we find a supercurrent peak whose maximum I-s max increases as the temperature T decreases. The asymptotic T = 0 value of I-s max agrees with the junction Arnbegaokar-Baratoff critical current, as predicted by theory. C1 CEA Saclay, Serv Phys Etat Condense, F-91191 Gif Sur Yvette, France. Univ Colorado, Dept Phys, Denver, CO 80217 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Steinbach, A (reprint author), CEA Saclay, Serv Phys Etat Condense, F-91191 Gif Sur Yvette, France. RI Huber, Martin/B-3354-2011; Cottet, Audrey/F-7769-2011 OI Cottet, Audrey/0000-0003-2044-7718 NR 32 TC 52 Z9 52 U1 0 U2 2 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 SEP 24 PY 2001 VL 87 IS 13 AR 137003 DI 10.1103/PhysRevLett.87.137003 PG 4 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500048 PM 11580618 ER PT J AU Halonen, L Bernasek, SL Nesbitt, DJ AF Halonen, L Bernasek, SL Nesbitt, DJ TI Reactivity of vibrationally excited methane on nickel surfaces SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ACTIVATED DISSOCIATIVE CHEMISORPTION; POTENTIAL-ENERGY SURFACES; LOCAL MODE VIBRATIONS; MOLECULAR-BEAM; VARIATIONAL CALCULATIONS; TETRAHEDRAL MOLECULES; CH4 DISSOCIATION; PRESSURE GAP; NI(111); SCATTERING AB Four-dimensional variational calculations have been performed for modeling energy flow between methane (CH4) stretching vibrational energy states as the molecule adiabatically approaches a metallic surface. The model is based on a local mode Hamiltonian for an isolated CH4 molecule and a London-Eyring-Polanyi-Sato potential describing surface-molecule interactions. The results suggest the possibility of mode specific effects on chemical reactivity. Specifically, the symmetric A(1) stretch fundamental adiabatically correlates with the localized excitation in the unique CH bond pointing towards the surface. Conversely, the antisymmetric F-2 stretch fundamental excitation correlates with A and E vibrations in the CH3 radical, and therefore this degree of freedom is localized away from the reactive CH bond. Landau-Zener semiclassical analysis of nonadiabatic curve crossings predicts a significant velocity dependence to the state specific energy flow dynamics. Since excitation localized in active versus spectator bonds is expected to be more efficient in accelerating CH bond cleavage and adsorption reactivity, these results offer insight into interpreting velocity and vibrationally mediated reaction dynamics of CH4 on catalytic surfaces. (C) 2001 American Institute of Physics. C1 Univ Helsinki, Chem Phys Lab, FIN-00014 Helsinki, Finland. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Halonen, L (reprint author), Univ Helsinki, Chem Phys Lab, POB 55,AI Virtasen Aukio 1, FIN-00014 Helsinki, Finland. NR 47 TC 65 Z9 65 U1 0 U2 10 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 22 PY 2001 VL 115 IS 12 BP 5611 EP 5619 DI 10.1063/1.1398075 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 472YZ UT WOS:000171013700034 ER PT J AU Zimmerman, MH Baskin, DM Faber, KT Fuller, ER Allen, AJ Keane, DT AF Zimmerman, MH Baskin, DM Faber, KT Fuller, ER Allen, AJ Keane, DT TI Fracture of a textured anisotropic ceramic SO ACTA MATERIALIA LA English DT Article DE ceramics; fracture & fracture toughness; small angle neutron scattering; texture ID THERMAL-EXPANSION ANISOTROPY; POLE FIGURES; MICROSTRUCTURES; STABILITY; CRACKING; TITANATE AB The role of crystallographic texture in determining the fracture behavior of a highly anisotropic ceramic, iron titanate, has been examined. By exploiting the anisotropy in its single crystal magnetic susceptibility, crystallographically textured and untextured iron titanate microstructures were formed by gelcasting in the presence and absence of a strong magnetic field, respectively. The magnetic field-assisted processing imparted a fiber-like texture to the processed ceramic material in which the crystallographic b-axes of the grains aligned parallel to the applied field. Triaxial residual stress and lattice parameter measurements showed that both the untextured and textured materials had undergone significant stress-relaxation, presumably due to spontaneous microcracking. Further, 'aggregates' of non-textured material were discovered within textured material that led to a population of meso-scale cracks (meso-cracks) in the microstructure oriented normal to the direction of alignment. Both crack populations were examined using a finite element simulation and confirmed by small angle neutron scattering measurements, and for meso-cracks, by X-ray tomography. Bend strength and R-curve behavior were evaluated as a function of texture and orientation in the magnetically processed materials. Strengths remained within 20% of that of the control material, except for one orientation, for which the strength decreased with increasing degree of texture due to favorably oriented meso-cracks. The R-curve behavior was highly anisotropic, with the peak fracture toughness of the magnetically processed material ranging from approximately equal to 2.5 times that of the control material. Additionally, the peak fracture toughness of each orientation increased with the degree Of texture. Anisotropic fracture properties were related to interactions between the test crack and the population of meso-cracks. (C) 2001 Acta Materialia Inc, Published by Elsevier Science Ltd. All rights reserved. C1 Northwestern Univ, Dept Mat Sci & Engn, Robert R McCormick Sch Engn & Appl Sci, Evanston, IL 60208 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Faber, KT (reprint author), Northwestern Univ, Dept Mat Sci & Engn, Robert R McCormick Sch Engn & Appl Sci, Evanston, IL 60208 USA. RI Faber, Katherine/B-6741-2009 NR 43 TC 24 Z9 26 U1 1 U2 10 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 SEP 20 PY 2001 VL 49 IS 16 BP 3231 EP 3242 DI 10.1016/S1359-6454(01)00224-5 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 476VG UT WOS:000171249000010 ER PT J AU Elvidge, CD Hobson, VR Baugh, KE Dietz, JB Shimabukuro, YE Krug, T Novo, EMLM Echavarria, FR AF Elvidge, CD Hobson, VR Baugh, KE Dietz, JB Shimabukuro, YE Krug, T Novo, EMLM Echavarria, FR TI DMSP-OLS estimation of tropical forest area impacted by surface fires in Roraima, Brazil: 1995 versus 1998 SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID AMAZON; DEFORESTATION; IMAGES AB A procedure has been developed to locate and estimate the area of heavy forest burning based on the frequency of DMSP-OLS (US Air Force Defense Meteorological Satellite Program Operational Linescan System) fire detection from time series of observations across the fire season. A calibration was developed for Roraima, Brazil, using Landsat Thematic Mapper (TM) data acquired near the end of the 1998 burn season and analysed to identify unburnt, partially burnt and heavily burnt forest areas. A fire detection frequency threshold of five nights was used to map heavily burnt forest using the 3 months of DMSP-OLS observations. The threshold of five fire detections, which could occur anytime during the 3-month time period, was selected to constrain errors of commission involving unburnt forest to 10% of the total area for unburnt forest in the calibration area. At this threshold setting the DMSP-OLS estimate of heavily burnt forest area covered 79% of the Landsat measured area. It was found that 77% of the 1998 heavily burnt forest area was outside of the state's protected areas (national parks, reserves, indigenous areas). Two of the protected areas sustained a substantial increase in heavily burnt forest in 1998 relative to 1995 (Reserva Biologica Mucajai and Parque Indigena Yanomami). The 1998 forest burning in these two areas was concentrated in their eastern-most sections. The core of the Yanomami area did not sustain extensive burning in 1998. Protected areas in the north-eastern section of the state, where forests are mixed with cerrado, had moderate increases in heavily burnt forest in 1998. Other protected areas were largely free of the heavy forest burning, which was concentrated to the west of the state's primary cerrado zone. C1 NOAA, Natl Geophys Data Ctr, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80303 USA. Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. Inst Nacl Pesquisas Espaciais, Sao Paulo, Brazil. US Dept State, Off Ecol, Washington, DC 20520 USA. RP Elvidge, CD (reprint author), NOAA, Natl Geophys Data Ctr, 325 Broadway, Boulder, CO 80303 USA. RI Elvidge, Christopher/C-3012-2009 NR 16 TC 25 Z9 28 U1 0 U2 12 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD SEP 20 PY 2001 VL 22 IS 14 BP 2661 EP 2673 DI 10.1080/01431160120888 PG 13 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 473DC UT WOS:000171023800001 ER PT J AU Holland, M Kokkelmans, SJJMF Chiofalo, ML Walser, R AF Holland, M Kokkelmans, SJJMF Chiofalo, ML Walser, R TI Resonance superfluidity in a quantum degenerate Fermi gas SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN CONDENSATION; FESHBACH RESONANCES; ATOMIC GAS; LI-6 AB We consider the superfluid phase transition that arises when a Feshbach resonance pairing occurs in a dilute Fermi gas. We apply our theory to consider a specific resonance in potassium (K-40), and find that for achievable experimental conditions, the transition to a superfluid phase is possible at the high critical temperature of about 0.5T(F). Observation of superfluidity in this regime would provide the opportunity to experimentally study the crossover from the superfluid phase of weakly coupled fermions to the Bose-Einstein condensation of strongly bound composite bosons. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Scuola Normale Super Pisa, I-56126 Pisa, Italy. INFM, I-56126 Pisa, Italy. RP Holland, M (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 29 TC 455 Z9 457 U1 0 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2001 VL 87 IS 12 AR 120406 DI 10.1103/PhysRevLett.87.120406 PG 4 WC Physics, Multidisciplinary SC Physics GA 474TJ UT WOS:000171122700006 PM 11580493 ER PT J AU Weng, FZ Yan, BH Grody, NC AF Weng, FZ Yan, BH Grody, NC TI A microwave land emissivity model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SCATTERING MODEL; ROUGH SURFACE; SEA-SURFACE; VEGETATION; BACKSCATTERING; RETRIEVAL; FIELD; LAYER AB Satellite observations using microwave radiometers operating near the window regions are strongly affected by surface emissivity. Presently, the measurements obtained over land are not directly utilized in numerical weather prediction models because of uncertainties in estimating the emissivity. This study develops a new model to quantify the land emissivity over various surface conditions. For surfaces such as snow, deserts, and vegetation, volumetric scattering was calculated using a two-stream radiative transfer approximation. The reflection and transmission at the surface-air interface and lower boundary were derived by modifying the Fresnel equations to account for crosspolarization and surface roughness effects. Several techniques were utilized to compute the optical parameters for the medium, which is used in the radiative transfer solution. In the case of vegetation, geometrical optics is used because the leaf size is typically larger than the wavelength. For snow and deserts, a dense medium theory was adopted to take into account the coherent scattering of closely spaced particles. The emissivity spectra at frequencies between 4.9 and 94 GHz was simulated and compared with the ground-based radiometer measurements for bare soil, grass land, and snow conditions. It is shown that the features including the spectra, variability, and polarization agree well with the measurements. The simulated global distribution of land surface emissivity is also compared with the satellite retrievals from the Advanced Microwave Sounding Unit (AMSU). It is found that the largest discrepancies primarily occur over high latitudes where the snow properties are complex and least understood. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. Res & Data Syst Corp, Greenbelt, MD 20770 USA. RP Weng, FZ (reprint author), NOAA, NESDIS, Off Res & Applicat, 5200 Auth Rd,Rm 601, Camp Springs, MD 20746 USA. EM fweng@nesdis.noaa.gov RI Weng, Fuzhong/F-5633-2010 OI Weng, Fuzhong/0000-0003-0150-2179 NR 37 TC 104 Z9 117 U1 2 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 16 PY 2001 VL 106 IS D17 BP 20115 EP 20123 DI 10.1029/2001JD900019 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 473KZ UT WOS:000171044200009 ER PT J AU Schreiner, AJ Schmit, TJ Menzel, WP AF Schreiner, AJ Schmit, TJ Menzel, WP TI Observations and trends of clouds based on GOES sounder data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RETRIEVAL ALGORITHM; TOP HEIGHTS; VAS; SOUNDINGS; RADIANCE; COVER; ISCCP; HIRS AB A 26 month (November 1997 through December 1999) data set of Geostationary Operational Environmental Satellite (GOES) sounder-derived cloud parameters has been analyzed to discern annual and monthly trends. An important outcome of this study is the identification of diurnal trends made possible by the geostationary satellite frequent observations over specific locations. The area of coverage is 20 degreesN to 50 degreesN and 60 degreesW to 160 degreesW, which corresponds to the continental United States and the surrounding waters. The satellite cloud observations were compared to manually observed Pilot Reports (PIREPs) and were found to be, on average, 35 hPa lower. Comparing the frequency of GOES sounder observations of high cloudiness with observations from the National Oceanic and Atmospheric Administration (NOAA) series of polar orbiting weather satellites reveals a correlation coefficient of 0.79 and a bias of 3.4% for the frequency of occurrence (GOES with a mean higher height). The frequency of occurrence and distribution of clouds, cloud top pressure (CTOP), and effective cloud amount are based on a spatial resolution of similar to 40 km (3 x 3 field of view box) and are shown for eight regions. High clouds (CTOP less than or equal to 300 hPa) are found to be more prevalent during the Northern Hemisphere summer than winter for all regions. High clouds for 1998 comprise 8.5% of all observations. Also, in 1998 clear conditions are observed similar to 34% of the time. Focusing on the strength of the hourly GOES sounder data, it is found that thin high clouds are most prevalent during the summer and fall seasons, occurring most frequently in the late morning and early afternoon. C1 Univ Wisconsin, CIMSS, Madison, WI 53706 USA. NOAA, NESDIS, ORA, ASPT, Madison, WI USA. RP Schreiner, AJ (reprint author), Univ Wisconsin, CIMSS, 1225 W Dayton St, Madison, WI 53706 USA. EM tonys@ssec.wisc.edu RI Menzel, W. Paul/B-8306-2011; Schmit, Timothy/F-5624-2010 OI Menzel, W. Paul/0000-0001-5690-1201; NR 27 TC 27 Z9 27 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 SEP 16 PY 2001 VL 106 IS D17 BP 20349 EP 20363 DI 10.1029/2001JD900213 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 473KZ UT WOS:000171044200025 ER PT J AU Masarie, KA Langenfelds, RL Allison, CE Conway, TJ Dlugokencky, EJ Francey, RJ Novelli, PC Steele, LP Tans, PP Vaughn, B White, JWC AF Masarie, KA Langenfelds, RL Allison, CE Conway, TJ Dlugokencky, EJ Francey, RJ Novelli, PC Steele, LP Tans, PP Vaughn, B White, JWC TI NOAA/CSIRO Flask Air Intercomparison Experiment: A strategy for directly assessing consistency among atmospheric measurements made by independent laboratories SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-MONOXIDE; SAMPLING-NETWORK; 3-DIMENSIONAL SYNTHESIS; MIXING RATIOS; DELTA O-18; CO2; TROPOSPHERE; METHANE; VARIABILITY; HYDROGEN AB Since 1992, the National Oceanic and Atmospheric Administration (NOAA), Climate Monitoring and Diagnostics Laboratory of the United States and the Commonwealth Scientific and Industrial Research Organization (CSIRO), Division of Atmospheric Research of Australia have routinely analyzed the same air sample collected biweekly at Cape Grim, Tasmania. Comparisons of measurements of atmospheric CO2, CH4, CO, H-2, and the stable isotopes of CO2 (delta C-13, delta O-18) are used to assess the consistency of observations independently made by the two laboratories. Results demonstrate that conventional intercomparison strategies based on occasional exchange of high-pressure cylinders are not sufficient to ensure adequate comparability between flask data records. The NOAA/CSIRO flask air intercomparison experiment has higher time resolution and captures artifacts that are specific to flask measurements. This ongoing experiment provides a stringent quality control test of individual laboratories' experimental methods and internal calibration schemes, and is a valuable tool in working toward reliable integration of atmospheric data from independent laboratories. Results from the first 7 years of this intercomparison show that NOAA and CSIRO Cape Grim measurement records of CH4 are consistent to within 1 nmol mol(-1) (0.04%) and the CO2 records to similar to0.2 mu mol mol(-1) (0.06%). CH4 and CO2 observations from the two programs may be combined into more extensive data sets for specific purposes. Several causes of the observed differences in the measurements of delta C-13 and delta O-18 of CO2 have been identified and independently corroborated; combined data sets of these isotopomers appear possible. Possible explanations are provided for the observed differences in measurements of CO and H-2 from the same sample, which show significant variability with time. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. CSIRO Atmospher Res, Aspendale, Vic 3195, Australia. Monash Univ, Cooperat Res Ctr So Hemisphere Meteorol, Clayton, Vic 3168, Australia. Univ Colorado, Inst Arctic & Alpine Res, Boulder, CO 80309 USA. RP Masarie, KA (reprint author), NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. EM kmasarie@cmdl.noaa.gov RI Steele, Paul/B-3185-2009; White, James/A-7845-2009; Langenfelds, Raymond/B-5381-2012; OI Steele, Paul/0000-0002-8234-3730; White, James/0000-0001-6041-4684; VAUGHN, BRUCE/0000-0001-6503-957X NR 53 TC 58 Z9 62 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 16 PY 2001 VL 106 IS D17 BP 20445 EP 20464 DI 10.1029/2000JD000023 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 473KZ UT WOS:000171044200032 ER PT J AU Sidorkina, O Dizdaroglu, M Laval, J AF Sidorkina, O Dizdaroglu, M Laval, J TI Effect of single mutations on the specificity of Escherichia coli FPG protein for excision of purine lesions from DNA damaged by free radicals SO FREE RADICAL BIOLOGY AND MEDICINE LA English DT Article DE formamidopyrimidine N-DNA glycosylase; DNA repair; mass spectrometry; oxidative DNA damage; free radicals ID APURINIC APYRIMIDINIC SITES; IONIZING-RADIATION; SUBSTRATE-SPECIFICITY; CATALYTIC ACTIVITIES; STRAND BREAKS; NTH PROTEIN; GLYCOSYLASE; MECHANISM; REPAIR; 8-OXOGUANINE AB The formamidopyrimidine N-DNA glycosylase (Fpg protein) of Escherichia coli is a DNA repair enzyme that is specific for the removal of purine-derived lesions from DNA damaged by free radicals and other oxidative processes. We investigated the effect of single mutations on the specificity of this enzyme for three purine-derived lesions in DNA damaged by free radicals. These damaging agents generate a multiplicity of base products in DNA, with the yields depending on the damaging agent. Wild type Fpg protein (wt-Fpg) removes 8-hydroxyguanine (8-OH-Gua), 4,6-diamino-5-formamidopyrimidine (FapyAde), and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua) from damaged DNA with similar specificities. We generated five mutant forms of this enzyme with mutations involving Lys-57 --> Gly (FpgK57G), Lys-57 --> Arg (FpgK57R), Lys-155 --> Ala (FpaK155A), Pro-2 --> Gly (FpgP2G), and Pro-2 --> Gln (FpgP2E), and purified them to homogeneity. FpgK57G and FpgK57R were functional for removal of FapyAde and FapyGua with a reduced activity when compared with wt-Fpa. The removal of 8-OH-Gua was different in that the specificity of FpgK57G was significantly lower for its removal from irradiated DNA, whereas wt-Fpg, FpgK57G, and FpgK57R excised 8-OH-Gua from H2O2/Fe(III)-EDTA/ascorbic acid-treated DNA with almost the same specificity. FpgK155A and FpgP2G had very low activity and FpgP2E exhibited no activity at all. Michaelis-Menten kinetics of excision was measured and kinetic constants were obtained. The results indicate an important role of Lys-57 residue in the activity of Fpg protein for 8-OH-Gua, but a lesser significant role for formamidopyrimidines. Mutations involving Lys-155 and Pro-2 had a dramatic effect with Pro-2 --> Glu leading to complete loss of activity, indicating a significant role of these residues. The results show that point mutations significantly change the specificity of Fpg protein and suggest that point mutations are also expected to change specificities of other DNA repair enzymes. (C) 2001 Elsevier Science Inc. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Inst Gustave Roussy, Grp Reparat ADN, Villejuif, France. RP Dizdaroglu, M (reprint author), NIST, Chem Sci & Technol Lab, Bldg 227-A243,Mail Stop 8311, Gaithersburg, MD 20899 USA. NR 37 TC 8 Z9 8 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0891-5849 J9 FREE RADICAL BIO MED JI Free Radic. Biol. Med. PD SEP 15 PY 2001 VL 31 IS 6 BP 816 EP 823 DI 10.1016/S0891-5849(01)00659-1 PG 8 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 474TZ UT WOS:000171124100014 PM 11557320 ER PT J AU Hayes, ML Bonaventura, J Mitchell, TP Prospero, JM Shinn, EA Van Dolah, F Barber, RT AF Hayes, ML Bonaventura, J Mitchell, TP Prospero, JM Shinn, EA Van Dolah, F Barber, RT TI How are climate and marine biological outbreaks functionally linked? SO HYDROBIOLOGIA LA English DT Article DE disease; dust; HABs; iron; NAO; pathogen ID NORTH-ATLANTIC OSCILLATION; EQUATORIAL PACIFIC-OCEAN; EASTERN UNITED-STATES; AFRICAN DUST; SAHARAN DUST; TROPICAL ATLANTIC; MINERAL DUST; PRIMARY PRODUCTIVITY; INFECTIOUS-DISEASE; BACTERIAL-GROWTH AB Since the mid-1970s, large-scale episodic events such as disease epidemics, mass mortalities, harmful algal blooms and other population explosions have been occurring in marine environments at an historically unprecedented rate. The variety of organisms involved (host. pathogens and other opportunists) and the absolute number of episodes have also increased during this period, Are these changes coincidental? Between 1972 and 1976, a global climate regime shift took place, and it is manifest most clearly by a change in strength of the North Pacific and North Atlantic Pressure systems. Consequences of this regime shift arc: (1) prolonged drought conditions in the Sahel region of Africa: (2) increased dust supply to the global atmosphere, by a factor of approximately Four; 3) increased easterly trade winds across the Atlantic; (4) increased colian transport of dust to the Atlantic and Caribbean basins; and (5) increased deposition of iron-rich colian dust to typically iron-poor marine regions. On the basis of well-documented climate and dust observations and the widely accepted increase in marine outbreak rates, this paper proposes that the increased iron supply has altered the micronutrient factors limiting growth of opportunistic organisms and virulence of pathogenic microbes, particularly in macronutrient-rich coastal systems. C1 Duke Univ, Marine Lab, Beaufort, NC 28516 USA. Univ Washington, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98195 USA. Univ Miami, Cooperat Inst Marine & Atmospher Studies, Miami, FL 33149 USA. USGS Ctr Coastal Geol, St Petersburg, FL 33701 USA. NOAA, Ctr Coastal Environm Hlth & Biomol Res, Charleston, SC 29412 USA. RP Hayes, ML (reprint author), Duke Univ, Marine Lab, Beaufort, NC 28516 USA. OI Prospero, Joseph/0000-0003-3608-6160 NR 91 TC 53 Z9 55 U1 2 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD SEP 15 PY 2001 VL 460 BP 213 EP 220 DI 10.1023/A:1013121503937 PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 511DJ UT WOS:000173249100020 ER PT J AU Sobolewski, MA AF Sobolewski, MA TI Measuring the ion current in high-density plasmas using radio-frequency current and voltage measurements SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INDUCTIVELY-COUPLED PLASMA; PULSED RADIOFREQUENCY DISCHARGES; CAPACITIVE RF SHEATH; ELECTRICAL CHARACTERISTICS; ENERGY-DISTRIBUTIONS; REFERENCE CELL; IMPEDANCE MEASUREMENTS; PARAMETER ANALYSIS; ARGON; ALUMINUM AB The total current or flux of ions striking the substrate is an important parameter that must be tightly controlled during plasma processing. Several methods have recently been proposed for monitoring the ion current in situ. These methods rely on passive, noninvasive measurements of the radio frequency (rf) current and voltage signals that are generated by plasma-processing equipment. The rf measurements are then interpreted by electrical models of the plasma discharge. Here, a rigorous and comprehensive test of such methods was performed for high-density discharges in argon at 1.33 Pa (10 mTorr) in an inductively coupled plasma reactor, at inductive source powers of 60-350 W, rf bias powers up to 150 W, and rf bias frequencies of 0.1-10 MHz. Model-based methods were tested by comparison to direct, independent measurements of the ion current at the substrate electrode made using lower frequency (10 kHz) rf bias and modulated rf bias. Errors in two model-based methods are identified and explained by effects that are present in the high-density plasmas but are not included in the models. A third method, based on a new, more accurate numerical sheath model, gives values of the ion current in agreement with the independent measurements. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sobolewski, MA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 40 TC 31 Z9 32 U1 1 U2 11 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 2001 VL 90 IS 6 BP 2660 EP 2671 DI 10.1063/1.1390491 PG 12 WC Physics, Applied SC Physics GA 466LR UT WOS:000170647500005 ER PT J AU Wang, CZ Weisberg, RH AF Wang, CZ Weisberg, RH TI Ocean circulation influences on sea surface temperature in the equatorial central Pacific SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEASONAL CYCLE; ATLANTIC-OCEAN; VARIABILITY; HEAT; TURBULENCE; MOMENTUM; FLUXES; WAVES AB Velocity data from an array of acoustic Doppler current profilers moored about 0 degrees, 140 degreesW from May 1990 through June 1991 during the Tropical Instability Wave Experiment are used in conjunction with Tropical Atmosphere-Ocean array data and a blended sea surface temperature (SST) product to study the processes that control SST variations. The horizontal velocity data allow us to calculate the vertical velocity component by vertically integrating the continuity equation. Given the three-dimensional temperature flux divergence, we examine the role of the ocean circulation in SST. Upwelling and downwelling are found to be associated with cooling and warming, respectively, suggesting that a vertical velocity component of either sign affects SST. Both the temperature flux divergence and advective formulations for the ocean circulation's influence on the temperature budget show times when the ocean circulation appears to provide the primary control on SST and times when this is not the case, with the flux divergence formulation performing better than the advective formulation. Statistically, within a bandwidth encompassing the tropical instability waves and the intraseasonal variations, roughly half of the SST variation is accounted for by the ocean circulation. These results are encouraging, given that data sets with different spatial and temporal scales have been used. They suggest that future field experimentation which utilizes a flux divergence array with velocity and temperature data sampled at the same spatial and temporal scales will yield quantitatively improved results. The analyses also show that the ocean circulation, on average, provides a cooling effect requiring the net surface heat flux to be positive to maintain the mean background state. The cooling effect is mainly controlled by mean ocean circulation and temperature fields. C1 NOAA, Atlantic Oceanog & Meteorol Lab, PhOD, Miami, FL 33149 USA. Univ S Florida, Coll Marine Sci, St Petersburg, FL 33701 USA. RP Wang, CZ (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, PhOD, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Wang, Chunzai /C-9712-2009 OI Wang, Chunzai /0000-0002-7611-0308 NR 34 TC 7 Z9 8 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP 15 PY 2001 VL 106 IS C9 BP 19515 EP 19526 DI 10.1029/2000JC000242 PG 12 WC Oceanography SC Oceanography GA 471YT UT WOS:000170956800002 ER PT J AU Beletsky, D Schwab, DJ AF Beletsky, D Schwab, DJ TI Modeling circulation and thermal structure in Lake Michigan: Annual cycle and interannual variability SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID GREAT-LAKES; NUMERICAL-MODELS; MIXED-LAYER; ICE CONDITIONS; OCEAN MODEL; SIMULATION; TEMPERATURE; SEA; VERIFICATION; WEATHER AB A three-dimensional primitive equation numerical model was applied to Lake Michigan for the periods 1982-1983 and 1994-1995 to study seasonal and interannual variability of lake-wide circulation and thermal structure in the lake. The model was able to reproduce all of the basic features of the thermal structure in Lake Michigan: spring thermal bar, full stratification, deepening of the thermocline during the fall cooling, and finally, an overturn in the late fall. Large-scale circulation patterns tend to be cyclonic (counterclockwise), with cyclonic circulation within each subbasin. The largest currents and maximum cyclonic vorticity occur in the fall and winter when temperature gradients are low but wind stresses are strongest. The smallest currents and minimum cyclonic vorticity occur in spring and summer when temperature gradients are strong but wind stresses are weakest. All these facts are in agreement with observations. The main shortcoming of the model was that it tended to predict a more diffuse thermocline than was indicated by observations and explained only up to half of the variance observed in horizontal currents at timescales shorter than a day. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Michigan, Dept Naval Architecture & Marine Engn, Ann Arbor, MI 48109 USA. RP Beletsky, D (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. RI Schwab, David/B-7498-2012; OI Beletsky, Dmitry/0000-0003-4532-0588 NR 59 TC 98 Z9 99 U1 2 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP 15 PY 2001 VL 106 IS C9 BP 19745 EP 19771 DI 10.1029/2000JC000691 PG 27 WC Oceanography SC Oceanography GA 471YT UT WOS:000170956800016 ER PT J AU Smith, AP Douglas, JF Meredith, JC Amis, EJ Karim, A AF Smith, AP Douglas, JF Meredith, JC Amis, EJ Karim, A TI High-throughput characterization of pattern formation in symmetric diblock copolymer films SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE combinatorial measurements; block copolymer; thin film; surface pattern ID ASSEMBLED MONOLAYER GROWTH; THIN-FILMS; FREE-SURFACE; MICROPHASE SEPARATION; BENDING ELASTICITY; FLUID MEMBRANES; SHEAR VISCOSITY; BLEND FILMS; KINETICS; DOMAINS AB Surface-pattern formation in thin block copolymer films was investigated by utilizing a high-throughput methodology to validate the combinatorial measurement approach and to demonstrate the value of the combinatorial method for scientific investigation. We constructed measurement libraries from images of subregions of block copolymer films having gradients in film thickness and a range of molecular mass, M. A single gradient film covers a wide range of film morphologies and contains information equivalent to a large number of measurements of films having a fixed thickness, h. Notably, the scale of the surface patterns is generally much larger than the molecular dimensions so that the interpretation of the patterns is more subtle than ordering in bulk block copolymer materials, and there is no predictive theory of this type of surface-pattern formation. We observed a succession of surface patterns that repeat across the film with increasing h [extended smooth regions, regions containing circular islands, labyrinthine ("spinodal") patterns, holes, and smooth regions again]. The extended smooth regions and the labyrinthine patterns appear to be novel features revealed by our combinatorial study, and these patterns occurred as bands of h that were quantized by integral multiples of the bulk lamellar period, L-o. The magnitude of the height gradient influenced the width of the bands, and the smooth regions occupied an increasing fraction of the film-surface area with an increasing film gradient. The average size of the spinodal patterns, lambda, was found to scale as lambda similar to L-o(- 2.5) or lambda similar to M-1.65 and reached a limiting size at long annealing times. The hole and island features had a size comparable to lambda, and their size likewise decreased with increasing M. The smooth regions were attributed to an increase in the surface-chain density in the outer brushlike block copolymer layer with increasing h, and the scaling of lambda with M was interpreted in terms of the increasing surface elasticity with M. (C) 2001 John Wiley & Sons, Inc. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Karim, A (reprint author), Natl Inst Stand & Technol, Div Polymers, Mail Stop 8542, Gaithersburg, MD 20899 USA. RI Meredith, Carson/B-3323-2009 OI Meredith, Carson/0000-0003-2519-5003 NR 70 TC 67 Z9 67 U1 0 U2 15 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 15 PY 2001 VL 39 IS 18 BP 2141 EP 2158 DI 10.1002/polb.1188 PG 18 WC Polymer Science SC Polymer Science GA 465XF UT WOS:000170614700001 ER PT J AU Kepa, H Kutner-Pielaszek, J Twardowski, A Majkrzak, CF Sadowski, J Story, T Giebultowicz, TM AF Kepa, H Kutner-Pielaszek, J Twardowski, A Majkrzak, CF Sadowski, J Story, T Giebultowicz, TM TI Ferromagnetism of GaMnAs studied by polarized neutron reflectometry SO PHYSICAL REVIEW B LA English DT Article ID III-V SEMICONDUCTORS AB Polarized neutron reflectometry has been used to investigate details of spin ordering in ferromagnetic (FM) GaMnAs/GaAs superlattices. The reflectivity spectra measured below the Curie temperature reveal additional magnetic contributions to the structural superlattice Bragg peaks, clearly indicating the existence of FM interlayer correlations. Closer investigation of the magnetic reflectivity maxima using a full polarization analysis provides direct evidence that the FM order is the GaMnAs layers is truly long range. Moreover, as shown by the data, the system exhibits a strong tendency of forming a single-domain FM arrangement, even when cooled through Tc in zero external field. C1 Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. Chalmers Univ Technol, Dept Expt Phys, SE-41296 Gothenburg, Sweden. Univ Gothenburg, SE-41296 Gothenburg, Sweden. Oregon State Univ, Dept Phys, Corvallis, OR 97331 USA. RP Kepa, H (reprint author), Univ Warsaw, Inst Expt Phys, Hoza 69, PL-00681 Warsaw, Poland. RI Sadowski, Janusz/E-9464-2014 OI Sadowski, Janusz/0000-0002-9495-2648 NR 15 TC 43 Z9 44 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 121302 PG 4 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400011 ER PT J AU Woicik, JC Nelson, EJ Heskett, D Warner, J Berman, LE Karlin, BA Vartanyants, IA Hasan, MZ Kendelewicz, T Shen, ZX Pianetta, P AF Woicik, JC Nelson, EJ Heskett, D Warner, J Berman, LE Karlin, BA Vartanyants, IA Hasan, MZ Kendelewicz, T Shen, ZX Pianetta, P TI X-ray standing-wave investigations of valence electronic structure SO PHYSICAL REVIEW B LA English DT Article ID SURFACE-STRUCTURE DETERMINATION; PHOTOELECTRON-SPECTROSCOPY; PHOTOEMISSION SPECTRA; PARTIAL DENSITY; CROSS-SECTIONS; COOPER-MINIMUM; NIO; STATES; ALLOYS; DIFFRACTION AB We have examined the valence-electron emission from Cu, Ge, GaAs, InP, and NiO single crystals under the condition of strong x-ray Bragg reflection; i.e., in the presence of the spatially modulated x-ray standing-wave interference field that is produced by the superposition of the incident and reflected x-ray beams. These crystals span the entire metallic, covalent, and ionic range of solid-state bonding. It is demonstrated that the valence-electron emission is closely coupled to the atomic cores, even for electron states close to a metallic Fermi edge. Using the bond-orbital approximation, the x-ray standing-wave structure factor for valence-electron emission is derived in terms of the bond polarities and photoionization cross sections of the atoms within the crystalline unit cell and compared to experiment. Additionally, we demonstrated that by exploiting the spatial dependence of the electric-field intensity under Bragg condition, site specific valence electronic structure may be obtained. The technique is demonstrated for GaAs and NiO. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Rhode Isl, Dept Phys, Kingston, RI 02881 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Woicik, JC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI HASAN, M. Zahid/D-8237-2012 NR 60 TC 24 Z9 24 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 125115 DI 10.1103/PhysRevB.64.125115 PG 15 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400038 ER PT J AU Hogan, CJ Bender, PL AF Hogan, CJ Bender, PL TI Estimating stochastic gravitational wave backgrounds with the Sagnac calibration SO PHYSICAL REVIEW D LA English DT Article ID DOUBLE WHITE-DWARFS; EXTRAGALACTIC BINARIES; LISA; RADIATION; INTERFEROMETER; NOISE AB Armstrong et al. have recently presented new ways of combining signals to precisely cancel laser frequency noise in spaceborne interferometric gravitational wave detectors such as LISA. One of these combinations, which we will call the "symmetrized Sagnac observable," is much less sensitive to external signals at low frequencies than other combinations, and thus can be used to determine the instrumental noise level. We note here that this calibration of the instrumental noise permits smoothed versions of the power spectral density of stochastic gravitational wave backgrounds to be determined with considerably higher accuracy than earlier estimates, at frequencies where one type of noise strongly dominates and is not substantially correlated between the six main signals generated by the antenna. We illustrate this technique by analyzing simple estimators of gravitational wave background power. and show that the instrumental sensitivity to broad-band backgrounds at some frequencies can be improved by a significant factor of as much as (f tau /2)(1/2) in spectral density h(rms)(2) over the standard method, where f denotes frequency and tau denotes integration time, comparable to that which would be achieved by cross-correlating two separate antennas. The applications of this approach to studies of astrophysical gravitational wave backgrounds generated after recombination and to searches for a possible primordial background are discussed. With appropriate mission design, this technique allows an estimate of the cosmological background from extragalactic white dwarf binaries and will enable LISA to reach the astrophysical confusion noise of compact binaries from about 0.1 mHz to about 20 mHz. In a smaller-baseline follow-on mission, the technique allows several orders of magnitude improvement in sensitivity to primordial backgrounds up to about 1 Hz. C1 Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Hogan, CJ (reprint author), Univ Washington, Dept Astron, Seattle, WA 98195 USA. NR 32 TC 37 Z9 38 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 2001 VL 64 IS 6 AR 062002 DI 10.1103/PhysRevD.64.062002 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 472HN UT WOS:000170978200004 ER PT J AU Reddy, SK Kamireddi, M Dhanireddy, K Young, L Davis, A Reddy, PT AF Reddy, SK Kamireddi, M Dhanireddy, K Young, L Davis, A Reddy, PT TI Eukaryotic-like adenylyl cyclases in Mycobacterium tuberculosis H37Rv - Cloning and characterization SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID GENE-PRODUCTS; CYCLIC-AMP; PROTEIN; EXPRESSION; RESISTANCE; HEMOLYSIN; APOPTOSIS; INFECTION; SEQUENCE; DOMAINS AB Screening the Mycobacterium tuberculosis H37Rv genomic library for complementation of catabolic defect for cAMP-dependent expression of maltose operon produced the adenylyl cyclase gene (Mtb cya, GenBank(TM) accession no. AF017731 (1997)) annotated later as Rv1625c (Cole, S. T., Brosch, R., Parkhill, J., Garnier, T., Churcher, C., Harris, D., Gordon, S. V., Eiglmeier, K., Gas, S., Barry, C. E., III, et al. (1998) Nature 393, 537-544). The deduced amino acid (aa) sequence (443 aa) encoded by Mtb cya contains a single hydrophobic domain of six transmembrane helices (152 aa) in the amino-terminal half of the protein. Flanking this domain are an arginine-rich (17%) amino-terminal cytoplasmic tail (46 aa) and a carboxyl-terminal cytoplasmic domain (245 aa) with extensive homology to the catalytic core of eukaryotic adenylyl cyclases. Site-directed mutagenesis of Arg(43) and Arg(44) to alanine/glycine showed a loss of adenylyl cyclase activity, whereas mutagenesis to lysine restored the activity. Hence it is proposed that the formation of the catalytic site in Mtb adenylyl cyclase requires an interaction between Arg(43) and Arg(44) residues in the distal cytoplasmic tail and the carboxyl-terminal cytoplasmic domain. Mtb adenylyl cyclase activity at the physiological concentration of ATP (1 mm) was 475 nmol of cAMP/min/mg of membrane protein in the presence of Mn2+ but only 10 nmol of cAMP/min/mg of membrane protein in the presence of Mg2+. The physiological significance of the activation of Mtb adenylyl cyclase by Mn2+ is discussed in view of the presence of manganese transporter protein in mycobacteria and macrophages wherein mycobacteria reside. C1 NIST, Chem Sci & Technol Lab, Div Biotechnol, DNA Technol Grp, Gaithersburg, MD 20899 USA. RP Reddy, PT (reprint author), NIST, Chem Sci & Technol Lab, Div Biotechnol, DNA Technol Grp, Bldg 227,Rm B244,Mail Stop 831-1,100 Bur Dr, Gaithersburg, MD 20899 USA. NR 35 TC 38 Z9 41 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 14 PY 2001 VL 276 IS 37 BP 35141 EP 35149 DI 10.1074/jbc.M104108200 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 473DK UT WOS:000171024600104 PM 11431477 ER PT J AU Smith, ACH Bannister, ME Chung, YS Djuric, N Dunn, GH Neau, A Popovic, D Stepanovic, M Wallbank, B AF Smith, ACH Bannister, ME Chung, YS Djuric, N Dunn, GH Neau, A Popovic, D Stepanovic, M Wallbank, B TI Excitation of He(+) to the 2 (2)S and 2 (2)P states by electron impact SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID CLOSE-COUPLING CALCULATIONS; ENERGY-LOSS TECHNIQUE; CROSS-SECTIONS; N=3 LEVEL; 2S STATE; SCATTERING; BEAMS; IONS; AUTOIONIZATION; TRANSITIONS AB The first absolute measurement of the cross section for excitation of a hydrogenlike ion is reported. The combined cross section for electron impact excitation of ground state He(+) to the 2 (2)S and 2 (2)P excited states has been measured in the near-threshold region from 40.08 to 41.95 eV using the JILA/ORNL merged electron-ion beams energy-loss technique. The threshold step in the cross section is measured as (8.46 +/-1.52) x 10(-18) cm(2) at 90% confidence level of total uncertainty, which is approximately 20% larger than values calculated using close-coupling and variational methods. This contrasts with the longstanding disparity of nearly a factor of two between theory and normalized experiment fur excitation to the 2 (2)S state. C1 UCL, Dept Phys & Astron, London WC1E 6BT, England. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Chungnam Natl Univ, Dept Phys, Taejon 305764, South Korea. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Stockholm, Dept Phys, S-11385 Stockholm, Sweden. St Francis Xavier Univ, Antigonish, NS B2G 2W5, Canada. RP Smith, ACH (reprint author), UCL, Dept Phys & Astron, Mortimer St, London WC1E 6BT, England. EM banniste@mail.phy.ornl.gov NR 20 TC 7 Z9 7 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 14 PY 2001 VL 34 IS 17 BP L571 EP L577 DI 10.1088/0953-4075/34/17/104 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 482KA UT WOS:000171574300004 ER PT J AU Read, DT Cheng, YW Keller, RR McColskey, JD AF Read, DT Cheng, YW Keller, RR McColskey, JD TI Tensile properties of free-standing aluminum thin films SO SCRIPTA MATERIALIA LA English DT Article DE aluminum thin film; digital-image correlation; electron-beam deposition; mechanical properties; tensile properties ID DIGITAL IMAGE CORRELATION; STRENGTH C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Cheng, YW (reprint author), Natl Inst Stand & Technol, Boulder, CO 80305 USA. RI Keller, Robert/I-9014-2012 NR 19 TC 58 Z9 58 U1 0 U2 9 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 SEP 12 PY 2001 VL 45 IS 5 BP 583 EP 589 DI 10.1016/S1359-6462(01)01067-3 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 477WJ UT WOS:000171307000013 ER PT J AU Lee, JH Balsara, NP Krishnamoorti, R Jeon, HS Hammouda, B AF Lee, JH Balsara, NP Krishnamoorti, R Jeon, HS Hammouda, B TI Designing balanced surfactants for mixtures of immiscible polymers SO MACROMOLECULES LA English DT Article ID MULTICOMPONENT POLYOLEFIN BLENDS; PHASE-BEHAVIOR; THERMODYNAMIC PROPERTIES; MICROEMULSIONS; SYSTEMS; MICROSTRUCTURE C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Houston, Dept Chem Engn, Houston, TX 77204 USA. New Mexico Inst Min & Technol, Dept Chem & Petr Engn, Socorro, NM 87801 USA. NIST, Gaithersburg, MD 20899 USA. RP Balsara, NP (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RI Krishnamoorti, Ramanan/F-7914-2011 OI Krishnamoorti, Ramanan/0000-0001-5831-502X NR 18 TC 26 Z9 26 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 11 PY 2001 VL 34 IS 19 BP 6557 EP 6560 DI 10.1021/ma011038e PG 4 WC Polymer Science SC Polymer Science GA 470CU UT WOS:000170853500011 ER PT J AU Grohn, F Bauer, BJ Amis, EJ AF Grohn, F Bauer, BJ Amis, EJ TI Hydrophobically modified dendrimers as inverse micelles: Formation of cylindrical multidendrimer nanostructures SO MACROMOLECULES LA English DT Article ID SMALL-ANGLE SCATTERING; POLY(PROPYLENE IMINE) DENDRIMERS; INDIRECT TRANSFORMATION METHOD; NEUTRON-SCATTERING; WATER; GENERATION; PERIPHERY; COMPLEXES; CORE AB Poly(propyleneimine) dendrimers with stearyl end groups are investigated as inverse micelles in toluene. While the initial dendrimers have a spherical structure with a collapsed core, solubilization of metal salt hydrate leads to the formation of cylindrical multidendrimer structures with swollen, metal-salt-filled dendrimer cores. The cylindrical structure can be deduced from the small-angle neutron (SANS) as well as from the X-ray scattering (SAXS) pair distance distribution function. While the neutron scattering leads to a two-step cross-sectional density profile, the X-ray scattering is sensitive only to the metal-salt-stained core. The gold salt inside the dendrimers was reduced to form colloidal particles, and upon reduction the cylindrical structure breaks up and spherical colloids are formed. The sizes are larger than would be expected if the gold salt loading of one dendrimer formed one particle, indicating that the ions from several dendrimers are combined. These dendrimer-stabilized metal colloids represent hybrid structures that have potential importance as selective catalysts and in the formation of composite materials with special optical properties. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Amis, EJ (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 40 TC 29 Z9 29 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 11 PY 2001 VL 34 IS 19 BP 6701 EP 6707 DI 10.1021/ma0017384 PG 7 WC Polymer Science SC Polymer Science GA 470CU UT WOS:000170853500030 ER PT J AU Simpson, JJ McIntire, TJ Stitt, JR Hufford, GL AF Simpson, JJ McIntire, TJ Stitt, JR Hufford, GL TI Improved cloud detection in AVHRR daytime and night-time scenes over the ocean SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID TRACK SCANNING RADIOMETER; SEA-SURFACE; CONTAMINATION; IMAGERY; REMOVAL; SEGMENTATION; RADIANCES; ALGORITHM; SYSTEM; LAND AB Accurate cloud detection is a requirement of many geophysical applications that use visible and infrared satellite data (e.g. cloud climatologies, multichannel sea surface temperature (MCSST)). Unfortunately, a significant source of residual error in such satellite-based products is undetected cloud. Here. a new, computationally efficient cloud detection procedure for both daytime and nighttime Advanced Very High Resolution Radiometer (AVHRR) data is developed. It differs substantially from our prior related work. First, a new clustering procedure is used, which produces more homogeneous and distinct clusters than those produced by either our previous work or the ISODATA algorithm of Ball and Hall. Second, the input information vector is reduced in size, incorporates both radiance and spatial components and each component is normalized. These changes improve the clustering/subsequent classification, tend to decrease execution time. and simplify post-processing of the classified (cloud, clear ocean) data to remove any residual outliers. Third, the enhanced performance makes possible the use of a multipass procedure which is very effective in identifying the complex multilayer cloud structures common in satellite data. Validation with independent lidar observations confirms the accuracy of the new procedure. Marine low stratiform clouds (LSCs-fog, stratus and stratocumulus) are also detected effectively. This advance is important because LSCs are a major source of residual cloud contamination in contemporary sea surface temperature (SST) products. Finally, the method is sufficiently general that it can be adapted to other sensors (e.g. the Along-Track Scanning Radiometer (ATSR), the Moderate Resolution Imaging Spectroradiometer (MODIS)). C1 Univ Calif San Diego, Scripps Inst Oceanog, Digital Image Anal Lab, La Jolla, CA 92093 USA. US Natl Weather Serv, Alaska Reg Headquarters, Anchorage, AK USA. RP Simpson, JJ (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Digital Image Anal Lab, La Jolla, CA 92093 USA. NR 43 TC 16 Z9 20 U1 0 U2 6 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD SEP 10 PY 2001 VL 22 IS 13 BP 2585 EP 2615 DI 10.1080/01431160119916 PG 31 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 464WU UT WOS:000170557000010 ER PT J AU Papanek, P Kamitakahara, WA Zhou, P Fischer, JE AF Papanek, P Kamitakahara, WA Zhou, P Fischer, JE TI Neutron scattering studies of disordered carbon anode materials SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID LITHIUM INSERTION; LOCAL-STRUCTURE; INTERCALATION; SPECTROSCOPY; POLYMERS AB Carbon-based anodes show many promising properties in lithium-ion rechargeable batteries. So-called 'disordered carbons' are characterized by a substantial amount of residual hydrogen, and exhibit large Li uptake capacities. We have employed a variety of neutron scattering techniques, coupled with computer simulations, to study the composition, local atomic structure, and vibrational dynamics of such materials. Radial distribution function analysis of neutron diffraction data, and incoherent inelastic scattering show that the structural motif is a planar graphene fragment, with edge carbons terminated by single hydrogen atoms, and random stacking between fragments. The vibrational spectra of the hydrogen-rich carbons are remarkably similar to the spectra of the polycyclic aromatic hydrocarbon coronene in the medium-frequency region. At low frequencies, only a boson peak is observed, characteristic for glassy and disordered materials, and this feature shifts upon doping. The results are consistent with two proposed mechanisms for Li capacity, one analogous to conventional intercalation but with Li on both sides of graphene fragments, the other involving bonding of Li to H-terminated edge carbons. C1 Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Penn, Res Struct Matter Lab, Philadelphia, PA 19104 USA. RP Papanek, P (reprint author), Univ Penn, Dept Mat Sci & Engn, 3231 Walnut St, Philadelphia, PA 19104 USA. NR 24 TC 12 Z9 12 U1 5 U2 15 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 SEP 10 PY 2001 VL 13 IS 36 BP 8287 EP 8301 DI 10.1088/0953-8984/13/36/305 PG 15 WC Physics, Condensed Matter SC Physics GA 482KC UT WOS:000171574500007 ER PT J AU Gulseren, O Yildirim, T Ciraci, S AF Gulseren, O Yildirim, T Ciraci, S TI Tunable adsorption on carbon nanotubes SO PHYSICAL REVIEW LETTERS LA English DT Article ID SINGLE; MICROTUBULES; TEMPERATURE; HYDROGEN; STORAGE AB We investigated the adsorption of a single atom, hydrogen and aluminum, on single-wall carbon nanotubes from first principles. The adsorption is exothermic, and the associated binding energy varies inversely as the radius of the zigzag tube. We found that the adsorption of a single atom and related properties can be modified continuously and reversibly by the external radial deformation. The binding energy on the high curvature site of the deformed tube increases with increasing radial deformation. The effects of curvature and radial deformation depend on the chirality of the tube. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. Bilkent Univ, Dept Phys, TR-06533 Ankara, Turkey. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. RP Gulseren, O (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI yildirim, taner/A-1290-2009 NR 20 TC 169 Z9 170 U1 0 U2 16 PU AMER 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 SEP 10 PY 2001 VL 87 IS 11 AR 116802 DI 10.1103/PhysRevLett.87.116802 PG 4 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600036 PM 11531543 ER PT J AU Irikura, KK AF Irikura, KK TI Thermochemistry of disulfur decafluoride, S2F10 (vol 103, pg 10162, 1995) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Correction C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Irikura, KK (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Irikura, Karl/A-4266-2009 OI Irikura, Karl/0000-0001-7515-6761 NR 2 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 2001 VL 115 IS 10 BP 4966 EP 4966 DI 10.1063/1.1394746 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 466LT UT WOS:000170647600062 ER PT J AU Nowacek, DP Johnson, MP Tyack, PL Shorter, KA McLellan, WA Pabst, DA AF Nowacek, DP Johnson, MP Tyack, PL Shorter, KA McLellan, WA Pabst, DA TI Buoyant balaenids: the ups and downs of buoyancy in right whales SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE Eubalaena glacialis; buoyancy; tagging; diving behaviour; conservation ID NORTHERN ELEPHANT SEALS; PHOCOENA-PHOCOENA; HARBOR PORPOISES; DIVING BEHAVIOR; DOLPHINS AB A variety of marine mammal species have been shown to conserve energy by using negative buoyancy to power prolonged descent glides during dives. A new non-invasive tag attached to North Atlantic right whales recorded swim stroke from changes in pitch angle derived from a three-axis accelerometer. These results show that right whales are positively buoyant near the surface, a finding that has significant implications for both energetics and management. Some of the most powerful fluke strokes observed in tagged right whales occur as they counteract this buoyancy as they start a dive. By contrast, right whales use positive buoyancy to power glides during ascent. Right whales appear to use their positive buoyancy for more efficient swimming and diving. However, this buoyancy may pose added risks of vessel collision. Such collisions are the primary source of anthropogenic mortality for North Atlantic right whales, whose population is critically endangered and declining. Buoyancy may impede diving responses to oncoming vessels and right whales may have a reduced ability to manoeuvre during free ascents. These risk factors can inform efforts to avoid collisions. C1 Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. NE Fisheries Sci Ctr, Large Whale Biol Program, Woods Hole, MA 02543 USA. Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. Univ N Carolina, Dept Biol Sci, Wilmington, NC 28403 USA. RP Nowacek, DP (reprint author), Woods Hole Oceanog Inst, 45 Water St, Woods Hole, MA 02543 USA. EM dnowacek@whoi.edu RI Tyack, Peter/D-6209-2013 OI Tyack, Peter/0000-0002-8409-4790 NR 40 TC 65 Z9 68 U1 2 U2 19 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD SEP 7 PY 2001 VL 268 IS 1478 BP 1811 EP 1816 PG 6 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA 469UN UT WOS:000170834600009 PM 11522200 ER PT J AU Steinle-Neumann, G Stixrude, L Cohen, RE Gulseren, O AF Steinle-Neumann, G Stixrude, L Cohen, RE Gulseren, O TI Elasticity of iron at the temperature of the Earth's inner core SO NATURE LA English DT Article ID SITU X-RAY; HIGH-PRESSURE; IN-SITU; ANISOTROPY; TRANSITION; MODEL; GPA AB Seismological body-wave(1) and free-oscillation(2) studies of the Earth's solid inner core have revealed that compressional waves traverse the inner core faster along near-polar paths than in the equatorial plane. Studies have also documented local deviations from this first-order pattern of anisotropy on length scales ranging from 1 to 1,000 km (refs 3, 4). These observations, together with reports of the differential rotation(5) of the inner core, have generated considerable interest in the physical state and dynamics of the inner core, and in the structure and elasticity of its main constituent, iron, at appropriate conditions of pressure and temperature. Here we report first-principles calculations of the structure and elasticity of dense hexagonal close-packed (h.c.p.) iron at high temperatures. We find that the axial ratio c/a of h.c.p. iron increases substantially with increasing temperature, reaching a value of nearly 1.7 at a temperature of 5,700 K, where aggregate bulk and shear moduli match those of the inner core. As a consequence of the increasing c/a ratio, we have found that the single-crystal longitudinal anisotropy of h.c.p. iron at high temperature has the opposite sense from that at low temperature(6,7). By combining our results with a simple model of polycrystalline texture in the inner core, in which basal planes are partially aligned with the rotation axis, we can account for seismological observations of inner-core anisotropy. C1 Univ Michigan, Dept Geol Sci, Ann Arbor, MI 48109 USA. Carnegie Inst Washington, Washington, DC 20015 USA. Ctr High Pressure Res, Washington, DC 20015 USA. CALTECH, Seismol Lab, Pasadena, CA 91125 USA. NIST, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. RP Steinle-Neumann, G (reprint author), Univ Michigan, Dept Geol Sci, 1006 CC Little Bldg, Ann Arbor, MI 48109 USA. RI Cohen, Ronald/B-3784-2010; Stixrude, Lars/C-5625-2012; Steinle-Neumann, Gerd/D-8805-2012 OI Cohen, Ronald/0000-0001-5871-2359; Stixrude, Lars/0000-0003-3778-2432; NR 30 TC 161 Z9 167 U1 3 U2 32 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 6 PY 2001 VL 413 IS 6851 BP 57 EP 60 DI 10.1038/35092536 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 469EG UT WOS:000170801200036 PM 11544523 ER PT J AU Ferruzzi, MG Nguyen, ML Sander, LC Rock, CL Schwartz, SJ AF Ferruzzi, MG Nguyen, ML Sander, LC Rock, CL Schwartz, SJ TI Analysis of lycopene geometrical isomers in biological microsamples by liquid chromatography with coulometric array detection SO JOURNAL OF CHROMATOGRAPHY B LA English DT Article DE geometrical isomers; coulometric array detection; lycopene ID BETA-CAROTENE; HUMAN PLASMA; ALPHA-TOCOPHEROL; CERVICAL TISSUE; TRANS-LYCOPENE; RETINOL; CANCER; SEPARATION; PROSTATE AB Methods of analysis for determining low quantities of lycopene cis-trans isomers in biological tissues are needed. Development of two liquid chromatography (LC) methods based on the polymeric C-30 stationary phase equipped with coulometric electrochemical array detection (ED) is described. Separation of 13 lycopene isomers including prolycopene, (a novel tetra-cis-lycopene found in Tangerine tomatoes) was accomplished with both isocratic and gradient methods using different proportions of methanol, methyl tert.-butyl ether, water and 1 M ammonium acetate buffer. Carotenoids were detected at potential settings between 200 and 620 mV. Differences in generated current-voltage curves aided in tentative identification of trans carotenoid species and select cis isomers of lycopene. These methods were successfully applied in the analysis of small quantities of plasma, buccal mucosal cells, prostate and cervical tissues. Limits of detection for trans-lycopene by ED were found to be 50 fmol representing a 10- to 100-fold increase over conventional UV-Vis absorbance methods. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Ohio State Univ, Dept Food Sci & Technol, Columbus, OH 43210 USA. NIST, 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, 2001 Fyffe Court, Columbus, OH 43210 USA. OI Schwartz, Steven/0000-0002-1427-5780 NR 23 TC 45 Z9 54 U1 1 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4347 J9 J CHROMATOGR B JI J. Chromatogr. B PD SEP 5 PY 2001 VL 760 IS 2 BP 289 EP 299 DI 10.1016/S0378-4347(01)00288-2 PG 11 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 463GV UT WOS:000170469500012 PM 11530988 ER PT J AU Johnson, TJ Waddell, EA Kramer, GW Locascio, LE AF Johnson, TJ Waddell, EA Kramer, GW Locascio, LE TI Chemical mapping of hot-embossed and UV-laser- ablated microchannels in poly(methyl methacrylate) using carboxylate specific fluorescent probes SO APPLIED SURFACE SCIENCE LA English DT Article DE carboxylate surface group; fluorescein probe; hot imprinting; microchannel; poly(methyl methacrylate); UV laser ablation ID INTEGRATED CAPILLARY ELECTROPHORESIS; GLASS CHIPS; PCR AMPLIFICATION; SAMPLE INJECTION; POLYMER SURFACES; DNA ANALYSIS; 248 NM; ULTRAVIOLET; MICROCHIP; DEVICES AB The physical morphology and chemical functionality of fluid microchannels formed in poly(methyl methacrylate) (PMMA) substrates were studied to increase the fundamental understanding of polymer microchannel surface properties for 'lab-on-a-chip' devices. Microchannels were formed by a hot-imprint method using a silicon template or by a laser ablation process (248 nm KrF laser) operating at low to moderate fluence levels (up to 1180 mJ/cm(2)). The carboxylate groups, which are responsible for the surface charges, were fluorescently labeled by reaction with an ethyl-dimethylaminopropyl-carbodiimide hydrochloride/amino-fluorescein solution. Fluorescence microscopy was then used to locate and measure qualitatively the charge present on the microchannel walls. Results suggest that surface charges are localized on the corners of trapezoidal channels formed by the hot-imprint method and that the amount of charge present is significantly less compared to laser-ablated microchannels where charges appear to be distributed uniformly. For substrates irradiated at fluences above the laser ablation threshold, it was found that one pass of the laser produced a surface with greater charge than channels made with multiple passes, that ablation under nitrogen resulted in more charge than ablation under oxygen, and that non-sonicated substrates had more charge than samples that were sonicated after ablation. Trends in the data for sonicated samples are explained through scanning electron microscopy images showing etch depth and UV-laser penetration to depths below the surface of the formed microchannel. Finally, we have determined that the surface charge on the substrate can be modified by using the laser at fluence levels lower than those required to ablate the substrate. (C) 2001 Elsevier Science B.V. All rights reserved. C1 NIST, Ctr Analyt Chem, Gaithersburg, MD 20899 USA. RP Johnson, TJ (reprint author), NIST, Ctr Analyt Chem, 100 Bur Dr,Stop 8394, Gaithersburg, MD 20899 USA. NR 43 TC 35 Z9 35 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD SEP 3 PY 2001 VL 181 IS 1-2 BP 149 EP 159 DI 10.1016/S0169-4332(01)00384-1 PG 11 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 473TC UT WOS:000171063300017 ER PT J AU Soininen, JA Hamalainen, K Caliebe, WA Kao, CC Shirley, EL AF Soininen, JA Hamalainen, K Caliebe, WA Kao, CC Shirley, EL TI Core-hole-electron interaction in x-ray Raman scattering SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID AB-INITIO CALCULATION; DYNAMIC STRUCTURE FACTOR; ENERGY-LOSS SCATTERING; EXCHANGE-CORRELATION; DIELECTRIC MATRICES; OPTICAL-ABSORPTION; DIAMOND; SEMICONDUCTORS; EXCITON; INSULATORS AB This work applies a recently developed first-principles scheme for calculating core excited states in solids to non-resonant inelastic x-ray scattering. The model explicitly includes the interaction between the excited electron and the core hole. The calculated results are compared with recent experimental results on inelastic x-ray scattering from K shells of Li, Be and C in lithium fluoride, beryllium oxide and diamond, respectively. The overall agreement between experimental and theoretical spectra is found to be good in all cases, even for the near-edge structure. C1 Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland. RI Hamalainen, Keijo/A-3986-2010 OI Hamalainen, Keijo/0000-0002-9234-9810 NR 41 TC 35 Z9 35 U1 1 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 3 PY 2001 VL 13 IS 35 BP 8039 EP 8047 DI 10.1088/0953-8984/13/35/311 PG 9 WC Physics, Condensed Matter SC Physics GA 479QV UT WOS:000171415800016 ER PT J AU Choi, SM Lynn, JW Lopez, D Gammel, PL Canfield, PC Bud'ko, SL AF Choi, SM Lynn, JW Lopez, D Gammel, PL Canfield, PC Bud'ko, SL TI Direct observation of spontaneous weak ferromagnetism in the superconductor ErNi2B2C SO PHYSICAL REVIEW LETTERS LA English DT Article ID SINGLE-CRYSTAL ERNI2B2C; MAGNETIC ORDER; SPIN; COEXISTENCE; TRANSITION; STATE; SCATTERING; ERRH4B4; PHASE AB Neutron measurements show that superconducting ErNi2B2C (T-c = 11 K) develops anti ferromagnetic spin density wave magnetic order (T-N = 6 K), which squares up with decreasing temperature yielding a series of higher-order magnetic Bragg peaks with odd harmonies. Below T-WFM = 2.3 K where magnetization indicates a net moment develops, even-order Bragg peaks develop which low field (similar to3 Oe) polarized beam measurements show are magnetic in origin. The data directly demonstrate the existence of a net magnetization with a periodicity of 20a, confirming the microscopic coexistence of spontaneous weak ferromagnetism with superconductivity. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Choi, SM (reprint author), Korea Adv Inst Sci & Technol, Dept Nucl Engn, Taejon 305701, South Korea. RI Canfield, Paul/H-2698-2014 NR 32 TC 45 Z9 46 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2001 VL 87 IS 10 BP art. no. EP 107001 DI 10.1103/PhysRevLett.87.107001 PG 4 WC Physics, Multidisciplinary SC Physics GA 470ZA UT WOS:000170901300033 PM 11531497 ER PT J AU Gallagher, A AF Gallagher, A TI Some physics and chemistry of hot-wire deposition SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 1st International Conference on Cat-CVD (Hot Wire CVD) Process CY NOV 14-17, 2000 CL KANAZAWA, JAPAN DE physics; chemistry; hot-wire deposition ID HYDROGENATED AMORPHOUS-SILICON; SILANE PYROLYSIS; SURFACE AB Although hot-wire chemical vapor deposition (HWCVD) involves far fewer species than plasma enhanced CVD, 'some physics and chemistry' has been used in the title because less is known than unknown regarding the hot-wire deposition processes, even for pure silane. I will concentrate on intrinsic a-Si:H deposition from SiH4 or SiH4/H-2 vapors, since this is the simplest and most studied system, and it has considerable practical importance. I will start with the reactions on the hot wire, a metal filament, then discuss the radical-vapor reactions and finally, the surface reactions that produce the film and its properties. This is not a review, and I will not attempt to cover all work that has been done to elucidate these processes. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Gallagher, A (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 6 TC 46 Z9 49 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 3 PY 2001 VL 395 IS 1-2 BP 25 EP 28 DI 10.1016/S0040-6090(01)01201-9 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 483GJ UT WOS:000171625000005 ER PT J AU Toledano, JC Berry, RS Brown, PJ Glazer, AM Metselaar, R Pandey, D Perez-Mato, JM Roth, RS Abrahams, SC AF Toledano, JC Berry, RS Brown, PJ Glazer, AM Metselaar, R Pandey, D Perez-Mato, JM Roth, RS Abrahams, SC TI Nomenclature of magnetic, incommensurate, composition-changed morphotropic, polytype, transient-structural and quasicrystalline phases undergoing phase transitions. II. Report of an IUCr Working Group on Phase Transition Nomenclature SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID NEUTRON-DIFFRACTION; INTERNATIONAL-UNION; IONIC-CONDUCTIVITY; CRYSTALLOGRAPHY; TRANSFORMATION; EUAS3; K3NDSI6O15-CENTER-DOT-XH(2)O; EU(AS1-XPX)3; SYMMETRY; 2H-TASE2 AB A general nomenclature applicable to the phases that form in any sequence of transitions in the solid state has been recommended by an IUCr Working Group [Acta Cryst. (1998). A54, 1028-1033]. The six-field notation of the first Report, hereafter I, was applied to the case of structural phase transitions, i.e. to transformations resulting from temperature and/or pressure changes between two crystalline (strictly periodic) phases involving modifications to the atomic arrangement. Extensive examples that illustrate the recommendations were provided. This second Report considers, within the framework of a similar six-field notation, the more complex nomenclature of transitions involving magnetic phases, incommensurate phases and transitions that occur as a function of composition change. Extension of the nomenclature to the case of phases with less clearly established relevance to standard schemes of transition in equilibrium systems, namely polytype phases, radiation-induced and other transient phases, quasicrystalline phases and their transitions is recommended more tentatively. A uniform notation for the translational periodicity, propagation vector or wavevector for magnetic and/or incommensurate substances is specified. The notation adopted for incommensurate phases, relying partly on the existence of an average structure, is also consistent with that for commensurate phases in a sequence. The sixth field of the nomenclature is used to emphasize the special features of polytypes and transient phases. As in I, illustrative examples are provided for each category of phase sequence. C1 So Oregon Univ, Dept Phys, Ashland, OR 97520 USA. Ecole Polytech, Solides Irradies Lab, F-91128 Palaiseau, France. Ecole Polytech, Dept Phys, F-91128 Palaiseau, France. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. Eindhoven Univ Technol, Lab Solid State & Mat Chem, NL-5600 MB Eindhoven, Netherlands. Banaras Hindu Univ, Sch Mat Sci & Technol, Varanasi 221005, Uttar Pradesh, India. Univ Basque Country, Dept Fis Mat Condensada, E-48080 Bilbao, Spain. Natl Inst Stand & Technol, Washington, DC 20234 USA. RP Abrahams, SC (reprint author), So Oregon Univ, Dept Phys, Ashland, OR 97520 USA. EM sca@mind.net RI Perez-Mato, J. Manuel/G-8669-2015 OI Perez-Mato, J. Manuel/0000-0001-5047-0578 NR 53 TC 14 Z9 14 U1 2 U2 7 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD SEP PY 2001 VL 57 BP 614 EP 626 DI 10.1107/S0108767301006821 PN 5 PG 13 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 468UT UT WOS:000170777100015 PM 11526310 ER PT J AU Bryant, RA Driscoll, JF AF Bryant, RA Driscoll, JF TI Structure of supersonic flames imaged using OH/acetone planar laser-induced fluorescence SO AIAA JOURNAL LA English DT Article ID JET FLAMES; SHEAR-LAYER; ACETONE; TEMPERATURE; COMBUSTION; PRESSURE; COMPRESSIBILITY; DEPENDENCES; DIFFUSION; LIMITS AB The general structure of a supersonic flame was identified by obtaining images of the laser-induced fluorescence from hydroxyl (OH) radicals and from acetone, which was used to mark the hydrogen fuel in the low-temperature region upstream of the lifted flame base. Results are compared to the numerical simulations of Roy and Edwards (Roy, C. J., and Edwards, J. R., "Numerical Simulation of a Three-Dimensional Flame/Shock Wave Interaction," AIAA Journal, Vol. 38, No. 5, 2000, pp. 745-754). The flame properties are significantly affected by the liftoff of the flame base and by the intense fuel/air mixing in the liftoff region, both of which are driven by the supersonic coflow. The lifted supersonic flame has the following two features that are associated with premixed flames: 1) there is significant mixing of air into the fuel stream upstream of the flame base (as evidenced by the rapid decrease in the fuel marker intensity in the low temperature liftoff region); 2) OH radicals (but not fuel) exist on the centerline everywhere downstream of the flame base. This condition is significantly different from the conditions within attached jet flames, which typically contain fuel near the centerline from the flame base to the flame tip. The results indicate that precautions should be taken in the attempt to model lifted flames, so that the premixed nature of the flame base is simulated correctly. C1 Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. RP Bryant, RA (reprint author), NIST, Mail Stop 8653,100 Bur Dr, Gaithersburg, MD 20899 USA. NR 33 TC 6 Z9 6 U1 0 U2 2 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 SEP PY 2001 VL 39 IS 9 BP 1735 EP 1741 DI 10.2514/2.1503 PG 7 WC Engineering, Aerospace SC Engineering GA 468JZ UT WOS:000170755500011 ER PT J AU Ross, D Gaitan, M Locascio, LE AF Ross, D Gaitan, M Locascio, LE TI Temperature measurement in microfluidic systems using a temperature-dependent fluorescent dye SO ANALYTICAL CHEMISTRY LA English DT Article ID LASER-INDUCED FLUORESCENCE; CAPILLARY-ELECTROPHORESIS; PCR AMPLIFICATION; HEAT-TRANSFER; THERMOMETRY; MICROCHIP; CHROMATOGRAPHY; FABRICATION; PERFORMANCE; SEPARATION AB A technique is described for the measurement of fluid temperatures in microfluidic systems based on temperature-dependent fluorescence. The technique is easy to implement with a standard fluorescence microscope and CCD camera. In addition, the method can be used to measure fluid temperatures with micrometer spatial resolution and millisecond time resolution. The efficacy of the method is demonstrated by measuring temperature distributions resulting from Joule heating in a variety of microfluidic circuits that are electrokinetically pumped. With the equipment used for these measurements, fluid temperatures ranging from room temperature to 90 degreesC were measured with a precision ranging from 0.03 to 3.5 degreesC-dependent on the amount of signal averaging done. The spatial and temporal resolutions achieved were 1 mum and 33 ms, respectively. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Proc Measurements Div, Gaithersburg, MD 20899 USA. RP Locascio, LE (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. EM Laurie.Locascio@nist.gov NR 36 TC 359 Z9 363 U1 6 U2 100 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 SEP 1 PY 2001 VL 73 IS 17 BP 4117 EP 4123 DI 10.1021/ac010370l PG 7 WC Chemistry, Analytical SC Chemistry GA 470FG UT WOS:000170859300021 PM 11569800 ER PT J AU Shirley, EL Terraciano, ML AF Shirley, EL Terraciano, ML TI Two innovations in diffraction calculations for cylindrically symmetrical systems SO APPLIED OPTICS LA English DT Article ID EXTENDED SOURCES; RADIOMETRY; APERTURES AB Two mathematical innovations are presented that relate to calculating propagation of radiation through cylindrically symmetrical systems using Kirchhoff diffraction theory. The first innovation leads to an efficient means of computing Lommel functions of two arguments (u and v), typically denoted by U-n(u, v) and V-n(u, v). This can accelerate computations involving Fresnel diffraction by circular apertures or lenses. The second innovation facilitates calculations of Kirchhoff diffraction integrals without recourse to the Fresnel approximation, yet with greatly improved efficiency like that characteristic of the latter approximation. (C) 2001 Optical Society of America. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RP Shirley, EL (reprint author), Natl Inst Stand & Technol, Opt Technol Div, 100 Bur Dr,Stop 8441, Gaithersburg, MD 20899 USA. EM eric.shirley@nist.gov NR 17 TC 12 Z9 12 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 2001 VL 40 IS 25 BP 4463 EP 4472 DI 10.1364/AO.40.004463 PG 10 WC Optics SC Optics GA 467NT UT WOS:000170711200003 PM 18360485 ER PT J AU Hockel, H Lauters, M Jackson, M Moraes, JCS Allen, MD Evenson, KM AF Hockel, H Lauters, M Jackson, M Moraes, JCS Allen, MD Evenson, KM TI Laser frequency measurements and spectroscopic assignments of optically pumped (CH3OH)-C-13 SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID FAR-INFRARED LASER; FIR LASER; LINES; METHANOL; PREDICTIONS; EMISSION; SPECTRUM AB A three-laser heterodyne system was used to measure the frequencies of twelve optically pumped laser emissions far-infrared (FIR) region. These emis-from (CH3OH)-C-13 in the far sions, ranging from 54 to 142 mum, are reported with fractional uncertainties up to +/-2 x 10(-7) along with their polarization relative to the CO2 pump. Using the 9P32 and 10R14 CO2 lines, complete spectroscopic assignments for two laser systems were confirmed. C1 Univ Wisconsin, Dept Phys, La Crosse, WI 54601 USA. UNESP, Dept Quim & Fis, BR-15385000 Ilha Solteira, SP, Brazil. Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Jackson, M (reprint author), Univ Wisconsin, Dept Phys, La Crosse, WI 54601 USA. RI Moraes, Joao /C-3406-2012 NR 19 TC 7 Z9 7 U1 0 U2 4 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 SEP PY 2001 VL 73 IS 3 BP 257 EP 260 PG 4 WC Optics; Physics, Applied SC Optics; Physics GA 486LP UT WOS:000171819500013 ER PT J AU Suydam, RS Lowry, LF Frost, KJ O'Corry-Crowe, GM Pikok, D AF Suydam, RS Lowry, LF Frost, KJ O'Corry-Crowe, GM Pikok, D TI Satellite tracking of eastern Chukchi Sea beluga whales into the Arctic Ocean SO ARCTIC LA English DT Article DE beluga whale; Delphinapterus leucas; Arctic Ocean; Chukchi Sea; movements; satellite telemetry ID COD BOREOGADUS-SAIDA; DELPHINAPTERUS-LEUCAS; MOVEMENTS; ECOLOGY; ALASKA; BAY AB Beluga whales (Delphinapterus leucas) congregate in nearshore waters of the eastern Chukchi Sea, especially in Kotzebue Sound and Kasegaluk Lagoon, in June and July. Where they travel after they leave this area was unknown before this study. We live-captured five belugas in Kasegaluk Lagoon and attached satellite-linked depth recorders to them. The belugas, caught between 26 June and 1 July 1998, were all males, ranging in length from 398 to 440 cm. A 310 cm gray beluga accompanied the smallest male. Two tags transmitted for only about two weeks, during which time one animal remained in the vicinity of Icy Cape, 80 km north of the capture site, and the other traveled to Point Barrow, about 300 km north. The other three tags operated for 60-104 days, and those belugas traveled more than 2000 km, reaching 80 degreesN and 133 degreesW, almost 1100 km north of the Alaska coast. This journey required them to move through 700 km of more than 90% ice cover. Two of the whales then moved southward into the Beaufort Sea north and east of Point Barrow. Two whales later moved to an area north of the Mackenzie River delta, where they spent 2-3 weeks before once again heading southwest towards Barrow. C1 N Slope Borough Dept Wildlife Management, Barrow, AK 99723 USA. Alaska Dept Fish & Game, Fairbanks, AK 99701 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Suydam, RS (reprint author), N Slope Borough Dept Wildlife Management, POB 69, Barrow, AK 99723 USA. NR 24 TC 49 Z9 52 U1 1 U2 14 PU ARCTIC INST N AMER PI CALGARY PA UNIV OF CALGARY 2500 UNIVERSITY DRIVE NW 11TH FLOOR LIBRARY TOWER, CALGARY, ALBERTA T2N 1N4, CANADA SN 0004-0843 J9 ARCTIC JI Arctic PD SEP PY 2001 VL 54 IS 3 BP 237 EP 243 PG 7 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 481QZ UT WOS:000171532300004 ER PT J AU Heide-Jorgensen, MP Hammeken, N Dietz, R Orr, J Richard, PR AF Heide-Jorgensen, MP Hammeken, N Dietz, R Orr, J Richard, PR TI Surfacing times and dive rates for narwhals (Monodon monoceros) and belugas (Delphinapterus leucas) SO ARCTIC LA English DT Article DE Baffin Bay; behaviour; belugas; dive rate; narwhals; surfacing time ID DIVING BEHAVIOR; BAFFIN-BAY; GREENLAND; WHALES; TRANSMITTERS; MOVEMENTS; ISLAND; WATERS; DIET AB Time spent at and near the sea surface was measured for 25 narwhals, Monodon monoceros, and 39 belugas or white whales, Delphinapterus leucas, in West Greenland and Canada from 1993 through 1999, using satellite-linked data recorders. Narwhals spent less time at the surface than belugas did, and the surfacing time of belugas also varied between localities. No clear differences in surfacing time were associated with the time of day, but belugas tended to make more dives during the night than during the day. Despite large variability in surfacing behaviour among individual whales, time spent at the surface by both species declined from August through November. The few data collected from narwhals from November to February indicate that surfacing times remained low during this period although more than 25% of each 6 h period was spent at the surface. Whales made between 2 and 20 dives per hour. and narwhals made significantly fewer dives than did belugas, for which number of dives varied with locality. The number of dives deeper than 8 in declined substantially during the autumn for belugas and narwhals that were moving offshore. When travelling, the whales apparently made fewer dives than at other times. C1 Greenland Inst Nat Resources, DK-3900 Nuuk, Greenland. Natl Environm Res Inst, Dept Arctic Environm, DK-4000 Roskilde, Denmark. Fisheries & Oceans Canada, Arctic Res Div, Cent & Arctic Reg, Winnipeg, MB R3T 2N6, Canada. RP Heide-Jorgensen, MP (reprint author), Natl Marine Fisheries Serv, Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. RI Dietz, Rune/L-4640-2013; Dietz, Rune/F-9154-2015 NR 17 TC 16 Z9 18 U1 2 U2 18 PU ARCTIC INST N AMER PI CALGARY PA UNIV OF CALGARY 2500 UNIVERSITY DRIVE NW 11TH FLOOR LIBRARY TOWER, CALGARY, ALBERTA T2N 1N4, CANADA SN 0004-0843 J9 ARCTIC JI Arctic PD SEP PY 2001 VL 54 IS 3 BP 284 EP 298 PG 15 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 481QZ UT WOS:000171532300008 ER PT J AU Streets, DG Gupta, S Waldhoff, ST Wang, MQ Bond, TC Bo, YY AF Streets, DG Gupta, S Waldhoff, ST Wang, MQ Bond, TC Bo, YY TI Black carbon emissions in China SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE black carbons; China; biofuels; emission factors; coal combustion ID PARTICULATE ELEMENTAL CARBON; COAL COMBUSTION; TRACE-ELEMENTS; LIGHT-DUTY; FLY-ASH; VEHICLES; PARTICLES; CLIMATE; PLANT; ASIA AB Black carbon (BC) is an important aerosol species because of its global and regional influence on radiative forcing and its local effects on the environment and human health. We have estimated the emissions of BC in China, where roughly one-fourth of global anthropogenic emissions is believed to originate. China's high rates of usage of coal and biofuels are primarily responsible for high BC emissions. This paper pays particular attention to the application of appropriate emission factors for China and the attenuation of these emissions where control devices are used. Nevertheless, because of the high degree of uncertainty associated with BC emission factors, we provide ranges of uncertainty for our emission estimates, which are approximately a factor of eight. In our central case, we calculate that BC emissions in China in 1995 were 1342 Gg, about 83% being generated by the residential combustion of coal and biofuels, We estimate that BC emissions could fall to 1224 Gg by 2020. This 9% decrease in BC emissions can be contrasted with the expected increase of 50% in energy use; the reduction will be obtained because of a transition to more advanced technology, including greater use of coal briquettes in place of raw coal in cities and towns. The increased use of diesel vehicles in the future will result in a greater share of the transport sector in total BC emissions. Spatially, BC emissions are predominantly distributed in an east-west swath across China's heartland, where the rural use of coal and biofuels for cooking and heating is widespread. This is in contrast Lo the emissions of most other anthropogenically derived air pollutants. which are closely tied to population and industrial centers. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Beijing Municipal Inst Labor Protect, Dept Air Pollut Control, Beijing 100054, Peoples R China. RP Streets, DG (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bond, Tami/A-1317-2013; OI Bond, Tami/0000-0001-5968-8928; Streets, David/0000-0002-0223-1350 NR 76 TC 281 Z9 344 U1 14 U2 117 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 SEP PY 2001 VL 35 IS 25 BP 4281 EP 4296 DI 10.1016/S1352-2310(01)00179-0 PG 16 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 468GF UT WOS:000170749200007 ER PT J AU Draxler, RR Gillette, DA Kirkpatrick, JS Heller, J AF Draxler, RR Gillette, DA Kirkpatrick, JS Heller, J TI Estimating PM10 air concentrations from dust storms in Iraq, Kuwait and Saudi Arabia SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE long-range transport; Southwest Asia; resuspension; aeolian movement; HYSPLIT ID THRESHOLD; PARTICLES; WIND AB A model for the emission of PM10 dust has been constructed using the concept of a threshold friction velocity which is dependent on surface roughness. Surface roughness in turn was correlated with geomorphology or soil properties for Kuwait, Iraq, part of Syria, Saudi Arabia, the United Arab Emirates and Oman. The PM10 emission algorithm was incorporated into a Lagrangian transport and dispersion model. PM10 air concentrations were computed from August 1990 through August 1991. The model predicted about the right number of dust events over Kuwait (events occur 18% of the time). The model results agreed quantitatively with measurements at four locations in Saudi Arabia and one in Kuwait for one major dust event (> 1000 mug/m(3)). However, for smaller scale dust events (200-1000 mug/m(3)), especially at the coastal sampling locations, the model substantially over-predicted the air concentrations. Part of the over-prediction was attributed to the entrainment of dust-free air by the sea breeze, a flow feature not represented by the large-scale gridded meteorological data fields used in the model computation. Another part of the over-prediction was the model's strong sensitivity to threshold friction velocity and the surface soil texture coefficient (the soil emission factor), and the difficulty in accurately representing these parameters in the model. A comparison of the model predicted PM to spatial pattern with the TOMS satellite aerosol index (Al) yielded a spatial pattern covering a major portion of Saudi Arabia that was quite similar to the observed Al pattern. Published by Elsevier Science Ltd. C1 NOAA, Air Resources Lab, RARL, Silver Spring, MD 20910 USA. NOAA, Atmospher Sci Modeling Div MD81, Res Triangle Pk, NC 27711 USA. USA, Ctr Hlth Promot & Prevent Med, Aberdeen Proving Ground, MD 21010 USA. RP NOAA, Air Resources Lab, RARL, 1315 East West Highway, Silver Spring, MD 20910 USA. EM roland.draxler@noaa.gov NR 32 TC 86 Z9 87 U1 2 U2 21 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 EI 1873-2844 J9 ATMOS ENVIRON JI Atmos. Environ. PD SEP PY 2001 VL 35 IS 25 BP 4315 EP 4330 DI 10.1016/S1352-2310(01)00159-5 PG 16 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 468GF UT WOS:000170749200010 ER PT J AU Fairey, ER Dechraoui, MYB Sheets, MF Ramsdell, JS AF Fairey, ER Dechraoui, MYB Sheets, MF Ramsdell, JS TI Modification of the cell based assay for brevetoxins using human cardiac voltage dependent sodium channels expressed in HEK-293 cells SO BIOSENSORS & BIOELECTRONICS LA English DT Article DE sodium channel; heart; brevetoxin; fos; cAMP response element; serum response element ID HIPPOCAMPAL-NEURONS; SHELLFISH POISON; GENE-EXPRESSION; REPORTER GENE; CIGUATOXINS; CALCIUM; FOS; TRANSCRIPTION; CREB; CALMODULIN AB Assays using living cells provide an effective means to generate activity measurements of toxins, especially in situations where the toxins are part of a complex mixture or in an unfamiliar form such as natural or synthetic derivatives or bioactive metabolites. An important step in the refinement of cell ba icd assays is to simplify the cellular reactions needed or required to generate the functional response of interest. Advances in the engineering of functional responses in cells provide a means to direct the response to given toxins. In this report, we describe the homogeneous high level expression of the initial target for brevetoxin, the voltage dependent sodium channel in human embryonic kidney cells (HEK-293). HEK cells stably transfected with a 6.208 kb cDNA of human heart voltage-dependent Na+ channel (hH1a) were examined as an alternative to mouse neuroblastoma cells (MA). The HEK-hH1a cells showed a reduced dependence on cofactors, increased sensitivity to brevetoxin and a useful means to assure absolute selectivity to the sodium channel. We next assessed the assay in a reporter gene format. Expression of a panel of minimal response elements as well as the c-fos promoter failed to provide a response to brevetoxin, indicating that the HEK cells lack a necessary intermediate signaling component. The expression of voltage dependent sodium channels in HEK cells is anticipated to provide enhanced performance for cell-based detection of toxins for drug and natural product discovery, biomonitoring and environmental monitoring. (C) 2001 Published by Elsevier Science B.V. C1 Natl Ocean Serv, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, NOAA, Charleston, SC 29412 USA. Univ Utah, Nora Eccles Harrison CVRTI, Salt Lake City, UT 84112 USA. Univ Utah, Div Cardiol, Salt Lake City, UT 84112 USA. RP Ramsdell, JS (reprint author), Natl Ocean Serv, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, NOAA, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 39 TC 17 Z9 21 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0956-5663 J9 BIOSENS BIOELECTRON JI Biosens. Bioelectron. PD SEP PY 2001 VL 16 IS 7-8 BP 579 EP 586 DI 10.1016/S0956-5663(01)00172-5 PG 8 WC Biophysics; Biotechnology & Applied Microbiology; Chemistry, Analytical; Electrochemistry; Nanoscience & Nanotechnology SC Biophysics; Biotechnology & Applied Microbiology; Chemistry; Electrochemistry; Science & Technology - Other Topics GA 476ZD UT WOS:000171257900018 PM 11544052 ER PT J AU Yozell, SJ AF Yozell, SJ TI Text of the keynote presentation to the International Conference on Scientific Aspects of Coral Reef Assessment, Monitoring, and Restoration - April 16, Ft. Lauderdale, Florida SO BULLETIN OF MARINE SCIENCE LA English DT Editorial Material C1 NOAA, US Dept Commerce, Silver Spring, MD 20910 USA. RP Yozell, SJ (reprint author), Battelle Mem Inst, Program Dev, Columbus, OH 43201 USA. NR 0 TC 0 Z9 1 U1 0 U2 3 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 SEP PY 2001 VL 69 IS 2 BP 295 EP 303 PG 9 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 500CU UT WOS:000172609000002 ER PT J AU Jaap, WC Hudson, JH AF Jaap, WC Hudson, JH TI Coral reef restoration following anthropogenic disturbances SO BULLETIN OF MARINE SCIENCE LA English DT Editorial Material C1 Florida Marine Res Inst, St Petersburg, FL 33701 USA. Florida Keys Natl Marine Sanctuary, Key Largo, FL 33037 USA. RP Jaap, WC (reprint author), Florida Marine Res Inst, 100 8th Ave SE, St Petersburg, FL 33701 USA. NR 0 TC 1 Z9 1 U1 2 U2 14 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 SEP PY 2001 VL 69 IS 2 BP 333 EP 333 PG 1 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 500CU UT WOS:000172609000009 ER PT J AU Miller, MW Barimo, J AF Miller, MW Barimo, J TI Assessment of juvenile coral populations at two reef restoration sites in the Florida Keys National Marine Sanctuary: Indicators of success? SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT International Conference on Scientific Aspects of Coral Reef Assessment Monitoring and Restoration CY APR 14-16, 1999 CL FT LAUDERDALE, FLORIDA ID SCLERACTINIAN CORALS; RECRUITMENT; ABUNDANCE; COMMUNITY; PATTERNS AB Two major ship groundings in 1989 damaged reef habitats in the northern Florida Keys National Marine Sanctuary, the MV ALEC OWEN MAITLAND and the MV ELPIs. Both sites underwent structural restoration in 1995. involving the emplacement of exogenous structures to stabilize loose rubble and fill in lost reef framework. These two projects of the same age and similar location, but differing in depth and structure design, provide an opportunity to evaluate restoration success in terms of the re-establishment of coral populations via in situ recruitment. In fact, coral assemblages differ markedly in density, size distribution, and diversity between the two sites. Within the MAITLAND site, coral recruitment is positively associated with rough limerocks embedded in the concrete restoration structure, but the coral assemblage is dominated by a single species, Porites astreoides. At the ELPIS site.. the juvenile coral assemblage has substantial representation by four taxa and has estimated juvenile density 50% greater than MAITLAND. These differences are associated with differences in the benthic algal assemblages at the two sites. It is hypothesized that differences in algal assemblage may result from differing structure designs (e.g., differing material, surface texture, and,,or surface orientation) and may mediate differential coral recruitment success at the two sites. C1 NOAA Fisheries, SE Sci Ctr, Miami, FL 33149 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Biol & Fisheries, Miami, FL 33149 USA. RP Miller, MW (reprint author), NOAA Fisheries, SE Sci Ctr, 75 Virginia Beach Dr, Miami, FL 33149 USA. NR 22 TC 18 Z9 22 U1 2 U2 16 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 SEP PY 2001 VL 69 IS 2 BP 395 EP 405 PG 11 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 500CU UT WOS:000172609000014 ER PT J AU Hudson, JH Goodwin, WB AF Hudson, JH Goodwin, WB TI Assessment of vessel grounding injury to coral reef and seagrass habitats in the Florida Keys National Marine Sanctuary, Florida: Protocol and methods SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT International Conference on Scientific Aspects of Coral Reef Assessment Monitoring and Restoration CY APR 14-16, 1999 CL FT LAUDERDALE, FLORIDA C1 Florida Keys Nacl Marine Sanctuary, Key Largo, FL 33037 USA. RP Hudson, JH (reprint author), Florida Keys Nacl Marine Sanctuary, POB 1083, Key Largo, FL 33037 USA. NR 8 TC 9 Z9 9 U1 2 U2 8 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 SEP PY 2001 VL 69 IS 2 BP 509 EP 516 PG 8 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 500CU UT WOS:000172609000022 ER PT J AU Hendee, JC Mueller, E Humphrey, C Moore, T AF Hendee, JC Mueller, E Humphrey, C Moore, T TI A data-driven expert system for producing coral bleaching alerts at Sombrero Reef in the Florida Keys, USA SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT International Conference on Scientific Aspects of Coral Reef Assessment Monitoring and Restoration CY APR 14-16, 1999 CL FT LAUDERDALE, FLORIDA ID MORTALITY AB A computer expert system shell was employed to provide interpretations of near realtime acquired combinations of meteorological and oceanographic parameters from a SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) station at Sombrero Reef. When environmental conditions were conducive to coral bleaching, according to different models, 'alerts' were automatically posted to the World-Wide Web and emailed to researchers so they could verify and study bleaching events as they might happen. The models were refined using feedback from field data on bleaching recorded after alerts from the expert system. The expert system was programmed to produce alerts when sea temperatures over 30 degreesC occurred, or when temperatures of 30 degreesC occurred concomitant with low winds. Alerts were produced in June 1998 when these conditions were met, but bleaching did not occur. Reconfiguration of the system, which included a point system for three models (high sea temperature only, high sea temperature plus low winds, high sea temperature plus low winds plus low tide), resulted in the transmittal of alerts which coincided with bleaching during early August, 1998. Bleaching occurred after sea temperature reached an average of 31.5 degreesC over a period of 3 d, with excursions over 31.8 degreesC occurring over 15 times during those 3 d. High sea temperatures, low wind speeds and a very low tide occurred coincident to the time of bleaching, but it was not possible to tell if these were factors acting synergistically. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Pigeon Key Marine Res Ctr, Mote Marine Lab, Marathon, FL 33050 USA. Florida Inst Oceanog, Keys Marine Lab, Long Key, FL 33001 USA. RP Hendee, JC (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Hendee, James/E-6358-2010 OI Hendee, James/0000-0002-4799-5354 NR 28 TC 5 Z9 7 U1 0 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 SEP PY 2001 VL 69 IS 2 BP 673 EP 684 PG 12 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 500CU UT WOS:000172609000036 ER PT J AU Graham, NE Diaz, HF AF Graham, NE Diaz, HF TI Evidence for intensification of North Pacific winter cyclones since 1948 SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID WAVE CLIMATE CHANGES; EL-NINO; INTERDECADAL VARIABILITY; EXTRATROPICAL RESPONSE; ATMOSPHERIC RESPONSE; SALMON PRODUCTION; SPECTRAL-ANALYSIS; SST ANOMALIES; STORM TRACKS; SURFACE WIND AB Using NCEP-NCAR reanalysis and in situ data, evidence of important changes in the winter (December-March) cyclone climatology of the North Pacific Ocean over the past 50 years is found. The frequency and intensity of extreme cyclones has increased markedly, with associated upward trends in extreme surface winds between 25 degrees and 40 degreesN and major changes in cyclone-related circulation patterns in the Gulf of Alaska. Related increases in extreme wave heights are inferred from wave measurements and wave-model hindcast results. The more vigorous cyclone activity has apparently resulted from increasing upper-tropospheric winds and vertical wind shear over the central North Pacific. Such changes, which create an environment more favorable for cyclone formation and intensification, may be related to the observed modulation of El Nino-related teleconnections at decadal and longer timescales. It is intriguing that this trend has been relatively steady rather than the sudden or stepwise shifts documented for other aspects of North Pacific climate change. Increasing sea surface temperatures in the western tropical Pacific are suggested as a plausible cause of the observed changes, though other underlying mechanisms may also contribute. C1 HRC, San Diego, CA 92130 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. NOAA, Climate Diagnost Ctr, Boulder, CO 80303 USA. RP Graham, NE (reprint author), HRC, 12780 High Bluff Dr, San Diego, CA 92130 USA. NR 89 TC 152 Z9 161 U1 1 U2 13 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 SEP PY 2001 VL 82 IS 9 BP 1869 EP 1893 DI 10.1175/1520-0477(2001)082<1869:EFIONP>2.3.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 468HL UT WOS:000170752000002 ER PT J AU Aberson, SD AF Aberson, SD TI The ensemble of tropical cyclone track forecasting models in the north Atlantic basin (1976-2000) SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID PREDICTION; IMPROVEMENTS; SYSTEM AB The suite of tropical cyclone track forecast models in the Atlantic basin from the 1976 to 2000 hurricane seasons are treated as a forecast ensemble. The 12-h ensemble mean forecast, adjusted for forecast difficulty, has improved at a rate of just under 1% per year, and the improvement rate increases to almost 2.4% per year for the 72-h forecasts. The average size of the 72-h (48-h) error in 1976 is less than the average size of the 48-h (36-h) error in 2000. The average 36-h forecast error in 2000 is comparable to the 24-h forecast error in 1976. The ensemble Currently spans the true path of the tropical cyclone in the cross-track direction more than 90% of the time and in the alongtrack direction between 60% and 90% of the time depending on the forecast lead time, The ensemble spread is unable to provide estimates of individual forecast reliability, likely making probabilistic landfall forecasts from this ensemble unreliable. The reliability of the spread in the cross-track direction suggests the possibility of limiting hurricane watch and warning regions depending upon the ensemble spread at landfall. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP Aberson, SD (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, 4301 Rickenbacker Causway, Miami, FL 33149 USA. RI Aberson, Sim/C-4891-2013 OI Aberson, Sim/0000-0002-3670-0100 NR 30 TC 30 Z9 32 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 SEP PY 2001 VL 82 IS 9 BP 1895 EP 1904 DI 10.1175/1520-0477(2001)082<0000:TEOTCT>2.3.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 468HL UT WOS:000170752000003 ER PT J AU Chernykh, IV Alduchov, OA Eskridge, RE AF Chernykh, IV Alduchov, OA Eskridge, RE TI Trends in low and high cloud boundaries and errors in height determination of cloud boundaries SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID UPPER-AIR OBSERVATIONS; MINIMUM TEMPERATURE; CLIMATOLOGY; MAXIMUM AB Clouds are important to climate and climate trends. To determine trends in cloud-base heights and cloud-top heights, the Comprehensive Aerological Reference Data Set (CARDS) and the method of Chernykh and Eskridge are used to diagnose cloud base, top, and amount. Trends in time series of cloud bases and tops at 795 radiosonde stations from 1964 to 1998 are presented. It was found that trends in cloud-base height and cloud-top height are seasonally dependent and a function of cloud cover amount. There was a small increase in multilayer cloudiness in all seasons. Geographical distributions of decadal changes of cloud bases and tops were spatially nonuniform and depended upon the season. To estimate the errors made in calculating the heights of cloud boundaries, an analysis was made of the response of the thermistors and hygristors. Thermistors and hygristors are linear sensors of the first order. From this it is shown that the distance between calculated inflection points (cloud boundaries) of observed and true values is exactly equal to the time constant of the sensor times the balloon speed. More accurate cloud boundaries can be determined using this finding. C1 NOAA, Natl Climat Data Ctr, Asheville, NC 28801 USA. Russian Res Inst Hydrometeorol Informat, Obninsk, Russia. RP Eskridge, RE (reprint author), NOAA, Natl Climat Data Ctr, 151 Patton Ave, Asheville, NC 28801 USA. NR 19 TC 20 Z9 22 U1 2 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 SEP PY 2001 VL 82 IS 9 BP 1941 EP 1947 DI 10.1175/1520-0477(2001)082<1941:TILAHC>2.3.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 468HL UT WOS:000170752000007 ER PT J AU Kogan, FN AF Kogan, FN TI Operational space technology for global vegetation assessment SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID HIGH-RESOLUTION RADIOMETER; UNITED-STATES; EL-NINO; METEOROLOGICAL SATELLITE; SOUTHERN OSCILLATION; INFRARED CHANNELS; AVHRR DATA; CALIBRATION; IMPACTS; WEATHER AB The main goal of global agriculture and the grain sector is to feed 6 billion people. Frequent droughts causing grain shortages, economic disturbances, famine, and losses of life limit the ability to fulfill this goal. To mitigate drought consequences requires a sound early warning system. The National Oceanic and Atmospheric Administration (NOAA) has recently developed a new numerical method of drought detection and impact assessment from the NOAA operational environmental satellites. The method was tested during the past eight years, adjusted based on users' responses, validated against conventional data in 20 countries, including all major agricultural producers, and was accepted as a tool for the diagnosis of grain production. Now, drought can be detected 4-6 weeks earlier than before, outlined more accurately, and the impact on grain reduction can be predicted long in advance of harvest, which is most vital for global food security and trade. This paper addresses all these issues and also discusses ENSO impacts on agriculture. C1 NOAA, NESDIS, Ctr Sci, Camp Springs, MD 20746 USA. RP Kogan, FN (reprint author), NOAA, NESDIS, Ctr Sci, 5200 Auth Rd, Camp Springs, MD 20746 USA. RI Kogan, Felix/F-5600-2010 OI Kogan, Felix/0000-0001-8216-900X NR 45 TC 83 Z9 94 U1 4 U2 15 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 SEP PY 2001 VL 82 IS 9 BP 1949 EP 1964 DI 10.1175/1520-0477(2001)082<1949:OSTFGV>2.3.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 468HL UT WOS:000170752000008 ER PT J AU Atlas, R Hoffman, RN Leidner, SM Sienkiewicz, J Yu, TW Bloom, SC Brin, E Ardizzone, J Terry, J Bungato, D Jusem, JC AF Atlas, R Hoffman, RN Leidner, SM Sienkiewicz, J Yu, TW Bloom, SC Brin, E Ardizzone, J Terry, J Bungato, D Jusem, JC TI The effects of marine winds from scatterometer data on weather analysis and forecasting SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID DATA ASSIMILATION SYSTEM; GLOBAL SURFACE WIND; QE-II STORM; SEASAT SCATTEROMETER; SATELLITE SCATTEROMETER; AMBIGUITY REMOVAL; EUROPEAN-CENTER; NSCAT WINDS; VARIATIONAL ASSIMILATION; VECTOR WINDS AB Satellite scatterometer observations of the ocean surface wind speed and direction improve the depiction of storms at sea. Over the ocean, scatterometer surface winds are deduced from multiple measurements of reflected radar power made from several directions. In the nominal situation, the scattering mechanism is Bragg scattering from centimeter-scale waves, which are in equilibrium with the local wind. These data are especially valuable where observations are otherwise sparse-mostly in the Southern Hemisphere extratropics and Tropics, but also on occasion in the North Atlantic and North Pacific. The history of scatterometer winds research and its application to weather analysis and forecasting is reviewed here. Two types of data impact studies have been conducted to evaluate the effect of satellite data, including satellite scatterometer data, for NWP. These are simulation experiments (or observing system simulation experiments or OSSEs) designed primarily to assess the potential impact of planned satellite observing systems, and real data impact experiments (or observing system experiments or OSEs) to evaluate the actual impact of available space-based data. Both types of experiments have been applied to the series of satellite scatterometers carried on the Seasat, European Remote Sensing-1 and -2, and the Advanced Earth Observing System-1 satellites, and the NASA Quick Scatterometer. Several trends are evident: The amount of scatterometer data has been increasing. The ability of data assimilation systems and marine forecasters to use the data has improved substantially. The ability of simulation experiments to predict the utility of new sensors has also improved significantly. C1 NASA, Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20771 USA. Atmospher & Environm Res Inc, Cambridge, MA 02139 USA. Natl Ctr Environm Predict, Washington, DC USA. Gen Sci Corp, Laurel, MD USA. RP NASA, Goddard Space Flight Ctr, Data Assimilat Off, Mail Code 910-3, Greenbelt, MD 20771 USA. EM atlas@dao.gsfc.nasa.gov RI Atlas, Robert/A-5963-2011 OI Atlas, Robert/0000-0002-0706-3560 NR 93 TC 74 Z9 83 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 EI 1520-0477 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 2001 VL 82 IS 9 BP 1965 EP 1990 DI 10.1175/1520-0477(2001)082<1965:TEOMWF>2.3.CO;2 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 468HL UT WOS:000170752000009 ER PT J AU Tesch, W Eidelman, N Roschger, P Goldenberg, F Klaushofer, K Fratzl, P AF Tesch, W Eidelman, N Roschger, P Goldenberg, F Klaushofer, K Fratzl, P TI Graded microstructure and mechanical properties of human crown dentin SO CALCIFIED TISSUE INTERNATIONAL LA English DT Article DE dentin; Fourier-transform infrared microspectroscopy; small-angle X - ray scattering; nanoindentation; quantitative backscattered electron imaging ID X-RAY-SCATTERING; SCANNING ELECTRON-MICROSCOPY; COLLAGEN CONFORMATION; MOLECULAR COMPOSITION; YIELD STRESS; HUMAN TEETH; IN-SITU; BONE; HARDNESS; MODULUS AB The mineralized tissue of intertubular dentin is a collagen-mineral composite with considerable local variations of mechanical properties. Area scans of human coronal dentin were made by complementary methods to investigate correlations between local mechanical properties and the density, size, and crystallinity of the mineral particles. Scanning images from the same specimen were collected with Fourier-transform infrared microspectroscopy in reflectance mode (FTIR-RM), small angle X-ray scattering (SAXS), quantitative backscattered electron imaging (qBEI), and Nanoindentation in an atomic force microscope. The mineral content of dentin was found to decrease and the thickness of mineral crystals to increase towards the dentin-enamel junction (DEJ). Hardness and elastic modulus both decreased towards the DEJ. In a correlation analysis, the mineral content and, even more, the thickness of mineral crystals were found as the best predictors of hardness. The dentin layer close to the DEJ corresponds to a local minimum in hardness and elastic modulus, a configuration known to be an effective obstacle for crack propagation. Hence, the observed variations of mechanical and structural properties in an area between 0 and 1.5 mm below the DEJ define crown dentin as a gradient material optimized for its mechanical function. C1 Austrian Acad Sci, Erich Schmid Inst Mat Sci, A-8700 Leoben, Austria. Austrian Acad Sci, Inst Phys Met, A-8700 Leoben, Austria. Hanusch Hosp, Ludwig Boltzmann Inst Osteol, Dept Med 4, Vienna, Austria. NIST, Paffenbarger Res Ctr, Amer Dent Assoc Hlth Fdn, Gaithersburg, MD 20899 USA. RP Fratzl, P (reprint author), Austrian Acad Sci, Erich Schmid Inst Mat Sci, Jahnstr 12, A-8700 Leoben, Austria. RI Fratzl, Peter/H-9095-2012 OI Fratzl, Peter/0000-0003-4437-7830 NR 40 TC 162 Z9 167 U1 3 U2 29 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0171-967X J9 CALCIFIED TISSUE INT JI Calcif. Tissue Int. PD SEP PY 2001 VL 69 IS 3 BP 147 EP 157 DI 10.1007/s00223-001-2012-z PG 11 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 476QB UT WOS:000171239300004 PM 11683529 ER PT J AU Silberberg, KR Laidig, TE Adams, PB Albin, D AF Silberberg, KR Laidig, TE Adams, PB Albin, D TI Analysis of maturity in Lingcod, Ophiodon elongatus SO CALIFORNIA FISH AND GAME LA English DT Article ID REPRODUCTIVE-BIOLOGY AB Lingcod, Ophiodonelongatus, maturity data from northern and central California commercial catch samples were analyzed to determine maturity patterns including length and age at 50% maturity and seasonal patterns in maturation of gonads. Female lingcod attained 50% maturity at 557 mm fork length (FL) and 3.8 years. Males attained 50% maturity at 461 mm FL and 3.2 years. Females matured over a range from 437-725 mm FL and 2-8 years of age, while males matured over a range from 390-664 mm FL and 2-7 years. The abundance of females with mature ovaries began to increase in October, prior to the spawning period, peaked in January, then declined through February. Spent females were most abundant during February and March, directly following the peak spawning period. Ripe males began to appear in September and increased in abundance through March. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz Lab, Santa Cruz, CA 95060 USA. Calif Dept Fish & Game, Ft Bragg, CA 95437 USA. RP Silberberg, KR (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz Lab, 110 Shaffer Rd, Santa Cruz, CA 95060 USA. NR 13 TC 5 Z9 5 U1 1 U2 4 PU CALIF FISH AND GAME EDITOR PI SACRAMENTO PA 1416 NINTH ST, SACRAMENTO, CA 95814 USA SN 0008-1078 J9 CALIF FISH GAME JI Calif. Fish Game PD FAL PY 2001 VL 87 IS 4 BP 139 EP 152 PG 14 WC Fisheries; Zoology SC Fisheries; Zoology GA 667VJ UT WOS:000182254500002 ER PT J AU Stevick, PT Palsboll, PJ Smith, TD Bravington, MV Hammond, PS AF Stevick, PT Palsboll, PJ Smith, TD Bravington, MV Hammond, PS TI Errors in identification using natural markings: rates, sources, and effects on capture-recapture estimates of abundance SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID HUMPBACK WHALES; TAG LOSS; PHOTOGRAPHIC IDENTIFICATION; MEGAPTERA-NOVAEANGLIAE; POPULATION; PATTERN; SEALS AB The results of a double-marking experiment using natural markings and microsatellite genetic markers to identify humpback whales (Megaptera novaeangliae) confirm that natural markings are a reliable means of identifying individuals on a large scale. Of 1410 instances of double tagging, there were 414 resightings. No false positive and 14 false negative errors were identified. The rate of error increased with decreasing photographic quality; no errors were observed among photographs of the highest quality rating, whereas an error rate of 0.125 was identified in sightings for which only part of the area used for identification was visible. There was also a weaker relationship between error rate and the distinctiveness of markings, which may result from non-independence in coding for image quality and distinctiveness. A correction is developed for the Petersen two-sample abundance estimator to account for false negative errors in identification, and a parametric bootstrap procedure for estimation of variance is also developed. In application to abundance estimates from the North Atlantic, the correction reduces the bias in estimates made using poorer quality photographs to a negligible level while maintaining comparable precision. C1 Univ St Andrews, Gatty Marine Lab, Sea Mammal Res Unit, St Andrews KY16 8LB, Fife, Scotland. Coll Atlantic, Bar Harbor, ME 04609 USA. Univ Wales, Sch Biol Sci, Bangor LL57 2UW, Gwynedd, Wales. Natl Marine Fisheries Serv, NOAA, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Stevick, PT (reprint author), Univ St Andrews, Gatty Marine Lab, Sea Mammal Res Unit, St Andrews KY16 8LB, Fife, Scotland. RI Bravington, Mark/E-8897-2010; Palsboll, Per /G-6988-2011 OI Palsboll, Per /0000-0002-4198-7599 NR 36 TC 74 Z9 79 U1 0 U2 21 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 SEP PY 2001 VL 58 IS 9 BP 1861 EP 1870 DI 10.1139/cjfas-58-9-1861 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 469JT UT WOS:000170811300017 ER PT J AU Jacobson, LD De Oliveira, JAA Barange, M Cisneros-Mata, MA Felix-Uraga, R Hunter, JR Kim, JY Matsuura, Y Niquen, M Porteiro, C Rothschild, B Sanchez, RP Serra, R Uriarte, A Wada, T AF Jacobson, LD De Oliveira, JAA Barange, M Cisneros-Mata, MA Felix-Uraga, R Hunter, JR Kim, JY Matsuura, Y Niquen, M Porteiro, C Rothschild, B Sanchez, RP Serra, R Uriarte, A Wada, T TI Surplus production, variability, and climate change in the great sardine and anchovy fisheries SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID PACIFIC SARDINE; NORTHERN ANCHOVY; SAGAX; CALIFORNIA; FLUCTUATIONS; ABUNDANCE; TRENDS; COAST AB We used fishery and survey data to calculate annual surplus production (ASP) and instantaneous surplus production rates (ISPR) for eight anchovy and nine sardine stocks. In addition, we calculated ASP per unit spawning area for six anchovy and six sardine stocks. Median ASP was highest for stocks with highest median biomass (mostly anchovies), and ASP was typically about 16% of stock biomass. ASP was often negative, more frequently for anchovies (36% of years) than for sardines (17% of years). ISPR was less variable for sardines and autocorrelated for longer-lived stocks (mostly sardines). Strong biomass increases tended to be preceded by short, abrupt increases in ISPR, and declines were pronounced when catches exceeded ASP for 5 years or more. The longest "runs" of positive and negative production were 21 and 4 years for sardine off Japan, 10 and 3 years for sardine off California, 8 and 2 years for anchovy off Peru, and 4 and 3 years for anchovy off California. ISPR is more sensitive to environmental changes than catch, biomass, or ASP and appear to be better for identifying environmentally induced regime shifts. Long time series show evidence of density-dependent effects on ASP in anchovies and sardines, but environmentally induced variation appears to dominate. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. Marine & Coastal Management, ZA-8012 Rogge Bay, South Africa. Plymouth Marine Lab, GLOBEC Int Project Off, Plymouth PL1 3DH, Devon, England. Ctr Reg Invest Pesqueras, Inst Nacl Pesca, Guaymas 85400, Sonora, Mexico. Inst Politecn Nacl, CICIMAR, La Paz 23096, BCS, Mexico. Natl Fisheries Res & Dev Inst, W Fisheries Res Inst, Jung Gu 400201, Incheon, South Korea. Univ Sao Paulo, Inst Oceanog, BR-05508 Sao Paulo, Brazil. Inst Mar Peru, Esquina Gamarra & Gen Valle, Chucuito, Callao, Peru. Ctr Oceanog Vigo, Inst Espanol Oceanog, Vigo 36280, Spain. Univ Massachusetts, Sch Marine Sci & Technol, New Bedford, MA 02744 USA. Inst Nacl Invest & Desarrollo Pesquero, RA-7600 Mar Del Plata, Argentina. Inst Fomento Pesquero, Valparaiso, Chile. Inst Tecnol Pesquero & Alimentario, San Sebastian 20008, Spain. Japan Minist Agr Forestry & Fisheries, Natl Res Inst Fisheries Sci, Kanazawa Ku, Yokohama, Kanagawa 236, Japan. RP Jacobson, LD (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02543 USA. RI Barange, Manuel/D-2689-2016 OI Barange, Manuel/0000-0002-1508-0483 NR 33 TC 59 Z9 60 U1 1 U2 18 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 SEP PY 2001 VL 58 IS 9 BP 1891 EP 1903 DI 10.1139/cjfas-58-9-1891 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 469JT UT WOS:000170811300019 ER PT J AU Yang, S Mirau, PA Pai, CS Nalamasu, O Reichmanis, E Lin, EK Lee, HJ Gidley, DW Sun, JN AF Yang, S Mirau, PA Pai, CS Nalamasu, O Reichmanis, E Lin, EK Lee, HJ Gidley, DW Sun, JN TI Molecular templating of nanoporous ultralow dielectric constant (approximate to 1.5) organosilicates by tailoring the microphase separation of triblock copolymers SO CHEMISTRY OF MATERIALS LA English DT Article ID SOLID-STATE NMR; MESOPOROUS SILICA; THIN-FILMS; POLYMERS AB Triblock polymers, poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (PEO-b-PPO-bPEO), are used as molecular templates in poly(methyl silsesquioxane) (MSQ) matrixes to fabricate nanoporous organosilicates. The triblock copolymers microphase-separate into nanometer domains as the MSQ matrix becomes increasingly hydrophobic during a curing step. Extremely small pores (2-5 nm) are generated after thermally removing the template material. These materials attain ultralow dielectric constants (k approximate to 1.5) with electrical and mechanical integrity. C1 Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. RP Yang, S (reprint author), Lucent Technol, Bell Labs, 600 Mt Ave, Murray Hill, NJ 07974 USA. RI Yang, Shu/D-9758-2011 NR 23 TC 81 Z9 81 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD SEP PY 2001 VL 13 IS 9 BP 2762 EP + DI 10.1021/cm0102786 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 474JW UT WOS:000171104200007 ER PT J AU Ordas, MC Novoa, B Faisal, M McLaughlin, S Figueras, A AF Ordas, MC Novoa, B Faisal, M McLaughlin, S Figueras, A TI Proteolytic activity of cultured Pseudoperkinsus tapetis extracellular products SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY LA English DT Article DE Pseudoperkinsus tapetis; Mesomycetozoa; DRIP; Perkinsus marinus; proteases; extracellular products; ECP; protozoan ID OYSTER CRASSOSTREA-VIRGINICA; PERKINSUS-MARINUS PROTEASES; CLAM RUDITAPES-DECUSSATUS; ALKALINE SERINE-PROTEASE; CARPET SHELL CLAM; IN-VITRO; RIBOSOMAL-RNA; MYA-ARENARIA; ATLANTICUS; PARASITE AB Several pathogenic protozoan release proteases are necessary for host invasion and initiation of infection. We have identified proteolytic activities in extracellular proteins secreted by the clam parasite Pseudoperkinsus tapetis (Mesomycetozoa) in vitro. The protein concentration of the P. tapetis extracellular products (ECP) increased only during the first week of culture. The appearance of new proteins of 10 and 157 kDa at the second week sample and of 12 kDa at the third week sample was shown by SDS-PAGE. The protease activity rapidly increased in the first 3 weeks of culture, and five clear bands of 23, 29, 60, 67 and 96 kDa with proteolytic activity were detected in the ECP on gelatin SDS-PAGE. Using inhibitors, the proteases were identified as members of the Ca2+ dependent, serine protease family. Their optimum pH was higher than pH 9.4. The protease activity of the P. tapetis ECP was different than that described for Perkinsus marinus, an oyster pathogen very similar morphologically to the clam parasite and member of the genus in which P. tapetis had been initially included. (C) 2001 Elsevier Science Inc. All rights reserved. C1 CSIC, Inst Invest Marinas, Vigo 36208, Spain. Virginia Inst Marine Sci, Coll William & Mary, Dept Environm Sci, Gloucester Point, VA 23062 USA. Natl Marine Fisheries Serv, Oxford, MD USA. RP Figueras, A (reprint author), CSIC, Inst Invest Marinas, Eduardo Cabello 6, Vigo 36208, Spain. RI Figueras, Antonio/B-5133-2015 OI Figueras, Antonio/0000-0002-0617-0030 NR 33 TC 9 Z9 10 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1096-4959 J9 COMP BIOCHEM PHYS B JI Comp. Biochem. Physiol. B-Biochem. Mol. Biol. PD SEP PY 2001 VL 130 IS 2 BP 199 EP 206 PG 8 WC Biochemistry & Molecular Biology; Zoology SC Biochemistry & Molecular Biology; Zoology GA 472ET UT WOS:000170971100011 ER PT J AU Roy, U Pramanik, N Sudarsan, R Sriram, RD Lyons, KW AF Roy, U Pramanik, N Sudarsan, R Sriram, RD Lyons, KW TI Function-to-form mapping: model, representation and applications in design synthesis SO COMPUTER-AIDED DESIGN LA English DT Article DE design synthesis; function-to-form mapping; CAD; object-oriented representation; conceptual design AB Design of a new artifact begins with incomplete knowledge about the final product and the design evolves as it progresses from the conceptual design stage to a more detailed design. In this paper, an effort has been made to give a structural framework, through a set of generic definitions, to product specification, functional representation, artifact representation, artifact behavior and tolerance representation. A design synthesis process has been proposed for evolution of a product from the product specification. The proposed design synthesis method is a mapping from the functional requirements to artifacts, with multi-stage constrained optimization during stages of design evolution. Provisions have been kept to augment and/or modify the product specification and domain knowledge during stages of development to guide the design process. The effectiveness of the proposed design process has been illustrated with a simple design example based on a sample artifact library. An overall design scheme has been presented. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Syracuse Univ, Dept Mech Aerosp Mfg Engn, Knowledge Based Engn Lab, Syracuse, NY 13244 USA. NIST, Mfg Syst Integrat Div, Engn Design Technol Grp, Gaithersburg, MD 20899 USA. RP Roy, U (reprint author), Syracuse Univ, Dept Mech Aerosp Mfg Engn, Knowledge Based Engn Lab, Syracuse, NY 13244 USA. NR 30 TC 70 Z9 87 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0010-4485 J9 COMPUT AIDED DESIGN JI Comput.-Aided Des. PD SEP PY 2001 VL 33 IS 10 BP 699 EP 719 DI 10.1016/S0010-4485(00)00100-7 PG 21 WC Computer Science, Software Engineering SC Computer Science GA 456JF UT WOS:000170078800002 ER PT J AU Rust, BW AF Rust, BW TI Fitting nature's basic functions part I: Polynomials and linear least squares SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Rust, BW (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8910, Gaithersburg, MD 20899 USA. NR 7 TC 7 Z9 7 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD SEP-OCT PY 2001 VL 3 IS 5 BP 84 EP 89 DI 10.1109/5992.895323 PG 6 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 466UW UT WOS:000170665400011 ER PT J AU Lang, JC Deslarzes, KJP Schmahl, GP AF Lang, JC Deslarzes, KJP Schmahl, GP TI The Flower Garden Banks: remarkable reefs in the NW Gulf of Mexico SO CORAL REEFS LA English DT Article C1 USDOI, Minerals Management Serv, Environm Sci Sect, New Orleans, LA 70123 USA. NOAA, Flower Garden Banks Natl Marine Sanctuary, Bryan, TX 77803 USA. RP Lang, JC (reprint author), POB 539, Ophelia, VA 22530 USA. NR 2 TC 4 Z9 6 U1 0 U2 3 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD SEP PY 2001 VL 20 IS 2 BP 126 EP 126 DI 10.1007/s003380000111 PG 1 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 477BK UT WOS:000171263100004 ER PT J AU Bruno, JF Siddon, CE Witman, JD Colin, PL Toscano, MA AF Bruno, JF Siddon, CE Witman, JD Colin, PL Toscano, MA TI El Nino related coral bleaching in Palau, Western Caroline Islands SO CORAL REEFS LA English DT Article DE coral bleaching; disturbance; El Nino; Palau; sea surface temperature ID SEA-SURFACE TEMPERATURES; GREAT-BARRIER-REEF; ULTRAVIOLET-RADIATION; SEAWATER TEMPERATURE; SCLERACTINIAN CORALS; ACANTHASTER-PLANCI; FRENCH-POLYNESIA; COMMUNITIES; MORTALITY; RECOVERY AB Mass coral bleaching is currently viewed as a major threat to the long-term health of coral reef communities. Here we quantify coral bleaching in Palau coincident with the 1997/1998 El Nino Southern Oscillation event and with local sea surface temperatures of 31 degreesC, which were 1.0-1.25 degreesC higher than long-term, satellite-derived climatological maximum monthly means for the region. We sampled nine sites, including protected lagoon and fringing reefs, vertical reef walls, and exposed barrier reefs. The percentage of living scleractinian coral tissue that was bleached was 53.4 +/- 6.2 (range: 32.3.-79.3, n=8 sites) at 3-5 m depth and 68.9 +/- 6.2 (45.7-91.7, n=6 sites) at 10-12 m and did not differ significantly between depths. The overall mean percent cover of bleached scleractinians was 18.9 +/- 1.5 (mean +/- 1 SE, n = 9 sites), while the cover of healthy corals was only 15.6 +/- 2.0. Nearly half (48%) of 946 surveyed colonies belonging to 20 scleractinian taxa were totally bleached, while 15% were partially bleached. Overall, the results indicate that the 1998 coral bleaching episode in Palau was relatively severe and widespread across depths, sites, habitats, and coral taxa. C1 Brown Univ, Dept Ecol & Evolutionary Biol, Providence, RI 02912 USA. Coral Reef Res Fdn, Koror 96940, Palau. NOAA, NESDIS, ORA, ORAD E,RA31, Silver Spring, MD 20910 USA. Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27599 USA. RP Bruno, JF (reprint author), Brown Univ, Dept Ecol & Evolutionary Biol, Providence, RI 02912 USA. RI kohki, sowa/D-2955-2011 NR 53 TC 67 Z9 72 U1 6 U2 22 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD SEP PY 2001 VL 20 IS 2 BP 127 EP 136 PG 10 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 477BK UT WOS:000171263100005 ER PT J AU McKinley, JP Zeissler, CJ Zachara, JM Serne, RJ Lindstrom, RM Schaef, HT Orr, RD AF McKinley, JP Zeissler, CJ Zachara, JM Serne, RJ Lindstrom, RM Schaef, HT Orr, RD TI Distribution and retention of Cs-137 in sediments at the Hanford Site, Washington SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SOLID/LIQUID DISTRIBUTION COEFFICIENTS; CESIUM SORPTION; CLAY-MINERALS; ILLITE; RADIOCESIUM; PREDICTION; SOILS; REVERSIBILITY; ADSORPTION; PARTICLES AB (137)Cesium and other contaminants have leaked from single-shell storage tanks (SSTs) into coarse-textured, relatively unweathered unconsolidated sediments. Contaminated sediments were retrieved from beneath a leaky SST to investigate the distribution of adsorbed Cs-137(+) across different sediment size fractions, All fractions contained mica (biotite, muscovite, vermiculatized biotite), quartz, and plagioclase along with smectite and kaolinite in the clay-size fraction. A phosphor-plate autoradiograph method was used to identify particular sediment particles responsible for retaining Cs-137(+). The Cs-bearing particles were found to be individual mica flakes or agglomerated, smectite, mica, quartz, and plagioclase. Of these, only the micaceous component was capable of sorbing Cs+ strongly. Sorbed Cs-137(+) could not be significantly removed from sediments by leaching with dithionite citrate buffer or KOH, but a fraction of the sorbed Cs-137(+) (5-22%) was desorbable with solutions containing an excess of Rb+. The small amount of Cs-137(+) that might be mobilized by migrating fluids in the future would likely sorb to nearby micaceous clasts in downgradient sediments. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP McKinley, JP (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 42 TC 65 Z9 66 U1 5 U2 28 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 SEP 1 PY 2001 VL 35 IS 17 BP 3433 EP 3441 DI 10.1021/es0018116 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 469PP UT WOS:000170824300016 PM 11563643 ER PT J AU Lee, JH Landrum, PF Field, LJ Koh, CH AF Lee, JH Landrum, PF Field, LJ Koh, CH TI Application of a Sigma polycyclic aromatic hydrocarbon model and a logistic regression model to sediment toxicity data based on a species-specific, water-only LC50 toxic unit for Hyalella azteca SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE Sigma PAH model; toxic unit; equilibrium partitioning model; logistic-regression model; Hyalella azteca ID TECHNICAL BASIS; NARCOTIC CHEMICALS; MARINE SEDIMENT; TOXICOKINETICS; FLUORANTHENE; MIXTURES; BIOAVAILABILITY; AMPHIPOD; QUALITY; CRITERIA AB Two models, a Sigma polycyclic aromatic hydrocarbon (FAH) model based on equilibrium partitioning theory and a logistic-regression model, were developed and evaluated to predict sediment-associated PAH toxicity to Hyalella azteca. A Sigma PAH model was applied to freshwater sediments. This study is the first attempt to use a Sigma PAH model based on water-only, median lethal concentration (LC50) toxic unit (TU) values for sediment-associated PAH mixtures and its application to freshwater sediments. To predict the toxicity (i.e., mortality) from contaminated sediments to H. azteca, an interstitial water TU, calculated as the ambient interstitial water concentration divided by the water-only LC50 in which the interstitial water concentrations were predicted by equilibrium partitioning theory, was used. Assuming additive toxicity for PAH, the sum of TUs was calculated to predict the total toxicity of PAH mixtures in sediments. The Sigma PAH model was developed from 10- and 14-d H. azteca water-only LC50 values. To obtain estimates of LC50 values for a wide range of PAHs, a quantitative structure-activity relationship (QSAR) model (log LC50 - log K-ow) with a constant slope was derived using the time-variable LC50 values for four PAH congeners. The logistic-regression model was derived to assess the concentration-response relationship for field sediments, which showed that 1.3 (0.6-3.9) TU were required for a 50% probability that a sediment was toxic. The logistic-regression model reflects both the effects of co-occurring contaminants (i.e., nonmeasured PAH and unknown pollutants) and the overestimation of exposure to sediment-associated PAH. An apparent site-specific bioavailability limitation of sediment-associated PAH was found for a site contaminated by creosote. At this site, no toxic samples were less than 3.9 TU. Finally, the predictability of the Sigma PAH model can be affected by species-specific responses (Hyalella vs Rhepoxynius); chemical specific (PAH vs DDT in H. azteca) biases, which are not incorporated in the equilibrium partitioning model; and the uncertainty from site-specific effects (creosote vs other sources of PAH contamination) on the bioavailability of sediment-associated PAH mixtures. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Seoul Natl Univ, Dept Oceanog, Seoul 151742, South Korea. NOAA, Off Response & Restorat, Seattle, WA 98115 USA. RP Landrum, PF (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. EM landrum@glerl.noaa.gov NR 41 TC 8 Z9 8 U1 3 U2 27 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0730-7268 EI 1552-8618 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD SEP PY 2001 VL 20 IS 9 BP 2102 EP 2113 DI 10.1897/1551-5028(2001)020<2102:AOAPAH>2.0.CO;2 PG 12 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 465RF UT WOS:000170603200034 PM 11521842 ER PT J AU Widmann, JF AF Widmann, JF TI Phase Doppler interferometry measurements in water sprays produced by residential fire sprinklers SO FIRE SAFETY JOURNAL LA English DT Article DE fire sprinklers; water sprays; drop size measurement; phase Doppler interferometry; drop velocity measurement ID PARTICLE ANALYZER AB A phase Doppler interferometry (PDI) system was used to characterize the water sprays produced by four residential fire sprinklers. Four pendent sprinklers with K-factors ranging from 7.2 x 10(-5) m(3) s(-1) kPa(-0.5) (3.0 gal min(-1) psig(-0.5)) to 1.35 x 10(-4) m(3) s(-1) kPa(-0.5) (5.6 gal min(-1) psig(-0.5)) were investigated. The measurements include characteristic size (arithmetic mean diameter, volume mean diameter, Sauter mean diameter), mean velocity (axial and radial components), and liquid volume flux. The effect of water pressure on drop size was also investigated. The mean drop size (flux-averaged volume diameter, (D(30)) over bar) was found to be proportional to p(-1/3) over the range 93 kPa less than or equal to P less than or equal to 200 kPa. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. RP Widmann, JF (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, 100 Bur Dr,Stop 8653, Gaithersburg, MD 20899 USA. EM john.widmann@nist.gov NR 37 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 SEP PY 2001 VL 36 IS 6 BP 545 EP 567 DI 10.1016/S0379-7112(01)00009-1 PG 23 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 450HH UT WOS:000169735600002 ER PT J AU Kim, J Lo, NCH AF Kim, J Lo, NCH TI Temporal variation of seasonality of egg production and the spawning biomass of Pacific anchovy, Engraulis japonicus, in the southern waters of Korea in 1983-1994 SO FISHERIES OCEANOGRAPHY LA English DT Article ID NORTHERN ANCHOVY; MORTALITY-RATES; SARDINOPS-SAGAX; FISHES; ATLANTIC; MORDAX; SIZE; COD AB Embryonic mortality, egg production and the spawning stock biomass of Pacific anchovy, Engraulis japonicus, off Southern Korea during 1983-1994, and their biological response to oceanographic features in spring and summer, were analysed. The instantaneous mortality rate (IMR) of embryonic stages decreased in spring and increased in summer, with a range of 0.33-1.23 day(-1) in spring and 0.78-1.69 day(-1) in summer. Egg production in summer was three times that during spring and production was low in the late 1980s. Mean lengths of yolk-sac larvae and adult females were greater in spring than in summer, whereas spawning fraction and spawning stock ratio (spawning biomass:adult biomass) were lower in spring than summer. Estimated mean spawning stock biomass ranged from 141 x 10(3) to 380 x 10(3) MT in spring and from 221 x 10(3) to 557 x 10(3) MT in summer. Statistically, the seasonal and long-term trends of embryonic mortality, egg production and spawning stock biomass of Pacific anchovy can be explained largely by spring warming, summer cooling and by less abundant zooplankton in the late 1980s. C1 Natl Fisheries Res & Dev Inst, Pusan 619902, South Korea. SW Fisheries Sci Ctr, La Jolla, CA 92037 USA. RP Kim, J (reprint author), Natl Fisheries Res & Dev Inst, 408-1 Shirang Ri, Pusan 619902, South Korea. NR 39 TC 19 Z9 22 U1 0 U2 5 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 SEP PY 2001 VL 10 IS 3 BP 297 EP 310 DI 10.1046/j.1365-2419.2001.00175.x PG 14 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 473DB UT WOS:000171023700006 ER PT J AU Somerton, DA Weinberg, KL AF Somerton, DA Weinberg, KL TI The affect of speed through the water on footrope contact of a survey trawl SO FISHERIES RESEARCH LA English DT Article DE trawl performance; bottom trawls; trawl catchability ID EFFICIENCY; CAPTURE; FISH AB The affect of speed through the water on the bottom contact of a trawl footrope was experimentally investigated for the poly Nor'eastern trawl, the bottom trawl used by the Alaska fisheries science center (AFSC) to conduct stock assessment surveys. Repetitive tows were made at speeds over the ground from 2.0 to 5.0 knots at 0.5 knot intervals, bracketing the 3.0 knot speed standardly used during the surveys. For each tow, speed through water was measured by placing on the trawl a self-recording oceanographic current meter and a commercially available speed through water sensor designed for use on trawls. Height of the center bobbins above the bottom was measured using a bottom contact sensor developed at the AFSC. At speed through water less than 2.5 knots, the center bobbins were resting on the bottom and, based on video observations, were actively rolling. At 3.0 knots, the bobbins were off the bottom by an average of 1.8 cm and were often not rolling but were sufficiently close to the bottom to leave a mud cloud. At 4.0 knots, the bobbins were off the bottom by an average of 6.7 cm and rarely left a mud cloud. At 5.0 knots, the bobbins were off the bottom by an average of 14.8 cm. However, at a speed through water greater than 4.5 knots the bottom contact sensor itself was observed to lift off the bottom and the predicted distance is likely substantially underestimated. The results of the study indicate that footrope contact, and therefore trawl efficiency, is not independent of trawl speed. This implies that reductions in the variance of survey CPUE might be achievable if towing speed was standardized to speed through water rather than speed over ground. Published by Elsevier Science B.V. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Somerton, DA (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE,Bld 4, Seattle, WA 98115 USA. NR 13 TC 31 Z9 31 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD SEP PY 2001 VL 53 IS 1 BP 17 EP 24 DI 10.1016/S0165-7836(00)00272-1 PG 8 WC Fisheries SC Fisheries GA 465FK UT WOS:000170578800002 ER PT J AU Larsen, DA Beckman, BR Dickhoff, WW AF Larsen, DA Beckman, BR Dickhoff, WW TI The effect of low temperature and fasting during the winter on metabolic stores and endocrine physiology (Insulin, insulin-like growth factor-I and thyroxine) of coho salmon, Oncorhynchus kisutch SO GENERAL AND COMPARATIVE ENDOCRINOLOGY LA English DT Article ID SPRING CHINOOK SALMON; GILTHEAD SEA BREAM; RAINBOW-TROUT; ATLANTIC SALMON; THYROID-HORMONES; ISOLATED HEPATOCYTES; TRUTTA-FARIO; HOMOLOGOUS RADIOIMMUNOASSAY; SMOLT TRANSFORMATION; GLYCOGEN-METABOLISM AB The objective of this study was to examine the effect of winter feeding and fasting at both high (10 degrees) and low (2.5 degrees) temperatures on growth, metabolic stores, and endocrinology of coho salmon. Treatments were as follows: warm-fed, warm-not fed, cold-fed, and cold-not fed during the winter (January-February). The following parameters were measured: length, weight, whole body lipid, liver glycogen, hepatosomatic index, and plasma levels of insulin, insulin-like growth factor-I (IGF-I), and thyroxine (T4). Warm-fed fish grew continuously throughout the experiment from 21.5 +/- 0.3 to 43.4 +/- 1.4 g and were larger than fish in the other treatments. Fish in all other treatments grew from 21.5 +/- 0.3 to approximately 32 g and showed depressed growth during January and February. During the winter, liver glycogen, hepatosomatic index, plasma insulin, and IGF-I were highly influenced by manipulations in rearing conditions, whereas whole body lipid and plasma T4 were less affected. Plasma insulin levels fluctuated dramatically (from 2 to 7 ng/ml) in the two cold-acclimated groups shortly after the change in temperature. In general, the plasma insulin levels of the warm-fed fish were the highest (8-9 ng/ml), those of the warm-not fed fish were the lowest (2-5 ng/ml), and those of the two cold-acclimated groups were more variable but intermediate. In contrast, plasma IGF-I levels showed a decline with temperature decrease (from 9 to 5 ng/ml) and more gradual changes than insulin with the change in feeding. The highest plasma IGF-I levels were found in the warm-fed fish (10-15 ng/ml), the lowest levels were in the cold-not fed fish (4-5 ng/ml), and those of the warm-not fed and cold-fed fish were intermediate. During the treatment period the T4 levels were relatively unaffected by manipulations in feeding and temperature compared with either insulin or IGF-I. These data suggest that the insulin, IGF-I, and thyroid axes are differentially regulated under changing seasonal and/or environmental conditions in yearling salmon. (C) 2001 Academic Press. C1 NW Fisheries Sci Ctr, Integrat Fish Biol Program, Natl Marine Fisheries Serv, Seattle, WA 98112 USA. Univ Washington, Sch Aquat & Fishery Sci, Seattle, WA 98195 USA. RP Larsen, DA (reprint author), NW Fisheries Sci Ctr, Integrat Fish Biol Program, Natl Marine Fisheries Serv, 2725 Montlake Blvd, Seattle, WA 98112 USA. NR 72 TC 111 Z9 118 U1 1 U2 15 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0016-6480 J9 GEN COMP ENDOCR JI Gen. Comp. Endocrinol. PD SEP PY 2001 VL 123 IS 3 BP 308 EP 323 DI 10.1006/gcen.2001.7677 PG 16 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 472GR UT WOS:000170975900007 PM 11589631 ER PT J AU Oettinger, G Haak, V Larsen, JC AF Oettinger, G Haak, V Larsen, JC TI Noise reduction in magnetotelluric time-series with a new signal-noise separation method and its application to a field experiment in the Saxonian Granulite Massif SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE data processing; electromagnetic methods; electromagnetic noise; magnetotellurics ID RESPONSE FUNCTION ESTIMATION; BIAS AB In the presence of large and continuous correlated noise signals in measured electric and magnetic time-series, even robust remote-reference methods give erroneous estimates of MT transfer functions. If clean remote time-series are available, it is possible to separate MT and correlated noise signals and to derive unbiased MT transfer functions with the signal-noise separation method (SNS) (Larsen et al. 1996). In practice, the remote time series also contain some noise and the results can be improved by using a second remote data set and the SNS-remote-reference technique. We tested this method with data from the Saxonian Granulite Massif (SGM), Germany, where strong correlated noise signals were detected. We used remote data which were recorded 350 km away and, for short periods, data from sites of the profile across the SGM itself (distance 5 km). To show the efficiency of the signal-noise separation we first determined a 'true' MT transfer function from time-series with low noise level. In a second step we reproduced the results from processing very noisy data sections. We were able to determine useful NIT transfer functions even when the MT variations have less than 10 per cent share of the measured variations. We identified dominant noise in the measured time-series from pipelines and trains. C1 Geoforschungszentrum Potsdam, D-11473 Potsdam, Germany. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP McKinsey & Co Inc, Konigsallee 60 C, D-40027 Dusseldorf, Germany. NR 22 TC 17 Z9 21 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0956-540X EI 1365-246X J9 GEOPHYS J INT JI Geophys. J. Int. PD SEP PY 2001 VL 146 IS 3 BP 659 EP 669 DI 10.1046/j.1365-246X.2001.00473.x PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 474VD UT WOS:000171126800007 ER PT J AU Brown, SS Stark, H Ciciora, SJ Ravishankara, AR AF Brown, SS Stark, H Ciciora, SJ Ravishankara, AR TI In-situ measurement of atmospheric NO3 and N2O5 via cavity ring-down spectroscopy SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DIFFERENTIAL OPTICAL-ABSORPTION AB We report the application of cavity ring-down spectroscopy (CaRDS), a high-sensitivity absorption technique, to the in-situ detection of both NO, and N2O5 in ambient air. The detection limit for NO,, measuring absorption in its strong, 662-nm band, is 0.3 pptv at STP (50 s integration time). Heating the air flow through the inlet thermally dissociates N2O5 to yield NO3, whose detection gives the ambient concentration of N2O5. The instrument was successfully field tested in March-April, 2001 at a site in the tropospheric boundary layer in Boulder, Colorado. This study is the first fast-response (5 s - I min), in-situ detection of NO3. It is also the first in-situ detection of N2O5 and the first observation of this species in the troposphere. Both NO, and N2O5 showed considerable temporal variability, highlighting the need for a fast-response instrument. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Brown, SS (reprint author), NOAA, Aeron Lab, R-AL2, Boulder, CO 80305 USA. RI Stark, Harald/E-7433-2010; Brown, Steven/I-1762-2013; Ravishankara, Akkihebbal/A-2914-2011; Ciciora, Steven/I-4916-2013 NR 12 TC 53 Z9 54 U1 3 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2001 VL 28 IS 17 BP 3227 EP 3230 DI 10.1029/2001GL013303 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 467JM UT WOS:000170698700003 ER PT J AU Broecker, WS Langdon, C Takahashi, T AF Broecker, WS Langdon, C Takahashi, T TI Factors controlling the rate of CaCO3 precipitation on Great Bahama Bank SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID SEAWATER; ARAGONITE; WHITINGS; CALCITE; DISSOCIATION; CHEMISTRY; PRESSURE; ORIGIN; ACID; MUD AB Measurements by Langdon et al. [2000] in the man-made mesocosm coral reef at Biosphere 2's ocean reveal a strong dependence of calcification rate on the degree of supersaturation of CaCO3 in seawater. A similar trend was previously encountered on the Bahama Banks, where Halimeda and other calcifiers are likely responsible for aragonite precipitation [Broecker and Takahashi, 1966]. In this paper we compare these two sets of results and conclude that the dependence on saturation state is significant but less strong in the Bahamas. However, it must be kept in mind that to some extent, the reduction in CaCO3 precipitation on the Bahama Banks may be due to impact of higher salinity on the growth of the calcifying algae. However, if, as many sedimentologists are convinced, the precipitation of CaCO3 on the Bahama Banks is inorganic [Macintyre and Reid, 1992; Milliman et al., 1993], then the comparison of the Bahamas and Biosphere 2 results for dependence of calcification rate on saturation state is telling us something quite different. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Div, Miami, FL 33149 USA. RP Broecker, WS (reprint author), Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. NR 17 TC 30 Z9 32 U1 6 U2 21 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 SEP PY 2001 VL 15 IS 3 BP 589 EP 596 DI 10.1029/2000GB001350 PG 8 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 468WJ UT WOS:000170780900005 ER PT J AU McNeil, BI Matear, RJ Tilbrook, B AF McNeil, BI Matear, RJ Tilbrook, B TI Does carbon 13 track anthropogenic CO2 in the Southern Ocean? SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID ATMOSPHERIC CO2; SURFACE OCEANS; INDIAN-OCEAN; C-13; DELTA-C-13; EXCHANGE; PACIFIC; SIGMA-CO2; DIOXIDE; WATERS AB A multiparametric linear regression technique was used for waters in the Southern Ocean to estimate the change in both delta (13) C-DIC (Delta delta C-13(DIC)) dissolved inorganic carbon (DIC) (Delta DIC) between 1978 and 1998, due to the accumulation of anthropogenic CO2. The observed decrease in delta C-13(DIC) at the surface, the Suess effect, was -0.015 +/- 0.003 parts per thousand yr(-1) in the Sub-Antarctic Zone and -0.005 +/- 0.003 parts per thousand yr(-1) in the Antarctic Zone, similar to values reported for the southern Indian Ocean [Gruber et al, 1999; Sonnerup et al., 2000]. To compare the Delta delta C-13(DIC) with Delta DIC, we used the ratio of these two anomalies (Delta RC = -Delta delta C-13(DIC)/Delta DIC parts per thousand (mu mol kg(-1))(-1)). Along the section, Delta RC ranged from 0.015 +/- 0.005 at 42 degreesS to 0.007 +/- 0.005 parts per thousand (mu mol kg(-1))(-l) at 54 degreesS. The spatial variability in Delta RC in the Southern Ocean reflects different timescales for processes controlling the uptake of C-13 from those controlling the uptake of C-12 and indicates that Delta delta C-13(DIC) decouples from Delta DIC poleward of the Sub-Antarctic Zone. The variations of Delta RC along the section suggest that the delta C-13(DIC) anomaly is not a good predictor of the anthropogenic CO(2)inventory in the Southern Ocean. Some methods for determining anthropogenic. CO2 uptake both on the global and regional scale assume the penetration depths of Delta delta C-13(DIC) to be the same as Delta DIC, which implies a constant value for Delta RC in the ocean at similar to0.016 parts per thousand (mu mol kg(-1))(-1) [Heimann and Maier-Reimer, 1996; Ortiz et al, 2000; Bauch et al, 2000]. The use of a constant Delta RC and the observed Delta delta C-13(DIC) to estimate anthropogenic CO2 could lead to an underestimate in the inventory of anthropogenic CO2 for the Southern Ocean by similar to 50%. C1 Univ Tasmania, Antarctic Cooperat Res Ctr, Hobart, Tas 7001, Australia. Univ Tasmania, Inst Antarctic & So Ocean Studies, Hobart, Tas 7001, Australia. CSIRO, Div Marine Res, Hobart, Tas 7001, Australia. RP McNeil, BI (reprint author), Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. RI matear, richard/C-5133-2011; Tilbrook, Bronte/A-1522-2012; OI Tilbrook, Bronte/0000-0001-9385-3827; McNeil, Ben/0000-0001-5765-7087 NR 31 TC 40 Z9 40 U1 1 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 EI 1944-9224 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD SEP PY 2001 VL 15 IS 3 BP 597 EP 613 DI 10.1029/2000GB001352 PG 17 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 468WJ UT WOS:000170780900006 ER PT J AU Bisdikian, C Bhagwat, P Golmie, N AF Bisdikian, C Bhagwat, P Golmie, N TI Wireless personal area networks SO IEEE NETWORK LA English DT Editorial Material C1 IBM Corp, Wireless Serv Platforms Grp, TJ Watson Res Ctr, Hawthorne, NY USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Bisdikian, C (reprint author), IBM Corp, Wireless Serv Platforms Grp, TJ Watson Res Ctr, Hawthorne, NY USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0890-8044 J9 IEEE NETWORK JI IEEE Netw. PD SEP-OCT PY 2001 VL 15 IS 5 BP 10 EP 11 DI 10.1109/MNET.2001.953228 PG 2 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 473ZL UT WOS:000171079600001 ER PT J AU Heidemann, J Mills, K Kumar, S AF Heidemann, J Mills, K Kumar, S TI Expanding confidence in network simulations SO IEEE NETWORK LA English DT Article AB Networking engineers increasingly depend on simulation to design and deploy complex; heterogeneous networks. Similarly, networking researchers increasingly depend on simulation to investigate the behavior and performance of new protocol designs. Despite such widespread use of simulation, today there exists little common understanding of the degree of validation required for various applications of simulation. Further, only limited knowledge exists regarding the effectiveness of known validation techniques. To investigate these issues, in May 1999 DARPA and NIST organized a workshop on Network Simulation Validation. This article reports on discussions and consensus about issues that arose at the workshop. We describe best current practices for validating simulations and for validating TCP models across various simulation environments. We also discuss interactions between scale and model validation and future challenges for the community. C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. NR 14 TC 14 Z9 14 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 0890-8044 J9 IEEE NETWORK JI IEEE Netw. PD SEP-OCT PY 2001 VL 15 IS 5 BP 58 EP 63 DI 10.1109/65.953234 PG 6 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 473ZL UT WOS:000171079600007 ER PT J AU Kim, T Choi, S Van Dyck, RE Bose, NK AF Kim, T Choi, S Van Dyck, RE Bose, NK TI Classified zerotree wavelet image coding and adaptive packetization for low-bit-rate transport SO IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY LA English DT Article DE adaptive packetization; error resilient; image compression; low bit rate; robust; subband coding; wavelet transform; zerotree ID NOISY CHANNELS; TRANSMISSION; COMPRESSION AB In this paper, a novel robust image-coding and adaptive-packetization algorithm suitable for very low bit-rate transport is suggested. This algorithm can be applied to any zerotree-based encoder, such as the embedded zerotree wavelet coder of Shapiro and set partitioning in hierarchical trees by Said and Pearlman. A very explicit segmentation and packetization method of an image bitstream, where the lowest frequency subband is separately encoded from the higher frequency subbands for unequal protection over a noisy channel, is proposed. The trees in the higher frequency subbands are split, classified, and assembled for efficient image coding and packetization according to their initial threshold and subband. The use of these classified trees enables one to make robust packets, while giving priority to some packets. In practice, each packet has a different initial threshold and can be decoded independently. In spite of additional overhead bits required for packetization, the algorithm reported is comparable to the original zerotree-based image coders at low bit rates. Additionally, simulation results show that the new method is resilient under severe packet losses. C1 Intel Corp, Technol & Res Labs, Chandler, AZ 85226 USA. Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. Natl Inst Stand & Technol, Adv Network Technol Div, Gaithersburg, MD 20899 USA. Penn State Univ, University Pk, PA 16802 USA. RP Intel Corp, Technol & Res Labs, Chandler, AZ 85226 USA. EM taekon.kim@intel.com; skchoi@psualum.com; vandyck@antd.nist.gov; nkb1@psu.edu NR 33 TC 14 Z9 15 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1051-8215 EI 1558-2205 J9 IEEE T CIRC SYST VID JI IEEE Trans. Circuits Syst. Video Technol. PD SEP PY 2001 VL 11 IS 9 BP 1022 EP 1034 DI 10.1109/76.946519 PG 13 WC Engineering, Electrical & Electronic SC Engineering GA 467GX UT WOS:000170695000004 ER PT J AU Lai, JS Song, BM Zhou, R Hefner, A Berning, DW Shen, CC AF Lai, JS Song, BM Zhou, R Hefner, A Berning, DW Shen, CC TI Characteristics and utilization of a new class of low on-resistance MOS-gated power device SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT Annual Meeting of the Industry-Applications-Society CY OCT 03-07, 1999 CL PHOENIX, ARIZONA SP Ind Applicat Soc DE cool MOS; high-voltage MOSFET; power MOSFET AB A new class of MOS-gated power semiconductor dew vices Cool MOS (Cool MOS is a trademark of Infineon Technologies, Germany) has recently been introduced with a supreme conducting characteristic that overcomes the high on-state resistance limitations of high-voltage power MOSFETs. From the application point of view, a very frequently asked question immediately arises: Does this device behave like a MOSFET or an insulated gate bipolar transistor (IGBT)? The goal of this paper is to compare and contrast the major similarities and differences between this device and the traditional MOSFET and IGBT. In this paper, the new device is fully characterized for its: 1) conduction characteristics; 2) switching voltage, current, and energy characteristics; 3) gate drive resistance effects; 4) output capacitance; and 5) reverse-bias safe operating areas. Experimental results indicate that the conduction characteristics of the new device are similar to the MOSFET but with much smaller on-resistance for the same chip and package size. The switching characteristics of the Cool MOS are also similar to the MOSFET in that they have fast switching speeds and do not have a current tail at turn-off. However, the effect of the gate drive resistance on the turn-off voltage rate of rise (dv/dt) is more like an IGBT. In other words, a very large gate drive resistance is required to have a significant change on dv/dt, resulting in a large turn-off delay. Overall, the device was found to behave more like a power MOSFET than like an IGBT. C1 Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Gen Atom Co, San Diego, CA 92186 USA. Gen Elect Corp Res & Dev, Schenectady, NY 12309 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Conexant Syst Inc, Newport Beach, CA 92660 USA. RP Lai, JS (reprint author), Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. OI Lai, Jihsheng/0000-0003-2315-8460 NR 7 TC 17 Z9 17 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD SEP-OCT PY 2001 VL 37 IS 5 BP 1282 EP 1289 DI 10.1109/28.952503 PG 8 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA 476FT UT WOS:000171216100009 ER PT J AU Zhu, HB Lai, JS Hefner, AR Tang, YQ Chen, CC AF Zhu, HB Lai, JS Hefner, AR Tang, YQ Chen, CC TI Modeling-based examination of conducted EMI emissions from hard- and soft-switching PWM inverters SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT Annual Meeting of the Industry-Applications-Society CY OCT 03-07, 1999 CL PHOENIX, AZ SP Ind Applicat Soc DE device modeling; electromagnetic interference; parasitic components; pulsewidth-modulated inverter; soft switching; time-domain reflectometry ID DRIVES; IGBT AB For the study of electromagnetic interference (EMI) mechanisms in pulsewidth-modulated inverters, this paper presents an analysis approach based on empirical models of the inverter components and their associated various parasitics. The power switching devices were modeled with a physics-based device modeling technique. Using time-domain reflectometry, we characterized the major parasitics in the device modules, passive components, cables, leads, and interconnects. Simulations of a full-bridge insulated gate bipolar transistor inverter were then carried out in the time domain under hard-switching and zero-voltage switching conditions. The simulated EMI spectra were compared with the experimental counterparts with the separation of common-mode and differential-mode EMI The comparisons verified the validity of the proposed modeling approach over most of the EMI frequency range. Also discussed in the paper are the soft-switching effects on the inverter's EMI. C1 Beacon Power Corp, Wilmington, MA 01887 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Ecostar Elect Dr Syst, Dearborn, MI 48120 USA. Forh Vehicle Elect Dept, Dearborn, MI 48124 USA. RP Zhu, HB (reprint author), Beacon Power Corp, Wilmington, MA 01887 USA. EM zhu@beaconpower.com; laijs@vt.edu; hefner@jetson.eeel.nist.gov; ytang2@ford.com; cchen4@ford.com OI Lai, Jihsheng/0000-0003-2315-8460 NR 19 TC 31 Z9 41 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD SEP-OCT PY 2001 VL 37 IS 5 BP 1383 EP 1393 DI 10.1109/28.952514 PG 11 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA 476FT UT WOS:000171216100020 ER PT J AU Alejos, O Della Tore, E AF Alejos, O Della Tore, E TI Dependence of magnetic after-effect processes in recording media on the moving parameter of the Preisach-Arrhenius model SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 9th Biennial IEEE Conference on Electromagnetic Field Computation (CEFC) CY JUN 04-07, 2000 CL MILWAUKEE, WISCONSIN SP IEEE DE hard magnetic materials; Preisach model; spin dynamics and relaxation AB The dependence of the after-effect processes in recording materials on the moving parameter under the Preisach-Arrhenius approach is studied by means of numerical simulations. Results reveal that the initial decay coefficient decreases as the moving parameter increases, but the transition becomes sharper and the steady state is more rapidly achieved. Furthermore, two equilibrium states can exist under some applied field conditions when the moving parameter takes a sufficiently high value. C1 George Washington Univ, Inst Magnet Res, Ashburn, VA 20147 USA. Univ Valladolid, Dept Elect & Elect, Fac Ciencias, Valladolid 47071, Spain. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Alejos, O (reprint author), George Washington Univ, Inst Magnet Res, Ashburn, VA 20147 USA. RI Alejos, Oscar/K-5745-2014 NR 7 TC 3 Z9 3 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2001 VL 37 IS 5 BP 3345 EP 3348 DI 10.1109/20.952610 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 478BA UT WOS:000171322000060 ER PT J AU Gentile, C Sznaier, M AF Gentile, C Sznaier, M TI An improved Voronoi-diagram-based neural net for pattern classification SO IEEE TRANSACTIONS ON NEURAL NETWORKS LA English DT Article DE pattern classification; Voronoi diagrams ID RECOGNITION AB In this brief paper, we propose a novel two-layer neural network to answer a point query in R-n which is partitioned into polyhedral regions. Such a task solves among others nearest neighbor clustering. As in previous approaches to the problem, our design is based on the use of Voronoi diagrams. However our approach results in substantial reduction of the number of neurons, completely eliminating the second layer, at the price of requiring only two additional clock steps. In addition, the design process is also simplified while retaining the main advantage of the approach, namely its ability to furnish precise values for the number of neurons and the connection weights necessitating neither trial and error type iterations nor ad hoc parameters. C1 Natl Inst Stand & Technol, Wireless Commun Technol Grp, Gaithersburg, MD 20899 USA. Penn State Univ, Dept Elect Engn, University Pk, PA 16802 USA. RP Gentile, C (reprint author), Natl Inst Stand & Technol, Wireless Commun Technol Grp, Gaithersburg, MD 20899 USA. NR 11 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 1045-9227 J9 IEEE T NEURAL NETWOR JI IEEE Trans. Neural Netw. PD SEP PY 2001 VL 12 IS 5 BP 1227 EP 1234 DI 10.1109/72.950151 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 474TN UT WOS:000171123100025 PM 18249949 ER PT J AU Ramesh, R Karthikeyan, S Raju, S Mohan, V Abhaikumar, V Hill, D AF Ramesh, R Karthikeyan, S Raju, S Mohan, V Abhaikumar, V Hill, D TI A modified approach to the characterization of EM environments irradiated by unknown sources SO IETE TECHNICAL REVIEW LA English DT Article ID INTERFERENCE; MODELS AB This paper presents a modified approach to the characterization of Electromagnetic (EM) environments irradiated by unknown sources. The approach based on application of Finite difference method (FDM) for the solution of Maxwell's equations subject to the constraints imposed by the measured values of the field at a relatively small number of measurement points and by the specified boundary conditions, The resulting III-conditioned system of equations is solved using Conjugate Gradient Method (CGM) which proves to be an accurate method for extraction of maximum information from minimum measurement effort. The applicability of the approach to EM environment characterization is demonstrated through two dimensional and three dimensional examples. C1 Univ Colorado, Boulder, CO 80309 USA. Thiagarajar Coll Engn, Dept Elect & Commun Engn, Madurai 625015, Tamil Nadu, India. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Ramesh, R (reprint author), Univ Colorado, Boulder, CO 80309 USA. NR 24 TC 0 Z9 0 U1 0 U2 1 PU INST ELECTRONICS TELECOMMUNICATION ENGINEERS PI NEW DELHI PA 2 INSTITUTIONAL AREA, LODI ROAD, NEW DELHI 110 003, INDIA SN 0255-9609 J9 IETE TECH REV JI IETE Tech. Rev. PD SEP-OCT PY 2001 VL 18 IS 5 BP 433 EP 440 PG 8 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 549ZP UT WOS:000175478400010 ER PT J AU Dillingham, J Wong-Ng, W Levin, I AF Dillingham, J Wong-Ng, W Levin, I TI Phase equilibria of the SrO-Yb2O3-CuOx system in air SO INTERNATIONAL JOURNAL OF INORGANIC MATERIALS LA English DT Article DE phase equilibria; SrO-Yb2O3-CuOx system; phase diagram; air ID CU-O; MAGNETIC-PROPERTIES; CRYSTAL-CHEMISTRY; SR; RE; CA; BA AB The phase diagram for the SrO-Yb2O3-CuOx system was, investigated in air. The solid solution (Sr14-xYbx)Cu24Oz (01) (the '14-24' phase) was the only ternary phase formed. This phase exhibits a smaller range of solid solution compared with similar phases containing larger lanthanide ions. Transmission electron microscopy (TEM) studies of (Sr,,Yb)Cu,,O, indicated that the phase was incommensurate, with the modulation wave vector q=(1/2-z)c*, z approximate to0.066. The Sr-analogs of the Ba2YbCu3O6+x high T-c superconductor and the associated BaYb2CuO5 'green phase' were not observed in the system. The ionic size of lanthanides 'R' in the SrO-R2O3-CuOx systems affects the number of compounds formed and their crystal chemistry. The phase diagrams exhibit a smaller number of solid-solution phases with decreasing size of R-cations, reflecting the lanthanide contraction. (C) 2001 Published by Elsevier Science Ltd. C1 Univ Maryland, Dept Geol, College Pk, MD 20874 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Dillingham, J (reprint author), Univ Maryland, Dept Geol, College Pk, MD 20874 USA. RI Levin, Igor/F-8588-2010 NR 29 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1466-6049 J9 INT J INORG MATER JI Int. J. Inorg. Mater. PD SEP PY 2001 VL 3 IS 6 BP 569 EP 573 DI 10.1016/S1466-6049(01)00015-0 PG 5 WC Chemistry, Inorganic & Nuclear; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 468DH UT WOS:000170742500023 ER PT J AU Zhang, NF AF Zhang, NF TI Combining process capability indices from a sequence of independent samples SO INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH LA English DT Article ID INDEXES AB Process capability indices such as C-p, C-pk and C-pm have been widely used in manufacturing for process assessment and for evaluation of purchasing decisions. Quality engineers and process operators are often asked to summarize the quality of a process by combining a sequence of C-pk or C-pm. This paper compares three different methods for combining the estimates of the process capability indices C-pk, C-pm and C-pmk from a sequence of independent samples. The criterion of minimum mean-squared-error (MSE) is applied. We find that, in general, methods for the combination of sample process capability indices based on the overall sample mean and pooled sample variance give smaller MSE than those based on weighted averages of the estimates of process capability indices. C1 Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. RP Zhang, NF (reprint author), Natl Inst Stand & Technol, Stat Engn Div, Gaithersburg, MD 20899 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0020-7543 J9 INT J PROD RES JI Int. J. Prod. Res. PD SEP PY 2001 VL 39 IS 13 BP 2769 EP 2781 DI 10.1080/00207540110051897 PG 13 WC Engineering, Industrial; Engineering, Manufacturing; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 468RD UT WOS:000170771200002 ER PT J AU Hanley, HJM Muzny, CD Ho, DL Glinka, CJ Manias, E AF Hanley, HJM Muzny, CD Ho, DL Glinka, CJ Manias, E TI A SANS study of organoclay dispersions SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Amer Soc Mech Engineers, Div Heat Transfer, Comm Thermophys Properties, Phys & Chem Properties Div HO UNIV COLORADO DE clay nanomaterial; Cloisite C15A; clusters; dispersions; ditallow; gel; montmorillonite; organic/inorganic complex; small-angle neutron scattering (SANS) ID SCATTERING AB Small-angle neutron scattering (SANS) is used to investigate the dispersion in toluene of various forms of the complex, Cloisite C15A. Cloisite is a commercially important exchanged clay prepared from montmorillonite and the cation di-tallow ammonium. Points discussed include estimates of the extent to which the complex is dispersed, the amount of organic clay platelet surface layer coverage, and possible network formation of the complex in the solvent. From power-law plots of the scattered neutron intensity versus the wave vector, it is estimated that C15A is well dispersed into clusters which consist of a stack of between three and seven di-tallow-coated montmorillonite platelets. The removal of excess di-tallow from the surface layer reduces the number of platelets in the cluster. Substitution of dimethydioctodecyl ammonium for the ditallow molecule promotes network formation. It is demonstrated that SANS is a powerful tool for examining these complicated organic/inorganic systems. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Hanley, HJM (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. RI Manias, Evangelos/A-7557-2011 NR 10 TC 18 Z9 18 U1 1 U2 4 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 2001 VL 22 IS 5 BP 1435 EP 1448 DI 10.1023/A:1012845104722 PG 14 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 504GD UT WOS:000172848200008 ER PT J AU Baker, J AF Baker, J TI Regional climate change SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Editorial Material C1 Natl Ocean & Atmospher Adm, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD FAL PY 2001 VL 18 IS 1 BP 18 EP 19 PG 2 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA 492MM UT WOS:000172172200013 ER PT J AU Van Dolah, FM Ramsdell, JS AF Van Dolah, FM Ramsdell, JS TI Review and assessment of in vitro detection methods for algal toxins SO JOURNAL OF AOAC INTERNATIONAL LA English DT Review ID PHOSPHATASE INHIBITION ASSAY; LINKED-IMMUNOSORBENT-ASSAY; SHELLFISH POISONING TOXINS; RECEPTOR-BINDING ASSAY; FLUORESCENT MICROPLATE ASSAY; SENSITIVE SODIUM-CHANNELS; TISSUE-CULTURE ASSAY; OKADAIC ACID; DOMOIC ACID; PARALYTIC SHELLFISH AB Algal toxins produced by marine and freshwater microalgae present a significant analytical challenge because of their complex structures and frequent occurrence as mixtures of structural congeners, which differ in toxic potencies and are present at varying proportions in contaminated samples. Rapid, sensitive in vitro detection methods specific for each class of algal toxins have been developed over the past decade, including immunoassays, enzyme inhibition assays, receptor assays, and cell assays. This review discusses the conceptual approaches to assay development and provides a detailed assessment of the use of in vitro detection methods for marine and freshwater algal toxins. C1 NOAA, Natl Ocean Serv, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, Charleston, SC 29412 USA. RP Van Dolah, FM (reprint author), NOAA, Natl Ocean Serv, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, 219 Ft Johnson Rd, Charleston, SC 29412 USA. NR 102 TC 25 Z9 28 U1 1 U2 9 PU AOAC INT PI GAITHERSBURG PA 481 N FREDRICK AVE, STE 500, GAITHERSBURG, MD 20877-2504 USA SN 1060-3271 J9 J AOAC INT JI J. AOAC Int. PD SEP-OCT PY 2001 VL 84 IS 5 BP 1617 EP 1625 PG 9 WC Chemistry, Analytical; Food Science & Technology SC Chemistry; Food Science & Technology GA 479UB UT WOS:000171421000040 PM 11601484 ER PT J AU Vogel, EM Edelstein, MD Suehle, JS AF Vogel, EM Edelstein, MD Suehle, JS TI Defect generation and breakdown of ultrathin silicon dioxide induced by substrate hot-hole injection SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DEPENDENT DIELECTRIC-BREAKDOWN; INTERFACE-TRAP GENERATION; INDUCED LEAKAGE CURRENTS; FIELD-EFFECT TRANSISTORS; GATE OXIDE BREAKDOWN; SIO2 THIN-FILMS; TEMPERATURE-DEPENDENCE; IMPACT IONIZATION; ELECTRON INJECTION; POSITIVE CHARGE AB Hole-induced bulk and interface defect generation and breakdown in ultrathin silicon dioxide (2.0 and 3.0 nm) are studied using substrate hot-hole injection. The results show that although these substrate hot holes are effective in creating electrically active damage in the dielectrics, these defects are very ineffective in causing breakdown as compared to those defects created by constant voltage tunneling stress. Identical to hole trapping in thicker oxides, substrate hot-hole defect generation was independent of electric field, decreased with decreasing thickness, and increased with decreasing temperature. The defect generation and breakdown of ultrathin oxides by substrate hot-hole stress is significantly different from that observed for constant voltage tunneling stress. The results suggest that the degradation and breakdown of ultrathin silicon dioxide cannot be explained by the trapping of hot holes alone. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Vogel, EM (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Bldg 225,Rm B360, Gaithersburg, MD 20899 USA. EM eric.vogel@nist.gov RI Vogel, Eric/A-7731-2008 OI Vogel, Eric/0000-0002-6110-1361 NR 75 TC 22 Z9 23 U1 0 U2 4 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 SEP 1 PY 2001 VL 90 IS 5 BP 2338 EP 2346 DI 10.1063/1.1389528 PG 9 WC Physics, Applied SC Physics GA 465MZ UT WOS:000170593900037 ER PT J AU Takeuchi, I Chang, K Sharma, RP Bendersky, LA Chang, H Xiang, XD Stach, EA Song, CY AF Takeuchi, I Chang, K Sharma, RP Bendersky, LA Chang, H Xiang, XD Stach, EA Song, CY TI Microstructural properties of (Ba, Sr)TiO3 films fabricated from BaF2/SrF2/TiO2 amorphous multilayers using the combinatorial precursor method SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN-FILMS; LIBRARIES; BAF2 AB We have investigated the microstructure of (Ba, Sr)TiO3 films fabricated from BaF2/SrF2/TiO2 amorphous multilayers. Rutherford backscattering spectroscopy and x-ray diffraction studies show that a controlled thermal treatment can interdiffuse the multilayers so as to create predominantly single-phase epitaxial (Ba, Sr)TiO3 films. A high resolution cross-sectional transmission electron microscopy investigation of the processed films shows that they consist of large epitaxial grains of (Ba, Sr)TiO3 with atomically sharp interfaces with the LaAlO3 substrates. In addition, we have identified regions where polycrystalline and transient phases exist in small pockets in the film matrix. The results here indicate that the combinatorial thin-film synthesis using precursors can produce (Ba, Sr)TiO3 films in combinatorial libraries which exhibit properties similar to those films made by conventional techniques. (C) 2001 American Institute of Physics. C1 Univ Maryland, Dept Mat Sci & Engn, Small Smart Syst Ctr, College Pk, MD 20742 USA. Univ Maryland, Dept Phys, Ctr Superconduct Res, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Takeuchi, I (reprint author), Univ Maryland, Dept Mat Sci & Engn, Small Smart Syst Ctr, College Pk, MD 20742 USA. RI Xiang, Xiaodong/A-9445-2012; Stach, Eric/D-8545-2011; Xiang, Xiaodong/A-5936-2017 OI Stach, Eric/0000-0002-3366-2153; NR 14 TC 9 Z9 12 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2001 VL 90 IS 5 BP 2474 EP 2478 DI 10.1063/1.1388563 PG 5 WC Physics, Applied SC Physics GA 465MZ UT WOS:000170593900057 ER PT J AU Arkoosh, MR Clemons, E Huffman, P Kagley, AN AF Arkoosh, MR Clemons, E Huffman, P Kagley, AN TI Increased susceptibility of juvenile Chinook salmon to vibriosis after exposure to chlorinated and aromatic compounds found in contaminated urban estuaries SO JOURNAL OF AQUATIC ANIMAL HEALTH LA English DT Article ID POLYCHLORINATED-BIPHENYLS; ONCORHYNCHUS-TSHAWYTSCHA; PUGET-SOUND; WASHINGTON; FISH AB Saltwater-adapted juvenile chinook salmon Oncorhynchus tshawytscha exposed to aromatic and chlorinated compounds, representative of contaminants found in urban estuaries in Puget Sound, have a higher susceptibility to vibriosis than do fish exposed only to the solvent vehicle. Susceptibility to vibriosis was assessed by examining the percent cumulative mortality of the salmon after exposure to the bacterial pathogen Vibrio anguillarum. The aromatic and chlorinated compounds examined consisted of a sediment extract from the Hylebos Waterway that was enriched in butadienelike compounds (chlorinated-enriched Hylebos Waterway sediment extract (CHWSE]), a model mixture of polycyclic aromatic hydrocarbons (PAHs), a polychlorinated biphenyl mixture (Aroclor 1254), hexachlorobutadiene (HCBD), and 7,12-dimethylbenz[a]anthracene (DMBA). Two trials were conducted. In trial 1, the percent cumulative mortality of juvenile chinook salmon exposed to V. anguillarum after receiving either CHWSE, HCBD, or the model mixture of PAHs ranged from 28% to 31% compared with the 16% observed in the acetone: emulphor control group at 7 d post-bacterial challenge. In trial 2, the net cumulative mortality of juvenile chinook salmon exposed to V. anguillarum after receiving either DMBA or Aroclor 1254 ranged from 46% to 49% compared with the 25% observed in the acetone:emulphor control group at 9 d postchallenge. The differences in mortality between groups of fish in the treated and control groups in both trials were significant at P less than or equal to 0.05. These findings suggest that a higher predisposition to infection and subsequent disease can occur in salmon exposed to chemical contaminants found in urban estuaries of Puget Sound, Washington. C1 NOAA, Environ 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. RP Arkoosh, MR (reprint author), NOAA, Environ Conservat Div, NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, 2030 S Marine Sci Dr, Newport, OR 97365 USA. NR 28 TC 53 Z9 57 U1 2 U2 14 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0899-7659 J9 J AQUAT ANIM HEALTH JI J. Aquat. Anim. Health PD SEP PY 2001 VL 13 IS 3 BP 257 EP 268 DI 10.1577/1548-8667(2001)013<0257:ISOJCS>2.0.CO;2 PG 12 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA 479AP UT WOS:000171382000009 ER PT J AU Rainwater, JC Friend, DG Hanley, HJM Harvey, AH Holcomb, CD Laesecke, A Magee, JW Muzny, C AF Rainwater, JC Friend, DG Hanley, HJM Harvey, AH Holcomb, CD Laesecke, A Magee, JW Muzny, C TI Forum 2000: Fluid properties for new technologies, connecting virtual design with physical reality SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Editorial Material AB Forum 2000 was held at the 14th Symposium for Thermophysical Properties, with all symposium attendees invited. The forum addressed the present needs and priorities for thermophysical properties measurements and the challenges facing the experimental community. Seven distinguished panelists presented brief overviews of issues related to a wide variety of subjects, and three discussion periods were held. Topics included whether simulation can replace experiment, properties needs for new miniaturization techniques, real problems such as nuclear waste cleanup, data needs for electrolyte systems and new generations of electric power plants, and data needs for unconventional materials such as molten metals and soft solids. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Rainwater, JC (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80305 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 3 TC 3 Z9 3 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 2001 VL 46 IS 5 BP 1002 EP 1006 DI 10.1021/je010002e PG 5 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 476EN UT WOS:000171213400002 ER PT J AU Andersen, WC Sievers, RE Lagalante, AF Bruno, TJ AF Andersen, WC Sievers, RE Lagalante, AF Bruno, TJ TI Solubilities of cerium(IV), terbium(III), and iron(III) ss-diketonates in supercritical carbon dioxide SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Amer Soc Mech Engineers, Div Heat Transfer, Comm Thermophys Properties, Phys & Chem Properties Div HO UNIV COLORADO ID FLUID EXTRACTION; CHELATING-AGENTS; METALS AB The solubilities of the cerium(IV), terbium(III), and iron(III) chelates of the anions of 2,2,7-trimethyl-3,5-octanedionate, H(tod), 2,2,6,6-tetramethyl-3,5-octanedionate, H(thd), and 2,4-pentanedionate, H(acac), were measured in supercritical carbon dioxide by near-infrared spectroscopy from 313 to 333 K and 10 to 35 MPa with a high-pressure optical cell. Solubilities increased in the order acac < thd < tod for all metal beta -diketonates, with Ce(tod)(4), Tb(tod)(3), and Fe(tod)(3) an order of magnitude more soluble than Ce(thd)4, Tb(thd)(3), and Fe(acac)(3), respectively. For the larger metal ions, Ce4+ and Tb3+, the flexibility of the isobutyl group in the tod ligand creates a more lipophilic shell around the central metal ion, increasing the solubility of the chelate in CO2. These observations indicate that the isobutyl group is at least as CO2-philic as the tert-butyl moiety. The experimental solubilities were correlated using the model proposed by Chrastil. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Boulder, CO 80305 USA. RP Sievers, RE (reprint author), Univ Colorado, Dept Chem & Biochem, Campus Box 215, Boulder, CO 80309 USA. NR 15 TC 34 Z9 34 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 2001 VL 46 IS 5 BP 1045 EP 1049 DI 10.1021/je000257c PG 5 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 476EN UT WOS:000171213400011 ER PT J AU Hansen, BN Harvey, AH Coelho, JAP Palavra, AMF Bruno, TJ AF Hansen, BN Harvey, AH Coelho, JAP Palavra, AMF Bruno, TJ TI Solubility of capsaicin and ss-carotene in supercritical carbon dioxide and in halocarbons SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV Colorado, Boulder, CO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Amer Soc Mech Engineers, Heat Transfer Div, Comm Thermophys Properties HO UNIV Colorado ID BETA-CAROTENE; NITROUS-OXIDE; DENSE CO2; FLUIDS; SOLIDS; MPA AB The solubilities of beta -carotene and capsaicin have been measured in supercritical carbon dioxide and in difluoromethane (R-32) and 1,1,1,2-tetrafluoroethane (R-134a) in the liquid phase at temperatures near and somewhat below their critical points. The solubility of beta -carotene was also measured in 1,1,1-trifluoroethane (R-143a). The temperatures of the measurements ranged from 35 degreesC to 55 degreesC for capsaicin (up to 85 degreesC in R-32) and from 40 degreesC to 70 degreesC for beta -carotene. The solubilities were determined using an HPLC system for capsaicin and a static high-pressure cell for beta -carotene, and the amounts of products extracted were measured spectroscopically. At similar temperatures and densities, the solubility of capsaicin in the halocarbons was higher than that in carbon dioxide; there was not such a clear trend for beta -carotene. Where the data covered a sufficient density range, they (along with literature data for the solutes in carbon dioxide) were analyzed with the semiempirical density-based model of Mendez-Santiago and Teja. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. Univ Tecn Lisboa, Inst Super Tecn, Lisbon, Portugal. RP Harvey, AH (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80305 USA. RI Coelho, Jose/G-2626-2011; Palavra, Antonio/H-9235-2012 OI Coelho, Jose/0000-0001-8118-0864; Palavra, Antonio/0000-0003-4838-1589 NR 16 TC 37 Z9 37 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 2001 VL 46 IS 5 BP 1054 EP 1058 DI 10.1021/je000255s PG 5 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 476EN UT WOS:000171213400013 ER PT J AU Linstrom, PJ Mallard, WG AF Linstrom, PJ Mallard, WG TI The NIST Chemistry WebBook: A chemical data resource on the internet SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Amer Soc Mech Engineers, Div Heat Transfer, Comm Thermophys Properties, Phys & Chem Properties Div HO UNIV COLORADO ID MOLECULES AB The NIST Chemistry WebBook (http://webbook.nist.gov) is an Internet site that provides access to chemical and physical property data both from NIST and other sources. The site was established in 1996 and has grown to encompass a wide variety of thermochemical, ion energetics, solubility, and spectroscopic data. The thermochemical data available include enthalpies of formation, enthalpies of phase transitions, and heat capacities. Thermochemical properties of many reactions that support enthalpy of formation values are provided. Automated tools are used to check data prior to its inclusion in the web site. Most of the collections in the site provide extensive coverage of the literature in their field and include relevant metadata such as the experiment type or important auxiliary data. These features make the site an excellent tool for data evaluation. A major goal of the project was to provide convenient access to all types of chemical data. Several challenges were encountered in the development of systems and conventions for concisely and accurately displaying chemical data on the Internet. The next phase of the evolution of the site will be the addition of tools to aid researchers in getting data from the site. Data from the site have found applications in industrial, research, and educational settings. Usage patterns for the site will be discussed. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Linstrom, PJ (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 100 Bur Dr,Stop 8380, Gaithersburg, MD 20899 USA. OI Linstrom, Peter/0000-0003-3204-3454; Mallard, Wm. Gary/0000-0003-2158-5098 NR 8 TC 44 Z9 45 U1 1 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 2001 VL 46 IS 5 BP 1059 EP 1063 DI 10.1021/je000236i PG 5 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 476EN UT WOS:000171213400014 ER PT J AU Polikhronidi, NG Abdulagatov, IM Magee, JW Batyrova, RG AF Polikhronidi, NG Abdulagatov, IM Magee, JW Batyrova, RG TI Isochoric heat capacity for toluene near phase transitions and the critical point SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Amer Soc Mech Engineers, Div Heat Transfer, Comm Thermophys Properties, Phys & Chem Properties Div HO UNIV COLORADO ID AROMATIC-HYDROCARBONS; NITROGEN TETROXIDE; COEXISTENCE-CURVE; CRITICAL REGION; CARBON-DIOXIDE; PRESSURES; DENSITIES; BEHAVIOR; MPA AB New measurements of isochoric heat capacity C-V for toluene near phase transitions and the critical point are presented. Measurements were made with a high-temperature, high-pressure, adiabatic calorimeter of nearly constant volume. The inner volume of the calorimeter is (104.441 +/-0.002) cm(3) at 297.15 K and 0.1 MPa. The heat capacity of the empty calorimeter C-0 was measured by use of a reference fluid (helium-4) with a well-known heat capacity (uncertainty of 0.1%). The temperature of the sample was measured with a 10 Omega PRT with an uncertainty of 10 mK. Uncertainties of the heat capacity measurements are estimated to be 2% to 3%. Measurements were made in the single- and two-phase regions. The experimental values of phase transition temperatures T-S(rho) and single- and two-phase isochoric heat capacities (C-V1, C-V2) on each measured isochore were determined by use of a quasi-static thermogram method. Measurements were made along 12 isochores between (199.3 and 525.0) kg.m(-3) in the temperature range from (411 to 620) K. The temperature dependence of single- (C-V1) and two-phase (C-V2) isochoric heat capacities along the coexistence curve and along near-critical isochores, the isochoric heat capacity jumps DeltaC(V), and the density and temperature on the coexistence curve near the critical point are discussed. The values of the critical parameters (critical temperature, density, and pressure) of toluene were derived from the experimental measurements of density, temperature, and heat capacity at saturation in the immediate vicinity of the critical point. The scaling equations were used to express measured values of C-V and density along the coexistence curve. The results of the measurements are compared with values calculated from various equations of state. The data can be used to improve the equation of state and to develop a crossover equation in the critical region. C1 Russian Acad Sci, Dagestan Sci Ctr, Inst Phys, Makhachkala 367005, Dagestan, Russia. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Abdulagatov, IM (reprint author), Russian Acad Sci, Dagestan Sci Ctr, Inst Phys, M Yaragskogo Str 94, Makhachkala 367005, Dagestan, Russia. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 49 TC 25 Z9 25 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 2001 VL 46 IS 5 BP 1064 EP 1071 DI 10.1021/je000269y PG 8 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 476EN UT WOS:000171213400015 ER PT J AU Bazaev, AR Abdulagatov, IM Magee, JW Bazaev, EA Rabezkii, MG AF Bazaev, AR Abdulagatov, IM Magee, JW Bazaev, EA Rabezkii, MG TI PVT measurements for toluene in the near-critical and supercritical regions SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Amer Soc Mech Engineers, Div Heat Transfer, Comm Thermophys Properties, Phys & Chem Properties Div HO UNIV COLORADO ID VOLUMETRIC PROPERTIES; VIRIAL-COEFFICIENTS; AQUEOUS MIXTURES; HIGH-PRESSURES; N-HEPTANE; WATER; DENSITIES; METHANE; HEXANE; 400-K AB The PVT relationships of toluene were measured in the near-critical and supercritical regions. Measurements were made using a constant-volume piezometer immersed in a precision thermostat. The volume of the piezometer V-PT was corrected for both temperature and pressure expansions. The temperature was measured with a 10 Omega platinum resistance thermometer (PRT-10) with an uncertainty of 10 mK. Pressure was measured by means of a dead-weight gauge with an uncertainty of (0.0015 to 0.002) MPa. Uncertainties of the density measurements are estimated to be (0.05 to 0.10)%, depending on the experimental pressure and temperature. The volume of the piezometer V-PT was calibrated using a reference fluid (water) with well-known PVT properties at various temperatures and pressures. Measurements were made along various near-critical and supercritical isotherms between (591 and 673) K at pressures from (4 to 36) MPa. The measured PVT data for toluene were compared with values calculated from equations of state and previous measurements of other authors. The accuracy of the method was confirmed by PVT measurements for pure water in the critical and supercritical regions. C1 Russian Acad Sci, Dagestan Sci Ctr, Inst Geothermal Problems, Makhachkala 367030, Dagestan, Russia. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Abdulagatov, IM (reprint author), Russian Acad Sci, Dagestan Sci Ctr, Inst Geothermal Problems, Shamilya Str 39, Makhachkala 367030, Dagestan, Russia. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 35 TC 11 Z9 11 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 2001 VL 46 IS 5 BP 1089 EP 1094 DI 10.1021/je0002686 PG 6 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 476EN UT WOS:000171213400020 ER PT J AU Duarte-Garza, HA Magee, JW AF Duarte-Garza, HA Magee, JW TI Isochoric p-rho-T measurements on {(x)CO2+(1-x)C2H6,x approximate to 0.25, 0.49, 0.74} from (220 to 400) K at pressures to 35 MPa SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Amer Soc Mech Engineers, Div Heat Transfer, Comm Thermophys Properties, Phys & Chem Properties Div HO UNIV COLORADO ID CARBON-DIOXIDE; VIRIAL-COEFFICIENTS; MIXTURES; ETHANE AB The p-rho -T relationships were measured for binary hydrocarbon mixtures containing carbon dioxide (CO2) and ethane (C2H6). Temperatures ranged from (220 to 400) K with pressures up to 35 MPa. Measurements of p-rho -T were conducted on compressed gaseous and liquid samples with the mole fraction compositions {(x)CO2 + (1 - x)C2H6} for x = 0.251 68, 0.492 33, and 0.739 79. These mixtures were prepared gravimetrically to match, within 0.000 12 mole fraction, the compositions (0.251 66, 0.492 45, 0.739 78) of three mixtures which had been used by three laboratories for measurements of key thermophysical. properties, including the density. For the p-rho -T apparatus used in this study, the uncertainty of the temperature is 0.03 K, and for pressure, it is 0.01% at p>3 MPa and 0.05% at p<3 MPa. The principal source of uncertainty in density is the cell volume (28.5 cm(3)) whose standard uncertainty is 0.003 cm(3). When all components of experimental uncertainty are considered, the expanded relative uncertainty (with a coverage factor k = 2 and thus a two-standard-deviation estimate) of the density measurements is estimated to be 0.05%. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Chem Sci & Technol Lab, Boulder, CO 80305 USA. RP Magee, JW (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Chem Sci & Technol Lab, 325 Broadway, Boulder, CO 80305 USA. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 22 TC 4 Z9 4 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 2001 VL 46 IS 5 BP 1095 EP 1100 DI 10.1021/je010061s PG 6 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 476EN UT WOS:000171213400021 ER PT J AU Kuroki, T Kagawa, N Endo, H Tsuruno, S Magee, JW AF Kuroki, T Kagawa, N Endo, H Tsuruno, S Magee, JW TI Specific heat capacity at constant volume for water, methanol, and their mixtures at temperatures from 300 K to 400 K and pressures to 20 MPa SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Amer Soc Mech Engineers, Div Heat Transfer, Comm Thermophys Properties, Phys & Chem Properties Div HO UNIV COLORADO ID THERMODYNAMIC PROPERTIES; 573 K AB Specific heat capacities at constant volume (c(v)) of water, methanol, and their mixtures were measured with a new adiabatic calorimeter. Temperatures ranged from 300 K to 400 K, and pressures ranged to 20 MPa. Densities were determined at the initial and final end points during each calorimetric experiment. The calorimeter is a twin-cell type whose sample and reference cells (33 cm(3)) and their shields are heated by electric power. The cells are surrounded by a high vacuum. During the experiment, the heating power was carefully controlled so that the cell temperature increased uniformly. The reference cell was always evacuated and was heated with a constant current. The temperature of the sample cell tracked that of the reference cell temperature by means an automatic control system. Automated sample pressure measurements were made with a crystal quartz transducer. The expanded relative uncertainty for c(v) is estimated to be 1% for liquid-phase measurements, and for density it is about 0.2%. C1 Natl Def Acad, Yokosuka, Kanagawa 2390811, Japan. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Kagawa, N (reprint author), Natl Def Acad, Yokosuka, Kanagawa 2390811, Japan. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 19 TC 22 Z9 22 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 2001 VL 46 IS 5 BP 1101 EP 1106 DI 10.1021/je0002437 PG 6 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 476EN UT WOS:000171213400022 ER PT J AU Bauchat, JR Busby, WH Garmong, A Swanson, P Moore, J Lin, M Duan, C AF Bauchat, JR Busby, WH Garmong, A Swanson, P Moore, J Lin, M Duan, C TI Biochemical and functional analysis of a conserved IGF-binding protein isolated from rainbow trout (Oncorhynchus mykiss) hepatoma cells SO JOURNAL OF ENDOCRINOLOGY LA English DT Article ID GROWTH-FACTOR-I; MORONE-SAXATILIS; STRIPED BASS; MESSENGER-RNA; COHO SALMON; EXPRESSION; ZEBRAFISH; HORMONE; PLASMA; SERUM AB Rainbow trout (Oncorhynchus mykiss) serum contains several IGF-binding proteins (IGFBPs) that specifically bind to IGFs. The structures of these fish IGFBPs have not been determined and their physiological functions are poorly defined. In this study, we identified a 30 kDa IGFBP present in rainbow trout serum and secreted by cultured trout hepatoma cells. This IGFBP binds to IGFs but not to insulin. This IGFBP was purified to homogeneity using a three-step procedure involving Phenyl-Sepharose chromatography, IGF-I affinity chromatography and reverse-phase HPLC. Affinity cross-linking studies indicated that this IGFBP binds to IGF-I with a higher affinity than to IGF-II. N-terminal sequence analysis of the trout IGFBP suggests that it shares high sequence identity with that of human IGFBP-1 in the N-terminal region. When added to cultured fish and human cells, the trout IGFBP inhibited IGF-I-stimulated DNA synthesis and cell proliferation in a concentration-dependent manner. The inhibitory effect of the fish IGFBP was comparable to those of human IGFBP-1 and -4. These results indicate that the IGFBP molecule is structurally and functionally conserved in evolutionarily ancient vertebrate species such as bony fish. C1 Univ Michigan, Dept Biol, Ann Arbor, MI 48109 USA. Univ N Carolina, Dept Med, Chapel Hill, NC 27599 USA. Natl Marine Fisheries Serv, Seattle, WA 98112 USA. Univ Calif Bodega, Marine Lab, Bodega Bay, CA 94923 USA. RP Duan, C (reprint author), Univ Michigan, Dept Biol, Nat Sci Bldg, Ann Arbor, MI 48109 USA. EM cduan@umich.edu NR 35 TC 32 Z9 35 U1 0 U2 2 PU BIOSCIENTIFICA LTD PI BRISTOL PA EURO HOUSE, 22 APEX COURT WOODLANDS, BRADLEY STOKE, BRISTOL BS32 4JT, ENGLAND SN 0022-0795 J9 J ENDOCRINOL JI J. Endocrinol. PD SEP PY 2001 VL 170 IS 3 BP 619 EP 628 PG 10 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 472PB UT WOS:000170991700014 PM 11524242 ER PT J AU Pivarnik, L Ellis, P Wang, X Reilly, T AF Pivarnik, L Ellis, P Wang, X Reilly, T TI Standardization of the ammonia electrode method for evaluating seafood quality by correlation to sensory analysis SO JOURNAL OF FOOD SCIENCE LA English DT Article DE seafood quality; sensory analysis; ammonia; ion-selective electrode; total volatile bases ID ION-SELECTIVE ELECTRODE; VOLATILE BASES; FISH AB Ammonia ion-selective electrode (ISE) measurements, reported as apparent ammonia, were correlated to expert sensory assessments of 6 different fish species stored on ice and at room temperature. Total volatile base nitrogen (TVB-N), trimethylamine nitrogen (TMA-N), and apparent ammonia showed the same development trend during storage. ISE measurements and TVB concentrations had a correlation of r(2) = 0.92. Sensory assessment, using a 1- to 100-mm line scale with values >50 considered unacceptable, resulted in an r(2) between sensory scores and ISE measurements of 0.78. Regression analysis predicted 19.6 mg/100 g of apparent ammonia in fish tissue at the sensory limit of 50, regardless of storage conditions. ISE measurements could be used in predicting borderline quality and decomposition. C1 Univ Rhode Isl, Dept Food Sci & Nutr, Kingston, RI 02881 USA. Rhode Isl Dept Hlth, Food Chem Lab, Providence, RI 02908 USA. Natl Marine Fisheries Serv, Seafood Inspect Div, Natl Sensory Branch, Silver Spring, MD 20910 USA. RP Pivarnik, L (reprint author), Univ Rhode Isl, Dept Food Sci & Nutr, Kingston, RI 02881 USA. EM Pivarnik@uri.edu NR 25 TC 17 Z9 18 U1 2 U2 8 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0022-1147 J9 J FOOD SCI JI J. Food Sci. PD SEP PY 2001 VL 66 IS 7 BP 945 EP 952 DI 10.1111/j.1365-2621.2001.tb08217.x PG 8 WC Food Science & Technology SC Food Science & Technology GA 481FB UT WOS:000171508300007 ER PT J AU Duewer, DL Kline, MC Redman, JW Newall, PJ Reeder, DJ AF Duewer, DL Kline, MC Redman, JW Newall, PJ Reeder, DJ TI NIST mixed stain studies #1 and #2: Interlaboratory comparison of DNA quantification practice and short tandem repeat multiplex performance with multiple-source samples SO JOURNAL OF FORENSIC SCIENCES LA English DT Article DE forensic science; blood stains; DNA fingerprinting; DNA typing; evaluation studies; interlaboratory comparison; polymerase chain reaction; reproducibility of results; semen stains; short tandem repeat (STR) alleles ID PCR AB The Mixed Stain Study 1 (MSS1, Apr.-Nov. 1997) and Mixed Stain Study 2 (MSS2, Jan.-May 1999) evaluated multiplexed short-tandem repeat (STR) DNA typing systems with samples containing DNA from more than one source. These interlaboratory challenge studies evaluated forensic STR measurement, interpretation, and reporting practice using well-characterized samples of very different analytical difficulty. None of the relatively few errors reported in either exercise resulted in a false identification of a reference sources several errors in evaluating the unknown source in three-source samples would hinder matching the profile in any archival database. None of the measurement anomalies reported is associated with any particular STR multiplex; all DNA amplification anomalies are associated with inefficient DNA extraction, inaccurate DNA quantitation, and/or analytical threshold policies. C1 Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Biotechnol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Ctr Forens Sci, Res Dev & Def Projects, Toronto, ON M7A 2G8, Canada. RP Kline, MC (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RI Duewer, David/B-7410-2008 NR 20 TC 22 Z9 23 U1 1 U2 2 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0022-1198 J9 J FORENSIC SCI JI J. Forensic Sci. PD SEP PY 2001 VL 46 IS 5 BP 1199 EP 1210 PG 12 WC Medicine, Legal SC Legal Medicine GA 471FL UT WOS:000170917800027 PM 11569565 ER PT J AU Hale, PD Clement, TS Williams, DF Balta, E Taneja, ND AF Hale, PD Clement, TS Williams, DF Balta, E Taneja, ND TI Measuring the frequency response of gigabit chip photodiodes SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article DE equivalent circuits; frequency response; measurement; photodetectors; photodiodes ID NOSE CALIBRATION PROCEDURE; SAMPLING OSCILLOSCOPES AB We describe a calibration and measurement procedure for determining the intrinsic frequency response of gigabit chip photodiodes embedded in simple test fixtures. The procedure is unique because we make the measurements in the time domain using a calibrated oscilloscope, and we then apply frequency-domain mismatch corrections to remove the effects of the fixture, bias T, and cables from the measurements. We demonstrate the procedure on photodiodes with an active region of approximately 150-mum diameter excited by short 800-nm wavelength optical pulses. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. UDT Sensors Inc, Hawthorne, CA 90250 USA. RP Hale, PD (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. RI Clement, Tracy/A-8885-2008; Hale, Paul/B-1737-2013 NR 11 TC 13 Z9 16 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD SEP PY 2001 VL 19 IS 9 BP 1333 EP 1339 DI 10.1109/50.948281 PG 7 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA 473FH UT WOS:000171029500011 ER PT J AU Soulen, RJ Colwell, JH Fogle, WE AF Soulen, RJ Colwell, JH Fogle, WE TI The superconductive critical magnetic field of beryllium SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article AB We have measured the temperature dependence of the superconductive critical magnetic field of three samples of beryllium from three different sources. The irregular geometric shape of one sample prevented a complete analysis of the data, but the data for the other two samples were well represented by the BCS model of superconductivity. The values of T-c and H-c(0) are found to be sample dependent. For the purest sample studied, T-c=24.34 +/- 0.02 mK, H-c(0) = 107.7 +/- 0.2 muT and (gamma /V) = 32.9 +/- 0.3 muJ/cm(3) K-2. By a very small extrapolation of the data cis a function of purity, it is inferred that the critical parameters for pure Be are: T-c = 24.38 +/- 0.02 mK. H-c(0) = 107.9 muT +/- 0.2 muT and (gamma /V) = 33.0 +/- 0.3 muJ/cm(3) K-2. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Soulen, RJ (reprint author), USN, Res Lab, Code 6340, Washington, DC 20375 USA. NR 23 TC 2 Z9 2 U1 2 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD SEP PY 2001 VL 124 IS 5-6 BP 515 EP 526 PG 12 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 489KV UT WOS:000171991300001 ER PT J AU Pearce, JV Azuah, RT Stirling, WG Dimeo, RM Sokol, PE Adams, MA AF Pearce, JV Azuah, RT Stirling, WG Dimeo, RM Sokol, PE Adams, MA TI High resolution measurements of the temperature dependence of the roton energy of superfluid He-4 SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article ID COLLECTIVE EXCITATIONS; LIQUID-HE-4 AB New measurements of the roton excitations in superfluid He-4 have been made using the IRIS spectrometer (energy resolution similar to 20 ge Vat the roton energy) at the ISIS spallation neutron source. The roton energy was determined over a temperature range of 0.56 to 1.61 K. High resolution (energy resolution < 1 mu eV) neutron inelastic scattering measurements by Andersen et al.(2) of the dependence of the He-4 roton energy on temperature have shown significant deviations from the expected behaviour,, the temperature variation was found to be discontinuous and slower than predicted by the established roton-roton interaction theory due to Bedell, Pines and Zawadowski (BPZ).(3) We find that our results can be described well by the BPZ theory over this temperature range and we do not observe the anomalous behaviour reported by Andersen et al. We offer some explanations as to the origin of this apparent disagreement. C1 Univ Liverpool, Oliver Lodge Lab, Dept Phys, Liverpool L69 7ZE, Merseyside, England. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England. Paul Scherrer Inst, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. RP Pearce, JV (reprint author), Univ Liverpool, Oliver Lodge Lab, Dept Phys, Liverpool L69 7ZE, Merseyside, England. NR 12 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD SEP PY 2001 VL 124 IS 5-6 BP 573 EP 586 DI 10.1023/A:1012221912995 PG 14 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 489KV UT WOS:000171991300004 ER PT J AU Luy, B Barchi, JJ Marino, JP AF Luy, B Barchi, JJ Marino, JP TI (SE)-E-3-E.COSY methods for the measurement of F-19 associated scalar and dipolar coupling constants SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE (SE)-E-3; E.COSY; fluorine; RNA; scalar couplings; residual dipolar couplings ID E.COSY-TYPE MEASUREMENT; NMR-SPECTROSCOPY; COHERENCE TRANSFER; SPIN SYSTEMS; RNA; HETERONUCLEAR; PROTEINS; POLARIZATION; INTERMEDIATE; TRANSITIONS AB A H-1-F-19 spin state selective excitation ((SE)-E-3) pulse sequence element has been applied in combination with IH homonuclear mixing to create E.COSY-type experiments designed to measure scalar J(HF2') and J(HH2') and residual dipolar D-HF2' and D-HH2' couplings in 2'-deoxy-2'-fluoro-sugars. The H-1-F-19 (SE)-E-3 pulse sequence element, which resembles a simple INEPT sequence, achieves spin-state-selective correlation between geminal H-1-F-19 spin pairs by linear combination of in-phase F-19 magnetization and anti-phase magnetization evolved from H-1. Since the (SE)-E-3 sequence converts both F-19 and H-1 steady-state polarization into observable coherences, an approximately twofold signal increase is observed for fully relaxed H-1-F-19 spin pairs with respect to a standard H-1 coupled F-19 1D experiment. The improved sensitivity and resolution afforded by the use of H-1-F-19 (SE)-E-3 E.COSY-type experiments for measuring couplings is demonstrated on the nucleoside 9-(2',3'-dideoxy-2'-fluoro-beta -D-threo-pentofuranosyl)adenine (beta -FddA) and on a selectively 2'-fluorine labeled 21mer RNA oligonucleotide. C1 Univ Maryland, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NIST, Rockville, MD 20850 USA. NCI, Med Chem Lab, FCRDC, Frederick, MD 21702 USA. RP Marino, JP (reprint author), Univ Maryland, Ctr Adv Res Biotechnol, 9600 Gudelsky Dr, Rockville, MD 20850 USA. RI Luy, Burkhard/I-1918-2013; Barchi Jr., Joseph/N-3784-2014 OI Luy, Burkhard/0000-0001-9580-6397; FU NIGMS NIH HHS [GM 59107-01] NR 23 TC 21 Z9 21 U1 1 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD SEP PY 2001 VL 152 IS 1 BP 179 EP 184 DI 10.1006/jmre.2001.2386 PG 6 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 472QD UT WOS:000170995700020 PM 11531377 ER PT J AU Ochoa, J Sheinbaum, J Badan, A Candela, J Wilson, D AF Ochoa, J Sheinbaum, J Badan, A Candela, J Wilson, D TI Geostrophy via potential vorticity inversion in the Yucatan Channel SO JOURNAL OF MARINE RESEARCH LA English DT Article ID CALIFORNIA CURRENT; ADCP MEASUREMENTS; OMEGA-EQUATION; LOOP CURRENT; CIRCULATION; VELOCITY; OCEAN; FLOW; GULF; SEA AB It has become common practice to measure ocean current velocities together with the hydrography by lowering an ADCP on typical CTD casts. The velocities and densities thus observed are considered to consist mostly of a background contribution in geostrophic balance, plus internal waves and tides, A method to infer the geostrophic component by inverting the linearized potential vorticity (P-V) provides plausible geostrophic density and velocity distributions. The method extracts the geostrophic balance closest to the measurements by minimizing the energy involved in the difference, supposed to consist of P-V-free anomalies. The boundary conditions and the retention of P-V by the geostrophic estimates follow directly from the optimization, which is based on simple linear dynamics and avoids both the use of the thermal wind equation on the measured density, and the classical problem of a reference velocity. By construction, the transport in geostrophic balance equals the measured one. Tides are the largest source of error in the calculation. The method is applied to six ADCP/CTD surveys made across the Yucatan Channel in the springs of 1997 and 1998 and in the winter of 1998-1999. Although the time interval between sections is sometimes close to one inertial period, large variations on the order of 10 percent are found from one section to the next. Transports range from 20 to 31 Sv with a net average close to 25 Sv, consisting of 33 Sv of inflow into the Gulf of Mexico and 8 Sv of outflow into the Caribbean Sea. The highest velocities are 2.0 m sec(-1) into the Gulf of Mexico near the surface on the western side of the channel, decreasing to 0.1 m sec(-1) by 400 to 500 m depth. Beneath the core of the Yucatan Current a countercurrent, with speeds close to 0.2 m sec(-1) and an average transport of 2 Sv, hugs the slopes of the channel from 500 to 1500 m depth. Our data show an additional 6 Sv of return flow within the same depth range over the abrupt slope near Cuba, which is likely to be the recirculating fraction of the Yucatan Current deep extention, unable to outflow through the Florida Straits. The most significant southerly flows do not occur in the deepest portion of the channel, but at depths around 1000 m. C1 CICESE, Oceanog Fis, Ensenada, Baja California, Mexico. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Ochoa, J (reprint author), CICESE, Oceanog Fis, Apdo Postal 2732, Ensenada, Baja California, Mexico. OI /0000-0001-6121-3972 NR 43 TC 52 Z9 52 U1 0 U2 1 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 SEP PY 2001 VL 59 IS 5 BP 725 EP 747 DI 10.1357/002224001762674917 PG 23 WC Oceanography SC Oceanography GA 501WU UT WOS:000172709700003 ER PT J AU Heyliger, P Ugander, P Ledbetter, H AF Heyliger, P Ugander, P Ledbetter, H TI Anisotropic elastic constants: Measurement by impact resonance SO JOURNAL OF MATERIALS IN CIVIL ENGINEERING LA English DT Article ID ULTRASOUND; SOLIDS AB Modes of unrestrained free vibration of rectangular parallelepipeds are excited by impact and combined with solutions to the weak form of the equations of motion corresponding to the 3D equations of elasticity and periodic motion to provide estimates for the elastic constants of anisotropic materials. This method has been previously applied to isotropic materials based on analytic approximations for the relationship between elastic constants and resonant frequencies. The present approach extends this procedure to account for material anisotropy and variance in specimen dimension, and we apply this technique to several specimens of differing material type, constitution, and shape to compute various components of the elastic stiffness tensor. Our results are in very good agreement with those found by other techniques. C1 Colorado State Univ, Dept Civil Engn, Ft Collins, CO 80523 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Boulder, CO 80303 USA. RP Heyliger, P (reprint author), Colorado State Univ, Dept Civil Engn, Ft Collins, CO 80523 USA. NR 20 TC 5 Z9 5 U1 0 U2 2 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0899-1561 J9 J MATER CIVIL ENG JI J. Mater. Civ. Eng. PD SEP-OCT PY 2001 VL 13 IS 5 BP 356 EP 363 DI 10.1061/(ASCE)0899-1561(2001)13:5(356) PG 8 WC Construction & Building Technology; Engineering, Civil; Materials Science, Multidisciplinary SC Construction & Building Technology; Engineering; Materials Science GA 476CU UT WOS:000171209300006 ER PT J AU Lee, JS Kim, DY AF Lee, JS Kim, DY TI Space-charge concepts on grain boundary impedance of a high-purity yttria-stabilized tetragonal zirconia polycrystal SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ELECTRICAL-CONDUCTIVITY; IONIC-CONDUCTIVITY; DEFECT CHEMISTRY; SINGLE-CRYSTAL; Y-TZP; CERAMICS; INTERFACES; ELECTROLYTES; TEMPERATURES; RESISTIVITY AB A detailed impedance analysis using the brick-layer model is performed on a high-purity yttria-stabilized tetragonal zirconia polycrystal (Y-TZP). Space-charge impedance is generally formulated and expressions for the respective space-charge models are therefrom derived depending on whether dopant ions are mobile or immobile. Pronounced yttrium segregation in Y-TZP is also considered in the analysis in that the dopant profile is assumed to be frozen from a high-temperature equilibrium distribution. Comparison with experimental observations shows that the electrically measured grain-boundary thickness corresponds to the Schottky-barrier width, slightly modified by the dopant segregation. The grain-boundary resistance is not consistent with any space-charge models and the strong defect interaction due to the yttrium enrichment is suggested to be mainly responsible. C1 Seoul Natl Univ, Ctr Microstruct Sci & Mat, Seoul 151742, South Korea. Seoul Natl Univ, Sch Mat Sci & Engn, Seoul 151742, South Korea. RP Lee, JS (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Lee, Jong-Sook/D-1035-2013 OI Lee, Jong-Sook/0000-0002-2227-0808 NR 58 TC 37 Z9 37 U1 0 U2 6 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD SEP PY 2001 VL 16 IS 9 BP 2739 EP 2751 DI 10.1557/JMR.2001.0374 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 470XZ UT WOS:000170898900040 ER PT J AU Zabransky, M Ruzicka, V Domalski, ES AF Zabransky, M Ruzicka, V Domalski, ES TI Heat capacity of liquids: Critical review and recommended values. Supplement 1 SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Review DE bibliography; correlating equations; critically evaluated data; heat capacity; liquids ID EXCESS MOLAR VOLUMES; DIFFERENTIAL SCANNING CALORIMETRY; TETRAHYDROFURAN PLUS CYCLOHEXANE; LOW-TEMPERATURE CALORIMETRY; PICKER FLOW CALORIMETER; IDEAL-GAS ENTHALPIES; + NORMAL-HEPTANE; POLYNUCLEAR AROMATIC MOLECULES; UNUSUAL COMPOSITION DEPENDENCE; BIOCHEMICAL MODEL COMPOUNDS AB A study was carried out in which new experimental data on heat capacities of pure liquid organic and some inorganic compounds were compiled, critically evaluated, and recommended values provided. Compounds included in the compilation have a melting point below 573 K. The bulk of the compiled data covers data published in the primary literature between 1993 and 1999 and some data of 2000. However, some data from older sources were also included. The data were taken from almost 1030 literature references. Parameters of correlating equations for temperature dependence of heat capacities of liquids were developed. This paper is an update of a two volume monograph entitled Heat Capacity of Liquids: Critical Review and Recommended Values (96ZAB/RUZ) that was published in 1996 in the Journal of Physical and Chemical Reference Data as Monograph No. 6 and was the product of the IUPAC Project No. 121/11/87. (C) 2002 by the U.S. Secretary of Commerce on behalf of the United States. All rights reserved. C1 Inst Chem Technol, Dept Phys Chem, CR-16628 Prague 6, Czech Republic. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Zabransky, M (reprint author), Inst Chem Technol, Dept Phys Chem, CR-16628 Prague 6, Czech Republic. RI Zabransky, Milan/A-2214-2009; Ruzicka, Vlastimil/B-8905-2008 NR 1040 TC 77 Z9 77 U1 1 U2 46 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD SEP-OCT PY 2001 VL 30 IS 5 BP 1199 EP 1689 PG 491 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA 513EJ UT WOS:000173364700002 ER PT J AU Park, YG Bryan, K AF Park, YG Bryan, K TI Comparison of thermally driven circulations from a depth-coordinate model and an isopycnal-layer model. Part II: The difference and structure of the circulations SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID DIAPYCNAL DIFFUSION; GENERAL-CIRCULATION; SUBPOLAR GYRE; OCEAN; THERMOCLINE; SENSITIVITY; BOUNDARY AB Thermally driven ocean circulations in idealized basins are calculated with two well-known model codes. one based on depth-level coordinates and the other based on isopycnal coordinates. In addition, the two models have very different representations of convection. In the level-coordinate model. convective adjustment is used, while in the isopycnal-coordinate model. convection is simulated by a transformation of the surface layer to the layer below. Both models indicate a three-layer structure in the circulation. The lower and middle layers have a flow structure that corresponds with the classical abyssal circulation models. The upper flow is strongly constrained by the buoyancy flux field at the upper surface and the convective parameterization. The model with convective adjustment and level coordinates is dominated by an eastward flow, which sinks to subsurface level at the eastern boundary. It lacks any indication of a surface cyclonic flow, even in the vicinity of sinking at the northern wall. On the other hand, in the model based on density coordinates the eastward surface flow turns to the north at the eastern boundary and forms a pronounced cyclonic circulation at high latitudes. Due to the cyclonic circulation, the coldest surface water is found near the northwestern corner, while in the level model the coldest water is near the northeastern corner. The isopycnal model appears to be a more realistic representation of the real ocean since both wind and the thermohaline circulation are thought to contribute to the North Atlantic subarctic cyclonic gyre. Although the zonally averaged buoyancy flux produced by the two model codes is the same. the actual patterns of buoyancy flux at the surface are not similar at high latitudes. This suggests that the two types of numerical models would indicate very different air-sea interaction if coupled to atmospheric models and used to simulate climate. The application of the Gent-McWilliams parameterization of mesoscale eddies to the model with z coordinates and convective adjustment reduces the differences between the surface circulation of the two models by a small amount. C1 Korea Ocean Res & Dev Inst, Marine Environm & Climate Change Lab, Ansan, South Korea. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Park, YG (reprint author), Korea Ocean Res & Dev Inst, Marine Environm & Climate Change Lab, POB 29, Seoul 425600, South Korea. EM ypark@kordi.re.kr RI Park, Young-Gyu /H-4585-2013 NR 25 TC 10 Z9 10 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 2001 VL 31 IS 9 BP 2612 EP 2624 DI 10.1175/1520-0485(2001)031<2612:COTDCF>2.0.CO;2 PG 13 WC Oceanography SC Oceanography GA 473QZ UT WOS:000171060600005 ER PT J AU Sorte, CJ Peterson, WT Morgan, CA Emmett, RL AF Sorte, CJ Peterson, WT Morgan, CA Emmett, RL TI Larval dynamics of the sand crab, Emerita analoga, off the central Oregon coast during a strong El Nino period SO JOURNAL OF PLANKTON RESEARCH LA English DT Article ID NORTHEAST PACIFIC; OCEAN; VARIABILITY; DECAPODA AB Populations of the sand crab, Emerita analoga, are well established on the California coast. However, populations in Oregon occur sporadically and appear to be restocked by larvae drifting north from California. Due to increased northward transport in winter during El Nino events, we would expect that larval recruitment to northern populations should be higher during these periods. This hypothesis was tested by comparing larval abundances between non-El Nino and El Nino years, 1997 and 1998, respectively. In 1997, larval abundances and seasonality were similar to historical data from 1969-71. First zoeal (Z1) stage larvae were present during these summers, but in low numbers, indicating th at E. analoga spawned off the coast of Oregon. In 1998, strong larval recruitment from the south occurred, demonstrated by a large number of fifth zoeal stage (Z5) larvae collected off Oregon in April and May. The large numbers of Z1 found in summer 1998 indicate that the Z5, which arrived from, California earlier that spring, successfully recruited to adulthood and reproduced. These data indicate that Oregon E.analoga populations are probably dependent on larvae travelling from California in the Davidson Current. It follows that this species could be used as an indicator of coastal current fluctuations such as those seen during El Nino events. C1 Whitman Coll, Dept Biol, Walla Walla, WA 99362 USA. Oregon State Univ, Hatfield Marine Sci Ctr, NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Newport, OR 97365 USA. Oregon State Univ, Hatfield Marine Sci Ctr, Cooperat Inst Marine Resources Studies, Newport, OR 97365 USA. RP Sorte, CJ (reprint author), Arizona State Univ, Dept Biol, Tempe, AZ 85287 USA. NR 21 TC 19 Z9 19 U1 0 U2 9 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0142-7873 J9 J PLANKTON RES JI J. Plankton Res. PD SEP PY 2001 VL 23 IS 9 BP 939 EP 944 DI 10.1093/plankt/23.9.939 PG 6 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 477MF UT WOS:000171286800003 ER PT J AU Shirley, EL AF Shirley, EL TI Fraunhofer diffraction effects on total power for a Planckian source SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE diffraction; Fraunhofer; Planckian; power; radiometry AB An algorithm for computing diffraction effects on total power in the case of Fraunhofer diffraction by a circular lens or aperture is derived. The result for Fraunhofer diffraction of monochromatic radiation is well known, and this work reports the result for radiation from a Planckian source. The result obtained is valid at all temperatures. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Shirley, EL (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM eric.shirley@nist.gov NR 6 TC 4 Z9 4 U1 0 U2 8 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 SEP-OCT PY 2001 VL 106 IS 5 BP 775 EP 779 DI 10.6028/jres.106.036 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 490JB UT WOS:000172047800001 PM 27500046 ER PT J AU Hobbs, TG AF Hobbs, TG TI Environmental radiation monitoring at NBS/NIST from 1960 through 2000 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE electret detectors; environment; G-M detectors; ion chamber detectors; radiation; radioactivity; scintillation detectors; thermoluminescent detectors ID ELECTRET ION CHAMBERS AB The program for monitoring the environment in and about the site of the National Bureau of Standards, now the National Institute of Standards and Technology, at its Gaithersburg, Maryland location began in 1960. The program includes measurements of radiation fields at the fence line of the site and of radionuclides in samples of soil, water, and biota taken within and around the site. A variety of instruments and equipment, processes and procedures, and measurement devices has been employed. To date, no measurement from the routine program has exhibited any result that could be attributed to any effluent or other effect of the radiological work conducted at the site; that includes the NIST Research Reactor, the now defunct Linear Electron Accelerator (LINAC) and other accelerators, radiochemistry, and scaled source operations. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Hobbs, TG (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM thomas.hobbs@nist.gov NR 9 TC 0 Z9 0 U1 0 U2 9 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 SEP-OCT PY 2001 VL 106 IS 5 BP 781 EP 794 DI 10.6028/jres.106.037 PG 14 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 490JB UT WOS:000172047800002 PM 27500047 ER PT J AU Parr, AC West, JB King, MRF Ueda, K Dehmer, PM Dehmer, JL AF Parr, AC West, JB King, MRF Ueda, K Dehmer, PM Dehmer, JL TI Vibrational branching ratios and asymmetry parameters in the photoionization of CO2 in the region between 650 angstrom and 840 angstrom SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE asymmetry; autoionization; branching ratios; parameters; photoelectron spectra ID PHOTOELECTRON ANGULAR-DISTRIBUTIONS; CARBON-DIOXIDE; AUTOIONIZATION; RESONANCES; MOLECULES; SPECTRUM; SPECTROSCOPY; IONIZATION; RADIATION; STATES AB The vibrational branching ratios and asymmetry parameters for CO2 have been determined in the wavelength region of 650 Angstrom to near the ionization onset at about 840 Angstrom. The study was performed using synchrotron radiation from the Daresbury storage ring that was dispersed with a 5 m grating monochomator that afforded resolution of 0.1 Angstrom to 0.2 Angstrom. This resolution allowed the study of the branching ratios and asymmetry parameters with enough detail to see the changes in the parameters within the pronounced autoionization structure in CO2 in this wavelength region. While the electron spectrometer resolution was not sufficient to resolve the spin orbit and Renner-Teller splitting in the photoelectron spectra, we are able to fit the data with a model that identifies the major structure in terms of the symmetric stretch and elements of the asymmetric stretch and bending modes. A calculation of the expected relative vibrational excitations based upon the Franck-Condon principle clearly showed non-Franck-Condon behavior in some of the vibrational-electronic transitions. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. SERC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. Tohoku Univ, Sci Measurements Res Inst, Sendai, Miyagi 980, Japan. US DOE, Off Basic Energy Sci, Germantown, MD 20874 USA. Natl Sci Fdn, Arlington, VA 22230 USA. RP Parr, AC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 43 TC 4 Z9 4 U1 0 U2 15 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 SEP-OCT PY 2001 VL 106 IS 5 BP 795 EP 822 DI 10.6028/jres.106.038 PG 28 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 490JB UT WOS:000172047800003 PM 27500048 ER PT J AU Murthy, AV Tsai, BK Saunders, RD AF Murthy, AV Tsai, BK Saunders, RD TI Transfer calibration validation tests on a heat flux sensor in the 51 mm high-temperature blackbody SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE blackbodies; heat flux; sensors; thermal radiation; transfer calibration AB Facilities and techniques to characterize heat flux sensors are under development at the National Institute of Standards and Technology. As a part of this effort, a large aperture high-temperature blackbody was commissioned recently. The graphite tube blackbody, heated electrically, has a cavity diameter of 51 mm and can operate up to a maximum temperature of 2773 K. A closed-loop cooling system using a water-to-water heat exchanger cools electrodes and the outer reflecting shield. This paper describes the newly developed blackbody facility and the validation tests conducted using a reference standard Schmidt-Boelter heat flux sensor. The transfer calibration results obtained on the Schmidt-Boelter sensor agreed with the previous data within the experimental uncertainty limits. C1 Aerotech Inc, Hampton, VA 23666 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Saunders Enterprises, Gaithersburg, MD 20878 USA. RP Murthy, AV (reprint author), Aerotech Inc, Hampton, VA 23666 USA. EM murthy.annageri@nist.gov; benjamin.tsai@nist.gov; robert.saunders@nist.gov NR 6 TC 5 Z9 5 U1 0 U2 9 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 SEP-OCT PY 2001 VL 106 IS 5 BP 823 EP 831 DI 10.6028/jres.106.039 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 490JB UT WOS:000172047800004 PM 27500049 ER PT J AU Fick, SE Palmer, CH AF Fick, SE Palmer, CH TI Precision ultrasonic wave measurements with simple equipment SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE displacement; inexpensive; interferometer; precision; ultrasonic wave ID FABRY-PEROT-INTERFEROMETER; OPTICAL-DETECTION AB We describe the design and construction of a relatively simple, inexpensive laser interferometer system for accurate measurements of ultrasonic surface displacement waveforms in reasonably friendly environments. We show how analysis of a single waveform can provide both the calibration constant required for absolute measurements and an estimate of the uncertainty of these measurements. We demonstrate the performance of this interferometer by measuring ultrasonic waveforms generated by a novel conical-element ultrasonic transducer. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Johns Hopkins Univ, Baltimore, MD USA. RP Fick, SE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM steven.fick@nist.gov NR 13 TC 3 Z9 3 U1 0 U2 8 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 SEP-OCT PY 2001 VL 106 IS 5 BP 833 EP 841 DI 10.6028/jres.106.040 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 490JB UT WOS:000172047800005 PM 27500050 ER PT J AU Domen, JK Domen, SR AF Domen, JK Domen, SR TI Studies of excess heat and convection in a water calorimeter SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE absorbed dose; calorimeter; convection; excess heat; finite element analysis; thermistor; water calorimeter. ID PERFORMANCE; RADIATION AB To explain a difference of 0.5 % between the absorbed-dose standards of the National Institute of Standards and Technology (NIST) and the National Research Council of Canada (NRCC), Seuntjens et al. suggest the fault lies with the NIST water calorimeter being operated at 22 degreesC and the method with which the measurements were made. Their calculations show that this difference is due to overprediction of temperature rises Of Six Consecutive Co-60 radiation runs at NIST. However, the consecutive runs they refer to were merely preliminary measurements to determine the procedure for the NIST beam calibration. The beam calibration was determined from only two consecutive runs followed by water circulation to re-establish temperature equilibrium. This procedure was used for measurements on 77 days, with 32 runs per day. Convection external to the glass cylindrical detector assembly performed a beneficial role. It aided (along with conduction) in increasing the rate of excess heat transported away from the thin cylindrical wall. This decreased the rate of heat conducted toward the axially located thermistors. The other sources of excess heat are the: (1) non-water materials in the temperature probe, and (2) exothermic effect of the once-distilled water external to the cylinder. Finite-element calculations were made to determine the separate and combined effects of the excess heat sources for the afterdrift. From this analysis, extrapolation of the measured afterdrifts of two consecutive runs to mid radiation leads to an estimated overprediction of no more than about 0.1 %. Experimental measurements contradict the calculated results of Seuntjens et al. that convective motion (a plume) originates from the thermistors operated with an electrical power dissipation as low as 0.6 LW, well below the measured threshold of 50 muW. The method used for detecting a plume was sensitive enough to measure a convective plume (if it had started) down to about the 10 muW power level. Measurements also contradict the NRCC calculations in predicting the behavior of the NIST afterdrifts. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Domen, JK (reprint author), USA, Qual Engn Directorate, Armament Res Dev & Engn Ctr, Picatinny Arsenal, NJ 07806 USA. EM jdomen@pica.army.mil; SteveDomen@aol.com NR 14 TC 6 Z9 6 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 SEP-OCT PY 2001 VL 106 IS 5 BP 843 EP 856 DI 10.6028/jres.106.041 PG 14 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 490JB UT WOS:000172047800006 PM 27500051 ER PT J AU Guo, L Colby, RH Lin, MY Dado, GP AF Guo, L Colby, RH Lin, MY Dado, GP TI Micellar structure changes in aqueous mixtures of nonionic surfactants SO JOURNAL OF RHEOLOGY LA English DT Article ID ANGLE NEUTRON-SCATTERING; OXIDE) TRIBLOCK COPOLYMERS; OSCILLATORY SHEAR MEASUREMENTS; AMPHIPHILIC BLOCK-COPOLYMERS; LIGHT-SCATTERING; AGGREGATION BEHAVIOR; SELECTIVE SOLVENTS; SUPRAMOLECULAR ASSEMBLIES; SPHERICAL MICELLES; ORGANIC ADDITIVES AB Rheology and small-angle neutron scattering are used to probe the structure of nonionic surfactant mixtures in water. Small amounts of a C(14) diol (Surfynol((R)) 104) cause enormous structural and rheological changes when added to aqueous solutions of an ethylene oxide-propylene oxide-ethylene oxide triblock copolymer (Pluronic((R)) P105). The C(14) diol is only soluble up to 0.1 wt % in pure water, but can be added in large quantities to aqueous solutions of the copolymer, The hydrophobic diol incorporates into the existing copolymer micelles and causes a cascade of changes in the micelle structure, with resultant changes in rheology. Particularly striking is the spherical to worm-like micelle transition, where the viscosity changes by a factor of more than 10(4). (C) 2001 The Society of Rheology. C1 Penn State Univ, University Pk, PA 16802 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Air Prod & Chem Inc, Allentown, PA 18195 USA. RP Colby, RH (reprint author), Penn State Univ, University Pk, PA 16802 USA. EM rhc@plmsc.psu.edu NR 58 TC 29 Z9 30 U1 2 U2 18 PU JOURNAL RHEOLOGY AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0148-6055 J9 J RHEOL JI J. Rheol. PD SEP-OCT PY 2001 VL 45 IS 5 BP 1223 EP 1243 DI 10.1122/1.1389315 PG 21 WC Mechanics SC Mechanics GA 470DN UT WOS:000170855300012 ER PT J AU Skirl, S Krause, R Wiederhorn, SM Rodel, J AF Skirl, S Krause, R Wiederhorn, SM Rodel, J TI Processing and mechanical properties of Al2O3/Ni3Al composites with interpenetrating network microstructure SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ADVANCED STRUCTURAL CERAMICS; INTERMETALLIC COMPOUNDS; AL2O3/AL COMPOSITES; MELT-INFILTRATION; BEHAVIOR; STRENGTH; FRACTURE; NI3AL; COMMERCIALIZATION; OXIDATION AB Composites with microstructures of interpenetrating networks were manufactured by gas pressure infiltration of Ni3Al into porous preforms of aluminum oxide. Composites with Ni-3,Al contents of between 15% and 30% by volume were made and evaluated mechanically at temperatures between room temperature and 1000 degreesC. The fracture strength, the fracture toughness, Young's modulus, and the thermal expansion coefficient were measured for each composite and test condition and were correlated with the microstructures of the composites. Composites with low Ni3Al contents had strengths below 400 Wa, presumably due to microcracking along the interface between the Ni3Al and the Al2O3. The composite with the highest content of Ni3Al, 30 vol%, had a mean fracture strength of 675 +/- 16 MPa, a Weibull modulus of 23.9, and a room-temperature toughness of 9.2 +/- 0.5 MPa(.)m(1/2). C1 Univ Technol, Dept Mat Sci, D-64287 Darmstadt, Germany. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Skirl, S (reprint author), Univ Technol, Dept Mat Sci, D-64287 Darmstadt, Germany. NR 34 TC 24 Z9 24 U1 0 U2 9 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 2001 VL 84 IS 9 BP 2034 EP 2040 PG 7 WC Materials Science, Ceramics SC Materials Science GA 472BF UT WOS:000170962600018 ER PT J AU Quinn, TJ Mizroch, SA AF Quinn, TJ Mizroch, SA TI Comment SO JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION LA English DT Editorial Material ID ANIMAL ABUNDANCE; BAYESIAN METHODS C1 Univ Alaska Fairbanks, Sch Fisheries & Ocean Sci, Juneau Ctr, Juneau, AK 99801 USA. Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Quinn, TJ (reprint author), Univ Alaska Fairbanks, Sch Fisheries & Ocean Sci, Juneau Ctr, Juneau, AK 99801 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 2001 VL 96 IS 455 BP 928 EP 933 PG 6 WC Statistics & Probability SC Mathematics GA 467XP UT WOS:000170729300016 ER PT J AU Ohwada, K Hirota, K Rehrig, PW Gehring, PM Noheda, B Fujii, Y Park, SEE Shirane, G AF Ohwada, K Hirota, K Rehrig, PW Gehring, PM Noheda, B Fujii, Y Park, SEE Shirane, G TI Neutron diffraction study of the irreversible R-M-A-M-C phase transition in single crystal Pb[(Zn1/3Nb2/3)(1-x)Ti-x]O-3 SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE relaxor; ferroelectric; PZN-xPT; phase transition; electric field; neutron scattering ID X-RAY-DIFFRACTION; PIEZOELECTRIC PROPERTIES AB Single crystals of the relaxor PZN-xPT display an enormously strong piezoelectric character. Recent x-ray scattering studies have revealed novel electric-field induced phase transitions in PZN-8%PT. As-grown crystals exhibit a rhombohedral structure that, under application of an electric field oriented along [001]. transforms into a monoclinic (M-A) phase, and then irreversibly to another monoclinic (M-C) phase with increasing field strength. Since the latter phase change is very unusual, its transition sequence hats been investigated by using triple-axis neutron scattering techniques so that the "skin effect" observed by x-ray scattering can be avoided, and the entire crystal bulk is probed. Contour maps of the elastic scattering have been mapped out in each phase in the (H0L) zone with high q-resolution. Increasing the field strength within the Me phase induces a sharp c-axis jump around 15 kV/cm. This jump was observed easily with x-rays in previous studies, but it was not observed in 5 different crystals examined with neutrons. A subsequent high-energy x-ray study of the same crystals showed that the c-a-xis jump is distributed within the crystal volume, thereby washing out the jump. The observed R-M-A-M-C transformational path is in perfect accord with very recent first principles calculations by Bellaiche, Garcia, and Vanderbilt in the PZT system. C1 Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan. Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. NIST, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11073 USA. Fraunhofer IBMT Technol Ctr Hialeah, Hialeah, FL 33010 USA. RP JAERI, Spring-8,1-1-1 Kouto Mikazuki Cho Sayo, Hyogo 6795148, Japan. RI Hirota, Kazuma/C-6797-2008; OI Gehring, Peter/0000-0002-9236-2046 NR 17 TC 56 Z9 56 U1 1 U2 19 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD SEP PY 2001 VL 70 IS 9 BP 2778 EP 2783 DI 10.1143/JPSJ.70.2778 PG 6 WC Physics, Multidisciplinary SC Physics GA 476FZ UT WOS:000171216700042 ER PT J AU Ilavsky, J Stalick, JK Wallace, J AF Ilavsky, J Stalick, JK Wallace, J TI Thermal spray yttria-stabilized zirconia phase changes during annealing SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE neutron scattering; phase composition; Rietveld analysis; yttria-stabilized zirconia ID PARAMETERS; COATINGS AB Phase stability of thermal barrier deposits made from yttria partially stabilized zirconia (Y-PSZ) is a requirement for extended service lifetime. The response of Y-PSZ plasma-sprayed deposits to annealing at 1000, 1200, and 1400 degreesC with times from 1 to 1000 h has been evaluated using the Rietveld analysis of neutron diffraction data. Results show that the yttria concentration of the as-sprayed tetragonal zirconia component generally decreased with increasing annealing temperature and time. As the yttria content in the tetragonal phase approached a limiting concentration, about 3.5 mol. % of YO1.5, the tetragonal phase transformed into monoclinic phase on cooling. An increase in monoclinic phase content was clearly observed after annealing for 24 h at 1400 degreesC and was nearly 35% after 100 h at 1400 degreesC. A similar trend was observed at 1200 degreesC for longer annealing times, with monoclinic phase formation beginning after 400 h. At 1000 degreesC, experimental times were not sufficient for monoclinic phase to form, although a decrease in the yttria concentration in the tetragonal phase was observed. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. Acad Sci Czech Republ, Inst Plasma Phys, Prague, Czech Republic. RP Ilavsky, J (reprint author), Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Ilavsky, Jan/D-4521-2013 OI Ilavsky, Jan/0000-0003-1982-8900 NR 14 TC 25 Z9 26 U1 3 U2 20 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 SEP PY 2001 VL 10 IS 3 BP 497 EP 501 DI 10.1361/105996301770349277 PG 5 WC Materials Science, Coatings & Films SC Materials Science GA 473TB UT WOS:000171063200024 ER PT J AU Powell, CJ Jablonski, A AF Powell, CJ Jablonski, A TI Influence of elastic-electron scattering on measurements of silicon dioxide film thicknesses by x-ray photoelectron spectroscopy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID MEAN FREE PATHS; ATTENUATION LENGTHS; ESCAPE PROBABILITY; OXIDIZED SILICON; 50-2000-EV RANGE; XPS; SIO2; AUGER; INTERFACES; METROLOGY AB We investigate the systematic error due to neglect of elastic scattering of photoelectrons in measurements of the thicknesses of thin films Of SiO2 on Si by x-ray photoelectron spectroscopy (XPS). Calculations were made of substrate Si 2p photoelectron currents excited by Mg and Al K alpha x rays for different SiO2 thicknesses, different angles of photoelectron emission, and three representative XPS configurations using an algorithm based on the transport approximation. We calculated practical effective attenuation lengths (EALs) from changes of the computed Si 2p photoelectron cur-rents. These EALs were less than the corresponding inelastic mean free paths by between 6.5% and 9.4%, with the difference depending on the x-ray source, the specific range of SiO2 film thicknesses under consideration, the XPS configuration, and the range of photoelectron emission angles. Useful average values of the EAL were found for emission angles between 0 degrees and about 60 degrees (with respect to the surface normal) and for silicon dioxide thicknesses such that the substrate signal was attenuated to not more than 1% and 10% of its original value. Our calculated EALs are in satisfactory agreement with measured EALs., For larger emission angles, the calculated EALs change rapidly with SiO2 thickness, and specific values should be found for the conditions of interest. (C) 2001 American Vacuum Society. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. Polish Acad Sci, Inst Phys Chem, PL-01224 Warsaw, Poland. RP Powell, CJ (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 38 TC 32 Z9 32 U1 2 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2001 VL 19 IS 5 BP 2604 EP 2611 DI 10.1116/1.1397463 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 478YP UT WOS:000171376700086 ER PT J AU Powell, CJ AF Powell, CJ TI Summary of the American society for testing and materials practice E 2108-00 for calibration of the electron binding-energy scale of an x-ray photoelectron spectrometer SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Powell, CJ (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. NR 4 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2001 VL 19 IS 5 BP 2689 EP 2690 DI 10.1116/1.1384560 PG 2 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 478YP UT WOS:000171376700098 ER PT J AU Lee, K AF Lee, K TI Global net community production estimated from the annual cycle of surface water total dissolved inorganic carbon SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID SUB-ARCTIC PACIFIC; SARGASSO SEA; ORGANIC-CARBON; DEEP-OCEAN; FLUX; SEAWATER; NITRATE; CO2; DISSOCIATION; TEMPERATURE AB Global net community production is determined, for the first time, from the decrease in salinity (S)-normalized total dissolved inorganic carbon (NCT = C-T x 35/S) inventory in the surface mixed layer corrected for changes due to net air-sea CO2 exchange and diffusive carbon flux from the upper thermocline. Changes in the mixed layer NCT inventory are estimated using a derived annual cycle of NCT and global records of the mixed layer depth. The annual NCT cycle is deduced from regional algorithms relating NCT to sea surface temperature (SST) and nitrate (NO3-), along with global records of seasonal mean SST and NO3-, and from the monthly mean surface partial pressure of CO2 and total alkalinity fields using thermodynamic models. The two methods show similar regional trends and yield global net community production estimates of 6.7 and 8.0 Gt C (1 Gt C = 1 x 10(12) kg carbon), respectively. The two global estimates are not significantly different and represent an 8-month period of 1990 (warming period) during which the mixed layer NCT concentration decreases. However, the estimates do not account for net community production during a 4-month cooling period. Ratios of net community production during the warming and cooling periods are estimated from multiyear sediment trap data at the Hawaii Ocean Time-series (22 degreesN, 158 degreesW) and Ocean Weather Station P (50 degreesN, 145 degreesW) sites. Global extrapolation of these ratios yields annual rates of net community production of 9.1 +/- 2.7 and 10.8 +/- 2.7 Gt C yr(-1). C1 Miami Univ, NOAA, Atlantic Oceanog & Meteorol Lab, Cooperat Inst Marine & Atmospher Study, Miami, FL 33149 USA. RP Lee, K (reprint author), Pohang Univ Sci & Technol, Sch Environm Sci & Engn, Nam Gu, San 31,Hyojadong, Pohang 790784, South Korea. RI Lee, Kitack/G-7184-2015 NR 39 TC 102 Z9 102 U1 0 U2 20 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 SEP PY 2001 VL 46 IS 6 BP 1287 EP 1297 PG 11 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 466PA UT WOS:000170652900004 ER PT J AU Rau, GH Ralston, S Southon, JR Chavez, FP AF Rau, GH Ralston, S Southon, JR Chavez, FP TI Upwelling and the condition and diet of juvenile rockfish: A study using (14)C, (13)C, and (15)N natural abundances SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID SHORTBELLY ROCKFISH; CENTRAL CALIFORNIA; MONTEREY BAY; RADIOCARBON; C-13/C-12; SEBASTES; FISH; ORGANISMS; N-15/N-14 AB Juvenile Sebastes jordani individuals sampled in late spring 1995, 1996, and 1997 near Monterey Bay, California, were analyzed for Delta (14)C, delta (13)C, and delta (15)N. As anticipated, a strong negative correlation was found between mean annual juvenile rockfish Delta (14)C and the preceding 3-month average Bakun upwelling index for this region. The sensitivity of this isotopic response by juvenile rockfish to upwelling variations was similar to that previously observed in surface-water inorganic carbon in nearby Half Moon Bay (Robinson 1981). This indicates that the Delta (14)C of surface-dwelling marine fish can be used as a measure of fish feeding in freshly upwelled (14)C-depleted water. However, we found no correlation between this parameter and fish somatic condition as measured by deviations in the regressions of individual fish (1) weight on length, (2) otolith size on fish length, or (3) total lipid content on dry weight. This questions the role upwelling plays in affecting juvenile rockfish condition. Also unrelated to fish condition were fish delta (13)C and delta (15)N, implying that the condition of juvenile S. jordani is unaffected by variation in the consumption of specific, isotopically discernible food resources. C1 Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA. Natl Marine Fisheries Serv, Santa Cruz, CA 95060 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. RP Rau, GH (reprint author), Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA. EM rau4@llnl.gov NR 28 TC 10 Z9 11 U1 1 U2 10 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 SEP PY 2001 VL 46 IS 6 BP 1565 EP 1570 PG 6 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 466PA UT WOS:000170652900029 ER PT J AU McGillis, WR Edson, JB Ware, JD Dacey, JWH Hare, JE Fairall, CW Wanninkhof, R AF McGillis, WR Edson, JB Ware, JD Dacey, JWH Hare, JE Fairall, CW Wanninkhof, R TI Carbon dioxide flux techniques performed during GasEx-98 SO MARINE CHEMISTRY LA English DT Article DE air-sea CO2 fluxes; direct covariance; profile method; deliberate tracers; CO2 sink; air-sea interactions; GasEx-98 ID SEA GAS-EXCHANGE; EDDY-CORRELATION; WIND-SPEED; AIR; CO2; OCEAN AB A comprehensive study of air-sea interactions focused on improving the quantification of CO2 fluxes and gas transfer velocities was performed within a large open ocean CO2 sink region in the North Atlantic. This study, GasEx-98, included shipboard measurements of direct covariance CO2 fluxes, atmospheric CO2 profiles, atmospheric DMS profiles, water column mass balances of CO2, and measurements of deliberate SF6-(3) He tracers, along with air-sea momentum, heat, and water vapor fluxes. The large air-sea differences in partial pressure of CO2 caused by a springtime algal bloom provided high signals for accurate CO2 flux measurements. Measurements were performed over a wind speed range of 1-16 m s(-1) during the three-week process study. This first comparison between the novel air-side and more conventional water column measurements of air-sea gas transfer show a general agreement between independent air-sea gas flux techniques. These new advances in open ocean air-sea gas flux measurements demonstrate the progress in the ability to quantify air-sea CO2 fluxes on short time scales. This capability will help improve the understanding of processes controlling the air-sea fluxes, which in turn will improve our ability to make regional and global CO2 flux estimates. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Woods Hole Oceanog Inst, Dept Appl Ocean Phys & Engn, Woods Hole, MA 02543 USA. Univ Colorado, CIRES, Boulder, CO 80303 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP McGillis, WR (reprint author), Woods Hole Oceanog Inst, Dept Appl Ocean Phys & Engn, Woods Hole, MA 02543 USA. NR 36 TC 97 Z9 99 U1 0 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD SEP PY 2001 VL 75 IS 4 BP 267 EP 280 DI 10.1016/S0304-4203(01)00042-1 PG 14 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 470CP UT WOS:000170853100002 ER PT J AU Aas, E Beyer, J Jonsson, G Reichert, WL Andersen, OK AF Aas, E Beyer, J Jonsson, G Reichert, WL Andersen, OK TI Evidence of uptake, biotransformation and DNA binding of polyaromatic hydrocarbons in Atlantic cod and corkwing wrasse caught in the vicinity of an aluminium works SO MARINE ENVIRONMENTAL RESEARCH LA English DT Article DE Atlantic cod; PAH; bile metabolites; CYP1A; DNA adducts; aluminium works ID FLOUNDER PLATICHTHYS-FLESUS; PERCH PERCA-FLUVIATILIS; MARINE FISH; CONTAMINATED SEDIMENTS; POLLUTED SEDIMENTS; HEPATIC-LESIONS; TOXIC-CHEMICALS; PUGET-SOUND; EXPOSURE; ADDUCTS AB Feral Atlantic cod (Gadus morhua) and corkwing wrasse (Symphodus melops) were investigated for polyaromatic hydrocarbon (PAH) contamination in the Karmsund strait, western Norway. This strait is highly contaminated with PAHs, and a main source is the chronic release of gas-scrubbing effluents from a local aluminium works. In both species, the level of biliary PAH metabolites and hepatic DNA adducts were higher in fish collected near the aluminium works. Interestingly, a significantly higher level of both biliary PAH metabolites and hepatic DNA adducts was found in corkwing wrasse as compared to cod, indicating a higher potential for genotoxic effects in this species. Hepatic cytochrome P4501A (CYP1A) in cod estimated by ethoxyresorufin-0-deethylase and an immunoassay technique (ELISA), seemed to be weakly induced at the contaminated sites. At the most contaminated site, skin ulcers and fin erosion were detected in about 70 and 45% of the cods, respectively. The data demonstrated that both cod and corkwing wrasse may be suitable target species for PAH pollution monitoring. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 RF Rogaland Res, N-4091 Stavanger, Norway. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Aas, E (reprint author), RF Rogaland Res, POB 2503 Ullandhaug, N-4091 Stavanger, Norway. RI Beyer, Jonny/E-8001-2011 NR 45 TC 69 Z9 75 U1 0 U2 22 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 SEP PY 2001 VL 52 IS 3 BP 213 EP 229 DI 10.1016/S0141-1136(00)00269-5 PG 17 WC Environmental Sciences; Marine & Freshwater Biology; Toxicology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Toxicology GA 470MJ UT WOS:000170875500002 PM 11570803 ER PT J AU Engel, DW Brouwer, M Mercaldo-Allen, R AF Engel, DW Brouwer, M Mercaldo-Allen, R TI Effects of molting and environmental factors on trace metal body-burdens and hemocyanin concentrations in the American lobster, Homarus americanus SO MARINE ENVIRONMENTAL RESEARCH LA English DT Article DE Homarus americanus; lobster; hemocyanin; copper; zinc; pollution; molt cycle ID CALLINECTES-SAPIDUS; COPPER-METALLOTHIONEINS; NEPHROPS-NORVEGICUS; BLUE-CRAB AB Hemocyanin concentrations in the hemolymph of marine crustacea are dependent on the molt cycle and on environmental conditions. Studies in our laboratories have found that hemocyanin levels in blue crabs are reduced after ecdysis and under conditions of environmental stress (Engel, Brouwer, & McKenna, 1993. Hemocyanin concentrations in marine crustaceans as a function of environmental conditions. Marine Ecology Progress Series, 93, 233-244). We have extended those studies to include the American lobster, Homarus americanus. Hemolymph and digestive gland tissues from Long Island Sound lobsters were analyzed for hemocyanin, copper, and zinc during different stages of the molt cycle. Hemocyanin, copper and zinc in the hemolymph were highest in premolt stages (D-1-D-4), and lowest in the postecdysal papershell stages (B-1-B-2). Concomitantly, copper in digestive glands decreased significantly following ecdysis, but no significant changes in the metals bound to metallothionein (MT) were observed. Copper-MT was the predominant form throughout the molt cycle, presumably because lobsters were obtained from copper-contaminated areas. To examine the effects of environmental factors, intermolt lobsters were collected front locations of different environmental quality along the Atlantic coast, and were analyzed for hemocyanin and trace metals. In general, animals from areas with a history or contamination showed the highest hemocyanin concentrations. Published by Elsevier Science Ltd. C1 NOAA, Natl Ocean Serv, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. Univ So Mississippi, Gulf Coast Res Lab, Ocean Springs, MS 39566 USA. NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Milford Lab, Milford, CT 06460 USA. RP Engel, DW (reprint author), NOAA, Natl Ocean Serv, Ctr Coastal Fisheries & Habitat Res, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 18 TC 29 Z9 37 U1 0 U2 9 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 SEP PY 2001 VL 52 IS 3 BP 257 EP 269 DI 10.1016/S0141-1136(01)00098-8 PG 13 WC Environmental Sciences; Marine & Freshwater Biology; Toxicology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Toxicology GA 470MJ UT WOS:000170875500005 PM 11570806 ER PT J AU Fields, E AF Fields, E TI Present and future status of the NOAA oceanographic fleet SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article AB NOAA's Office of Marine and Aviation Operations (OMAO) provides centralized management of NOAA's fleet of 15 vessels that support a wide range of operational and research missions. NOAA's ship requirements are being met with a mix of commercial charters, contracts for data, the UNOLS academic fleet and NOAA vessels. In 2000, OMAO developed its five-year strategic plan in direct support of the NOAA strategic plan. The primary focus of the OMAO strategic plan is to provide the best value in safe, high-quality ship and aircraft operations and scientific support to NOAA and the nation. Having efficient and effective ocean platforms that collect atmospheric and oceanographic data, which can ground truth (or validate) other data platforms, is still paramount to NOAA and the scientific community. As NOAA continues its critical research on the coupling of the atmosphere and ocean that drives global climate, as well as protecting and managing marine environments, its fleet will play a vital role in supporting these efforts. C1 NOAA, Off Marine & Aviat Operat, Silver Spring, MD 20910 USA. RP Fields, E (reprint author), NOAA, Off Marine & Aviat Operat, Silver Spring, MD 20910 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 USA SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD FAL PY 2001 VL 35 IS 3 BP 14 EP 17 PG 4 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 491WX UT WOS:000172134000004 ER PT J AU Hurley, DC Tewary, VK Richards, AJ AF Hurley, DC Tewary, VK Richards, AJ TI Surface acoustic wave methods to determine the anisotropic elastic properties of thin films SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE ultrasonic velocity; surface acoustic waves; elastic properties; laser ultrasonics; thin films ID FILTERED ARC EVAPORATION; BRILLOUIN-SCATTERING; INTERFERENCE-FRINGES; VELOCITY-MEASUREMENT; TIN FILMS; PHASE; CONSTANTS; LAYERS; INTERFEROMETER; ULTRASOUND AB We have developed experimental and analytical methods to measure the anisotropic elastic properties of thin supported films. In this approach, surface acoustic waves (SAWS) were generated using a line-focused laser. Waves with frequency components up to 400 MHz were detected by a Michelson interferometer. Dispersion relations for the SAW phase velocity were calculated from displacement waveforms acquired with source-detector separations of 5-15 mm. To determine film properties from the dispersion relations, we developed a new inversion algorithm based on the delta-function representation of the fully anisotropic, elastodynamic Green function for wave propagation. Our methods were first applied to an elastically isotropic aluminium film on an isotropic fused silica substrate. The results show the validity of our methods and were in good agreement with literature values. The results also illustrate various aspects of measurement uncertainty. The same SAW methods were used to examine a series of titanium nitride films on single-crystalline silicon wafers. The inversion results assuming orthotropic elastic symmetry indicated that c(11) increased and c(13) decreased with increasing film thickness. Values for the film thickness determined by our analysis were in good agreement with destructive measurements of the actual thicknesses. C1 Natl Inst Stand & Technol, Div Mat Reliabil, Boulder, CO 80305 USA. CSIRO, Lindfield, NSW 2070, Australia. RP Natl Inst Stand & Technol, Div Mat Reliabil, 325 Broadway, Boulder, CO 80305 USA. EM hurley@boulder.nist.gov NR 35 TC 44 Z9 45 U1 2 U2 19 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 SEP PY 2001 VL 12 IS 9 BP 1486 EP 1494 DI 10.1088/0957-0233/12/9/315 PG 9 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 478BX UT WOS:000171324000017 ER PT J AU Davydov, AV Kattner, UR Josell, D Blendell, JE Waterstrat, RM Shapiro, AJ Boettinger, WJ AF Davydov, AV Kattner, UR Josell, D Blendell, JE Waterstrat, RM Shapiro, AJ Boettinger, WJ TI Determination of the CoTi congruent melting point and thermodynamic reassessment of the Co-Ti system SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID PHASE-EQUILIBRIA; MODEL; TRANSITION; ELEMENTS; DIAGRAMS; ENTHALPY; METALS; COBALT; CO/TI AB New experimental results and a thermodynamic re-evaluation of the Co-Ti system are presented. Using differential thermal analysis (DTA) and a visual observation-of-melting (VOM) technique, the approximate to 220 K inconsistency in melting temperature in the literature for the B2 (CoTi) phase is resolved. The congruent melting point is determined to be 1776 +/- 5 K. The revised B2 melting temperature, along with other critically reviewed thermochemical and phase-equilibria data from the literature, are used to reassess the thermodynamic description of the Co-Ti system. As a result, a self-consistent set of optimized Gibbs-energy expressions for all CoTi phases is obtained. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Davydov, Albert/F-7773-2010 OI Davydov, Albert/0000-0003-4512-2311 NR 62 TC 25 Z9 25 U1 1 U2 18 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2001 VL 32 IS 9 BP 2175 EP 2186 DI 10.1007/s11661-001-0193-8 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 471HZ UT WOS:000170925100003 ER PT J AU Van Heerden, D Gavens, AJ Subramanian, PR Foecke, T Weihs, TP AF Van Heerden, D Gavens, AJ Subramanian, PR Foecke, T Weihs, TP TI The stability of Nb/Nb5Si3 microlaminates at high temperatures SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID INTERMETALLIC COMPOSITES; CREEP; NB; DEFORMATION; TOUGHNESS; SILICIDES; FRACTURE; BEHAVIOR; STRENGTH; ALLOYS AB The microstructural, phase, and chemical stability of Nb/Nb5Si3 microlaminates was investigated at temperatures ranging from 1200 degreesC to 1600 degreesC. Freestanding Nb/Nb5Si3 microlaminates were prepared by sputter deposition and their stability was investigated by annealing either in vacuum or in an Ar atmosphere. The microlaminates were generally structurally stable, with no evidence of layer pinchoff, even after annealing at 1600 degreesC. However, a small volume fraction (<2 pct) of voids formed in the silicide layers at 1500 degreesC and 1600 degreesC, which are attributed either to the Kirkendall diffusion of Si or to the growth of silicide grains. In terms of phase stability, there was no discernible dissolution of the Nb5Si3 layers and no silicide precipitates in the Nb layers following anneals at 1400 degreesC. Annealing at higher temperatures, though, resulted in the formation of non-equilibrium Nb3Si on the Nb/Nb5Si3 interfaces. This phase is thought to precipitate from the supersaturated Nb-Si solid solution on cooling, and is stabilized by the development of tensile stresses in the Nb layers. The most pervasive observed high-temperature breakdown mechanism was chemical in nature, namely, the loss of Si via sublimation to the environment. The Si loss was partially suppressed either by annealing in a Si-rich atmosphere or by annealing in Ar. C1 Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA. GE Co, Corp Res & Dev, Met Phys Lab, Schenectady, NY 12301 USA. NIST, Div Met, Gaithersburg, MD 20899 USA. Knolls Atom Power Lab, Schenectady, NY USA. RP Van Heerden, D (reprint author), Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA. RI Weihs, Timothy/A-3313-2010 NR 34 TC 10 Z9 11 U1 0 U2 7 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2001 VL 32 IS 9 BP 2363 EP 2371 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 471HZ UT WOS:000170925100020 ER PT J AU Meille, S Garboczi, EJ AF Meille, S Garboczi, EJ TI Linear elastic properties of 2D and 3D models of porous materials made from elongated objects SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID HASHIN-SHTRIKMAN BOUNDS; COMPOSITES; MODULI; POLYCRYSTALS; PLASTER; HOLES; MEDIA AB Porous materials are formed in nature and by man by many different processes. The nature of the pore space, which is usually the space left over as the solid backbone forms, is often controlled by the morphology of the solid backbone. In particular, sometimes the backbone is made from the random deposition of elongated crystals, which makes analytical techniques particularly difficult to apply. This paper discusses simple two- and three-dimensional porous models in which the solid backbone is formed by different random arrangements of elongated solid objects (bars/crystals). We use a general purpose elastic finite element routine designed for use on images of random porous composite materials to study the linear elastic properties of these models. Both Young's modulus and Poisson's ratio depend on the porosity and the morphology of the pore space, as well as on the properties of the individual solid phases. The models are random digital image models, so that the effects of statistical fluctuation, finite size effect and digital resolution error must be carefully quantified. It is shown how to average the numerical results over random crystal orientation properly. The relations between two and three dimensions are also explored, as most microstructural information comes from two-dimensional images, while most real materials and experiments are three dimensional. C1 INSA, GEMPPM Lab, F-63621 Villeurbanne, France. Lafarge LCR, F-38291 St Quentin Fallavier, France. Natl Inst Stand & Technol, Gaithersburg, MD 20878 USA. RP Meille, S (reprint author), INSA, GEMPPM Lab, 20 Ave Albert Einstein, F-63621 Villeurbanne, France. OI Meille, Sylvain/0000-0002-4553-1206 NR 28 TC 53 Z9 55 U1 2 U2 11 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 SEP PY 2001 VL 9 IS 5 BP 371 EP 390 DI 10.1088/0965-0393/9/5/303 PG 20 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 480PP UT WOS:000171470800003 ER PT J AU Panchapakesan, B DeVoe, DL Widmaier, MR Cavicchi, R Semancik, S AF Panchapakesan, B DeVoe, DL Widmaier, MR Cavicchi, R Semancik, S TI Nanoparticle engineering and control of tin oxide microstructures for chemical microsensor applications SO NANOTECHNOLOGY LA English DT Article; Proceedings Paper CT 8th Foresight Conference on Molecular Nanotechnology CY NOV 03-05, 2000 CL BETHESDA, MARYLAND ID SNO2 THIN-FILMS; GAS SENSORS; SENSITIVITY; DIOXIDE; POWDERS; MODEL; SOL AB The use of metal nanoparticles as seed layers for controlling the microstructures of tin oxide (SnO2) films on temperature controllable micromachined platforms has been investigated. The study is focused on SnO2 due to its importance in the field of chemical microsensors. Nanoparticle seeds of iron, cobalt, nickel, copper and silver were formed by vapour deposition on the microhotplates followed by annealing at 500 degreesC prior to self-aligned SnO2 deposition. Significant control of SnO2 grain sizes, ranging between 20 and 121 nm, was achieved depending on the seed-layer type. A correlation was found between decreasing the SnO2 grain size and increasing the melting temperature of the seed-layer metals, suggesting the use of high temperature metals as being appropriate choices as seed layers for obtaining a smaller SnO2 grain structure. Smaller grain diameters resulted in high sensitivity in 90 ppm ethanol illustrating the benefits of nanoparticle seeding for chemical sensing. The initial morphology, particle size and distribution of the seed layers was found to dictate the final SnO2 morphology and grain size. This paper not only demonstrates the possibility of depositing nanostructured oxide materials for chemical microsensor applications, but also demonstrates the feasibility of conducting combinatorial research into nanoparticle growth using temperature controllable microhotplate platforms. This paper also demonstrates the possibility of using multi-element arrays to form a range of different types of devices that could be used with suitable olfactory signal processing techniques in order to identify a variety of gases. C1 Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. Univ Maryland, Syst Res Inst, College Pk, MD 20742 USA. Hitachi Instruments Inc, Gaithersburg, MD 20899 USA. NIST, Proc Measurements Div, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Panchapakesan, B (reprint author), Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. RI DeVoe, Don/A-2891-2011 OI DeVoe, Don/0000-0002-7740-9993 NR 27 TC 71 Z9 72 U1 1 U2 17 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD SEP PY 2001 VL 12 IS 3 BP 336 EP 349 DI 10.1088/0957-4484/12/3/323 PG 14 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 480GR UT WOS:000171454100025 ER PT J AU Desrosiers, M Schauer, DA AF Desrosiers, M Schauer, DA TI Electron paramagnetic resonance (EPR) biodosimetry SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT Summer School on Advanced Topics in Radiation Dosimetry CY JUL 03-07, 2001 CL ATHENS, GREECE SP St Gobain Crystals & Detectors DE EPR biophysics; ionizing radiation; biodosimetry; bone; tooth ID TOOTH ENAMEL; SPIN-RESONANCE; RETROSPECTIVE DOSIMETRY; RADIATION-DOSIMETRY; ESR DOSIMETRY; BONE; RESIDENTS; EXPOSURE; ACCIDENT; REGION AB Radiation-induced electron paramagnetic resonance (EPR) signals were first reported by Gordy et al. [Proc. Nail. Acad. Sci. USA 41 (1955) 983]. The application of EPR spectroscopy to ionizing radiation dosimetry was later proposed by Brady et al. [Health Phys. 15 (1968) 43]. Since that time EPR dosimetry has been applied to accident and epidemiologic dose reconstruction, radiation therapy. food irradiation, quality assurance programs and archaeological dating. Materials that have been studied include bone, tooth enamel, alanine and quartz. This review paper presents the fundamentals and applications of EPR biodosimetry. Detailed information regarding sample collection and preparation. EPR measurements, dose reconstruction. and data analysis and interpretation will be reviewed for tooth enamel. Examples of EPR biodosimetry application in accidental overexposures, radiopharmaceutical dose assessment and retrospective epidemiologic studies will also be presented. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Uniformed Serv Univ Hlth Sci, Dept Radiol & Nucl Med, Bethesda, MD 20814 USA. Natl Inst Stand & Technol, Ionizing Radiat Div, Bethesda, MD 20889 USA. RP Schauer, DA (reprint author), Uniformed Serv Univ Hlth Sci, Dept Radiol & Nucl Med, 4301 Jones Bridge Rd, Bethesda, MD 20814 USA. NR 51 TC 44 Z9 45 U1 0 U2 7 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 SEP PY 2001 VL 184 IS 1-2 BP 219 EP 228 DI 10.1016/S0168-583X(01)00614-0 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 478HN UT WOS:000171341100012 ER PT J AU Licandro, P Conversi, A Ibanez, F Jossi, J AF Licandro, P Conversi, A Ibanez, F Jossi, J TI Time series analysis of interrupted long-term data set (1961-1991) of zooplankton abundance in Gulf of Maine (northern Atlantic, USA) SO OCEANOLOGICA ACTA LA English DT Article DE Calanus finmarchicus; Gulf of Maine; missing data; time series analysis; zooplankton ID PLANKTON RECORDER SURVEY; SHELF ECOSYSTEM; FINMARCHICUS; ENVIRONMENT; REGIONS; CALANUS AB The main interannual and seasonal signals have been extracted from a multi-decadal data set of zooplankton collected with the Continuous Plankton Recorder in the Gulf of Maine, from January 1961 to December 1991. The monthly abundances of seven species or genera of copepods representing the dominant biomass in the area were considered. The presence of a large consecutive gap (35 months) prevented the use of statistical methods for the prediction of missing data. The eigen-vector filtering (EVF) method was then used on the original time series, while retaining the missing values. For each zooplankton taxon, two principal modes of variability (F-1 and F-2) were extracted, representing the interannual and seasonal variations, respectively. Results of EVF allowed the classification of the different genera or species, according to their main type of variability, into taxa 'interannually dominated' (C finmarchicus, Metridia lucens, Oithona spp.), 'seasonally dominated' (Centropages typicus), and taxa characterized by both 'interannual and seasonal variation' (Pseudocalanus spp., Temora longicornis, Acartia spp.). A comparison between the interannual trends of 'interannually dominated species' and sea surface temperature (SST) indicated that all the species were more or less correlated with this important environmental factor. In particular, a strong negative correlation was found between C finmarchicus and SST at a lag of about 0 months, showing that lower values of SST correspond to higher abundances of Calanus finmarchicus at this latitude. (C) 2001 Ifremer/CNRS/IRD/Editions scientifiques et medicales Elsevier SAS. C1 Lab Oceanog Biol & Ecol Plancton Marin, ESA 7076, F-06230 Villefranche Sur Mer, France. SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. US Dept Commerce, NOAA, Narragansett, RI 02882 USA. RP Licandro, P (reprint author), Stag Zool Anto Dohrn, Villa Comunale, I-80121 Naples, Italy. NR 36 TC 17 Z9 19 U1 0 U2 8 PU GAUTHIER-VILLARS/EDITIONS ELSEVIER PI PARIS PA 23 RUE LINOIS, 75015 PARIS, FRANCE SN 0399-1784 J9 OCEANOL ACTA JI Oceanol. Acta PD SEP-OCT PY 2001 VL 24 IS 5 BP 453 EP 466 DI 10.1016/S0399-1784(01)01169-0 PG 14 WC Oceanography SC Oceanography GA 490UP UT WOS:000172070800008 ER PT J AU Schwartz, MD Crawford, TM AF Schwartz, MD Crawford, TM TI Detecting energy balance modifications at the onset of spring SO PHYSICAL GEOGRAPHY LA English DT Article DE phenology; spring; energy balance; North America ID DAILY TEMPERATURE RANGES; DECIDUOUS FOREST; GREEN-WAVE; PHENOLOGY; VARIABILITY; MODEL; RESISTANCE; LENGTH; IMPACT AB The nature of energy-flux transitions during the onset of midlatitude spring has not been widely examined, despite their critical implications for global-scale biospheric measures and climate change. Further conventional assessment of these phenomena across multiple locations is restricted by satellite-derived data limitations, and the paucity of surface measurement sites. In this paper, we explore a new phenology-based strategy for evaluating the spring surface energy-balance shift that can address these concerns. Our technique can reflect native-species responses and atmospheric surface layer change at a variety of sites, using synoptic-scale first leaf and first bloom phenology models. We test the approach at three locations with diverse climates, and within a group of stations in the state of Oklahoma, which has moderate climate variations across an east-to-west gradient. The results show that the onset of spring in midlatitudes is a modally abrupt (rather than gradual) seasonal transition in terms of energy balance (sensible and latent heat levels) and carbon-flux change that can be linked directly to vegetation phenology. The consistent temporal pattern and magnitude of flux variations across diverse sites suggest that this technique has potential as a proxy for spring energy-balance change at many locations. C1 Univ Wisconsin, Dept Geog, Milwaukee, WI 53201 USA. Univ Oklahoma, Natl Severe Storms Lab, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73069 USA. RP Schwartz, MD (reprint author), Univ Wisconsin, Dept Geog, POB 413, Milwaukee, WI 53201 USA. NR 32 TC 27 Z9 31 U1 0 U2 7 PU V H WINSTON & SON INC PI PALM BEACH PA 360 SOUTH OCEAN BLVD, PH-B, PALM BEACH, FL 33480 USA SN 0272-3646 J9 PHYS GEOGR JI Phys. Geogr. PD SEP-OCT PY 2001 VL 22 IS 5 BP 394 EP 409 PG 16 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Physical Geography; Geology; Meteorology & Atmospheric Sciences GA 556WF UT WOS:000175871400003 ER PT J AU Bohm, S Schippers, S Shi, W Muller, A Djuric, N Dunn, GH Zong, W Jelenkovic, B Danared, H Eklow, N Glans, P Schuch, R AF Bohm, S Schippers, S Shi, W Muller, A Djuric, N Dunn, GH Zong, W Jelenkovic, B Danared, H Eklow, N Glans, P Schuch, R TI Influence of electromagnetic fields on the dielectronic recombination of Ne7+ ions SO PHYSICAL REVIEW A LA English DT Article ID MAGNETIC-FIELDS AB The influence of crossed electric and magnetic fields on dielectronic recombination of Ne7+ ions has been measured at the Stockholm heavy-ion storage ring CRYRING. The electron energy range covered all dielectronic recombination resonances attached to 2s --> 2p(1/2) and 2s --> 2p(3/2) Deltan=0 core excitations, Two sets of measurements at magnetic fields of 180 mT and 30 mT have been per-formed. For the measurement at 180 mT we applied 25 different electric fields between 0 and 1400 V/cm. The resonance strength for dielectronic recombination via high Rydberg states initially increases linearly with electric field and later levels out. At a magnetic field of 30 mT we applied 15 different electric fields ranging from 0 to 140 V/cm. Compared to the measurement at 180 mT the initial slope of the rate enhancement was larger by almost a factor of 2. The fraction of resonant strength not measured due to field ionization is estimated by a model calculation of dielectronic recombination cross sections. C1 Univ Giessen, Inst Kernphys, D-35392 Giessen, Germany. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Inst Phys, YU-10800 Belgrade, Yugoslavia. Manne Siegbahn Lab, S-10405 Stockholm, Sweden. Stockholm Univ, S-10405 Stockholm, Sweden. RP Bohm, S (reprint author), Univ Giessen, Inst Kernphys, D-35392 Giessen, Germany. RI Schippers, Stefan/A-7786-2008; Muller, Alfred/A-3548-2009 OI Schippers, Stefan/0000-0002-6166-7138; Muller, Alfred/0000-0002-0030-6929 NR 17 TC 13 Z9 13 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 SEP PY 2001 VL 64 IS 3 AR 032707 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 472HT UT WOS:000170978600052 ER PT J AU Curtis, EA Oates, CW Hollberg, L AF Curtis, EA Oates, CW Hollberg, L TI Quenched narrow-line laser cooling of Ca-40 to near the photon recoil limit SO PHYSICAL REVIEW A LA English DT Article ID ATOMS; SPECTROSCOPY; STRONTIUM; CALCIUM; ENERGY AB We present a cooling method that should be generally applicable to atoms with narrow optical transitions. This technique uses velocity-selective pulses to drive atoms towards a zero-velocity dark state and then quenches the excited state to increase the cooling rate. We demonstrate this technique of quenched narrow-line cooling by reducing the 1D temperature of a sample of neutral Ca-40 atoms. We cool selected velocities with the S-1(0)(4s(2)) --> P-3(1) (4s4p) 657-nm intercombination line and quench with the P-3(1)(4s4p) --> S-1(0)(4s5s) intercombination line at 553 nm, which increases the cooling rate eightfold. Limited only by available quenching laser power, we have transferred 18% of the atoms from our initial 2-mK velocity distribution and achieved temperatures as low as 4 muK, corresponding to a v(rms) of 2.8 cm/s or 2 recoils at 657 nm. This cooling technique, which is closely related to Raman cooling, can be extended to three dimensions. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80305 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Curtis, EA (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, 325 Broadway, Boulder, CO 80305 USA. NR 17 TC 59 Z9 59 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 2001 VL 64 IS 3 AR 031403 DI 10.1103/PhysRevA.64.031403 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 472HT UT WOS:000170978600007 ER PT J AU Fatemi, F Jones, KM Wang, H Walmsley, I Lett, PD AF Fatemi, F Jones, KM Wang, H Walmsley, I Lett, PD TI Dynamics of photoinduced collisions of cold atoms probed with picosecond laser pulses SO PHYSICAL REVIEW A LA English DT Article ID PHOTOASSOCIATIVE SPECTROSCOPY; ULTRACOLD COLLISIONS; 2-COLOR PHOTOASSOCIATION; EXCITED-STATES; REAL-TIME; IONIZATION; MOLECULES; NA-2; DISTRIBUTIONS; SODIUM AB Pump-probe experiments are performed in which cold colliding Na atoms are photoassociated to form Na-2. molecules, and subsequently ionized. The experiments are performed in a regime where the pulsed photoassociation to an intermediate potential takes place at long range, and to several electronic, vibrational, and rotational states. A probe pulse then produces an ionization signal by further exciting these molecules to autoionizing doubly excited states. The time dependence of the ion signal shows a dramatic flux-enhancement effect on a nanosecond time scale due to the motion on the intermediate potentials. This time dependence can be viewed as monitoring the inward motion and dephasing of a population wave packet formed at long range. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Williams Coll, Dept Phys, Williamstown, MA 01267 USA. Aerospace Corp, Elect & Photon Lab, El Segundo, CA 90245 USA. Univ Rochester, Inst Opt, Rochester, NY 14627 USA. RP Fatemi, F (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. NR 34 TC 26 Z9 26 U1 1 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 SEP PY 2001 VL 64 IS 3 AR 033421 DI 10.1103/PhysRevA.64.033421 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 472HT UT WOS:000170978600089 ER PT J AU Hood, CJ Kimble, HJ Ye, J AF Hood, CJ Kimble, HJ Ye, J TI Characterization of high-finesse mirrors: Loss, phase shifts, and mode structure in an optical cavity SO PHYSICAL REVIEW A LA English DT Article ID SINGLE ATOMS; PHOTONS; LASER AB An extensive characterization of high-finesse optical cavities used in cavity QED experiments is described. Different techniques in the measurement of the loss and phase shifts associated with the mirror coatings are discussed and their agreement shown. Issues of cavity-field mode structure supported by the dielectric coatings are related to our effort to achieve the strongest possible coupling between an atom and the cavity. C1 CALTECH, Norman Bridge Lab Phys 12 33, Pasadena, CA 91125 USA. Univ Colorado, Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. RP Hood, CJ (reprint author), CALTECH, Norman Bridge Lab Phys 12 33, Pasadena, CA 91125 USA. RI Ye, Jun/C-3312-2011 NR 17 TC 104 Z9 108 U1 2 U2 12 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 SEP PY 2001 VL 64 IS 3 AR 033804 DI 10.1103/PhysRevA.64.033804 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 472HT UT WOS:000170978600110 ER PT J AU Kim, YK AF Kim, YK TI Scaling of plane-wave Born cross sections for electron-impact excitation of neutral atoms SO PHYSICAL REVIEW A LA English DT Article ID CLOSE-COUPLING CALCULATIONS; ALKALI-METAL ATOMS; INELASTIC-COLLISIONS; RESONANCE LINES; SCATTERING; HELIUM; TRANSITION; LITHIUM; MERCURY; IONS AB Two methods to scale plane-wave Born cross sections for electron-impact excitations of neutral atoms are shown to produce excitation cross sections comparable in accuracy to those obtained by more sophisticated collision theories such as the convergent close-coupling method. These scaling methods are applicable to integrated cross sections for electric dipole-allowed transitions. Scaled cross sections are in excellent agreement with available theoretical and experimental data for excitations in H, He, Li, Be, Na, Mg, K, Ca, Rb, Sr, Cs, Ba, Hg, and Tl, indicating the possibility of rapid and reliable calculations of excitation cross sections for many other neutral atoms. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kim, YK (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 43 TC 75 Z9 75 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 SEP PY 2001 VL 64 IS 3 AR 032713 DI 10.1103/PhysRevA.64.032713 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 472HT UT WOS:000170978600058 ER PT J AU Machholm, M Julienne, PS Suominen, KA AF Machholm, M Julienne, PS Suominen, KA TI Calculations of collisions between cold alkaline-earth-metal atoms in a weak laser field SO PHYSICAL REVIEW A LA English DT Article ID OPTICAL FREQUENCY STANDARD; PHOTOASSOCIATION SPECTROSCOPY; ULTRACOLD COLLISIONS; ELECTRONIC-STRUCTURE; SCATTERING LENGTHS; DIATOMIC-MOLECULES; COOLED ATOMS; NOBLE-GASES; LINE-SHAPES; SR ATOMS AB We calculate the fight-induced collisional loss of laser-cooled and trapped magnesium atoms for detunings up to 50 atomic linewidths to the red of the S-1(0)-P-1(1) cooling transition. We evaluate loss rate coefficients due to both radiative and nonradiative state-changing mechanisms for temperatures at and below the Doppler-cooling temperature. We solve the Schrodinger equation with a complex potential to represent spontaneous decay, but also give analytic models for various limits. Vibrational structure due to molecular photoassociation is pre-sent in the trap loss spectrum. Relatively broad structure due to absorption to the Mg-2 (1)Sigma (u) state occurs for detunings larger than about ten atomic linewidths. A much sharper structure, especially evident at low temperature, occurs even at smaller detunings due to Mg-2 (1)Pi (g) absorption, which is weakly allowed due to relativistic retardation corrections to the forbidden dipole transition strength. We also perform model studies for the other alkaline-earth-metal species Ca, Sr, and Ba, and for Yb, and we find similar qualitative behavior as for Mg. C1 Natl Univ Singapore, Dept Computat Sci, Singapore 119260, Singapore. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Turku Univ, Dept Appl Phys, FIN-20014 Turun Yliopisto, Finland. Helsinki Inst Phys, FIN-00014 Helsingin Yliopisto, Finland. Univ Copenhagen, NBIfAFG, Orsted Lab, DK-2100 Copenhagen O, Denmark. RP Machholm, M (reprint author), Natl Univ Singapore, Dept Computat Sci, Singapore 119260, Singapore. 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 52 TC 47 Z9 49 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 SEP PY 2001 VL 64 IS 3 AR 033425 DI 10.1103/PhysRevA.64.033425 PG 19 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 472HT UT WOS:000170978600093 ER PT J AU Payne, MG Deng, L AF Payne, MG Deng, L TI Extremely slow propagation of a light pulse in an ultracold atomic vapor: A Raman scheme without electromagnetically induced transparency SO PHYSICAL REVIEW A LA English DT Article ID GAIN AB We describe a Raman scheme where the group velocity of an optical pulse can be altered dramatically. With this none electromagnetically-induced-transparency scheme, we show that when on a two-photon resonance, a light pulse can propagate with extremely slow group velocity. Both pulse narrowing and broadening can occur depending upon the choice of two-photon detuning. When using a tuned far-off two-photon resonance, we show that the pulse propagates "superluminally" in the medium with pulse narrowing. C1 Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. NIST, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RP Payne, MG (reprint author), Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. RI Deng, Lu/B-3997-2012 NR 13 TC 48 Z9 49 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 2001 VL 64 IS 3 AR 031802 DI 10.1103/PhysRevA.64.031802 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 472HT UT WOS:000170978600013 ER PT J AU Bourdarot, F Lynn, JW Baggio-Saitovitch, E Huang, Q Sanchez, DR Skanthakumar, S AF Bourdarot, F Lynn, JW Baggio-Saitovitch, E Huang, Q Sanchez, DR Skanthakumar, S TI Magnetic behavior of the rare-earth compounds RNiBC by neutron scattering SO PHYSICAL REVIEW B LA English DT Article ID MOSSBAUER-SPECTROSCOPY; CRYSTAL-STRUCTURE; SUPERCONDUCTIVITY; ORDER; YBNIBC; HONIBC; IONS AB Neutron diffraction and small angle neutron scattering measurements have been carried out on RNiBC (R=Er, Th, Dy) to investigate the crystallography, magnetic correlations, and long range magnetic ordering. Crystallographic refinements show a strong boron-carbon and nickel-carbon bonding similar to RNiZB2C, but the rare-earth-carbon plane exhibits a buckling which does not exist in the RNi2B2C series. The magnetism in the RNiBC series is quite simple, with a magnetic moment direction going from the a-b plane to the c axis as the atomic number of the rare-earth increases. Er becomes ferromagnetic at T-C= 4.6 K, with a saturated moment of 7.2 mu (B) along the c axis. Th orders ferromagnetically at T-C= 15 K. Below 12.5 K an incommensurate modulation develops with a modulation wave vector of (0 0 1/8), as well as an antiferromagnetic component with k= (0 0 1/2). The moments, which vary in both magnitude and direction, are in the a-b plane with an average value of 7.79 mu (B). DyNiBC exhibits the same behavior, with a T-C and T-N of 17.5 and 13.5 K, respectively. C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. CEA Grenoble, SPSMS,MDN, Dept Rech Fondamentale Mat Condensee, F-38054 Grenoble 9, France. Ctr Brasileiro Pesquisas Fis, BR-22290180 Rio De Janeiro, Brazil. Univ Maryland, College Pk, MD 20742 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Bourdarot, F (reprint author), NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Candela, Dalber/G-3636-2012; Saitovitch, Elisa/A-6769-2015 NR 22 TC 7 Z9 7 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 2001 VL 64 IS 10 AR 104410 DI 10.1103/PhysRevB.64.104410 PG 12 WC Physics, Condensed Matter SC Physics GA 472HQ UT WOS:000170978400047 ER PT J AU Fitzsimmons, MR Leighton, C Hoffmann, A Yashar, PC Nogues, J Liu, K Majkrzak, CF Dura, JA Fritzsche, H Schuller, IK AF Fitzsimmons, MR Leighton, C Hoffmann, A Yashar, PC Nogues, J Liu, K Majkrzak, CF Dura, JA Fritzsche, H Schuller, IK TI Influence of interfacial disorder and temperature on magnetization reversal in exchange-coupled bilayers SO PHYSICAL REVIEW B LA English DT Article ID UNIDIRECTIONAL ANISOTROPY; THIN-FILMS; BIAS; SYSTEMS; MODEL; MULTILAYERS; DEPENDENCE; COERCIVITY; STATE AB Polarized neutron reflectometry is used to measure the thermal response of the net-magnetization vector of polycrystalline ferromagnetic (F) Fe films exchange coupled to twinned (110) MnF2 antiferromagnetic (AF) layers. We observe a strong correlation between the temperature dependencies of the net sample magnetization perpendicular to the applied field at coercivity and exchange bias. For cooling field and measurement conditions involving magnetization reversal via rotation, we find a range of temperature dependencies. For the smoothest F-AF interface, the temperature dependence of exchange bias compares well to a S=5/2 Brillouin function-an observation predicted by some theoretical models. This temperature dependence is expected for the sublattice magnetization and,the square root of the anisotropy constant rootK(1) of bulk MnF2. In contrast, for a rough F-A-F interface the magnetization reversal process (and exchange bias) showed little temperature dependence up to temperatures approaching the AF Neel point-a clear consequence of increasing interfacial disorder in a F-AF epitaxial system. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Autonoma Barcelona, Dept Fis, Bellaterra 08193, Spain. NIST, Gaithersburg, MD 20899 USA. Hahn Meitner Inst Kernforsch Berlin GmbH, D-1000 Berlin, Germany. RP Leighton, C (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Dura, Joseph/B-8452-2008; Liu, Kai/B-1163-2008; Nogues, Josep/D-7791-2012; Lujan Center, LANL/G-4896-2012; Hoffmann, Axel/A-8152-2009; OI Dura, Joseph/0000-0001-6877-959X; Liu, Kai/0000-0001-9413-6782; Nogues, Josep/0000-0003-4616-1371; Hoffmann, Axel/0000-0002-1808-2767; Fritzsche, Helmut/0000-0001-5288-8302 NR 40 TC 25 Z9 25 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 SEP 1 PY 2001 VL 64 IS 10 AR 104415 DI 10.1103/PhysRevB.64.104415 PG 5 WC Physics, Condensed Matter SC Physics GA 472HQ UT WOS:000170978400052 ER PT J AU Stiles, MD Halilov, SV Hyman, RA Zangwill, A AF Stiles, MD Halilov, SV Hyman, RA Zangwill, A TI Spin-other-orbit interaction and magnetocrystalline anisotropy SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-FUNCTIONAL THEORY; MAGNETIC-ANISOTROPY; ENERGY; METALS; POLARIZATION; SYSTEMS; COBALT; FE; CO; NI AB We report the effect of the two-body, spin-other-orbit interaction on the magnetocrystalline anisotropy energy of the 3 d transition metals. The relevant energy differences were computed for bee Fe, fee Ni, and hep Co using a linearized augmented plane-wave method to solve the scalar relativistic Kohn-Sham equations in the local spin-density approximation. The spin-other-orbit interaction was incorporated at the level of the Hartree approximation. Special care was taken to guarantee the correctness of our numerical procedures. We find that the spin-other-orbit interaction does indeed change the anisotropy energy, but the effect is too small to account for the disagreement with experiment found in previous calculations for all three elements. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. De Paul Univ, Dept Phys, Chicago, IL 60614 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 38 TC 27 Z9 27 U1 1 U2 10 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 SEP 1 PY 2001 VL 64 IS 10 AR 104430 DI 10.1103/PhysRevB.64.104430 PG 7 WC Physics, Condensed Matter SC Physics GA 472HQ UT WOS:000170978400067 ER PT J AU Shim, Y Landau, DP AF Shim, Y Landau, DP TI Dynamic finite-size scaling of the normalized height distribution in kinetic surface roughening SO PHYSICAL REVIEW E LA English DT Article ID MOLECULAR-BEAM EPITAXY; DIRECTED POLYMERS; GROWTH-MODELS; 2+1 DIMENSIONS; NONEQUILIBRIUM GROWTH; RANDOM-MEDIA; INSTABILITY; INTERFACES; UNIVERSALITY; DIFFUSION AB Using well-known simple growth models, we have studied the dynamic finite-size scaling theory for the normalized height distribution of a growing surface. We find a simple functional form that explains size-dependent behavior of the skewness and kurtosis in the transient regime, and obtain the transient- and longtime values of the skewness and kurtosis for the models. Scaled distributions of the models are obtained, and the shape of each distribution is discussed in terms of the interfacial width, skewness, and kurtosis, and compared with those for other models. Exponents eta (+) and eta (-), which characterize the form of the distribution, are determined from an exponential fitting of scaling functions. Our detailed results reveal that eta (+) + eta (-) approximate to 4 for a model obeying usual scaling in contrast to eta (+) + eta (-) <4 with (-) = 1 for a model exhibiting anomalous scaling as well as multiscaling. Since we obtain eta (+) + eta (-) approximate to 4 for a model exhibiting anomalous scaling but no multiscaling, we conclude that the deviation from eta (+) + eta (-) approximate to 4 is due to the presence of multiscaling behavior in a model. C1 Univ Georgia, Ctr Simulat Phys, Athens, GA 30602 USA. RP Shim, Y (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. EM yunsic.shim@nist.gov NR 55 TC 13 Z9 13 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD SEP PY 2001 VL 64 IS 3 AR 036110 DI 10.1103/PhysRevE.64.036110 PN 2 PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 474ZD UT WOS:000171136400024 PM 11580397 ER PT J AU Scott, RB AF Scott, RB TI Evolution of energy and enstrophy containing scales in decaying, two-dimensional turbulence with friction SO PHYSICS OF FLUIDS LA English DT Article AB Decaying, two-dimensional (2D), isotropic, incompressible, turbulence with finite Newtonian (lateral) friction and linear bottom drag is examined analytically. The classical result for inviscid, 2D turbulence of an upscale transfer of energy is shown to be robust to the presence of certain types of friction. It is shown that the energy-weighted mean wave number decreases with time, regardless of the Newtonian viscosity (i.e., for all Reynolds number) or linear bottom drag coefficients. For a given flow state, the time rate of change of the energy-weighted mean wave number is shown to be independent of the bottom friction but to increase with the Newtonian viscosity and the rate of spreading of energy in wave number space. There is an implicit dependence upon bottom friction since the second time derivative of the energy-weighted mean wave number involves a term linear in bottom drag coefficient. The forward transfer of enstrophy, on the other hand, is counter-balanced by the enstrophy decay due to finite Newtonian friction. The enstrophy-weighted mean wavelength decreases for sufficiently large Reynolds number, but increases when the Reynolds number becomes small enough. For a given flow state, the first time derivative of the enstrophy-weighted mean wavelength is independent of bottom friction. However, it implicitly affects the evolution through its influence upon the rate of spreading. (C) 2001 American Institute of Physics. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Scott, RB (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, POB CN710,Sayre Hall, Princeton, NJ 08544 USA. RI Scott, Robert/B-9876-2008 NR 14 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD SEP PY 2001 VL 13 IS 9 BP 2739 EP 2742 DI 10.1063/1.1388181 PG 4 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 463QP UT WOS:000170489000032 ER PT J AU Sieck, LW Buckley, TJ Herron, JT Green, DS AF Sieck, LW Buckley, TJ Herron, JT Green, DS TI Pulsed electron-beam ionization of humid air and humid air/toluene mixtures: Time-resolved cationic kinetics and comparisons with predictive models SO PLASMA CHEMISTRY AND PLASMA PROCESSING LA English DT Article DE plasma; electron beam; kinetics; ionic reactions; cluster ions; air; toluene; mass spectrometry; database ID GAS-PHASE ION; ATMOSPHERIC OZONE; THERMOCHEMISTRY; MOLECULES; CHEMISTRY AB The technique of pulsed electron-beam high-pressure mass spectrometry was used to investigate the sequential cationic chemistry in humid air streams at 4.2 x 10(2) Pa and 380 K. The system was then modeled using the ACUCHEM program, incorporating thirty-five reactions taken from the formulations given in Part I of the new National Institute of Standards and Technology (NIST) Chemical Kinetics Database for Humid Air Plasmas. The resulting temporal ion profiles were found to be in qualitative agreement with the laboratory data. Analogous pulsed elect,on-beam measurements were also carried out with humid ab samples containing low levels of toluene, and these results were also reproduced qualitatively by a model incorporating forty-eight reactions after the inclusion of an unexpected, but crucial, channel involving the reaction of an intermediate air-generated cluster ion with toluene. The benefits of laboratory validation of predictive databases in systems for which the literature data are incomplete are emphasized. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Univ Maryland, Syst Res Inst, College Pk, MD 20742 USA. NR 17 TC 12 Z9 12 U1 2 U2 9 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0272-4324 J9 PLASMA CHEM PLASMA P JI Plasma Chem. Plasma Process. PD SEP PY 2001 VL 21 IS 3 BP 441 EP 457 DI 10.1023/A:1011030627752 PG 17 WC Engineering, Chemical; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA 449WK UT WOS:000169710000009 ER PT J AU Herron, JT Green, DS AF Herron, JT Green, DS TI Chemical kinetics database and predictive schemes for nonthermal humid air plasma chemistry. Part II. Neutral species reactions SO PLASMA CHEMISTRY AND PLASMA PROCESSING LA English DT Article DE plasma; discharge; electron-beam; database; kinetic; thermodynamic; rate constant; humid air; bimolecular ID THERMAL UNIMOLECULAR REACTIONS; COLLISION RATE CONSTANTS; FALL-OFF RANGE; ATMOSPHERIC CHEMISTRY; IUPAC SUBCOMMITTEE; PHOTOCHEMICAL DATA; LOW-PRESSURES; GAS-PHASE; DATA-BASE; COMBUSTION AB Reliable kinetics data a, e necessary input for models describing the decomposition of gases in electric discharge of electron-beam devices. In this second part of a continuing ser ies, we provide a core database describing the dominant reactions of neutral species in nonthermal low temperature (300-700K) pulsed plasmas containing humid ail. Recommended rate constants and extrapolation methods are provided in a manner to facilitate prediction of reactivities as a function of temperature and pressure. C1 NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Univ Maryland, Syst Res Inst, College Pk, MD 20742 USA. RP Herron, JT (reprint author), NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 52 TC 117 Z9 120 U1 3 U2 31 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0272-4324 J9 PLASMA CHEM PLASMA P JI Plasma Chem. Plasma Process. PD SEP PY 2001 VL 21 IS 3 BP 459 EP 481 DI 10.1023/A:1011082611822 PG 23 WC Engineering, Chemical; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA 449WK UT WOS:000169710000010 ER PT J AU White, CC Migler, KB Wu, WL AF White, CC Migler, KB Wu, WL TI Measuring T-g in ultra-thin polymer films with an excimer fluorescence technique SO POLYMER ENGINEERING AND SCIENCE LA English DT Article ID GLASS-TRANSITION TEMPERATURE; PROBE; RELAXATION; INTERFACE; DIFFUSION; MOBILITY; MONOMER AB An excimer fluorescence technique has been applied to the measurement of T-g of ultra-thin polystyrene films. This technique utilizes an excimer-forming molecule with fluorescent emission in two wavelength bands. The intensity ratio of these bands is a sensitive measure of local viscosity. This technique has been applied to five polystyrene films in the thickness range of 25 nm to 200 nm supported on quartz substrates. The observed T-g for the five ultra-thin polymer films was similar to the bulk T-g with no observed dependence upon thickness. Additionally, the T-g determined for each film did not show any dependence upon thermal history. C1 Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. RP White, CC (reprint author), Natl Inst Stand & Technol, Div Polymer, Gaithersburg, MD 20899 USA. NR 26 TC 12 Z9 12 U1 0 U2 6 PU SOC PLASTICS ENG INC PI BROOKFIELD PA 14 FAIRFIELD DR, BROOKFIELD, CT 06804-0403 USA SN 0032-3888 J9 POLYM ENG SCI JI Polym. Eng. Sci. PD SEP PY 2001 VL 41 IS 9 BP 1497 EP 1505 DI 10.1002/pen.10848 PG 9 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 479XK UT WOS:000171429000004 ER PT J AU Wong-Ng, W Kaduk, JA Dillingham, J AF Wong-Ng, W Kaduk, JA Dillingham, J TI Crystallographic studies and X-ray diffraction patterns of Ba5R8Zn4O21 by Rietveld refinements SO POWDER DIFFRACTION LA English DT Article ID BOND-VALENCE PARAMETERS; BA-CU-O; CRYSTAL-STRUCTURE; OXIDES; SUPERCONDUCTOR; ZINC; ND; DY; HO; ER AB The structure of the Ba5R8Zn4O21 series (R=lanthanides) was investigated using X-ray Rietveld refinements. The compounds were successfully prepared for R=Eu, Gd, Dy, Ho, Er, Tm, and Yb. Ba5R8Zn4O21 crystallizes in the tetragonal space group I4/m; for R=Yb to Eu, a ranges from 13.635 02(5) to 13.960 62(9) Angstrom, c from 5.658 46(3) to 5.784 83(5) Angstrom, and V from 1051.987(8) to 1127.459(14) Angstrom (3). The Zn2+ ions adopt a fivefold distorted square pyramidal coordination. The seven-coordinate R3+ reside in monocapped trigonal prisms. These prisms share edges, and form layers stacked along the c axis. There are two types of BaO polyhedra: bicapped square prisms (BaO10), and irregular BaO10 polyhedra. For larger R, Ba5R8Zn4O21 was not stable, and tetragonal BaR2ZnO5(La,Nd) and orthorhombic BaR2ZnO5(SM) phases were observed instead. (C) 2001 International Centre for Diffraction Data. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. BP Amoco Plc, Naperville, IL 60566 USA. RP Wong-Ng, W (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. NR 32 TC 2 Z9 2 U1 1 U2 2 PU J C P D S-INT CENTRE DIFFRACTION DATA PI NEWTOWN SQ PA 12 CAMPUS BLVD, NEWTOWN SQ, PA 19073-3273 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD SEP PY 2001 VL 16 IS 3 BP 131 EP 143 DI 10.1154/1.1367261 PG 13 WC Materials Science, Characterization & Testing SC Materials Science GA 474TF UT WOS:000171122400001 ER PT J AU Mighell, AD AF Mighell, AD TI Ambiguities in powder pattern indexing: A ternary lattice metric singularity SO POWDER DIFFRACTION LA English DT Article DE powder indexing; lattice metric singularity; geometrical ambiguities; nonuniqueness; composite lattices; figure of merit; derivative lattices; d-spacings; indexing programs AB A lattice metric singularity occurs when unit cells defining, two (or more) lattices yield the identical set of unique calculated d-spacings. The existence of such singularities, therefore, has a practical impact on the indexing of powder patterns. Lattice metric singularities often involve lattices that are in a derivative relationship one to another. A variety of types of singularities are possible depending on the number of different lattices involved (i.e., binary, ternary, quaternary), on the nature of the derivative lattice relationship (i.e., subcell/supercell, composite), on the Bravais type of each of the lattices, and on the the volume ratio(s) of primitive cells defining the lattices. In the laboratory, an encounter with a singularity can lead one into a trap; viz., the investigator using an indexing program, or by other means, may determine only one of the lattices with a high figure of merit. When this happens, it is critical to recognize that there exists more than one indexing solution. In a previous work, a binary singularity was described involving a monoclinic and a rhombohedral lattice. In the present work, we describe a second type of singularity-a ternary singularity-in which the two of the three lattices are in a derivative composite relationship. (C) 2001 International Centre for Diffraction Data. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Mighell, AD (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU J C P D S-INT CENTRE DIFFRACTION DATA PI NEWTOWN SQ PA 12 CAMPUS BLVD, NEWTOWN SQ, PA 19073-3273 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD SEP PY 2001 VL 16 IS 3 BP 144 EP 148 DI 10.1154/1.1369789 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA 474TF UT WOS:000171122400002 ER PT J AU Wineland, D Cirac, I Jozsa, R AF Wineland, David Cirac, Ignacio Jozsa, Richard TI Quantum Information Computation SO QUANTUM INFORMATION & COMPUTATION LA English DT Editorial Material C1 [Cirac, Ignacio] Univ Innsbruck, Inst Theoret Phys, A-6020 Innsbruck, Austria. [Jozsa, Richard] Univ Bristol, Dept Comp Sci, Bristol BS8 1TH, Avon, England. [Wineland, David] NIST, Boulder, CO 80309 USA. RP Wineland, D (reprint author), NIST, Boulder, CO 80309 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU RINTON PRESS, INC PI PARAMUS PA 565 EDMUND TERRACE, PARAMUS, NJ 07652 USA SN 1533-7146 J9 QUANTUM INF COMPUT JI Quantum Inform. Comput. PD SEP PY 2001 VL 1 IS 2 BP 1 EP 1 PG 1 WC Computer Science, Theory & Methods; Physics, Particles & Fields; Physics, Mathematical SC Computer Science; Physics GA V31RV UT WOS:000208901600001 ER PT J AU Brown, SW Johnson, BC Yoon, HW Butler, JJ Barnes, RA Biggar, S Spyak, P Thome, K Zalewski, E Helmlinger, M Bruegge, C Schiller, S Fedosejevs, G Gauthier, R Tsuchida, S Machida, S AF Brown, SW Johnson, BC Yoon, HW Butler, JJ Barnes, RA Biggar, S Spyak, P Thome, K Zalewski, E Helmlinger, M Bruegge, C Schiller, S Fedosejevs, G Gauthier, R Tsuchida, S Machida, S TI Radiometric characterization of field radiometers in support of the 1997 Lunar Lake, Nevada, experiment to determine surface reflectance and top-of-atmosphere radiance SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID CALIBRATION AB A continuing series of field campaigns to Lunar Lake, Nevada, has been established to develop measurement protocols and assess the uncertainties of ground-based calibrations of on-orbit satellite sensors. In June 1997, an ensemble of field radiometers was deployed to validate the fundamental reflectance and radiance measurements of the Land Satellite (Landsat-5) Thematic Mapper (TM) and Satellite Pour l'Observation de la Terre (SPOT-2) Haute Resolution Visible (HRV) satellite instruments. Prior their deployment to Lunar Lake, many of the field instruments measured a common sphere source at the University of Arizona (UA). The results, presented in this work, showed variations in the relative stabilities of the field instruments, and demonstrate the need for in-depth characterization of field instruments for an accurate assessment of instrument performance and measurement uncertainty. (C) 2001 Published by Elsevier Science Inc. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Gen Sci Corp, SAIC, Laurel, MD USA. Univ Arizona, Tucson, AZ USA. CALTECH, Jet Prop Lab, NASA, Pasadena, CA USA. S Dakota State Univ, Brookings, SD 57007 USA. Canada Ctr Remote Sensing, Ottawa, ON K1A OY7, Canada. Geol Survey Japan, Tsukuba, Ibaraki 305, Japan. Earth Remote Sensing Data Anal Ctr, Tokyo, Japan. RP Brown, SW (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8442, Gaithersburg, MD 20899 USA. RI Thome, Kurtis/D-7251-2012; Butler, James/D-4188-2013 NR 9 TC 9 Z9 9 U1 1 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD SEP PY 2001 VL 77 IS 3 BP 367 EP 376 DI 10.1016/S0034-4257(01)00215-2 PG 10 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 470BK UT WOS:000170850400010 ER PT J AU Postek, MT Vladar, AE Wells, OC Lowney, JL AF Postek, MT Vladar, AE Wells, OC Lowney, JL TI Application of the low-loss scanning electron microscope image to integrated circuit technology part 1 - Applications to accurate dimension measurements SO SCANNING LA English DT Article DE low-loss electrons; low accelerating voltage; scanning electron microscopy; metrology; backscattered electrons ID ACCELERATING VOLTAGE; SEM AB Scanning electron microscopes (SEMs) are the most extensively used tools for dimensional metrology and defect inspection for integrated circuit technologies with 180 nm and smaller features. Currently, almost all SEMs are designed to collect as many secondary and backscattered electrons as possible. These signals are mainly secondary electrons (SE1, SE2, and SE3) detected with various detection schemes. To facilitate the electron collection, very strong electric and magnetic fields are applied not just in the path of the primary electron beam but to the emerging electrons as well. These new systems provide strong signals, thus better signal-to-noise ratios and thus resulting in higher throughput than older ones. On the other hand, the use of secondary electrons means that measurement results are much more prone to the detrimental effects of electron beam interactions, sample charging, and sample contamination than measurements with higher energy backscattered electrons. The use of backscattered electrons, especially low-loss electrons (LLE), can provide better surface sensitivity, edge accuracy, and repeatability, possibly at the expense of measurement speed. This two-part study investigates the benefits and drawbacks of low-loss electron imaging to edge characterization for dimensional metrology and enhancement of fine surface features done through filtration or separation of the generated LLE signal and the use of energy-dependent signals. Part 1 reviews and illustrates the potential for accurate dimensional measurements at low accelerating voltage by LLE, and Part 2 will concentrate on the enhancement of surface features in chemical-mechanically planarized specimens with the use of a novel LLE detector. C1 NIST, Gaithersburg, MD 20899 USA. IBM Corp, Div Res, Yorktown Hts, NY 10598 USA. RP Postek, MT (reprint author), NIST, 100 Bur Dr,Bldg 200 A 117, Gaithersburg, MD 20899 USA. NR 17 TC 8 Z9 8 U1 0 U2 5 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430-0832 USA SN 0161-0457 J9 SCANNING JI Scanning PD SEP-OCT PY 2001 VL 23 IS 5 BP 298 EP 304 PG 7 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA 474QW UT WOS:000171119200002 PM 11587322 ER PT J AU Wight, SA AF Wight, SA TI Experimental data and model simulations of beam spread in the environmental scanning electron microscope SO SCANNING LA English DT Article DE environmental scanning electron microscope; electron microscope; beam spread; electron scattering; skirt; Monte Carlo; model; simulation ID X-RAY-MICROANALYSIS AB This work describes the comparison of experimental measurements of electron beam spread in the environmental scanning electron microscope with model predictions. Beam spreading is the result of primary electrons being scattered out of the focused beam by interaction with gas molecules in the low-vacuum specimen chamber. The scattered electrons form a skirt of electrons around the central probe. The intensity of the skirt depends on gas pressure in the chamber, beam-gas path length, beam energy, and gas composition. A model has been independently developed that, under a given set of conditions, predicts the radial intensity distribution of the scattered electrons. Experimental measurements of the intensity of the beam skirt were made under controlled conditions for comparison with model predictions of beam skirting. The model predicts the trends observed in the experimentally determined scattering intensities; however, there does appear to be a systematic deviation from the experimental measurements. C1 Natl Inst Stand & Technol, Surface & Microanal Sci Div, Gaithersburg, MD 20899 USA. RP Wight, SA (reprint author), Natl Inst Stand & Technol, Surface & Microanal Sci Div, 100 Bur Dr STOP 8371, Gaithersburg, MD 20899 USA. EM scott.wight@nist.gov NR 15 TC 18 Z9 18 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0161-0457 J9 SCANNING JI Scanning PD SEP-OCT PY 2001 VL 23 IS 5 BP 320 EP 327 PG 8 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA 474QW UT WOS:000171119200005 PM 11587325 ER PT J AU Berman, MS Sherman, K AF Berman, MS Sherman, K TI A towed body sampler for monitoring marine ecosystems SO SEA TECHNOLOGY LA English DT Article C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Narragansett, RI 02882 USA. RP Berman, MS (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Narragansett, RI 02882 USA. NR 5 TC 13 Z9 13 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 USA SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD SEP PY 2001 VL 42 IS 9 BP 48 EP 52 PG 5 WC Engineering, Ocean SC Engineering GA 482EA UT WOS:000171560800007 ER PT J AU Allen, AJ Long, GG Boukari, H Ilavskya, J Kulkarni, A Sampath, S Herman, H Goland, AN AF Allen, AJ Long, GG Boukari, H Ilavskya, J Kulkarni, A Sampath, S Herman, H Goland, AN TI Microstructural characterization studies to relate the properties of thermal-spray coatings to feedstock and spray conditions SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 28th International Conference on Metallurgical Coatings and Thin Films CY APR 30-MAY 05, 2001 CL SAN DIEGO, CALIFORNIA DE ceramics; coatings; neutron scattering; plasma processing and deposition ID ANGLE NEUTRON-SCATTERING; STABILIZED ZIRCONIA; BARRIER COATINGS; DEPOSITS; ALUMINA; CONDUCTIVITY; SURFACE AB This paper reports how microstructural information, obtainable for thick free-standing thermal-spray (plasma-sprayed) ceramic deposits by small-angle scattering, can be used to explore the relationships among the feedstock or spray process conditions, the anisotropic void and crack microstructures of the deposits, and technologically important deposit properties such as thermal conductivity. The application of near-surface small-angle scattering to characterize the microstructure of sub-millimeter-thick coatings on the substrate is also reported for the first time. (C) 2001 Elsevier Science B.V. All rights reserved. C1 NIST, Div Ceram, Gaithersburg, MD 20899 USA. SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Energy Sci & Technol, Upton, NY 11973 USA. RP Allen, AJ (reprint author), NIST, Div Ceram, Gaithersburg, MD 20899 USA. OI Ilavsky, Jan/0000-0003-1982-8900 NR 30 TC 23 Z9 24 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD SEP-OCT PY 2001 VL 146 BP 544 EP 552 DI 10.1016/S0257-8972(01)01433-5 PG 9 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 500DY UT WOS:000172611700084 ER PT J AU Gordon, CJ Kimm-Brinson, KL Padnos, B Ramsdell, JS AF Gordon, CJ Kimm-Brinson, KL Padnos, B Ramsdell, JS TI Acute and delayed thermoregulatory response of mice exposed to brevetoxin SO TOXICON LA English DT Article DE algal toxins; dysthesia; core temperature; behavior; motor activity; telemetry ID SODIUM-CHANNELS; TEMPERATURE; RATS; GYMNODINIUM; HYPOTHERMIA; CIGUATOXIN; SITE AB Thermal dysthesia, characterized by a painful sensation of warm and cool surfaces, is one of many ailments in humans exposed to various marine algal toxins such as brevetoxin (PbTx). There is no animal model to study thermal dysthesia and little is known of the mechanism of action. There is also little known on the acute and delayed thermoregulatory effects of PbTx. In this study, we developed a behavioral system to assess the possible development of thermal dysthesia in mice exposed to PbTx. Female mice were implanted with radiotransmitters to monitor core temperature (T-c) and motor activity (MA). In one experiment, mice were dosed with the control vehicle or 180 mug/kg PbTx and placed on a floor temperature gradient to measure the selected foot temperature (SFT) while air temperature was kept constant. PbTx-treated mice underwent a 10 degreesC reduction in SFT concomitant with a 3 degreesC reduction in T-c within 30 min after exposure. In another study, T-c and MA were monitored in mice maintained in their home cages after dosing with 180 mug/kg PbTx. T-c but not MA increased for 2-5 days after exposure. SFT was unaffected by PbTx when tested 1-12 days after exposure. However, PbTx-treated mice underwent an increase in T-c when placed in the temperature gradient for up to 12 days after exposure. This suggests that PbTx augments the stress-induced hyperthermia from being placed in a novel environment. Overall, acute PbTx exposure leads to a regulated reduction in T-c as characterized by a preference for cooler SFTs and a reduced T-c. Thermal dysthesia was not apparent, but the exaggerated hyperthermic response with a normal SFT in the temperature gradient may suggest an altered processing of thermal stimuli in mice treated with PbTx. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 US EPA, Div Neurotoxicol, Natl Hlth & Environm Effects Res Lab, Res Triangle Pk, NC 27711 USA. Natl Ocean Serv, Marine Biotoxins Program, Ctr Coastal Environm Hlth & Biomol Res, NOAA, Charleston, SC 29412 USA. RP Gordon, CJ (reprint author), US EPA, Div Neurotoxicol, Natl Hlth & Environm Effects Res Lab, Res Triangle Pk, NC 27711 USA. NR 26 TC 14 Z9 15 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0041-0101 J9 TOXICON JI Toxicon PD SEP PY 2001 VL 39 IS 9 BP 1367 EP 1374 DI 10.1016/S0041-0101(01)00092-7 PG 8 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 446ND UT WOS:000169518600013 PM 11384725 ER PT J AU Prager, MH Goodyear, CP AF Prager, MH Goodyear, CP TI Effects of mixed-metric data on production model estimation: Simulation study of a blue-marlin-like stock SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID SURPLUS-PRODUCTION-MODEL; MAKAIRA-NIGRICANS; ATLANTIC; GROWTH; AGE AB An underlying assumption of surplus-production modeling is that the model's two basic data streams (indices of abundance and records of catch) are expressed in the same metric, either biomass or numbers. For lack of data, that assumption is sometimes violated; recent assessments of blue marlin Makaira nigricans, and white marlin Tetrapturus albidus in the Atlantic Ocean, for example, have used indices of abundance based on numbers with indices of catch based on biomass. We examined the effects of using mixed-metric data in production modeling. Our method was a simulation study based on the life history and fishery characteristics of blue marlin in the Atlantic Ocean. Populations were simulated over a range of growth patterns and with either increasing or declining abundance by the use of a simulation model incorporating sex, size, and age structure; sexually dimorphic growth; variation of size at age; a.-e-varying natural mortality; and deterministic or stochastic recruitment. Simulated abundance data were aggregated across ages and combined with random errors to represent the data sets used in assessments. A logistic surplus-production model was then fitted to those simulated data sets. The resulting estimates of maximum sustainable yield and stock status were surprisingly robust to the use of mixed-metric data. Estimates from consistent data were generally more precise but not necessarily less biased. We thus conclude that this use of mixed-metric data is acceptable for blue marlin and similar species. However, errors in estimation varied strongly by the growth pattern assumed, which indicates that better knowledge of growth patterns would allow future assessments to better define likely biases arising from the use of mixed-metric data. C1 NOAA, Populat Dynam Team, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. RP Prager, MH (reprint author), NOAA, Populat Dynam Team, Ctr Coastal Fisheries & Habitat Res, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 26 TC 8 Z9 8 U1 1 U2 1 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 SEP PY 2001 VL 130 IS 5 BP 927 EP 939 DI 10.1577/1548-8659(2001)130<0927:EOMMDO>2.0.CO;2 PG 13 WC Fisheries SC Fisheries GA 467UQ UT WOS:000170722500016 ER PT J AU Rozas, LP Minello, TJ AF Rozas, LP Minello, TJ TI Marsh terracing as a wetland restoration tool for creating fishery habitat SO WETLANDS LA English DT Article DE fishery species; Gulf of Mexico; habitat comparisons; habitat selection; nursery areas; penaeid shrimps; tidal marsh; restoration ID SALT-MARSH; PENAEUS-AZTECUS; GALVESTON BAY; BROWN SHRIMP; NEKTON USE; DECAPOD CRUSTACEANS; NATANT MACROFAUNA; AQUATIC HABITATS; PREDATION RATES; TEXAS USA AB Terracing is a relatively new wetland-restoration technique used to convert shallow subtidal bottom to marsh. This method uses existing bottom sediments to form terraces or ridges at marsh elevation. A terrace field is constructed by arranging these ridges in some pattern that maximizes intertidal edge and minimizes fetch between ridges; the intertidal area is planted with marsh vegetation. We examined the habitat value of terracing for fishery species at Sabine National Wildlife Refuge, Louisiana (USA) in spring and fall 1999 by quantifying and comparing nekton densities in a 9-yr-old terrace field and nearby reference area using a 1-m(2) drop sampler. Decapod crustaceans were more abundant than fishes, composing 62% and 95% of all organisms we collected in spring and fall, respectively. White shrimp Litopenaeus setiferus, daggerblade grass shrimp Palaemonetes pugio, blue crab Callinectes sapidus, and brown shrimp Farfantepenaeus aztecus accounted for 94% of all crustaceans, whereas 60% of all fishes were gulf menhaden Brevoortia patronus. Mean densities of white shrimp (fall), daggerblade grass shrimp, blue crab, and brown shrimp (spring) were significantly greater in terrace marsh than on non-vegetated bottom in the reference pond. Densities of most nekton on non-vegetated bottom were similar in the terrace field and the reference pond, but gulf menhaden and white shrimp had higher densities at terrace pond sites and brown shrimp (spring) were more abundant at reference pond sites. The pattern for biomass was similar to that for density in that the mean biomass of most species was significantly greater at terrace marsh sites than reference pond sites and similar at terrace and reference pond sites. Terrace marsh, however, was not functionally equivalent to natural marsh, as mean densities of daggerblade grass shrimp (fall), brown shrimp (spring), and blue crab and mean biomass of white shrimp (fall), striped mullet Mugil cephalus (spring), and spotted seatrout Cynoscion nebulosus (fall) were greater at reference marsh sites than terrace marsh sites. Using these density and biomass patterns and the percentage of marsh and pond area in the terrace field, we concluded that terrace fields support higher standing crops of most fishery species compared with shallow marsh ponds of similar size. Future restoration projects could include design changes to increase the proportion of marsh in a terrace field and enhance the habitat value of marsh terraces for fishery species. C1 SE Fisheries Sci Ctr, NOAA, Natl Marine Fisheries Serv, Galveston, TX 77551 USA. RP Rozas, LP (reprint author), SE Fisheries Sci Ctr, NOAA, Natl Marine Fisheries Serv, 4700 Ave U, Galveston, TX 77551 USA. NR 45 TC 28 Z9 29 U1 4 U2 25 PU SOC WETLAND SCIENTISTS PI LAWRENCE PA 810 E TENTH ST, P O BOX 1897, LAWRENCE, KS 66044 USA SN 0277-5212 J9 WETLANDS JI Wetlands PD SEP PY 2001 VL 21 IS 3 BP 327 EP 341 DI 10.1672/0277-5212(2001)021[0327:MTAAWR]2.0.CO;2 PG 15 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 477KB UT WOS:000171281800002 ER PT J AU Gloor, M Bakwin, P Hurst, D Lock, L Draxler, R Tans, P AF Gloor, M Bakwin, P Hurst, D Lock, L Draxler, R Tans, P TI What is the concentration footprint of a tall tower? SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-DIOXIDE; FLUX MEASUREMENTS; SURFACE-LAYER; UNITED-STATES; TETRACHLOROETHENE; EMISSIONS; DICHLOROMETHANE; TRICHLOROETHENE; ATMOSPHERE; SYSTEM AB Studies that have attempted to estimate sources and sinks of trace gases such as CO2 with inverse calculations unanimously identify the lack of continental stations as a prime obstacle. Continental stations have traditionally been avoided because of the difficulty of interpretation due to large time-variability of trace substance mixing ratios. Large variability is caused by the proximity to the strongly variable sources in space and time and the complicated airflow within the lowermost 100-200 m of the planetary boundary layer. To address the need for continental stations and to overcome the problems associated with them, the National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostics Laboratory started in 1992 to measure CO2 and other trace gases on tall television transmission towers [Bakwin et al, 1995]. An essential question in connection with these tower measurements is the area around the tower from which fluxes substantially contribute to the observed short-term variability of trace gas mixing ratios. We present here a simple data and back trajectory-based method to estimate the fraction of the observed short-term variability explained by a localized flux around a tall television transmission tower in Wisconsin in dependence of its location relative to the tower (the concentration "footprint"). We find that the timescale over which the imprint of surface fluxes on air parcels before its arrival at the tower axe still discernible in the mixing ratio variations observed at the tower is of the order of 1.5 days. Based on this timescale and the characteristics of air parcel trajectories, we infer a spatial extent of the footprint of the order of 10(6) km(2), or roughly a tenth of the area of the United States. This is encouraging evidence that tall tower measurements may be useful in global inversions and may also have implications for monitoring fluxes of anthropogenic trace substances on regional scales. C1 Princeton Univ, Atmospher & Ocean Sci Dept, Princeton, NJ 08544 USA. NOAA, Dept Commerce, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP Gloor, M (reprint author), Max Planck Inst Biogeochem, Postfach 100164, D-07701 Jena, Germany. EM mgloor@bgc-jena.mpg.de; pbakwin@cmdl.noaa.gov; dhurst@cmdl.noaa.gov; rdraxler@arlrisc.arlhq.noaa.gov; ptans@cmdl.noaa.gov RI Hurst, Dale/D-1554-2016 OI Hurst, Dale/0000-0002-6315-2322 NR 27 TC 73 Z9 74 U1 0 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 AUG 27 PY 2001 VL 106 IS D16 BP 17831 EP 17840 DI 10.1029/2001JD900021 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465FR UT WOS:000170579400009 ER PT J AU Lohmann, D AF Lohmann, D TI Comment on "modeling ground heat flux in land surface parameterization schemes" by Xu Liang, Eric F. Wood, and Dennis P. Lettenmaier SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material ID TEMPERATURE C1 NOAA, NWS, NCEP, EMC, Suitland, MD 20746 USA. RP Lohmann, D (reprint author), NOAA, NWS, NCEP, EMC, 5200 Auth Rd, Suitland, MD 20746 USA. EM dlohmann@ncep.noaa.gov OI Wood, Eric/0000-0001-7037-9675 NR 8 TC 1 Z9 1 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 2001 VL 106 IS D16 BP 17889 EP 17892 DI 10.1029/2001JD900105 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465FR UT WOS:000170579400013 ER PT J AU Gilliland, A Abbitt, PJ AF Gilliland, A Abbitt, PJ TI A sensitivity study of the discrete Kalman filter (DKF) to initial condition discrepancies SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID VARIATIONAL DATA ASSIMILATION; ATMOSPHERIC CO2 SOURCES; TRANSPORT MODEL; INVERSE METHOD; MIXING RATIOS; TRACE GASES; PART II; EMISSIONS; SINKS; ADJOINT AB In several previous studies the discrete Kalman filter (DKF) has been used in an adaptive-iterative mode to deduce time-varying air quality emissions. While it is not expressly stated in previous literature on this method, the DKF assumes that the initial modeled and observed concentrations are equal. Careful consideration of this assumption is critical for urban or regional scale air quality models because agreement of initial concentrations with observations is not always a requirement or priority when using these models. The purpose of this paper is to clarify the initial condition assumption in the DKF and to investigate potential implications when the assumption is violated. We focus on the adaptive-iterative implementation of the DKF since we arc specifically interested in deducing time-varying air quality emissions. A complete description of the adaptive-iterative DKF as implemented by other authors is provided. A case study in the form of a pseudodata test or identical twin experiment is presented to show that if the initial condition assumption is violated, the adaptive-iterative DKF can produce biased emissions to compensate for the initial modeled and observed concentration differences. The magnitude and longevity of the resulting compensating error depends on the influence of the initial concentrations, as the error is removed more quickly for highly reactive species than for less reactive species (e.g., isoprene versus CO). C1 N Carolina State Univ, Dept Stat, Raleigh, NC 27695 USA. NOAA, Atmospher Sci Modeling Div, Air Resources Lab, Res Triangle Pk, NC USA. RP Gilliland, A (reprint author), US EPA, Natl Exposure Res Lab, MD-80, Res Triangle Pk, NC 27711 USA. NR 45 TC 14 Z9 15 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 2001 VL 106 IS D16 BP 17939 EP 17952 DI 10.1029/2001JD900174 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465FR UT WOS:000170579400019 ER PT J AU Sokolik, IN Winker, DM Bergametti, G Gillette, DA Carmichael, G Kaufman, YJ Gomes, L Schuetz, L Penner, JE AF Sokolik, IN Winker, DM Bergametti, G Gillette, DA Carmichael, G Kaufman, YJ Gomes, L Schuetz, L Penner, JE TI Introduction to special section: Outstanding problems in quantifying the radiative impacts of mineral dust SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AEROSOL OPTICAL-PROPERTIES; TROPOSPHERIC AEROSOL; LIGHT-ABSORPTION; LAND SURFACES; SAHARAN DUST; WATER-VAPOR; SATELLITE; POLARIZATION; RETRIEVAL; SPACE AB This paper provides an introduction to the special section of the Journal of Geophysical Research on mineral dust. We briefly review the current experimental and theoretical approaches used to quantify the dust radiative impacts, highlight the outstanding issues, and discuss possible strategies to overcome the emerging problems. We also introduce the contributing papers of this special section. Despite the recent notable advances in dust studies, we demonstrate that the radiative effects of dust remain poorly quantified due to both limited data and incomplete understanding of relative physical and chemical processes. The foremost needs are (1) to quantify the spatial and temporal variations of dust burden in the atmosphere and develop a predictive capability for the size- and composition-resolved dust particle distribution; (2) to develop a quantitative description of the processes that control the spatial and temporal variabilities of dust physical and chemical properties and radiative effects; (3) to develop new instrumentation (especially to measure the dust particle size distribution in a wide range from about 0.01 mum to 100 tm, scattering phase function and light absorption by dust particles); and (4) to develop new techniques for interpreting and merging the diverse information from satellite remote sensing, in situ and ground-based measurements, laboratory studies, and model simulations. Because dust distribution and effects are heterogeneous, both spatially and temporally, a promising strategy to advance our knowledge is to perform comprehensive studies at the targeted regions affected by mineral dust of both natural and anthropogenic origin. C1 Univ Colorado, Boulder, CO 80309 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Paris 12, Paris, France. NOAA, ARL, Res Triangle Pk, NC 27615 USA. Univ Iowa, Iowa City, IA 52240 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johannes Gutenberg Univ Mainz, D-55099 Mainz, Germany. Univ Michigan, Ann Arbor, MI 48109 USA. RP Sokolik, IN (reprint author), Univ Colorado, Boulder, CO 80309 USA. EM sokolik@lasp.colorado.edu; d.m.winker@larc.nasa.gov; ebergametti@lisa.univ-paris12.fr; GILLETTE.DALE@epamail.epa.gov; gcarmich@engineering.uiowa.edu; kaufman@climate.gsfe.nasa.gov; gomes@lisa.univ-paris12.fr; schuetz@mail.uni-mainz.de; penner@umich.edu RI Penner, Joyce/J-1719-2012 NR 59 TC 292 Z9 312 U1 0 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 2001 VL 106 IS D16 BP 18015 EP 18027 DI 10.1029/2000JD900498 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465FR UT WOS:000170579400025 ER PT J AU Gao, Y Anderson, JR AF Gao, Y Anderson, JR TI Characteristics of Chinese aerosols determined by individual-particle analysis SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NORTH PACIFIC-OCEAN; ANTHROPOGENIC AEROSOLS; MINERAL AEROSOLS; DUST; TROPOSPHERE; ULTRAVIOLET; DEPOSITION; TRANSPORT; SULFATE; NITRATE AB Tropospheric aerosols that originate in China and are transported over the North Pacific Ocean have potentially significant impacts on regional and global climate. These aerosols are complex mixtures of soil dust and anthropogenic particles from a variety of sources, including fossil fuel combustion, biomass burning, mining, smelting, and other industrial processes, plus reaction products of heterogeneous processes that affect these particles during transport. In the coastal marine atmosphere, these particles could be further mixed with marine aerosols. To provide examples of the diversity of chemical and physical properties of east Asian aerosols in the spring, individual aerosol particle samples were collected in April and May 1999 in three different environments in China: Qingdao on the coast of the East China Sea, Beijing in the northeast interior, and Mount Waliguan in remote northwestern China. Results reveal that aerosols in this region are complex and heterogeneous. In addition to significant differences in aerosol composition and size distributions among the samples, each sample contains a large number of polyphase aggregates. Many of the particles also have irregular shapes; for a number of the particle types, the irregular shapes should persist even at high ambient RH. Because composition, degree and nature of polyphase aggregation, and shape all effect aerosol radiative properties, the complex state of cast Asian aerosols presents a challenge for the modeling of aerosol radiative forcing in the region. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. Arizona State Univ, Program Environm Fluid Dynam, Tempe, AZ USA. Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08903 USA. RP Gao, Y (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. EM yuangao@splash.princeton.edu; janderson@asu.edu NR 40 TC 80 Z9 86 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 2001 VL 106 IS D16 BP 18037 EP 18045 DI 10.1029/2000JD900725 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465FR UT WOS:000170579400027 ER PT J AU Gillette, DA Niemeyer, TC Helm, PJ AF Gillette, DA Niemeyer, TC Helm, PJ TI Supply-limited horizontal sand drift at an ephemerally crusted, unvegetated saline playa SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID THRESHOLD FRICTION VELOCITY; WIND EROSION; OWENS-LAKE; MASS FLUX; DUST; SALTATION; CALIFORNIA; PARTICLES AB A site at Owens Dry Lake was observed for more than 4 years. The site was a vegetation-free saline playa where the surface formed "ephemeral crusts," crusts that form after rainfall. Sometimes these crusts were destroyed and often a layer of particles on the crust would engage in vigorous aeolian activity. Three "phases" of active sand drifting are defined as almost no movement (extreme supply limitation), loose particles on crust with some degree of sand drift (moderate supply limitation), and unlimited source movement corresponding to a destroyed surface crust (unlimited supply). These "phases" occurred 45, 49, and 6% of the time, respectively. The accumulation of loose particles on the crust was mostly the result of in situ formation. Crusted sediments with loose particles on top can exhibit mass flux rates about the same as for noncrusted sediments. Crusted sediments limit or eliminate sand drift in two conditions: for rough crusts that effect a sufficiently high threshold friction velocity (above the wind friction velocity) and for limited amounts of loose particles on the crust where particle supply is less than would be transported in normal saltation for a thick sandy surface. These "supply-limited" cases are similar to wind erosion of limited spilled material on a hard concrete surface. We quantified "Supply limitation" by defining a "potential" or "supply unlimited" sand drift function Q = AG where A represents supply limitation that decreases as the particle source is depleted. Here Q is the mass of sand transported through a surface perpendicular to the ground and to the wind and having unit width during time period t, and G = integral u(*)(u(*)(2) - u(*t)(2)) dt for u(*) > u(*t). G is integrated for the same time period t as for Q, u(*) is the friction velocity of the wind, and u(*t) is the threshold friction velocity of the wind. Hard crusts (usually formed in the summer) tended to show almost no change of threshold friction velocity with time and often gave total protection from wind erosion. Rough crusts provided sufficient protection expressed as high threshold friction velocities. For these high threshold friction velocities, aeolian activity was greatly reduced or practically prevented. The softest crusts, usually formed in the winter, provided much less protection and sometimes were destroyed by the wind. Following this destruction the "potential" or "supply unlimited" sand drift would be observed. C1 NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27711 USA. Niemeyer, Ridgecrest, CA 93555 USA. US Geol Survey, Flagstaff, AZ 86001 USA. RP Gillette, DA (reprint author), NOAA, Air Resources Lab, Atmospher Sci Modeling Div, MD 81, Res Triangle Pk, NC 27711 USA. NR 23 TC 31 Z9 32 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 2001 VL 106 IS D16 BP 18085 EP 18098 DI 10.1029/2000JD900324 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465FR UT WOS:000170579400032 ER PT J AU Chylek, P Lesins, G Lohmann, U AF Chylek, P Lesins, G Lohmann, U TI Enhancement of dust source area during past glacial periods due to changes of the Hadley circulation SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID EARTHS ROTATION RATE; GENERAL-CIRCULATION; DESERT DUST; ICE CORE; CLIMATE; MODEL; ATMOSPHERE; AEROSOLS; ANTARCTICA; MAXIMUM AB Tropical deserts (e.g., Sahara, Arabian desert, Australian desert) are located within the Hadley circulation. Most of the dust uplifted from these deserts is carried by trade winds and deposited in tropical oceans with very little, if any, transported to polar regions. During glacial periods the dust concentrations in polar ice cores were a factor of 10 to 100 higher than during interglacial periods, including the current Holocene. The early general circulation model simulations of the past glacial climate were not able to reproduce these high mineral dust concentrations; the most recent attempts achieve an increased dust transport to polar regions by extending dust source areas to higher latitudes. We present a hypothesis that during glacial periods the Hadley cell is confined closer to the equator. This contraction of the Hadley circulation leads to the geographical change of the boundary between the tropical and the midlatitude circulation regimes. During the glacial periods a considerable fraction of the current tropical deserts was located outside the region of the Hadley circulation. This allowed the dust to be uplifted and transported by midlatitude storm systems to the polar regions. We present a model for the contraction of the Hadley circulation during the past glacial periods based on the Schneider-Lindzen and Held-Hou model of symmetric tropical circulation and on the assumption that the tropical sea surface temperatures were lower during glacial periods than they are today. C1 Dalhousie Univ, Dept Phys, Atmospher Sci Program, Halifax, NS B3H 3J5, Canada. Dalhousie Univ, Dept Oceanog, Atmospher Sci Program, Halifax, NS B3H 3J5, Canada. NOAA, Air Resources Lab, Boulder, CO 80303 USA. RP Chylek, P (reprint author), Dalhousie Univ, Dept Phys, Atmospher Sci Program, Halifax, NS B3H 3J5, Canada. RI Lohmann, Ulrike/B-6153-2009 OI Lohmann, Ulrike/0000-0001-8885-3785 NR 45 TC 20 Z9 21 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 2001 VL 106 IS D16 BP 18477 EP 18485 DI 10.1029/2000JD900583 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465FR UT WOS:000170579400058 ER PT J AU Burkhart, BE Gopalkrishnan, PV Hudson, SD Jamieson, AM Rother, MA Davis, RH AF Burkhart, BE Gopalkrishnan, PV Hudson, SD Jamieson, AM Rother, MA Davis, RH TI Droplet growth by coalescence in binary fluid mixtures SO PHYSICAL REVIEW LETTERS LA English DT Article ID SHEAR-FLOW; DEFORMABLE DROPS; POLYMER BLENDS; COLLISION; EMULSIONS AB The evolution of the drop-size distribution in immiscible fluid mixtures following well-specified shear histories is investigated by in situ microscopy, allowing determination of the shear-induced coalescence efficiency epsilon. At small capillary number Ca, epsilon is constant, whereas at larger values of Ca, epsilon decreases, in agreement with theory accounting for slight deformation of the drops in close approach. Coalescence causes the drop-size distribution to broaden in general, but greater deformation of the larger drops at high shear rates causes the drop-size distribution to remain narrow. C1 Case Western Reserve Univ, Dept Macromol Sci, Cleveland, OH 44106 USA. Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Univ Colorado, Dept Chem Engn, Boulder, CO 80309 USA. RP Burkhart, BE (reprint author), Case Western Reserve Univ, Dept Macromol Sci, Cleveland, OH 44106 USA. NR 21 TC 26 Z9 26 U1 1 U2 17 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 AUG 27 PY 2001 VL 87 IS 9 BP art. no. EP 098304 DI 10.1103/PhysRevLett.87.098304 PG 4 WC Physics, Multidisciplinary SC Physics GA 467JE UT WOS:000170698000048 PM 11531604 ER PT J AU Desoutter, M Munroe, TA Chapleau, F AF Desoutter, M Munroe, TA Chapleau, F TI Nomenclatural status of Brachirus Swainson, Synaptura Cantor and Euryglossa Kaup (Soleidae, Pleuronectiformes) SO ICHTHYOLOGICAL RESEARCH LA English DT Article DE Nomenclature; Soleidae; Brachirus; Synaptura; Euryglossa ID REASSESSMENT AB We find that Brachirus Swainson, 1839 is a valid soleid (Pleuronectiformes) genus name, Euryglossa Kaup, 1858 is an invalid soleid genus name, and Synaptura Cantor, 1849 is a junior objective synonym of Brachirus. However, for the sake of taxonomic stability and because Synaptura Cantor, 1849 has had a long-term consistent usage within the Soleidae for four species (S. commersoni, S. lusitanica, S. marginata, and S. albomaculata) forming a monophyletic group, we will petition the International Commission on Zoological Nomenclature to recognize Synaptura Cantor, 1849 as a valid genus name with its type-species being Pleuronectes commersoni Lacepede, 1802. C1 Museum Natl Hist Nat, Ichtyol Gen & Appl Lab, F-75231 Paris 05, France. Natl Museum Nat Hist, Natl Marine Fisheries Serv Systemat Lab, Washington, DC 20560 USA. Univ Ottawa, Ottawa Carleton Inst Biol, Dept Biol, Ottawa, ON K1N 6N5, Canada. RP Chapleau, F (reprint author), Museum Natl Hist Nat, Ichtyol Gen & Appl Lab, 43 Rue Cuvier, F-75231 Paris 05, France. NR 26 TC 1 Z9 1 U1 2 U2 2 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 AUG 25 PY 2001 VL 48 IS 3 BP 325 EP 327 DI 10.1007/s10228-001-8154-1 PG 3 WC Zoology SC Zoology GA 471JU UT WOS:000170926900016 ER PT J AU Vakhtin, AB Heard, DE Smith, IWM Leone, SR AF Vakhtin, AB Heard, DE Smith, IWM Leone, SR TI Kinetics of reactions of C2H radical with acetylene, O-2, methylacetylene, and allene in a pulsed Laval nozzle apparatus at T=103 K SO CHEMICAL PHYSICS LETTERS LA English DT Article ID RATE COEFFICIENTS; TEMPERATURE-DEPENDENCE; TITANS ATMOSPHERE; RATE CONSTANTS; SPECTROSCOPY; CH AB The rate constants of the reactions of C2H radical with HC=CH (k(1)), O-2 (k(2)), CH3C=CH (k(3)), and H2C=C=CH2 (k(4)) are measured at 103 K using a pulsed Laval nozzle supersonic expansion and the CH(A(2)Delta) chemiluminescence monitor method: k(1) = (1.3 +/- 0.3) x 10(-10), k(2) = (3.8 +/- 0.9) x 10(-11), k(3) = (2.7 +/- 0.6) x 10(-11), and k(4) = (2.5 +/- 0.6) x 10(-10) cm(3) molecule(-1) s(-1). These values are compared to previous results and measurements in a continuous Laval nozzle apparatus (accompanying paper by Carty et al.). The non-Arrhenius behavior and possible implications of the results for atmospheric chemistry of Titan are discussed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Leone, SR (reprint author), Univ Colorado, Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. OI Heard, Dwayne/0000-0002-0357-6238 NR 33 TC 50 Z9 50 U1 1 U2 14 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 AUG 24 PY 2001 VL 344 IS 3-4 BP 317 EP 324 DI 10.1016/S0009-2614(01)00681-9 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 466ZL UT WOS:000170676000012 ER PT J AU Vakhtin, AB Lee, S Heard, DE Smith, IWM Leone, SR AF Vakhtin, AB Lee, S Heard, DE Smith, IWM Leone, SR TI Low-temperature kinetics of reactions of the OH radical with propene and 1-butene studied by a pulsed Laval nozzle apparatus combined with laser-induced fluorescence SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID NEUTRAL-NEUTRAL REACTIONS; ROTATIONAL ENERGY-TRANSFER; VERY-LOW TEMPERATURES; GAS-PHASE REACTIONS; RATE COEFFICIENTS; INTERSTELLAR CLOUDS; SATURNS ATMOSPHERE; RATE CONSTANTS; 359 K; C2H AB The kinetics of the reactions of the OH radical with propene and 1-butene are studied at T = 103 K. The low-temperature environment is provided by a pulsed Laval nozzle supersonic expansion of nitrogen with admixed radical precursor and reactant gases. The gas number density and temperature distributions in the flow are characterized by both dynamic pressure measurements and laser-induced fluorescence (LIF) spectroscopy of OH radicals excited in the (1,0) band of the A(2)Sigma (+) - X(2)Pi (i), transition. For the kinetic measurements, the OH radical decay profiles in the presence of reactants are monitored by LIF. The rate constants of the reactions of OH with propylene and 1-butene are measured at T = 103 K to be (0.81 +/- 0.18) x 10(-10) and (1.24 +/- 0.27) x 10(-10) cm(3) molecule(-1) s(-1), respectively. The observed negative temperature dependences of the rate constants for both reactions studied by the pulsed Laval nozzle system show good agreement with both low-temperature and high-temperature kinetic data available in the literature. C1 Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Leone, SR (reprint author), Natl Inst Stand & Technol, JILA, 325 Broadway, Boulder, CO 80309 USA. OI Heard, Dwayne/0000-0002-0357-6238 NR 45 TC 34 Z9 34 U1 1 U2 15 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 AUG 23 PY 2001 VL 105 IS 33 BP 7889 EP 7895 DI 10.1021/jp010809d PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 463ZG UT WOS:000170506700015 ER PT J AU Coakley, KJ AF Coakley, KJ TI Neutron lifetime experiments using magnetically trapped neutrons: optimal background correction strategies SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE background correction; design of experiments; magnetic trap; neutron lifetime; parametric inference; ultra cold neutrons AB In the first stage of each run of a neutron lifetime experiment, a magnetic trap is filled with neutrons. In the second stage of each run, decay events plus background events are observed. In a separate experiment, background is measured. The mean lifetime is estimated by fitting a two parameter exponential model to the background-corrected data. For two models of the background signal, I determine the optimal ratio of the number of "background-only" measurements to, the number of primary "neutron decay plus background" measurements. Further, for each run, I determine the optimal allocation of time for filling and for observing decay events. For the case where the background consists of an activated material (aluminum) plus a stationary Poisson process, the asymptotic standard error of the lifetime estimate computed from the background-corrected data is lower than the asymptotic standard error computed from the uncorrected data. For the case where the background is a stationary Poisson process, background correction is desirable provided that the background intensity is sufficiently small compared to the rate at which neutrons enter the trap. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Inst Stand & Technol, Stat Engn Div, Boulder, CO 80305 USA. RP Coakley, KJ (reprint author), Natl Inst Stand & Technol, Stat Engn Div, 325 Broadway,Mail Stop 898-02, Boulder, CO 80305 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 2001 VL 469 IS 3 BP 354 EP 363 DI 10.1016/S0168-9002(01)00788-4 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 470DJ UT WOS:000170854900008 ER PT J AU Davis, S Farnik, M Uy, D Nesbitt, DJ AF Davis, S Farnik, M Uy, D Nesbitt, DJ TI Concentration modulation spectroscopy with a pulsed slit supersonic discharge expansion source SO CHEMICAL PHYSICS LETTERS LA English DT Article ID HIGH-RESOLUTION SPECTROSCOPY; MOLECULAR-IONS; ABSORPTION-SPECTROSCOPY; TRANSIENT MOLECULES; LASER SPECTROSCOPY; FREE-RADICALS; INFRARED-LASER; NU-1 AB Frequency modulated discharges are combined with pulsed slit supersonic expansions to provide an intense, long path source of jet-cooled radicals/molecular ions for direct absorption laser spectroscopy. The high modulation frequency (100 kHz) permits lock-in detection of the modulated absorbance signals at sensitivities down to 7.3 x 10(-7) absorbance/Hz(1/2) (within 40% of the shot noise limit) and provides excellent discrimination for radical or molecular ion spectra in the presence of much higher precusor concentrations. The sensitivity of these methods is demonstrated with direct absorption spectral data on sample jet-cooled molecular ions (H-3(+)) and hydrocarbon radicals (CH3CH2). (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, Joint Inst Lab Astrophys, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Nesbitt, DJ (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Dept Chem & Biochem, Boulder, CO 80309 USA. RI Farnik, Michal/F-5274-2014 OI Farnik, Michal/0000-0002-7106-0719 NR 28 TC 38 Z9 38 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD AUG 17 PY 2001 VL 344 IS 1-2 BP 23 EP 30 DI 10.1016/S0009-2614(01)00746-1 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 465ZE UT WOS:000170619200005 ER PT J AU Magnuson, JJ Safina, C Sissenwine, MP AF Magnuson, JJ Safina, C Sissenwine, MP TI Ecology and conservation - Whose fish are they anyway? SO SCIENCE LA English DT Editorial Material ID ATLANTIC C1 Univ Wisconsin, Ctr Limnol, Madison, WI 53706 USA. Natl Audubon Soc, Living Oceans Program, Islip, NY 11751 USA. NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Magnuson, JJ (reprint author), Univ Wisconsin, Ctr Limnol, Madison, WI 53706 USA. NR 8 TC 16 Z9 16 U1 1 U2 6 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 AUG 17 PY 2001 VL 293 IS 5533 BP 1267 EP 1268 DI 10.1126/science.1064052 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 463TD UT WOS:000170492600024 PM 11509715 ER PT J AU Shelton, RK Ma, LS Kapteyn, HC Murnane, MM Hall, JL Ye, J AF Shelton, RK Ma, LS Kapteyn, HC Murnane, MM Hall, JL Ye, J TI Phase-coherent optical pulse synthesis from separate femtosecond lasers SO SCIENCE LA English DT Article ID TI-SAPPHIRE LASER; MODE-LOCKED LASER; SUBFEMTOSECOND PULSES; FREQUENCY-MEASUREMENT; GENERATION; SCATTERING; EVOLUTION AB We generated a coherently synthesized optical pulse from two independent mode-locked femtosecond lasers, providing a route to extend the coherent bandwidth available for ultrafast science. The two separate lasers (one centered at 760 nanometers wavelength, the other at 810 nanometers) are tightly synchronized and phase-locked. Coherence between the two lasers is demonstrated via spectral interferometry and second-order field cross-correlation. Measurements reveal a coherently synthesized pulse that has a temporally narrower second-order autocorrelation width and that exhibits a larger amplitude than the individual laser outputs. This work represents a new and flexible approach to the synthesis of coherent tight. C1 Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. E China Normal Univ, Dept Phys, Shanghai 200062, Peoples R China. RP Ye, J (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80309 USA. RI Ye, Jun/C-3312-2011; Kapteyn, Henry/H-6559-2011 OI Kapteyn, Henry/0000-0001-8386-6317 NR 27 TC 197 Z9 204 U1 14 U2 30 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 AUG 17 PY 2001 VL 293 IS 5533 BP 1286 EP 1289 DI 10.1126/science.1061754 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 463TD UT WOS:000170492600030 PM 11509721 ER PT J AU Block, BA Dewar, H Blackwell, SB Williams, TD Prince, ED Farwell, CJ Boustany, A Teo, SLH Seitz, A Walli, A Fudge, D AF Block, BA Dewar, H Blackwell, SB Williams, TD Prince, ED Farwell, CJ Boustany, A Teo, SLH Seitz, A Walli, A Fudge, D TI Migratory movements, depth preferences, and thermal biology of Atlantic bluefin tuna SO SCIENCE LA English DT Article ID GULF-OF-MEXICO; THUNNUS-THYNNUS; SATELLITE; FISH; TRACKING; EAST; TAGS AB The deployment of electronic data storage tags that are surgically implanted or satellite-linked provides marine researchers with new ways to examine the movements, environmental preferences, and physiology of pelagic vertebrates. We report the results obtained from tagging of Atlantic bluefin tuna with implantable archival and pop-up satellite archival tags. The electronic tagging data provide insights into the seasonal movements and environmental preferences of this species. Bluefin tuna dive to depths of >1000 meters and maintain a warm body temperature. Western-tagged bluefin tuna make trans-Atlantic migrations and they frequent spawning grounds in the Gulf of Mexico and eastern Mediterranean. These data are critical for the future management and conservation of bluefin tuna in the Atlantic. C1 Stanford Univ, Hopkins Marine Stn, Tuna Res & Conservat Ctr, Pacific Grove, CA 93950 USA. Pfleger Inst Environm Res, Oceanside, CA 92054 USA. Monterey Bay Aquarium, Monterey, CA 93940 USA. Natl Marine Fisheries Serv, Miami, FL 33149 USA. RP Block, BA (reprint author), Stanford Univ, Hopkins Marine Stn, Tuna Res & Conservat Ctr, Pacific Grove, CA 93950 USA. NR 27 TC 384 Z9 400 U1 15 U2 151 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 AUG 17 PY 2001 VL 293 IS 5533 BP 1310 EP 1314 DI 10.1126/science.1061197 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 463TD UT WOS:000170492600038 PM 11509729 ER PT J AU Maxelon, M Pundt, A Pyckhout-Hintzen, W Barker, J Kirchheim, R AF Maxelon, M Pundt, A Pyckhout-Hintzen, W Barker, J Kirchheim, R TI Interaction of hydrogen and deuterium with dislocations in palladium as observed by small angle neutron scattering SO ACTA MATERIALIA LA English DT Article DE neutron scattering; dislocations; Portevin-Le Chatalier effects; segregation; hydrogen in metals ID METALS; DEFECTS; HREM AB Small angle neutron scattering (SANS) measurements on Pd samples containing dislocations with a density of a few 10(11) cm(-2) reveal an additional intensity for a scattering vector of 0.02 Angstrom (1) to 0.2 Angstrom (1) after loading with hydrogen (H) or deuterium (D). The corresponding net cross section is inversely proportional to the scattering vector as expected for line type scattering objects with a superimposed exponential decrease stemming from scattering within the Guinier-regime. This experimental finding is in accordance with a model where extended segregation of H or D within the dilated regions of edge dislocations occurs. In a first order approximation this corresponds to a precipitation of cylindrically shaped hydrides along the dislocation line and can be treated quantitatively yielding radii in agreement with SANS data. Whereas gas volumetric measurements at the same total concentration reveal no difference for the amount of H- and D-segregation, there is a pronounced effective difference in SANS intensities which cannot be explained by the different scattering lengths alone. However, the different sign of the latter quantity in combinations with an expected volume expansion within the hydride/deuteride region provides a reasonable explanation of the intensity difference observed. Knowing the amount of segregated H or D from gas volumetry and the dislocation density from electron microscopy the SANS results can be explained in a self consistent way. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Gottingen, Inst Mat Phys, D-37073 Gottingen, Germany. FZ Julich, Inst Festkorperforsch, Julich, Germany. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Kirchheim, R (reprint author), Univ Gottingen, Inst Mat Phys, Hosp Str 3-7, D-37073 Gottingen, Germany. NR 28 TC 40 Z9 40 U1 1 U2 15 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 AUG 16 PY 2001 VL 49 IS 14 BP 2625 EP 2634 DI 10.1016/S1359-6454(01)00185-9 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 462TF UT WOS:000170435300002 ER PT J AU Duckham, A Knutsen, RD Engler, O AF Duckham, A Knutsen, RD Engler, O TI Influence of deformation variables on the formation of copper-type shear bands in Al-lMg SO ACTA MATERIALIA LA English DT Article DE shear bands; texture; aluminium; hot deformation ID PLANE-STRAIN COMPRESSION; ROLLING TEXTURE DEVELOPMENT; SINGLE-CRYSTALS; FCC METALS; RECRYSTALLIZATION; ALLOYS; MICROSTRUCTURE; ORIENTATION; ALUMINUM; FLOW AB The formation of copper-type or grain-scale shear bands in Al-lMg during plane strain compression (PSC) is described as a function of strain, strain rate and deformation temperature. Shear banding is observed to decrease dramatically in strength over a small range of the Zener-Hollomon parameter (Z) at Z approximately equal to 1.0x10(11) s(-1). This sharp transition in shear band formation is seen to correlate exactly with a sharp increase in dynamic recovery during deformation, as inferred from flow stress measurements, hardness measurements and microstructural analysis of as-deformed specimens. The observed correlation of shear band formation and dynamic recovery during deformation provides further insight into the basic mechanisms of shear band formation. The influence of shear bands on deformation texture is also investigated and is seen to affect the relative intensities of, and precise position along, the beta -fibre. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Cape Town, Ctr Mat Engn, ZA-7701 Rondebosch, South Africa. Los Alamos Natl Lab, Mat Sci & Technol Div MST 8, Los Alamos, NM 87545 USA. RP Duckham, A (reprint author), Natl Inst Stand & Technol, MSEL, Gaithersburg, MD 20899 USA. NR 44 TC 50 Z9 50 U1 3 U2 16 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 AUG 16 PY 2001 VL 49 IS 14 BP 2739 EP 2749 DI 10.1016/S1359-6454(01)00166-5 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 462TF UT WOS:000170435300013 ER PT J AU Menyhard, M Zsolt, G Chen, PJ Powell, CJ McMichael, RD Egelhoff, WF AF Menyhard, M Zsolt, G Chen, PJ Powell, CJ McMichael, RD Egelhoff, WF TI Structural effects in the growth of giant magnetoresistance (GMR) spin valves SO APPLIED SURFACE SCIENCE LA English DT Article DE giant magnetoresistance; auger depth-profiling; growth; metal-metal magnetic thin-film structure; interface morphology ID AUGER-ELECTRON SPECTROSCOPY; DEPTH-RESOLUTION; ENHANCED MAGNETORESISTANCE; MULTILAYERS AB An investigation has been made of the thin-film structure and interface morphology of giant magnetoresistance (GMR) spin valves of the cobalt/copper/cobalt (Co/Cu/Co) type that were grown on polycrystalline NiO substrates at three different temperatures (150, 300 and 450 K). Sputter-depth-profile analyses indicate that the quality of the layering in the Co/Cu/Co structure was only slightly better for the 150 K sample than for the 300 K sample. For the 450 K sample, however, the Co/Cu/Co structure showed extensive disruption. The similarity in the depth-profiles for the 150 and 300 K samples indicates the sensitivity of the GMR to subtle structural differences. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Res Inst Tech Phys & Mat Sci, H-1525 Budapest, Hungary. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Menyhard, M (reprint author), Res Inst Tech Phys & Mat Sci, POB 49, H-1525 Budapest, Hungary. RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 20 TC 9 Z9 9 U1 3 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG 16 PY 2001 VL 180 IS 3-4 BP 315 EP 321 DI 10.1016/S0169-4332(01)00372-5 PG 7 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 465XE UT WOS:000170614600016 ER PT J AU Planet, WG Miller, AJ Horvath, K Nagatani, R Flynn, LE Hilsenrath, E Kondragunta, S Cebula, RP DeLand, MT AF Planet, WG Miller, AJ Horvath, K Nagatani, R Flynn, LE Hilsenrath, E Kondragunta, S Cebula, RP DeLand, MT TI Total ozone determinations from National Oceanic and Atmospheric Administration operational solar backscattered ultraviolet 2 instrument observations: An update SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NORTHERN-HEMISPHERE; TRENDS; SBUV; ACCURACY; TOMS AB Total ozone amounts have been derived from observations of the Solar Backscattered Ultraviolet 2 (SBUV/2) instruments on National Oceanic and Atmospheric Administration (NOAA) operational satellites since 1985. The data from the NOAA-9 instrument for the period 1985-1997 have been reprocessed using instrument characterizations based on in-orbit operation and comparisons with Shuttle Solar Backscattered Ultraviolet (SSBUV) observations. The data from the NOAA-11 satellite for the period 1989-1994 have also been reprocessed using mainly internal spacecraft information. The data from the NOAA-14 satellite for the period 1995-1998 have been reprocessed using complete instrument characterization. The NOAA-11 and NOAA-14 data for 1998 to the present, briefly discussed herein, are preliminary. The calibration adjustments used in the reprocessing of NOAA-9, NOAA-11, and NOAA-14 total ozone data are internal, with the exception of those derived from SSBUV analysis, and are independent of Dobson and Total Ozone Mapping Spectrometer (TOMS) total ozone measurements. The reprocessed data have been validated with ground-based Dobson spectrophotometer observations, and are compared to other sources of total column ozone amounts. The mean bias between NOAA-9 data and Dobson data is 1.9% +/- 0.6% over the 12-year record with a trend of 0.1% per year. The mean bias between NOAA-11 and Dobson data is 0.8% +/- 0.2% with a near-zero trend. The mean bias between NOAA-14 and Dobson data is 1.5% +/- 0.3% with a trend of 0.2% per year; the NOAA-14 calibration and characterization data for the period 1998 to the present are not yet fully analyzed. The methods used in the validations are discussed here, as are some reasons for the results. Finally, a recommendation is made for the use of a relatively continuous total ozone data set. C1 NOAA, Off Res & Applicat, Natl Environm Satellite Data & Informat Serv, Camp Springs, MD 20746 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, Climate Predict Ctr, Weather Serv, Camp Springs, MD 20746 USA. Res & Data Syst Corp, Greenbelt, MD USA. Raytheon Co, Informat Technol Serv, Lanham, MD USA. Raytheon Co, Sci Serv, Lanham, MD USA. RP Planet, WG (reprint author), 13115 14 St, Bowie, MD USA. RI Flynn, Lawrence/B-6321-2009; Kondragunta, Shobha/F-5601-2010 OI Flynn, Lawrence/0000-0001-6856-2614; Kondragunta, Shobha/0000-0001-8593-8046 NR 23 TC 6 Z9 6 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 16 PY 2001 VL 106 IS D15 BP 17471 EP 17478 DI 10.1029/2000JD900729 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 463BP UT WOS:000170457200028 ER PT J AU Behar, D Gonzalez, C Neta, P AF Behar, D Gonzalez, C Neta, P TI Reaction kinetics in ionic liquids: Pulse radiolysis studies of 1-butyl-3-methylimidazolium salts SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ELECTRON-TRANSFER; PEROXYL RADICALS; ORGANIC REDUCTANTS; RATE CONSTANTS; REDUCTION; ANIONS; POTENTIALS; IMIDAZOLE; ATOMS; CO2 AB Radiolysis of liquid 1-butyl-3-methylimidazolium (BMI+) salts leads to formation of several species with similar absorption spectra. To identify and characterize these species, experiments were carried out with BMI+ in solution under various conditions. BMI+ is reduced by e(aq)(-) very rapidly (k = 1.9 x 10(10) L mol(-1) s(-1)) but not by (CH3)(2)CO- radicals (k less than or equal to 1 x 10(5) L mol(-1) s(-1)). The reduced species exhibits an absorption peak at 323 nm (is an element of = 5.9 x 10(3) L mol(-1) cm(-1)). It decays via radical-radical reactions but does not react with O-2 or with methyl viologen. BMI+ reacts rapidly also with OH radicals (k = 3.7 x. 10(9) L mol(-1) s(-1)) to produce a mixture of isomeric OH(.)adducts. The spectrum of these adducts is similar to that of the reduced species, it exhibits a peak at 322 nm (is an element of = 2.5 x 10(3) L mol(-1) cm(-1)) but with a pronounced shoulder at 380 to 420 nm. The adducts. react with O-2 and with OH-. In the latter reaction they lose H+ to form a hydroxylated analogue of the electron adduct. Irradiation of liquid BMI+ salts produces BMI., BMI.2+, and various radical adducts. In the presence of CCl4 and O-2, CCl3O2. radicals are formed and these radicals oxidize Trolox and chlorpromazine with rate constants of (1 to 3) x 10(7) L mol(-1) s(-1). Even after correcting for the effect of viscosity, the rate constants are much lower than those determined in aqueous solutions and close to those measured in low-polarity organic solvents. The low rate constants in BMIPF6 and BMIBF4 probably indicate a high degree of ion-association in these ionic liquids. On the other hand, the activation energy of the reaction is close to that measured in aqueous solutions but higher than that in alcohols. This is discussed. in terms of highly structured solvent/solute domains. C1 NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Neta, P (reprint author), NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 34 TC 142 Z9 143 U1 1 U2 22 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 AUG 16 PY 2001 VL 105 IS 32 BP 7607 EP 7614 DI 10.1021/jp011405o PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 463TT UT WOS:000170493900014 ER PT J AU Gabelnick, AM Burnett, DJ Gland, JL Fischer, DA AF Gabelnick, AM Burnett, DJ Gland, JL Fischer, DA TI Molecular mechanisms of propyne oxidation on the Pt(111) surface: In situ soft X-ray studies in pressures of oxygen SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID TEMPERATURE-PROGRAMMED DESORPTION; ABSORPTION FINE-STRUCTURE; CATALYTIC-OXIDATION; HYDROCARBONS; COMBUSTION; PALLADIUM; ACETYLENE; PLATINUM; ETHYLENE; ALKENES AB Oxidation of preadsorbed propyne has been characterized on the Pt(111) surface in oxygen at pressures up to 0.009 Torr using fluorescence yield ultrasoft X-ray adsorption methods above the carbon K edge. A combination of temperature-programmed reaction spectroscopy (TPRS) and temperature-programmed fluorescence yield near edge spectroscopy (TP-FYNES) experiments indicating that similar oxidation pathways occur both for coadsorbed oxygen and pressures of oxygen. Soft X-ray spectroscopy indicates that propyne's pi system adsorbs nearly parallel to this surface with a saturation coverage of 1.45 x 10(15) C atoms/cm(2). Oxidation of small propyne coverages with coadsorbed oxygen results in simultaneous CO2 and H2O peaks at 320 and 420 K, as seen in TPRS. Oxidation of higher propyne coverages with coadsorbed oxygen results in a broad oxidation peak over the 350-420 K temperature range. Oxidation of a saturated propyne monolayer in oxygen pressures (TP-FYNES) results in a rapid decrease in carbon coverage over the same temperature range, suggesting similar mechanisms. Isothermal oxidation in oxygen atmospheres indicates that propyne oxidation is first-order in propyne coverage and has an activation energy of 17 kcal/mol for high coverages. Deviations from first-order behavior suggest that a second process may become important at lower coverages in oxygen atmospheres. Regardless of coverage and initial conditions, both TPRS and TP-FYNES indicate oxydehydrogenation and skeletal oxidation occur simultaneously and the oxidation proceeds with a fixed C3H4 stoichiometry. Taken together, these results give a molecular picture of propyne oxidation on the Pt(111) surface. C1 Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Chem Engn, Ann Arbor, MI 48109 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Gland, JL (reprint author), Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. NR 24 TC 10 Z9 10 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD AUG 16 PY 2001 VL 105 IS 32 BP 7748 EP 7754 DI 10.1021/jp011167x PG 7 WC Chemistry, Physical SC Chemistry GA 463TU UT WOS:000170494000020 ER PT J AU Feeney, M Brown, C Tsai, A Neumann, D Debenedetti, PG AF Feeney, M Brown, C Tsai, A Neumann, D Debenedetti, PG TI Incoherent quasi-elastic neutron scattering from fructose-water solutions SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SUPERCOOLED WATER; GLASS-TRANSITION; DYNAMICS; RELAXATION; SIMULATION; BEHAVIOR; SYSTEMS; SUGARS AB Quasi-elastic incoherent neutron scattering (QENS) was used to study the dynamics of 4, 29, and 60 wt % solutions of fructose in deionized water at 300 K. Both the jump-diffusion and stretched exponential models were used to analyze the data, enabling the determination of the structural relaxation rate 1/tau and the stretch exponent beta as functions of fructose concentration. The analysis of the neutron scattering data based on the jump-diffusion model is consistent with a transition from continuous to "hopping" or jump diffusion at 29 wt % fructose concentration observed in recent simulations of this same system. The analysis based on the stretched exponential model suggests that this change occurs at a higher fructose concentration. C1 Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Debenedetti, PG (reprint author), Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. RI Brown, Craig/B-5430-2009 OI Brown, Craig/0000-0002-9637-9355 NR 31 TC 19 Z9 19 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD AUG 16 PY 2001 VL 105 IS 32 BP 7799 EP 7804 DI 10.1021/jp010566p PG 6 WC Chemistry, Physical SC Chemistry GA 463TU UT WOS:000170494000027 ER PT J AU Kuznicki, SM Bell, VA Nair, S Hillhouse, HW Jacubinas, RM Braunbarth, CM Toby, BH Tsapatsis, M AF Kuznicki, SM Bell, VA Nair, S Hillhouse, HW Jacubinas, RM Braunbarth, CM Toby, BH Tsapatsis, M TI A titanosilicate molecular sieve with adjustable pores for size-selective adsorption of molecules SO NATURE LA English DT Article ID RIGID-UNIT MODES; PHASE-TRANSITION; ETS-10; FLEXIBILITY; RHO; TEMPERATURE; DIFFRACTION; FRAMEWORK AB Zeolites and related crystalline microporous oxides-tetrahedrally coordinated atoms covalently linked into a porous framework-are of interest for applications ranging from catalysis to adsorption and ion-exchange(1). In some of these materials (such as zeolite rho) adsorbates(2), ion-exchange, and dehydration and cation relocation(3,4) can induce strong framework deformations. Similar framework flexibility has to date not been seen in mixed octahedral/tetrahedral microporous framework materials, a newer and rapidly expanding class of molecular sieves(5-16). Here we show that the framework of the titanium silicate ETS-4, the first member of this class of materials(8), can be systematically contracted through dehydration at elevated temperatures to 'tune' the effective size of the pores giving access to the interior of the crystal. We show that this so-called 'molecular gate' effect can be used to tailor the adsorption properties of the materials to give size-selective adsorbents(17) suitable for commercially important separations of gas mixtures of molecules with similar size in the 4.0 to 3.0 Angstrom range, such as that of N-2/CH4, Ar/O-2 and N-2/O-2. C1 Engelhard Corp, Strateg Technol Grp, Iselin, NJ 08830 USA. Univ Massachusetts, Dept Chem Engn, Goessmann Lab 159, Amherst, MA 01003 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Kuznicki, SM (reprint author), Engelhard Corp, Strateg Technol Grp, 101 Wood Ave, Iselin, NJ 08830 USA. EM steve.kuznicki@engelhard.com RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 32 TC 342 Z9 348 U1 16 U2 163 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 16 PY 2001 VL 412 IS 6848 BP 720 EP 724 DI 10.1038/35089052 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 462ZB UT WOS:000170450200040 PM 11507636 ER PT J AU Fox, CG Chadwick, WW Embley, RW AF Fox, CG Chadwick, WW Embley, RW TI Direct observation of a submarine volcanic eruption from a sea-floor instrument caught in a lava flow SO NATURE LA English DT Article ID DE-FUCA RIDGE; AXIAL-VOLCANO; GROUND DEFORMATION; 1998 ERUPTION; MORPHOLOGY; DISCHARGE AB Our understanding of submarine volcanic eruptions has improved substantially in the past decade owing to the recent ability to remotely detect such events(1) and to then respond rapidly with synoptic surveys and sampling at the eruption site. But these data are necessarily limited to observations after the event(2). In contrast, the 1998 eruption of Axial volcano on the Juan de Fuca ridge(3,4) was monitored by in situ sea-floor instruments(5-7). One of these instruments, which measured bottom pressure as a proxy for vertical deformation of the sea floor, was overrun and entrapped by the 1998 lava flow. The instrument survived- being insulated from the molten lava by the solidified crust- and was later recovered. The data serendipitously recorded by this instrument reveal the duration, character and effusion rate of a sheet flow eruption on a mid-ocean ridge, and document over three metres of lava-flow inflation and subsequent drain-back. After the brief two-hour eruption, the instrument also measured gradual subsidence of 1.4 metres over the next several days, reflecting deflation of the entire volcano summit as magma moved into the adjacent rift zone. These findings are consistent with our understanding of submarine lava effusion, as previously inferred from seafloor observations, terrestrial analogues, and laboratory simulations(8-11). C1 Oregon State Univ, NOAA, Newport, OR 97365 USA. NOAA, PMEL, Newport, OR 97365 USA. RP Chadwick, WW (reprint author), Oregon State Univ, NOAA, 2115 SE OSU Dr, Newport, OR 97365 USA. EM chadwick@pmel.noaa.gov RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 20 TC 50 Z9 50 U1 1 U2 5 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 16 PY 2001 VL 412 IS 6848 BP 727 EP 729 DI 10.1038/35089066 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 462ZB UT WOS:000170450200042 PM 11507638 ER PT J AU McCabe, DC Gierczak, T Talukdar, RK Ravishankara, AR AF McCabe, DC Gierczak, T Talukdar, RK Ravishankara, AR TI Kinetics of the reaction OH plus CO under atmospheric conditions SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PRESSURE-DEPENDENCE; RATE-CONSTANT; MECHANISM; RADICALS; HO AB The rate coefficients for the reaction of OH with CO, k(1) at pressures of 50 - 750 Torr from 220 K to 400 K, in He, N-2, and air, are reported to be k(1) = (1.57 x 10(-13) + 3.54 x 10(.33) x [M]) cm(3) molecule(-1) s(-1), with [M] in molecule cm(-3), k(1) increases linearly with the bath gas number density; this increase is independent of temperature. k(1), at a given temperature and number density, is the same in N-2, dry air, and mixtures of O-2 (up to 49%) and N-2. The presence of water vapor does not significantly alter k(1) under atmospheric conditions. The uncertainty in our value of k(1) is +/- 15%, at the 95% confidence level, at any given [M] and temperature, which is smaller than the currently recommended uncertainty by a factor of four or more. Our k(1) values are compared with previous data and their atmospheric implications are discussed. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Warsaw Univ, Dept Chem, PL-02093 Warsaw, Poland. RP McCabe, DC (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80305 USA. RI TALUKDAR, RANAJIT/G-4530-2013; Ravishankara, Akkihebbal/A-2914-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 15 TC 24 Z9 24 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 2001 VL 28 IS 16 BP 3135 EP 3138 DI 10.1029/2000GL012719 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 461CV UT WOS:000170348100019 ER PT J AU Fujiwara, M Hasebe, F Shiotani, M Nishi, N Vomel, H Oltmans, SJ AF Fujiwara, M Hasebe, F Shiotani, M Nishi, N Vomel, H Oltmans, SJ TI Water vapor control at the tropopause by equatorial Kelvin waves observed over the Galapagos SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERE-TROPOSPHERE EXCHANGE AB Soundings of frost-point hygrometers, ozonesondes, and radiosondes at San Cristobal Island (0.9 degreesS, 89.6 degreesW) in September 1998 provide an observational evidence that equatorial Kelvin waves around the tropopause act as a dehydration pump for the stratosphere. During the downward-displacement phase of a Kelvin wave, dry and ozone-rich stratospheric air is transported into the upper troposphere. During the upward-displacement phase, on the other hand, higher specific-humidity air moves up in the tropopause region, but at the same time, this upward motion causes cooling of the air that limits the water vapor amount entering the stratosphere. Also, wave breaking contributes to the irreversible transport of ozone across the tropopause. Considering their omnipresence at the equatorial tropopause, we suggest that Kelvin waves may be one of the important agents for maintaining the dryness of the tropical lower stratosphere. C1 Hokkaido Univ, Sapporo, Hokkaido 060, Japan. Ibaraki Univ, Dept Environm Sci, Mito, Ibaraki 310, Japan. Kyoto Univ, Dept Earth & Planetary Sci, Kyoto 606, Japan. Univ Colorado, CIRES, Boulder, CO 80309 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. RP Fujiwara, M (reprint author), Kyoto Univ, Radio Sci Ctr Space & Atmosphere, RASC, Kyoto 6110011, Japan. RI Fujiwara, Masatomo/F-7852-2012 NR 12 TC 52 Z9 52 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 AUG 15 PY 2001 VL 28 IS 16 BP 3143 EP 3146 DI 10.1029/2001GL013310 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 461CV UT WOS:000170348100021 ER PT J AU Richard, EC Aikin, KC Andrews, AE Daube, BC Gerbig, C Wofsy, SC Romashkin, PA Hurst, DF Ray, EA Moore, FL Elkins, JW Deshler, T Toon, GC AF Richard, EC Aikin, KC Andrews, AE Daube, BC Gerbig, C Wofsy, SC Romashkin, PA Hurst, DF Ray, EA Moore, FL Elkins, JW Deshler, T Toon, GC TI Severe chemical ozone loss inside the Arctic Polar Vortex during winter 1999-2000 inferred from in-situ airborne measurements (vol 28, pg 2197, 2001) SO GEOPHYSICAL RESEARCH LETTERS LA English DT Correction C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO USA. Harvard Univ, Div Appl Sci, Cambridge, MA 02138 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Wyoming, Dept Atmospher Sci, Laramie, WY 82071 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Richard, EC (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80303 USA. RI Aikin, Kenneth/I-1973-2013; Gerbig, Christoph/L-3532-2013; Hurst, Dale/D-1554-2016 OI Gerbig, Christoph/0000-0002-1112-8603; Hurst, Dale/0000-0002-6315-2322 NR 1 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 AUG 15 PY 2001 VL 28 IS 16 BP 3167 EP 3167 DI 10.1029/2001GL013627 PG 1 WC Geosciences, Multidisciplinary SC Geology GA 461CV UT WOS:000170348100027 ER EF