FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Reed, BR Eberling, JL Mungas, D Weiner, MW Jagust, WJ AF Reed, BR Eberling, JL Mungas, D Weiner, MW Jagust, WJ TI Memory failure has different mechanisms in subcortical stroke and Alzheimer's disease SO ANNALS OF NEUROLOGY LA English DT Article ID ISCHEMIC VASCULAR DEMENTIA; CEREBRAL BLOOD-FLOW; FRONTAL-LOBE; HIPPOCAMPAL ATROPHY; SYSTEMS IMPAIRMENT; EPISODIC MEMORY; BRAIN ACTIVITY; TEMPORAL-LOBE; PET; INFARCTION AB Patients with extensive subcortical cerebrovascular disease may have impaired memory, often despite the absence of medial temporal or diencephalic strokes. In this group, episodic memory failure may arise from frontal lobe dysfunction based on disruption of frontosubcortical loops caused by lacunae. We tested this idea by studying cognitively impaired subcortical stroke (CIS) patients and Alzheimer's disease (AD) patients with [F-18]-fluorodeoxyglucose positron emission tomography using a continuous verbal memory task during the period of tracer uptake. Patients were matched on severity of cognitive impairment and overall memory task performance. As hypothesized, we found a double dissociation in the relations between metabolism and memory in these groups, such that memory in CIS (but not in AD) correlates with prefrontal lobe metabolism, whereas in AD (but not in CIS), memory correlates with left hippocampal and temporal lobe metabolism. Analysis of memory subscores showed that CIS patients made more errors on short-delay trials, which is consistent with working memory failure. It seems that different pathogenic mechanisms underlie episodic memory failure in subcortical cerebrovascular disease and AD. C1 Univ Calif Davis, Dept Neurol, Davis, CA 95616 USA. No Calif Hlth Care Syst, Dept Vet Affairs, Martinez, CA USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. Dept Vet Affairs Med Ctr, San Francisco, CA USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. RP Reed, BR (reprint author), Univ Calif Davis, Alzheimers Dis Ctr, 150 Muir Rd 127A, Martinez, CA 94553 USA. RI Mungas, Dan/E-6810-2011 FU NIA NIH HHS [AG10129, AG12435, P01 AG012435, P30 AG010129] NR 67 TC 50 Z9 52 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0364-5134 J9 ANN NEUROL JI Ann. Neurol. PD SEP PY 2000 VL 48 IS 3 BP 275 EP 284 DI 10.1002/1531-8249(200009)48:3<275::AID-ANA1>3.0.CO;2-C PG 10 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA 349BU UT WOS:000089024600001 PM 10976633 ER PT J AU Zavaljevski, N Shapiro, A AF Zavaljevski, N Shapiro, A TI A Markov chain Monte Carlo inverse procedure for radioactive contaminant transport in fractured rock: 1. Forward model SO ANNALS OF NUCLEAR ENERGY LA English DT Article ID TRANSFORM GALERKIN TECHNIQUE; MASS-TRANSPORT; MEDIA; SYSTEMS AB Safety assessment of high level radioactive waste repositories requires confidence in models for radioactive contaminant transport in fractured media. An approach for contaminant transport model testing is calibration based on large-scale laboratory experiments. This paper is the first of two papers in which the calibration of a two dimensional variable fracture network model for radioactive tracers is formulated as an inverse problem using a Bayes-Markov approach. This paper gives the framework for the inverse problem and describes a novel contaminant transport model appropriate for this problem. The subsequent paper presents the details of the algorithm for the inverse problem solution. The prior information for fracture aperture distribution is assumed in the form of Markov random fields (MRF). In particular, the class of auto-models has been successful in reproducing the connectivity in extreme values of fracture apertures, and experimentally observed flow channeling. A continuous model, conditional autoregressive model, and a discrete, auto-binomial model have been applied. The mathematical model for the contaminant transport in the discrete fracture network is based on the numerical inversion of the Laplace transform. This methodology is free of numerical dispersion, but requires a large number of terms to reconstruct very steep contaminant fronts. (C) 2000 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Cincinnati, Dept Mech Ind & Nucl Engn, Cincinnati, OH 45221 USA. RP Zavaljevski, N (reprint author), Argonne Natl Lab, Reactor Anal Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 40 TC 2 Z9 2 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0306-4549 J9 ANN NUCL ENERGY JI Ann. Nucl. Energy PD SEP PY 2000 VL 27 IS 14 BP 1285 EP 1302 DI 10.1016/S0306-4549(00)00029-3 PG 18 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 327CJ UT WOS:000087775100004 ER PT J AU Zavaljevski, N Shapiro, A AF Zavaljevski, N Shapiro, A TI A Markov chain Monte Carlo inverse procedure for radioactive contaminant transport in fractured rock: 2. Inverse model SO ANNALS OF NUCLEAR ENERGY LA English DT Article ID OPTIMIZATION; UNCERTAINTY; SYSTEMS AB Model calibration for radioactive contaminant transport in fractured rock has been formulated as an inverse problem and a solution proposed using a Bayesian approach. In particular, Markov random field (MRF) models have been proposed as a priori distribution functions for fracture apertures. The fracture reconstruction is based on the a posteriori distribution function simulation using a Markov chain Monte Carlo procedure. A two-level estimation-reconstruction algorithm has been developed. Oil the first level, the fracture apertures are reconstructed using simulated annealing (SA), with the Metropolis-Hastings dynamics. The MRF parameters are assumed known. On the second level, after several sweeps of the entire field using SA, the MRF parameters are updated using the method of pseudolikelihood. The competing models are finally compared using an asymptotic form of the Bayes factor. (C) 2000 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Cincinnati, Dept Mech Ind & Nucl Engn, Cincinnati, OH 45221 USA. RP Zavaljevski, N (reprint author), Argonne Natl Lab, Reactor Anal Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 24 TC 1 Z9 1 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0306-4549 J9 ANN NUCL ENERGY JI Ann. Nucl. Energy PD SEP PY 2000 VL 27 IS 14 BP 1303 EP 1318 DI 10.1016/S0306-4549(00)00030-X PG 16 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 327CJ UT WOS:000087775100005 ER PT J AU McArthur, JV Tuckfield, RC AF McArthur, JV Tuckfield, RC TI Spatial patterns in antibiotic resistance among stream bacteria: Effects of industrial pollution SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID BURKHOLDERIA PSEUDOMONAS CEPACIA; MERCURY-RESISTANCE; GENETIC DIVERSITY; LOTIC POPULATION; ASSOCIATION; ASSEMBLAGES; EVOLUTION; CONTINUUM; ANIMALS AB The spatial distribution of antibiotic resistance to streptomycin and kanamycin was examined in natural bacterial communities of two streams. The proportion of resistant bacteria was substantially higher (P < 0.05) in the midreaches of an industrially perturbed stream, but no such pattern was apparent in an undisturbed reference stream, The highest relative frequency of resistance was found at the confluence of a tributary draining a nuclear reactor and industrial complex. Antibiotic resistance increased with distance upstream from the confluence and was positively correlated (r(2) = 0.54, P = 0.023) with mercury concentrations in the sediments. When the data for two gears were compared, this pattern was stable for streptomycin resistance (paired t test, P < 0.05) but not for kanamycin resistance (P > 0,05), Our results imply that heavy metal pollution may contribute to increased antibiotic resistance through indirect selection. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29801 USA. Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP McArthur, JV (reprint author), Univ Georgia, Savannah River Ecol Lab, Drawer E, Aiken, SC 29801 USA. NR 27 TC 73 Z9 79 U1 2 U2 25 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD SEP PY 2000 VL 66 IS 9 BP 3722 EP 3726 DI 10.1128/AEM.66.9.3722-3726.2000 PG 5 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 350NZ UT WOS:000089109200010 PM 10966382 ER PT J AU Savage, KS Tingle, TN O'Day, PA Waychunas, GA Bird, DK AF Savage, KS Tingle, TN O'Day, PA Waychunas, GA Bird, DK TI Arsenic speciation in pyrite and secondary weathering phases, Mother Lode Gold District, Tuolumne County, California SO APPLIED GEOCHEMISTRY LA English DT Article ID MULTIPLE-SCATTERING CALCULATIONS; RAY-ABSORPTION SPECTROSCOPY; MINE TAILINGS; JAROSITE PRECIPITATION; LACUSTRINE SEDIMENTS; IRON OXYHYDROXIDES; CONTAMINATED SOILS; CRYSTAL-CHEMISTRY; STABLE ISOTOPE; FINE-STRUCTURE AB Arsenian pyrite, formed during Cretaceous gold mineralization, is the primary source of As along the Melones fault zone in the southern Mother Lode Gold District of California. Mine tailings and associated weathering products from partially submerged inactive gold mines at Don Pedro Reservoir, on the Tuolumne River, contain similar to 20-1300 ppm As. The highest concentrations are in weathering crusts from the Clio mine and nearby outcrops which contain goethite or jarosite. As is concentrated up to 2154 ppm in the fine-grained (< 63 mu m) fraction of these Fe-rich weathering products. Individual pyrite grains in albite-chlorite schists of the Clio mine tailings contain an average of 1.2 wt.% As. Pyrite grains are coarsely zoned, with local As concentrations ranging from similar to 0 to 5 wt.%. Electron microprobe, transmission electron microscope, and extended X-ray absorption fine-structure spectroscopy (EXAFS) analyses indicate that As substitutes for S in pyrite and is not present as inclusions of arsenopyrite or other As-bearing phases. Comparison with simulated EXAFS spectra demonstrates that As atoms are locally clustered in the pyrite lattice and that the unit cell of arsenian pyrite is expanded by similar to 2.6% relative to pure pyrite. During weathering, clustered substitution of As into pyrite may be responsible for accelerating oxidation, hydrolysis, and dissolution of arsenian pyrite relative to pure pyrite in weathered tailings. Arsenic K-edge EXAFS analysis of the fine-grained Fe-rich weathering products are consistent with corner;sharing between As(V) tetrahedra and Fe(III)-octahedra. Determinations of nearest-neighbor distances and atomic identities, generated from least-squares fitting algorithms to spectral data, indicate that arsenate tetrahedra are sorbed on goethite mineral surfaces but substitute for SO4 in jarosite. Erosional transport of As-bearing goethite and jarosite to Don Pedro Reservoir increases the potential for As mobility and bioavailability by desorption or dissolution. Both the substrate minerals and dissolved As species are expected to respond to seasonal changes in lake chemistry caused by thermal stratification and turnover within the monomictic Don Pedro Reservoir. Arsenic is predicted to be most bioavailable and toxic in the reservoir's summer hypolimnion. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Savage, KS (reprint author), Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. NR 69 TC 247 Z9 262 U1 8 U2 68 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0883-2927 J9 APPL GEOCHEM JI Appl. Geochem. PD SEP PY 2000 VL 15 IS 8 BP 1219 EP 1244 DI 10.1016/S0883-2927(99)00115-8 PG 26 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 322JG UT WOS:000087506000009 ER PT J AU Koch, JA Presta, RW Sacks, RA Zacharias, RA Bliss, ES Dailey, MJ Feldman, M Grey, AA Holdener, FR Salmon, JT Seppala, LG Toeppen, JS Van Atta, L Van Wonterghem, BM Whistler, WT Winters, SE Woods, BW AF Koch, JA Presta, RW Sacks, RA Zacharias, RA Bliss, ES Dailey, MJ Feldman, M Grey, AA Holdener, FR Salmon, JT Seppala, LG Toeppen, JS Van Atta, L Van Wonterghem, BM Whistler, WT Winters, SE Woods, BW TI Experimental comparison of a Shack-Hartmann sensor and a phase-shifting interferometer for large-optics metrology applications SO APPLIED OPTICS LA English DT Article ID WAVE-FRONT SENSOR; PERFORMANCE AB We performed a direct side-by-side comparison of a Shack-Hartmann wave-front sensor and a phase-shifting interferometer for the purpose of characterizing large optics. An expansion telescope of our own design allowed us to measure the surface figure of a 400-mm-square mirror with both instruments simultaneously. The Shack-Hartmann sensor produced data that closely matched the interferometer data over spatial scales appropriate for the lenslet spacing, and much of the <20-nm rms systematic difference between the two measurements was due to diffraction artifacts that were present in the interferometer data but not in the Shack-Hartmann sensor data. The results suggest that Shack-Hartmann sensors could replace phase-shifting interferometers for many applications, with particular advantages for large-optic metrology. (C) 2000 Optical Society of America OCIS codes: 120.3180, 120.3930, 010.7060. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Koch, JA (reprint author), Lawrence Livermore Natl Lab, POB 808,L-481, Livermore, CA 94551 USA. EM koch1@llnl.gov NR 7 TC 38 Z9 39 U1 0 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 SEP 1 PY 2000 VL 39 IS 25 BP 4540 EP 4546 DI 10.1364/AO.39.004540 PG 7 WC Optics SC Optics GA 349BT UT WOS:000089024500010 PM 18350042 ER PT J AU Martin, M Cheng, MD AF Martin, M Cheng, MD TI Detection of chromium aerosol using time-resolved laser-induced plasma spectroscopy SO APPLIED SPECTROSCOPY LA English DT Article DE laser-induced plasma spectroscopy; aerosol; chromium; laser-induced breakdown spectroscopy ID INDUCED BREAKDOWN SPECTROSCOPY; WAVELENGTH DEPENDENCE; DROPLETS; SPECTRA; PARTICLES AB Time-resolved laser-induced plasma spectroscopy (LIPS) has been used as a tool for the detection of chromium in aerosol. In this article, LIPS has been used to achieve the lowest limits of detection for chromium (400 ng/dscm) in droplets. A comparison with other LIPS instruments and inductively coupled plasma atomic emission spectroscopy (ICP-AES) shows that the limits of detection for chromium metal in aerosol range from 12 to 60 mu g/dscm and 200 ng/dscm for LIPS and ICP-AES, respectively. We have studied the effects of laser wavelength, excitation energy, and optimum spectrometer delay time to optimize these low limits of detection. A Nd:YAG laser with output wavelengths of 1064, 532, and 266 nm has been used to study the effects of wavelength on laser energy and aerosol interactions-specifically, plasma initiation and efficiency of ionization in the detection of elemental species. Measured time-resolved spectra are used to establish the most appropriate time delay producing an optimum signal-to-background ratio. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Oak Ridge Inst Sci & Technol, Oak Ridge, TN 37831 USA. RP Cheng, MD (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Martin, Madhavi/A-5268-2011; Cheng, Meng-Dawn/C-1098-2012; OI Martin, Madhavi/0000-0002-6677-2180; Cheng, Meng-Dawn/0000-0003-1407-9576 NR 16 TC 47 Z9 47 U1 2 U2 12 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD SEP PY 2000 VL 54 IS 9 BP 1279 EP 1285 DI 10.1366/0003702001951192 PG 7 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 360QD UT WOS:000089678000005 ER PT J AU Haaland, DM Chambers, WB Keenan, MR Melgaard, DK AF Haaland, DM Chambers, WB Keenan, MR Melgaard, DK TI Multi-window classical least-squares multivariate calibration methods for quantitative ICP-AES analyses SO APPLIED SPECTROSCOPY LA English DT Article DE inductively coupled plasma/atomic emission; ICPAES; classical least-squares; CLS; multi-window classical least-squares; MWCLS; quantitative elemental spectroscopy; multivariate analysis ID INDUCTIVELY-COUPLED PLASMA; OPTICAL-EMISSION-SPECTROMETRY; DEVICE DETECTOR; MULTICOMPONENT SAMPLES; DETECTION LIMITS; SPECTRA; OES; INTERFERENCES; TUTORIAL; FIGURES AB The advent of inductively coupled plasma atomic emission spectrometers (ICP-AES) equipped with charge-coupled device (CCD) detector arrays allows the application of multivariate calibration methods to the quantitative analysis of spectral data. We have applied classical least-squares (CLS) methods to the analysis of a variety of samples containing up to 12 elements plus an internal standard. The elements included in the calibration models were Ag, Al, As, Au, Cd, Cr, Cu, Fe, Ni, Pb, Pd, and Se. By performing the CLS analysis separately in each of 46 spectral windows and by pooling the CLS concentration results for each element in all windows in a statistically efficient manner, we have been able to significantly improve the accuracy and precision of the ICP-AES analyses relative to the univariate and single-window multivariate methods supplied with the spectrometer. This new multi-window CLS (MWCLS) approach simplifies the analyses by providing a single concentration determination for each element from all spectral windows. Thus, the analyst does not have to perform the tedious task of reviewing the results from each window in an attempt to decide the correct value among discrepant analyses in one or more windows for each element. Furthermore, it is not necessary to construct a spectral correction model for each window prior to calibration and analysis. When one or more interfering elements were present, the new MWCLS method was able to reduce prediction errors compared to the single-window multivariate and univariate predictions. The MWCLS detection limits in the presence of multiple interferences are 15 ng/g (i.e., 15 ppb) or better for each element. In addition, errors with the new method are only slightly inflated when only a single target element is included in the calibration (i.e., knowledge of all other elements is excluded during calibration). The MWCLS method is found to be vastly superior to partial least-squares (PLS) in this case of limited numbers of calibration samples. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Haaland, DM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 27 TC 13 Z9 13 U1 1 U2 2 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD SEP PY 2000 VL 54 IS 9 BP 1291 EP 1302 DI 10.1366/0003702001951219 PG 12 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 360QD UT WOS:000089678000007 ER PT J AU Haaland, DM Melgaard, DK AF Haaland, DM Melgaard, DK TI New prediction-augmented classical least-squares (PACLS) methods: Application to unmodeled interferents SO APPLIED SPECTROSCOPY LA English DT Article DE classical least-squares; CLS; prediction-augmenter classical least-squares; PACLS; multivariate calibration; near-infrared spectroscopy; aqueous solutions; temperature calibration; spectrometer drift ID FT-IR SPECTRA; MULTIVARIATE CALIBRATION; MULTICOMPONENT SAMPLES; INFRARED-SPECTROSCOPY; QUANTITATIVE-ANALYSIS AB A significant improvement to the classical least-squares (CLS) multivariate analysis method has been developed. The new method, called prediction-augmented classical least-squares (PACLS), removes the restriction for CLS that all interfering spectral species must be known and their concentrations included during the calibration. We demonstrate that PACLS can correct inadequate CLS models if spectral components left out of the calibration can be identified and if their "spectral shapes" can be derived and added during a PACLS prediction step. The new PACLS method is demonstrated for a system of dilute aqueous solutions containing urea, creatinine, and NaCl analytes with and without temperature variations. We demonstrate that if CLS calibrations are performed with only a single analyte's concentrations, then there is little, if any, prediction ability. However, if pure-component spectra of analytes left out of the calibration are independently obtained and added during PACLS prediction, then the CLS prediction ability is corrected and predictions become comparable to that of a CLS calibration that contains all analyte concentrations. It is also demonstrated that constant-temperature CLS models can be used to predict variable-temperature data by employing the PACLS method augmented by the spectral shape of a temperature change of the water solvent. In this case, PACLS can also be used to predict sample temperature with a standard error of prediction of 0.07 degrees C even though the calibration data did not contain temperature variations. The PACLS method is also shown to be capable of modeling system drift to maintain a calibration in the presence of spectrometer drift. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Haaland, DM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 26 TC 55 Z9 56 U1 0 U2 4 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD SEP PY 2000 VL 54 IS 9 BP 1303 EP 1312 DI 10.1366/0003702001951228 PG 10 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 360QD UT WOS:000089678000008 ER PT J AU Schoonover, JR Saab, A Bridgewater, JS Havrilla, GJ Zugates, CT Treado, PJ AF Schoonover, JR Saab, A Bridgewater, JS Havrilla, GJ Zugates, CT Treado, PJ TI Raman/SEM chemical imaging of a residual gallium phase in a mixed oxide feed surrogate SO APPLIED SPECTROSCOPY LA English DT Article DE chemical imaging; Raman imaging; liquid crystal tunable filter; LCTF; SERI; integrated spectroscopy; MOX; CeO2; gallium ID PEROVSKITE STRUCTURE; SPECTRA; FUEL AB An integrated analytical approach, which combines elemental [scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS)] and molecular (Raman) chemical imaging techniques, has been utilized for the characterization of a residual phase of gallium in mixed oxide (MOX) surrogate material. Surrogate MOX materials are comprised of CeO2 in place of PuO2. In real MOX materials, PuO2 is mixed with UO2 as a commercial fuel source. A Ga phase remains in the surrogate sample following reductive heating experiments designed to explore the removal of gallium from weapons-grade plutonium. The SEM/EDS data reveal the concentration of Ga within the grain boundaries of the sample and a distribution of Ce and O throughout the sample matrix. Molecular analysis provided by Raman chemical matrix imaging correlates with the SEM/EDS elemental imaging results. Specifically, the Raman data suggest that the matrix is comprised of CeO2 and grain boundaries are a mixed phase comprised of CeO2 with a form of Ga, most likely a CeGaO3 perovskite phase ha,iug a cubic structure. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Nucl Mat Technol Div, Los Alamos, NM 87545 USA. ChemIcon Inc, Pittsburgh, PA 15208 USA. RP Schoonover, JR (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 20 TC 12 Z9 14 U1 0 U2 3 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD SEP PY 2000 VL 54 IS 9 BP 1362 EP 1371 DI 10.1366/0003702001951048 PG 10 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 360QD UT WOS:000089678000015 ER PT J AU Johnson, RL Moursund, RA AF Johnson, RL Moursund, RA TI Evaluation of juvenile salmon behavior at Bonneville Dam, Columbia River, using a multibeam technique SO AQUATIC LIVING RESOURCES LA English DT Article; Proceedings Paper CT 2nd International Conference on Shallow Water Fisheries Sonar CY SEP 07-09, 1999 CL UNIV WASHINGTON, SEATTLE, WASHINGTON SP IRD, BioSonics, SIMRAD, NOAA, Natl Marine Fisheries Serv, Sonar Data, Jasco Res Ltd, HTI HO UNIV WASHINGTON DE multibeam sonar; hydroacoustics; smolt; fish behavior; fish behavior; hydropower dams; fish tracking; three-dimensional visualization ID SONAR AB In recent years, with increased effort to bypass and guide fragile stocks of juvenile salmon in the Columbia Basin past hydroelectric projects, it has been increasingly important to obtain fine-scale fish behavior data in a non-intrusive manner. The Dual-Head Multibeam Sonar is an emerging technology for fisheries applications that addresses that requirement. It has two principal advantages over traditional hydroacoustic techniques: 1) it allows for simultaneous large-volume coverage of a region of interest, and 2) it affords three-dimensional tracking capability. The use of Dual Head Multibeam Sonar in this study resulted in an unprecedented insight into fine-scale smolt behavior upstream of a prototype surface collector at the Bonneville Dam first powerhouse in 1998. Our results indicated that outmigrant juvenile salmon had an increased likelihood of milling or holding. This discovery will lead to better design criteria for future bypass and collector systems. Future fisheries multibeam sonar systems will likely be fully integrated systems with built-in real-time tracking capability. These systems may be used to track targets relative to physical guidance structures or other behavior-modifying stimuli such as light, turbulent flow, electrical/magnetic fields, or low-frequency sound and vibration. The combination of fine-scale fish behavior data and environmental parameters will yield better design criteria for the safe passage of listed or endangered species of Pacific salmon. (C) 2000 Ifremer/CNRS/INRA/IRD/Cemagref/Editions scientifiques et medicales Elsevier SAS. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Johnson, RL (reprint author), Pacific NW Natl Lab, POB 999,K6-85,Battelle Blvd, Richland, WA 99352 USA. NR 14 TC 14 Z9 15 U1 3 U2 10 PU GAUTHIER-VILLARS/EDITIONS ELSEVIER PI PARIS PA 23 RUE LINOIS, 75015 PARIS, FRANCE SN 0990-7440 J9 AQUAT LIVING RESOUR JI Aquat. Living Resour. PD SEP-OCT PY 2000 VL 13 IS 5 BP 313 EP 318 DI 10.1016/S0990-7440(00)01088-3 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 388ZU UT WOS:000166213700008 ER PT J AU Bedau, MA McCaskill, JS Packard, NH Rasmussen, S Adami, C Green, DG Ikegami, T Kaneko, K Ray, TS AF Bedau, MA McCaskill, JS Packard, NH Rasmussen, S Adami, C Green, DG Ikegami, T Kaneko, K Ray, TS TI Open problems in artificial life SO ARTIFICIAL LIFE LA English DT Article; Proceedings Paper CT 7th International Conference on Artificial Life CY 2000 CL PORTLAND, OREGON SP Reed Coll, Intel Corp DE artificial life; evolution; self-organization; emergence; self-replication; autopoeisis; digital life; artificial chemistry; selection; evolutionary learning; ecosystems; biosystems; astrobiology; evolvable hardware; dynamical hierarchies; origin of life; simulation; cultural evolution; information theory ID EVOLUTION AB This article lists fourteen open problems in artificial life, each of which is a grand challenge requiring a major advance on a fundamental issue for its solution. Each problem is briefly explained, and, where deemed helpful, some promising paths to it solution are indicated. C1 Reed Coll, Portland, OR 97202 USA. German Natl Res Ctr Informat Technol, D-53754 Birlinghoven, Germany. Predict Co, Santa Fe, NM USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CALTECH, Pasadena, CA 91125 USA. Charles Sturt Univ, Sch Environm & Informat Sci, Albury, NSW 2640, Australia. Univ Tokyo, Grad Sch Arts & Sci, Inst Phys, Meguro Ku, Tokyo 153, Japan. Univ Tokyo, Dept Pure & Appl Sci, Meguro ku, Tokyo 153, Japan. Univ Oklahoma, Dept Zool, Norman, OK 73019 USA. RP Bedau, MA (reprint author), Reed Coll, 3202 SE Woodstock Blvd, Portland, OR 97202 USA. RI Adami, Christoph/A-5181-2009; Adami, Christoph/A-9675-2011; McCaskill, John/A-9521-2015; OI Adami, Christoph/0000-0002-2915-9504; McCaskill, John/0000-0002-3408-7357; Green, David/0000-0002-9488-6601 NR 18 TC 93 Z9 98 U1 23 U2 129 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 1064-5462 J9 ARTIF LIFE JI Artif. Life PD FAL PY 2000 VL 6 IS 4 BP 363 EP 376 DI 10.1162/106454600300103683 PG 14 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA 420MM UT WOS:000168008800007 PM 11348587 ER PT J AU Khalighi, B Fischer, S AF Khalighi, B Fischer, S TI Environmental impacts of automotive refrigerants SO ASHRAE JOURNAL LA English DT Article C1 GM Corp, R&D Ctr, Warren, MI 48090 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Khalighi, B (reprint author), GM Corp, R&D Ctr, Warren, MI 48090 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEATING REFRIGERATING AIR-CONDITIONING ENG, INC, PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA SN 0001-2491 J9 ASHRAE J JI ASHRAE J. PD SEP PY 2000 VL 42 IS 9 BP 50 EP 51 PG 2 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 355KM UT WOS:000089384900013 ER PT J AU Fan, XH White, RL Davis, M Becker, RH Strauss, MA Haiman, Z Schneider, DP Gregg, MD Gunn, JE Knapp, GR Lupton, RH Anderson, JE Anderson, SF Annis, J Bahcall, NA Boroski, WN Brunner, RJ Chen, B Connolly, AJ Csabai, I Doi, M Fukugita, M Hennessy, GS Hindsley, RB Ichikawa, T Ivezic, Z Loveday, J Meiksin, A McKay, TA Munn, JA Newberg, HJ Nichol, R Okamura, S Pier, JR Sekiguchi, M Shimasaku, E Stoughton, C Szalay, AS Szokoly, GP Thakar, AR Vogeley, MS York, DG AF Fan, XH White, RL Davis, M Becker, RH Strauss, MA Haiman, Z Schneider, DP Gregg, MD Gunn, JE Knapp, GR Lupton, RH Anderson, JE Anderson, SF Annis, J Bahcall, NA Boroski, WN Brunner, RJ Chen, B Connolly, AJ Csabai, I Doi, M Fukugita, M Hennessy, GS Hindsley, RB Ichikawa, T Ivezic, Z Loveday, J Meiksin, A McKay, TA Munn, JA Newberg, HJ Nichol, R Okamura, S Pier, JR Sekiguchi, M Shimasaku, E Stoughton, C Szalay, AS Szokoly, GP Thakar, AR Vogeley, MS York, DG TI The discovery of a luminous z=5.80 quasar from the Sloan Digital Sky Survey SO ASTRONOMICAL JOURNAL LA English DT Review DE intergalactic medium; quasars : absorption lines; quasars : emission lines; quasars : individual (SDSSp J104433.04-012502.2) ID SURVEY COMMISSIONING DATA; HIGH-REDSHIFT QUASARS; LYMAN-ALPHA FOREST; SPECTROPHOTOMETRIC STANDARDS; COSMOLOGICAL CONSTANT; BLACK-HOLE; GALAXY; EVOLUTION; OBJECTS; SYSTEM AB We present observations of SDSSp J104433.04-012502.2, a luminous quasar at z = 5.80 discovered from Sloan Digital Sky Survey (SDSS) multicolor imaging data. This object was selected as an i'-band dropout object, with i* = 21.8 +/- 0.2 and z* = 19.2 +/- 0.1. It has an absolute magnitude M(1450) = -27.2 (H(0) = 50 km s(-1) Mpc(-1), q(0) = 0.5). The spectrum shows a strong and broad Ly alpha emission line, strong Ly alpha forest absorption lines with a mean continuum decrement D(A) = 0.91 and a Lyman limit system at z = 5.72. The spectrum also shows strong O I and Si rv emission lines similar to those of quasars at z less than or similar to 5, suggesting that these metals were produced at a redshift beyond 6. The lack of a Gunn-Peterson trough in the spectrum indicates that the universe is already highly ionized at z similar to 5.8. Using a high-resolution spectrum in the Ly alpha forest region, we place a conservative upper limit on the optical depth because of the Gunn-Peterson effect of tau < 0.5 in regions of minimum absorption. The Ly alpha forest absorption in this object is much stronger than that in quasars at z less than or similar to 5. The object is unresolved in a deep image with excellent seeing, implying that it is unlensed. The black hole mass of this quasar is similar to 3 x 10(9) M. if we assume no lensing amplification and that it is radiating at the Eddington luminosity, implying that it resides in a very massive dark matter halo. The discovery of one quasar at M(1450) < -27 in a survey area of 600 deg(2) is consistent with an extrapolation of the observed luminosity function at lower redshifts. The abundance and evolution of such quasars can provide sensitive tests for models of quasar and galaxy formation. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, IGPP, Livermore, CA 95616 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Univ Tokyo, Sch Sci, Dept Astron, Tokyo 1130033, Japan. Univ Tokyo, Sch Sci, Res Ctr Early Universe, Tokyo 1130033, Japan. Univ Tokyo, Inst Cosm Ray Res, Tokyo 1888502, Japan. Inst Adv Study, Princeton, NJ 08540 USA. USN Observ, Washington, DC 20392 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Tohoku Univ, Inst Astron, Sendai, Miyagi 9808578, Japan. Univ Sussex, Ctr Astron, Brighton BN1 9QJ, E Sussex, England. Univ Edinburgh, Astron Inst, Edinburgh EH9 3HJ, Midlothian, Scotland. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Fan, XH (reprint author), Princeton Univ Observ, Princeton, NJ 08544 USA. RI Csabai, Istvan/F-2455-2012; McKay, Timothy/C-1501-2009; OI McKay, Timothy/0000-0001-9036-6150; Meiksin, Avery/0000-0002-5451-9057; Csabai, Istvan/0000-0001-9232-9898 NR 68 TC 205 Z9 205 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2000 VL 120 IS 3 BP 1167 EP 1174 DI 10.1086/301534 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360LX UT WOS:000089670300001 ER PT J AU Fischer, P McKay, TA Sheldon, E Connolly, A Stebbins, A Frieman, JA Jain, B Joffre, M Johnston, D Bernstein, G Annis, J Bahcall, NA Brinkmann, J Carr, MA Csabai, I Gunn, JE Hennessy, GS Hindsley, RB Hull, C Ivezic, Z Knapp, GR Limmongkol, S Lupton, RH Munn, JA Nash, T Newberg, HJ Owen, R Pier, JR Rockosi, CM Schneider, DP Smith, JA Stoughton, C Szalay, AS Szokoly, GP Thakar, AR Vogeley, MS Waddell, P Weinberg, DH York, DG AF Fischer, P McKay, TA Sheldon, E Connolly, A Stebbins, A Frieman, JA Jain, B Joffre, M Johnston, D Bernstein, G Annis, J Bahcall, NA Brinkmann, J Carr, MA Csabai, I Gunn, JE Hennessy, GS Hindsley, RB Hull, C Ivezic, Z Knapp, GR Limmongkol, S Lupton, RH Munn, JA Nash, T Newberg, HJ Owen, R Pier, JR Rockosi, CM Schneider, DP Smith, JA Stoughton, C Szalay, AS Szokoly, GP Thakar, AR Vogeley, MS Waddell, P Weinberg, DH York, DG CA SDSS Collaboration TI Weak lensing with Sloan Digital Sky Survey commissioning data: The galaxy-mass correlation function to 1 h(-l) Mpc SO ASTRONOMICAL JOURNAL LA English DT Article DE dark matter; galaxies : fundamental parameters; galaxies : halos; gravitational lensing; large-scale structure of universe ID HUBBLE DEEP FIELD; PHOTOMETRY; REDSHIFTS; EVOLUTION; SPACE AB We present measurements of galaxy-galaxy weak lensing from 225 deg(2) of early commissioning imaging data from the Sloan Digital Sky Survey (SDSS). We measure a mean tangential shear around a stacked sample of foreground galaxies in three bandpasses (g', r', and i') out to angular radii of 600", detecting the shear signal at very high statistical significance. The shear profile is well described by a power law gamma(T) = gamma(TO)(1/theta)", with best-fit slope of eta = 0.7-1.1 (95% confidence). In the range theta = 10"-600", the mean tangential shear is approximately 6 +/- 1 x 10(-4) in all three bands. A variety of rigorous tests demonstrate the reality of the gravitational lensing signal and confirm the uncertainty estimates. In particular, we obtain shear measurements consistent with zero when we rotate the background galaxies by 45 degrees, replace foreground galaxies with random points, or replace foreground galaxies with bright stars. We interpret our results by assuming that all matter correlated with galaxies belongs to the galaxies. We model the mass distributions of the foreground glaxies, which have a mean luminosity [L(theta < 5")] = 8.7 +/- 0.7 x 10(9) h(-2) L-g'circle dot,1.4 +/- 0.12 x 10(10) h(-2) L-r'circle dot, 1.8 +/- 0.14 x 10(10) h(-2) L-i'circle dot, as approximately isothermal spheres characterized by a velocity dispersion a, and a truncation radius s. The velocity dispersion is constrained to be sigma(v) = 150-190 km s(-1) at 95% confidence (145-195 km s(-1) including systematic uncertainties), consistent with previous determinations but with smaller error bars. Our detection of shear at large angular radii sets a 95% confidence lower limit s > 140", corresponding to a physical radius of 260 h(-1) kpc, implying that the dark halos of typical luminous galaxies extend to very large radii. However, it is likely that this is being systematically biased to large value by diffuse matter in the halos of groups and clusters of galaxies. We also present a preliminary determination of the galaxy-mass correlation function, finding a correlation length similar to the galaxy autocorrelation function and consistency with a low matter density universe with modest bias. The full SDSS will cover an area 44 times larger and provide spectroscopic redshifts for the foreground galaxies, making it possible to improve greatly the precision of these constraints, to measure additional parameters such as halo shape and halo concentration, and to measure the properties of dark matter halos separately for many different classes of galaxies. C1 Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Apache Point Observ, Sunspot, NM 88349 USA. Eotvos Lorand Univ, Dept Phys Complex Syst, H-1117 Budapest, Hungary. USN Observ, Washington, DC 20392 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. RP Fischer, P (reprint author), Univ Toronto, Dept Astron, 60 St George St, Toronto, ON M5S 3H8, Canada. RI Csabai, Istvan/F-2455-2012; McKay, Timothy/C-1501-2009; OI McKay, Timothy/0000-0001-9036-6150; Csabai, Istvan/0000-0001-9232-9898 NR 45 TC 149 Z9 150 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2000 VL 120 IS 3 BP 1198 EP 1208 DI 10.1086/301540 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360LX UT WOS:000089670300004 ER PT J AU York, DG Adelman, J Anderson, JE Anderson, SF Annis, J Bahcall, NA Bakken, JA Barkhouser, R Bastian, S Berman, E Boroski, WN Bracker, S Briegel, C Briggs, JW Brinkmann, J Brunner, R Burles, S Carey, L Carr, MA Castander, FJ Chen, B Colestock, PL Connolly, AJ Crocker, JH Csabai, I Czarapata, PC Davis, JE Doi, M Dombeck, T Eisenstein, D Ellman, N Elms, BR Evans, ML Fan, XH Federwitz, GR Fiscelli, L Friedman, S Frieman, JA Fukugita, M Gillespie, B Gunn, JE Gurbani, VK de Haas, E Haldeman, M Harris, FH Hayes, J Heckman, TM Hennessy, GS Hindsley, RB Holm, S Holmgren, DJ Huang, CH Hull, C Husby, D Ichikawa, S Ichikawa, T Ivezic, Z Kent, S Kim, RSJ Kinney, E Klaene, M Kleinman, AN Kleinman, S Knapp, GR Korienek, J Kron, RG Kunszt, PZ Lamb, DQ Lee, B Leger, RF Limmongkol, S Lindenmeyer, C Long, DC Loomis, C Loveday, J Lucinio, R Lupton, RH MacKinnon, B Mannery, EJ Mantsch, PM Margon, B McGehee, P McKay, TA Meiksin, A Merelli, A Monet, DG Munn, JA Narayanan, VK Nash, T Neilsen, E Neswold, R Newberg, HJ Nichol, RC Nicinski, T Nonino, M Okada, N Okamura, S Ostriker, JP Owen, R Pauls, AG Peoples, J Peterson, RL Petravick, D Pier, JR Pope, A Pordes, R Prosapio, A Rechenmacher, R Quinn, TR Richards, GT Richmond, MW Rivetta, CH Rockosi, CM Ruthmansdorfer, K Sandford, D Schlegel, DJ Schneider, DP Sekiguchi, M Sergey, G Shimasaku, K Siegmund, WA Smee, S Smith, JA Snedden, S Stone, R Stoughton, C Strauss, MA Stubbs, C SubbaRao, M Szalay, AS Szapudi, I Szokoly, GP Thakar, AR Tremonti, C Tucker, DL Uomoto, A Berk, DV Vogeley, MS Waddell, P Wang, SI Watanabe, M Weinberg, DH Yanny, B Yasuda, N AF York, DG Adelman, J Anderson, JE Anderson, SF Annis, J Bahcall, NA Bakken, JA Barkhouser, R Bastian, S Berman, E Boroski, WN Bracker, S Briegel, C Briggs, JW Brinkmann, J Brunner, R Burles, S Carey, L Carr, MA Castander, FJ Chen, B Colestock, PL Connolly, AJ Crocker, JH Csabai, I Czarapata, PC Davis, JE Doi, M Dombeck, T Eisenstein, D Ellman, N Elms, BR Evans, ML Fan, XH Federwitz, GR Fiscelli, L Friedman, S Frieman, JA Fukugita, M Gillespie, B Gunn, JE Gurbani, VK de Haas, E Haldeman, M Harris, FH Hayes, J Heckman, TM Hennessy, GS Hindsley, RB Holm, S Holmgren, DJ Huang, CH Hull, C Husby, D Ichikawa, S Ichikawa, T Ivezic, Z Kent, S Kim, RSJ Kinney, E Klaene, M Kleinman, AN Kleinman, S Knapp, GR Korienek, J Kron, RG Kunszt, PZ Lamb, DQ Lee, B Leger, RF Limmongkol, S Lindenmeyer, C Long, DC Loomis, C Loveday, J Lucinio, R Lupton, RH MacKinnon, B Mannery, EJ Mantsch, PM Margon, B McGehee, P McKay, TA Meiksin, A Merelli, A Monet, DG Munn, JA Narayanan, VK Nash, T Neilsen, E Neswold, R Newberg, HJ Nichol, RC Nicinski, T Nonino, M Okada, N Okamura, S Ostriker, JP Owen, R Pauls, AG Peoples, J Peterson, RL Petravick, D Pier, JR Pope, A Pordes, R Prosapio, A Rechenmacher, R Quinn, TR Richards, GT Richmond, MW Rivetta, CH Rockosi, CM Ruthmansdorfer, K Sandford, D Schlegel, DJ Schneider, DP Sekiguchi, M Sergey, G Shimasaku, K Siegmund, WA Smee, S Smith, JA Snedden, S Stone, R Stoughton, C Strauss, MA Stubbs, C SubbaRao, M Szalay, AS Szapudi, I Szokoly, GP Thakar, AR Tremonti, C Tucker, DL Uomoto, A Berk, DV Vogeley, MS Waddell, P Wang, SI Watanabe, M Weinberg, DH Yanny, B Yasuda, N CA SDSS Collaboration TI The Sloan Digital Sky Survey: Technical summary SO ASTRONOMICAL JOURNAL LA English DT Article DE cosmology : observations; instrumentation : miscellaneous ID SURVEY COMMISSIONING DATA; SDSS FILTERS; GALAXIES; SYSTEM; STARS; PHOTOMETRY; DISCOVERY; EMISSION; QSOS AB The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed investigations of the distribution of luminous and nonluminous matter in the universe: a photometrically and astrometrically calibrated digital imaging survey of pi sr above about Galactic latitude 30 degrees in five broad optical bands to a depth of g' similar to 23 mag, and a spectroscopic survey of the approximately 10(6) brightest galaxies and 10(5) brightest quasars found in the photometric object catalog produced by the imaging survey. This paper summarizes the observational parameters and data products of the SDSS and serves as an introduction to extensive technical on-line documentation. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Chicago, Yerkes Observ, Williams Bay, WI 53191 USA. Apache Point Observ, Sunspot, NM 88349 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Eotvos Lorand Univ, Dept Phys Complex Syst, H-1117 Budapest, Hungary. Univ Tokyo, Dept Astron, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Sch Sci, Res Ctr Early Universe, Bunkyo Ku, Tokyo 1130033, Japan. Inst Adv Study, Princeton, NJ 08540 USA. Yale Univ, Dept Phys, New Haven, CT 06520 USA. Natl Astron Observ, Mitaka, Tokyo 1818588, Japan. Univ Tokyo, Inst Cosm Ray Res, Tanashi, Tokyo 1888502, Japan. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. USN Observ, Washington, DC 20392 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Tohoku Univ, Inst Astron, Aoba Ku, Sendai, Miyagi 9808578, Japan. Merrill Lynch Japan Inc, Tokyo 100, Japan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Royal Observ, Edinburgh EH9 3HJ, Midlothian, Scotland. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15232 USA. Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. Lucent Technol, Naperville, IL 60566 USA. Osserv Astron Trieste, Div Astron & Astrofis, I-34131 Trieste, Italy. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. RP York, DG (reprint author), Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA. RI Margon, Bruce/B-5913-2012; Stubbs, Christopher/C-2829-2012; Yasuda, Naoki/A-4355-2011; Csabai, Istvan/F-2455-2012; McKay, Timothy/C-1501-2009; OI Stubbs, Christopher/0000-0003-0347-1724; McKay, Timothy/0000-0001-9036-6150; Meiksin, Avery/0000-0002-5451-9057; Nonino, Mario/0000-0001-6342-9662; Csabai, Istvan/0000-0001-9232-9898 NR 45 TC 5252 Z9 5283 U1 11 U2 75 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2000 VL 120 IS 3 BP 1579 EP 1587 DI 10.1086/301513 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360LX UT WOS:000089670300033 ER PT J AU Pentericci, L Kurk, JD Rottgering, HJA Miley, GK van Breugel, W Carilli, CL Ford, H Heckman, T McCarthy, P Moorwood, A AF Pentericci, L Kurk, JD Rottgering, HJA Miley, GK van Breugel, W Carilli, CL Ford, H Heckman, T McCarthy, P Moorwood, A TI A search for clusters at high redshift II. A proto cluster around a radio galaxy at z=2.16 SO ASTRONOMY & ASTROPHYSICS LA English DT Letter DE galaxies : active; galaxies : clusters : general; galaxies : evolution; cosmology : observations; cosmology : early Universe; cosmology : large-scale structure of Universe AB VLT1 spectroscopic observations of Ly alpha-excess objects in the field of the clumpy radio galaxy 1138-262 at z = 2.16 have led to the discovery of 14 galaxies and one QSO at approximately the same distance as the radio galaxy. All galaxies have redshifts in the range 2.16+/-0.02, centered around the redshift of the radio galaxy, and are within a projected physical distance of 1.5 Mpc from it. The velocity distribution suggests that there are two galaxy subgroups having velocity dispersions of similar to 500 km s(-1) and similar to 300 km s(-1) and a relative velocity of 1800 km s(-1). If these are virialized structures, the estimated dynamical masses for the subgroups are similar to 9 and similar to 3 X 10(13) M-circle dot respectively, implying a total mass for the structure of more than 10(14) M-circle dot. The new observations, together with previous results, suggest that the structure of galaxies around 1138-262 is likely to be a forming cluster. C1 Max Planck Inst Astron, D-69117 Heidelberg, Germany. Sterrewacht Leiden, Leiden, Netherlands. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. European So Observ, D-85748 Garching, Germany. RP Pentericci, L (reprint author), Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany. EM laura@mpia-hd.mpg.de NR 19 TC 118 Z9 118 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2000 VL 361 IS 2 BP L25 EP L28 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365AJ UT WOS:000089926000002 ER PT J AU Revnivtsev, M Sunyaev, R Borozdin, K AF Revnivtsev, M Sunyaev, R Borozdin, K TI Discovery of a 0.08 Hz QPO in the power spectrum of black hole candidate XTE J1118+480 SO ASTRONOMY & ASTROPHYSICS LA English DT Letter DE stars : binaries : general; stars : flare; stars : neutron; stars : individual : XTE J1806-246; X-rays : stars ID QUASI-PERIODIC OSCILLATIONS; X-1 AB We found a strong QPO feature at 0.085 +/- 0.002 Hz in the power spectrum of an X-ray transient XTE J1118+480. The QPO was detected in PCA/RXTE data with an amplitude close to 10% rms, and width 0.034 +/- 0.006 Hz. The shape of the power spectrum is typical for black hole candidates: almost flat at frequencies lower than 0.03 Hz, roughly a power law with slope similar to 1.2 from 0.03 to 1 Hz, with steepening to similar to 1.6 at higher frequencies. The hard energy spectrum detected up to similar to 150 keV and the absence of significant X-ray variability at the high frequencies above 100 Hz strongly support the identification of XTE J1118+480 as black hole transient. C1 Russian Acad Sci, Space Res Inst, Moscow 117810, Russia. Max Planck Inst Astrophys, D-85740 Garching, Germany. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Revnivtsev, M (reprint author), Russian Acad Sci, Space Res Inst, Profsoyuznaya 84-32, Moscow 117810, Russia. EM revnivtsev@hea.iki.rssi.ru NR 24 TC 30 Z9 31 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2000 VL 361 IS 2 BP L37 EP L39 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365AJ UT WOS:000089926000005 ER PT J AU Tello, C Villela, T Smoot, GF Bersanelli, M Figueiredo, N De Amici, G Bensadoun, M Wuensche, CA Torres, S AF Tello, C Villela, T Smoot, GF Bersanelli, M Figueiredo, N De Amici, G Bensadoun, M Wuensche, CA Torres, S TI Spillover and diffraction sidelobe contamination in a double-shielded experiment for mapping Galactic synchrotron emission SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE methods : analytical; methods : observational; methods : laboratory; site testing; radio continuum : ISM ID DIFFERENTIAL MICROWAVE RADIOMETER; SKY MAPS; RADIATION; PREDICTIONS; FREQUENCIES; ANISOTROPY; SCALES; MODEL; GHZ AB We have analyzed observations from a radioastronomical experiment to survey the sky at decimetric wavelengths along with feed pattern measurements in order to account for the level of ground contamination entering the sidelobes. A major asset of the experiment is the use of a wire mesh fence around the rim-halo shielded antenna with the purpose of levelling out and reducing this source of stray radiation for zenith-centered 1-rpm circular scans. We investigate the shielding performance of the experiment by means of a geometric diffraction model in order to predict the level of the spillover and diffraction sidelobes in the direction of the ground. Using 408 MHz and 1465 feed measurements, the model shows how a weakly-diffracting and unshielded antenna configuration becomes strongly-diffracting and double-shielded as farfield diffraction effects give way to near-field ones. Due to the asymmetric response of the feeds, the orientation of their radiation fields with respect to the secondary must be known a priori before comparing model predictions with observational data. By adjusting the attenuation coefficient, of the wire mesh the model is able to reproduce the amount of differential ground pick-up observed during test measurements at 1465 MHz. C1 Inst Nacl Pesquisas Espaciais, Div Astrofis, BR-12201970 Sao Jose Dos Campos, Brazil. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Escola Fed Engn Itajuba, BR-37500000 Itajuba, Brazil. TRW R1 2128, Redondo Beach, CA 90278 USA. Newfield Wireless Inc, Berkeley, CA 94705 USA. Ctr Int Fis, Bogota, Colombia. RP Tello, C (reprint author), Inst Nacl Pesquisas Espaciais, Div Astrofis, CP 515, BR-12201970 Sao Jose Dos Campos, Brazil. RI Figueiredo, Newton/F-9976-2011 NR 36 TC 3 Z9 3 U1 0 U2 0 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 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD SEP PY 2000 VL 145 IS 3 BP 495 EP 508 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 352PW UT WOS:000089227900013 ER PT J AU Lin, DNC Murray, SD AF Lin, DNC Murray, SD TI On the two-phase structure of protogalactic clouds SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : formation; stars : formation ID COLD DARK-MATTER; TULLY-FISHER RELATION; GALAXY FORMATION; STAR-FORMATION; RING GALAXIES; FRAGMENTATION; SYSTEMS; STELLAR; SIMULATIONS; EVOLUTION AB In the gaseous envelope of protogalaxies, thermal instability leads to the formation of a population of cool fragments that are confined by the pressure of a residual hot background medium. In order to remain in a quasi-hydrostatic equilibrium, the residual gas evolves at approximately the virial temperature of the dark matter halo. Its density is determined by the requirements of thermal equilibrium. The hot gas is heated by compression and shock dissipation. The heating is balanced by direct energy loss due to bremsstrahlung emission and by conductive losses into the cool clouds, which are efficient radiators. The cool fragments are photoionized and heated by the extragalactic UV background and nearby massive stars. Several processes interact to determine the size distribution of the cool fragments. The smallest are evaporated due to conductive heat transfer from the hot gas. All fragments are subject to disruption due to hydrodynamic instabilities. The fragments also gain mass as a result of collisions and mergers and of condensation from the hot gas due to conduction. The size distribution of the fragments in turn determines the rate and efficiency of star formation during the early phase of galactic evolution. We have performed one-dimensional hydrodynamic simulations of the evolution of the hot and cool gas. The cool clouds are assumed to follow a power-law size distribution, and fall into the galactic potential, subject to drag from the hot gas. The relative amounts of the hot and cool gas are determined by the processes discussed above, and star formation occurs at a rate sufficient to maintain the cool clouds at 10(4) K. We present density distributions for the two phases and also for the stars for several cases, parameterized by the circular speeds of the potentials. Under some conditions, primarily low densities of the hot gas, conduction is more efficient than radiative processes at cooling the hot gas, limiting the X-ray radiation from the halo gas. C1 Univ Calif Santa Cruz, Lick Observ, UCO, Santa Cruz, CA 95064 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lin, DNC (reprint author), Univ Calif Santa Cruz, Lick Observ, UCO, Santa Cruz, CA 95064 USA. RI Murray, Stephen/I-8685-2016 OI Murray, Stephen/0000-0001-5597-090X NR 62 TC 20 Z9 20 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2000 VL 540 IS 1 BP 170 EP 183 DI 10.1086/309317 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356CW UT WOS:000089427600018 ER PT J AU Haney, LN AF Haney, LN TI FRamework Assessing Notorious Contributing Influences for Error (FRANCIE) SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT International Workshop on Human Factors in Space CY JUL 07-09, 1999 CL TOKYO, JAPAN SP Int Space Life Sci, Strateg Planning Working Grp, Natl Space Dev Agcy Japan DE human error; human reliability; human factors; human engineering; and human performance AB FRamework Assessing Notorious Contributing Influences for Error (FRANCIE) is a framework and methodology for the systematic analysis, characterization, and prediction of human error. It was developed in a NASA Advanced Concepts Project by Idaho National Engineering and Environmental Laboratory, NASA Ames Research Center, Boeing, and America West Airlines, with input from United Airlines and Idaho State University. It was hypothesized that development of a comprehensive taxonomy of error-type and contributing-influences, in a framework and methodology addressing issues important for error analysis, would result in a useful tool for human error analysis. The development method included capturing expertise of human factors and domain experts in the framework, and ensuring that the approach addressed issues important for future human error analysis. This development resulted in creation of a FRANCIE taxonomy for airline maintenance, and a FRANCIE framework and approach that addresses important issues: proactive and reactive, comprehensive error-type and contributing-influences taxonomy, meaningful error reduction strategies, multilevel analyses, multiple user types, compatible with existing methods, applied in design phase or throughout system life cycle, capture of lessons learned, and ease of application. FRANCIE was designed to apply to any domain, given taxonomy refinement. This is demonstrated by its application for an aviation operations scenario for a new precision landing aid. Representative error-types and contributing-influences, two example analyses, and a case study are presented. In conclusion, FRANCIE is useful for analysis of human error, and the taxonomy is a starting point for development of taxonomies allowing application to other domains, such as spacecraft maintenance, operations, medicine, process control, and other transportation industries. C1 Idaho State Univ, Pocatello, ID 83209 USA. RP Haney, LN (reprint author), Idaho Natl Lab, POB 1625, Idaho Falls, ID 83415 USA. EM lnh@inel.gov NR 7 TC 1 Z9 1 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD SEP PY 2000 VL 71 IS 9 SU S BP A145 EP A150 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 350VG UT WOS:000089121400029 PM 10993328 ER PT J AU MacLaren, DC Toyokuni, T Cherry, SR Barrio, JR Phelps, ME Herschman, HR Gambhir, SS AF MacLaren, DC Toyokuni, T Cherry, SR Barrio, JR Phelps, ME Herschman, HR Gambhir, SS TI PET imaging of transgene expression SO BIOLOGICAL PSYCHIATRY LA English DT Review DE transgene imaging; PET; gene expression; herpes simplex virus thymidine kinase; dopamine 2 receptor; reporter gene ID POSITRON-EMISSION-TOMOGRAPHY; THYMIDINE KINASE GENE; CONSERVED SERINE RESIDUES; GREEN FLUORESCENT PROTEIN; IN-VIVO; REPORTER GENE; LIVING ANIMALS; INTERNAL INITIATION; RETROVIRAL VECTORS; VIRAL-INFECTION AB A vital step in transgenic animal study and gene therapy is the ability to assay the extent of transgene expression. Unfortunately, classic methods of assaying transgene expression require biopsies or death of the subject. We are developing techniques to noninvasively and repetitively determine the location, duration, and magnitude of transgene expression in living animals. This will allow investigators and clinicians to assay the effectiveness of their particular experimental and therapeutic paradigms. Of radionuclide (single photon emission computed tomography, positron emission tomography [PET]) optical (green fluorescent protein, luciferase), and magnetic (magnetic resonance imaging) approaches, only the radionuclide approach has sufficient sensitivity and quantitation to measure the expression of genes in vivo. We describe the instrumentation involved in high resolution PET scanning. We also describe the principles of PET reporter gene/reporter probe in vivo imaging, the development of two in vivo reporter gene imaging systems, and the validation of our ability to noninvasively, quantitatively, and repetitively image gene expression in murine viral gene transfer and transgenic models. We compare the two reporter gene systems and discuss their utility for the study of transgenic animals and gene therapies. Finally, we mention alternative approaches to image gene expression by using radiolabeled antibody fragments to image specific proteins and radiolabeled oligonucleotides to image RNA messages directly. (C) 2000 Society of Biological Psychiatry. C1 Univ Calif Los Angeles, Dept Pharmacol, Sch Med, Crump Inst Biol Imaging, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Sch Med, US DOE, Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Sch Med, Dept Mol & Med Pharmacol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Sch Med, Inst Mol Biol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Sch Med, Jonsson Comprehens Canc Ctr, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Sch Med, Dept Biomath, Los Angeles, CA 90095 USA. RP MacLaren, DC (reprint author), Univ Calif Los Angeles, Dept Pharmacol, Sch Med, Crump Inst Biol Imaging, 611 Charles E Young Dr E,341 Boyer Hall, Los Angeles, CA 90095 USA. FU NCI NIH HHS [R01 CA84572-01, R01 CA82214-01] NR 78 TC 68 Z9 70 U1 1 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0006-3223 J9 BIOL PSYCHIAT JI Biol. Psychiatry PD SEP 1 PY 2000 VL 48 IS 5 BP 337 EP 348 DI 10.1016/S0006-3223(00)00970-7 PG 12 WC Neurosciences; Psychiatry SC Neurosciences & Neurology; Psychiatry GA 352RY UT WOS:000089232700001 PM 10978717 ER PT J AU Wu, HM Ratsep, M Young, CS Jankowiak, R Blankenship, RE Small, GJ AF Wu, HM Ratsep, M Young, CS Jankowiak, R Blankenship, RE Small, GJ TI High-pressure and stark hole-burning studies of chlorosome antennas from Chlorobium tepidum SO BIOPHYSICAL JOURNAL LA English DT Article ID GREEN PHOTOSYNTHETIC BACTERIA; RHODOPSEUDOMONAS-ACIDOPHILA STRAIN-10050; REACTION CENTER COMPLEXES; BCHL-C ANTENNAE; ENERGY-TRANSFER; BACTERIOCHLOROPHYLL-C; CHLOROFLEXUS-AURANTIACUS; SULFUR BACTERIA; RHODOBACTER-SPHAEROIDES; RESONANCE RAMAN AB Results from high-pressure and Stark hole-burning experiments on isolated chlorosomes from the green sulfur bacterium Chlorobium tepidum are presented, as well as Stark hole-burning data for bacteriochlorophyll c (BChl c) monomers in a poly(vinyl butyral) copolymer film. Large linear pressure shift rates of -0.44 and -0.54 cm(-1)/MPa were observed for the chlorosome BChl c Q(y)-band at 100 K and the lowest Q(y)-exciton level at 12 K, respectively. It is argued that approximately half of the latter shift rate is due to electron exchange coupling between BChl c molecules. The similarity between the above shift rates and those observed for the B875 and B850 BChl a rings of the light-harvesting complexes of purple bacteria is emphasized. For BChl c monomer, f Delta mu = 0.35 D, where Delta mu is the dipole moment change for the Q(y) transition and f is the local field correction factor. The data establish that Delta mu is dominated by the matrix-induced contribution. The change in polarizability (Delta alpha) for the Q(y) transition of the BChl c monomer is estimated at 19 Angstrom(3), which is essentially identical to that of the Chi a monomer. Interestingly, no Stark effects were observed for the lowest exciton level of the chlorosomes (maximum Stark field of 10(5) V/cm). Possible explanations for this are given, and these include consideration of structural models for the chlorosome BChl c aggregates. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USA. RP Small, GJ (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 91 TC 12 Z9 12 U1 0 U2 4 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD SEP PY 2000 VL 79 IS 3 BP 1561 EP 1572 PG 12 WC Biophysics SC Biophysics GA 349TD UT WOS:000089060900037 PM 10969017 ER PT J AU Savikhin, S Xu, W Chitnis, PR Struve, WS AF Savikhin, S Xu, W Chitnis, PR Struve, WS TI Ultrafast primary processes in PS I from Synechocystis so. PCC 6803: Roles of P700 and A(o) SO BIOPHYSICAL JOURNAL LA English DT Article ID PHOTOSYNTHETIC REACTION-CENTER; PICOSECOND FLUORESCENCE KINETICS; TIME-RESOLVED FLUORESCENCE; PRIMARY CHARGE SEPARATION; REACTION-CENTER COMPLEX; 2 REACTION CENTERS; PHOTOSYSTEM-I; ENERGY-TRANSFER; CORE ANTENNA; RHODOPSEUDOMONAS-VIRIDIS AB The excitation transport and trapping kinetics of core antenna-reaction center complexes from photosystem I of wild-type Synechocystis sp. PCC 6803 were investigated under annihilation-free conditions in complexes with open and closed reaction centers. For closed reaction centers, the long-component decay-associated spectrum (DAS) from global analysis of absorption difference spectra excited at 660 nm is essentially flat (maximum amplitude <10(-5) absorbance units). For open reaction centers, the long-time spectrum (which exhibits photobleaching maxima at similar to 680 and 700 nm, and an absorbance feature near 690 nm) resembles one previously attributed to (P700(+) - P700). For photosystem I complexes excited at 660 nm with open reaction centers, the equilibration between the bulk antenna and far-red chlorophylls absorbing at wavelengths >700 nm is well described by a single DAS component with lifetime 2.3 ps. For closed reaction centers, two DAS components (2.0 and 6.5 ps) are required to fit the kinetics. The overall trapping time at P700 (similar to 24 ps) is very nearly the same in either case. Our results support a scenario in which the time constant for the P700 --> A(0) electron transfer is 9-10 ps, whereas the kinetics of the subsequent A(0) --> A(1) electron transfer are still unknown. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Dept Biochem, Ames, IA 50011 USA. Iowa State Univ, Dept Biophys, Ames, IA 50011 USA. Iowa State Univ, Dept Mol Biol, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Struve, WS (reprint author), Iowa State Univ, Dept Chem, Gilman Hall, Ames, IA 50011 USA. NR 44 TC 46 Z9 52 U1 1 U2 4 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD SEP PY 2000 VL 79 IS 3 BP 1573 EP 1586 PG 14 WC Biophysics SC Biophysics GA 349TD UT WOS:000089060900038 PM 10969018 ER PT J AU Huang, Z Maness, PC Dowe, N Mohagheghi, A Newman, M McMillan, J AF Huang, Z Maness, PC Dowe, N Mohagheghi, A Newman, M McMillan, J TI Rapid detection of Zymomonas mobilis redox activity using 5-cyano-2,3-tolyl-tetra-zolium chloride (CTC) SO BIOTECHNIQUES LA English DT Article ID 5-CYANO-2,3-DITOLYL TETRAZOLIUM CHLORIDE; RESPIRING BACTERIA; CELL VIABILITY C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Huang, Z (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 USA SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD SEP PY 2000 VL 29 IS 3 BP 424 EP + PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 352DR UT WOS:000089199700004 PM 10997252 ER PT J AU Akhtari, M Bryant, HC Mamelak, AN Heller, L Shih, JJ Mandelkern, M Matlachov, A Ranken, DM Best, ED Sutherling, WW AF Akhtari, M Bryant, HC Mamelak, AN Heller, L Shih, JJ Mandelkern, M Matlachov, A Ranken, DM Best, ED Sutherling, WW TI Conductivities of three-layer human skull SO BRAIN TOPOGRAPHY LA English DT Article DE conductivity; skull; human; inhomogeneity; spongiosum; compact layer ID LANGUAGE-SPECIFIC CORTEX; REALISTIC HEAD MODELS; HUMAN AUDITORY-CORTEX; FINITE-ELEMENT MODEL; SOMATOSENSORY CORTEX; INTRACRANIAL LOCALIZATIONS; TONOTOPIC ORGANIZATION; IMPLANTED SOURCES; VOLUME-CONDUCTOR; INVERSE PROBLEM AB In this study, electrical conductivities of compact, spongiosum, and bulk layers of cadaver skull were determined at varying electric fields at room temperature. Current was applied and withdrawn over the top and bottom surfaces of each sample and potential drop across different layers was measured using the four-electrode method. We developed a model, which considers of variations in skull thicknesses, to determine the conductivity of the tri-layer skull and its individual anatomical structures. The results indicate that the spongiform and the two compact layers of the skull have significantly different and inhomogeneous conductivities ranging from 0.76 +/- .14 to 11.5 +/- 1.8 milliS/m. C1 Huntington Mem Hosp, Epilepsy & Brain Mapping Program, Pasadena, CA 91105 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Univ New Mexico, Sch Med, Dept Neurol, Albuquerque, NM 87131 USA. Univ New Mexico, Sch Med, Dept Neurosci, Albuquerque, NM 87131 USA. Univ Calif Irvine, Dept Phys, Irvine, CA 92717 USA. Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM USA. RP Akhtari, M (reprint author), Huntington Mem Hosp, Epilepsy & Brain Mapping Program, 10 Congress St,Suite 505, Pasadena, CA 91105 USA. FU NINDS NIH HHS [R01 NS20806] NR 74 TC 23 Z9 23 U1 0 U2 2 PU KLUWER ACADEMIC-HUMAN SCIENCES PRESS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0896-0267 J9 BRAIN TOPOGR JI Brain Topogr. PD FAL PY 2000 VL 13 IS 1 BP 29 EP 42 DI 10.1023/A:1007882102297 PG 14 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA 370BH UT WOS:000165101900004 PM 11073092 ER PT J AU Papamichael, K AF Papamichael, K TI Green building performance prediction/assessment SO BUILDING RESEARCH AND INFORMATION LA English DT Article DE cost; value; simulation; energy; environmental impact; green buildings; design tools; building performance AB To make decisions, building designers need to predict and assess the performance of their ideas with respect to various criteria, such as comfort, aesthetics, energy, environmental impact, economics, etc. Performance prediction with respect to environmental impact requires complicated models and massive computations, which are usually possible only through computer-based tools. This paper focuses on the use of computer-based tools for predicting and assessing building performance with respect to environmental impact criteria for the design of green buildings. It contains analyses of green performance prediction/assessment and descriptions of available tools, along with discussions on their use by different types of users. Finally, it includes analyses of the cost and benefits of green performance prediction and assessment. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Bldg Technol Dept, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Papamichael, K (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Bldg Technol Dept, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 19 TC 7 Z9 7 U1 0 U2 2 PU E & FN SPON PI LONDON PA 2-6 BOUNDARY ROW, LONDON SE1 8HN, ENGLAND SN 0961-3218 J9 BUILD RES INF JI Build. Res. Informat. PD SEP PY 2000 VL 28 IS 5-6 BP 394 EP 402 DI 10.1080/096132100418546 PG 9 WC Construction & Building Technology SC Construction & Building Technology GA 355AY UT WOS:000089364500010 ER PT J AU Dabberdt, WF Hales, J Zubrick, S Crook, A Krajewski, W Doran, JC Mueller, C King, C Keener, RN Bornstein, R Rodenhuis, D Kocin, P Rossetti, MA Sharrocks, F Stanley, EM AF Dabberdt, WF Hales, J Zubrick, S Crook, A Krajewski, W Doran, JC Mueller, C King, C Keener, RN Bornstein, R Rodenhuis, D Kocin, P Rossetti, MA Sharrocks, F Stanley, EM TI Forecast issues in the urban zone: Report of the 10th Prospectus Development Team of the US Weather Research Program SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID HEAT-STORAGE; MODEL; SNOW AB The 10th Prospectus Development Team (PDT-IO) of the U.S. Weather Research Program was charged with identifying research needs and opportunities related to the short-term prediction of weather and air quality in urban forecast zones. Weather has special and significant impacts on large numbers of the U.S. population who live in major urban areas. It is recognized that urban users have different weather information needs than do their rural counterparts. Further, large urban areas can impact local weather and hydrologic;ic processes in various ways. The recommendations of the team emphasize that human life and well-being in urban areas can be protected and enjoyed to a significantly greater degree. In particular, PDT-IO supports the need for 1) improved access to real-time weather information, 2) improved tailoring of weather data to the specific needs of individual user groups, and 3) more user-specific forecasts of weather and air quality. Specific recommendations fall within nine thematic areas: 1) development of a user-oriented weather database; 2) focused research on the impacts of visibility and icing on transportation; 3) improved understanding and forecasting of winter storms; 4) improved understanding and Forecasting of convective storms; 5) improved forecasting of intense/severe lightning; 6) further research into the impacts of large urban areas on the location and intensity of urban convection; 7) focused research on the application of mesoscale forecasting in support of emergency response and air quality; 8) quantification and reduction of uncertainty in hydrological, meteorological, and air quality modeling; and 9) the need for improved observing systems. An overarching recommendation of PDT-10 is that research into understanding and predicting weather impacts in urban areas should receive increased emphasis by the atmospheric science community at large, and that urban weather should be a focal point of the U.S. Weather Research Program. C1 Natl Ctr Atmospher Res, Off Director, Boulder, CO 80307 USA. Envair, Pasco, WA USA. Natl Weather Serv, Natl Ocean & Atmospher Adm, Sterling, VA USA. Univ Iowa, Iowa Inst Hydraul Res, Iowa City, IA 52242 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Natl Ocean & Atmospher Adm, Environm Techniques Lab, Boulder, CO USA. Duke Energy, Charlotte, NC USA. San Jose State Univ, San Jose, CA 95192 USA. Natl Weather Serv, Kansas City, MO USA. Weather Channel, Atlanta, GA USA. US Dept Transportat, Cambridge, MA USA. Fed Emergency Management Assoc, Washington, DC USA. RP Dabberdt, WF (reprint author), Natl Ctr Atmospher Res, Off Director, POB 3000, Boulder, CO 80307 USA. NR 37 TC 32 Z9 33 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 2000 VL 81 IS 9 BP 2047 EP 2064 DI 10.1175/1520-0477(2000)081<2047:FIITUZ>2.3.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348EG UT WOS:000088972100002 ER PT J AU Rzyman, K Moser, Z Miodownik, AP Kaufman, L Watson, RE Weinert, M AF Rzyman, K Moser, Z Miodownik, AP Kaufman, L Watson, RE Weinert, M TI Enthalpies of formation of AlFe: Experiment versus theory SO CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY LA English DT Article ID IRON ALLOYS AB Enthalpies of formation for AlFe were determined by solution calorimetry over a wide concentration range (X-AI=0.40-0.50) and over a wide temperature interval (T = 296 to 1029 K). The value of enthalpy of formation becomes more negative with deviations from the stoichiometric composition. The temperature dependence of the experimental enthalpy exhibits an unusual maximum of its value at intermediate temperatures. These results will be discussed in relation to ab initio calculations, with particular attention to the spin polarisation energy of elemental Fe and the influence of the magnetic properties of Fe on the correct choice of reference state for paramagnetic AlFe. C1 Polish Acad Sci, Inst Met & Mat Sci, PL-3059 Krakow, Poland. Univ Surrey, Sch Mech & Mat Engn, Dept Mat Sci & Engn, Guildford GU2 5XH, Surrey, England. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Rzyman, K (reprint author), Polish Acad Sci, Inst Met & Mat Sci, 25 Reymonta St, PL-3059 Krakow, Poland. RI MOSER, Zbigniew/A-6228-2008 NR 28 TC 16 Z9 17 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0364-5916 J9 CALPHAD JI Calphad-Comput. Coupling Ph. Diagrams Thermochem. PD SEP PY 2000 VL 24 IS 3 BP 309 EP 318 DI 10.1016/S0364-5916(01)00007-4 PG 10 WC Thermodynamics; Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Thermodynamics; Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 420GV UT WOS:000167998000005 ER PT J AU Keating, GA Sinha, R Layton, D Salmon, CP Knize, MG Bogen, KT Lynch, CF Alavanja, M AF Keating, GA Sinha, R Layton, D Salmon, CP Knize, MG Bogen, KT Lynch, CF Alavanja, M TI Comparison of heterocyclic amine levels in home-cooked meats with exposure indicators (United States) SO CANCER CAUSES & CONTROL LA English DT Article DE cooked meat; doneness; exposure; heterocyclic amines ID WELL-DONE; COLORECTAL ADENOMAS; VARYING DEGREES; BREAST-CANCER; RED MEAT; RISK; PRODUCTS; CONSUMPTION; TEMPERATURE; COLON AB Objective: To compare indicators of heterocyclic amine (HCA) exposure with HCA concentrations in home-cooked meat samples. Methods: Pan-fried hamburger and steak samples were obtained from individuals stating a preference for medium, well done and very well done meat. Concentrations of DiMeIQx, IFP, MeIQx and PhIP were determined by HPLC. Results: HCA concentrations at the three doneness levels were not significantly different using the participants' self-reported doneness preference to categorize samples. Using doneness levels determined at the time the meat was cooked and photograph analysis to categorize samples, HCA concentrations increased with doneness level and significant differences were observed between the very well done and lower doneness levels. When assigned to doneness levels by photograph analysis, mean concentrations (ng/g cooked meat) of DiMeIQx, IFP, MeIQx, and PhIP were 0.18, 0.16, 0.65 and 0.47 in well done hamburger and 0.61, 0.74, 1.88 and 2.04 in very well done hamburger. In steak, mean concentrations were 0.24, 0.10, 0.79 and 0.59 in well done steak and 0.45, 0.14, 1.87 and 0.62 in very well done steak. Conclusions: HCA levels in home-cooked meat samples were significantly different when samples were visually classified for doneness, but not when self-reported doneness preference was used to classify doneness. C1 Univ Calif Lawrence Livermore Natl Lab, Hlth & Ecol Assessment Div, Livermore, CA 94551 USA. NCI, Environm Epidemiol Branch, Bethesda, MD 20892 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. Univ Iowa, Dept Prevent Med & Environm Hlth, Iowa City, IA 52242 USA. NCI, Epidemiol & Biostat Program, Bethesda, MD 20892 USA. RP Keating, GA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Hlth & Ecol Assessment Div, Box 808,L-396, Livermore, CA 94551 USA. RI Sinha, Rashmi/G-7446-2015 OI Sinha, Rashmi/0000-0002-2466-7462 FU NCI NIH HHS [CA55861] NR 19 TC 33 Z9 33 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0957-5243 J9 CANCER CAUSE CONTROL JI Cancer Causes Control PD SEP PY 2000 VL 11 IS 8 BP 731 EP 739 DI 10.1023/A:1008935407971 PG 9 WC Oncology; Public, Environmental & Occupational Health SC Oncology; Public, Environmental & Occupational Health GA 355XC UT WOS:000089413000008 PM 11065010 ER PT J AU Guliaev, AB Sagi, J Singer, B AF Guliaev, AB Sagi, J Singer, B TI Sequence-dependent conformational perturbation in DNA duplexes containing an epsilon A center dot T mismatch using molecular dynamics simulation SO CARCINOGENESIS LA English DT Article ID PARTICLE MESH EWALD; IRREGULAR NUCLEIC-ACIDS; STRUCTURAL CHARACTERIZATION; ENERGY MINIMIZATION; THYMINE DIMER; MAJOR ADDUCT; NMR; REPAIR; SPECIFICITY; SYSTEMS AB Previous experiments from this laboratory showed that 1,N(6)-ethenoadenine (epsilon A) in 15mer DNA oligonucleotide duplexes with GG epsilon AGG and CC epsilon ACC central sequences is repaired 3-5-fold more efficiently than in duplexes containing AA epsilon AAA and TT epsilon ATT central sequences. This sequence dependence in repair rates appeared to correlate with the observed thermodynamic stability of these duplexes [Hang et al, (1998) J, Biol, Chem,, 273, 33406-33413], In the present work, unrestrained molecular dynamics was used to evaluate the sequence-dependent structural features of these duplexes. Explicit solvent and the particle mesh Ewald method were applied for the accurate representation of the electrostatic interactions. The differences observed in the axis- and intra-base pair parameters were primarily localized at the epsilon A.T mismatch in all sequences and indicate conformational diversity between the structures. However, all four structures remained in the B-conformational family, In the tip, tilt and propeller twist parameters for the five central base pairs, larger perturbations were found for the two duplexes with epsilon A flanked by A or T bases than for duplexes with epsilon A flanked by G or C bases. As a result of these perturbations, the average global curvature of the AA epsilon AAA and TT epsilon ATT DNA duplexes was larger by similar to 12 degrees than that of the duplexes with the GG epsilon AGG and CC epsilon ACC central sequences. The observed conformational differences between the duplexes containing A or T and G or C neighbors of epsilon A may contribute to the observed differential enzymatic repair of the same sequences. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Div Life Sci, Berkeley, CA 94720 USA. Hungarian Acad Sci, Inst Chem, Chem Res Ctr, H-1525 Budapest, Hungary. RP Singer, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Div Life Sci, Berkeley, CA 94720 USA. EM abguliaev@lbl.gov FU NCI NIH HHS [CA47723, CA72079] NR 47 TC 12 Z9 13 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD SEP PY 2000 VL 21 IS 9 BP 1727 EP 1736 DI 10.1093/carcin/21.9.1727 PG 10 WC Oncology SC Oncology GA 352FU UT WOS:000089204500013 PM 10964105 ER PT J AU Cunningham, J Oiwa, Y Nagy, D Podsakoff, G Colosi, P Bankiewicz, KS AF Cunningham, J Oiwa, Y Nagy, D Podsakoff, G Colosi, P Bankiewicz, KS TI Distribution of AAV-TK following intracranial convection-enhanced delivery into rats SO CELL TRANSPLANTATION LA English DT Article; Proceedings Paper CT 6th Annual Meeting of the American-Society-for-Neural-Transplantation-and-Repair (ASNTR) CY APR, 1999 CL CLEARWATER, FLORIDA SP Amer Soc Neural Transplantat & Repair DE adeno-associated virus; thymidine kinase (ACC-TK); intracranial delivery; convection-enhanced delivery ID ADENOASSOCIATED VIRUS VECTORS; GENE-EXPRESSION; IN-VIVO; VIRAL-ANTIGENS; BRAIN; TRANSDUCTION; INFUSION; THERAPY; NEURONS; VOLUME AB Adeno-associated virus (AAV)-based vectors are being tested in animal models as viable treatments for glioma and neurodegenerative disease and could potentially be employed to target a variety of central nervous system disorders. The relationship between dose of injected vector and its resulting distribution in brain tissue has not been previously reported nor has the most efficient method of delivery been determined. Hen we report that convection-enhanced delivery (CED) of 2.5 x 10(8), 2.5 x 10(9), or 2.5 x 10(10) particles of AAV-thymidine kinase (AAV-TK) into rat brain revealed a clear dose response. In the high-dose group, a volume of 300 mm(3) of brain tissue was partially transduced. Results showed that infusion pump and subcutaneous osmotic pumps were both capable of delivering vector via CED and that total particle number was the most important determining factor in obtaining efficient expression. Results further showed differences in histopathology between the delivery groups. While administration of vector using. infusion pump had relatively benign effects, the use of osmotic pumps resulted in notable toxicity to the surrounding brain tissue. To determine tissue distribution of vector following intracranial delivery, PCR analysis was performed on tissues from rats that received high doses of AAV-TK. three weeks following CED, vector could be detected in both hemispheres of the brain, spinal cord, spleen, and kidney. C1 NINDS, Mol Therapeut Sect, LMMN, NIH, Bethesda, MD 20892 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. RP Bankiewicz, KS (reprint author), NINDS, Mol Therapeut Sect, LMMN, NIH, 36 Convent Dr,Bldg 36,Room 5W21,MSC 4164, Bethesda, MD 20892 USA. NR 28 TC 58 Z9 61 U1 0 U2 3 PU COGNIZANT COMMUNICATION CORP PI ELMSFORD PA 3 HARTSDALE ROAD, ELMSFORD, NY 10523-3701 USA SN 0963-6897 J9 CELL TRANSPLANT JI Cell Transplant. PD SEP-OCT PY 2000 VL 9 IS 5 BP 585 EP 594 PG 10 WC Cell & Tissue Engineering; Medicine, Research & Experimental; Transplantation SC Cell Biology; Research & Experimental Medicine; Transplantation GA 380LE UT WOS:000165702700004 PM 11144956 ER PT J AU Bankiewicz, KS Bringas, J Pivirotto, P Kutzscher, E Nagy, D Emborg, ME AF Bankiewicz, KS Bringas, J Pivirotto, P Kutzscher, E Nagy, D Emborg, ME TI Technique for bilateral intracranial implantation of cells in monkeys using an automated delivery system SO CELL TRANSPLANTATION LA English DT Article; Proceedings Paper CT 6th Annual Meeting of the American-Society-for-Neural-Transplantation-and-Repair (ASNTR) CY APR, 1999 CL CLEARWATER, FLORIDA SP Amer Soc Neural Transplantat & Repair DE cell therapy; primates; crafting; CNS; magnetic resonance imaging ID NERVE GROWTH-FACTOR; PRIMATE BRAIN; NEURAL TRANSPLANTATION; MAGNETIC-RESONANCE; GENE-TRANSFER; RAT-BRAIN; GRAFTS; FIBROBLASTS; STEREOTAXIS; TOMOGRAPHY AB Intracerebral grafting combined with gene transfer may provide a powerful technique for local delivery of therapeutic agents into the CNS. The present study was undertaken to: (i) develop a reliable and reproducible automated cell implantation system, (ii) determine optimal implantation parameters of cells into the striatum, (iii) determine upper safe limits of cellular implantation into the neostriatum of monkeys. Autologous fibroblasts were infused into six sites of the striatum in nonhuman primates (Macaca mulatta, n = 11). Twenty-six-gauge cannulae were inserted vertically through cortical entry sites into the striatum (two sites in the caudate nucleus and four sites in the putamen) at predefined coordinates based on magnetic resonance imaging (MRI). The cannulae were guided by an electronically operated, hydraulic micropositioner and withdrawn at controlled rates, while cells (5, 10, 20, 40, or 80 mul/site) were infused simultaneously. Varying infusion rates and cell concentrations were also evaluated. Visualization and evaluation of graft placement were performed using contrast MRI at 3-5 days postsurgery. Animals were monitored for signs of clinical complications and sacrificed 2 weeks following surgery. Postimplantation MRI revealed a tissue mass effect of the implant with shifting of midline, edema, and infiltration of the white tracts at 40 and 80 mul/site. In addition, these animals developed transient hemiparesis contralateral to the implant site. MRI of animals grafted with 20 mul/site exhibited columnar-shaped implants and evidence of infiltration into white matter tracts possibly due to a volume effect. No clinical side effects were seen in this group. At 14 days post surgery, MRI scans showed consistent columnar grafts (measuring approximately 5 mm in height) throughout the striatum in animals implanted with 5 or 10 mul/site. No signs of clinical side effects were associated with these volumes and postmortem histological examination confirmed MRI observations. Optimal surgical parameters for delivery of cells into the striatum consist of a graft volume of 10 mul/site, an infusion rate of 1.6 mul/min, a cell concentration of 2.0 x 10(5) cells/mul. and a cannula withdrawal rate of 0.75 mm/min. These results show that infusion of cells into the striatum can be done in a safe and routine manner. C1 NINDS, Mol Therapeut Sect, LMMN, NIH, Bethesda, MD 20892 USA. Cromedica Inc, Victoria, BC, Canada. Pacific Neurosci Inst, Orinda, CA USA. UC Berkeley, LBNL, Ctr Funct Imaging, Berkeley, CA USA. Rush Presbyterian St Lukes Med Ctr, Res Ctr Brain Repair, Chicago, IL 60612 USA. RP Bankiewicz, KS (reprint author), NINDS, Mol Therapeut Sect, LMMN, NIH, 36 Convent Dr,Bldg 36,Rm 5W21,MSC 4164, Bethesda, MD 20892 USA. NR 28 TC 12 Z9 12 U1 0 U2 0 PU COGNIZANT COMMUNICATION CORP PI ELMSFORD PA 3 HARTSDALE ROAD, ELMSFORD, NY 10523-3701 USA SN 0963-6897 J9 CELL TRANSPLANT JI Cell Transplant. PD SEP-OCT PY 2000 VL 9 IS 5 BP 595 EP 607 PG 13 WC Cell & Tissue Engineering; Medicine, Research & Experimental; Transplantation SC Cell Biology; Research & Experimental Medicine; Transplantation GA 380LE UT WOS:000165702700005 PM 11144957 ER PT J AU Miller, LM Tibrewala, J Carlson, CS AF Miller, LM Tibrewala, J Carlson, CS TI Examination of bone chemical composition in osteoporosis using fluorescence-assisted synchrotron infrared microspectroscopy SO CELLULAR AND MOLECULAR BIOLOGY LA English DT Article DE infrared (IR) spectroscopy; infrared (IR) microspectroscopy; fluorescence microscopy; synchrotron; bone; osteoporosis ID CALCIUM-PHOSPHATE; EARLY DEPOSITS; SOLID-PHASE; PO4 DOMAIN; SPECTROSCOPY; COLLAGEN; DISEASE; AGE; OSTEOARTHRITIS; PERFORMANCE AB Although it is clear that osteoporosis is associated with a reduction in bone mass and a fragile skeleton, it is not understood whether the chemical composition of osteoporotic bone is different from normal bone. In this study, cynomolgus monkeys (Macaca fascicularis) were administered fluorochrome labels at one and two years after ovariectomy (Ovx) or Sham ovariectomy (intact), that were taken up into newly remodeled bone. Using fluorescence-assisted synchrotron infrared microspectroscopy, the chemical composition of bone from intact versus Ovx monkeys has been compared. Results from overall composition distributions (labeled + non-labeled bone) reveal similar carbonate / protein and phosphate / protein ratios, but increased acid phosphate content and different collagen structure in the Ovx animals. Analysis of the fluorochrome-labeled bone indicates similar degrees of mineralization in bone remodeled after one year, but decreased mineralization in Ovx bone remodeled two years after surgery. Thus, bone from monkeys with osteoporosis can be characterized as having abnormal collagen structure and reduced rates of mineralization. Coupled with factors such as trabecular architecture and bone shape and size, these ultrastructural factors may play a contributing role in the increased bone fragility in osteoporosis. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Univ Minnesota, Coll Vet Med, Dept Vet Diagnost Med, St Paul, MN 55108 USA. RP Miller, LM (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source, Bldg 725 D, Upton, NY 11973 USA. FU NCRR NIH HHS [RR-14099] NR 26 TC 25 Z9 25 U1 0 U2 2 PU CELLULAR & MOLECULAR BIOLOGY PI NOISY-LE-GRAND PA PROF R WEGMANN RESIDENCE HAUSSMANN 1 AVENUE DU PAVE NEUF, 93160 NOISY-LE-GRAND, FRANCE SN 0145-5680 J9 CELL MOL BIOL JI Cell. Mol. Biol. PD SEP PY 2000 VL 46 IS 6 BP 1035 EP 1044 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 348JC UT WOS:000088980900003 PM 10976861 ER PT J AU Takeda, T Momose, A Yu, QW Yuasa, T Dilmanian, FA Akatsuka, T Itai, Y AF Takeda, T Momose, A Yu, QW Yuasa, T Dilmanian, FA Akatsuka, T Itai, Y TI New types of X-ray computed tomography (CT) with synchrotron radiation: Fluorescent X-ray CT and phase-contrast X-ray CT using interferometer SO CELLULAR AND MOLECULAR BIOLOGY LA English DT Article DE monochromatic X-ray computed tomography; synchrotron radiation; fluorescent X-ray CT; phase-contrast X-ray CT; thyroid imaging; contrast imaging; tracer element imaging; tumor imaging; soft tissue imaging ID MICROTOMOGRAPHY; ENERGY; RESOLUTION; OPERATION; SPECIMEN; SYSTEM; IMAGE; BONE AB New types of X-ray computed tomography (CT), fluorescent X-ray CT and phase-contrast X-ray CT are being developed for biomedical research. While fluorescent scanning X-ray CT (FXCT) can detect specific contrast elements, or endogenous iodine, at very low content (less than 400 pg iodine of tissue in a volume of 8 x 10(-6) ml), the phase-contrast X-ray CT (PCCT) is a highly sensitive imaging technique to differentiate between different biological tissue types (based on their specific gravity variation) without the use of a contrast agent. Therefore, we can expect functional diagnosis with FXCT, and high contrast, high resolution biological imaging with PCCT. In this paper, a human thyroid gland imaged by FXCT, and a metastatic human cancerous lesion depicted using PCCT are presented. The latter method used a newly manufactured, large, monolithic, X-ray interferometer, which is described in this paper in detail. C1 Univ Tsukuba, Inst Clin Med, Tsukuba, Ibaraki 3058575, Japan. Hitachi Ltd, Adv Res Lab, Hatoyama, Saitama 3500395, Japan. Yamagata Univ, Fac Engn, Yonezawa, Yamagata 9928510, Japan. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Takeda, T (reprint author), Univ Tsukuba, Inst Clin Med, Tsukuba, Ibaraki 3058575, Japan. RI Yuasa, Tetsuya/F-5006-2013 NR 52 TC 32 Z9 34 U1 0 U2 6 PU CELLULAR & MOLECULAR BIOLOGY PI NOISY-LE-GRAND PA PROF R WEGMANN RESIDENCE HAUSSMANN 1 AVENUE DU PAVE NEUF, 93160 NOISY-LE-GRAND, FRANCE SN 0145-5680 J9 CELL MOL BIOL JI Cell. Mol. Biol. PD SEP PY 2000 VL 46 IS 6 BP 1077 EP 1088 PG 12 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 348JC UT WOS:000088980900007 PM 10976865 ER PT J AU Berman, GP Demikhovskii, VY Kamenev, DI AF Berman, GP Demikhovskii, VY Kamenev, DI TI Symmetry of quantum phase space in a degenerate Hamiltonian system SO CHAOS LA English DT Article ID CYCLOTRON-RESONANCE; EVOLUTION; CHAOS; MAP AB The structure of the global "quantum phase space" is analyzed for the harmonic oscillator perturbed by a monochromatic wave in the limit when the perturbation amplitude is small. Usually, the phenomenon of quantum resonance was studied in nondegenerate [G. M. Zaslavsky, Chaos in Dynamic Systems (Harwood Academic, Chur, 1985)] and degenerate [Demikhovskii, Kamenev, and Luna-Acosta, Phys. Rev. E 52, 3351 (1995)] classically chaotic systems only in the particular regions of the classical phase space, such as the center of the resonance or near the separatrix. The system under consideration is degenerate, and even an infinitely small perturbation generates in the classical phase space an infinite number of the resonant cells which are arranged in the pattern with the axial symmetry of the order 2 mu (where mu is the resonance number). We show analytically that the Husimi functions of all Floquet states (the quantum phase space) have the same symmetry as the classical phase space. This correspondence is demonstrated numerically for the Husimi functions of the Floquet states corresponding to the motion near the elliptic stable points (centers of the classical resonance cells). The derived results are valid in the resonance approximation when the perturbation amplitude is small enough, and the stochastic layers in the classical phase space are exponentially thin. The developed approach can be used for studying a global symmetry of more complicated quantum systems with chaotic behavior. (C) 2000 American Institute of Physics. [S1054-1500(00)00802-8]. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Nizhnii Novgorod State Univ, Nizhnii Novgorod 603600, Russia. Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. RP Berman, GP (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM gpb@lanl.gov NR 15 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1054-1500 EI 1089-7682 J9 CHAOS JI Chaos PD SEP PY 2000 VL 10 IS 3 BP 670 EP 675 AR PII [S1054-1500(00)00802-8] DI 10.1063/1.1285965 PG 6 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 352BK UT WOS:000089194500018 ER PT J AU Scheihing, P AF Scheihing, P TI A boost for energy-related research SO CHEMICAL ENGINEERING LA English DT Letter C1 US DOE, Off Ind Technol, Washington, DC USA. RP Scheihing, P (reprint author), US DOE, Off Ind Technol, Washington, DC USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CHEMICAL WEEK ASSOCIATES PI NEW YORK PA 888 SEVENTH AVE, 26TH FL, NEW YORK, NY 10106 USA SN 0009-2460 J9 CHEM ENG-NEW YORK JI Chem. Eng. PD SEP PY 2000 VL 107 IS 10 BP 8 EP 8 PG 1 WC Engineering, Chemical SC Engineering GA 359LE UT WOS:000089611700003 ER PT J AU Tsouris, C Dong, JH AF Tsouris, C Dong, JH TI Effects of electric fields on phase inversion of liquid-liquid dispersions SO CHEMICAL ENGINEERING SCIENCE LA English DT Article C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Tsouris, C (reprint author), Oak Ridge Natl Lab, Div Chem Technol, POB 2008, Oak Ridge, TN 37831 USA. RI Tsouris, Costas/C-2544-2016 OI Tsouris, Costas/0000-0002-0522-1027 NR 11 TC 6 Z9 6 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD SEP PY 2000 VL 55 IS 17 BP 3571 EP 3574 DI 10.1016/S0009-2509(99)00571-0 PG 4 WC Engineering, Chemical SC Engineering GA 319PW UT WOS:000087351200022 ER PT J AU Soong, Y Fauth, DJ Knoer, JP AF Soong, Y Fauth, DJ Knoer, JP TI Ultrasonic characterizations of solids holdup in a bubble column reactor SO CHEMICAL ENGINEERING & TECHNOLOGY LA English DT Article ID 3-PHASE FLUIDIZED-BED AB For the optimum design and operation of gas-liquid-solid three-phase reactors, the degree of dispersion of the solid (catalyst) in the re actor must be measured, understood, and controlled. Accurate means of diagnosing the solids holdup are needed. An ultrasonic transmission technique has been developed to measure this parameter in a gas-liquid-solid bubble column reactor. The results presented in this study show that the transit time of an ultrasonic signal is influenced by the variation of solids holdup and the operating conditions in the bubble column. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Soong, Y (reprint author), US DOE, Natl Energy Technol Lab, POB 10940, Pittsburgh, PA 15236 USA. NR 13 TC 1 Z9 1 U1 2 U2 3 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0930-7516 J9 CHEM ENG TECHNOL JI Chem. Eng. Technol. PD SEP PY 2000 VL 23 IS 9 BP 751 EP + DI 10.1002/1521-4125(200009)23:9<751::AID-CEAT751>3.0.CO;2-L PG 8 WC Engineering, Chemical SC Engineering GA 353XT UT WOS:000089301300002 ER PT J AU Dong, HL Fredrickson, JK Kennedy, DW Zachara, JM Kukkadapu, RK Onstott, TC AF Dong, HL Fredrickson, JK Kennedy, DW Zachara, JM Kukkadapu, RK Onstott, TC TI Mineral transformation associated with the microbial reduction of magnetite SO CHEMICAL GEOLOGY LA English DT Article; Proceedings Paper CT Annual Meeting of the Geological-Society-of-America CY OCT 26-29, 1998 CL TORONTO, CANADA SP Geol Soc Amer DE Shewanella putrefaciens; reduction; magnetite; siderite; vivianite ID ULTRAFINE-GRAINED MAGNETITE; ANAEROBIC LAKE-SEDIMENTS; IRON-REDUCING BACTERIUM; DISSIMILATORY REDUCTION; MOSSBAUER-SPECTROSCOPY; FE(III) REDUCTION; HUMIC SUBSTANCES; EARLY DIAGENESIS; METAL REDUCTION; FERRIC IRON AB Although dissimilatory iron reducing bacteria (DIRB) are capable of reducing a number of metals in oxides and soluble forms, the factors controlling the rate/extent of magnetite reduction and the nature of the mineral products resulting from magnetite reduction are not well understood. This study was carried out to investigate mechanisms and biogeochemical processes occurring during magnetite reduction by the DIRE, Shewanella putrefaciens strains CN32 and MR-1. Reduction experiments were pel formed with biogenic and synthetic magnetite in well-defined solutions. Biogenic magnetite was generated via microbial reduction of hydrous ferric oxide (HFO). Biogenic magnetite in solutions buffered with either bicarbonate (HCO3-) or 1,4-piperazinedierhanesulfonic (PIPES), with or without P, was inoculated with strain CN32 and provided with lactate as the electron donor. Synthetic magnetite in a bacteriological growth medium (M1) was inoculated with either aerobically or anaerobically grown cells of strain (CN32 or MR-1). Fe(II) production was determined by HCl extraction of bioreduced samples in comparison to uninoculated controls, and the resulting solids were characterized by X-ray diffraction (XRD), Mossbauer spectroscopy, scanning and transmission electron microscopy (SEM and TEM). The extent and rate of biogenic magnetite reduction in the bicarbonate-buffered medium was higher than that in the PIPES-buffered medium, via complexation of bioproduced Fe(II) with HCO3- (or PO43-) and formation of siderite (vivianite). S, putrefaciens CN32 reduced more synthetic than biogenic magnetite with differences attributed mainly to medium composition. In the HCO3--buffered solutions, Fe(III) in the biogenic magnetite was reduced to Fe(II), and siderite precipitated. In the PIPES-buffered medium, Fe(III) in biogenic magnetite was also reduced to Fe(II), but no secondary mineral phases were observed. Vivianite formed in those solutions containing P and in all synthetic magnetite treatments where there was sufficient supply of P from the M1 medium. Electron microscopy and Mossbauer spectroscopy results suggest that the reduction process involves dissolution-precipitation mechanisms as opposed to solid state conversion of magnetite to vivianite or siderite, The aqueous medium, pH, strain type, and bacterial growth conditions all affected the extent of magnetite reduction. The ability of DIRE to utilize Fe(III) in crystalline magnetite as an electron acceptor could have significant implications for biogeochemical processes in sediments where Fe(III) in magnetite represents the largest pool of electron acceptor. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Dong, HL (reprint author), Princeton Univ, Dept Geosci, Guyot Hall, Princeton, NJ 08544 USA. OI Kennedy, David/0000-0003-0763-501X NR 53 TC 102 Z9 106 U1 6 U2 49 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD SEP 1 PY 2000 VL 169 IS 3-4 BP 299 EP 318 DI 10.1016/S0009-2541(00)00210-2 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 349HN UT WOS:000089039800005 ER PT J AU Tobin, KJ Colwell, FS Onstott, TC Smith, R AF Tobin, KJ Colwell, FS Onstott, TC Smith, R TI Recent calcite spar in an aquifer waste plume: a possible example of contamination driven calcite precipitation SO CHEMICAL GEOLOGY LA English DT Article; Proceedings Paper CT Annual Meeting of the Geological-Society-of-America CY OCT 26-29, 1998 CL TORONTO, CANADA SP Geol Soc Amer DE calcite; Test Area North; precipitation aquifer ID COASTAL-PLAIN SEDIMENTS; SULFATE REDUCTION; DIAGENESIS; GROUNDWATER; TEMPERATURE; CEMENTATION; MANGANESE; CHEMISTRY; ARAGONITE; RATES AB This paper documents possible modern (within the last 50 years) calcite cementation within an unconfined contaminated aquifer at the Test: Area North (TAN) on the Idaho National Engineering and Environmental Laboratory site. Inferred modern calcite occurs at the distal tips of the latest generation of calcite cement and has bright luminescence when examined by cathodoluminescence. Luminescent distal tips have elevated Mn values (up to 6400 ppm) when compared with other TAN calcite cement (<200 ppm). Additionally, speciation modeling with PHREEQE indicates that modern TAN groundwater exhibits a slight supersaturation with respect to calcite (calculated saturation indexes range from 0.2 to 0.5). The observed abundance of luminescent distal tips (< 1-38 mu g calcite/g total sample) is significantly less than the potential calcite precipitation (250-1100 mu g calcite/g total sample) indicated by laboratory microbial activity measurements; a finding consistent with previous studies. Finally, while our results do not elucidate the specific mechanism(s) responsible for the elevated Mn present in some TAN calcite, we do demonstrate at least an indirect microbial involvement for Mn enrichment, Therefore, it is conceivable that geochemical signatures indicative of distinctive redox conditions can be recognized in recently formed calcite from other contaminated groundwater systems. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. Idaho Natl Lab, Dept Biotechnol, Idaho Falls, ID 83415 USA. RP Tobin, KJ (reprint author), Univ Illinois, Dept Earth & Environm Sci, M-C 186,845 W Taylor St, Chicago, IL 60607 USA. EM kjtobin@uic.edu NR 42 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD SEP 1 PY 2000 VL 169 IS 3-4 BP 449 EP 460 DI 10.1016/S0009-2541(00)00220-5 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 349HN UT WOS:000089039800015 ER PT J AU Sagi, J Perry, A Hang, B Singer, B AF Sagi, J Perry, A Hang, B Singer, B TI Differential destabilization of the DNA oligonucleotide double helix by a T center dot G mismatch, 3,N-4-ethenocytosine, 3,N-4-ethanocytosine, or an 8-(Hydroxymethyl)-3,N-4-ethenocytosine adduct incorporated into the same sequence contexts SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID NMR SOLUTION STRUCTURE; THERMODYNAMIC PARAMETERS; CRYSTAL-STRUCTURE; BASE-PAIRS; REPAIR; GLYCOSYLASE; DUPLEX; STABILITY; 2'-DEOXYGUANOSINE; RECOGNITION AB The T.G mismatch and the exocyclic adduct 3,N-4-ethenocytosine (epsilon C) are repaired by the same enzyme, the human G/T(U) mismatch-DNA glycosylase (TDG). This enzyme removes the T, U, or epsilon C base from duplex DNA. The rate of cleavage was found to differ with the lesion and was also affected by neighbor sequences [Hang, B., Medina, M., Fraenkel-Conrat, H., and Singer, B. (1998) Proc. Natl. Acad. Sci. U.S.A. 95, 13561-13566]. Since sequence influences duplex stability, we determined the thermodynamic stability of T.G and epsilon C-containing 15-mer duplexes in which the bases flanking the lesion were systematically varied. The duplexes contained central 5'-TTXTT, 5'-AAXAA, 5'-CCXCC, or 5'-GGXGG sequences, where X is T, epsilon C, or two closely related structural derivatives of EC: 3,N-4-ethanocytosine (EC) and 8-(hydroxymethyl)-epsilon C (8-HM-epsilon C). Each of the four lesions, incorporated opposite G, decreased both the thermal (T,) and thermodynamic stability (Delta G degrees(37)) of the 15-mer control duplexes. On the basis of the T-m and Delta G degrees(37) values, the order of destabilization of the TTXTT sequence in 15-mer duplexes was as follows: 8-HM-epsilon C > EC > epsilon C > T.G. The Delta T-m values range from -15.8 to -9.5 degrees C when C-t = 8 mu M. Duplexes with flanking AA or TT neighbors were more destabilized, by an average of 2 degrees C, than those with flanking GG or CC neighbors. The base opposite the modified base also influenced duplex stability. Within the TT context, of the four changed bases opposite the adducts, C had the greatest destabilizing effect, up to -18.4 degrees C. In contrast, a G opposite an adduct was generally the least destabilizing, and the smallest value was -3.0 degrees C. Destabilizations were enthalpic in origin. Thus, this work shows that independently changing the modified base, the sequence, or the base opposite the lesion each affects the stability of the duplex, to significantly varying extents. The potential contribution of the thermodynamic stability to repair efficiency is discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Div Life Sci, Berkeley, CA 94720 USA. Hungarian Acad Sci, Chem Res Ctr, Inst Chem, H-1525 Budapest, Hungary. RP Singer, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Div Life Sci, Berkeley, CA 94720 USA. FU NCI NIH HHS [CA 47723, CA 72079] NR 38 TC 11 Z9 11 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD SEP PY 2000 VL 13 IS 9 BP 839 EP 845 DI 10.1021/tx000040g PG 7 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 356RZ UT WOS:000089457800005 PM 10995256 ER PT J AU Shen, ZH Bosbach, D Hochella, MF Bish, DL Williams, MG Dodson, RF Aust, AE AF Shen, ZH Bosbach, D Hochella, MF Bish, DL Williams, MG Dodson, RF Aust, AE TI Using in vitro iron deposition on asbestos to model asbestos bodies formed in human lung SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID SINGLE-STRAND BREAKS; CROCIDOLITE ASBESTOS; LIPID-PEROXIDATION; FERRUGINOUS BODIES; DNA; MOBILIZATION; CHELATORS; FIBERS; CARCINOGENICITY; MICROSOMES AB Recent studies have shown that iron is an important factor in the chemical activity of asbestos and may play a key role in its biological effects. The most carcinogenic forms of asbestos, crocidolite and amosite, contain up to 27% iron by weight as part of their crystal structure. These minerals can acquire more iron after being inhaled, thereby forming asbestos bodies. Reported here is a method for depositing iron on asbestos fibers in vitro which produced iron deposits of the same form as observed on asbestos bodies removed from human lungs. Crocidolite and amosite were incubated in either FeCl(2) or FeCl(3) solutions for 2 h. To assess the effect of longer-term binding, crocidolite was incubated in FeCl(2) or FeCl(3) and amosite in FeCl(3) for 14 days. The amount of iron bound by the fibers was determined by measuring the amount remaining in the incubation solution using an iron assay with the chelator ferrozine. After iron loading had been carried out, the fibers were also examined for the presence of an increased amount of surface iron using X-ray photoelectron spectroscopy (XPS). XPS analysis showed an increased amount of surface iron on both Fe(II)- and Fe(III)-loaded crocidolite and only on Fe(III)-loaded amosite. In addition, atomic force microscopy revealed that the topography of amosite, incubated in 1 mM FeCl(3) solutions for 2 h, was very rough compared with that of the untreated fibers, further evidence of Fe(III) accumulation on the fiber surfaces. Analysis of long-term Fe(III)-loaded crocidolite and amosite using X-ray diffraction (XRD) suggested that ferrihydrite, a poorly crystallized hydrous ferric iron oxide, had formed. XRD also showed that ferrihydrite was present in amosite-core asbestos bodies taken from human lung. Auger electron spectroscopy (AES) confirmed that Fe and O were the only constituent elements present on the surface of the asbestos bodies, although H cannot be detected by AES and is presumably also present. Taken together for all samples, the data reported here suggest that Fe(II) binding may result from ion exchange, possibly with Na, on the fiber surfaces, whereas Fe(III) binding forms ferrihydrite on the fibers under the conditions used in this study. Therefore, fibers carefully loaded with Fe(III) in vitro may be a particularly appropriate and useful model for the study of chemical characteristics associated with asbestos bodies and their potential interactions in a biosystem. C1 Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. Virginia Polytech Inst & State Univ, Dept Geol Sci, Blacksburg, VA 24061 USA. Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. Univ Texas Hlth Ctr, Dept Cell Biol & Environm Sci, Tyler, TX 75710 USA. RP Aust, AE (reprint author), Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. EM AAUST@cc.usu.edu RI Bosbach, Dirk/C-7764-2011 OI Bosbach, Dirk/0000-0002-6099-0400 FU NIEHS NIH HHS [ES05782] NR 47 TC 11 Z9 11 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD SEP PY 2000 VL 13 IS 9 BP 913 EP 921 DI 10.1021/tx000025b PG 9 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 356RZ UT WOS:000089457800014 PM 10995265 ER PT J AU Phuoc, TX AF Phuoc, TX TI Single-point versus multi-point laser ignition: Experimental measurements of combustion times and pressures SO COMBUSTION AND FLAME LA English DT Article ID SPARK-IGNITION; MIXTURES; FLAME AB It has been reported that when a laser beam of irradiance on the order of 10(10) W/cm(2) interacts with a gas, a spark plasma of high temperature (on the order 10(6) K) and pressure (on the order of 10(3) atm) is generated at the end of the laser pulse. This extreme condition leads to the development of a rapidly expanding shock wave that is strong enough to ignite a gaseous combustible mixture [1-8], liquid fuel sprays [9], or even to extinguish a diffusion flame [1]. Laser ignition is nonintrusive and is capable of providing center ignition and/or multiple ignition sites that can be programmed to ignite a combustible mixture either sequentially or simultaneously [10]. Because these advantages are potentially important for fuel-lean combustion and high-speed combustion applications, the present work was designed to study laser ignition of combustible gases using three different ignition configurations: multi-point ignition, single-wall ignition, and single-center ignition. In particular, we investigated the effects of these ignition configurations on ignition and combustion properties such as combustion pressure and time for H(2)air, and CH4/air mixtures. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Phuoc, TX (reprint author), US DOE, Natl Energy Technol Lab, POB 10940,MS 84-340, Pittsburgh, PA 15236 USA. NR 10 TC 42 Z9 44 U1 1 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD SEP PY 2000 VL 122 IS 4 BP 508 EP 510 DI 10.1016/S0010-2180(00)00137-1 PG 3 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 345NV UT WOS:000088822800013 ER PT J AU Hwang, P Fedkiw, RP Merriman, B Aslam, TD Karagozian, AR Osher, SJ AF Hwang, P Fedkiw, RP Merriman, B Aslam, TD Karagozian, AR Osher, SJ TI Numerical resolution of pulsating detonation waves SO COMBUSTION THEORY AND MODELLING LA English DT Article ID SCHEMES AB The canonical problem of the one-dimensional, pulsating, overdriven detonation wave has been studied for over 30 years, not only for its phenomenological relation to the evolution of multidimensional detonation instabilities, but also to provide a robust, reactive, high-speed flowfield with which to test numerical schemes. The present study examines this flowfield using high-order, essentially non-oscillatory schemes, systematically varying the level of resolution of the reaction zone, the size and retention of information in the computational domain, the initial conditions, and the order of the scheme. It is found that there can be profound differences in peak pressures as well as in the period of oscillation, not only for cases in which the reaction front is under-resolved, but for cases in which the computation is corrupted due to a too-small computational domain. Methods for estimating the required size of the computational domain to reduce costs while avoiding erroneous solutions are proposed and tested. C1 Univ Calif Los Angeles, Dept Mech & Aerosp Engn, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90095 USA. Los Alamos Natl Lab, Grp DX1, Los Alamos, NM USA. RP Karagozian, AR (reprint author), Univ Calif Los Angeles, Dept Mech & Aerosp Engn, Los Angeles, CA 90095 USA. EM peterh@seas.ucla.edu; fedkiw@cs.stanford.edu; barry@math.ucla.edu; aslam@lanl.gov; ark@seas.ucla.edu; sjo@math.ucla.edu NR 25 TC 37 Z9 40 U1 0 U2 7 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1364-7830 J9 COMBUST THEOR MODEL JI Combust. Theory Model. PD SEP PY 2000 VL 4 IS 3 BP 217 EP 240 DI 10.1088/1364-7830/4/3/301 PG 24 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Mathematics, Interdisciplinary Applications SC Thermodynamics; Energy & Fuels; Engineering; Mathematics GA 362GX UT WOS:000089771200001 ER PT J AU Ulitsky, M Ghenai, C Gokalp, I Wang, LP Collins, LR AF Ulitsky, M Ghenai, C Gokalp, I Wang, LP Collins, LR TI Comparison of a spectral model for premixed turbulent flame propagation to DNS and experiments SO COMBUSTION THEORY AND MODELLING LA English DT Article ID HIGH REYNOLDS-NUMBER; HIGH-RESOLUTION SIMULATIONS; ISOTROPIC TURBULENCE; PASSIVE SCALAR; 2-DIMENSIONAL TURBULENCE; AXISYMMETRIC TURBULENCE; FRONT PROPAGATION; VELOCITY-FIELD; FLOW; CURVATURE AB A recently developed spectral model for premixed turbulent combustion in the flamelet regime (based on the EDQNM turbulence theory) has been compared with both direct numerical simulations (DNS) and experimental data. The 128(3) DNS is performed at a Reynolds number of 223 based on the integral length scale. Good agreement is observed for both single- and two-point quantities (i.e. ratio of the turbulent to laminar burning velocities, scalar autocorrelation. dissipation and scalar-velocity cross correlation spectral for the two different values of u'/s(LO) considered. The model also predicts the rapid transient behaviour of the flame at early times. An experimental set-up is then described for generating a lean methane-ah flame and measuring two- point spatial correlations along the midpoint of the flame brush (i.e. along the (C) over bar = 0.5 contour). The experimental measurements in the flamelet regime take the form of a discontinuous or 'telegraph' signal. The EDQNM model, in contrast, describes an 'ensemble' of flames, and thus is based solely on continuous variables. A theoretical relationship between the correlation obtained from the EDQNM model and the equivalent correlation for a discontinuous (experimental) flame is derived. The relationship is used to enable a meaningful comparison between experimentally observed and model correlations. In general, the agreement is good for the three different cases considered in this study, with most of the error occurring at the lowest Reynolds number (Re-L = 22). Furthermore, it is shown that considerably more error would result if no attempt is made to convert the ensemble representation in the model to an equivalent single-flame or 'telegraph' signal. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Dept Mech & Aerosp Engn, Los Angeles, CA 90095 USA. CNRS, LCSR, F-45071 Orleans, France. Univ Delaware, Dept Mech Engn, Newark, DE 19716 USA. Penn State Univ, Dept Chem Engn, University Pk, PA 16802 USA. RP Collins, LR (reprint author), Univ Calif Los Alamos Natl Lab, MS B216,T-3, Los Alamos, NM 87545 USA. RI Wang, Lian-Ping/N-7516-2016 OI Wang, Lian-Ping/0000-0003-4276-0051 NR 54 TC 2 Z9 2 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1364-7830 J9 COMBUST THEOR MODEL JI Combust. Theory Model. PD SEP PY 2000 VL 4 IS 3 BP 241 EP 264 DI 10.1088/1364-7830/4/3/302 PG 24 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Mathematics, Interdisciplinary Applications SC Thermodynamics; Energy & Fuels; Engineering; Mathematics GA 362GX UT WOS:000089771200002 ER PT J AU Stubbs, L AF Stubbs, L TI DNA SO COMMENTARY LA English DT Letter C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Stubbs, L (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER JEWISH COMMITTEE PI NEW YORK PA 165 E 56TH ST, NEW YORK, NY 10022 USA SN 0010-2601 J9 COMMENTARY JI Commentary PD SEP PY 2000 VL 110 IS 2 BP 4 EP 4 PG 1 WC Political Science; Social Issues SC Government & Law; Social Issues GA 346HZ UT WOS:000088866100003 ER PT J AU Beyerlein, IJ AF Beyerlein, IJ TI Stress fields around cracks with a viscous matrix and discontinuous fiber bridging SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT International Mechanical Engineering Congress and Exhibition CY 1998 CL ANAHEIM, CALIFORNIA DE polymer matrix composites; defects; crack; stress concentration; viscoelasticity ID TIME EVOLUTION; COMPOSITE; PROFILES; FAILURE AB In this work, effects of pre-existing fiber fractures on the time-dependent stress redistribution and opening displacements within a planar unidirectional fiber composite under steady axial tension are investigated. Shear deformation of a Newtonian viscous matrix material or interface is assumed to govern the local creep response, while the fibers have time-independent elastic properties. Under these assumptions, the recently developed computational-mechanics technique called viscous break interaction (VBI) is used to efficiently compute the time-dependent stress and strain redistribution in the fibers and matrix in response to any number and spatial configuration of fiber breaks. As typically observed in the intermediate stages of composite creep failure, bridged cracks, cracks with process zones, and mis-aligned, staggered breaks are studied using VBI. Asymptotic relations are developed for the time evolution of opening displacements of large cracks and bridged cracks, whose predictions agree well with VBI results. For staggered breaks, some important differences emerge. Results show how time-growing interactions between staggered breaks and the spatial arrangement and number of such breaks influence local creep rate, fiber tensile stress redistribution, and macroscopically, the timescales of multiple creep stages in overall composite strain. This VRI technique and insight developed here into the time-dependent deformation and stress concentration behavior are particularly useful in modeling the statistical evolution of creep failure mechanisms and for incorporating into computational codes for predicting time-to-failure. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Beyerlein, IJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Mail Stop G755, Los Alamos, NM 87545 USA. RI Beyerlein, Irene/A-4676-2011 NR 15 TC 9 Z9 10 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PD SEP-OCT PY 2000 VL 60 IS 12-13 SI SI BP 2309 EP 2326 DI 10.1016/S0266-3538(00)00027-0 PG 18 WC Materials Science, Composites SC Materials Science GA 370EY UT WOS:000165111600011 ER PT J AU Pellat, R Le Contel, O Roux, A Perraut, S Hurricane, OH Coroniti, FV Luciani, JF AF Pellat, R Le Contel, O Roux, A Perraut, S Hurricane, OH Coroniti, FV Luciani, JF TI A new approach for magnetospheric substorms SO COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE IV PHYSIQUE ASTROPHYSIQUE LA French DT Article DE magnetospheric substorms; reconfiguration of the magnetic field; magnetic field-aligned current ID PLASMA SHEET; FREQUENCY AB In a previous report we had started a systematic study of the ballooning modes as the natural waves of the magnetospheric turbulence substorm and reconnection. After many new results following from the very high mirror ratio of the magnetospheric plasma, summarized in this note, we explain the fundamental vole of ion cyclotron instabilities generated by the closure of confinement currents, by field-aligned currents in a three-dimensional (3D) configurations resulting from the growth phase and (or) ballooning modes. These instabilities destroy the current system, dipolarize the magnetic field and ave consequently the non linear missing piece of substorm phenomenology. An indirect proof of this theory (apart fi om observational evidence) is found in the fast heating of electrons, the so-called 'dispersionless injection' and a smaller effect on the proton population (diffusion coefficients are in the minutes time scale for protons and seconds for electrons!). This magnetospheric mechanism is very likely operating in solar flares and is in fact an added stone to a 3D time-dependent reconnection and acceleration. (C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevier SAS. C1 CEA, F-75007 Paris, France. Ctr Etud Environm Terr & Planetaires, F-78140 Velizy, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Ecole Polytech, Ctr Phys Theor, F-91128 Palaiseau, France. RP Le Contel, O (reprint author), CEA, Rue Federat, F-75007 Paris, France. NR 9 TC 2 Z9 2 U1 0 U2 2 PU EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS CEDEX 15 PA 23 RUE LINOIS, 75724 PARIS CEDEX 15, FRANCE SN 1296-2147 J9 CR ACAD SCI IV-PHYS JI C. R. Acad. Sci. Ser. IV-Phys. Astrophys. PD SEP PY 2000 VL 1 IS 7 BP 975 EP 980 DI 10.1016/S1296-2147(00)01105-7 PG 6 WC Astronomy & Astrophysics; Physics, Multidisciplinary SC Astronomy & Astrophysics; Physics GA 373JK UT WOS:000165285600011 ER PT J AU Bertram, M Barnes, JC Hamann, B Joy, KI Pottmann, H Wushour, D AF Bertram, M Barnes, JC Hamann, B Joy, KI Pottmann, H Wushour, D TI Piecewise optimal triangulation for the approximation of scattered data in the plane SO COMPUTER AIDED GEOMETRIC DESIGN LA English DT Article DE triangulation; data-dependent triangulation; approximation; hierarchical approximation; quadratic polynomials; clustering AB We present an efficient algorithm to obtain a triangulated graph surface for scattered points (x(i) y(i))(T), i = 1,..., n, with associated function values f(i). The maximal distance between the triangulated graph surface and the function values is measured in z-direction (z = f(x, y)) and lies within a user-defined tolerance. The number of triangles is minimized locally by adapting their shapes to different second-degree least squares approximations of the underlying data. The method consists of three major steps: (i) subdividing the given discrete data set into clusters such that each cluster can be approximated by a quadratic polynomial within a prescribed tolerance; (ii) optimally triangulating the graph surface of each quadratic polynomial; and (iii) "stitching" the triangulations of all graph surfaces together. We also discuss modifications of the algorithm that are necessary to deal with discrete data points, without connectivity information, originating from a general two-manifold surface, i.e., a surface in three-dimensional space that is not necessarily a graph surface. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Vienna Univ Technol, Inst Geometrie, A-1040 Vienna, Austria. RP Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808, Livermore, CA 94551 USA. EM bertram@cs.ucdavis.edu NR 31 TC 9 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8396 EI 1879-2332 J9 COMPUT AIDED GEOM D JI Comput. Aided Geom. Des. PD SEP PY 2000 VL 17 IS 8 BP 767 EP 787 DI 10.1016/S0167-8396(00)00026-1 PG 21 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 351TU UT WOS:000089174900003 ER PT J AU Montgomery, M de Veciana, G AF Montgomery, M de Veciana, G TI Hierarchical source routing using implied costs SO COMPUTER NETWORKS-THE INTERNATIONAL JOURNAL OF COMPUTER AND TELECOMMUNICATIONS NETWORKING LA English DT Article DE hierarchical source routing; network aggregation; implied costs; revenue sensitivities; adaptive routing ID CIRCUIT-SWITCHED NETWORKS; BLOCKING PROBABILITIES; OPTIMIZATION; QUALITY AB Based on a loss network model, we present an adaptive source routing scheme for a large, hierarchically organized network. To represent the "available" capacity of a peer group (subnetwork), we compute the average implied cost to go through or into the peer group. Such implied costs reflect the congestion in the peer group as well as the interdependencies among traffic streams in the network. We prove that both a synchronous and asynchronous distributed computation of the implied costs will converge to a unique solution under a light load condition. Furthermore, we present a more aggressive averaging mechanism that, with sufficient damping, will converge to a unique solution under any traffic conditions. One of the key features of this paper is an attempt to quantify routing "errors" due to inaccuracies caused by aggregation. In fact, our experimental results show that these approximations are reasonably accurate and our scheme is able to appropriately route high level flows while significantly reducing complexity. In addition, we show how on-line measurements and multiservice extensions can be incorporated into the routing algorithm. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Adv Technol Directorate, Ctr Informat Infrastruct Technol, Oak Ridge, TN 37830 USA. Univ Texas, Dept Elect & Comp Engn, Austin, TX 78712 USA. RP Montgomery, M (reprint author), Adv Technol Directorate, Ctr Informat Infrastruct Technol, DOE Y-12,1099 Commerce Pk, Oak Ridge, TN 37830 USA. NR 51 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1389-1286 J9 COMPUT NETW JI Comput. Netw. PD SEP PY 2000 VL 34 IS 3 BP 379 EP 397 DI 10.1016/S1389-1286(00)00119-5 PG 19 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 346WM UT WOS:000088894100004 ER PT J AU Klintenberg, M Derenzo, SE Weber, MJ AF Klintenberg, M Derenzo, SE Weber, MJ TI Accurate crystal fields for embedded cluster calculations SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE embedded cluster calculation; crystal field potential; Ewald potential AB Local electronic structure defects in ionic crystals is commonly modeled using embedded cluster calculations. In this context we describe how to embed the quantum cluster (QC) in an array of point charges. Specifically, the method calculates an array of point charges that reproduces the electrostatic potential of the infinite crystal within an accuracy usually < 1 mu V in the interior of the QC. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Klintenberg, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd 55-121, Berkeley, CA 94720 USA. NR 9 TC 28 Z9 28 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD SEP 1 PY 2000 VL 131 IS 1-2 BP 120 EP 128 DI 10.1016/S0010-4655(00)00071-0 PG 9 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 351UA UT WOS:000089175500011 ER PT J AU Siantar, CLH Garrett, D AF Siantar, CLH Garrett, D TI Photon-beam radiation therapy and Monte Carlo SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article ID DOSIMETRY; SYSTEM AB Because small variations in radiation doses can cause significant changes in clinical outcome, calculation accuracy is a major factor in the success or failure of a cancer treatment course. This article describes how stochastic, Monte Carlo radiation transport methods can predict radiation doses for cancer patients. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Siantar, CLH (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L174, Livermore, CA 94550 USA. NR 22 TC 1 Z9 1 U1 1 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD SEP-OCT PY 2000 VL 2 IS 5 BP 31 EP 38 DI 10.1109/5992.877388 PG 8 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 353PD UT WOS:000089283900006 ER PT J AU Chen, JB Angelici, RJ AF Chen, JB Angelici, RJ TI Remarkable transformations of thiophene ligands in their pentamethylcyclopentadienyl iridium (Cp*Ir) complexes SO COORDINATION CHEMISTRY REVIEWS LA English DT Review DE thiophene ligands; pentamethylcyclopentadienyl iridium complexes; dibenzothiophene complexes ID TRANSITION-METAL COMPLEXES; COORDINATED THIOPHENE; 2,5-DIMETHYLTHIOPHENE COORDINATION; MICROWAVE-SPECTRUM; INTERNAL-ROTATION; BASE HYDROLYSIS; HDS CATALYSTS; TRIPLE BOND; S-BONDS; HYDRODESULFURIZATION AB The cationic eta(5)-2,5-dimethylthiophene complex Cp*Ir(eta(5)-2,5-Me2T)(2+) (1) is the entry point for the synthesis of a variety of complexes resulting from nucleophilic attack on or reduction of 1. Reduction gives Cp*Ir(eta(4)-2,5-Me2T) (4), in which the thiophene ligand is coordinated through only the four carbon atoms, and its isomer Cp*Ir(C,S-2,5-Me2T) (5) in which there is a six-membered aromatic ring incorporating the original thiophene and iridium. These isomers undergo a range of reactions with Lewis acids, bases, and mono- and polynuclear transition metal complexes. Analogous studies of benzo[b]thiophene and dibenzothiophene complexes are also reviewed. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Chinese Acad Sci, Shanghai Inst Organ Chem, Organomet Chem Lab, Shanghai 200032, Peoples R China. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Chen, JB (reprint author), Chinese Acad Sci, Shanghai Inst Organ Chem, Organomet Chem Lab, 354 Fenglin Lu, Shanghai 200032, Peoples R China. NR 66 TC 41 Z9 41 U1 1 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0010-8545 J9 COORDIN CHEM REV JI Coord. Chem. Rev. PD SEP PY 2000 VL 206 BP 63 EP 99 DI 10.1016/S0010-8545(99)00250-7 PG 37 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 363MT UT WOS:000089839800003 ER PT J AU Speth, TF Gusses, AM Summers, RS AF Speth, TF Gusses, AM Summers, RS TI Evaluation of nanofiltration pretreatments for flux loss control SO DESALINATION LA English DT Article DE nanofiltration; membranes; flux; foulants; drinking water; autopsy; biofouling ID REVERSE-OSMOSIS MEMBRANES; MASS-SPECTROMETRY; SURFACE-WATER; MICROFILTRATION; ULTRAFILTRATION AB The loss of membrane flux due to fouling is a major impediment to the development of membrane processes for use in drinking water treatment. The objective of this work was to evaluate fouling in nanofiltration (NF) pilot systems fed conventionally-treated (coagulation/sedimentation/filtration) Ohio River water (CT-ORW) with various additional levels of pretreatment. The chosen additional pretreatments were intended to produce waters with varying biological-fouling potential. Five parallel membranes were fed CT-ORW, ozonated CT-ORW, ozonated/biofiltered CT-ORW, CT-ORW reduced to 7 degrees C, and chloraminated CT-ORW. All systems showed significant flux decline indicating that methods beyond those needed for just biogrowth control are required for NF systems treating conventionally-treated surface waters. The NF systems fed ozonated, ozonated/biofiltered, and untreated CT-ORW had the least amount of flux decline over the course of the study; however, they had significant amounts of biological growth. Fouling in these systems was attributed to the deposition of extracellular material (polysaccharides) in the cake layer, either from the biogrowth on the membrane or carryover from the pretreatment. The low-temperature system had greater flux decline, but it had lower biogrowth than the ozonated, and ozonated/biofiltered and untreated CT-ORW systems. Although lower in biogrowth, the deposited organic material in the low-temperature system still showed a strong biological signature (polysaccharides and aminosugars). The chloraminated system had the greatest flux decline, but the least amount of biogrowth. The organic material deposited in the chloraminated system showed a high level of proteinaceous character. C1 US EPA, Cincinnati, OH 45268 USA. US EPA, Oak Ridge Inst Sci & Educ, Cincinnati, OH 45268 USA. Univ Colorado, Boulder, CO 80309 USA. RP Speth, TF (reprint author), US EPA, 26 W Martin Luther King Dr, Cincinnati, OH 45268 USA. NR 33 TC 43 Z9 44 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0011-9164 J9 DESALINATION JI Desalination PD SEP 1 PY 2000 VL 130 IS 1 BP 31 EP 44 DI 10.1016/S0011-9164(00)00072-2 PG 14 WC Engineering, Chemical; Water Resources SC Engineering; Water Resources GA 352FB UT WOS:000089202900003 ER PT J AU Cannon, SH Reneau, SL AF Cannon, SH Reneau, SL TI Conditions for generation of fire-related debris flows, Capulin Canyon, New Mexico SO EARTH SURFACE PROCESSES AND LANDFORMS LA English DT Article DE debris flow; wildfire; erosion ID WILDFIRE; USA AB Comparison of the responses of three drainage basins burned by the Dome fire of 1996 in New Mexico is used to identify the hillslope, channel and fire characteristics that indicate a susceptibility specifically to wildfire-related debris flow. Summer thunderstorms generated three distinct erosive responses from each of three basins. The Capulin Canyon basin showed widespread erosive sheetwash and rilling from hillslopes, and severe flooding occurred in the channel; the North Tributary basin exhibited extensive erosion of the mineral soil to a depth of 5 cm and downslope movement of up to boulder-sized material, and at least one debris flow occurred in the channel; negligible surface runoff was observed in the South Tributary basin. The negligible surface runoff observed in the South Tributary basin is attributed to the limited extent and severity of the fire in that basin. The factors that best distinguish between debris-flow producing and flood-producing drainages are drainage basin morphology and lithology. A rugged drainage basin morphology, an average 12 per cent channel gradient, and steep, rough hillslopes coupled with colluvium and soil weathered from volcaniclastic and volcanic rocks promoted the generation of debris flows. A less rugged basin morphology, an average gradient of 5 per cent, and long, smooth slopes mantled with pumice promoted flooding. Flood and debris-flow responses were produced without the presence of water-repellent soils. The continuity and severity of the burn mosaic, the condition of the riparian vegetation, the condition of the fibrous root mat, accumulations of dry ravel and colluvial material in the channel and on hillslopes, and past debris-flow activity, appeared to have little bearing on the distinctive responses of the basins. Published in 2000 by John Wiley & Sons, Ltd. C1 US Geol Survey, Denver Fed Ctr, Hazards Team, Denver, CO 80225 USA. Univ Calif Los Alamos Natl Lab, Geol & Geochem Grp, Los Alamos, NM 87545 USA. RP Cannon, SH (reprint author), US Geol Survey, Denver Fed Ctr, Hazards Team, Box 25046,MS 966, Denver, CO 80225 USA. NR 38 TC 66 Z9 68 U1 1 U2 7 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0197-9337 J9 EARTH SURF PROC LAND JI Earth Surf. Process. Landf. PD SEP PY 2000 VL 25 IS 10 BP 1103 EP 1121 DI 10.1002/1096-9837(200009)25:10<1103::AID-ESP120>3.0.CO;2-H PG 19 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 355PD UT WOS:000089393300004 ER PT J AU Barton, C Nelson, EA Kolka, RK McLeod, KW Conner, WH Lakly, M Martin, D Wigginton, J Trettin, CC Wisniewski, J AF Barton, C Nelson, EA Kolka, RK McLeod, KW Conner, WH Lakly, M Martin, D Wigginton, J Trettin, CC Wisniewski, J TI Restoration of a severely impacted riparian wetland system - The Pen Branch Project SO ECOLOGICAL ENGINEERING LA English DT Editorial Material C1 US Forest Serv, Ctr Forested Wetlands Res, USDA, SREL, Aiken, SC 29802 USA. Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29802 USA. Univ Kentucky, Dept Forestry, Lexington, KY 40546 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Clemson Univ, Baruch Forest Sci Inst, Georgetown, SC 29442 USA. Univ Georgia, Inst Ecol, Athens, GA 30602 USA. Auburn Univ, Sch Forestry, Auburn, AL 36849 USA. Wisniewski & Associates Inc, Falls Church, VA USA. RP Barton, C (reprint author), US Forest Serv, Ctr Forested Wetlands Res, USDA, SREL, Drawer E, Aiken, SC 29802 USA. NR 31 TC 1 Z9 1 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD SEP PY 2000 VL 15 SU 1 BP S3 EP S15 DI 10.1016/S0925-8574(99)00084-1 PG 13 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA 369AY UT WOS:000090150700002 ER PT J AU Fletcher, DE Wilkins, SD McArthur, JV Meffe, GK AF Fletcher, DE Wilkins, SD McArthur, JV Meffe, GK TI Influence of riparian alteration on canopy coverage and macrophyte abundance in Southeastern USA blackwater streams SO ECOLOGICAL ENGINEERING LA English DT Article; Proceedings Paper CT Workshop on Restoration of a Severely Impacted Southeastern Riparian Wetland Systems - the Pen Branch Project CY APR 12-14, 1999 CL CLEMSON UNIV, CLEMSON, SOUTH CAROLINA HO CLEMSON UNIV DE riparian; disturbance; macrophytes; canopy; stream; thermal effluents; Savannah River ID AQUATIC MACROPHYTES; COMMUNITIES; ENVIRONMENT; ECOSYSTEM AB Two tributary streams (Fourmile branch and Pen branch) located on the US Department of Energy's Savannah river site in west-central South Carolina, USA received thermal discharges from nuclear production reactors for over 30 years. Effluent releases produced stream water temperatures of over 50 degreesC and stream flows of ten times above their base level. Consequently, existing plant and animal communities within the stream channels were killed and riparian zones largely destroyed. We compared canopy coverage and macrophyte abundance in these disturbed streams after 7-13 years of ambient flows and compared them to two similar, undisturbed streams. We also examined the effects of a more recent woody canopy removal associated with a restoration effort in 'treated' sections of Pen branch. We collected data in Spring and Fall from May 1995 through May 1997. A gradient in canopy cover existed, ranging from a fully open herbaceous canopy in the treated sections of Pen branch, through a moderately closed canopy of herbaceous plants, shrubs, and willows in the post-thermal 'control' streams, to a nearly closed hardwood tree canopy in the undisturbed streams. Even though Fourmile branch had 3 more years of growth, Pen branch had a more closed upper canopy. Total aquatic macrophyte abundance was negatively related to canopy cover producing nearly the reverse gradient among streams as did the canopy cover. However, control sections of Pen branch had a more closed canopy than Fourmile branch, but total macrophyte abundance was higher in Pen branch. This can be attributed to the presence of submergent macrophytes in Pen branch that were absent in Fourmile branch. Different structural types of macrophytes varied in their degree of limitation by canopy coverage and in their seasonal patterns of growth. Stream habitats remain severely altered due to destruction of the riparian vegetation by past thermal effluents. The full range of effects of the alteration of canopy coverage and the resultant macrophyte abundances on these streams should be the focus of future analyses. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Florida, Dept Wildlife Ecol & Conservat, Gainesville, FL 32611 USA. RP Fletcher, DE (reprint author), Univ Georgia, Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. NR 32 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD SEP PY 2000 VL 15 SU 1 BP S67 EP S78 DI 10.1016/S0925-8574(99)00073-7 PG 12 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA 369AY UT WOS:000090150700008 ER PT J AU Lakly, MB McArthur, JV AF Lakly, MB McArthur, JV TI Macroinvertebrate recovery of a post-thermal stream: habitat structure and biotic function SO ECOLOGICAL ENGINEERING LA English DT Article; Proceedings Paper CT Workshop on Restoration of a Severely Impacted Southeastern Riparian Wetland Systems - the Pen Branch Project CY APR 12-14, 1999 CL CLEMSON UNIV, CLEMSON, SOUTH CAROLINA HO CLEMSON UNIV DE invertebrate; stream; recovery; thermal effluent; macrophyte; snag; functional feeding group; family biotic index; taxa richness ID BLACKWATER RIVER; BIOFILM DEVELOPMENT; WOOD; COLONIZATION AB Macroinvertebrate faunal assemblages, organic matter availability and instream structural complexity were investigated in three systems to determine the current state of recovery of a post-thermal stream. The abundance and diversity of the lower foodchain community has recovered substantially since cessation of thermal flows in 1988; however, the biotic communities remain structurally and functionally distinct as a result of past thermal perturbation. Disparate instream habitat structural components and stream physical changes in the post-thermal and reference systems drive functional differences in the macroinvertebrate community. The post-thermal stream is physically and biologically structured by high densities of aquatic macrophytes, while the reference system is driven by high concentrations of coarse woody debris. Consequently, the abundant, diverse macroinvertebrate communities in both systems illustrate a post-thermal shift in energy source from a reliance on allochthonous to autochthonous inputs. Biotic indices such as taxa richness, a family level index and similarity index may not be sufficient to determine functional changes as a result of thermal impacts. However, the distribution of diverse functional feeding groups across streams was successful at characterizing divergence in resource utilization and processing. This distinction between macroinvertebrates' abundance and diversity, and their function in the ecosystem is essential in establishing relevant mitigation plans and endpoints for stream restoration. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Georgia, Inst Ecol, Athens, GA 30602 USA. Savannah River Ecol Lab, Aiken, SC 29801 USA. RP Lakly, MB (reprint author), Univ Georgia, Inst Ecol, Athens, GA 30602 USA. NR 27 TC 12 Z9 12 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD SEP PY 2000 VL 15 SU 1 BP S87 EP S100 DI 10.1016/S0925-8574(99)00075-0 PG 14 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA 369AY UT WOS:000090150700010 ER PT J AU Mayer, JJ Nelson, EA Wike, LD AF Mayer, JJ Nelson, EA Wike, LD TI Selective depredation of planted hardwood seedlings by wild pigs in a wetland restoration area SO ECOLOGICAL ENGINEERING LA English DT Article; Proceedings Paper CT Workshop on Restoration of a Severely Impacted Southeastern Riparian Wetland Systems - the Pen Branch Project CY APR 12-14, 1999 CL CLEMSON UNIV, CLEMSON, SOUTH CAROLINA HO CLEMSON UNIV DE hardwood seedlings; wild pigs; Sus scrofa; depredation; wetland restoration; Savannah River ID RANGE AB Following the planting of several thousand hardwood seedlings in a 69-ha wetland restoration area in west-central South Carolina, USA, wild pigs (Sus scrofa) depredated a large percentage of the young trees. This planting was undertaken as part of a mitigation effort to restore a bottomland hardwood community in the corridor and delta of a third order stream that had been previously impacted by the discharge of heated nuclear reactor effluent. The depredated restoration areas had been pretreated with both herbicide and control burning prior to planting the hardwood seedlings. After discovery of the wild pig damage, these areas were surveyed on foot to assess the magnitude of the depredation on the planted seedling crop. Foraging by the local wild pigs in the pretreatment areas selectively impacted only four of the nine hardwood species used in this restoration effort. Based on the surveys, the remaining five species did not appear to have been impacted at all. A variety of reasons could be used to explain this phenomenon. The pretreatment methodology is thought to have been the primary aspect of the restoration program that initially led the wild pigs to discover the planted seedlings. In addition, it is possible that a combination of other factors associated with odor and taste may have resulted in the selective depredation. Future wetland restoration efforts in areas with wild pigs should consider pretreatment methods and species to be planted. If pretreatment methods and species such as discussed in the present study must be used, then the prior removal of wild pigs from surrounding lands will help prevent depredations by this non-native species. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Westinghouse Savannah River Co, Environm Protect Dept, Aiken, SC 29808 USA. Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Mayer, JJ (reprint author), Westinghouse Savannah River Co, Environm Protect Dept, POB 616, Aiken, SC 29808 USA. NR 25 TC 10 Z9 11 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD SEP PY 2000 VL 15 SU 1 BP S79 EP S85 DI 10.1016/S0925-8574(99)00074-9 PG 7 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA 369AY UT WOS:000090150700009 ER PT J AU McLeod, KW AF McLeod, KW TI Species selection trials and silvicultural techniques for the restoration of bottomland hardwood forests SO ECOLOGICAL ENGINEERING LA English DT Article; Proceedings Paper CT Workshop on Restoration of a Severely Impacted Southeastern Riparian Wetland Systems - the Pen Branch Project CY APR 12-14, 1999 CL CLEMSON UNIV, CLEMSON, SOUTH CAROLINA HO CLEMSON UNIV DE wetland restoration; bottomland forest; hydrology; Savannah River; Pen Branch AB Since 1990, a series of experiments has examined the appropriateness of 24 tree species for restoring a bottomland and swamp forest in the delta of Fourmile Branch in the coastal plain of South Carolina, USA. In addition, various silvicultural techniques used to maximize the survival of tree plantings, have been appraised for effectiveness. While the topographic relief on the delta is small (dm differences between most sites), it is sufficient to utilize woody species with different flood tolerances. Hence, a diverse forest community can be established, using these elevation differences. In the wettest sites where water persists virtually continuously and may be one to two meters deep during large flood events, only the most flood-tolerant species, such as Taxodium distichum and Nyssa aquatica, can survive. These species will also survive very well at higher elevations, because the permanent water table never fell below one meter deep. In sites that are not flooded, unless the entire swamp is flooded, several additional species can be used. These include Fraxinus pennsylvanica, Carya aquatica, and Quercus lyrata. Finally, in slightly higher areas, Q. michauxii, Q. nuttallii and Q. phellos would have adequate survival. To minimize herbivory and maximize survival, tree shelters should be used if herbivore pressure is high. The prime herbivore of concern is beaver. Thus, any plantings that are frequently flooded may require protection. Other silvicultural techniques, including fertilization and control of herbaceous and willow competition, were not essential to ensure growth and survival. Finally, survival of the least expensive planting stock, bare root saplings, was nearly as good as balled and burlapped stock. Thus, unless absolute maximal survival is required, bare root stock will produce good survival at a fraction of the cost. One critical characteristic of the bare root stock is height, which must exceed the hood depth during the growing season. In the case of the Fourmile Branch delta, this was at least 45-60 cm tall. Published by Elsevier Science B.V. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP McLeod, KW (reprint author), Univ Georgia, Savannah River Ecol Lab, PO Drawer E, Aiken, SC 29802 USA. NR 21 TC 9 Z9 11 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD SEP PY 2000 VL 15 SU 1 BP S35 EP S46 DI 10.1016/S0925-8574(99)00070-1 PG 12 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA 369AY UT WOS:000090150700005 ER PT J AU Nelson, EA Dulohery, NC Kolka, RK McKee, WH AF Nelson, EA Dulohery, NC Kolka, RK McKee, WH TI Operational restoration of the Pen Branch bottomland hardwood and swamp wetlands - the research setting SO ECOLOGICAL ENGINEERING LA English DT Article; Proceedings Paper CT Workshop on Restoration of a Severely Impacted Southeastern Riparian Wetland Systems - the Pen Branch Project CY APR 12-14, 1999 CL CLEMSON UNIV, CLEMSON, SOUTH CAROLINA HO CLEMSON UNIV DE wetland restoration; Pen Branch; mitigation; bottomland hardwoods; site preparation; planting; riparian; swamp habitats; Savannah River AB The Savannah River swamp, a 3020 ha forested wetland on the floodplain of the Savannah River, USA is located on the Department of Energy's Savannah River site (SRS) near Aiken, SC. Historically, the swamp consisted of approximately 50% bald cypress-water tupelo (Taxodium distichum-Nyssa aquatica) stands, 40% mixed bottomland hardwood stands, and 10% shrub, marsh, and open water. Creek corridors were typical of southeastern bottomland hardwood forests. Hydrology was controlled by flooding of the Savannah River and by flow from four creeks that drain into the swamp prior to flow into the Savannah River. Upstream darns have caused some alteration of the water levels and timing of flooding within the floodplain. Major impacts to the swamp hydrology occurred with the completion of the production reactors and one coal-fired powerhouse at the SRS in the early 1950s. Flow in one of the tributaries, Pen Branch, was typically 0.3 m(3) s(-1) (10-20 cfs) prior to reactor pumping and 11.0 m(3) s(-1) (400 cfs) during pumping from 1954 to 1988. Sustained increases in water volume resulted in overflow of the original stream banks, the creation of additional floodplains, considerable erosion of the original stream corridor, and deposition of a deep silt layer on the newly formed delta. Heated water was discharged directly into Pen Branch and water temperature in the stream often exceeded 65 degreesC. The nearly continuous flooding of the swamp, the thermal load of the water, and the heavy silting resulted in complete mortality of the original vegetation in large areas of the floodplain. In the years since pumping was reduced, no volunteer seedlings of heavy-seeded hardwoods or cypress have been found in the floodplain corridor. Research was conducted to determine methods to reintroduce tree species characteristic of more mature forested wetlands. Species composition and selection were altered based on the current and expected hydrological regimes that the reforestation areas will be experiencing. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. Jefferson Smurfit Corp, Forest Res Ctr, Callahan, FL 32011 USA. Univ Kentucky, Dept Forestry, Lexington, KY 40546 USA. US Forest Serv, Dunlap, TN 37327 USA. RP Nelson, EA (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. NR 11 TC 4 Z9 4 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD SEP PY 2000 VL 15 SU 1 BP S23 EP S33 DI 10.1016/S0925-8574(99)00069-5 PG 11 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA 369AY UT WOS:000090150700004 ER PT J AU Wike, LD Martin, FD Hanlin, HG Paddock, LS AF Wike, LD Martin, FD Hanlin, HG Paddock, LS TI Small mammal populations in a restored stream corridor SO ECOLOGICAL ENGINEERING LA English DT Article; Proceedings Paper CT Workshop on Restoration of a Severely Impacted Southeastern Riparian Wetland Systems - the Pen Branch Project CY APR 12-14, 1999 CL CLEMSON UNIV, CLEMSON, SC HO CLEMSON UNIV DE small mammals; wetland restoration; riparian habitat ID SIGMODON-HISPIDUS; COTTON RAT; COMMUNITIES AB An opportunity to study the response of a small mammal community to restoration of a riparian wetland was provided by the Pen branch project at the Savannah river site (SRS). Live trapping of small mammals was conducted on six transects at Pen branch in 1996 and 1998 and at three transects at Meyers branch, an unimpacted stream at SRS, in 1997 and 1998. Distributions of rates of capture of the four most common species were both spatially and temporally uneven. Kruskal-Wallis one-way analysis of variance revealed no significant differences in the relationship of capture rates between species and between treatment and both the within-stream control and Meyers branch. Habitat use and movement within stream corridors appears to be dependent primarily on species, with age and sex perhaps contributing to habitat preference and distance moved. The lack of differences in capture rates related to transect or treatment may be due to the close proximity of sample transects relative to the movement potential of the species sampled. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. Univ S Carolina, Dept Biol & Geol, Aiken, SC 29801 USA. RP Wike, LD (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. EM lynn.wike@srs.gov NR 18 TC 5 Z9 5 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 EI 1872-6992 J9 ECOL ENG JI Ecol. Eng. PD SEP PY 2000 VL 15 SU 1 BP S121 EP S129 DI 10.1016/S0925-8574(99)00078-6 PG 9 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA 369AY UT WOS:000090150700013 ER PT J AU Bailey, CG Wallenborg, SR AF Bailey, CG Wallenborg, SR TI Indirect laser-induced fluorescence detection of explosive compounds using capillary electrochromatography and micellar electrokinetic chromatography SO ELECTROPHORESIS LA English DT Article DE capillary electrochromatography; indirect detection; explosives; micellar electrokinetic capillary chromatography ID ZONE-ELECTROPHORESIS; ELECTROCHEMICAL DETECTION; LIQUID-CHROMATOGRAPHY; SENSITIVITY; SEPARATION; NITRAMINE AB Mixtures of nitroaromatic and nitramine explosive compounds and their degradation products were analyzed using electrokinetically driven separations with both indirect laser-induced fluorescence (IDLIF) and UV absorption detection. Complete separations of the 14-component mixture (EPA 8330) were achieved using both capillary electrochromatography (CEC) and micellar electrokinetic chromatography (MEKC). IDLIF detection was performed using an epifluorescence system with excitation provided by a 635 nm diode laser and micromolar concentrations of the dye Cy-5 as the visualizing agent. While the sensitivity of the two detection methods was similar for the nitroaromatic compounds, the nitramines could only be detected using UV absorption due to their low fluorescence quenching efficiency of Cy-5. The detection sensitivity using IDLIF was limited by low frequency oscillations in the fluorescence background. The oscillations increased with higher electric field strength and were attributed to thermal fluctuations caused by Joule heating. Due to the more conductive running buffer and higher separation currents used in MEKC, sensitive IDLIF detection could only be achieved using low (similar to 100 V/cm) field strengths, resulting in long analysis times. CEC separations, which are typically run with low conductivity mobile phases to avoid bubble formation, are less sensitive to this effect. In CEC separations with IDLIF detection a stable fluorescence background using Cy-5 could be established using only a nonporous stationary phase. In capillaries packed with porous silica particles, anomalous migration behavior was observed with charged dye molecules and a stable fluorescence background could not be established under electrokinetic flow. This is the first demonstration of IDLIF in packed channel CEC. C1 Sandia Natl Labs, Chem & Radiat Detect Lab, Livermore, CA 94551 USA. RP Bailey, CG (reprint author), Sandia Natl Labs, Chem & Radiat Detect Lab, POB 969,MS 9671, Livermore, CA 94551 USA. NR 29 TC 33 Z9 36 U1 1 U2 11 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD SEP PY 2000 VL 21 IS 15 BP 3081 EP 3087 DI 10.1002/1522-2683(20000901)21:15<3081::AID-ELPS3081>3.0.CO;2-R PG 7 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 354FC UT WOS:000089318300003 PM 11001203 ER PT J AU Breadmore, MC Haddad, PR Fritz, JS AF Breadmore, MC Haddad, PR Fritz, JS TI Modelling and optimization of the separation of anions in ion chromatography-capillary electrophoresis SO ELECTROPHORESIS LA English DT Article DE modelling optimization; ion exchange; electrokinetic chromatography electrochromatography; polymer ID EXCHANGE ELECTROKINETIC CHROMATOGRAPHY; ZONE-ELECTROPHORESIS; CATIONIC POLYMERS; ELECTROCHROMATOGRAPHY; SELECTIVITY; MOBILITIES AB The influence of varying experimental conditions on the mobilities of inorganic and organic anions in ion chromatography-capillary electrophoresis (IC-CE) was studied. A theoretical model derived from both IC and CE was used to explain the influence on analyte mobility caused by varying the concentration of polymer and increasing the salt concentration in the background electrolyte. The influence of the type of competing ion was also accounted for by including the analyte selectivity coefficient in the model equation. The validity of the model was shown using electrolyte systems containing four different competing anions, with correlation between experimental and mobilities predicted being excellent (r(2) > 0.98) for all systems. Selectivity coefficients determined via nonlinear regression enabled quantitative comparisons of different competing ion strength, with the eluting strength increasing in the order of fluoride, acetate, chloride, and sulfate. Optimization of the polymer and eluent concentration was performed for all electrolyte systems using the normalized resolution product optimization criterion, requiring only seven experiments to obtain the optimum conditions for complete separation. The minimum resolution criterion was used to optimize the fluoride system which gave a different separation selectivity from both CE and IC. C1 Univ Tasmania, Sch Chem, Hobart, Tas 7001, Australia. Iowa State Univ, Dept Chem, Ames, IA USA. Iowa State Univ, Ames Lab, Ames, IA USA. RP Haddad, PR (reprint author), Univ Tasmania, Sch Chem, GPO Box 252-75, Hobart, Tas 7001, Australia. NR 22 TC 18 Z9 18 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD SEP PY 2000 VL 21 IS 15 BP 3181 EP 3190 DI 10.1002/1522-2683(20000901)21:15<3181::AID-ELPS3181>3.0.CO;2-L PG 10 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 354FC UT WOS:000089318300016 PM 11001216 ER PT J AU Wallenborg, SR Lurie, IS Arnold, DW Bailey, CG AF Wallenborg, SR Lurie, IS Arnold, DW Bailey, CG TI On-chip chiral and achiral separation of amphetamine and related compounds labeled with 4-fluoro-7-nitrobenzofurazane SO ELECTROPHORESIS LA English DT Article DE chiral separations; drugs; chip-based analysis ID LASER-INDUCED FLUORESCENCE; CAPILLARY-ELECTROPHORESIS; ENANTIOMERIC SEPARATION; SULFATED CYCLODEXTRINS; POSTCOLUMN REACTOR; FORENSIC INTEREST; HUMAN URINE; METHAMPHETAMINE; PHENETHYLAMINES; CHROMATOGRAPHY AB Amphetamine and analogous compounds have been labeled with 4-fluoro-7-nitrobenzofurazane and analyzed on a microfabricated chip. Separation of norephedrine, ephedrine, cathinone, pseudoephedrine, methcathinone, amphetamine and methamphetamine is demonstrated using micellar electrokinetic capillary chromatography (MEKC) and laser-induced fluorescence (LIF) detection. Chiral separations of individual drugs were studied using neutral and negatively charged cyclodextrins (CDs) with and without the addition of an organic modifier and/or sodium dodecyl sulfate (SDS). The best results were obtained using a highly sulfated gamma-CD (HS-gamma-CD) in combination with a low concentration of SDS. To obtain complete separation of a mixture of (+/-)norephedrine, (+/-)ephedrine, (+/-)-pseudoephedrine, (+/-)-methcathinone, (+/-)amphetamine and (+/-)-methamphetamine it was necessary to add a small amount (1.5 mM) of SDS to the separation buffer. Optimized chiral separation was achieved within 7 min using an S-folded separation channel, a separation voltage of 8 kV and a buffer consisting of 50 mM phosphate (pH 7.35), 10 mM HS-gamma-CD and 1.5 mM SDS. C1 Sandia Natl Labs, Livermore, CA 94551 USA. US Drug Enforcement Adm, Special Testing & Res Lab, Mclean, VA USA. RP Bailey, CG (reprint author), Sandia Natl Labs, POB 969,MS9671, Livermore, CA 94551 USA. OI Lurie, Ira/0000-0003-3844-5120 NR 24 TC 68 Z9 73 U1 1 U2 6 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD SEP PY 2000 VL 21 IS 15 BP 3257 EP 3263 DI 10.1002/1522-2683(20000901)21:15<3257::AID-ELPS3257>3.0.CO;2-M PG 7 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 354FC UT WOS:000089318300024 PM 11001224 ER PT J AU Levinson, R Delp, WW Dickerhoff, D Modera, M AF Levinson, R Delp, WW Dickerhoff, D Modera, M TI Effects of airflow infiltration on the thermal performance of internally insulated ducts SO ENERGY AND BUILDINGS LA English DT Article DE airflow infiltration; thermal performance; internal-duct insulation AB Air flowing through a supply duct infiltrates perviously faced, porous, internal duct insulation, degrading its thermal performance. Encapsulating the insulation's air-facing surface with an impervious barrier prevents infiltration, increasing the capacity of the conditioned supply air to heat or cool the space to which it is delivered. This study determined the air-speed dependence of the thermal conductivity of fiberglass insulation by measuring the inlet-to-outlet temperature drop of heated air flowing through a long, insulated flexible duct. The conductivity of a flexible duct's low-density, internal, fiberglass-blanket insulation increased with the square of the duct air speed, rising by 140% as the duct air speed increased from 0 to 15 m s(-1). At air speeds recommended for branch ducts, the conductivity of such insulation would increase by 6% above its still-air value in a residential system and by 16% in a commercial system. Results partially agreed with those reported by an earlier study. Simulations indicate that encapsulating the air-stream surface of internal fiberglass duct insulation with an impervious barrier increases the effectiveness with which a duct delivers the thermal capacity of supply air by 0.15%-0.9% in typical duct systems. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Levinson, R (reprint author), 2252 Parker St 302, Berkeley, CA 94704 USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7788 J9 ENERG BUILDINGS JI Energy Build. PD SEP PY 2000 VL 32 IS 3 BP 345 EP 354 DI 10.1016/S0378-7788(00)00055-4 PG 10 WC Construction & Building Technology; Energy & Fuels; Engineering, Civil SC Construction & Building Technology; Energy & Fuels; Engineering GA 338WX UT WOS:000088447200012 ER PT J AU Van Aelst, J Yperman, J Franco, DV Van Poucke, LC Buchanan, AC Britt, PF AF Van Aelst, J Yperman, J Franco, DV Van Poucke, LC Buchanan, AC Britt, PF TI Study of silica-immobilized sulfur model compounds as calibrants for the AP-TPR study of oxidized coal samples SO ENERGY & FUELS LA English DT Article ID TEMPERATURE-PROGRAMMED REDUCTION; THIOBACILLUS-FERROOXIDANS; THERMAL-BEHAVIOR; PYROLYSIS; MOLECULES; FORMS; FUELS AB Desulfurization of coal prior to combustion has developed the need for an accurate technique to determine which sulfur groups are present before and after chemical treatment. Atmospheric pressure-temperature programmed reduction (AP-TPR) is a technique that can determine the sulfur distribution by using model compounds as calibrants. This study deals with a series of model compounds for oxidized sulfur functionalities. It is proven by AP-TPR and AP-TPR-MS that the sulfur groups of these model compounds are decomposed and that decomposition products (SO/SO2) are only partially reduced. Diaryl sulfoxides and sulfones are found to be more stable than their aryl alkyl-substituted counterparts, and sulfones are more stable than the structurally related sulfoxides. Sulfates are generally found to be the most stable oxidized forms of sulfur. C1 Limburgs Univ Ctr, IMO, Mat Chem Div, B-3590 Diepenbeek, Belgium. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Yperman, J (reprint author), Limburgs Univ Ctr, IMO, Mat Chem Div, Univ Laan, B-3590 Diepenbeek, Belgium. NR 24 TC 25 Z9 25 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 2000 VL 14 IS 5 BP 1002 EP 1008 DI 10.1021/ef000019n PG 7 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 357DR UT WOS:000089483700008 ER PT J AU Liu, C Stout, MG Asay, BW AF Liu, C Stout, MG Asay, BW TI Stress bridging in a heterogeneous material SO ENGINEERING FRACTURE MECHANICS LA English DT Article DE stress bridging; heterogeneous materials; optical interferometry ID RESISTANCE; CERAMICS AB The fracture process of a material denoted PBS 9501 sugar mock, a simulant of the PBX 9501 high explosive, was studied using the optical technique of Coherent Gradient Sensing (CGS) interferometry. We found that in the PBS 9501 sugar mock material, crack initiation and propagation are preceded by the formation and extension of a sizable stress-bridging zone. Two mechanisms were identified as contributing to the bridging process. One is crystal interlocking and Friction, and the other is binder stretching. By comparing the experimental CGS fringe pattern with one simulated using a simple bridging model, we found that the overall behavior of the bridging zone is hardening, which is consistent with the fact that majority of the bridging region is dominated by a binder stretching mechanism. We conclude that the entire process of stress-bridging initiation and extension, as well as subsequent crack propagation, has to be considered in describing the fracture behavior of high explosive materials. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Dynam Experimentat Div, Los Alamos, NM 87545 USA. RP Liu, C (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MST-8,Mail Stop G755, Los Alamos, NM 87545 USA. NR 19 TC 9 Z9 10 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-7944 J9 ENG FRACT MECH JI Eng. Fract. Mech. PD SEP PY 2000 VL 67 IS 1 BP 1 EP 20 DI 10.1016/S0013-7944(00)00041-2 PG 20 WC Mechanics SC Mechanics GA 343NP UT WOS:000088708700001 ER PT J AU McKone, TE Hammond, SK AF McKone, TE Hammond, SK TI Managing the health impacts of waste incineration SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MUNICIPAL; WORKERS C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Sch Publ Hlth, Berkeley, CA 94720 USA. RP McKone, TE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 10 TC 6 Z9 6 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD SEP 1 PY 2000 VL 34 IS 17 BP 380A EP 387A DI 10.1021/es0033988 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 349RQ UT WOS:000089059700011 PM 21662006 ER PT J AU Kean, AJ Harley, RA Littlejohn, D Kendall, GR AF Kean, AJ Harley, RA Littlejohn, D Kendall, GR TI On-road measurement of ammonia and other motor vehicle exhaust emissions SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ATMOSPHERIC AMMONIA; OXIDE EMISSIONS; DEPOSITION; VERIFICATION; GASOLINE; TUNNELS; AEROSOL; AMINES; IMPACT; SYSTEM AB Ammonia is the primary alkaline gas in the atmosphere and contributes to fine particle mass, visibility problems, acid dry and wet deposition. The objective of this research was to measure ammonia and other exhaust emissions from a large sample of on-road vehicles using California phase 2 reformulated gasoline with low sulfur content (similar to 10 ppm by weight). Vehicle emissions of ammonia, NOx, CO, and CO2 were measured in the center bore of a San Francisco Bay area highway tunnel on eight 2-h afternoon sampling periods during summer 1999. Ammonia concentrations were divided by total carbon (mainly CO2) concentrations to compute an emission factor of 475 +/- 29 mg L-1 (95% C.I.). The molar ratio of nitrogen emitted in the tunnel in the form of ammonia to that emitted in the form of NOx was 0.27 +/- 0.01, Emissions of NOx and CO have been measured at this tunnel sampling location since 1994, From 1994 to 1999, emissions decreased by 41 +/- 4% for N0(x) and 54 +/- 6% for CO. These reductions include the impacts of turnover in the vehicle fleet and the use of reformulated gasoline. Between 1997 and 1999, when fuel properties did not change significantly, emissions of NO, and CO decreased by 26 +/- 2% and 31 +/- 3%, respectively. While use of three-way catalytic converters has contributed to decreases in NO, and CO emissions, their use, in combination with fuel-rich engine operation, is the likely cause of the ammonia emissions from motor vehicles observed during this study. C1 Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Bay Area Air Qual Management Dist, Tech Serv Div, San Francisco, CA 94109 USA. RP Harley, RA (reprint author), Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. RI Harley, Robert/C-9177-2016 OI Harley, Robert/0000-0002-0559-1917 NR 32 TC 87 Z9 88 U1 3 U2 25 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 2000 VL 34 IS 17 BP 3535 EP 3539 DI 10.1021/es991451q PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 349RQ UT WOS:000089059700014 ER PT J AU Brusseau, ML Nelson, NT Oostrom, M Zhang, ZH Johnson, GR Wietsma, TW AF Brusseau, ML Nelson, NT Oostrom, M Zhang, ZH Johnson, GR Wietsma, TW TI Influence of heterogeneity and sampling method on aqueous concentrations associated with NAPL dissolution SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MASS-TRANSFER CHARACTERISTICS; DENSE CHLORINATED SOLVENTS; POROUS-MEDIA; POOL DISSOLUTION; LIQUID; TRANSPORT; MODEL; FLOW AB The purpose of this work is to examine the effects of nonuniform distributions of nonaqueous-phase liquid (NAPL) saturation, porous-media heterogeneity, and sampling method on the magnitude of aqueous concentrations measured under dynamic conditions of flow and transport. Dissolution experiments were conducted in an intermediate-scale flow cell packed with sand in which two zones of residual trichloroethene (TCE) saturation were placed. One was created in the same medium-grained sand as used for the flow cell matrix (zone 2), and the other was created in finer sand (zone 1), Aqueous samples were collected using depth-specific sampling ports, vertically integrated sampling ports, and at the fully screened extraction well. A dual-energy gamma-radiation system was used to measure TCE saturation before and after the experiment. The results indicate that mass removal occurred relatively uniformly across the upgradient edge of zone 2 and continued progressively along the longitudinal axis of the zone throughout the course of flushing. Conversely, mass removal was confined primarily to the perimeter of zone 1. The magnitude of the aqueous-phase TCE concentrations varied as a function of location and sampling method. The concentrations measured at the point-sampling ports downgradient of zone 2 were close to the value of aqueous solubility. Conversely, the concentrations measured at the point-sampling ports downgradient of zone 1 were about one-fourth of solubility. The TCE concentrations measured at the vertically integrated ports and at the extraction well were significantly less than the concentrations measured at the point-sampling ports. Given that substantial TCE saturation remained at the end of the experiment, the less than solubility concentrations observed for zone 1 and for the extraction well appear to reflect in part a steady-state dynamic equilibrium with the physical heterogeneity-induced nonuniform flow field. The less than solubility concentrations, especially for the integrated ports and the extraction well, were also influenced significantly by sampling-associated dilution related to the nonuniform NAPL distribution. These observations are supported by the results of a nonreactive tracer test, by the results of a dye-tracer test, and by a quantitative analysis of flow and tracer transport obtained using a three-dimensional mathematical model. C1 Univ Arizona, Dept Soil Water & Environm Sci, Tucson, AZ 85721 USA. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. Pacific NW Natl Lab, Environm Technol Div, Richland, WA 99352 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Brusseau, ML (reprint author), Univ Arizona, Dept Soil Water & Environm Sci, Shantz Bldg,Room 429, Tucson, AZ 85721 USA. EM brusseau@ag.arizona.edu NR 19 TC 35 Z9 35 U1 3 U2 8 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 2000 VL 34 IS 17 BP 3657 EP 3664 DI 10.1021/es9909677 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 349RQ UT WOS:000089059700031 ER PT J AU O'Day, PA Carroll, SA Randall, S Martinelli, RE Anderson, SL Jelinski, J Knezovich, JP AF O'Day, PA Carroll, SA Randall, S Martinelli, RE Anderson, SL Jelinski, J Knezovich, JP TI Metal speciation and bioavailability in contaminated estuary sediments, Alameda Naval Air Station, California SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ACID-VOLATILE SULFIDE; MULTIPLE-SCATTERING CALCULATIONS; ABSORPTION FINE-STRUCTURE; TRACE-METALS; TOXICITY; CADMIUM; IRON; WATERS; MODEL; AVS AB Measurements of simultaneously extracted metals (SEM), acid volatile sulfide (AVS), and invertebrate toxicity were combined with X-ray absorption spectroscopy (XAS) to evaluate metal speciation and ecological hazard of contaminated sediments from the Seaplane Lagoon, Naval Air Station Alameda (CA). This site is characterized by moderate to low toxicity in surface sediments and by metal concentrations in sediments and porewaters that increase with depth. Standard l-h Sigma SEM/AVS measurements for surface sediments were compared with time-series (0.25-24 h) measurements of metal and sulfide release from sediments at 30 cm. Results show that AVS is rapidly and completely evolved after 1 h, but metal extraction continues with time and is not complete after 24 h. Sediment-water interface tests of invertebrate toxicity using sand dollar embryos (D. excentricus) and adult amphipods (E. estuarius) exposed to intact cores showed no to low toxicity in surface sediments. In sediments from 30- and 60-cm depth, high toxicity in several replicates was attributed to factors other than metal concentrations, such as high dissolved ammonia or low dissolved oxygen concentrations. Metal speciation and bonding determined from XAS show that cadmium (100%), zinc (approximate to 80%), and manganese (approximate to 50-70%) are associated with monosulfide phases in the sediments, The remaining fraction of zinc and manganese and all of the chromium and lead are ligated by oxygen atoms, indicating association with oxide, carbonate, or silicate minerals. Iron is present in the sediments in two fractions, as Fe(ll) in the sulfide phase pyrite and as oxygen-ligated octahedral iron, probably associated with clay minerals. Bulk chemical measurements of porewaters and sediments, and speciation information from XAS, suggest that AVS could be accounted for by volatilization of porewater sulfide. Our results indicate that metals are removed from porewaters by formation of monosulfide phases only for cadmium and partially for zinc and manganese but not for lead or chromium, even though these are reduced, anoxic sediments typical of a restricted marine estuary environment. Comparison of geochemical, spectroscopic, and biological data provides new insight for the interpretation of Sigma SEM/AVS measurements and points out the need for synergistic biological/geochemical tests for determining potential ecological hazard. C1 Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA. Univ Calif Lawrence Livermore Natl Lab, Earth & Environm Sci Directorate, Livermore, CA 94550 USA. Univ Bristol, Dept Earth Sci, Bristol BS8 1RJ, Avon, England. Lawrence Berkeley Natl Lab, Div Energy & Environm, Berkeley, CA 94720 USA. Univ Calif Davis, Bodega Marine Lab, Bodega Bay, CA 94923 USA. RP O'Day, PA (reprint author), Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA. NR 32 TC 70 Z9 74 U1 2 U2 18 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 2000 VL 34 IS 17 BP 3665 EP 3673 DI 10.1021/es9913030 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 349RQ UT WOS:000089059700032 ER PT J AU Seaman, JC Bertsch, PM AF Seaman, JC Bertsch, PM TI Selective colloid mobilization through surface-charge manipulation SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID POROUS-MEDIA; ELECTROLYTE CONCENTRATION; HYDRAULIC CONDUCTIVITY; FACILITATED TRANSPORT; IRON-OXIDES; CONTAMINANT TRANSPORT; CLAY DISPERSION; MOBILE COLLOIDS; FLOW CONDITIONS; IONIC-STRENGTH AB The objective of the current study was to evaluate the use of amine hexadecyltrimethylammonium bromide (HDTMA) to enhance the mobilization and subsequent transport of colloidal iron oxides by selectively blocking negatively charged sites within soil or aquifer sediments. Two materials were used in a series of column leaching studies, a surface soil (Orangeburg Series) and an iron oxide-rich subsurface sediment (Tobacco Rd. Formation) both from Aiken, SC. For comparison, the same materials were leached with sodium hexametaphosphate (Na-P) as a nonselective dispersing agent. As a cationic surfactant HDTMA is generally considered a strong flocculent for soils because of its ability to shield the electrostatic repulsion on opposing negatively charged clays, which was observed in leaching experiments for the surface soil material. Leaching HDTMA solutions through the iron oxide-coated aquifer sediments resulted in the selective dispersion and transport of iron oxides, relative to the more abundant kaolinite. Despite effluent colloid levels in excess of 6 g L-1, no column plugging was observed for the HDTMA treatments. The Na-P treatment, however, produced effluent turbidity levels that were less than HDTMA but induced rapid column plugging. Thermal characterization of the Na-P-derived colloids indicated that they were similar to the same as the bulk clay fraction of the aquifer sediment, indicating that dispersion was nonselective. HDTMA appears to block negatively charged filtration sites that limit iron oxide transport, thus enhancing colloid dispersion without inducing column plugging observed for nonselective dispersants. Iron oxides have been demonstrated to be the resident phase for many inorganic and organic contaminants within highly weathered, organic matter-poor systems. This suggests that selective mobilization of colloidal iron oxides and their associated contaminants can potentially enhance subsurface remediation activities via implementation of pump-and-treat technologies. C1 Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29802 USA. RP Seaman, JC (reprint author), Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Drawer E, Aiken, SC 29802 USA. NR 55 TC 15 Z9 15 U1 3 U2 15 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 2000 VL 34 IS 17 BP 3749 EP 3755 DI 10.1021/es001056w PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 349RQ UT WOS:000089059700044 ER PT J AU Bonnesen, PV Brown, GM Alexandratos, SD Bavoux, LB Presley, DJ Patel, V Ober, R Moyer, BA AF Bonnesen, PV Brown, GM Alexandratos, SD Bavoux, LB Presley, DJ Patel, V Ober, R Moyer, BA TI Development of bifunctional anion-exchange resins with improved selectivity and sorptive kinetics for pertechnetate: Batch-equilibrium experiments SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CONTAMINATED GROUNDWATER; TC-99; REMOVAL AB A novel class of strong-base anion-exchange resins, bearing two different types of exchange sites, is described. These bifunctional resins have anion-exchange sites composed of two separate and differently sized trialkylammonium groups. In pertechnetate (TcO4-) uptake experiments from a solution matrix containing anions commonly encountered in groundwater, bifunctional resins containing exchange sites derived from tri-n-hexylamine in combination with either triethylamine, tri-n-propylamine, or tri-n-butylamine were shown to possess superior 24-h distribution ratios (K-d) for pertechnetate over all monofunctional anion-exchange resins (derived from a single trialkylamine) examined. For example, although monofunctional resins containing a tri-n-hexylammonium exchange site possessed excellent selectivity for pertechnetate over other anions, the exchange kinetics were poor. The superior performance of these resins can be attributed to the combination of a large trialkylammonium site for enhanced selectivity for large anions and a smaller trialkylammonium site for the retention of good exchange kinetics. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RP Brown, GM (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Solominow, Sonia/A-4021-2008; Bonnesen, Peter/A-1889-2016; Moyer, Bruce/L-2744-2016 OI Bonnesen, Peter/0000-0002-1397-8281; Moyer, Bruce/0000-0001-7484-6277 NR 20 TC 60 Z9 61 U1 1 U2 17 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 2000 VL 34 IS 17 BP 3761 EP 3766 DI 10.1021/es990858s PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 349RQ UT WOS:000089059700046 ER PT J AU O'Loughlin, EJ Traina, SJ Sims, GK AF O'Loughlin, EJ Traina, SJ Sims, GK TI Effects of sorption on the biodegradation of 2-methylpyridine in aqueous suspensions of reference clay minerals SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE biodegradation; bioavailability; sorption; 2-methylpyridine; clay minerals ID NITROGEN HETEROCYCLIC-COMPOUNDS; SUBSURFACE MATERIALS; QUINOLINE SORPTION; ORGANIC SOLUTES; SOIL; DEGRADATION; MICROORGANISMS; WATER; 2-HYDROXYPYRIDINE; MONTMORILLONITE AB The effects of sorption on the bioavailability of 2-methylpyridine (2-MP) were investigated by determining the biodegradation of 2-MP by an Arthrobacter sp. in aqueous suspensions of reference clay minerals and a synthetic cation exchange resin. Adsorption of 2-MP on kaolinite, illite, hectorite, montmorillonite, and Dowex(R) was determined by the batch equilibrium method. In general, adsorption of 2-MP was positively correlated with the cation exchange capacity of the sorbent, suggesting that sorption of 2-MP on clay minerals occurs through a cation exchange reaction via the 2-methylpyridinium ion. The biodegradation of 2-MP was most rapid in the kaolinite suspensions, followed by no clay > illite much greater than Dowex > hectorite/montmorillonite. With the exception of kaolinite, adsorption of 2-MP on clay minerals and Dowex reduced the rate of biodegradation. The degree of attenuation was positively correlated with the fraction of 2-MP sorbed, suggesting that sorbed 2-MP was not directly available for degradation. Desorption was not rate limiting in suspensions containing hectorite, montmorillonite, or Dowex; however, desorption may have become limiting in the kaolinite and illite suspensions. The results of this study clearly indicate that adsorption can directly affect the degradation of 2-MP in complex mineral systems. C1 Ohio State Univ, Sch Nat Resources, Columbus, OH 43210 USA. Univ Illinois, USDA, Agr Res Serv, Fukuoka 81801, Japan. RP O'Loughlin, EJ (reprint author), Argonne Natl Lab, Div Environm Res, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Sims, Gerald/A-2500-2008; O'Loughlin, Edward/C-9565-2013 OI O'Loughlin, Edward/0000-0003-1607-9529 NR 34 TC 10 Z9 13 U1 1 U2 3 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 SEP PY 2000 VL 19 IS 9 BP 2168 EP 2174 DI 10.1897/1551-5028(2000)019<2168:EOSOTB>2.3.CO;2 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 373BP UT WOS:000165268800004 ER PT J AU Blower, PJ Kettle, AG O'Doherty, MJ Coakley, AJ Knapp, FF AF Blower, PJ Kettle, AG O'Doherty, MJ Coakley, AJ Knapp, FF TI Tc-99m(V)DMSA quantitatively predicts Re-188(V)DMSA distribution in patients with prostate cancer metastatic to bone SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE rhenium-188; dimercaptosuccinic acid; prostate cancer; bone metastases; therapy ID RADIOTHERAPEUTIC AGENT; ACID AB Rhenium-188 dimercaptosuccinic acid complex [Re-188(V)DMSA], a potential therapeutic analogue of the tumour imaging agent Tc-99m(V)DMSA, is selectively taken up in bone metastases in patients with prostate cancer. It would be helpful in planning palliative radionuclide therapy if Tc-99m(V)DMSA could be used to predict tumour and kidney retention of Re-188(V)DMSA, The aim of this study was to determine the correlation between tumour-to-normal tissue ratios and kidney-to-soft tissue ratios of Tc-99m(V)DMSA and Re-188(V)DMSA. This would determine whether a scan with Tc-99m(V) DMSA could be used to identify patients for whom Re-188(V)DMSA treatment would be contra-indicated, and enable prediction of relative kidney and tumour radiation absorbed dose in Re-188(V)DMSA treatment. Ten patients with prostate carcinoma were recruited following observation of disseminated bone metastases on a recent Tc-99m-hydroxydiphosphonate bone scan. Whole-body planar scans were obtained at ca, 4 h and 24 h after hydration and injection of 600 MBq Tc-99m(V)DMSA, and a week later, at similar times after hydration and injection of 370 MBq Re-188(V)DMSA, A triple-energy window (TEW) scatter correction was applied to the Re-188 scans. Counts per pixel were determined in regions of interest drawn over metastatic sites, kidneys and normal soft tissue. Tumour-to-soft tissue ratios were significantly lower (by a factor of approximately 0.8 after the TEW was applied) on Re-188 scans than on Tc-99m scans, but the two were highly linearly correlated both in all individual patients and in tumours pooled from all patients together both at 4 h and at 24 h. Kidney-to-soft tissue ratios were similarly correlated and were lower for Re-188 than for Tc-99m by a similar factor, Both tumour- and kidney-to-soft tissue ratios increased between 4 and 24 h but the latter increased more, In conclusion, only minor differences were seen between Tc-99m and Re-188 scans, and kidney-to-background ratios on Re-188 scans were not higher than on Tc-99m scans. These differences are insufficient to infer that they are due to a real difference in biodistribution, and they may be due only to different physical imaging characteristics. Thus Tc-99m(V)DMSA scans are predictive of Re-188(V)DMSA biodistribution and could be used to estimate tumour and renal dosimetry and assess suitability of patients for Re-188(V)DMSA treatment. C1 Kent & Canterbury Hosp, Dept Nucl Med, Canterbury CT1 3NG, Kent, England. Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN 37831 USA. RP Blower, PJ (reprint author), Kent & Canterbury Hosp, Dept Nucl Med, Canterbury CT1 3NG, Kent, England. NR 11 TC 36 Z9 36 U1 0 U2 4 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 2000 VL 27 IS 9 BP 1405 EP 1409 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 352EN UT WOS:000089201700020 PM 11007525 ER PT J AU Ekman, J Rudolph, D Fahlander, C Charity, RJ Reviol, W Sarantites, DG Tomov, V Clark, RM Cromaz, M Fallon, P Macchiavelli, AO Carpenter, M Seweryniak, D AF Ekman, J Rudolph, D Fahlander, C Charity, RJ Reviol, W Sarantites, DG Tomov, V Clark, RM Cromaz, M Fallon, P Macchiavelli, AO Carpenter, M Seweryniak, D TI The A=51 mirror nuclei Fe-51 and Mn-51 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID HIGH-SPIN STATES; SHELL-MODEL; GAMMASPHERE AB Eighteen previously unknown gamma -ray transitions were identified in the T-z = -1/2 nucleus Fe-51 following the fusion-evaporation reaction S-32(Si-28,2 alpha 1n)Fe-51. The lever scheme reaches the fully aligned I-pi = 27/2(-) terminating state of the five holes in the f(7/2) shell. The 17/2(-) state was found to be isomeric, and the lifetime was measured to be 2.87 ns. The mirror symmetry of Fe-51 and Mn-51 is discussed, and the level scheme of Fe-51 is compared to shell-model calculations. C1 Univ Lund, Dept Phys, S-22100 Lund, Sweden. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Univ Calif Berkeley, Div Nucl Sci, Berkeley, CA 94720 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Ekman, J (reprint author), Univ Lund, Dept Phys, S-22100 Lund, Sweden. RI Rudolph, Dirk/D-4259-2009; Ekman, Jorgen/C-1385-2013; Carpenter, Michael/E-4287-2015; OI Rudolph, Dirk/0000-0003-1199-3055; Carpenter, Michael/0000-0002-3237-5734; Charity, Robert/0000-0003-3020-4998 NR 21 TC 41 Z9 41 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD SEP PY 2000 VL 9 IS 1 BP 13 EP 17 DI 10.1007/s100500070050 PG 5 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 376DU UT WOS:000165443600004 ER PT J AU Aggarwal, MM Agnihotri, A Ahammed, Z Angelis, ALS Antonenko, V Arefiev, V Astakhov, V Avdeitchikov, V Awes, TC Baba, PVKS Badyal, SK Barlag, C Bathe, S Batiounia, B Bernier, T Bhalla, KB Bhatia, VS Blume, C Bock, R Bohne, EM Borocz, Z Bucher, D Buijs, A Busching, H Carlen, L Chalyshev, V Chattopadhyay, S Cherbatchev, R Chujo, T Claussen, A Das, AC Decowski, MP Delagrange, H Djordjadze, V Donni, P Doubovik, I Dutt, S Majumdar, MRD El Chenawi, K Eliseev, S Enosawa, K Foka, P Fokin, S Ganti, MS Garpman, S Gavrishchuk, O Geurts, FJM Ghosh, TK Glasow, R Gupta, SK Guskov, B Gustafsson, HA Gutbrod, HH Higuchi, R Hrivnacova, I Ippolitov, M Kalechofsky, H Kamermans, R Kampert, KH Karadjev, K Karpio, K Kato, S Kees, S Klein-Bosing, C Knoche, S Kolb, BW Kosarev, I Koutcheryaev, I Krumpel, T Kugler, A Kulinich, P Kurata, M Kurita, K Kuzmin, N Langbein, I Lebedev, A Lee, YY Lohner, H Luquin, L Mahapatra, DP Manko, V Martin, M Martinez, G Maximov, A Mgebrichvili, G Miake, Y Mir, MF Mishra, GC Miyamoto, Y Mohanty, B Morrison, D Mukhopadhyay, DS Naef, H Nandi, BK Nayak, SK Nayak, TK Neumaier, S Nianine, A Nikitine, V Nikolaev, S Nilsson, P Nishimura, S Nomokonov, P Nystrand, J Obenshain, FE Oskarsson, A Otterlund, I Pachr, M Pavliouk, S Peitzmann, T Petracek, V Pinganaud, W Plasil, F von Poblotzki, U Purschke, ML Rak, J Raniwala, R Raniwala, S Ramamurthy, VS Rao, NK Retiere, F Reygers, K Roland, G Rosselet, L Roufanov, I Roy, C Rubio, JM Sako, H Sambyal, SS Santo, R Sato, S Schlagheck, H Schmidt, HR Schutz, Y Shabratova, G Shah, TH Sibiriak, I Siemiarczuk, T Silvermyr, D Sinha, BC Slavine, N Soderstrom, K Solomey, N Sorensen, SP Stankus, P Stefanek, G Steinberg, P Stenlund, E Stuken, D Sumbera, M Svensson, T Trivedi, MD Tsvetkov, A Tykarski, L Urbahn, J vander Pijll, EC von Eijndhoven, N von Nieuwenhuizen, GJ Vinogradov, A Viyogi, YP Vodopianov, A Voros, S Wyslouch, B Yagi, K Yokota, Y Young, GR AF Aggarwal, MM Agnihotri, A Ahammed, Z Angelis, ALS Antonenko, V Arefiev, V Astakhov, V Avdeitchikov, V Awes, TC Baba, PVKS Badyal, SK Barlag, C Bathe, S Batiounia, B Bernier, T Bhalla, KB Bhatia, VS Blume, C Bock, R Bohne, EM Borocz, Z Bucher, D Buijs, A Busching, H Carlen, L Chalyshev, V Chattopadhyay, S Cherbatchev, R Chujo, T Claussen, A Das, AC Decowski, MP Delagrange, H Djordjadze, V Donni, P Doubovik, I Dutt, S Majumdar, MRD El Chenawi, K Eliseev, S Enosawa, K Foka, P Fokin, S Ganti, MS Garpman, S Gavrishchuk, O Geurts, FJM Ghosh, TK Glasow, R Gupta, SK Guskov, B Gustafsson, HA Gutbrod, HH Higuchi, R Hrivnacova, I Ippolitov, M Kalechofsky, H Kamermans, R Kampert, KH Karadjev, K Karpio, K Kato, S Kees, S Klein-Bosing, C Knoche, S Kolb, BW Kosarev, I Koutcheryaev, I Krumpel, T Kugler, A Kulinich, P Kurata, M Kurita, K Kuzmin, N Langbein, I Lebedev, A Lee, YY Lohner, H Luquin, L Mahapatra, DP Manko, V Martin, M Martinez, G Maximov, A Mgebrichvili, G Miake, Y Mir, MF Mishra, GC Miyamoto, Y Mohanty, B Morrison, D Mukhopadhyay, DS Naef, H Nandi, BK Nayak, SK Nayak, TK Neumaier, S Nianine, A Nikitine, V Nikolaev, S Nilsson, P Nishimura, S Nomokonov, P Nystrand, J Obenshain, FE Oskarsson, A Otterlund, I Pachr, M Pavliouk, S Peitzmann, T Petracek, V Pinganaud, W Plasil, F von Poblotzki, U Purschke, ML Rak, J Raniwala, R Raniwala, S Ramamurthy, VS Rao, NK Retiere, F Reygers, K Roland, G Rosselet, L Roufanov, I Roy, C Rubio, JM Sako, H Sambyal, SS Santo, R Sato, S Schlagheck, H Schmidt, HR Schutz, Y Shabratova, G Shah, TH Sibiriak, I Siemiarczuk, T Silvermyr, D Sinha, BC Slavine, N Soderstrom, K Solomey, N Sorensen, SP Stankus, P Stefanek, G Steinberg, P Stenlund, E Stuken, D Sumbera, M Svensson, T Trivedi, MD Tsvetkov, A Tykarski, L Urbahn, J vander Pijll, EC von Eijndhoven, N von Nieuwenhuizen, GJ Vinogradov, A Viyogi, YP Vodopianov, A Voros, S Wyslouch, B Yagi, K Yokota, Y Young, GR CA WA98 Collaboration TI Central Pb plus Pb collisions at 158 A GeV/c studied by pi(-)pi(-) interferometry SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID HEAVY-ION COLLISIONS; MULTISTEP AVALANCHE CHAMBERS; PB+PB COLLISIONS; PION INTERFEROMETRY; 2-PION CORRELATIONS; PERFORMANCE; TRACKING; READOUT; SYSTEMS AB Two-particle correlations have been measured for identified pi(-) from central 158 A GeV Pb+Pb collisions and fitted radii of about 7 fm in all dimensions have been obtained. A multi-dimensional study of the radii as a function of k(gamma) is presented, including a full correction for the resolution effects of the apparatus. The cross term R-out-long(2) of the standard fit in the Longitudinally CoMoving System (LCMS) and the upsilon(L) parameter of the generalised Yano-Koonin fit are compatible with 0, suggesting that the source undergoes a boost invariant expansion. The shapes of the correlation functions in Q(inv) and Q(space) = root<(Q(x)(2) + Q(y)(2) + Q(z)(2))over bar> have been analyzed in detail. They are not Gaussian but better represented by exponentials. As a consequence, fitting Gaussians to these correlation functions may produce different radii depending on the acceptance of the experimental setup used for the measurement. C1 Panjab Univ, Chandigarh 160014, India. Univ Rajasthan, Jaipur 302004, Rajasthan, India. Bhabha Atom Res Ctr, Ctr Variable Energy Cyclotron, Kolkata 700064, W Bengal, India. Univ Geneva, CH-1211 Geneva 4, Switzerland. IV Kurchatov Atom Energy Inst, RRC, Moscow 123182, Russia. Joint Inst Nucl Res, Dubna 141980, Russia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Jammu, Jammu 180001, India. Univ Munster, D-48149 Munster, Germany. Ecole Mines, SUBATECH, Nantes, France. Gesell Schwerionenforsch mbH, D-64220 Darmstadt, Germany. Univ Utrecht, NIKHEF, NL-3508 TA Utrecht, Netherlands. Lund Univ, S-22100 Lund, Sweden. Inst Nucl Phys, Rez 25068, Czech Republic. Univ Groningen, KVI, NL-9747 AA Groningen, Netherlands. Inst Nucl Studies, PL-00681 Warsaw, Poland. MIT, Cambridge, MA 02139 USA. Inst Phys, Bhubaneswar 751005, Orissa, India. Univ Tennessee, Knoxville, TN 37996 USA. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. RP Aggarwal, MM (reprint author), Panjab Univ, Chandigarh 160014, India. RI Decowski, Patrick/A-4341-2011; Peitzmann, Thomas/K-2206-2012; Lohner, Herbert/B-2397-2014; Sumbera, Michal/O-7497-2014; OI Peitzmann, Thomas/0000-0002-7116-899X; Lohner, Herbert/0000-0002-7441-739X; Sumbera, Michal/0000-0002-0639-7323; Mohanty, Bedangadas/0000-0001-9610-2914 NR 19 TC 21 Z9 22 U1 1 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1434-6044 EI 1434-6052 J9 EUR PHYS J C JI Eur. Phys. J. C PD SEP PY 2000 VL 16 IS 3 BP 445 EP 451 DI 10.1007/s100520000413 PG 7 WC Physics, Particles & Fields SC Physics GA 353VN UT WOS:000089296300005 ER PT J AU Nie, X Ben-Naim, E Chen, SY AF Nie, X Ben-Naim, E Chen, SY TI Dynamics of vibrated granular monolayers SO EUROPHYSICS LETTERS LA English DT Article ID HYDRODYNAMICS; FLUCTUATIONS; MATTER; SYSTEM; GASES; FLOWS AB We study statistical properties of vibrated granular monolayers using molecular dynamics simulations. We show that at high excitation strengths, the system is in a gas state, particle motion is isotropic, and the velocity distributions are Gaussian. As the vibration strength is lowered, the system's dimensionality is effectively reduced from three to two. Below a critical excitation strength, a cluster phase occurs, and the velocity distribution becomes bimodal. In this phase, the system consists of clusters of immobile particles arranged in close-packed hexagonal arrays, and gas particles whose energy equals the first excited state of an isolated particle on a vibrated plate. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. IBM Corp, Div Res, Thomas J Watson Res Ctr, Yorktown Heights, NY 10598 USA. RP Nie, X (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Ben-Naim, Eli/C-7542-2009; Chen, Shiyi/A-3234-2010 OI Ben-Naim, Eli/0000-0002-2444-7304; NR 16 TC 42 Z9 43 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD SEP PY 2000 VL 51 IS 6 BP 679 EP 684 DI 10.1209/epl/i2000-00392-7 PG 6 WC Physics, Multidisciplinary SC Physics GA 356FD UT WOS:000089432600014 ER PT J AU Pelikan, M Goldberg, DE Cantu-Paz, E AF Pelikan, Martin Goldberg, David E. Cantu-Paz, Erick TI Linkage Problem, Distribution Estimation, and Bayesian Networks SO EVOLUTIONARY COMPUTATION LA English DT Article DE Genetic and evolutionary computation; linkage learning; estimation of distribution algorithm; probabilistic modeling; learning Bayesian networks; genetic algorithm AB This paper proposes an algorithm that uses an estimation of the joint distribution of promising solutions in order to generate new candidate solutions. The algorithm is settled into the context of genetic and evolutionary computation and the algorithms based on the estimation of distributions. The proposed algorithm is called the Bayesian Optimization Algorithm (BOA). To estimate the distribution of promising solutions, the techniques for modeling multivariate data by Bayesian networks are used. The BOA identifies, reproduces, and mixes building blocks up to a specified order. It is independent of the ordering of the variables in strings representing the solutions. Moreover, prior information about the problem can be incorporated into the algorithm, but it is not essential. First experiments were done with additively decomposable problems with both nonoverlapping as well as overlapping building blocks. The proposed algorithm is able to solve all but one of the tested problems in linear or close to linear time with respect to the problem size. Except for the maximal order of interactions to be covered, the algorithm does not use any prior knowledge about the problem. The BOA represents a step toward alleviating the problem of identifying and mixing building blocks correctly to obtain good solutions for problems with very limited domain information. C1 [Pelikan, Martin] Univ Illinois, Dept Comp Sci, Urbana, IL 61801 USA. [Goldberg, David E.] Univ Illinois, Illinois Genet Algorithms Lab, Dept Gen Engn, Urbana, IL 61801 USA. [Cantu-Paz, Erick] Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. [Pelikan, Martin] Comenius Univ, Fac Math & Phys, Inst Comp Sci, Bratislava 84215, Slovakia. [Cantu-Paz, Erick] Univ Illinois, Dept Comp Sci, Urbana, IL 61801 USA. RP Pelikan, M (reprint author), Univ Illinois, Dept Comp Sci, 1304 W Springfield Ave, Urbana, IL 61801 USA. EM pelikan@illigal.ge.uiuc.edu; deg@illigal.ge.uiuc.edu; cantupaz@llnl.gov RI Pelikan, Martin/A-8547-2012 FU Scientific Grant Agency of Slovak Republic [1/4209/97, 1/5229/98]; Air Force Office of Scientific Research, Air Force Materiel Command, USAF [F49620-97-1-0050]; U.S. Army Research Laboratory under the Federated Laboratory [DAAL01-96-2-0003] FX The authors would like to thank Heinz Muhlenbein, David Heckerman, and Ole J. Mengshoel for valuable discussions and useful comments. For help with performing a part of the experiments, the authors would also like to thank Pavel Petrovic. Martin Pelikan was supported by grants number 1/4209/97 and 1/5229/98 of the Scientific Grant Agency of Slovak Republic.; The work was sponsored by the Air Force Office of Scientific Research, Air Force Materiel Command, USAF, under grant number F49620-97-1-0050. Research funding for this project was also provided by a grant from the U.S. Army Research Laboratory under the Federated Laboratory Program, Cooperative Agreement DAAL01-96-2-0003. The U.S. Government is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding any copyright notation thereon. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies and endorsements, either expressed or implied, of the Air Force of Scientific Research or the U.S. Government. NR 35 TC 117 Z9 128 U1 0 U2 10 PU MIT PRESS PI CAMBRIDGE PA 55 HAYWARD STREET, CAMBRIDGE, MA 02142 USA SN 1063-6560 J9 EVOL COMPUT JI Evol. Comput. PD FAL PY 2000 VL 8 IS 3 BP 311 EP 340 DI 10.1162/106365600750078808 PG 30 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA V20BE UT WOS:000208114700004 PM 11001554 ER PT J AU Schrems, KK Kassner, ME Kennedy, TC AF Schrems, KK Kassner, ME Kennedy, TC TI Theoretical, experimental and computational mechanics of fracture in constrained interlayers SO EXPERIMENTAL MECHANICS LA English DT Article DE ductile fracture; instability; triaxial stress ID HIGH-TRIAXIAL STRESS; DUCTILE FRACTURE; CAVITATION INSTABILITIES; PLASTIC SOLIDS; SILVER AB The constraint of a thin silver interlayer is used to create high triaxial stresses to evaluate the applicability of theoretical models for ductile fracture. Rice and Tracey's model for cavity expansion under high triaxial states of stress and Huang et al.'s model for cavity instability were considered. The experimentally determined sigma(m)/sigma(y) values suggest that further investigation of the Huang et al. theory is warranted. Microstructural analysis revealed that multiple cavities were initially present in the silver interlayers, and the number and size of the cavities increased as failure was approached. Finite element analysis and experimental results showed excellent agreement in a computational determination of cavity instability. Thus, it appears that ductile fracture in constrained thin interlayers can be explained with unstable cavity growth. C1 US DOE, Albany Res Ctr, Albany, OR 97321 USA. Oregon State Univ, Dept Mech Engn, Corvallis, OR 97331 USA. RP Schrems, KK (reprint author), US DOE, Albany Res Ctr, Albany, OR 97321 USA. NR 10 TC 1 Z9 1 U1 1 U2 1 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD SEP PY 2000 VL 40 IS 3 BP 307 EP 311 DI 10.1007/BF02327504 PG 5 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA 346UG UT WOS:000088889000010 ER PT J AU Greene, GA Finfrock, CC Irvine, TF AF Greene, GA Finfrock, CC Irvine, TF TI Total hemispherical emissivity of oxidized Inconel 718 in the temperature range 300-1000 degrees C SO EXPERIMENTAL THERMAL AND FLUID SCIENCE LA English DT Article AB Total hemispherical emissivities were measured for Inconel 718 as a function of sample temperature. Measurements were made for both unoxidized and oxidized samples. The oxidation temperatures were 1000 degrees C, 1100 degrees C and 1142 degrees C and the oxidation times were 15, 30 and 60 min, respectively. The oxidized samples showed a significant increase in emissivity over the unoxidized one which was in an as-received condition. No apparent pattern was observed in the change of emissivity as a function of oxidation time at a given oxidation temperature. In some cases, emissivity measurements made with increasing temperature were greater than those made with descending temperature. One possible explanation for this is the spalling of the oxide layer as the sample area contracted with descending sample temperature. (C) 2000 Elsevier Science Inc. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. RP Greene, GA (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 10 TC 31 Z9 31 U1 1 U2 10 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0894-1777 J9 EXP THERM FLUID SCI JI Exp. Therm. Fluid Sci. PD SEP PY 2000 VL 22 IS 3-4 BP 145 EP 153 DI 10.1016/S0894-1777(00)00021-2 PG 9 WC Thermodynamics; Engineering, Mechanical; Physics, Fluids & Plasmas SC Thermodynamics; Engineering; Physics GA 362PB UT WOS:000089785400004 ER PT J AU Zlatanova, J Caiafa, P Van Holde, K AF Zlatanova, J Caiafa, P Van Holde, K TI Linker histone binding and displacement: versatile mechanism for transcriptional regulation SO FASEB JOURNAL LA English DT Review DE DNA methylation; linker histone modifications; nucleosomal DNA; transcription regulation ID NUCLEOSOME CORE PARTICLE; RIBOSOMAL-RNA GENE; DNA-METHYLATION; IN-VITRO; CHROMATIN STRUCTURE; H1E HISTONE; PROTHYMOSIN-ALPHA; CPG SEQUENCES; RICH DNA; VARIANT AB In recent years, the connection between chromatin structure and its transcriptional activity has attracted considerable experimental effort. The post-translational modifications to both the core histones and the linker histones are finely tuned through interactions with transcriptional regulators and change chromatin structure in a way to allow transcription to occur. Here we review evidence for the involvement of linker histones in transcriptional regulation and suggest a scenario in which the reversible and controllable binding/displacement of proteins of this class to the nucleosome entry/exit point determine the accessibility of the nucleosomal DNA to the transcriptional machinery. C1 Argonne Natl Lab, Biochip Technol Ctr, Argonne, IL 60439 USA. Univ Rome La Sapienza, Dept Cellular Biotechnol & Hematol, I-00161 Rome, Italy. Oregon State Univ, Dept Biochem & Biophys, Corvallis, OR 97331 USA. RP Zlatanova, J (reprint author), Argonne Natl Lab, Biochip Technol Ctr, 9700 S Cass Ave,Bldg 202-A253, Argonne, IL 60439 USA. RI Zlatanova, Jordanka/B-3273-2009 FU FIC NIH HHS [TW00568] NR 82 TC 115 Z9 125 U1 0 U2 3 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD SEP PY 2000 VL 14 IS 12 BP 1697 EP 1704 DI 10.1096/fj.99-0869rev PG 8 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 352JU UT WOS:000089212400008 PM 10973918 ER PT J AU Jardin, SC Bathke, CG Ehst, DA Kaye, SM Kessel, CE Lee, BJ Mau, TK Menard, J Miller, R Najmabadi, F AF Jardin, SC Bathke, CG Ehst, DA Kaye, SM Kessel, CE Lee, BJ Mau, TK Menard, J Miller, R Najmabadi, F TI Physics basis for a tokamak fusion power plant SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting and Workshop on Fusion Power Plant Design and Technology CY MAR 24-27, 1998 CL UKAEA FUS, CULHAM SCI CTR, HARWELL, ENGLAND SP Int Atom Energy Agcy HO UKAEA FUS, CULHAM SCI CTR DE fusion power plant; tokamak; physics ID ENHANCED CONFINEMENT REGIMES; ASPECT-RATIO TOKAMAKS; CURRENT DRIVE; DIII-D; BOOTSTRAP-CURRENT; HELIUM TRANSPORT; MAGNETIC SHEAR; EXHAUST; STABILITY; PLASMA AB The five ARIES designs, which correspond to five different tokamak operating modes, are reviewed and compared. Physics figures of merit are introduced that quantify the major parameters of a tokamak design in a physics operating space. The five operating modes are compared to one another and to the existing tokamak data base in terms of these physics parameters. While the steady-state first stability design [ARIES-I] and the pulsed first stability design [PULSAR] are closest, no design has yet been completely prototyped in existing tokamaks. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Korean Basix Sci Inst, Taedok, South Korea. Univ Calif San Diego, La Jolla, CA 92093 USA. RP Jardin, SC (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Jardin, Stephen/E-9392-2010; OI Menard, Jonathan/0000-0003-1292-3286 NR 51 TC 12 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD SEP PY 2000 VL 48 IS 3-4 BP 281 EP 298 DI 10.1016/S0920-3796(00)00166-6 PG 18 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 428KL UT WOS:000168460800006 ER PT J AU Cheng, ET Cerbone, RJ Sviatoslavsky, IN Galambos, LD Peng, YKM AF Cheng, ET Cerbone, RJ Sviatoslavsky, IN Galambos, LD Peng, YKM TI Study of a spherical torus based volumetric neutron source for nuclear technology testing and development SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting and Workshop on Fusion Power Plant Design and Technology CY MAR 24-27, 1998 CL UKAEA FUS, CULHAM SCI CTR, HARWELL, ENGLAND SP Int Atom Energy Agcy HO UKAEA FUS, CULHAM SCI CTR DE spherical torus; volumetric neutron source; neutron wall loading AB A plasma based, deuterium and tritium (DT) fueled, volumetric 14 MeV neutron source (VNS) has been considered as a possible facility to support the development of the demonstration fusion power reactor (DEMO). It can be used to test and develop necessary fusion blanket and divertor components and provide sufficient database, particularly on the reliability of nuclear components necessary for DEMO. The VNS device can be complement to ITER by reducing the cost and risk in the development of DEMO. A low cost, scientifically attractive, and technologically feasible volumetric neutron source based on the spherical torus (ST) concept has been conceived. The ST-VNS, which has a major radius of 1.07 m, aspect ratio 1.4, and plasma elongation three, can produce a neutron wall loading from 0.5 to 5 MW m (2) at the outboard test section with a modest fusion power level from 38 to 380 MW. It can be used to test necessary nuclear technologies for fusion power reactor and develop fusion core components include divertor, first wall, and power blanket. Using staged operation leading to high neutron wall loading and optimistic availability, a neutron fluence of more than 30 MW year m(-2) is obtainable within 20 years of operation. This will permit the assessments of lifetime and reliability of promising fusion core components in a reactor relevant environment. A full scale demonstration of power reactor fusion core components is also made possible because of the high neutron wall loading capability. Tritium breeding in such a full scale demonstration can be very useful to ensure the self-sufficiency of fuel cycle for a candidate power blanket concept. (C) 2000 Elsevier Science S.A. All rights reserved. C1 TSI Res Inc, Solana Beach, CA 92075 USA. Univ Wisconsin, Madison, WI USA. Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RP Cheng, ET (reprint author), TSI Res Inc, 225 Stevens Ave, Solana Beach, CA 92075 USA. NR 7 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD SEP PY 2000 VL 48 IS 3-4 BP 299 EP 306 DI 10.1016/S0920-3796(00)00165-4 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 428KL UT WOS:000168460800007 ER PT J AU Sze, DK Tillack, M El-Guebaly, L AF Sze, DK Tillack, M El-Guebaly, L TI Blanket system selection for the ARIES-ST SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting and Workshop on Fusion Power Plant Design and Technology CY MAR 24-27, 1998 CL UKAEA FUS, CULHAM SCI CTR, HARWELL, ENGLAND SP Int Atom Energy Agcy HO UKAEA FUS, CULHAM SCI CTR DE blanket system; conductor; dual coolant AB The ARIES-ST (Spherical Tokamak) is to investigate the attractiveness of a low-aspect-device as the confinement concept for a fusion power plant. The key driven force of the ST design is caused by the center column conductor. The design selected is a water-cooled Cu normal conductor. This selection has a major impact on the blanket design and selection, tritium breeding and over-all power balance. The blanket selected is a dual coolant concept, partially decided by the characteristics of the center conductor. The final blanket design is modified from the dual coolant concept, which developed under the EC DEMO program. The reason for this selection and the design issues are summarized in this paper. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Calif San Diego, San Diego, CA 92103 USA. Univ Wisconsin, Madison, WI USA. ARIES Team, Madison, WI USA. RP Sze, DK (reprint author), Argonne Natl Lab, 9700 S Cass Ave,Bldg 207, Argonne, IL 60439 USA. NR 7 TC 36 Z9 36 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD SEP PY 2000 VL 48 IS 3-4 BP 371 EP 378 DI 10.1016/S0920-3796(00)00146-0 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 428KL UT WOS:000168460800013 ER PT J AU Smith, JS Tachibana, I Lee, HK Qian, JQ Pohl, U Mohrenweiser, HW Borell, TJ Hosek, SM Soderberg, CL von Deimling, A Perry, A Scheithauer, BW Louis, DN Jenkins, RB AF Smith, JS Tachibana, I Lee, HK Qian, JQ Pohl, U Mohrenweiser, HW Borell, TJ Hosek, SM Soderberg, CL von Deimling, A Perry, A Scheithauer, BW Louis, DN Jenkins, RB TI Mapping of the chromosome 19 q-arm glioma tumor suppressor gene using fluorescence in situ hybridization and novel microsatellite markers SO GENES CHROMOSOMES & CANCER LA English DT Article ID BRAIN-TUMORS; OLIGODENDROGLIAL TUMORS; SV40-TRANSFORMED CELLS; CYTOGENETIC ANALYSIS; HUMAN ASTROCYTOMAS; GENOMIC STRUCTURE; CANDIDATE REGION; PHOSPHATASE GENE; PROSTATE-CANCER; ALLELIC LOSS AB Allelic loss of chromosome arm 19q is a frequent event in human diffuse glioma, suggesting the presence of a tumor suppressor gene. Previous loss of heterozygosity (LOH) analyses have mapped this gene to a 1.4-megabase interval, between the genetic markers D19S412 and STD. Further narrowing of this interval has been limited by the resolution of mapped polymorphic markers. In the present study, we have used genomic clones mapped to 19q as fluorescence in situ hybridization (FISH) probes to map the breakpoints of 13 gliomas with 19q13.3 deletion boundaries. In addition, we have developed three new polymorphic microsatellite markers (D19S1180, D19S1181, and D19S1182) that map between D19S412 and STD and have used these new markers to identify two gliomas with small deletions between the D19S412 and STD markers. Collectively, these data suggest that the region of common deletion may be as narrow as 150 kb and should facilitate future efforts to identify the glioma 19q tumor suppressor gene. Genes Chromosomes Cancer 29:16-25, 2000. (C) 2000 Wiley-Liss, Inc. C1 Mayo Clin & Mayo Fdn, Dept Lab Med & Pathol, Div Lab Genet, Rochester, MN 55905 USA. Mayo Clin & Mayo Fdn, Dept Lab Med & Pathol, Div Anat Pathol, Rochester, MN 55905 USA. Massachusetts Gen Hosp, Dept Pathol Neuropathol, Mol Neurooncol Lab, Charlestown, MA USA. Massachusetts Gen Hosp, Neurosurg Serv, Charlestown, MA USA. Harvard Med Sch, Charlestown, MA USA. Lawrence Livermore Natl Lab, Ctr Human Genome, Livermore, CA USA. Univ Hosp, Dept Neuropathol, Bonn, Germany. Washington Univ, Sch Med, Div Neuropathol, St Louis, MO USA. RP Jenkins, RB (reprint author), Mayo Clin, Dept Cytogenet, 200 1st St SW, Rochester, MN 55905 USA. EM rjenkins@mayo.edu RI imoto, Issei/D-8065-2012; von Deimling, Andreas/F-7774-2013; OI von Deimling, Andreas/0000-0002-5863-540X; Perry, Arie/0000-0002-8300-7261 FU NCI NIH HHS [CA50905, CA57683, CA69285] NR 55 TC 64 Z9 65 U1 1 U2 2 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1045-2257 J9 GENE CHROMOSOME CANC JI Gene Chromosomes Cancer PD SEP PY 2000 VL 29 IS 1 BP 16 EP 25 DI 10.1002/1098-2264(2000)9999:9999<::AID-GCC1007>3.3.CO;2-9 PG 10 WC Oncology; Genetics & Heredity SC Oncology; Genetics & Heredity GA 342KQ UT WOS:000088644100003 PM 10918389 ER PT J AU Lersch, RA Fung, J Munne, S Pedersen, RA Weier, HUG AF Lersch, RA Fung, J Munne, S Pedersen, RA Weier, HUG TI Case-specific, breakpoint-spanning DNA probes for analysis of single interphase cells SO GENETIC TESTING LA English DT Article ID IN-SITU HYBRIDIZATION; INSITU HYBRIDIZATION; HUMAN SPERM; ANEUPLOIDIES; DIAGNOSIS; EMBRYOS; FISH AB Balanced reciprocal translocations are known to interfere with homolog pairing in meiosis, Many individuals carrying such chromosomal abnormalities suffer from reduced fertility or spontaneous abortions and seek help in the form of assisted reproductive technology. Although most translocations are relatively easy to detect in metaphase cells, the majority of embryonic cells biopsied in the course of in vitro fertilization (IVF) procedures are in interphase. These nuclei are, thus, unsuitable for analysis by chromosome banding or painting using fluorescence in situ hybridization (FISH), Our assay, based on FISH detection of breakpoint-spanning DNA probes, identifies translocations in interphase nuclei by microscopic inspection of hybridization domains, Probes are selected that span the breakpoint regions on normal homologs, The probes should hybridize to several hundred kilobases of DNA flanking the breakpoint. The two breakpoint-spanning DNA probes for the translocation chromosomes are labeled in separate colors (e.g., red and green). The translocation event producing two fused red/green hybridization domains can then be detected in interphase cell nuclei using a fluorescence microscope. We applied this scheme to analyze somatic and germ cells from 21 translocation patients, each with distinct breakpoints. Here, we summarize our experience and provide a description of strategies, cost estimates, as well as typical time frames. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif San Francisco, Sch Med, Dept Obstet Gynecol & Reprod Sci, Reprod Genet Unit, San Francisco, CA 94143 USA. St Barnabas Med Ctr, Inst Assisted Reprod & Med, W Orange, NJ 07052 USA. RP Weier, HUG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, MS 74-157,1 Cyclotron Rd, Berkeley, CA 94720 USA. OI Munne, Santiago/0000-0002-1088-5565 FU NIEHS NIH HHS [5-T32-ES07106-17] NR 22 TC 4 Z9 4 U1 0 U2 1 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1090-6576 J9 GENET TEST JI Genet. Test. PD FAL PY 2000 VL 4 IS 3 BP 273 EP 278 DI 10.1089/10906570050501498 PG 6 WC Genetics & Heredity; Medicine, Research & Experimental SC Genetics & Heredity; Research & Experimental Medicine GA 380CB UT WOS:000165679800007 PM 11142758 ER PT J AU Dubchak, I Brudno, M Loots, GG Pachter, L Mayor, C Rubin, EM Frazer, KA AF Dubchak, I Brudno, M Loots, GG Pachter, L Mayor, C Rubin, EM Frazer, KA TI Active conservation of noncoding sequences revealed by three-way species comparisons SO GENOME RESEARCH LA English DT Article AB Human and mouse genomic sequence comparisons are being increasingly used to search for evolutionarily conserved gene regulatory elements. Large-scale human-mouse DNA comparison studies have discovered numerous conserved noncoding sequences of which only a fraction has been functionally investigated A question therefore remains as to whether most of these noncoding sequences are conserved because of functional constraints or are the result of a lack of divergence time. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Genome Sci Dept, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Ctr Bioinformat & Computat Genom, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. RP Frazer, KA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Genome Sci Dept, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM-5748202] NR 8 TC 242 Z9 246 U1 0 U2 2 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 USA SN 1088-9051 J9 GENOME RES JI Genome Res. PD SEP PY 2000 VL 10 IS 9 BP 1304 EP 1306 DI 10.1101/gr.142200 PG 3 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 353BY UT WOS:000089254900005 PM 10984448 ER PT J AU Puttagunta, R Gordon, LA Meyer, GE Kapfhamer, D Lamerdin, JE Kantheti, P Portman, KM Chung, WK Jenne, DE Olsen, AS Burmeister, M AF Puttagunta, R Gordon, LA Meyer, GE Kapfhamer, D Lamerdin, JE Kantheti, P Portman, KM Chung, WK Jenne, DE Olsen, AS Burmeister, M TI Comparative maps of human 19p13.3 and mouse chromosome 10 allow identification of sequences at evolutionary breakpoints SO GENOME RESEARCH LA English DT Article ID MAJOR HISTOCOMPATIBILITY COMPLEX; FIELD GEL-ELECTROPHORESIS; SITU HYBRIDIZATION MAP; METRIC PHYSICAL MAP; UNCONVENTIONAL MYOSIN; GENE ORGANIZATION; HUMAN DNA; REGION; HUMAN-CHROMOSOME-19; RECOMBINATION AB A cosmid/bacterial artificial chromosome (BAC) contiguous (contig) map of human chromosome (HSA) 19p13.3 has been constructed, and over 50 genes have been localized to the contig. Genes and anonymous ESTs from approximate to 4000 kb of human 19p13.3 were placed on the central mouse chromosome 10 map by genetic mapping and pulsed-field gel electrophoresis (PFGE) analysis. A region of similar to 2500 kb of HSA 19p13.3 is collinear to mouse chromosome (MMU) 10. In contrast, the adjacent approximate to 1200 kb are inverted. Two genes are located in a 50-kb region after the inversion on MMU 10, followed by a region of homology to mouse chromosome 17. The synteny breakpoint and one of the inversion breakpoints has been localized to sequenced regions in human <5 kb in size. Both breakpoints are rich in simple tandem repeats, including (TCTG)n, (CT)n, and (GTCTCT)n, suggesting that simple repeat sequences may be involved in chromosome breaks during evolution. The overall size of the region in mouse is smaller, although no large regions are missing. Comparing the physical maps to the genetic maps showed that in contrast to the higher-than-average rate of genetic recombination in gene-rich telomeric region on HSA 19p33.3, the average rate of recombination is lower than expected in the homologous mouse region. This might indicate that a hot spot of recombination may have been lost in mouse or gained in human during evolution, or that the position of sequences along the chromosome (telomeric compared to the middle of a chromosome) is important for recombination rates. C1 Univ Michigan, Mental Hlth Res Inst, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Psychiat, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Human Genet, Ann Arbor, MI 48109 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Columbia Univ, New York, NY 10032 USA. Max Planck Inst Neurobiol, D-82152 Martinsried, Germany. RP Olsen, AS (reprint author), Univ Michigan, Mental Hlth Res Inst, Ann Arbor, MI 48109 USA. RI Burmeister, Margit/A-3157-2013; Puttagunta, Radhika/B-8664-2015 OI Burmeister, Margit/0000-0002-1914-2434; Puttagunta, Radhika/0000-0001-7674-8064 FU NINDS NIH HHS [NS32130, R01 NS032130] NR 50 TC 32 Z9 33 U1 0 U2 2 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 USA SN 1088-9051 J9 GENOME RES JI Genome Res. PD SEP PY 2000 VL 10 IS 9 BP 1369 EP 1380 DI 10.1101/gr.145200 PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 353BY UT WOS:000089254900012 PM 10984455 ER PT J AU Loging, WT Lal, A Siu, IM Loney, TL Wikstrand, CJ Marra, MA Prange, C Bigner, DD Strausberg, RL Riggins, GJ AF Loging, WT Lal, A Siu, IM Loney, TL Wikstrand, CJ Marra, MA Prange, C Bigner, DD Strausberg, RL Riggins, GJ TI Identifying potential tumor markers and antigens by database mining and rapid expression screening SO GENOME RESEARCH LA English DT Article ID GENE-EXPRESSION; DENDRITIC CELLS; CDNA-LIBRARY; NEUROMEDIN-B; ANNEXIN-I; CANCER; SPARC; CLONING; PROTEIN; TISSUE AB Genes expressed specifically in malignant tissue may have potential as therapeutic targets but have been difficult to locate for most cancers. The information hidden within certain public databases can reveal RNA transcripts specifically expressed in transformed tissue. To be useful, database information must be verified and a more complete pattern of tissue expression must be demonstrated. We tested database mining plus rapid screening by fluorescent-PCR expression comparison (F-PEC) as an approach to locate candidate brain tumor antigens. Cancer Genome Anatomy Project (CGAP) data was mined for genes highly expressed in glioblastoma multiforme. From 13 mined genes, seven showed potential as possible tumor markers or antigens as determined by further expression profiling. Now that large-scale expression information is readily available for many of the commonly occurring cancers, other candidate tumor markers or antigens could be located and evaluated with this approach. C1 Duke Univ, Med Ctr, Durham, NC 27710 USA. Washington Univ, Genome Sequencing Ctr, St Louis, MO 63108 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, IMAGE Consortium, Livermore, CA 94550 USA. NCI, Canc Genome Anat Project, Off Director, Bethesda, MD 20892 USA. RP Riggins, GJ (reprint author), Duke Univ, Med Ctr, Durham, NC 27710 USA. RI Marra, Marco/B-5987-2008 NR 47 TC 70 Z9 75 U1 0 U2 5 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 USA SN 1088-9051 J9 GENOME RES JI Genome Res. PD SEP PY 2000 VL 10 IS 9 BP 1393 EP 1402 DI 10.1101/gr.138000 PG 10 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 353BY UT WOS:000089254900014 PM 10984457 ER PT J AU Fredrickson, JK Zachara, JM Kennedy, DW Duff, MC Gorby, YA Li, SMW Krupka, KM AF Fredrickson, JK Zachara, JM Kennedy, DW Duff, MC Gorby, YA Li, SMW Krupka, KM TI Reduction of U(VI) in goethite (alpha-FeOOH) suspensions by a dissimilatory metal-reducing bacterium SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID SHEWANELLA-PUTREFACIENS MR-1; SAN-JOAQUIN VALLEY; X-RAY ABSORPTION; ZERO-VALENT IRON; URANIUM REDUCTION; FE(III)-REDUCING BACTERIA; ELECTRON-ACCEPTORS; HUMIC SUBSTANCES; CONTAMINATED AQUIFER; MICROBIAL REDUCTION AB Dissimilatory metal-reducing bacteria (DMRB) can utilize Fe(III) associated with aqueous complexes or solid phases, such as oxide and oxyhydroxide minerals, as a terminal electron acceptor coupled to the oxidation of H-2 or organic substrates. These bacteria are also capable of reducing other metal ions including Mn(IV), Cr(VI), and U(VI), a process that has a pronounced effect on their solubility and overall geochemical behavior. In spite of considerable study on an individual basis, the biogeochemical behavior of multiple metals subject to microbial reduction is poorly understood. To probe these complex processes, the reduction of U(VI) by the subsurface bacterium, Shewanella putrefaciens CN32, was investigated in the presence of goethite under conditions where the aqueous composition was controlled to vary U speciation and solubility. Uranium(VI), as the carbonate complexes UO2(CO3)(3(aq))(4-) and UO2(CO3)(2(aq))(2-) was reduced by the bacteria to U(IV) with or without goethite [alpha-FeOOH(s)] present. Uranium(VI) in 1,4-piperazinediethhane-sulfonic acid (PIPES) buffer that was estimated to be present predominantly as the U(VI) mineral metaschoepite [UO3. 2H(2)O((s))] was also reduced by the bacteria with or without goethite. In contrast, only similar to 30% of the U(VI) associated with a synthetic metaschoepite was reduced by the organism in the presence of goethite with 1 mM lactate as the electron donor. This may have been due to the formation of a layer of UO2(s) or Fe(OH)(3(s)) on the surface of the metaschoepite that physically obstructed further bioreduction. Increasing the lactate to a non-limiting concentration (10 mM) increased the reduction of U(VI) from metaschoepite to greater than 80% indicating that the hypothesized surface-veneering effect was electron donor dependent. Uranium(VI) was also reduced by bacterially reduced anthraquinone-2,6-disulfonate(AQDS) in the absence of cells, and by Fe(II) sorbed to goethite in abiotic control experiments. In the absence of goethite, uraninite was a major product of direct microbial reduction and reduction by AH(2)DS. These results indicate that DMRB, via a combination of direct enzymatic or indirect mechanisms, can reduce U(VI) to insoluble U(IV) in the presence of solid Fe oxides. Copyright (C) 2000 Elsevier Science Ltd. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Fredrickson, JK (reprint author), Pacific NW Natl Lab, MSIN P7-50,POB 999, Richland, WA 99352 USA. OI Kennedy, David/0000-0003-0763-501X NR 89 TC 220 Z9 229 U1 6 U2 72 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 2000 VL 64 IS 18 BP 3085 EP 3098 DI 10.1016/S0016-7037(00)00397-5 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 355RA UT WOS:000089397600002 ER PT J AU Heimsath, AM Chappell, J Dietrich, WE Nishiizumi, K Finkel, RC AF Heimsath, AM Chappell, J Dietrich, WE Nishiizumi, K Finkel, RC TI Soil production on a retreating escarpment in southeastern Australia SO GEOLOGY LA English DT Article DE erosion; cosmogenic nuclides; landscape evolution; geomorphology; tors ID COSMOGENIC NUCLIDES; CONTINENTAL-MARGIN; RATES; EVOLUTION; HIGHLANDS; DENUDATION; SURFACES; EROSION; PROFILE; MODELS AB The functional dependence of bedrock conversion to soil on the overlying soil depth (the soil production function) has been widely recognized as essential to understanding landscape evolution, but was quantified only recently. Here we report soil production rates for the first time at the base of a retreating escarpment, on the soil-mantled hilly slopes in the upper Bega Valley, southeastern Australia. Concentrations of Be-10 and Al-26 in bedrock from the base of the soil column show that soil production rates decline exponentially with increasing soil depth. These data define a soil production function with a maximum soil production rate of 53 m/m.y. under no soil mantle and a minimum of 7 m/m.y. under 100 cm of soil, thus constraining landscape evolution rates subsequent to escarpment retreat. The form of this function is supported by an inverse linear relationship between topographic curvature and soil depth that also suggests that simple creep does not adequately characterize the hillslope processes. Spatial variation of soil production shows a landscape out of dynamic equilibrium, possibly in response to the propagation of the escarpment through the field area within the past few million years. In addition, we present a method that tests the assumption of locally constant soil depth and lowering rates using concentrations of Be-10 and Al-26 On the surfaces of emergent tors. C1 Dartmouth Coll, Dept Earth Sci, Hanover, NH 03755 USA. Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 0200, Australia. Univ Calif Berkeley, Dept Geol & Geophys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA USA. RP Heimsath, AM (reprint author), Dartmouth Coll, Dept Earth Sci, Hanover, NH 03755 USA. NR 26 TC 158 Z9 158 U1 2 U2 26 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD SEP PY 2000 VL 28 IS 9 BP 787 EP 790 DI 10.1130/0091-7613(2000)28<787:SPOARE>2.0.CO;2 PG 4 WC Geology SC Geology GA 353HQ UT WOS:000089269100005 ER PT J AU Riebe, CS Kirchner, JW Granger, DE Finkel, RC AF Riebe, CS Kirchner, JW Granger, DE Finkel, RC TI Erosional equilibrium and disequilibrium in the Sierra Nevada, inferred from cosmogenic Al-26 and Be-10 in alluvial sediment SO GEOLOGY LA English DT Article DE cosmogenic nuclides; erosion rates; landscape evolution ID RATES; DENUDATION; UPLIFT AB We used cosmogenic Al-26 and Be-10 in stream sediment to measure landscape-scale erosion rates for topographically diverse catchments at seven Sierra Nevada sites. At three sites, erosion rates and hillslope gradients are strongly correlated, increasing with proximity to fault scarps and river canyons, which appear to have accelerated local base-level lowering rates, and thus increased catchment erosion rates by up to 15-fold. At four other sites, far from fault scarps and river canyons, erosion rates are much more uniform and less sensitive to average hillslope gradient. Our measurements show that contrasts in landscape erosion rates cannot be inferred from hillslope gradients alone, because landscapes can evolve toward a state of erosional equilibrium, in which steep and gentle slopes erode at similar rates. C1 Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. Purdue Univ, PRIME Lab, W Lafayette, IN 47907 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Riebe, CS (reprint author), Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. RI Kirchner, James/B-6126-2009; Riebe, Clifford/B-7670-2012 OI Kirchner, James/0000-0001-6577-3619; NR 24 TC 107 Z9 108 U1 2 U2 21 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD SEP PY 2000 VL 28 IS 9 BP 803 EP 806 DI 10.1130/0091-7613(2000)028<0803:EEADIT>2.3.CO;2 PG 4 WC Geology SC Geology GA 353HQ UT WOS:000089269100009 ER PT J AU Vasco, DW AF Vasco, DW TI An algebraic formulation of geophysical inverse problems SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE inverse problems; mathematical geophysics ID SPARSE POLYNOMIAL SYSTEMS; ALGORITHMS; RESULTANT; EQUATIONS AB Many geophysical inverse problems derive from governing partial differential equations with unknown coefficients. Alternatively, inverse problems often arise from integral equations associated with a Green's function solution to a governing differential equation. In their discrete form such equations reduce to systems of polynomial equations, known as algebraic equations. Using techniques from computational algebra one can address questions of the existence of solutions to such equations as well as the uniqueness of the solutions. The techniques are enumerative and exhaustive, requiring a finite number of computer operations. For example, calculating a bound to the total number of solutions reduces to computing the dimension of a linear vector space. The solution set itself may be constructed through the solution of an eigenvalue problem. The techniques are applied to a set of synthetic magnetotelluric values generated by conductivity variations within a layer. We find that the estimation of the conductivity and the electric field in the subsurface, based upon single-frequency magnetotelluric field values, is equivalent to a linear inverse problem. The techniques are also illustrated by an application to a magnetotelluric data set gathered at Battle Mountain, Nevada. Surface observations of the electric (E-y) and magnetic (H-x) fields are used to construct a model of subsurface electrical structure. Using techniques for algebraic equations it is shown that solutions exist, and that the set of solutions is finite. The total number of solutions is bounded above at 134 217 728. A numerical solution of the algebraic equations generates a conductivity structure in accordance with the current geological model for the area. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Vasco, DW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 69 TC 8 Z9 8 U1 0 U2 1 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 SEP PY 2000 VL 142 IS 3 BP 970 EP 990 DI 10.1046/j.1365-246x.2000.00188.x PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 350KY UT WOS:000089100900024 ER PT J AU Mlawer, EJ Brown, PD Clough, SA Harrison, LC Michalsky, JJ Kiedron, PW Shippert, T AF Mlawer, EJ Brown, PD Clough, SA Harrison, LC Michalsky, JJ Kiedron, PW Shippert, T TI Comparison of spectral direct and diffuse solar irradiance measurements and calculations for cloud-free conditions SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC ABSORPTION; WATER-VAPOR; MODEL; RADIOMETERS; FLUXES AB Ground-based spectral measurements of direct and diffuse solar irradiance from the Rotating Shadowband Spectroradiometer, taken in cloud-free conditions in Oklahoma in the fall of 1997, are compared over the spectral range 10000-28500 cm(-1) to corresponding calculations by an accurate multiple-scattering radiative transfer model. For each case analyzed, the aerosol optical depths used in the calculation were determined by fitting an Angstrom relation based on the ratio of the direct-beam measurements to a direct-beam calculation with no aerosols present. Also used in the calculation was a spectrally-independent aerosol single-scattering albedo chosen to provide agreement with the diffuse measurements. The spectral agreement between the measurements and calculations for the direct and diffuse irradiances is very good, providing strong evidence that in this spectral range there are no unmodeled molecular absorbers of significance to the atmospheric energy balance. Especially notable is the correspondence between the observations and calculations for a case characterized by a large amount of water vapor in the direct-beam path, directly contradicting the suggestion that water vapor absorbs more shortwave radiation than is represented in radiative transfer models. C1 Atmospher & Environm Res Inc, Cambridge, MA 02139 USA. SUNY Albany, Atmospher Sci Res Ctr, Albany, NY 12222 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Mlawer, EJ (reprint author), Atmospher & Environm Res Inc, 840 Mem Dr, Cambridge, MA 02139 USA. NR 19 TC 44 Z9 44 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 SEP 1 PY 2000 VL 27 IS 17 BP 2653 EP 2656 DI 10.1029/2000GL011498 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 353BW UT WOS:000089254700017 ER PT J AU Doll, WE Nyquist, JE Beard, LP Gamey, TJ AF Doll, WE Nyquist, JE Beard, LP Gamey, TJ TI Airborne geophysical surveying for hazardous waste site characterization on the Oak Ridge Reservation, Tennessee SO GEOPHYSICS LA English DT Article AB Airborne geophysical methods that were developed for mineral and petroleum exploration can, with some modification? be applied to environmental problems where large areas must be characterized. A helicopter survey that deployed magnetic, electromagnetic, and radiometric sensors carried out one of the first large-scale airborne environmental surveys at a U.S. government facility at Oak Ridge, Tennessee in 1993-1994. The survey included testing of a new airborne electromagnetic system designed specifically for environmental applications and for controlled held tests of magnetic systems. Helicopter-borne magnetic measurements were capable of discriminating groups of as few as ten metallic 208-liter (55-gallon) storage drums under representative field conditions. Magnetic and electromagnetic sensors were able to distinguish groups of metal-filled waste disposal trenches within disposal sites, but were unable to resolve individual trenches. Electromagnetic data proved to be the most effective airborne technique for geological mapping in this portion of the Appalachian fold-and thrust belt and for locating karst features. Radiometric measurements were useful both in geological mapping and in detecting zones of high radiation related to hazardous waste. The Oak Ridge survey proved valuable for quickly screening large areas and for locating anomalies for subsequent ground follow-up. On-board video was used to reduce the number of instances of ground follow-up by allowing the visual screening of anomalous areas. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Vanguard Geophys Inc, Mississauga, ON, Canada. RP Doll, WE (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Nyquist, Jonathan/B-2240-2010 NR 16 TC 19 Z9 19 U1 0 U2 4 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD SEP-OCT PY 2000 VL 65 IS 5 BP 1372 EP 1387 DI 10.1190/1.1444828 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 364KY UT WOS:000089892600003 ER PT J AU Alumbaugh, DL Newman, GA AF Alumbaugh, DL Newman, GA TI Image appraisal for 2-D and 3-D electromagnetic inversion SO GEOPHYSICS LA English DT Article ID NON-LINEAR APPRAISAL; MATRIX; RESISTIVITY; TOMOGRAPHY; INACCURATE; RESOLUTION AB Linearized methods are presented for appraising resolution and parameter accuracy in images generated with 2-D and 3-D nonlinear electromagnetic (EM) inversion schemes. When direct matrix inversion is used, the model resolution and a posteriori model covariance matrices can be calculated readily. By analyzing individual columns of the model resolution matrix, the spatial variation of the resolution in the horizontal and vertical directions can be estimated empirically. Plotting the diagonal of the model covariance matrix provides an estimate of how errors in the inversion process, such as data noise and incorrect a priori assumptions, map into parameter error and thus provides valuable information about the uniqueness of the resulting image. Methods are also derived for image appraisal when the iterative conjugate gradient technique is applied to solve the inverse. An iterative statistical method yields accurate estimates of the model covariance matrix as long as enough iterations are used. Although determining the entire model resolution matrix in a similar manner is computationally prohibitive, individual columns of this matrix can be determined. Thus, the spatial variation in image resolution can be determined by calculating the columns of this matrix for key points in the image domain and then interpolating between. Examples of the image analysis techniques are provided on 2-D and 3-D synthetic cross-well EM data sets as well as a field data set collected at Lost Hills oil field in central California. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Alumbaugh, DL (reprint author), Univ Wisconsin, Dept Civil & Environm Engn, 2258 Engn Hall, Madison, WI 53706 USA. RI Newman, Gregory/G-2813-2015 NR 30 TC 82 Z9 89 U1 1 U2 11 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD SEP-OCT PY 2000 VL 65 IS 5 BP 1455 EP 1467 DI 10.1190/1.1444834 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 364KY UT WOS:000089892600009 ER PT J AU Hoversten, GM Constable, SC Morrison, HF AF Hoversten, GM Constable, SC Morrison, HF TI Marine magnetotellurics for base-of-salt mapping: Gulf of Mexico field test at the Gemini structure SO GEOPHYSICS LA English DT Article ID PETROLEUM-EXPLORATION; INVERSION AB A sea-floor magnetotelluric (MT) survey was conducted over the Gemini subsalt petroleum prospect in the Gulf of Mexico (GOM) to demonstrate that the base of salt can be mapped using marine magnetotelluric (MMT) methods. The high contrast in electrical resistivity between the salt and the surrounding sediments provides an excellent target for MMT. The Gemini salt body, located at 28 degrees 46' N 88 degrees 36' W, is a relatively complex shape buried 2-5 km below the sea floor in I-km-deep water. Its geometry has been previously determined using 3-D seismic prestack depth migration with well log control. In order not to confuse limitations in interpretation technique with limitations in data acquisition, numerical forward and inverse modeling guided the survey design to locate a profile that would be amenable to 2-D inversion, even though the body was clearly 3-D. The seismic imaging of the base of salt along the chosen profile is considered good, thus providing a good control for testing the MT method. In many other areas of the GOM, and indeed other portions of the Gemini structure itself, seismic imaging of the base of salt is problematic. Data were collected using autonomous sea-floor data loggers equipped with induction coil magnetic sensors and electric field sensors consisting of silver-silver chloride electrodes connected to an ac-coupled amplifier originally designed for sea-floor controlled-source studies. Nine sites of excellent quality MT responses were obtained. Smooth 2-D inversion of the data produce a confined resistive anomaly at the comet location and depth, and recently developed sharp-boundary 2-D inversion recovers base of salt in excellent agreement with the seismic models. Simple perturbation analysis shows that base of salt has been resolved to within 5-10% of burial depth. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Scripps Inst Oceanog, La Jolla, CA 92093 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Hoversten, GM (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 30-1116, Berkeley, CA 94720 USA. RI Constable, Steven/B-8959-2008 NR 21 TC 39 Z9 45 U1 0 U2 5 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD SEP-OCT PY 2000 VL 65 IS 5 BP 1476 EP 1488 DI 10.1190/1.1444836 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 364KY UT WOS:000089892600011 ER PT J AU Keers, H Johnson, LR Vasco, DW AF Keers, H Johnson, LR Vasco, DW TI Acoustic crosswell imaging using asymptotic waveforms SO GEOPHYSICS LA English DT Article ID WAVE-FORM INVERSION; CROSSHOLE DATA; LEAST-SQUARES; TRAVEL-TIMES; TOMOGRAPHY; VELOCITY; ATTENUATION; SCATTERING; MIGRATION AB Seismic waveforms are inverted using an asymptotic method. The asymptotic method models amplitudes correctly at the caustics and takes nonstationary raypaths into account when computing the waveforms, and thus is an extension of geometrical ray theory. Using numerical differencing, partial derivatives of the data with respect to the model are computed. As expected, these partial derivatives (or sensitivity functions) are concentrated along, but not confined to, raypaths. The sensitivity functions enable the formulation of a waveform inversion algorithm, which is applied to a synthetic crosswell experiment and a laboratory crosswell experiment. The synthetic experiment shows the advantages of the waveform inversion method over conventional traveltime inversion methods. Boundaries of anomalies are better defined, and smearing is reduced. The waveform inversion produces a much lower misfit than the traveltime inversion. The goal of the laboratory experiment was the detection of a nonaqueous phase liquid (NAPL) in water saturated sand. The sand was imaged before and after injection of the NAPL. Using the waveform inversion method, low-velocity anomalies were imaged that correlate well with post-experiment determination of NAPL concentrations. The low-velocity anomaly defocuses the seismic energy. However, the amplitude reduction due to the low-velocity anomaly is not enough to explain the observed low amplitudes. We suggest that other mechanisms (such as multiple scattering, 3-D effects, or intrinsic attenuation) not included in the asymptotic waveform modeling play an important role in decreasing the amplitude. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Keers, H (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 90-1116,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 36 TC 9 Z9 9 U1 1 U2 2 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD SEP-OCT PY 2000 VL 65 IS 5 BP 1569 EP 1582 DI 10.1190/1.1444845 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 364KY UT WOS:000089892600020 ER PT J AU Hendricks, MB DePaolo, DJ Cohen, RC AF Hendricks, MB DePaolo, DJ Cohen, RC TI Space and time variation of delta O-18 and delta D in precipitation: Can paleotemperatnre be estimated from ice cores? SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID GENERAL-CIRCULATION MODEL; ANTARCTIC PENINSULA CLIMATE; ATMOSPHERIC CARBON-DIOXIDE; EDDY DIFFUSION-MODEL; LAST GLACIAL MAXIMUM; YOUNGER DRYAS; WATER-VAPOR; TEMPERATURE INVERSION; SURFACE TEMPERATURE; STABLE ISOTOPES AB A one-dimensional model of meridional water vapor transport is used to evaluate the factors that control the spatial and temporal variations of oxygen (delta(18)O) and hydrogen (delta D) isotopic ratios in global precipitation. The model extends Rayleigh descriptions of isotopes in precipitation by including (1) effects of recharge to air masses by evaporation and (2) horizontal transport by both eddy fluxes and advection. Globally, spatial variations in precipitation delta(18)O and delta D depend on the ratio of evaporation to the product of horizontal moisture flux and horizontal temperature gradient. At low latitudes, where this ratio is large, precipitation delta(18)O and delta D are closely tied to the isotopic ratios of oceanic evaporation. At high latitudes the ratio is small, and delta(18)O and delta D are controlled by the ratio of advective transport to eddy transport. Transport by eddy fluxes induces less fractionation than transport by advection, resulting in a smaller gradient of isotopic ratios with temperature. The model-predicted temporal relationships between delta(18)O (or delta D) ofantarctic precipitation and temperature do not necessarily coincide with the modern spatial relationship and depend strongly on the proximity of the precipitation site to the ocean evaporation source. Sensitivity of delta(18)O to temporal changes in local surface temperature is low at coastal sites and increases with distance inland. These results suggest a possible explanation of the apparent discrepancy between borehole temperature inversion estimates of glacial temperatures and temperatures inferred from the modern spatial delta(18)O - surface temperature relationship. C1 Univ Calif Berkeley, Dept Chem, Berkeley Ctr Isotope Geochem, Earth Sci Div,Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Geol & Geophys, Berkeley Ctr Isotope Geochem, Earth Sci Div,Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Hendricks, MB (reprint author), Princeton Univ, Dept Geosci, Guyot Hall, Princeton, NJ 08544 USA. RI Cohen, Ronald/A-8842-2011 OI Cohen, Ronald/0000-0001-6617-7691 NR 66 TC 61 Z9 65 U1 0 U2 18 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 2000 VL 14 IS 3 BP 851 EP 861 DI 10.1029/1999GB001198 PG 11 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 350EZ UT WOS:000089089000010 ER PT J AU Guilderson, TP Caldeira, K Duffy, PB AF Guilderson, TP Caldeira, K Duffy, PB TI Radiocarbon as a diagnostic tracer in ocean and carbon cycle modeling SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID GENERAL-CIRCULATION MODELS; NINO SOUTHERN OSCILLATION; POST-BOMB RADIOCARBON; EL-NINO; TROPICAL PACIFIC; WORLD OCEAN; SEA-ICE; ATMOSPHERE; C-14; VARIABILITY AB Models which are used to study the evolution of oceanic anthropogenic CO2 uptake in a warmer climate need to be adequately tested before their results are used to influence science and national policy, let alone predict future regional climate. In order to study circulation and the redistribution of carbon in the ocean, we have simulated the uptake and redistribution of bomb radiocarbon in a state of the art ocean general circulation model. The model does reasonably well in simulating the gross surface prebomb distribution of radiocarbon as well as some of the finer details resolved during Geochemical Ocean Section Study and World Ocean Circulation Experiment observations. In areas of downwelling the simulated surface-ocean bomb C-14 maxima occur too early with too much amplitude. This indicates inadequate vertical mixing and coupling between the wind driven and deeper regions of the ocean with a piling up of radiocarbon and CO2 in the upper ocean. This inadequacy will hamper efforts to predict ocean CO2 uptake on decadal to centennial timescales, the equivalent ventilation time of the respective water masses. These results are not specific to our model and indicate a systemic problem in many ocean models. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. Univ Calif Lawrence Livermore Natl Lab, Climate Syst Modeling Grp, Livermore, CA 94551 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Calif Lawrence Livermore Natl Lab, US DOE, Ctr Res Ocean Carbon Sequestrat, Livermore, CA USA. RP Guilderson, TP (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, L-397,7000 East Ave, Livermore, CA 94551 USA. RI Caldeira, Ken/E-7914-2011 NR 66 TC 24 Z9 25 U1 0 U2 7 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 2000 VL 14 IS 3 BP 887 EP 902 DI 10.1029/1999GB001192 PG 16 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 350EZ UT WOS:000089089000013 ER PT J AU Sultan, M Sturchio, NC Gheith, H Hady, YA El Anbeawy, M AF Sultan, M Sturchio, NC Gheith, H Hady, YA El Anbeawy, M TI Chemical and isotopic constraints on the origin of Wadi El-Tarfa ground water, Eastern Desert, Egypt SO GROUND WATER LA English DT Article ID ARID REGIONS; RECHARGE AB We evaluated the use of the renewable ground water resources of the Eastern Desert to develop sustainable agriculture in Upper Egypt, an alternative that could alleviate some of Egypt's dependence on water from the Nile River, Ground water from shallow aquifers in the Eastern Desert of Egypt, near the intersection of Wadi El-Tarfa and the Nile River, was analyzed for chemical compositions, stable isotope ratios, and tritium activities. The ground water has a range in total dissolved solids of 300 to 5000 mg/L, Values of delta D and delta(18)O range from -10 to +34 parts per thousand and -2 to +5.2 parts per thousand, respectively, and defines a line having a slope of 5.7 that intersects the meteoric water line at about delta D = -15 parts per thousand on a plot of delta D versus delta(18)O. These findings indicate that the water might have been derived by a combination of evaporation of and salt addition to regional precipitation. Only one sample could have been derived directly by evaporation and transpiration of modern Nile River mater. Salinization of the ground water could have occurred through dissolution of marine aerosol dry fallout, carbonate minerals, gypsum, and other trace evaporitic minerals at and near the ground surface. Tritium activities ranged from 0.04 to 12.9 TU (tritium units), indicating that all but one of the samples were derived at least partly from precipitation that occurred within the last 45 years. These data indicate that Nubian Aquifer paleowater is not a significant component of the shallow aquifers of this portion of the Eastern Desert. The most likely source of this ground water is sporadic flash flood events yielding locally voluminous recharge that accumulates in coarse sediments and fractured rock beneath alluvial channels. The magnitude of this renewable ground water resource and its potential for supporting sustainable agriculture require further investigation. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Cairo Univ, Ctr Environm Hazard Mitigat, Giza, Egypt. RP Sultan, M (reprint author), Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. NR 29 TC 14 Z9 15 U1 0 U2 0 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 2000 VL 38 IS 5 BP 743 EP 751 DI 10.1111/j.1745-6584.2000.tb02710.x PG 9 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA 349VM UT WOS:000089066300015 ER PT J AU Rassabi, J Riha, BD Haas, JW Eddy-Dilek, CA Kreeger, AGL Carrabba, M Hyde, WK Bello, J AF Rassabi, J Riha, BD Haas, JW Eddy-Dilek, CA Kreeger, AGL Carrabba, M Hyde, WK Bello, J TI Field tests of a DNAPL characterization system using cone penetrometer-based Raman spectroscopy SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article AB Cone penetrometer test (CPT) based Raman spectroscopy was used to identify separate phase tetrachloroethylene (PCE) and trichloroethylene (TCE) contamination in the subsurface at two locations during field tests conducted at the U.S. Department of Energy's (DOE) Savannah River site. Clear characteristic Raman spectral peaks for PCE and TCE were observed at two sites and several depths during CPT deployment. Because of the uniqueness of a Raman spectrum for a given compound, these data are compelling evidence of the presence of the two compounds. The Raman spectral results correlated with high PCE and TCE concentrations in soil samples collected from the same subsurface zones, confirming that the method is a viable dense nonaqueous phase liquid (DNAPL) characterization technique. The Raman spectroscopic identification of PCE and TCE in these tests represents the first time that DNAPLs have been unequivocally located in the subsurface by an in situ technique. The detection limit of the Raman spectroscopy is related to the probability of contaminant droplets appearing on the optical window in the path of the probe light. Based on data from this fieldwork, the Raman technique may require a threshold quantity of DNAPL to provide an adequate optical cross section for spectroscopic response. The low aqueous solubility of PCE and TCE and relatively weak optical intensity of the Raman signal precludes the detection of aqueous phase contaminants by this method, making it selective for DNAPL contaminants only. C1 Savannah River Technol Ctr, WSRC, Aiken, SC 29808 USA. Appl Res Associates, Royalton, VT 05068 USA. RP Rassabi, J (reprint author), Savannah River Technol Ctr, WSRC, Bldg 773-42A, Aiken, SC 29808 USA. NR 10 TC 1 Z9 1 U1 1 U2 4 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD FAL PY 2000 VL 20 IS 4 BP 72 EP 81 PG 10 WC Water Resources SC Water Resources GA 375UM UT WOS:000165419700007 ER PT J AU Hadley, SA Meyer, NR Fleischer, RL Cavallo, A AF Hadley, SA Meyer, NR Fleischer, RL Cavallo, A TI Eyeglass lenses for personal radon dosimetry SO HEALTH PHYSICS LA English DT Article DE calibration; radon; detector; alpha-track; dose assessment ID ALPHA-RECOIL DAMAGE; LUNG-CANCER; EXPOSURE; RN-222; WOMEN AB Eyeglass lenses are commonly composed of allyldiglycol carbonate (CR-39), an alpha-particle detecting plastic, thus making such lenses personal radon dosimeters. Samples of such lenses have been etched to reveal that radon and radon progeny alpha tracks can be seen in abundance, and sensitivities have been calibrated in radon chambers as a primary calibration and with a uranium-based source of alpha particles as a convenient secondary standard. Natural, environmental (fossil) track densities ranged from 3,000 to 25,000 cm(-2) for eyeglasses that had been worn for various times from 1 to nearly 5 y. Average radon concentrations to which the wearers were exposed are inferred to be in the range 20 to 130 Bq m(-3) (0.5 to 3.5 pCi L-1). Procedures for consistent, meaningful readout are described. C1 Union Coll, FW Olin Ctr, Dept Geol, Schenectady, NY 12308 USA. US DOE, Environm Measurements Lab, New York, NY 10014 USA. NR 19 TC 8 Z9 8 U1 0 U2 0 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 SEP PY 2000 VL 79 IS 3 BP 242 EP 250 DI 10.1097/00004032-200009000-00003 PG 9 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 343ZD UT WOS:000088732400003 PM 10949248 ER PT J AU Carter, PH Pines, DJ Rudd, LV AF Carter, PH Pines, DJ Rudd, LV TI Approximate performance of periodic hypersonic cruise trajectories for global reach (Reprinted from Journal of Aircraft, vol 35, pg 857-867, 1998) SO IBM JOURNAL OF RESEARCH AND DEVELOPMENT LA English DT Reprint ID VEHICLE AB This paper develops the analytical framework to compare the approximate performance of periodic hypersonic cruise trajectories with previously proposed hypersonic trajectory profiles for global reach. Specifically, range, Delta V, and payload-carrying capacity are evaluated for various trajectory types to illustrate the enhanced performance achieved by dying periodic hypersonic cruise trajectories with existing hypersonic vehicle aerodynamic, propulsion, and structures technology. Analytical results reveal that periodic hypersonic cruise trajectories achieve better fuel-consumption savings and deliver more payload over long distances (similar to 20,000 km) than other trajectory types proposed for high-speed flight, Over 20% improvement in fuel consumption savings is possible for a Mach 10 vehicle with a modest LID of 4, and a curve-fitted rocket-based combined cycle engine model. C1 Univ Calif Lawrence Livermore Natl Lab, Mech Engn Div, Livermore, CA 94550 USA. Univ Maryland, Dept Aerosp Engn, College Pk, MD 20742 USA. RP Carter, PH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Mech Engn Div, Livermore, CA 94550 USA. NR 13 TC 0 Z9 1 U1 1 U2 2 PU IBM CORP PI ARMONK PA OLD ORCHARD RD, ARMONK, NY 10504 USA SN 0018-8646 J9 IBM J RES DEV JI IBM J. Res. Dev. PD SEP PY 2000 VL 44 IS 5 BP 703 EP 714 PG 12 WC Computer Science, Hardware & Architecture; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA 355MD UT WOS:000089388700005 ER PT J AU Tsapin, AI Goldfeld, MG McDonald, GD Nealson, KH Moskovitz, B Solheid, P Kemner, KM Kelly, SD Orlandini, KA AF Tsapin, AI Goldfeld, MG McDonald, GD Nealson, KH Moskovitz, B Solheid, P Kemner, KM Kelly, SD Orlandini, KA TI Iron(VI): Hypothetical candidate for the martian oxidant SO ICARUS LA English DT Article ID POTASSIUM FERRATE; OXIDATION; MARS; MECHANISM; KINETICS; SOIL; EXCHANGE; PEROXIDE; SURFACE; MOSSBAUER AB As a result of the Viking missions of the early 1970s, the presence of a strong oxidant in martian soil was suggested. Here we present a hypothesis, testable by near-term missions, that iron(VI) is a likely contributor to the martian oxidative pool. In this context, ferrate(VI) salts, with FeO42- anion, were studied for their spectral and oxidative properties. Ferrate(VI) has distinctive spectroscopic features that make it available for detection by remote sensing reflectance spectra and contact measurements via Mossbauer spectroscopy, and the relevant miniaturized instrumentation has been developed or is under way, while for the returned samples XANES spectroscopy is shown to be a method of choice. Ferrate(VI) is capable of splitting water to yield molecular oxygen, and oxidizing organic carbon into CO2. These activities were strongly abated after treatment at elevated temperatures, similar to observations with martian soil samples in the Viking mission. (C) 2000 Academic Press. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA. Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Tsapin, AI (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 183-301, Pasadena, CA 91109 USA. RI ID, MRCAT/G-7586-2011 NR 48 TC 32 Z9 35 U1 2 U2 13 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD SEP PY 2000 VL 147 IS 1 BP 68 EP 78 DI 10.1006/icar.2000.6437 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 349WG UT WOS:000089068100007 ER PT J AU Hughes, RJ Williams, CP AF Hughes, RJ Williams, CP TI Quantum computing: The final frontier? SO IEEE INTELLIGENT SYSTEMS & THEIR APPLICATIONS LA English DT Editorial Material ID COMPUTATION; ALGORITHM; CRYPTOGRAPHY C1 Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Stanford Univ, Stanford, CA 94305 USA. RP Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. EM hughes@lanl.gov; colin.p.williams@jpl.nasa.gov NR 29 TC 4 Z9 4 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 1094-7167 J9 IEEE INTELL SYST APP JI IEEE Intell. Syst. Appl. PD SEP-OCT PY 2000 VL 15 IS 5 BP 10 EP 18 DI 10.1109/5254.889102 PG 9 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 376UE UT WOS:000165474500004 ER PT J AU Mead, N Anderson, R McGraw, G Machanick, P Bollinger, T Shimeall, T Pyster, A Brown, D Draier, E Schmidt, H AF Mead, N Anderson, R McGraw, G Machanick, P Bollinger, T Shimeall, T Pyster, A Brown, D Draier, E Schmidt, H TI Information security policy SO IEEE SOFTWARE LA English DT Editorial Material C1 Software Engn Inst, Survivable Network Anal Team, Pittsburgh, PA 15213 USA. Software Engn Inst, Networked Syst Survivabil Program, Tech Staff, Cert Coordinat Ctr, Pittsburgh, PA 15213 USA. Carnegie Mellon Univ, Master Software Engn Program, Pittsburgh, PA 15213 USA. Carnegie Mellon Univ, Master Informat Syst Management Program, Pittsburgh, PA 15213 USA. Univ Cambridge, Comp Lab, Cambridge CB2 3QG, England. Sandia Natl Labs, Comp Secur Technol Dept, Livermore, CA 94550 USA. Univ S Africa, Dept Comp Sci, Witwatersrand, South Africa. Citigal, Sterling, VA USA. FAA, Washington, DC USA. Microsoft Corp, Corp Secur Grp, Redmond, WA 98052 USA. RP Mead, N (reprint author), Software Engn Inst, Survivable Network Anal Team, 5000 Forbes Ave, Pittsburgh, PA 15213 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0740-7459 J9 IEEE SOFTWARE JI IEEE Softw. PD SEP-OCT PY 2000 VL 17 IS 5 BP 26 EP 32 PG 7 WC Computer Science, Software Engineering SC Computer Science GA 357YV UT WOS:000089530800015 ER PT J AU Dudley, DG Pao, HY Hill, DA AF Dudley, DG Pao, HY Hill, DA TI Special issue - In memoriam: James R. Wait - Introduction SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Editorial Material C1 US Dept Commerce, NIST, Boulder, CO 80303 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NIST, Radio Frequency Technol Div, Boulder, CO 80305 USA. RP Dudley, DG (reprint author), US Dept Commerce, NIST, Boulder, CO 80303 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD SEP PY 2000 VL 48 IS 9 BP 1287 EP 1288 DI 10.1109/TAP.2000.898759 PG 2 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 399QQ UT WOS:000166824200003 ER PT J AU Pao, HY Wait, JR AF Pao, HY Wait, JR TI Electromagnetic induction and surface impedance in a half-space from an overhead moving current system SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE electromagnetic (EM) induction; geological measurements; geophysics; surface impedance AB How does an overhead current system having a velocity v influence the electromagnetic (EM) fields and the surface impedance as measured on the ground? We attempt to answer this question in this paper, A formulation is given for the fields produced by a current system having a uniform translational velocity. The numerical results that reflect the influence of velocity on the surface impedance at the air/earth boundary are presented. The relativity effect is not considered. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Pao, HY (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD SEP PY 2000 VL 48 IS 9 BP 1301 EP 1305 DI 10.1109/8.898762 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 399QQ UT WOS:000166824200006 ER PT J AU Ermer, JJ Mosher, JC Huang, MX Leahy, RM AF Ermer, JJ Mosher, JC Huang, MX Leahy, RM TI Paired MEG data set source localization using recursively applied and projected (RAP) MUSIC SO IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING LA English DT Article DE array signal processing; magnetoencephalography; signal subspace methods; source localization ID EEG AB An important class of experiments in functional brain mapping involves collecting pairs of data Corresponding to separate "Task" and "Control'' conditions. The data are then analyzed to determine what activity occurs during the Task experiment but not in the Control, Here me describe a new method for processing paired magnetoencephalographic (MEG) data sets using our recursively applied and projected multiple signal classification (RAP-MUSIC) algorithm. In this method the signal subspace of the Task data is projected against the orthogonal complement of the Control data signal subspace to obtain a subspace which describes spatial activity unique to the Task, A RAP-MUSIC localization search is then performed on this projected data to localize the sources which are active in the Task but not in the Control data. in addition to dipolar sources, effective blocking of more complex sources, e.g., multiple synchronously activated dipoles or synchronously activated distributed source activity, is possible since these topographies are well-described by the Control data signal subspace, Unlike previously published methods, the proposed method is shown to be effective in situations where the time series associated with Control and Task activity possess significant cross correlation. The method also allows for straightforward determination of the estimated time series of the localized target sources, A multiepoch MEG simulation and a phantom experiment are presented to demonstrate the ability of this method to successfully identify sources and their time series in the Task data. C1 Univ So Calif, Signal & Image Proc Inst, Los Angeles, CA 90089 USA. Raytheon Syst Co, El Segundo, CA 90245 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ New Mexico, Albuquerque, NM 87131 USA. RP Leahy, RM (reprint author), Univ So Calif, Signal & Image Proc Inst, Los Angeles, CA 90089 USA. FU NIMH NIH HHS [R01-MH53213] NR 17 TC 11 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9294 J9 IEEE T BIO-MED ENG JI IEEE Trans. Biomed. Eng. PD SEP PY 2000 VL 47 IS 9 BP 1248 EP 1260 DI 10.1109/10.867959 PG 13 WC Engineering, Biomedical SC Engineering GA 355DX UT WOS:000089371500013 PM 11008426 ER PT J AU Casada, DA Kueck, JD Staunton, RH Webb, MC AF Casada, DA Kueck, JD Staunton, RH Webb, MC TI Efficiency testing of motors powered from pulse-width modulated adjustable speed drives SO IEEE TRANSACTIONS ON ENERGY CONVERSION LA English DT Article DE drives; efficiency; inverters; motors AB This is a report of efficiency testing of an induction motor powered from three different Pulse Width Modulated adjustable speed drives. The motor was operated at a range of speeds and torques, and each drive was operated at the highest, lowest, and an in-between carrier frequency. The motor was a typical NEMA design B motor, and the drives were typical, industrial scalar drives using the default volts/Hz setting. The testing showed that the drive efficiencies remained above 90% until torque was lowered to below 20% of rated torque, Combined motor and drive efficiencies remained above 80% until speeds or horsepower loads were lowered to below 20% of rated torque. The test was performed using a unique data acquisition scheme that permitted acquisition of a large number of torque settings for each speed selection. C1 Oak Ridge Natl Lab, Lockheed Martin Energy Syst Res Corp, Oak Ridge, TN 37831 USA. Univ Tennessee, Knoxville, TN USA. RP Casada, DA (reprint author), Oak Ridge Natl Lab, Lockheed Martin Energy Syst Res Corp, Oak Ridge, TN 37831 USA. NR 4 TC 6 Z9 7 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 0885-8969 J9 IEEE T ENERGY CONVER JI IEEE Trans. Energy Convers. PD SEP PY 2000 VL 15 IS 3 BP 240 EP 244 DI 10.1109/60.875487 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA 366EK UT WOS:000089991700002 ER PT J AU Ropp, ME Begovic, M Rohatgi, A Kern, GA Bonn, RH Gonzalez, S AF Ropp, ME Begovic, M Rohatgi, A Kern, GA Bonn, RH Gonzalez, S TI Determining the relative effectiveness of islanding detection methods using phase criteria and nondetection zones SO IEEE TRANSACTIONS ON ENERGY CONVERSION LA English DT Article AB Islanding of a utility-interactive photovoltaic (UIPV) system occurs if the UIPV system continues to power a section of the utility system after that section has been disconnected from the utility source. Since islanding creates hazards for personnel and equipment, UIPV systems are required to detect and prevent it. It is desirable to have a simplified method of determining which islanding detection methods (IDM's) are most effective. In this paper, a previously described method for finding the nondetection zones (NDZ's) of IDM's is experimentally verified. This method is used to determine the NDZ's of several common IDM's. These results indicate that, of the IDM's discussed in this paper: 1) Sandia Frequency Shift (SFS) is most effective; 2) the worst-case loads are low-power loads that are near resonance at the line frequency and have a large capacitance and small inductance (a high value of the quality factor Q). C1 S Dakota State Univ, Dept Elect Engn, Brookings, SD 57007 USA. Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. Ascens Technol Inc, Boulder, CO 80301 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ropp, ME (reprint author), S Dakota State Univ, Dept Elect Engn, Brookings, SD 57007 USA. NR 9 TC 156 Z9 186 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 0885-8969 J9 IEEE T ENERGY CONVER JI IEEE Trans. Energy Convers. PD SEP PY 2000 VL 15 IS 3 BP 290 EP 296 DI 10.1109/60.875495 PG 7 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA 366EK UT WOS:000089991700010 ER PT J AU Cantu-Paz, E AF Cantu-Paz, E TI Markov chain models of parallel genetic algorithms SO IEEE TRANSACTIONS ON EVOLUTIONARY COMPUTATION LA English DT Article DE communications topology; Markov chains; migration rate; multiple populations; parallel genetic algorithms AB Implementations of parallel genetic algorithms (GAs) with multiple populations are common, but they introduce several parameters whose effect on the quality of the search is not well understood. Parameters such as the number of populations, their size, the topology of communications, and the migration fate have to be set carefully to reach adequate solutions. This paper presents models that predict the effects of the parallel GA's parameters on its search quality, The paper reviews some recent results on the case where each population is connected to all the others and the migration rate is set to the maximum value possible. This bounding case is the simplest to analyze, and it introduces the methodology that is used in the remainder of the paper to analyze parallel GAs with arbitrary migration rates and communication topologies, This investigation considers that migration occurs only after each population converges: then, incoming individuals are incorporated into the populations and the algorithm restarts. The models find the probability that each population converges to the correct solution after each restart, and also calculate the long-run chance of success. The accuracy of the models is verified with experiments using one additively decomposable function. C1 Univ Illinois, Dept Comp Sci, Urbana, IL 61801 USA. Univ Illinois, Illinois Genet Algorithms Lab, Urbana, IL 61801 USA. RP Lawrence Livermore Natl Lab, Ctr Applied Sci Comp, Livermore, CA 94550 USA. EM cantupaz@llnl.gov NR 21 TC 20 Z9 21 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1089-778X EI 1941-0026 J9 IEEE T EVOLUT COMPUT JI IEEE Trans. Evol. Comput. PD SEP PY 2000 VL 4 IS 3 BP 216 EP 226 DI 10.1109/4235.873233 PG 11 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA 362WB UT WOS:000089800300002 ER PT J AU Ashikhmin, AE Barg, A Litsyn, SN AF Ashikhmin, AE Barg, A Litsyn, SN TI A new upper bound on the reliability function of the Gaussian channel SO IEEE TRANSACTIONS ON INFORMATION THEORY LA English DT Article; Proceedings Paper CT IEEE Information Theory Workshop CY JUN 20-25, 1999 CL SOUTH AFRICA SP IEEE DE distance distribution; error probability of decoding; Jacobi polynomials; spherical codes ID DISTANCE DISTRIBUTION; CODES AB We derive a new upper bound on the exponent of error probability of decoding for the best possible codes in the Gaussian channel. This bound is tighter than the known upper bounds (the sphere-packing and minimum-distance bounds proved in Shannon's classical 1959 paper and their low-rate improvement by Kabatiansky and Levenshtein), The proof is accomplished by studying asymptotic properties of codes on the sphere Sn-1(FB). First we prove a general lower bound on the distance distribution of codes of large size, To derive specific estimates of the distance distribution, we study the asymptotic behavior of Jacobi polynomials P-k(ak, bk) as k --> infinity. Since on the average there are many code vectors in the vicinity of the transmitted vector x, one can show that the probability of confusing x and one of these vectors cannot be too small, This proves a lower bound on the error probability of decoding and the upper bound announced in the title. C1 Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Tel Aviv Univ, Dept Elect Engn Syst, IL-69978 Tel Aviv, Israel. RP Ashikhmin, AE (reprint author), Bell Labs, Lucent Technol, Rm 2C-179, Murray Hill, NJ 07974 USA. NR 37 TC 21 Z9 23 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9448 J9 IEEE T INFORM THEORY JI IEEE Trans. Inf. Theory PD SEP PY 2000 VL 46 IS 6 BP 1945 EP 1961 DI 10.1109/18.868471 PG 17 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 354JF UT WOS:000089325800001 ER PT J AU Sin, K Mao, M Chien, C Funada, S Miloslavsky, L Tong, HC Gupta, S AF Sin, K Mao, M Chien, C Funada, S Miloslavsky, L Tong, HC Gupta, S TI Low resistance spin-dependent tunneling junctions with naturally oxidized tunneling barrier SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE giant magnetoresistance; magnetic films and devices; magnetic materials for heads; magnetic spin tunneling ID MAGNETORESISTANCE AB We investigated the effect of aluminum thickness on RA (resistance . area product) and MR ratio in spin-dependent tunnel junctions. Very low RA values below 40 Omega mum(2) and a maximum MR ratio of 6% were obtained in Ni18Fe19/Al2O3/Ni81Fe19 tunneling junctions fabricated using natural oxidation of aluminum. The MR ratio significantly increased with use of Co90Fe10 electrodes. Using natural oxidation of 6 Angstrom aluminum, RA and MR ratio of these junctions are similar to 50 Omega mum(2) and similar to 28%, respectively, The MR ratio and the junction resistance strongly depend on the aluminum thickness. The optimum thickness of aluminum is 6-7 Angstrom for natural oxidation. C1 Read Rite Corp, Fremont, CA 94539 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Veeco, Orangeburg, NY 10962 USA. RP Sin, K (reprint author), Read Rite Corp, Fremont, CA 94539 USA. NR 9 TC 10 Z9 10 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 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2818 EP 2820 DI 10.1109/20.908599 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700213 ER PT J AU Mao, M Cerjan, C Law, B Grabner, F Miloslavsky, L Chien, C AF Mao, M Cerjan, C Law, B Grabner, F Miloslavsky, L Chien, C TI Enhanced spin-valve giant magneto-resistance in non-exchange biased sandwich films SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE GMR; sandwich; spin-valve; seed layer; coercivity; nano-oxide layer; specular reflection ID MAGNETORESISTANCE AB A large giant magnetoresistance (GMR) value of 7.5% has been measured in simple NiFeCo(1)/Cu/NiFeCo(2) sandwich films grown on a 30 Angstrom Cr seed layer. This spin-valve GMR effect is consistent with the differential switching of the two NiFeCo layers due to an enhanced coercivity of the NiFeCo(1) layer grown on the Cr seed layer. A change in growth texture of the NiFeCo(1) layer from fee (111) to bce (110) crystallographic orientation leads to an increase in magnetic anisotropy and an enhancement in coercivity, The GMR value increases to 8.7% when a thin CoFe interfacial enhancing layer is incorporated. Further enhancement in GMR values up to 14% is seen in the sandwich films by nano-oxide layer formation. The specular reflection at the oxide/magnetic layer interface further extends the mean free path of spin-polarized electrons. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. ReadRite Corp, Fremont, CA 94539 USA. RP Mao, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-395, Livermore, CA 94550 USA. NR 5 TC 2 Z9 2 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 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2866 EP 2868 DI 10.1109/20.908611 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700225 ER PT J AU Liu, CX Yu, CT Jiang, HM Mankey, GJ AF Liu, CX Yu, CT Jiang, HM Mankey, GJ TI Epitaxial growth and magnetic properties of Ni80Fe20/Fe60Mn40 bilayers on H-Si(110) using a Cu buffer layer SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE crystallinity; Cu buffer layer; epitaxial growth; exchange anisotropy ID EXCHANGE; CU(111); FILMS AB A very thin Cu (similar to1 nm) buffer layer on Si(110) is enough to induce Ni80Fe20/Fe60Mn40 (111) epitaxial growth. The film surface roughness increases with increasing Cu thickness's, The crystallinity improves as the Cu buffer thickness increases. The uniaxial anisotropy of the pinned Ni80Fe20 was greatly enhanced in the samples with thick Cu (>10 nm), This reflects the great effect of film crystallinity on exchange anisotropy. C1 Univ Alabama, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. Argonal Natl Lab, Argonal, IL USA. RP Liu, CX (reprint author), Univ Alabama, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. RI Mankey, Gary/G-9110-2011 OI Mankey, Gary/0000-0003-3163-5159 NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2896 EP 2898 DI 10.1109/20.908620 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700234 ER PT J AU Liu, F Yu, C Shen, L Barnard, J Mankey, GJ AF Liu, F Yu, C Shen, L Barnard, J Mankey, GJ TI The magnetic properties of cobalt films produced by glancing angle deposition SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE cobalt films; electron-beam evaporation; perpendicular anisotropy; magnetic particles ID THIN-FILMS; GROWTH AB The magnetic properties of columnar cobalt films fabricated by glancing angle deposition were investigated. Varying the azimuthal rotation speed and polar angle of incidence of the vapor flux produces films with different microstructures, The magnetic anisotropies and squareness ratio between perpendicular and in-plane hysteresis loops are measured for various films and found to have a weak dependence on the azimuthal rotation speed of the substrate at the polar angle of 75 degrees, The squareness ratio is strongly affected by the variation of the polar angle of incidence of the vapor flux, At an azimuthal rotation speed of 0.092 rev/s and polar angle of 83 degrees, the Co film is composed of well-separated columns with the packing fraction of 0.3. The hysteresis loops of this film exhibit a perpendicular anisotropy with the squarness ratio of 1.6. The X-ray diffraction spectrum shows that the Co columns possess a strong (2112) preferred orientation, which indicates that the perpendicular anisotropy is from shape anisotropy and not from crystalline anisotropy. C1 Univ Alabama, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. RP Liu, F (reprint author), Univ Alabama, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. RI Mankey, Gary/G-9110-2011 OI Mankey, Gary/0000-0003-3163-5159 NR 5 TC 13 Z9 13 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2939 EP 2941 DI 10.1109/20.908634 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700248 ER PT J AU Vavassori, P Donzelli, O Callegaro, L Grimsditch, M Metlushko, V AF Vavassori, P Donzelli, O Callegaro, L Grimsditch, M Metlushko, V TI Magnetic domain structure and magnetic reversal in elliptical dot arrays SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE end domains; magnetization reversal; magnetooptics; micromagnetics ID SHAPE; END AB We present a joint magnetic force microscopy analysis and Magneto-optical Kerr measurements of dot arrays that contain elliptical elements with different shape. In particular we have investigated the influence of the element shape on the domain structure in the remnant state. The single- or multiple domain nature of the magnetization at remanence is shown to depend strongly on how rounded or pointed each element is. C1 Univ Ferrara, Dipartimento Fis, INFM, I-44100 Ferrara, Italy. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Politecn Milan, Dipartimento Fis, INFM, I-20134 Milan, Italy. Ist Elettrotecn Nazl Galileo Ferraris, I-10135 Turin, Italy. RP Vavassori, P (reprint author), Univ Ferrara, Dipartimento Fis, INFM, I-44100 Ferrara, Italy. RI Callegaro, Luca/I-8496-2012; Vavassori, Paolo/B-4299-2014; OI Vavassori, Paolo/0000-0002-4735-6640; Callegaro, Luca/0000-0001-5997-9960 NR 8 TC 12 Z9 12 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 2993 EP 2995 DI 10.1109/20.908652 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700265 ER PT J AU Lee, SJ Jiles, DC AF Lee, SJ Jiles, DC TI Geometrical enhancements to permanent magnet flux sources: Application to energy efficient magnetocaloric refrigeration systems SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE finite element modeling; magnet array; magnetic refrigeration; permanent magnets ID DESIGN AB The research reported here shows that a magnetic flux density B far in excess of the magnetic remanence BR Of a permanent magnet material can be achieved by arranging permanent magnets in the form of hollow cylindrical shells (magic rings), or hollow spherical shells (magic spheres) with additional modifications. In this paper, we report on three additional modifications to enhance the magnetic flux density in the pole gap, i) by changing the cross sectional shape of the permanent magnet array into an ellipse instead of a circle, ii) by including a high remanence flux concentrator close to the aig gap and iii) by surrounding the magnet array with a soft magnetic shell which acts as a flux return path, In this way flux densities in excess of 3 Tesla can be achieved in a 23.5 mm(2) x 15.2 mm pole gap using NdFeB magnets with remanence of only 1.2 Tesla. The enhanced magnetic flux density can be used for magnetic refrigeration systems, which require sources of magnetic field typically above 1.5 Tesla. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Lee, SJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 7 TC 14 Z9 17 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 3105 EP 3107 DI 10.1109/20.908699 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700302 ER PT J AU Melikhov, YY Lo, CCH Jiles, DC Tomas, I Kadlecova, J Perevertov, OV AF Melikhov, YY Lo, CCH Jiles, DC Tomas, I Kadlecova, J Perevertov, OV TI Application of Preisach analysis to detection of fatigue damage SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE load-controlled fatigue; magnetic hysteresis; nondestructive evaluation; Preisach model AB Measurements of hysteresis loops, initial magnetization curve and families of differential permeability curves were made on a series of 0.05 and 0.1 wt% C Fe-C samples subjected to fatigue under load control. Preisach-like functions were calculated using the permeability data. Based on these functions a new parameter was identified which was found to decrease monotonically with increasing number of fatigue cycles whereas the classical magnetic hysteresis loop parameters remained constant. This result indicates that the method may be used as a nondestructive evaluation (NDE) technique for estimating expended fatigue life of ferromagnetic materials. C1 Inst Phys, Prague 18221, Czech Republic. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Melikhov, YY (reprint author), Inst Phys, Prague 18221, Czech Republic. RI Jiles, David/H-9548-2012; Tomas, Ivan/C-6968-2013; Perevertov, Oleksiy/H-1373-2014 NR 7 TC 3 Z9 3 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 3211 EP 3213 DI 10.1109/20.908741 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700334 ER PT J AU Clark, AE Restorff, JB Wun-Fogle, M Lograsso, TA Schlagel, DL AF Clark, AE Restorff, JB Wun-Fogle, M Lograsso, TA Schlagel, DL TI Magnetostrictive properties of body-centered cubic Fe-Ga and Fe-Ga-Al alloys SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE actuator; Fe-Ga; Fe-Ga-Al; magnetostriction; structural materials; transduction AB The magnetic and magnetostrictive properties of Fe1-xGax and Fe1-x-yGaxAly (x + y < 0.3) single crystals were measured under compressive stresses up to 120 MPa and in magnetic fields up to 1 kOe. Values of (100) exceeding 200 ppm were observed in samples of Fe83Ga17 from 180 K to room temperature. Only a small monotonic decrease in magnetostriction with temperature was found. On the other hand, lambda (111) maintained small negative values close to those of b.c.c. Fe. In all cases, no higher order magnetostrictive terms were detectable. With 15 to 20 atomic percent replacement of Fe by Ga, the magnetizations remain high (M-s congruent to 1.8 T) and the magnetic anisotropies reduced (K-1 congruent to 10(4) J/m(3)). Values of the 'stiff' (high magnetic field) Young's modulus, Bulk modulus, Poison's ratio, and elastic constant c(11)-c(12) for Fe85Ga15 at room temperature are, respectively, 77 GPa, 111 GPa, 0.38, and 56 GPa. C1 Clark Associates, Adelphi, MD 20783 USA. USN, Ctr Surface Warfare, Carderock Div, Bethesda, MD 20817 USA. Ames Lab, Ames, IA 50011 USA. RP Clark, AE (reprint author), Clark Associates, Adelphi, MD 20783 USA. NR 9 TC 364 Z9 384 U1 6 U2 65 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 2000 VL 36 IS 5 BP 3238 EP 3240 DI 10.1109/20.908752 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700343 ER PT J AU Chen, Y Jiles, DC AF Chen, Y Jiles, DC TI The magnetomechanical effect under torsional stress in a cobalt ferrite composite SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE law of approach; magnetomechanical effect; torsional stress ID MAGNETIZATION AB Metal bonded cobalt ferrite composites are candidate materials for torque sensor applications because of their high magnetostriction lambda and particularly the high value of the derivative d lambda / dH. This paper reports on recent investigations of the magnetomechanical effect under torsional stress in (CoFe2O3)(0.98)(Ag0.97Ni0.03)(0.02). Magnetic and magnetomechanical properties were measured and the law of approach was used to model the effect of changing torsional stress on magnetization. In the model calculations an effective magnetic field due to the torsional stress was considered in order to calculate the anhysteretic magnetization, The change of amplitude and orientation of magnetization was determined by considering magnetoelastic, magnetostatic and anisotropic energies using a generalization of a model proposed by Garshelis. The measured and modeled results were in good agreement giving magnetomechanical sensitivities of 61 and 65 A/m per N.m, respectively. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Chen, Y (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 9 TC 8 Z9 10 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 3244 EP 3247 DI 10.1109/20.908755 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700345 ER PT J AU Sablik, MJ Jiles, DC AF Sablik, MJ Jiles, DC TI Modeling effects of varying torsion in magnetized steel SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE H sigma process; law of approach; magnetomechanical hysteresis modeling; torsional stress ID HYSTERESIS; STRESS AB In this paper, we develop a model for magnetization changes in a steel rod under varying torsion in a constant applied magnetic field, At any point on the surface of the rod under torsion, the magnetization changes, in a small region about the point, are driven by biaxial stress changes, which are equal in magnitude, with one stress change tensile and the other compressive, and with the stresses acting at +/-45 degrees with respect to the rod axis, tangentially to the surface of the rod, In this paper, we demonstrate how to extend the "law of approach" of and the energy balance equation to irreversible magnetization changes under varying torsional stress at constant magnetic field. As an illustration of how the model is used, a prediction is made showing changes in axial nux density at the surface of the rod when the torsion is cycled five times between zero and a maximum value of torque. C1 SW Res Inst, San Antonio, TX 78228 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Sablik, MJ (reprint author), SW Res Inst, 6220 Culebra Rd, San Antonio, TX 78228 USA. RI Jiles, David/H-9548-2012 NR 8 TC 1 Z9 1 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 3248 EP 3250 DI 10.1109/20.908756 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700346 ER PT J AU Bennett, LH Waterstrat, RM Swartzendruber, LJ Watson, RE AF Bennett, LH Waterstrat, RM Swartzendruber, LJ Watson, RE TI Structure and magnetism in the systems Zr-3(Rh1-xRux)(4) and Zr-3(Rh1-yPdy)(4) SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT International Magnetics Conference (INTERMAG 2000) CY APR 09-12, 2000 CL TORONTO, CANADA DE B2 structure; ferromagnetism; incommensurate waves; Pu3Pd4 structure; Zr-Rh-Pd; Zr-Rh-Ru systems ID FERROMAGNETISM AB The Zr-3(Rh(1-y)Pdy)(4) system in the Pu3Pd4 structure, reported on previously, is further investigated here, it exhibits an incommensurate density wave for 0.04 less than or equal to y less than or equal to 0.06, accompanied by strongly varying paramagnetism, It displays weak ferromagnetism at one composition and weak superconductivity at an other, Changes in cooperative behavior with such small changes in composition are unique for a metallic system, The present results indicate that there is a charge density wave of constant wave vector direction and varying lattice displacements in this composition range, with microcracks developing for y = 0.04. C1 George Washington Univ, Inst Magnet Res, Ashburn, VA 20147 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Bennett, LH (reprint author), George Washington Univ, Inst Magnet Res, Ashburn, VA 20147 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 2000 VL 36 IS 5 BP 3502 EP 3504 DI 10.1109/20.908874 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 409EN UT WOS:000167371700422 ER PT J AU Oliker, L Biswas, R AF Oliker, L Biswas, R TI Parallelization of a dynamic unstructured algorithm using three leading programming paradigms SO IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS LA English DT Article; Proceedings Paper CT 1999 Supercomputing Conference CY NOV 13-19, 1999 CL PORTLAND, OREGON DE distributed memory systems; CC-NUMA machines; multithreaded architectures; parallel implementation techniques; application performance studies; unstructured mesh adaptation AB The success of parallel computing in solving real-life computationally intensive problems relies on their efficient mapping and execution on large-scale multiprocessor architectures. Many important applications are both unstructured and dynamic in nature, making their efficient parallel implementation a daunting task. This paper presents the parallelization of a dynamic unstructured mesh adaptation algorithm using three popular programming paradigms on three leading supercomputers. We examine an MPI message-passing implementation on the Gray T3E and the SGI Origin2000, a shared-memory implementation using the cache coherent nonuniform memory access (CC-NUMA) feature of the Origin2000, and a multithreaded version on the newly released Tera Multithreaded Architecture (MTA). We compare several critical factors of this parallel code development, including runtime, scalability, programmability, portability, and memory overhead. Our overall results demonstrate that multithreaded systems offer tremendous potential for quickly and efficiently solving some of the most challenging real-life problems on parallel computers. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. NASA, Comp Sci Corp, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Oliker, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, MS 50F, Berkeley, CA 94720 USA. NR 10 TC 18 Z9 18 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 1045-9219 J9 IEEE T PARALL DISTR JI IEEE Trans. Parallel Distrib. Syst. PD SEP PY 2000 VL 11 IS 9 BP 931 EP 940 DI 10.1109/71.879776 PG 10 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 368VA UT WOS:000090137100006 ER PT J AU Cong, G Parvin, B AF Cong, G Parvin, B TI Shape recovery from equal thickness contours SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article DE shape-from-X; 3D construction; shape from multiple views ID SATELLITE RADAR INTERFEROMETRY; PHASE-UNWRAPPING TECHNIQUES; RECONSTRUCTION AB A unique imaging modality based on Equal Thickness Contours (ETC) has introduced a new opportunity far 3D shape reconstruction from multiple views. These ETCs can be generated through an interference between transmitted and diffracted beams. We present a computational framework for representing each view of an object in terms of its object thickness and then integrating these representations into a 3D surface by algebraic reconstruction. In this framework, the object thickness is first derived from ideal contours and then extended to real data. For real data, the object thickness is inferred by grouping curve segments that correspond to points of second derivative maxima. At each step of the process, we use some form of regularization to ensure closeness to the original features as well as neighborhood continuity. We apply our approach to images of a submicron crystal structure obtained through a holographic process. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, MS 50B-2239,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM gcong@media.lbl.gov; parvin@media.lbl.gov NR 22 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0162-8828 EI 1939-3539 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD SEP PY 2000 VL 22 IS 9 BP 1055 EP 1061 DI 10.1109/34.877527 PG 7 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 361TY UT WOS:000089741300012 ER PT J AU Douglas, GC McNamara, J AF Douglas, GC McNamara, J TI Shoot regeneration from seedling explants of Acacia mangium Willd SO IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY-PLANT LA English DT Article DE Acacia mangium; adventitious shoots; morphogenesis; regeneration ID PLANTLETS; CULTURES; TREE AB Regeneration of adventitious shoots was obtained in over 80% of explants, consisting of wounded cotyledonary nodes of Acacia mangium, by culturing germinated seedlings on DKW medium with combinations of N-6-benzyladenine and either thidiazuron or N-(2-chloro-4-pyridyl)-N-phenylurea. Electron micrscopy showed the presence of adventitious buds arising from wound tissue of the cotyledons and cotyledonary nodes. Shoot regeneration was also obtained at lower frequency in isolated cotyledon explants cultured with 6% sucrose alone (10%), or with 3% sucose and 30.0 mg l(-1) (0.1 muM) 2-4-dichlorophenoxyacetic acid (2,4-D; 16%). With 2,4-D, >60% of explants produced organized structures but these did not develop into shoots or somatic embryos. Shoot formation was not induced in either hypocotyl or root explants. C1 TEAGASC, Agr & Food Dev Author, Kinsealy Res Ctr, Dublin 17, Ireland. RP Douglas, GC (reprint author), TEAGASC, Agr & Food Dev Author, Kinsealy Res Ctr, Malhide Rd, Dublin 17, Ireland. EM gdouglas@kinsealy.teagasc.ie NR 18 TC 5 Z9 5 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1054-5476 EI 1475-2689 J9 IN VITRO CELL DEV-PL JI In Vitro Cell. Dev. Biol.-Plant PD SEP-OCT PY 2000 VL 36 IS 5 BP 412 EP 415 PG 4 WC Plant Sciences; Cell Biology; Developmental Biology SC Plant Sciences; Cell Biology; Developmental Biology GA 397RM UT WOS:000166709400020 ER PT J AU Hodgson, AT Rudd, AF Beal, D Chandra, S AF Hodgson, AT Rudd, AF Beal, D Chandra, S TI Volatile organic compound concentrations and emission rates in new manufactured and site-built houses SO INDOOR AIR-INTERNATIONAL JOURNAL OF INDOOR AIR QUALITY AND CLIMATE LA English DT Article DE houses; ventilation; formaldehyde; aldehydes; VOC; emissions ID INDOOR AIR; MOBILE HOMES; FORMALDEHYDE; PRODUCTS; EXPOSURE AB Concentrations of 54 volatile organic compounds (VOCs) and ventilation rates were measured in four new manufactured houses over 2-9.5 months following installation and in seven new site-built houses 1-2 months after completion. The houses were in four projects located in hot-humid and mixed-humid climates. They were finished and operational, but unoccupied. Ventilation rates ranged from 0.14-0.78 h(-1). Several of the site-built houses had ventilation rates below the ASHRAE recommended value. In both manufactured and site-built houses, the predominant airborne compounds were alpha-pinene, formaldehyde, hexanal, and acetic acid. Formaldehyde concentrations were below or near 50 ppb with a geometric mean value for all houses of 40 ppb. Similarities in the types of VOCs and in VOC concentrations indicated that indoor air quality in the houses was impacted by the same or similar sources. Major identified sources included plywood flooring, latex paint and sheet vinyl flooring. One site-built house was operated at ventilation rates of 0.14 and 0.32 h(-1). VOC emission rates calculated at the two conditions agreed within +/-10% for the most volatile compounds. Generally, the ratios of emission rates at the low and high ventilation rates decreased with decreasing compound volatility. Changes in VOC emission rates in the manufactured houses over 2-9.5 months after installation varied by compound. Only several compounds showed a consistent decrease in emission rate over this period. C1 EO Lawrence Berkeley Natl Lab, Environm & Energy Technol Div, Indoor Environm Dept, Berkeley, CA 94720 USA. Florida Solar Energy Ctr, Cocoa, FL USA. RP Hodgson, AT (reprint author), EO Lawrence Berkeley Natl Lab, Environm & Energy Technol Div, Indoor Environm Dept, Berkeley, CA 94720 USA. NR 34 TC 122 Z9 132 U1 6 U2 39 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0905-6947 J9 INDOOR AIR JI Indoor Air-Int. J. Indoor Air Qual. Clim. PD SEP PY 2000 VL 10 IS 3 BP 178 EP 192 DI 10.1034/j.1600-0668.2000.010003178.x PG 15 WC Construction & Building Technology; Engineering, Environmental; Public, Environmental & Occupational Health SC Construction & Building Technology; Engineering; Public, Environmental & Occupational Health GA 348FU UT WOS:000088975500006 PM 10979199 ER PT J AU Bond, AH Rogers, RD Dietz, ML AF Bond, AH Rogers, RD Dietz, ML TI Nuclear separations for radiopharmacy: The need for improved separations to meet future research and clinical demands SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID GENERATORS; RADIONUCLIDES; TECHNETIUM; CHEMISTRY; MEDICINE; MO-99 AB Several recent national and international reports have predicted that the demand for radionuclides used in medicine will increase significantly over the next 20 years. Separation science is an integral part of the production and development of new radionuclides for diagnostic and therapeutic applications and will play a major role in process improvements to existing radiopharmaceuticals to meet increasing demands. The role of separation science in the production of radionuclides for medical applications is briefly discussed, followed by an overview of the manuscripts from the American Chemical Society symposium "Nuclear Separations for Radiopharmacy". A Listing of the most widely used radionuclides in clinical application and medical research serves as a foundation for the discussion of future research opportunities in separation science. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. RP Bond, AH (reprint author), PG Res Fdn Inc, 8205 S Cass Ave,Suite 111, Darien, IL 60561 USA. NR 40 TC 1 Z9 1 U1 1 U2 1 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 SEP PY 2000 VL 39 IS 9 BP 3130 EP 3134 DI 10.1021/ie990765j PG 5 WC Engineering, Chemical SC Engineering GA 352JF UT WOS:000089211200002 ER PT J AU Whitlock, JL Roeske, JC Dietz, ML Straus, CM Hines, JJ Horwitz, EP Reba, RC Rotmensch, J AF Whitlock, JL Roeske, JC Dietz, ML Straus, CM Hines, JJ Horwitz, EP Reba, RC Rotmensch, J TI Radionuclide therapy for the treatment of microscopic ovarian carcinoma: An overview SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID IN-VITRO; RA-224; BI-212; DNA AB Cancer comprises a group of diseases characterized by the uncontrolled growth of abnormal cells that spread from the anatomical site of origin. For many types of cancer, surgery alone has proven inadequate, necessitating a broader approach to treatment incorporating chemotherapy and radiotherapy. Of particular recent interest has been the use of alpha-emitters in the treatment of microscopic carcinoma. The effective application of these materials requires an understanding of the physical and biological bases of radiation therapy. In addition, both radiochemical and radionuclidic purity are essential in all clinical applications. Recent work with the alpha-emitting radionuclide bismuth-212 offers considerable promise in the treatment of microscopic ovarian carcinoma resistant to conventional treatment modalities. Ongoing improvements in methods for its preparation are expected to further improve its therapeutic utility. C1 Univ Chicago, Dept Obstet, Chicago, IL 60637 USA. Univ Chicago, Dept Gynecol, Sect Oncol Radiat & Cellular Oncol, Chicago, IL 60637 USA. Univ Chicago, Dept Radiol, Chicago, IL 60637 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Whitlock, JL (reprint author), Univ Chicago, Dept Obstet & Gynecol, Sect Oncol, Chicago, IL 60637 USA. NR 28 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 SEP PY 2000 VL 39 IS 9 BP 3135 EP 3139 DI 10.1021/ie000425u PG 5 WC Engineering, Chemical SC Engineering GA 352JF UT WOS:000089211200003 ER PT J AU Vandegrift, GF Conner, C Hofman, GL Leonard, RA Mutalib, A Sedlet, J Walker, DE Wiencek, TC Snelgrove, JL AF Vandegrift, GF Conner, C Hofman, GL Leonard, RA Mutalib, A Sedlet, J Walker, DE Wiencek, TC Snelgrove, JL TI Modification of targets and processes for conversion of Mo-99 production from high- to low-enriched uranium SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB As part of the U.S. nonproliferation effort, Ne are investigating the conversion of the production of fission-product Mo-99 from use of high-enriched uranium (HEU) to low-enriched uranium (LEU). Successful conversion from HEU to LEU (<20% U-235) requires an irradiation target that contains 5 times more uranium but minimizes changes to target geometry and processing. The LEU target being developed uses thin foils of uranium metal that can be removed from the target hardware for dissolution and processing. This paper describes our recent successes in target fabrication, irradiation, and processing. Target fabrication has been improved by (1) heat-treating the uranium foil to produce a random, small-grain structure and (2) electrodepositing zinc and nickel fission-fragment barriers onto the foil. These fission-fragment barriers have been found to be stable during transport of the targets following irradiation. Recent irradiation tests have shown that the concept is sound. Progress was also made in broadening international cooperation in our development activities. C1 Argonne Natl Lab, Reduced Enrichment Res & Test Reactor Program, Argonne, IL 60439 USA. RP Vandegrift, GF (reprint author), Argonne Natl Lab, Reduced Enrichment Res & Test Reactor Program, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 26 TC 10 Z9 10 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD SEP PY 2000 VL 39 IS 9 BP 3140 EP 3145 DI 10.1021/ie9905815 PG 6 WC Engineering, Chemical SC Engineering GA 352JF UT WOS:000089211200004 ER PT J AU McDonald, MJ Carson, SD Naranjo, GE Wemple, JA AF McDonald, MJ Carson, SD Naranjo, GE Wemple, JA TI Challenges of extracting and purifying fission-produced molybdenum-99 SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB Sandia National Laboratories (SNL) has produced limited quantities of fission-produced molybdenum-99 (Mo-99) within industry purity specifications using the Cintichem production process. Molybdenum-99 is produced by the irradiation of a target which has an electrochemically deposited layer of enriched uranium oxide. The Cintichem processing method involves the dissolving the uranium coating from the target, chemically extracting the Mo-99 from the ther fission products, and purifying the product by column chromatography. The chemical extraction and purification of Mo-99 was performed using remote manipulators in the SNL Hot Cell Facility (HCF). To thoroughly understand the production process, two series of tests were designed: the first was a series of cold tests using 20 g samples of a depleted or low-irradiated uranium dioxide (UO2) powder and the second was conducted using irradiated targets coated with similar to 25 g of enriched uranium oxide. In addition, testing of radiation effects was performed at the SNL Gamma Irradiation Facility on chemicals and hardware used in the processing to evaluate the degradation due to the high radiation field expected during the chemical separation. Unique production hardware, fixtures, and tools were developed to facilitate remote processing of irradiated targets at the HCF. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP McDonald, MJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 8 Z9 8 U1 2 U2 10 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 SEP PY 2000 VL 39 IS 9 BP 3146 EP 3150 DI 10.1021/ie990377h PG 5 WC Engineering, Chemical SC Engineering GA 352JF UT WOS:000089211200005 ER PT J AU Carson, SD Tallant, DR McDonald, MJ Garcia, MJ Simpson, RL AF Carson, SD Tallant, DR McDonald, MJ Garcia, MJ Simpson, RL TI Radiation chemistry of simulated Mo-99 product SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID RAMAN-SPECTROSCOPY; MOO3 AB Pharmaceutical houses that produce Tc-99m/Tc-99 generators have on occasion received product solutions of Mo-99 produced from U-235 fission that contained a black precipitate. Addition of sodium hypochlorite to product bottles prior to shipment prevents precipitate formation, which is evidence that the precipitate is most likely a reduced farm of Mo. The radiation effects of the dose from Mo-99 on the product and product bottle have been determined by irradiating simulated Mo-99 product solutions with the Co-60 source at Sandia National Laboratories' Gamma Irradiation Facility (GIF). The GIF experiment successfully generated a black precipitate in amounts sufficient for isolation and analysis by infrared and Raman spectroscopy. Changes in the pH of the basic Mo-99 product solution during irradiation were monitored by titration. Results of these analyses and the nature of the process that generates the precipitate, a mixture of molybdenum oxides that forms in plastic bottles but not in glass containers, are discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Carson, SD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 15 TC 0 Z9 0 U1 0 U2 3 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 SEP PY 2000 VL 39 IS 9 BP 3151 EP 3156 DI 10.1021/ie990378+ PG 6 WC Engineering, Chemical SC Engineering GA 352JF UT WOS:000089211200006 ER PT J AU Christian, JD Petti, DA Kirkham, RJ Bennett, RG AF Christian, JD Petti, DA Kirkham, RJ Bennett, RG TI Advances in sublimation separation of technetium from low-specific-activity molybdenum-99 SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID TARGETS; OXIDE AB Two sublimation techniques have been developed to separate Tc from Mo to support accelerator production of Mo-99/Tc-99m. After bombardment, the metal target is dissolved in nitric acid, the solution is evaporated, and the precipitated solids are calcined to MoO3. In the first technique, MoO3 is melted to a 0.8 mm layer and oxygen is swept over the 835 degrees C sample at 30 std cm(3)/min. Small amounts of MoO3 vapors transported from the 835 degrees C sample are deposited above 550 degrees C onto the walls of a quartz tube in a temperature gradient of 4 degrees C/cm. Greater than 95% of released technetium oxide is collected in a 5 mL condenser at temperatures between 300 and 25 degrees C. In the second process, technetium oxide deposited on the surface of fine needle crystals of MoO3 is quantitatively released in an oxygen stream at 650 degrees C. The crystals are regenerated between milkings by dissolving in NH4OH, evaporating, and drying. In this initial work, greater than 90% product recovery is achieved by both processes during multiple milkings of 14 g Mo samples and a high-purity Tc-99m product results at a concentration exceeding 500 mCi/mL in an isotonic saline solution. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Christian, JD (reprint author), Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 34 TC 12 Z9 13 U1 1 U2 4 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 SEP PY 2000 VL 39 IS 9 BP 3157 EP 3168 DI 10.1021/ie9903792 PG 12 WC Engineering, Chemical SC Engineering GA 352JF UT WOS:000089211200007 ER PT J AU Mirzadeh, S Du, MT Beets, A Knapp, FF AF Mirzadeh, S Du, MT Beets, A Knapp, FF TI Thermoseparation of neutron-irradiated tungsten from Re and Os SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID GENERATOR; RADIOPHARMACEUTICALS AB Heterogeneous oxidation has been utilized for one-step conversion of metallic W to WO3 at similar to 750 degrees C in a stream of air, with simultaneous separation of W from Re and Os impurities which are coproduced during the long neutron irradiation of the W target (similar to 50 days). The freshly produced WO3 is readily soluble in a base for use in a W-188/Re-188 biomedical generator. The metallic tungsten target, in the form of small pellets (4 x 3 mm diameter x height), was prepared by cold pressing W powder at similar to 3 tons/cm(2). Sintering (vacuum annealing) the pellets at 1200-1400 degrees C, under 1-10 mu Torr pressure provided good mechanical strength. Analysis of the black residue, which is typically encountered in the dissolution of neutron-irradiated WO3 targets, indicated that W-186 and Re-187 were the main constituents. Further, the specific activity of insoluble W-188 in the residue was similar to 200 times smaller than that of soluble W-188. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Mirzadeh, S (reprint author), Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. NR 13 TC 3 Z9 3 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 SEP PY 2000 VL 39 IS 9 BP 3169 EP 3172 DI 10.1021/ie990582x PG 4 WC Engineering, Chemical SC Engineering GA 352JF UT WOS:000089211200008 ER PT J AU Dietz, ML Horwitz, EP AF Dietz, ML Horwitz, EP TI Applications of extraction chromatography in the development of radionuclide generator systems for nuclear medicine SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID SOLVENT-IMPREGNATED RESINS; CHELATE-FORMING RESIN; ANION-EXCHANGER; TRUEX PROCESS; CROWN-ETHER; SEPARATION; PRECONCENTRATION; ACTINIDES; WASTE; ACID AB Numerous methods have been described for the separation and purification of radionuclides for application in diagnostic and therapeutic nuclear medicine, among them ion exchange, solvent extraction, and various forms of chromatography. Although extraction chromatography has previously been shown to provide a means of performing a number of separations of potential use in radionuclide generator systems, the application of the technique to generator development has thus far been limited. Recent work directed at improved methods for the determination of radionuclides in biological and environmental samples has led to the development of a series of novel extraction chromatographic resins exhibiting enhanced metal ion retention from strongly acidic media and excellent selectivity, among them materials suitable for the isolation of Bi-212, Y-90, and Bi-213. These resins, along with extraction chromatographic materials employing functionalized supports to improve their physical stability or metal ion retention properties, are shown to offer promise in the development of improved radionuclide generators. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Dietz, ML (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 52 TC 9 Z9 10 U1 1 U2 5 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 SEP PY 2000 VL 39 IS 9 BP 3181 EP 3188 DI 10.1021/ie9903745 PG 8 WC Engineering, Chemical SC Engineering GA 352JF UT WOS:000089211200010 ER PT J AU Bray, LA Tingey, JM DesChane, JR Egorov, OB Tenforde, TS Wilbur, DS Hamlin, DK Pathare, PM AF Bray, LA Tingey, JM DesChane, JR Egorov, OB Tenforde, TS Wilbur, DS Hamlin, DK Pathare, PM TI Development of a unique bismuth (Bi-213) automated generator for use in cancer therapy SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID AC-225 AB A unique separations chemistry and an automated "generator" have been developed for application of the alpha-emitting radionuclide Bi-213 to cancer therapy. The generator was developed for separation of the short-lived Bi-213 (t(1/2) = 45.6 min) from the parent radionuclide Ac-225 (t(1/2) = 10 days), which is separated from Th-229 (t1/2 = 7340 yr) and its daughter isotope Ra-225 (t(1/2) = 14.8 days). The generator requires purified Ac-225 and uses organic anion-exchange system capable of isolating Bi-213 from a HCl solution of Ac-225. Th, anion resin is then washed and stripped of the Bi product using a sodium acetate buffer. This allows direct attachment of Bi-213 to modified monoclonal antibodies and other targeting agents for use in patient treatment of cancers such as leukemia. To permit safe and rapid isolation of Bi-213 in 1 to > 20 mCi quantities, an automated system using sequential flow injection was developed. Successful evaluation of the labeling efficiency of proteins was completed using the separated Bi product. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Washington, Dept Radiat Oncol, Seattle, WA 98195 USA. RP Bray, LA (reprint author), Pacific NW Natl Lab, POB 999 P7-25, Richland, WA 99352 USA. NR 18 TC 6 Z9 6 U1 0 U2 1 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 SEP PY 2000 VL 39 IS 9 BP 3189 EP 3194 DI 10.1021/ie990068r PG 6 WC Engineering, Chemical SC Engineering GA 352JF UT WOS:000089211200011 ER PT J AU Deevi, SC Liu, CT Yamaguchi, M AF Deevi, SC Liu, CT Yamaguchi, M TI Intermetallics for the Third Millennium: A Symposium Dedicated to Professor R.W. Cahn 1-4 November 1999, Cincinnati, OH, USA - Preface SO INTERMETALLICS LA English DT Editorial Material C1 Chrysalis Technol Inc, Richmond, VA USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Kyoto Univ, Kyoto, Japan. RP Deevi, SC (reprint author), Chrysalis Technol Inc, Richmond, VA USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 969 EP 969 PG 1 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700001 ER PT J AU Prasad, YVRK Sasidhara, S Sikka, VK AF Prasad, YVRK Sasidhara, S Sikka, VK TI Characterization of mechanisms of hot deformation of as-cast nickel aluminide alloy SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OHIO SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE nickel aluminides, based on Ni3Al; deformation map; plastic forming, hot; microstructure ID ORDER-DISORDER TRANSFORMATION; NI3AL-FE ALLOYS; SINGLE-CRYSTALS; BEHAVIOR; STRESS AB The hot deformation behavior of as-cast Ni3Al alloy has been characterized on the basis of its flow stress variation obtained by isothermal constant true strain rate compression testing in the temperature range 1100-1250 degreesC and strain rate range 0.001-10 s(-1) The mechanisms of hot working have been evaluated using four generations of materials modeling techniques, which included shape of stress-strain curves, kinetic analysis, processing maps and dynamical systems approach. The material exhibited a steady-state flow behavior at slower strain rates but flow softening associated sometimes with broad oscillations, was observed at higher strain rates. The flow stress data did not obey the kinetic rate equation over the entire regime of testing but a good fit has been obtained in the intermediate range of temperatures (1150-1200 degreesC). In this range, a stress exponent Value of 6.5 and an apparent activation energy of about 750 kJ/mol have been evaluated. Microstructural investigations have shown that the matrix gamma' phase undergoes dynamic recovery in the presence of harder gamma colonies The processing maps revealed four different domains out of which three are interpreted to represent cracking processes. The fourth domain, which has a peak efficiency of about 44%, occurred at 1250 degreesC/0.001 s(-1). Microstructural observations revealed that this domain represents dynamic recrystallization (DRX) of gamma phase and is desirable for hot working the material. The material exhibits flow instabilities when deformed in the intermediate temperature regime at strain rates higher than 1 s(-1) and these are manifested as shear localization. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Indian Inst Sci, Dept Met, Bangalore 560012, Karnataka, India. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Prasad, YVRK (reprint author), Indian Inst Sci, Dept Met, Bangalore 560012, Karnataka, India. NR 18 TC 41 Z9 43 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 987 EP 995 DI 10.1016/S0966-9795(00)00048-0 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700006 ER PT J AU Misra, A Gibala, R AF Misra, A Gibala, R TI Plasticity in multiphase intermetallics SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OHIO SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE multiphase intermetallics; nicker aluminides, based on NiAl ID TEMPERATURE DEFORMATION-BEHAVIOR; SOLIDIFIED NIAL-MO; MECHANICAL-PROPERTIES; FRACTURE-BEHAVIOR; SINGLE-CRYSTALS; ALLOYS; COMPOSITES; TENSILE; PHASE; ALUMINIDES AB We have studied the mechanical behavior of model NiAl-based eutectic composites to gain insight on micromechanisms of plasticity in multiphase intermetallics. We show that in composites where the NiAl matrix and the reinforcing ductile second phase can deform compatibly due to easy slip transfer across interfaces, high room temperature tensile ductility and fracture toughness are obtained. In composites where interfaces are strong barriers to slip transfer and the metallic second phase has high strength and limited ductility, incompatible deformation of the two phases results in negligible tensile ductility and limited toughness enhance ment. Factors that affect ease of slip transfer across interfaces are discussed. Calculations of dislocation pile-up stresses are used to predict whether slip is activated prior to cleavage or vice-versa for a given set of respective yield strengths and crystallographic orientation relationships between the two phases. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. RP Misra, A (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MS K765, Los Alamos, NM 87545 USA. RI Misra, Amit/H-1087-2012 NR 37 TC 67 Z9 69 U1 0 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 1025 EP 1034 DI 10.1016/S0966-9795(00)00079-0 PG 10 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700011 ER PT J AU Brady, MP Zhu, JH Liu, CT Tortorelli, PF Walker, LR AF Brady, MP Zhu, JH Liu, CT Tortorelli, PF Walker, LR TI Oxidation resistance and mechanical properties of Laves phase reinforced Cr in-situ composites SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OH SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE laves phases; multiphase intermetallics; environmental embrittlement; fracture toughness; oxidation ID MICROSTRUCTURE; ALLOYS; BEHAVIOR AB Two-phase Cr(X)-Cr(2)X (X= Nb, Ta) in-situ composites are of interest for high-temperature applications due to their high melting points and potential for high-temperature strength. A six cycle, 120 h, 1100 degreesC cyclic oxidation screening test was used to evaluate potential for high-temperature oxidation resistance of several Cr(X)-Cr(2)X in-situ composites. Alloys based on the Cr-Ta system near the Cr(Ta)-Cr(2)Ta eutectic exhibited superior oxidation resistance compared to corresponding alloys based on the Cr-Nb system. The binary Cr-Ta alloys were also found to exhibit a moderate degree of room-temperature fracture toughness, in the range of 9-10 MPa rootm. It was concluded that the Cr(Ta)-Cr(2)Ta alloys are a promising base for future high-temperature intermetallic alloy development efforts. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Brady, MP (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM bradymp@ornl.gov RI Brady, Michael/A-8122-2008; Tortorelli, Peter/E-2433-2011; OI Brady, Michael/0000-0003-1338-4747; Liu, Chain Tsuan/0000-0001-7888-9725 NR 28 TC 29 Z9 37 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 1111 EP 1118 DI 10.1016/S0966-9795(00)00046-7 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700021 ER PT J AU Liu, CT Zhu, JH Brady, MP McKamey, CG Pike, LM AF Liu, CT Zhu, JH Brady, MP McKamey, CG Pike, LM TI Physical metallurgy and mechanical properties of transition-metal Laves phase alloys SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OH SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE Laves phases; mechanical properties at high temperatures; mechanical properties at ambient temperature; defects : point defects ID INTERMETALLIC COMPOUNDS; THERMAL-STRESSES; POINT-DEFECTS; CR-CR2NB; MICROSTRUCTURE; HYDROGEN; COMPOSITES; BEHAVIOR AB This paper provides a comprehensive review of the recent research on the phase stability, point defects, and fracture toughness of AB(2) Laves phases, and on the alloy design of dual-phase alloys based on a soft Cr solid solution reinforced with hard XCr2 second phases (where X=Nb, Ta and Zr). Anti-site defects were detected on both sides of the stoichiometric composition of NbCr2, NbCo2, and NbFe2, while they were observed only on the Co-rich side of ZrCo2. Only thermal vacancies were detected in the Laves phase alloys quenched from high temperatures. The room-temperature fracture toughness cannot be effectively improved by increasing thermal vacancy or reducing stacking fault energy through control of phase stability. Microstructures, mechanical properties, and oxidation resistance of dual-phase alloys based on Cr-NbCr2, Cr-TaCr2, and Cr-ZrCr2 were studied as functions of heat treatment and test temperature at temperatures to 1200 degreesC. Among the three alloy systems, Cr-TaCr2 alloys possess the best combination of mechanical and metallurgical properties for structural use at elevated temperatures. (C) 2000 Published by Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Liu, CT (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Brady, Michael/A-8122-2008; OI Brady, Michael/0000-0003-1338-4747; Liu, Chain Tsuan/0000-0001-7888-9725 NR 50 TC 124 Z9 141 U1 5 U2 21 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 EI 1879-0216 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 1119 EP 1129 DI 10.1016/S0966-9795(00)00109-6 PG 11 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700022 ER PT J AU Natesan, K Deevi, SC AF Natesan, K Deevi, SC TI Oxidation behavior of molybdenum silicides and their composites SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OH SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE molybdenum silicides; composites; oxidation; phase identification; hot isostatic pressing; electron microscopy, scanning ID HIGH-TEMPERATURE OXIDATION; DISILICIDE; CREEP AB A key materials issue associated with the future of high-temperature structural silicides is the resistance of these materials to oxidation at low temperatures. Oxidation tests were conducted on Mo-based silicides over a wide temperature range to evaluate the effects of alloy composition and temperature on the protective scaring characteristics and pesting regime for the materials. The study included Mo5Si3 alloys that contained several concentrations of B. In addition, oxidation characteristics of MOSi2-Si3N4 composites that contained 20-80 vol.% Si3N4 were evaluated at 500-1400 degreesC. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Chrysalis Technol Inc, Richmond, VA 23234 USA. RP Natesan, K (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. EM natesan@anl.gov NR 26 TC 69 Z9 76 U1 2 U2 15 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 EI 1879-0216 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 1147 EP 1158 DI 10.1016/S0966-9795(00)00060-1 PG 12 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700024 ER PT J AU Summers, E Thom, AJ Cook, B Akinc, M AF Summers, E Thom, AJ Cook, B Akinc, M TI Extrusion and selected engineering properties of Mo-Si-B intermetallics SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OHIO SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE intermetallics, miscellaneous; molybdenum silicides; extrusion ID ISOTHERMAL OXIDATION BEHAVIOR; SILICIDES; MO5SI3; CREEP; BORON AB In this study, an extrusion process has been developed to produce defect free, high-density rods of Mo-Si-B material. An initial powder composition (53.5 vol.%, 91 wt.%) of 66 vol.% Mo5Si3Bx (T1)-16 vol.% MdB-18 vol.% MoSi2 was mixed with a paraffin-wax based binder (46.5 vol.%, 9 wt.%) and extruded using a twin-screw extruder. Following binder removal by a combination process of wicking and thermal degradation, the material was sintered at 1800 degreesC. The bulk density of the sintered material was 90-92% of theoretical. Thorough binder removal was evidenced by low impurity levels. 258+/-6 ppm carbon and 772+/-10 ppm oxygen. The material demonstrated excellent high temperature oxidation resistance. The calculated parabolic rate constant is 1.1 x 10(-2) mg(2)/cm(4)/h at 1600 degreesC. The extruded material was also successfully tested as a resistance heating element. These materials show promise for the development of heating elements with enhanced performance compared to current MoSi2-based heating elements. (C) 2000 Published by Elsevier Science Ltd. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Thom, AJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 13 TC 18 Z9 19 U1 2 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 1169 EP 1174 DI 10.1016/S0966-9795(00)00080-7 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700026 ER PT J AU Petrovic, JJ AF Petrovic, JJ TI Toughening strategies for MoSi2-based high temperature structural silicides SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OHIO SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE molybdenum silicides; alloy design; brittleness and ductility; fracture toughness; mechanical properties at ambient temperature ID MECHANICAL-PROPERTIES; PLASTIC-DEFORMATION; ALUMINUM ADDITIONS; MOSI2 COMPOSITES; SINGLE-CRYSTALS; MICROSTRUCTURE; TOUGHNESS AB The key materials issue associated with the future of high temperature structural silicides is the improvement in the low temperature fracture toughness of these materials. Many industrial applications require materials with fracture toughness levels in the vicinity of 10 MPa m(1/2), while turbine applications require toughness levels of 15 MPa m(1/2) or higher. Two important routes currently being pursued to increase silicide fracture toughness are the composite approach and the alloying approach. Composites based on the reinforcement of MoSi2 with ceramics are discussed. Alloying approaches for MoSi2 based on limited theoretical guidance are outlined. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Petrovic, JJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 34 TC 93 Z9 120 U1 3 U2 12 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 1175 EP 1182 DI 10.1016/S0966-9795(00)00044-3 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700027 ER PT J AU Yoo, MH Yoshimi, K AF Yoo, MH Yoshimi, K TI An empirical model for ideal work of adhesion: transition-metal aluminides and silicides SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OH SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE aluminides, miscellaneous; silicides, various; anisotropy; fracture stress; physical properties, miscellaneous ID CLEAVAGE FRACTURE; TITANIUM ALUMINIDES; ELASTIC-CONSTANTS; ENERGY; SURFACES; BEHAVIOR; ALLOYS; DEFORMATION; SOLIDS; AL3SC AB The role of atomic bonding in the brittle fracture of intermetallic alloys has been assessed theoretically. A simple empirical model is proposed for the ideal work of adhesion, resulting from a rigid-body separation, in terms of four variables, viz. the elastic stiffness constant, the equilibrium interplanar spacing, and two scaling length parameters. The ratio of these two length parameters is assessed based on the available results of ab initio slab-supercell calculations. Ideal cleavage energies and critical stress intensity factors of transition-metal aluminides and silicides are estimated, and the results are discussed by comparing with the available experimental data of brittle fracture. The difference between the proposed model and other models, temperature dependence of surface energies, and an extension of this model for interfacial adhesion are also discussed. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Yoo, MH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. EM yoo@ornl.gov NR 55 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 EI 1879-0216 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 1215 EP 1224 DI 10.1016/S0966-9795(00)00082-0 PG 10 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700031 ER PT J AU Stoloff, NS Liu, CT Deevi, SC AF Stoloff, NS Liu, CT Deevi, SC TI Emerging applications of intermetallics SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OHIO SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE iron aluminides (based on Fe3Al); magnetic intermetallics; nickel aluminides, based on Ni3Al; molybdenum silicides; superplastic behavior ID COMPOSITES; ALLOYS; BORON; ALUMINIDES; SILICIDES; FRACTURE; CREEP AB Many intermetallic compounds display an attractive combination of physical and mechanical properties, including high melting point, low density and good oxidation or corrosion resistance. This has led to their utilization in many non-structural applications, but success in structural applications has, to date, been limited. This paper reviews the current status of intermetallic applications, with emphasis on new uses that are in place or pending. Most of the paper deals with aluminides and silicides, but there are several more complex intermetallics that are being employed in battery and magnetic applications. Research on improved processing and studies:of the role of environment in mechanical behavior are shown to be key to developing practical alloys. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Rensselaer Polytech Inst, Dept Mat Sci & Engn, Troy, NY 12180 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37380 USA. Philip Morris Inc, Res Ctr, Richmond, VA 23234 USA. RP Stoloff, NS (reprint author), Rensselaer Polytech Inst, Dept Mat Sci & Engn, 110 8th St, Troy, NY 12180 USA. OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 36 TC 314 Z9 333 U1 4 U2 59 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 1313 EP 1320 DI 10.1016/S0966-9795(00)00077-7 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700039 ER PT J AU Sikka, VK Deevi, SC Viswanathan, S Swindeman, RW Santella, ML AF Sikka, VK Deevi, SC Viswanathan, S Swindeman, RW Santella, ML TI Advances in processing of Ni3Al-based intermetallics and applications SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OHIO SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE nickel aluminides, based on Ni3Al; mechanical properties of high temperatures; casting; corrosion- and erosion-resistant applications; furnace furniture, including heating elements ID ALUMINIDES; NICKEL AB The intermetallic-based alloys for structural applications have been an active field of research around the world for the last 20 years. Several major breakthroughs have occurred in this field during this time period. These breakthroughs include: (I) the dramatic effects of boron on ductility improvement for Ni3Al at ambient and high temperatures, (2) effect of chromium addition for intermediate temperature ductility improvement of Ni3Al, and (3) identification of an environmental effect from hydrogen generated by the reduction of moisture in air by aluminum in the aluminides. The knowledge of the compositional effects has led to the development of Ni3Al-based alloys, which allowed them to be taken from laboratory-size melts to commercial applications. This paper will describe the advances in melting practice, casting practices, solidification modeling as it applies to static and centrifugal castings and weld repairs, and welding of castings. This paper will also describe various applications of Ni3Al-based alloys and their current status of commercialization. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Philip Morris Inc, Ctr Res Dev & Engn, Richmond, VA 23234 USA. RP Sikka, VK (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 34 TC 113 Z9 119 U1 1 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 1329 EP 1337 DI 10.1016/S0966-9795(00)00078-9 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700041 ER PT J AU Judkins, RR Rao, US AF Judkins, RR Rao, US TI Fossil energy applications of intermetallic alloys SO INTERMETALLICS LA English DT Article; Proceedings Paper CT International Symposium on Intermetallics for the 3rd Millennium - A Symposium Dedicated to RW Cahn CY NOV 01-04, 1999 CL CINCINNATI, OHIO SP ASM Int, Intermetall Mat Comm Crit Technol Sector, US DOE DE iron aluminides (based on Fe3Al); laves phases; molybdenum silicides; dispersion strengthening; energy systems ID BORON; EMBRITTLEMENT; FE3AL AB This paper presents the history and results of the US Department of Energy, Office of Fossil Energy (FE), development effort on iron aluminide alloys and the status of research and development on ultrahigh temperature (well above 1000 degrees C) intermetallic alloys. The outstanding (perhaps unequaled) sulfidation resistance of iron aluminide alloys, based on the Fe3Al composition, was the basis for initiation of an exploratory project to determine whether improvement in mechanical properties of iron aluminide alloys could be achieved. This was a high-risk venture but with significant payoff if successful, because sulfidation was a critical problem for applications of alloys in coal gasification systems. The exploratory project, which was conducted at Oak Ridge National Laborator (ORNL), was successful, and the program was expanded in both scope and participation. Several other national laboratories, industrial research organizations, and universities were involved. Iron aluminide development is now quite mature. Some of the research has transferred to line programs leading to product that will be used in advanced fossil energy systems. The first product to be commercialized for fossil energ applications was a porous metal filter developed jointly by ORNL and Pall Corporation. In addition to th coal gasification application, these filters are also being used in combustion systems. Several other commercial products are being pursued. Additional exploratory projects on intermetallic alloys have been initiated. These are also high risk activities, but, as with the iron aluminides, the payoff potential is great. The intermetallic alloys presently being investigated include a Cr2Ta-strengthened chromium alloy and a boron-modified molybdenum silicid based on Mo5Si3 The challenges with these alloys are to modify them to provide acceptable mechanical properties, including ductility and toughness, and corrosion resistance to allow them to be used in structure applications such as gas turbines. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. US DOE, Fed Energy Technol Ctr, Pittsburgh, PA USA. RP Judkins, RR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 36 TC 27 Z9 27 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP-NOV PY 2000 VL 8 IS 9-11 SI SI BP 1347 EP 1354 DI 10.1016/S0966-9795(00)00110-2 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 381GJ UT WOS:000165753700043 ER PT J AU Kimmel, R Malladi, R Sochen, N AF Kimmel, R Malladi, R Sochen, N TI Images as embedded maps and minimal surfaces: Movies, color, texture, and volumetric medical images SO INTERNATIONAL JOURNAL OF COMPUTER VISION LA English DT Article DE scale-space; minimal surfaces; PDE based non-linear image diffusion; selective smoothing; color processing; texture enhancement; movies and volumetric medical data ID LOW-LEVEL VISION; ANISOTROPIC DIFFUSION; MEAN-CURVATURE; SHOCK FILTERS; ENHANCEMENT; REPRESENTATION; SEGMENTATION; RESTORATION; SIGNAL; MODEL AB We extend the geometric framework introduced in Sochen et al. (IEEE Trans. on Image Processing, 7(3):310-318, 1998) for image enhancement. We analyze and propose enhancement techniques that selectively smooth images while preserving either the multi-channel edges or the orientation-dependent texture features in them. Images are treated as manifolds in a feature-space. This geometrical interpretation lead to a general way for grey level, color, movies, volumetric medical data, and color-texture image enhancement. We first review our framework in which the Polyakov action from high-energy physics is used to develop a minimization procedure through a geometric flow for images. Here we show that the geometric flow, based on manifold volume minimization, yields a novel enhancement procedure for color images. We apply the geometric framework and the general Beltrami flow to feature-preserving denoising of images in various spaces. Next, we introduce a new method for color and texture enhancement. Motivated by Gabor's geometric image sharpening method (Gabor, Laboratory Investigation, 14(6):801-807, 1965), we present a geometric sharpening procedure for color images with texture. It is based on inverse diffusion across the multi-channel edge, and diffusion along the edge. C1 Technion Israel Inst Technol, Dept Comp Sci, IL-32000 Haifa, Israel. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Tel Aviv Univ, Sch Math Sci, Dept Appl Math, IL-69978 Tel Aviv, Israel. Technion Israel Inst Technol, Dept Elect Engn, IL-32000 Haifa, Israel. RP Technion Israel Inst Technol, Dept Comp Sci, IL-32000 Haifa, Israel. NR 60 TC 180 Z9 185 U1 2 U2 12 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0920-5691 EI 1573-1405 J9 INT J COMPUT VISION JI Int. J. Comput. Vis. PD SEP PY 2000 VL 39 IS 2 BP 111 EP 129 DI 10.1023/A:1008171026419 PG 19 WC Computer Science, Artificial Intelligence SC Computer Science GA 359FD UT WOS:000089600100004 ER PT J AU Zhu, JY Choi, MY Mulholland, GW Gritzo, LA AF Zhu, JY Choi, MY Mulholland, GW Gritzo, LA TI Measurement of soot optical properties in the near-infrared spectrum SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID VOLUME FRACTION; REFRACTIVE-INDEXES; DIFFUSION FLAMES; TEMPERATURE; OXIDATION AB The dimensionless extinction constant, K-e, was measured using the NIST Large Agglomerate Optics Facility (LAOF) for soot produced from acetylene and ethene flames. Measurements were performed simultaneously using light sources at 632.8 and 856 nm. The experiments at 856 nm represent the longest wavelength for which accurate extinction measurements have been performed for soot. The mean values of present measurements of K-e at 632.8 nm for the acetylene and ethene soot are 8.12 +/- 0.59 and 9.65 +/- 0.54, respectively. For acetylene, the mean Value of K-e measured at 856 nm was 8.83 +/- 0.69, whereas the mean value for ethene at the same wavelength was 9.35 +/- 0.51. The reduction in discrepancy for the fuels between 632.8 and 856 nm may be related to beam shielding effects. As in the case of 632.8 nm, the measured K-e values for 856 nm are significantly larger than values calculated using traditional methods. The present measurements provide a more reliable value of K-e for use in optical-based soot diagnostics. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Illinois, Dept Mech Engn, Chicago, IL 60607 USA. NIST, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Sandia Natl Labs, Unsteady & React Fluid Mech, Albuquerque, NM 87185 USA. RP Choi, MY (reprint author), Univ Illinois, Dept Mech Engn, 842 W Taylor St, Chicago, IL 60607 USA. NR 19 TC 20 Z9 20 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD SEP PY 2000 VL 43 IS 18 BP 3299 EP 3303 DI 10.1016/S0017-9310(99)00382-8 PG 5 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 333YY UT WOS:000088159400004 ER PT J AU Browne, S Dongarra, J Garner, N Ho, G Mucci, P AF Browne, S Dongarra, J Garner, N Ho, G Mucci, P TI A portable programming interface for performance evaluation on modern processors SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article; Proceedings Paper CT 1st NASA Workshop on Performance Engineered Information Systems CY SEP 28, 1998-SEP 29, 1999 CL MOFFETT FIELD, CALIFORNIA SP NASA, NAS Syst Div AB The purpose of the PAPI project is to specify a standard application programming interface (API) for accessing hardware performance counters available on most modern microprocessors. These counters exist as a small set of registers that count events, which are occurrences of specific signals and states related to the processor's function. Monitoring these events facilitates correlation between the structure of source/object code and the efficiency of the mapping of that code to the underlying architecture. This correlation has a variety of uses in performance analysis, including hand tuning, compiler optimization, debugging, benchmarking, monitoring, and performance modeling. In addition, it is hoped that this information will prove useful in the development of new compilation technology as well as in steering architectural development toward alleviating commonly occurring bottlenecks in high performance computing. C1 Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Dongarra, J (reprint author), Univ Tennessee, Dept Comp Sci, 104 Ayres Hall, Knoxville, TN 37996 USA. RI Dongarra, Jack/E-3987-2014 NR 9 TC 228 Z9 234 U1 1 U2 7 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 1094-3420 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD FAL PY 2000 VL 14 IS 3 BP 189 EP 204 DI 10.1177/109434200001400303 PG 16 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 416PU UT WOS:000167790000003 ER PT J AU McDeavitt, SM AF McDeavitt, SM TI Uranium processing for the nuclear fuel cycle SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Editorial Material C1 Argonne Natl Lab, Div Chem Technol, Mat Dev Sect, Argonne, IL 60439 USA. RP McDeavitt, SM (reprint author), Argonne Natl Lab, Div Chem Technol, Mat Dev Sect, Argonne, IL 60439 USA. NR 4 TC 0 Z9 0 U1 2 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD SEP PY 2000 VL 52 IS 9 BP 11 EP 11 DI 10.1007/s11837-000-0180-3 PG 1 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 353QH UT WOS:000089286600001 ER PT J AU Westphal, BR Mariani, RD AF Westphal, BR Mariani, RD TI Uranium processing during the treatment of sodium-bonded spent nuclear fuel SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article AB Several key technical areas have been developed during a demonstration program at Argonne National Laboratory to advance the electrometallurgical treatment of spent nuclear fuel, including equipment operating conditions, uranium-product purity and recovery, and processing rates. Operating conditions for three integral processing steps were optimized based on minimizing the impurities to the final uranium product while meeting program goals for processing rates. The overall recovery of uranium during the process steps was influenced by process conditions as well as the production; rates set forth for the demonstration program. C1 Argonne Natl Lab, Nucl Technol Dept, Idaho Falls, ID 83403 USA. RP Westphal, BR (reprint author), Argonne Natl Lab, Nucl Technol Dept, POB 2528, Idaho Falls, ID 83403 USA. NR 18 TC 14 Z9 14 U1 0 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD SEP PY 2000 VL 52 IS 9 BP 21 EP 25 DI 10.1007/s11837-000-0182-1 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 353QH UT WOS:000089286600003 ER PT J AU Cachau, R Howard, E Barth, P Mitschler, A Chevrier, B Lamour, V Joachimiak, A Sanishvili, R Van Zandt, M Sibley, E Moras, D Podjarny, A AF Cachau, R Howard, E Barth, P Mitschler, A Chevrier, B Lamour, V Joachimiak, A Sanishvili, R Van Zandt, M Sibley, E Moras, D Podjarny, A TI Model of the catalytic mechanism of human aldose reductase based on quantum chemical calculations SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT Conference on X-Rays and Matter (RX 99) CY DEC 07-10, 1999 CL ECOLE NATL SUPER ARTS & IND, STRASBOURG, FRANCE HO ECOLE NATL SUPER ARTS & IND ID CRYSTAL-STRUCTURE; INHIBITORS; BINDING; SITE AB Aldose Reductase is an enzyme involved in diabetic complications, thoroughly studied for the purpose of inhibitor development. The structure of an enzyme-inhibitor complex solved at sub-atomic resolution has been used to develop a model for the catalytic mechanism. This model has been refined using a combination of Molecular Dynamics and Quantum calculations. It shows that the proton donation, the subject of previous controversies, is the combined effect of three residues: Lys 77, Tyr 48 and His 110. Lys 77 polarises the Tyr 48 OH group, which donates the proton to His 110, which becomes doubly protonated. His 110 then moves and donates the proton to the substrate. The key information from the sub-atomic resolution structure is the orientation of the ring and the single protonation of the His 110 in the enzyme-inhibitor complex. This model is in full agreement with all available experimental data. C1 IGBMC, UPR Biol Struct, F-67404 Illkirch, France. NCI, SAIC, Adv Biomed Comp Ctr, Frederick, MD 21701 USA. Univ Louis Pasteur Strasbourg 1, Inst Chim, Lab Chim Organ Biol, F-67008 Strasbourg, France. Argonne Natl Lab, Biosci Div, Argonne, IL USA. Inst Diabet Discovery Inc, Branford, CT USA. RP Cachau, R (reprint author), IGBMC, UPR Biol Struct, 1 Rue Laurent Fries, F-67404 Illkirch, France. NR 22 TC 27 Z9 27 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2000 VL 10 IS P10 BP 3 EP 13 DI 10.1051/jp4:20001001 PG 11 WC Physics, Multidisciplinary SC Physics GA 367HE UT WOS:000090055000001 ER PT J AU Thissell, WR Macdougall, DAS Miller, D Simmonds, KE Everett, RK Matic, P Brooks, R Tonks, D AF Thissell, WR Macdougall, DAS Miller, D Simmonds, KE Everett, RK Matic, P Brooks, R Tonks, D TI Quantitative damage evolution in incipiently failed 10100 Cu SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 6th International Conference on Mechanical and Physical Behaviour of Materials Under Dynamic Loading CY SEP 25-29, 2000 CL KRAKOW, POLAND SP Dymat Assoc, Inst Fundamental Technol Res, Warsaw ID STRESS AB Two different plates of 10100 Cu (> 99.99 % Cu) were incipiently failed using flyer plate impact in a gas gun equipped with soft recovery. The cleanliness of the plates was assessed using the cold crucible melt technique. One of the plates was also tested using a momentum trapped tensile Hopkinson split pressure bar (THSPB). The recovered specimens were metallographically sectioned, polished, and etched. The resulting damage was also quantified using image analysis and optical profilometry. Micro computed tomography was also performed on two flyer plate specimens and these three dimensional measurements are compared to the sectional measurements. The quantified damage is statistically analyzed for porosity, spatially resolved volumetric void number densities and size distributions, near-neighbor distances, and clustering. A comparison is made in the THSPB tests between the relative contributions of the texture development and damage accumulation towards the overall mechanical behavior of the material. C1 Univ Calif Los Alamos Natl Lab, MST 08, Los Alamos, NM 87545 USA. RP Thissell, WR (reprint author), Univ Calif Los Alamos Natl Lab, MST 08, POB 1663, Los Alamos, NM 87545 USA. OI Everett, Richard/0000-0002-6725-9442 NR 8 TC 0 Z9 0 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2000 VL 10 IS P9 BP 299 EP 304 DI 10.1051/jp4:2000950 PG 6 WC Physics, Multidisciplinary SC Physics GA 361EQ UT WOS:000089710300051 ER PT J AU Miller, DA Thissell, WR Macdougall, DAS AF Miller, DA Thissell, WR Macdougall, DAS TI Dynamic tensile plasticity and damage evolution in shape-memory Ni-Ti SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 6th International Conference on Mechanical and Physical Behaviour of Materials Under Dynamic Loading CY SEP 25-29, 2000 CL KRAKOW, POLAND SP Dymat Assoc, Inst Fundamental Technol Res, Warsaw ID MARTENSITIC-TRANSFORMATION; BEHAVIOR; ALLOYS AB Several material systems exhibit temperature and/or stress induced phase transformations over the temperature and loading range which they may likely experience in service. The most notable example is the near stoichiometric system NiTi. In this research, NiTi specimens of various geometries are subjected to a stress induced martensitic transformation in a Tensile Split Hopkinson Pressure Bar. This loading device allows for investigation of the martensitic transformation under strain rates ranging from 500-4000 epsilon-sec(-1). In addition to the large strain rates, the specimens are tested to large strain levels such that void growth and failure mechanisms are identified. The specimens failed in a mixed mode, ductile void growth followed by transgranular failure. The void growth in incipient failure specimens showed ductile void growth throughout the specimen cross-section. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Miller, DA (reprint author), Univ Calif Los Alamos Natl Lab, MS G755,POB 1663,MST 08, Los Alamos, NM 87545 USA. NR 16 TC 8 Z9 8 U1 2 U2 5 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2000 VL 10 IS P9 BP 341 EP 346 DI 10.1051/jp4:2000957 PG 6 WC Physics, Multidisciplinary SC Physics GA 361EQ UT WOS:000089710300058 ER PT J AU Sarrazin, P Blake, D Bish, D Vaniman, D Chipera, S Collins, SA Elliott, ST AF Sarrazin, P Blake, D Bish, D Vaniman, D Chipera, S Collins, SA Elliott, ST TI In situ investigation of ices and hydrous minerals at the lunar poles using a combined X-ray fluorescence and diffraction instrument SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT Conference on X-Rays and Matter (RX 99) CY DEC 07-10, 1999 CL ECOLE NATL SUPER ARTS & IND, STRASBOURG, FRANCE HO ECOLE NATL SUPER ARTS & IND ID WATER AB There is a growing body of evidence that points to the survival of water or hydrous minerals on the Moon and the potential for large aqueous reservoirs in shadowed craters at the lunar poles. CheMin, an XRD/XRF instrument that is currently under development, could provide a definitive test of whether the polar hydrogen signal measured by the recent Lunar Prospector mission is an indication of a significant water reservoir or merely reflects an anomalously rich accumulation of solar-wind hydrogen. Proposed enhancements of CheMin could be used in conjunction with a drilling system capable of penetrating the upper few tens of centimeters of the lunar regolith to search for ices or hydrous minerals. This advanced version of the CheMin instrument would be within the size, mass, and power constraints of Ariane 5 micromissions. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. ENESAD, F-21079 Dijon, France. Univ Calif Los Alamos Natl Lab, EES1, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sarrazin, P (reprint author), NASA, Ames Res Ctr, MS 239-4, Moffett Field, CA 94035 USA. NR 12 TC 5 Z9 5 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2000 VL 10 IS P10 BP 343 EP 352 DI 10.1051/jp4:20001037 PG 10 WC Physics, Multidisciplinary SC Physics GA 367HE UT WOS:000090055000037 ER PT J AU Zurek, AK Hixson, RS Anderson, WW Vorthman, JE Gray, GT Tonks, DL AF Zurek, AK Hixson, RS Anderson, WW Vorthman, JE Gray, GT Tonks, DL TI Elastic response of U-Nb (6%) alloy SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 6th International Conference on Mechanical and Physical Behaviour of Materials Under Dynamic Loading CY SEP 25-29, 2000 CL KRAKOW, POLAND SP Dymat Assoc, Inst Fundamental Technol Res, Warsaw AB Previous work done to measure spall response of U-Nb(6%) alloy showed a somewhat surprising result. In all experiments done previously no evidence for an elastic wave was observed; that is, no two wave structure was detected. In this paper we report on the results of new experiments done to look at the effect in more detail. Dedicated experiments were done to look for evidence of elastic wave under compression, and preliminary results are reported. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Zurek, AK (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 8 TC 9 Z9 9 U1 0 U2 9 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2000 VL 10 IS P9 BP 677 EP 682 DI 10.1051/jp4:20009113 PG 6 WC Physics, Multidisciplinary SC Physics GA 361EQ UT WOS:000089710300114 ER PT J AU Macdougall, DAS Thissell, WR AF Macdougall, DAS Thissell, WR TI Quantitative damage evolution in dynamic incipiently failed Ti-6Al-4V SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 6th International Conference on Mechanical and Physical Behaviour of Materials Under Dynamic Loading CY SEP 25-29, 2000 CL KRAKOW, POLAND SP Dymat Assoc, Inst Fundamental Technol Res, Warsaw ID MECHANISMS AB Incipient and full failure tests were performed using a momentum-trapped tensile Hopkinson split pressure bar at strain rates of similar to 2000 /s. Aerospace grade Ti-6Al-4V is used in this study as a two-phase model material. The sample geometries used included cylindrical uniaxial stress tension specimens and the Hancock and Mackenzie E-notch geometry [1] to explore stress states from 1/6 less than or equal to -P/2 tau less than or equal to 1/3. The momentum trapping [2] resulted in single stress pulse loading. The recovered samples were sectioned, and metallographically analyzed. The resulting damage was quantified using image analysis. Voids were found in all of the arrested tensile specimens of less than or equal to 20 mu m in diameter. The maximum porosity was found to increase with plastic strain to approximately 1.1% at 85% of the energy required to fail the specimen. C1 Univ Calif Los Alamos Natl Lab, Struct Property Relationships MST08, Los Alamos, NM 87545 USA. RP Macdougall, DAS (reprint author), Univ Calif Los Alamos Natl Lab, Struct Property Relationships MST08, MS-G755, Los Alamos, NM 87545 USA. NR 3 TC 0 Z9 0 U1 2 U2 3 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2000 VL 10 IS P9 BP 729 EP 734 DI 10.1051/jp4:20009121 PG 6 WC Physics, Multidisciplinary SC Physics GA 361EQ UT WOS:000089710300122 ER PT J AU Gray, GT Hayes, DB Hixson, RS AF Gray, GT Hayes, DB Hixson, RS TI Influence of the shock-induced alpha-epsilon transition in Fe on its post-shock substructure evolution and mechanical behavior SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 6th International Conference on Mechanical and Physical Behaviour of Materials Under Dynamic Loading CY SEP 25-29, 2000 CL KRAKOW, POLAND SP Dymat Assoc, Inst Fundamental Technol Res, Warsaw ID PHASE-TRANSITION; STRAIN RATES; IRON; WAVE AB The effect of shock-prestraining high-purity Fe, above and below the 13 GPa phase transition, on postshock compressive stress-strain behavior and substructure evolution is presented. The degree of shock hardening in Fe is higher for shock strength above the transition than below it. The substructure also displayed more deformation twinning for shocks above the phase transition than below. The shock hardening in Fe varied with propagation distance. Modeling shock propagation in Fe revealed that for the geometry used, the transition wave was overtaken and quenched by the rarefaction release explaining the gradient in shock hardening. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gray, GT (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 22 TC 11 Z9 15 U1 1 U2 3 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2000 VL 10 IS P9 BP 755 EP 760 PG 6 WC Physics, Multidisciplinary SC Physics GA 361EQ UT WOS:000089710300126 ER PT J AU Thissell, WR Zurek, AK Macdougall, DAS Tonks, D AF Thissell, WR Zurek, AK Macdougall, DAS Tonks, D TI Damage evolution and damage model validation in spalled tantalum SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 6th International Conference on Mechanical and Physical Behaviour of Materials Under Dynamic Loading CY SEP 25-29, 2000 CL KRAKOW, POLAND SP Dymat Assoc, Inst Fundamental Technol Res, Warsaw ID SPALLATION; FRACTURE; FAILURE; SOLIDS AB The dynamic damage resistance of two grades of very clean tantalum is compared. The materials were loaded to incipient failure using an 80 mm gas gun equipped with soft recovery using a parallel flyer plate experimental configuration. Both loading time and applied shock pressure was varied from 1.1-2 mu s and 5.6-9.8 GPa, respectively. A VISAR recorded the back surface velocity. The recovered samples were metallographically sectioned, polished, and etched. Image analysis and optical profilometry quantified the resulting damage. Longitudinal porosity distributions of the tests are compared. A calibrated hydrocode based damage model was used to simulate the tests. We compare predicted and experimental measurements of free surface velocity and porosity. The model also produced free surface pullback signals suggesting high spall strength with little evolved porosity. This is further confirmation that in clean, high Peierls energy materials the VISAR pullback signal is associated with the creation of a region of enormous hydrostatic tensile stresses in the material, but is relatively distinct from the void coalescence process. A transition in coalescence mechanism, from primarily void growth impingement to long-range plastic instabilities, occurs with increasing hydrostatic tension and increasing stress pulse duration. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Thissell, WR (reprint author), Univ Calif Los Alamos Natl Lab, MST-08, Los Alamos, NM 87545 USA. NR 19 TC 9 Z9 9 U1 1 U2 5 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2000 VL 10 IS P9 BP 769 EP 774 DI 10.1051/jp4:20009127 PG 6 WC Physics, Multidisciplinary SC Physics GA 361EQ UT WOS:000089710300128 ER PT J AU Millett, JCF Gray, GT Bourne, NK AF Millett, JCF Gray, GT Bourne, NK TI Lateral stress measurements and shear strength in a shock-loaded gamma-TiAl alloy SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 6th International Conference on Mechanical and Physical Behaviour of Materials Under Dynamic Loading CY SEP 25-29, 2000 CL KRAKOW, POLAND SP Dymat Assoc, Inst Fundamental Technol Res, Warsaw ID MECHANICAL-PROPERTIES; TITANIUM ALUMINIDES; DYNAMIC COMPACTION; STRAIN-RATE; BEHAVIOR; WAVES AB Manganin stress gauges have been placed in samples of a gamma-titanium aluminide ahoy in such orientation that renders them sensitive to the lateral component of stress during one-dimensional shock loading. The impact stresses were in the range 1.8 to 6 GPa. The resultant stress histories show clear evidence of a transition from elastic to plastic behaviour, which, through the elastic relations correlates with the Hugoniot Elastic Limit of this material. In combination with the longitudinal stress data, it has been possible to use the lateral stresses from this series of experiments to calculate the shear strength during shock loading. The Hugoniot of the gamma-titanium aluminide studied is seen to be significantly different than a standard alpha-beta Ti-alloy such as Ti-6Al-4V. The results show this titanium aluminide ahoy displays a significant degree of hardening with increasing shock stress. C1 Cranfield Univ, Royal Mil Coll Sci, Swindon SN6 8LA, Wilts, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Millett, JCF (reprint author), Cranfield Univ, Royal Mil Coll Sci, Swindon SN6 8LA, Wilts, England. RI Bourne, Neil/A-7544-2008 NR 22 TC 5 Z9 5 U1 0 U2 2 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2000 VL 10 IS P9 BP 781 EP 785 DI 10.1051/jp4:20009129 PG 5 WC Physics, Multidisciplinary SC Physics GA 361EQ UT WOS:000089710300130 ER PT J AU Tonks, DL Alexander, DJ Sheffield, SA Robbins, DL Zurek, AK Thissell, WR AF Tonks, DL Alexander, DJ Sheffield, SA Robbins, DL Zurek, AK Thissell, WR TI Spallation strength of single crystal and polycrystalline copper SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 6th International Conference on Mechanical and Physical Behaviour of Materials Under Dynamic Loading CY SEP 25-29, 2000 CL KRAKOW, POLAND SP Dymat Assoc, Inst Fundamental Technol Res, Warsaw AB The spallation strength of single crystal copper foils 100 micrometers thick of the < 110 > and < 100 > orientations and of polycrystalline copper foils has been determined. Laser driving was used to launch miniature plates. Also, the spallation strength of polycrystalline copper was measured using conventional gas gun techniques and plates for comparison. Experimental measurements include VISAR records of the free surface particle velocity and micrographs of recovered flyers. A ID hydrocode was used to simulate the VISAR records to determine the dynamic pressure history of the spallation process. Judging by the calculated pressures, it was found that the < 110 > foils were somewhat stronger than the < 100 > foils, which were about twice as strong as the polycrystalline foils. These were, in turn, substantially stronger than the larger sample plates (1.5 mm thick) of the gas gun. In the polycrystalline foils, small voids are found in recovered samples impacted at flyer plate velocities almost producing spallation in the gas gun, indicating that this sparse damage in the foils is able to grow substantially more in the much larger gas gun plates and under much slower gas gun loading. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Tonks, DL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 3 TC 8 Z9 8 U1 0 U2 4 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2000 VL 10 IS P9 BP 787 EP 792 DI 10.1051/jp4:20009130 PG 6 WC Physics, Multidisciplinary SC Physics GA 361EQ UT WOS:000089710300131 ER PT J AU Evenson, DP Jost, LK Corzett, M Balhorn, R AF Evenson, DP Jost, LK Corzett, M Balhorn, R TI Characteristics of human sperm chromatin structure following an episode of influenza and high fever: A case study SO JOURNAL OF ANDROLOGY LA English DT Article DE infertility; SCSA; DNA denaturation ID NORMAL FEMALE MICE; DNA STRAND BREAKS; FLOW-CYTOMETRY; STRUCTURE ASSAY; MAMMALIAN SPERM; EMBRYO QUALITY; SEMEN QUALITY; DENATURATION; FERTILITY; EXPOSURE AB Semen samples from a fertile patient presenting with influenza and a 1-day fever of 39.9 degrees C were obtained and analyzed at 13-66 days postfever (dpf) for sperm nuclear proteins, DNA stainability, free thiols (-SH), and susceptibility to DNA denaturation in situ. At 18 dpf, 36% of sperm demonstrated denatured DNA as measured by the sperm chromatin structure assay (SCSA), and decreased to 23% by 39 dpf. Samples at 33 and 39 dpf contained 49% and 30%, respectively, of cells with increased DNA stainability (HIGRN). A unique sperm nuclear protein band migrating between histones and protamines on acid-urea gels appeared at 33 and 39 dpf and nearly disappeared by 52 dpf. Amino acid sequencing of the first 8 N-terminal residues identified this protein as the precursor to protamine 2. The protamine P1 and P2 ratio remained normal, whereas the histone to protamine ratio increased slightly at 33 to 39 dpf. Flow cytometric measurements of nuclear -SH groups revealed the greatest reduction in free nuclear thiols at 33 dpf, and returned to normal by 45 dpf. The time of appearance of the unprocessed protamine 2 precursor and the relative increase in histone suggest a fever-related disruption of the synthesis of mRNA that codes for a P2 processing enzyme or enzymes. increased DNA staining is likely due to the increased histone/protamine ratio. This case study demonstrates that fever/influenza can have latent effects on sperm chromatin structure and may result in transient release of abnormal sperm. C1 S Dakota State Univ, Dept Chem & Biochem, Brookings, SD 57007 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA USA. RP Evenson, DP (reprint author), S Dakota State Univ, Dept Chem & Biochem, Box 2170,Anim Sci Complex 136, Brookings, SD 57007 USA. NR 45 TC 94 Z9 99 U1 2 U2 5 PU AMER SOC ANDROLOGY, INC PI LAWRENCE PA C/O ALLEN PRESS, INC PO BOX 368, LAWRENCE, KS 66044 USA SN 0196-3635 J9 J ANDROL JI J. Androl. PD SEP-OCT PY 2000 VL 21 IS 5 BP 739 EP 746 PG 8 WC Andrology SC Endocrinology & Metabolism GA 349BG UT WOS:000089023500018 PM 10975421 ER PT J AU Smyth, AW Masri, SF Caughey, TK Hunter, NF AF Smyth, AW Masri, SF Caughey, TK Hunter, NF TI Surveillance of mechanical systems on the basis of vibration signature analysis SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article ID IDENTIFICATION AB A comprehensive experimental study is presented to assess the utility of a proposed structural health monitoring and damage detection methodology based on vibration signature analysis of the rest article. The approach uses a time-domain least-squares-based method to identify the reduced-order system matrices of an equivalent linear model whose order matches the number of available sensors. A quantification of the level of the system nonlinearity is obtained by determining the residual nonlinear forces involved In the system dynamics. The approach is applied to an intricate mechanical system about which virtually no information was available: i.e., the system was essentially a ''black box.'' By using similar measurements from a reference version of the test article and two subsequently modified versions, it is shown that through the use of higher-order statistics involving the probability density functions of key system parameters, a reliable measure of the extent of variation of the system influence functions may be obtained The use of measures of the identified quantities' dispersion offers a practical method for quantifying the reliability of the estimated changes involved in dealing with real-world (i.e., not noise-free) measurements that result in uncertain estimates of the physical changes in the article bring monitored. C1 Columbia Univ, Sch Engn & Appl Sci, New York, NY 10027 USA. Univ So Calif, Sch Engn, Los Angeles, CA 90089 USA. CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Smyth, AW (reprint author), Columbia Univ, Sch Engn & Appl Sci, New York, NY 10027 USA. OI Smyth, Andrew/0000-0001-9037-306X NR 29 TC 27 Z9 27 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD SEP PY 2000 VL 67 IS 3 BP 540 EP 551 DI 10.1115/1.1313535 PG 12 WC Mechanics SC Mechanics GA 404PL UT WOS:000167109500013 ER PT J AU Rodrigues, W Sakata, O Lee, TL Walko, DA Marasco, DL Bedzyk, MJ AF Rodrigues, W Sakata, O Lee, TL Walko, DA Marasco, DL Bedzyk, MJ TI X-ray scattering studies of surfactant mediated epitaxial growth of Si/Ge/Si(001) heterostructures SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID STRAIN RELAXATION; GE FILMS; SI(001); DIFFRACTION; GE/SI(001) AB The strain and morphology of Si/Ge films grown by surfactant mediated molecular beam epitaxy on Si(001) with Bi as the surfactant were studied with grazing-incidence x-ray diffraction, x-ray reflectivity, low-energy electron diffraction, and Auger electron spectroscopy. Bi is observed to prevent the intermixing of Ge and Si layers by inhibiting Ge segregation in Si. Without a surfactant the critical thickness of Ge/Si(001) is 3 monolayers (ML). Using Bi, two-dimensional growth of Ge is observed for films up to 10 ML in thickness, with the onset of strain relaxation occurring at 7 ML of Ge growth. At 10 ML, the top Ge atomic layers are only partially relaxed. This is achieved by introducing roughness at the interface of the Ge and Si layers. (C) 2000 American Institute of Physics. [S0021-8979(00)07418-1]. C1 Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. Argonne Natl Lab, XFD, Argonne, IL 60439 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Rodrigues, W (reprint author), Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. RI Bedzyk, Michael/B-7503-2009; SAKATA, Osami/H-2621-2011; Bedzyk, Michael/K-6903-2013 NR 18 TC 12 Z9 12 U1 0 U2 4 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 2000 VL 88 IS 5 BP 2391 EP 2394 DI 10.1063/1.1288703 PG 4 WC Physics, Applied SC Physics GA 345BX UT WOS:000088796500035 ER PT J AU Monteiro, OR Ager, JW Lee, DH Yu Lo, R Walter, KC Nastasi, M AF Monteiro, OR Ager, JW Lee, DH Yu Lo, R Walter, KC Nastasi, M TI Annealing of nonhydrogenated amorphous carbon films prepared by filtered cathodic arc deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DIAMOND-LIKE-CARBON; PULSED-LASER DEPOSITION; VACUUM-ARC; THERMAL-STABILITY; RESIDUAL-STRESS; ELASTIC-MODULUS; A-C; HARDNESS; SUBPLANTATION; RELAXATION AB The effect of postdeposition annealing to 600 degrees C in vacuum on the hardness, modulus, film stress, and sp(3) content of nonhydrogenated amorphous carbon was studied. The films were deposited using a filtered cathodic arc source and the film properties were varied by controlling the substrate bias. In films with an initial sp(3) content of greater than 80% a significant decrease (from 10.5 GPa to less than 2 GPa) in the level of compressive stress was observed without deterioration of the mechanical properties. In films with an initial sp(3) content of 50%, the stress and hardness remained constant. Films with lower sp(3) content showed a significant increase in the level of stresses and only a marginal decrease in hardness. The evolution of stresses and hardness with annealing is discussed in light of a proposed microstructure of these amorphous films. (C) 2000 American Institute of Physics. [S0021-8979(00)03618-5]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Comp Mech Lab, Berkeley, CA 94720 USA. RP Monteiro, OR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. OI Ager, Joel/0000-0001-9334-9751 NR 31 TC 34 Z9 34 U1 0 U2 1 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 2000 VL 88 IS 5 BP 2395 EP 2399 DI 10.1063/1.1288221 PG 5 WC Physics, Applied SC Physics GA 345BX UT WOS:000088796500036 ER PT J AU Grecu, D Compaan, AD Young, D Jayamaha, U Rose, DH AF Grecu, D Compaan, AD Young, D Jayamaha, U Rose, DH TI Photoluminescence of Cu-doped CdTe and related stability issues in CdS/CdTe solar cells SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CADMIUM TELLURIDE; COMPLEX-FORMATION; SEMICONDUCTORS; IMPURITIES; DIFFUSION; FILM AB We explore Cu electronic states in CdTe using photoluminescence as the main investigative method. Our results are consistent with some Cu atoms occupying substitutional positions on the Cd sublattice and with others forming Frenkel pairs of the type Cu-i(+)-V-Cd(-) involving an interstitial Cu and a Cd vacancy. In addition, we find that Cu-doped CdTe samples exhibit a significant "aging" behavior, attributable to the instability of Cu acceptor states as verified by our Hall measurements. The aging appears to be reversible by a 150-200 degrees C anneal. Our results are used to explain efficiency degradation of some CdTe solar-cell devices which use Cu for the formation of a backcontact. (C) 2000 American Institute of Physics. [S0021-8979(00)05217-8]. C1 Univ Toledo, Toledo, OH 43606 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. First Solar LLC, Perrysburg, OH 43551 USA. RP Grecu, D (reprint author), Univ Toledo, 2801 W Bancroft St, Toledo, OH 43606 USA. NR 50 TC 60 Z9 60 U1 5 U2 27 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 2000 VL 88 IS 5 BP 2490 EP 2496 AR PII [S0021-8979(00)05217-8] DI 10.1063/1.1287414 PG 7 WC Physics, Applied SC Physics GA 345BX UT WOS:000088796500050 ER PT J AU Suenaga, M Chiba, T Ashworth, SP Welch, DO Holesinger, TG AF Suenaga, M Chiba, T Ashworth, SP Welch, DO Holesinger, TG TI Alternating current losses in stacked Bi2Sr2Ca2Cu3O10/Ag tapes in perpendicular magnetic fields SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SHEATHED (BI,PB)(2)SR2CA2CU3O10 TAPES; AC LOSSES; CRITICAL-STATE AB Alternating current losses in stacks of powder-in-tube-processed Bi2Sr2Ca2Cu3O10/Ag tapes were measured in perpendicular magnetic fields and compared with calculated hysteresis losses based on the critical-state model. Four main factors had to be taken into account for the calculations of the losses: (1) the inclusion of the area of the Ag sheath in determining the critical-current densities of the stacks, (2) the zero-applied-field critical currents I-c(perpendicular to)(0) with truly perpendicular fields only, not the standard self-field critical current I-c(S)(0), and (3) the field-dependent critical current I-c(H), e.g., the Kim's model, and (4) the subtraction of the frequency-dependent losses at very high fields. With these considerations, the agreement between the calculated and the measured values of the losses is excellent for fields beyond the full-penetration fields. However, these factors did not totally account for the low-field losses. (C) 2000 American Institute of Physics. [S0021-8979(00)04617-X]. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Suenaga, M (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. NR 22 TC 11 Z9 11 U1 0 U2 0 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 2000 VL 88 IS 5 BP 2709 EP 2717 AR PII [S0021-8979(00)04617-X] DI 10.1063/1.1287408 PG 9 WC Physics, Applied SC Physics GA 345BX UT WOS:000088796500086 ER PT J AU Ashworth, SP Maley, M Suenaga, M Foltyn, SR Willis, JO AF Ashworth, SP Maley, M Suenaga, M Foltyn, SR Willis, JO TI Alternating current losses in YBa2Cu3O7-x coated conductors on technical substrates SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID AC MAGNETIC-FIELDS; TRANSPORT CURRENTS; TAPES AB We report on measurements of the ac losses of YBa2Cu3O7-x conductors on technical substrates. The samples are taken from conductors 1 m long produced with an ion beam assisted deposition step in the manufacturing process yielding 1 cm wide conductors with critical currents approaching 100 A at 77.4 K. The losses due to combinations of ac transport currents and ac magnetic fields were measured calorimetrically and the results compared to theoretical estimates. While the results of our measurements are similar to the theoretical estimates, there are some important differences in the qualitative behavior. (C) 2000 American Institute of Physics. [S0021-8979(00)05418-9]. C1 Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, CA 93440 USA. RP Ashworth, SP (reprint author), Brookhaven Natl Lab, Div Mat Sci, POB 5000, Upton, NY 11973 USA. NR 9 TC 30 Z9 31 U1 0 U2 4 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 2000 VL 88 IS 5 BP 2718 EP 2723 DI 10.1063/1.1288505 PG 6 WC Physics, Applied SC Physics GA 345BX UT WOS:000088796500087 ER PT J AU Hsueh, CH AF Hsueh, CH TI Analyses of edge effects on residual stresses in film strip/substrate systems SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FINITE-ELEMENT CALCULATION; FIBER PULL-OUT; THERMAL-STRESSES; GAAS FILMS; RELAXATION; STRAIN; RAMAN; SUBSTRATE; EPILAYERS; LINES AB The residual stress distribution in a thin-film strip overlaid on a substrate is influenced by the edges of the strip. An analytical model is developed to derive a closed-form solution for the stress distribution along the film width. Because the film is much thinner than the substrate, the stress variation through the film thickness is ignored; however, the stress variation through the substrate thickness is considered in the analysis. Compared to the existing analytical models, the present model is more rigorous and the analytical results agree better with both finite element results and experimental measurements. (C) 2000 American Institute of Physics. [S0021-8979(00)02218-0]. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Hsueh, CH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Hsueh, Chun-Hway/G-1345-2011 NR 29 TC 22 Z9 22 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2000 VL 88 IS 5 BP 3022 EP 3028 DI 10.1063/1.1288161 PG 7 WC Physics, Applied SC Physics GA 345BX UT WOS:000088796500133 ER PT J AU Lee, SH Cheong, HM Liu, P Smith, D Tracy, CE Mascanrenhas, A Pitts, JR Deb, SK AF Lee, SH Cheong, HM Liu, P Smith, D Tracy, CE Mascanrenhas, A Pitts, JR Deb, SK TI Gasochromic mechanism in a-WO3 thin films based on Raman spectroscopic studies SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID COLOR-CENTERS AB The gasochromic mechanism in amorphous tungsten oxide films has been investigated using Raman scattering measurements. The Raman spectra of as-deposited films show two strong peaks at 770 and 950 cm(-1) due to vibrations of the O-W6+-O and W6+=O bonds, respectively. When the Pd/a-WO3 films are gasochromically colored by exposure to diluted hydrogen gas, extra Raman peaks due to O-W5+-O and W5+=O bonds appear at 330 and 450 cm(-1), respectively. The Raman spectra of a-WO3 films bleached with isotopic heavy oxygen (O-18) show that the gasochromic coloration in a-WO3 films is directly related to the double injection of hydrogen ions and electrons. (C) 2000 American Institute of Physics. [S0021-8979(00)04517-5]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Sogang Univ, Dept Phys, Seoul 121742, South Korea. DCH Technol Inc, Valencia, CA 91355 USA. RP Lee, SH (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Lee, Sehee/A-5989-2011; Cheong, Hyeonsik/D-7424-2012; Liu, Ping/I-5615-2012 OI Cheong, Hyeonsik/0000-0002-2347-4044; NR 13 TC 66 Z9 67 U1 2 U2 16 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 2000 VL 88 IS 5 BP 3076 EP 3078 DI 10.1063/1.1287407 PG 3 WC Physics, Applied SC Physics GA 345BX UT WOS:000088796500143 ER PT J AU Osterwald, CR Emery, KA AF Osterwald, CR Emery, KA TI Spectroradiometric sun photometry SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SOLAR-RADIATION; UNCERTAINTY AB This paper presents a method for calculating atmospheric transmittance from direct-beam solar spectral irradiance measurements under cloudless skies by treating spectral irradiance as a multichannel sun photometer. Computing the ratio of the measured spectral irradiance to the extraterrestrial spectral irradiance at the top of the atmosphere produces the atmospheric transmittance as a function of wavelength. Individual band absorber amounts and scattering parameters, based on the LOWTRAN 7 atmospheric transmittance model, are then extracted from the transmittance using iterative fitting over wavelength regions where only a few species are active. Using these parameters to extrapolate the entire terrestrial solar spectrum, the wavelength-integrated spectral irradiance is shown to be within 2% of the total irradiance measured with an absolute cavity radiometer. Instrumentation and procedures that have been used with the method at the National Renewable Energy Laboratory since 1987 are described, along with a specific application of the method. C1 NREL, Golden, CO 80401 USA. RP Emery, KA (reprint author), NREL, 1617 Cole Blvd, Golden, CO 80401 USA. NR 32 TC 12 Z9 13 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD SEP PY 2000 VL 17 IS 9 BP 1171 EP 1188 DI 10.1175/1520-0426(2000)017<1171:SSP>2.0.CO;2 PG 18 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 362MY UT WOS:000089782800002 ER PT J AU Bae, KA Longobardi, L Karasawa, K Malone, B Inoue, T Aoki, J Arai, H Inoue, K Lee, TC AF Bae, KA Longobardi, L Karasawa, K Malone, B Inoue, T Aoki, J Arai, H Inoue, K Lee, TC TI Platelet-activating factor (PAF)-dependent transacetylase and its relationship with PAF acetylhydrolases SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID COA-INDEPENDENT TRANSACETYLASE; BETA-SUBUNIT; HL-60 CELLS; PURIFICATION; BRAIN; ACYLTRANSFERASE; BIOSYNTHESIS; EXPRESSION; CLONING; ANALOGS AB Platelet-activating factor (PAF)-dependent transacetylase (TA) is an enzyme that transfers an acetyl group from PAF to acceptor lipids such as lysophospholipids and sphingosine, This enzyme is distributed in membrane and cytosol of the cells. We previously revealed that TA purified from rat kidney membrane showed an amino acid sequence similarity to that of bovine PAF-acetylhydrolase (AH) (II), In the present study, we purified TA from the rat kidney cytosol and analyzed its amino acid sequence, The amino acid sequence of the cytosolic TA is similar to that of bovine PAF-AH (II) and membrane TA, To clarify the relationship between TA and PAF-AH (II), we isolated cDNA of rat PAF-AH (II), The predicted amino acid sequence of rat PAF-AH (II) from isolated cDNA included all the sequences found in TAs purified from the membrane and cytosolic TAs, In addition, monoclonal antibody to recombinant PAF-AH (II) cross-reacted with both cytosolic and membrane TAs, Consistent with sequence identity, recombinant PAF-AH (II) showed TA activity, whereas recombinant PAF-AH Ib, which is a different subtype of intracellular PAF-AHs, did not possess TA activity. Analysis of a series of site-directed mutant PAF-AH (II) proteins showed that TA activity was decreased, whereas PAF-AH activity was not affected in C120S and G2A mutant proteins. Thus, Cys(120) and Gly(2) are implicated in the catalysis of TA reaction in this enzyme. Furthermore, the transfer of acetate from PAF to endogenous acceptor lipids was significantly increased in a time-dependent manner in CHO-KI cells transfected with PAF-AH (II) gene. These results demonstrate that PAF-AH (II) can function, as a TA in intact cells, and PAF-AH (II) and TA are the same enzyme. C1 Oak Ridge Associated Univ, Basic & Appl Res Unit, Oak Ridge, TN 37831 USA. Univ Tokyo, Fac Pharmaceut Sci, Dept Hlth Chem, Bunkyo Ku, Tokyo 113, Japan. RP Lee, TC (reprint author), Oak Ridge Associated Univ, Basic & Appl Res Unit, Oak Ridge, TN 37831 USA. EM leetc@orau.gov OI Aoki, Junken/0000-0001-9435-1896 FU NHLBI NIH HHS [HL-52492] NR 24 TC 24 Z9 25 U1 1 U2 4 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 1 PY 2000 VL 275 IS 35 BP 26704 EP 26709 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 351EL UT WOS:000089144800007 PM 10867005 ER PT J AU Bochkareva, E Korolev, S Bochkarev, A AF Bochkareva, E Korolev, S Bochkarev, A TI The role for zinc in replication protein A SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID SINGLE-STRANDED-DNA; BINDING DOMAIN; 70-KDA SUBUNIT; CRYSTAL-STRUCTURE; A INTERACTIONS; METAL-IONS; FINGER; COMPLEXES; REVEALS; 3'-END AB Heterotrimeric human single stranded DNA (ssDNA)binding protein, replication protein A (RPA), is a central player in DNA replication, recombination, and repair. The C terminus of the largest subunit, RPA70, contains a putative zinc-binding motif and is implicated in complex formation with two smaller subunits, RPA14 and RPA32, The C-terminal domain of RPA70 (RPA70-CTD) was characterized using proteolysis and x-ray fluorescence emission spectroscopy. The proteolytic core of this domain comprised amino acids 432-616, X-ray fluorescence spectra revealed that RPA70-CTD possesses a coordinated Zn(II). The trimeric complex of RPA70-CTD, the ssDNA-binding domain of RPA32 (amino acids 43-171), and RPA14 had strong DNA binding activity. When properly coordinated with zinc, the trimer's affinity to ssDNA was only 3-10-fold less than that of the ssDNA-binding domain in the middle of RPA70. However, the DNA-binding activity of the trimer was dramatically reduced in the presence of chelating agents. Our data indicate that (i) Zn(II) is essential to stabilize the tertiary structure of RPA70-CTD; (ii) RPA70-CTD possesses DNA-binding activity, which is modulated by Zn(II); and (iii) ssDNA binding by the trimer is a synergistic effect generated by the RPA70-CTD and RPA32. C1 Univ Oklahoma, Hlth Sci Ctr, Dept Biochem & Mol Biol, Oklahoma City, OK 73190 USA. Argonne Natl Lab, Struct Biol Ctr, Argonne, IL 60439 USA. RP Bochkarev, A (reprint author), Univ Oklahoma, Hlth Sci Ctr, Dept Biochem & Mol Biol, 975 NE 10th St,BRC-466, Oklahoma City, OK 73190 USA. FU NIGMS NIH HHS [GM61192-01] NR 33 TC 50 Z9 50 U1 0 U2 4 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 1 PY 2000 VL 275 IS 35 BP 27332 EP 27338 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 351EL UT WOS:000089144800089 PM 10856290 ER PT J AU Bhattacharyya, MH Regunathan, A Glesne, DA AF Bhattacharyya, MH Regunathan, A Glesne, DA TI Cadmium-induced bone loss: Early changes in bone cell gene expression. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Biosci, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2000 VL 15 SU 1 MA SU174 BP S374 EP S374 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 346YJ UT WOS:000088898400947 ER PT J AU Herold, DA Burton, DW Fitzgerald, RL Zheng, K Rivera, JD Vogel, JS Buchholz, BA Deftos, LJ AF Herold, DA Burton, DW Fitzgerald, RL Zheng, K Rivera, JD Vogel, JS Buchholz, BA Deftos, LJ TI PTHrP measurement by immunoassay/mass spectrometry. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 Vet Affairs Med Ctr, San Diego, CA 92161 USA. Univ Calif San Diego, San Diego, CA 92103 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RI Buchholz, Bruce/G-1356-2011 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2000 VL 15 SU 1 MA SU088 BP S352 EP S352 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 346YJ UT WOS:000088898400861 ER PT J AU Annunziata, O Rard, JA Albright, JG Paduano, L Miller, DG AF Annunziata, O Rard, JA Albright, JG Paduano, L Miller, DG TI Mutual diffusion coefficients and densities at 298.15 K of aqueous mixtures of NaCl and Na2SO4 for six different solute fractions at a total molarity of 1.500 mol center dot dm(-3) and of aqueous Na2SO4 SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID RAYLEIGH INTERFEROMETRY; CONCENTRATION RATIO; TERNARY DIFFUSION; THERMODYNAMIC PROPERTIES; ISOPIESTIC DETERMINATION; OSMOTIC COEFFICIENTS; MGCL2 CONCENTRATIONS; WIDE-RANGE; 25-DEGREES-C; NACL-MGCL2-H2O AB Isothermal mutual diffusion coefficients (interdiffusion coefficients) were measured for ternary aqueous mixtures of NaCl and Na2SO4 at a constant total molarity of 1.500 mol.dm(-3) at 298.15 K, using Rayleigh interferometry with computerized data acquisition. The experiments were performed at NaCl molarity fractions of z(1) = 1, 0.90, 0.75, 0.50, 0.25, and 0. These measurements supplement our earlier results at total molarities of 0.500 and 1.000 mol.dm(-3). Diffusion coefficients were also measured at three additional concentrations of Na2SO4(aq). Densities of all solutions were measured with a vibrating tube densimeter. At all ternary solution compositions, one cross-term diffusion coefficient has small negative values whereas the other has larger positive values. Comparing the results at 0.500, 1.000, and 1.500 mol.dm(-3) shows that both main-term diffusion coefficients decrease with increasing total concentration at any fixed value of z(1), whereas both cross-term coefficients are shifted in a positive direction. At 1.500 mol.dm(-3) both the NaCl main-term and cross-term diffusion coefficients have a maximum as a function bf z(1), whereas the Na2SO4 cross-term coefficient has a minimum. Trace diffusion coefficients D*(Cl-) = (1.14(5) +/- 0.02) x 10(-9) m(2).s(-1) and D*(SO42-) = (0.80(5) +/- 0.01(5)) x 10(-9) m(2).s(-1) were extrapolated from these results for the Cl-(aq) ion in 1.500 mol.dm(-3) Na2SO4(aq) and for the SO42-(aq) ion in 1.500 mol.dm(-3) NaCl(aq). Values of D*(Cl-) in Na2SO4(aq) and in NaCl(aq) were found to be essentially identical, as were D*(SO42-) in these same two electrolytes, provided the comparisons are made at the same volumetric ionic strengths. C1 Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Earth & Evnironm Sci Di, Livermore, CA 94550 USA. Texas Christian Univ, Dept Chem, Ft Worth, TX 76129 USA. Univ Naples, Dipartimento Chim, I-80134 Naples, Italy. RP Rard, JA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Earth & Evnironm Sci Di, Livermore, CA 94550 USA. OI PADUANO, Luigi/0000-0002-1105-4237 NR 55 TC 7 Z9 7 U1 1 U2 6 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 2000 VL 45 IS 5 BP 936 EP 945 DI 10.1021/je000134s PG 10 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 356FH UT WOS:000089433000045 ER PT J AU Randic, M Vracko, M Nandy, A Basak, SC AF Randic, M Vracko, M Nandy, A Basak, SC TI On 3-D graphical representation of DNA primary sequences and their numerical characterization SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article ID DETOUR MATRIX; SIMILARITY AB In this article we (1) outline the construction of a 3-D "graphical" representation of DNA primary sequences, illustrated on a portion of the human beta globin gene; (2) describe a particular scheme that transforms the above 3-D spatial representation of DNA into a numerical matrix representation; (3) illustrate construction of matrix invariants for DNA sequences; and (4) suggest a data reduction based on statistical analysis of matrix invariants generated for DNA. Each of the four contributions represents a novel development that I we hope will facilitate comparative studies of DNA and open new directions for representation and characterization of DNA primary sequences. C1 Natl Inst Chem, Ljubljana 1001, Slovenia. Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Univ Minnesota, Nat Resources Res Inst, Duluth, MN 55811 USA. Indian Inst Chem Biol, Comp Div, Calcutta 700032, W Bengal, India. RP Basak, SC (reprint author), Natl Inst Chem, POB 3430, Ljubljana 1001, Slovenia. NR 39 TC 249 Z9 257 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0095-2338 J9 J CHEM INF COMP SCI JI J. Chem. Inf. Comput. Sci. PD SEP-OCT PY 2000 VL 40 IS 5 BP 1235 EP 1244 DI 10.1021/ci000034q PG 10 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA 358NG UT WOS:000089563700020 PM 11045819 ER PT J AU Gwaltney, SR Sherrill, CD Head-Gordon, M Krylov, AI AF Gwaltney, SR Sherrill, CD Head-Gordon, M Krylov, AI TI Second-order perturbation corrections to singles and doubles coupled-cluster methods: General theory and application to the valence optimized doubles model SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION; MOLECULAR CALCULATIONS; NONDYNAMIC CORRELATION; WAVE-FUNCTIONS; BASIS SETS; ENERGIES; 5TH-ORDER; EQUATION; RADICALS; ORBITALS AB We present a general perturbative method for correcting a singles and doubles coupled-cluster energy. The coupled-cluster wave function is used to define a similarity-transformed Hamiltonian, which is partitioned into a zeroth-order part that the reference problem solves exactly plus a first-order perturbation. Standard perturbation theory through second-order provides the leading correction. Applied to the valence optimized doubles (VOD) approximation to the full-valence complete active space self-consistent field method, the second-order correction, which we call (2), captures dynamical correlation effects through external single, double, and semi-internal triple and quadruple substitutions. A factorization approximation reduces the cost of the quadruple substitutions to only sixth order in the size of the molecule. A series of numerical tests are presented showing that VOD(2) is stable and well-behaved provided that the VOD reference is also stable. The second-order correction is also general to standard unwindowed coupled-cluster energies such as the coupled-cluster singles and doubles (CCSD) method itself, and the equations presented here fully define the corresponding CCSD(2) energy. (C) 2000 American Institute of Physics. [S0021-9606(00)30130-1]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ So Calif, Dept Chem, Los Angeles, CA 90089 USA. RP Gwaltney, SR (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. OI Gwaltney, Steven/0000-0003-3833-5087; Sherrill, David/0000-0002-5570-7666 NR 40 TC 138 Z9 138 U1 0 U2 3 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 1 PY 2000 VL 113 IS 9 BP 3548 EP 3560 AR PII [S0021-9606(00)30130-1] DI 10.1063/1.1286597 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 346NR UT WOS:000088878400010 ER PT J AU Mikheev, VB Laulainen, NS Barlow, SE Knott, M Ford, IJ AF Mikheev, VB Laulainen, NS Barlow, SE Knott, M Ford, IJ TI The laminar flow tube reactor as a quantitative tool for nucleation studies: Experimental results and theoretical analysis of homogeneous nucleation of dibutylphthalate SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIFFUSION CHAMBER; VAPOR; RATES; NUCLEUS; WATER; CLUSTERS; WORK; SIZE AB A laminar flow tube reactor was designed and constructed to provide an accurate, quantitative measurement of a nucleation rate as a function of supersaturation and temperature. Measurements of nucleation of a supersaturated vapor of dibutylphthalate have been made for the temperature range from -30.3 to +19.1 degrees C. A thorough analysis of the possible sources of experimental uncertainties (such as defining the correct value of the initial vapor concentration, temperature boundary conditions on the reactor walls, accuracy of the calculations of the thermodynamic parameters of the nucleation zone, and particle concentration measurement) is given. Both isothermal and the isobaric nucleation rates were measured. The experimental data obtained were compared with the measurements of other experimental groups and with theoretical predictions made on the basis of the self-consistency correction nucleation theory. Theoretical analysis, based on the first and the second nucleation theorems, is also presented. The critical cluster size and the excess of internal energy of the critical cluster are obtained. (C) 2000 American Institute of Physics. [S0021-9606(00)51133-7]. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. RP Pacific NW Natl Lab, Richland, WA 99352 USA. NR 28 TC 26 Z9 26 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 2000 VL 113 IS 9 BP 3704 EP 3718 AR PII [S0021-9606(00)51133-7] DI 10.1063/1.1287598 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 346NR UT WOS:000088878400027 ER PT J AU Yang, CS Kauzlarich, SM Wang, YC Lee, HWH AF Yang, CS Kauzlarich, SM Wang, YC Lee, HWH TI Photoluminescence as a function of aggregated size from n-butyl-terminated silicon nanoclusters SO JOURNAL OF CLUSTER SCIENCE LA English DT Article; Proceedings Paper CT 2nd Annual Southern Illinois Materials Chemistry Conference CY OCT 21-24, 1999 CL CARBONDALE, IL DE silicon nanoparticles; nanoclusters; photoluminescence; TEM ID POROUS SILICON; NANOCRYSTALS; EMISSION; ROUTE AB Photoluminescence (PL) from alkyl-terminated silicon nanocrystallites as a function of size has been studied. Ultraviolet-blue luminescence (390-410 nm) is observed from as-prepared silicon nanoclusters with diameters From 3 to 8 nm. After 1 h of annealing at 162 degreesC in 2-methoxyethyl ether (diglyme), the lambda (max) of PL shifts from 360 to 420 nm. High-resolution transmission electron microscopy (HRTEM) images show that individual silicon nanoparticles are fused to form pairs of nanoparticles. FTIR spectra show that the alkyl groups remain on the surface of silicon nanoparticles. As the temperature is raised to 250 degreesC for 1 h, the PL no longer shows any peak in the visible light region. TEM images show that the silicon nanoparticles are aggregated and Fused uniformly in one single dimension. to form a strip. and these strips parallel each other. When the temperature is raised to 350 degreesC these silicon nanoparticles form a large piece of silicon textile network, showing that functionalized alkyl surface does not persist above this temperature. A strong Si-O-Si asymmetric stretching vibration appears between 1000 and 1100 cm(-1) at the expense of the: C-W vibrational modes and there is no more change after 3 h of annealing at 250 or 350 degreesC. These: results provide strong evidence that the PL originates from quantum continement. C1 Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Kauzlarich, SM (reprint author), Univ Calif Davis, Dept Chem, 1 Shields Ave, Davis, CA 95616 USA. EM smkauzlarich@ucdavis.edu NR 19 TC 21 Z9 21 U1 0 U2 8 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1040-7278 J9 J CLUST SCI JI J. Clust. Sci. PD SEP PY 2000 VL 11 IS 3 BP 423 EP 431 DI 10.1023/A:1009099416195 PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 369EA UT WOS:000165052000003 ER PT J AU Zhang, YH Gong, XY Zhang, HM Larock, RC Yeung, ES AF Zhang, YH Gong, XY Zhang, HM Larock, RC Yeung, ES TI Combinatorial screening of homogeneous catalysis and reaction optimization based on multiplexed capillary electrophoresis SO JOURNAL OF COMBINATORIAL CHEMISTRY LA English DT Article ID MASS-SPECTROMETRY; THROUGHPUT; LIBRARIES; DISCOVERY; LIGANDS; DESIGN; ASSAY; HPLC C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Yeung, ES (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 32 TC 39 Z9 39 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-4766 J9 J COMB CHEM JI J. Comb. Chem. PD SEP-OCT PY 2000 VL 2 IS 5 BP 450 EP 452 DI 10.1021/cc000043b PG 3 WC Chemistry, Applied; Chemistry, Medicinal; Chemistry, Multidisciplinary SC Chemistry; Pharmacology & Pharmacy GA 355PB UT WOS:000089393100007 ER PT J AU Hyman, JM Li, ST Knupp, P Shashkov, M AF Hyman, JM Li, ST Knupp, P Shashkov, M TI An algorithm for aligning a quadrilateral grid with internal boundaries SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID DIRECTIONAL CONTROL; MAXWELL EQUATIONS; GENERATION AB We present a new numerical algorithm that aligns a quadrilateral grid with internal alignment curves (IACs). These IACs can he used to delineate internal interfaces, discontinuities in material properties, internal boundaries, or major features of a flow field. The adaptive IAC grid generation algorithm readjusts a predefined reference grid to create a nearby grid where the mesh cell edges are aligned with the IACs, On an aligned grid, numerical discretizations of partial differential equations can be formulated to satisfy the interfacial relations, such as matching fluxes across the discontinuity, to reduce the numerical errors introduced by the discontinuity. We present examples to demonstrate the effectiveness of the IAC grid generation algorithm for multiple embedded interfaces in a quadrilateral grid. (C) 2000 Academic Press. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Santa Barbara, Dept Comp Sci, Santa Barbara, CA 93106 USA. Sandia Natl Labs, Parallel Comp Sci Dept, Albuquerque, NM 87185 USA. RP Hyman, JM (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Mail Stop B284, Los Alamos, NM 87545 USA. NR 24 TC 5 Z9 6 U1 2 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 1 PY 2000 VL 163 IS 1 BP 133 EP 149 DI 10.1006/jcph.2000.6560 PG 17 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 350CQ UT WOS:000089083500007 ER PT J AU Knoll, DA Mousseau, VA AF Knoll, DA Mousseau, VA TI On Newton-Krylov multigrid methods for the incompressible Navier-Stokes equations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Knoll, DA (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, MS B216, Los Alamos, NM 87545 USA. NR 13 TC 23 Z9 25 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 1 PY 2000 VL 163 IS 1 BP 262 EP 267 DI 10.1006/jcph.2000.6561 PG 6 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 350CQ UT WOS:000089083500012 ER PT J AU Hubbard, SS Rubin, Y AF Hubbard, SS Rubin, Y TI Hydrogeological parameter estimation using geophysical data: a review of selected techniques SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article; Proceedings Paper CT IAH Groundwater Quality 1998 Conference (GQ98) CY 1998 CL TUBINGEN, GERMANY DE hydrogeological parameter estimation; geophysical data; subsurface measurements ID GROUND-PENETRATING-RADAR; CLAY CONTENT; WATER-MOVEMENT; SEISMIC DATA; PERMEABILITY; TOMOGRAPHY; POROSITY; AQUIFER; SCALE; VELOCITIES AB Subsurface environmental, engineering, and agricultural investigations often require characterization of hydraulic parameters. For example, groundwater flow modeling is often performed through an aquifer whose hydrological properties have been created using stochastic simulation techniques; these techniques use as input both hydraulic parameter point values and spatial correlation structure information. Conventional sampling or borehole techniques for measuring these parameters are costly, time-consuming, and invasive. Geophysical data can compliment direct characterization data by providing multi-dimensional and high resolution subsurface measurements in a minimally invasive manner. Several techniques have been developed in the preceding decade for using joint geophysical-hydrological data to characterize the subsurface; the purpose of this study is to review three methodologies that we have recently developed for use with geophysical-hydrological data to estimate hydrological parameters and their spatial correlation structures. The first two methodologies presented focus on producing high-resolution estimates of hydrological properties using densely sampled geophysical data and limited borehole data. Although we find that high-resolution geophysical data are useful for obtaining these estimates, in practice, geophysical profiles often sample only a small portion of the aquifer under investigation, and thus, the estimates obtained from geophysical data may not be sufficient to completely describe the hydraulic properties of the aquifer volume. The third and last section focuses on using high-resolution tomographic data together with limited borehole data to infer the spatial correlation structure of log-permeability, which can be used within stochastic simulation techniques to generate parameter estimates at unsampled locations. Our synthetic case studies suggest that collection of a few tomographic profiles and interpretation of these profiles together with limited wellbore data can yield hydrological point Values and spatial correlation structure information that can be used to aid numerical aquifer model construction, calibration, and flow simulation As this information is typically only obtainable from extensive hydrological sampling, use of geophysical methods may offer a more efficient and less invasive approach than traditional characterization campaigns. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. RP Hubbard, SS (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. RI Hubbard, Susan/E-9508-2010 NR 54 TC 74 Z9 75 U1 1 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD SEP PY 2000 VL 45 IS 1-2 BP 3 EP 34 DI 10.1016/S0169-7722(00)00117-0 PG 32 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 360DQ UT WOS:000089651500002 ER PT J AU Benamara, M Liliental-Weber, Z Kellermann, S Swider, W Washburn, J Mazur, J Bourret-Courchesne, ED AF Benamara, M Liliental-Weber, Z Kellermann, S Swider, W Washburn, J Mazur, J Bourret-Courchesne, ED TI Study of high-quality GaN grown by OMVPE using an intermediate layer SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE GaN; TEM; OMVPE ID BUFFER LAYER AB The crystalline quality of heteroepitaxial GaN can be significantly improved if the threading dislocations originating from the interface are not allowed to reach the layer surface where they can propagate to the active device areas and act as harmful defects. Incorporation of an intermediate layer grown at low temperature has been shown to limit this defect propagation. This method has been proved to be effective but several interlayers have been required in order to reach dislocation density lower than 10(9)/cm(2). In this priority communication, we report on high-quality GaN layers grown with the use of only one intermediate layer. The defect analysis shows that the density of dislocation is only 8 x 10(7)/cm(2), compared to over 10(10)/cm(2) for layers grown without the intermediate layer. Electron microscopy on cross-section samples shows that deposition under certain low-temperature conditions directly benefits the quality of the subsequently deposited GaN layer. The growth of the GaN top layer appears to be similar to growth observed for lateral epitaxial overgrowth layers. This observation opens the possibility for using standard GaN growth methods to achieve a dislocation density comparable to that achieved with lateral overgrowth epitaxy. Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Benamara, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 62-203, Berkeley, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 10 TC 18 Z9 18 U1 3 U2 7 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 SEP PY 2000 VL 218 IS 2-4 BP 447 EP 450 DI 10.1016/S0022-0248(00)00568-6 PG 4 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 358UH UT WOS:000089575200039 ER PT J AU Cartwright, DC Brunger, MJ Campbell, L Mojarrabi, B Teubner, PJO AF Cartwright, DC Brunger, MJ Campbell, L Mojarrabi, B Teubner, PJO TI Nitric oxide excited under auroral conditions: Excited state densities and band emissions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTRON-IMPACT EXCITATION; CROSS-SECTIONS; VIBRATIONAL-RELAXATION; LOWER THERMOSPHERE; RADIATIVE LIFETIME; TRANSITION-MOMENT; LIMB RADIANCE; DIPOLE-MOMENT; NO; COEFFICIENTS AB Electron impact excitation of vibrational levels in the ground electronic state and nine excited electronic states in NO has been simulated for an IBC II aurora (i.e., similar to 10 kR in 3914 Angstrom radiation) in ol der to predict NO excited state number densities and band emission intensities. New integral electron impact excitation cross sections for NO were combined with a measured IBC II auroral secondary electron distribution, and the vibrational populations of 10 NO electronic states were determined under conditions of statistical equilibrium. This model predicts an extended vibrational distribution in the NO ground electronic state produced by radiative cascade from the seven higher-lying doublet excited electronic states populated by electron impact. In addition to significant energy storage in vibrational excitation of the ground electronic state, both the a (4)Pi L(2)Phi excited electronic states are predicted to have relatively high number densities because they are only weakly connected to lower electronic stales by radiative decay. Fundamental mode radiative transitions involving the lowest nine excited vibrational levels in the ground electronic state are predicted to produce infrared (IR) radiation from 5.33 to 6.05 mu m with greater intensity than any single NO electronic emission band. Fundamental mode radiative transitions within the a (4)Pi, electronic state, in the 10.08-11.37 mu m region, are predicted to have IR intensities comparable to individual electronic emission bands in the Heath and epsilon band systems. Results from this model quantitatively predict the vibrational quantum number dependence of the NO IR measurements of Espy et al. [1988]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Flinders Univ S Australia, Dept Phys, Adelaide, SA 5001, Australia. RP Cartwright, DC (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, POB 1663,DDT MS B297, Los Alamos, NM 87545 USA. NR 48 TC 18 Z9 18 U1 3 U2 11 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 SEP 1 PY 2000 VL 105 IS A9 BP 20857 EP 20867 DI 10.1029/1999JA000333 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356GU UT WOS:000089436200002 ER PT J AU Gary, SP Yin, L Winske, D Reisenfeld, DB AF Gary, SP Yin, L Winske, D Reisenfeld, DB TI Alpha/proton magnetosonic instability in the solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTROMAGNETIC PROTON/PROTON INSTABILITIES; CYCLOTRON-RESONANCE; ACCELERATION; PROTONS; IONS; TEMPERATURE; 0.3-AU; 1-AU AB The average relative flow velocity between protons and alpha particles in collisionless plasmas can excite several distinct alpha/proton instabilities. Here linear theory and two-dimensional hybrid simulations in a homogeneous plasma model are used to study one such mode, the alpha/proton magnetosonic instability, using plasma parameters characteristic of the high-speed solar wind observed by the Ulysses spacecraft at high heliospheric latitudes. Wave-particle scattering by enhanced fluctuations from this mode reduces the alpha/proton relative speed and heats the alphas more strongly than the protons. Post-saturation results for the alpha/proton flow in the simulations are approximately bounded by the linear theory threshold condition for onset of the magnetosonic instability, which is also a statistical upper bound on the alpha/proton relative speed at high beta(p) for some of the Ulysses observations. Thus it is likely that this instability is a constraining agent for the alpha/proton relative speed in some domains of the solar wind. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gary, SP (reprint author), Univ Calif Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. RI Reisenfeld, Daniel/F-7614-2015 NR 28 TC 28 Z9 28 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 SEP 1 PY 2000 VL 105 IS A9 BP 20989 EP 20996 DI 10.1029/2000JA000049 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356GU UT WOS:000089436200012 ER PT J AU Fairfield, DH Otto, A Mukai, T Kokubun, S Lepping, RP Steinberg, JT Lazarus, AJ Yamamoto, T AF Fairfield, DH Otto, A Mukai, T Kokubun, S Lepping, RP Steinberg, JT Lazarus, AJ Yamamoto, T TI Geotail observations of the Kelvin-Helmholtz instability at the equatorial magnetotail boundary for parallel northward fields SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NEAR-EARTH MAGNETOTAIL; INTERPLANETARY MAGNETIC-FIELD; AURORAL BRIGHT SPOTS; MAGNETOSPHERIC BOUNDARY; PLASMA VORTICES; MAGNETOPAUSE; LAYER; SURFACE; DAYSIDE; FLANKS AB For several hours on March 24, 1995, the Geotail spacecraft remained near the duskside magnetotail boundary some 15 R-E behind the Earth while the solar wind remained very quiet (V=330 km s(-1), n=14-21 cm(-3)) with a very steady 11-nT northward magnetic field. Geotail experienced multiple crossings of a boundary between a dense (n=19 cm(-3)), cool (T-p=40 eV), rapidly flowing (V=310 km s(-1)) magnetosheath plasma and an interior region characterized by slower tailward velocities (V=100 km s(-1)), lower but substantial densities (n=3 cm(-3)) and somewhat hotter ions (220 eV). The crossings recurred with a roughly 3-min periodicity, and all quantities were highly variable in the boundary region. The magnetic field, in fact, exhibited some of the largest fluctuations seen anywhere in space, despite the fact that the exterior magnetosheath field and the interior magnetosphere field were both very northward and nearly parallel. On the basis of an MHD simulation of this event, we argue that the multiple crossings are due to a Kelvin-Helmholtz instability at the boundary that generates vortices which move past the spacecraft. A determination of boundary normals supports Kelvin-Helmholtz theory in that the nonlinear steepening of the waves is seen on the leading edge of the waves rather than on the trailing edge, as has sometimes been seen in the past. It is concluded that the Kelvin-Helmholtz instability is an important process for transferring energy, momentum and particles to the magnetotail during times of very northward interplanetary magnetic field. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Nagoya Univ, STELAB, Toyokawa 442, Japan. MIT, Space Res Ctr, Cambridge, MA 02139 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Univ Alaska Fairbanks, Inst Geophys, Fairbanks, AK 99775 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Fairfield, DH (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Code 695, Greenbelt, MD 20771 USA. NR 35 TC 166 Z9 169 U1 2 U2 16 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 SEP 1 PY 2000 VL 105 IS A9 BP 21159 EP 21173 DI 10.1029/1999JA000316 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356GU UT WOS:000089436200028 ER PT J AU Dobrescu, BA Matchev, KT AF Dobrescu, BA Matchev, KT TI Light axion within the next-to-minimal Supersymmetric Standard Model SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE Supersymmetric Standard Model; Higgs physics ID HIGGS-BOSON MASSES; GAUGE SINGLET; WEAK-SCALE; EXPERIMENTAL CONSTRAINTS; RADIATIVE-CORRECTIONS; PARTICLE SPECTRUM; SYMMETRY-BREAKING; TAN-BETA; Z-DECAYS; PHENOMENOLOGY AB We analyze the Higgs sector in the next-to-minimal Supersymmetric Standard Model, emphasizing the possibility of a light CP-odd scalar (axion) in the spectrum. We compute the coupling of the Standard-Model-like Higgs boson to a pair of axions, and show that it can be large enough to modify the Higgs branching fractions, with a significant impact on the Higgs searches. We delineate the range of parameters relevant for this scenario, and also derive analytic expressions for the scalar masses and couplings in two special cases - a decoupling limit where all scalars other than the axion are heavier than the Standard-Model-like Higgs boson, and the large tan beta limit. C1 Fermilab Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP Dobrescu, BA (reprint author), Fermilab Natl Accelerator Lab, Dept Theoret Phys, POB 500, Batavia, IL 60510 USA. EM bdob@fnal.gov; matchev@fnal.gov NR 81 TC 115 Z9 115 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD SEP PY 2000 IS 9 AR 031 PG 27 WC Physics, Particles & Fields SC Physics GA 423DT UT WOS:000168160700031 ER PT J AU Kaplan, DE Kribs, GD AF Kaplan, DE Kribs, GD TI Gaugino-assisted anomaly mediation SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE supersymmetry breaking; supersymmetric standard model ID DYNAMICAL SUPERSYMMETRY BREAKING; ART. NO. 095004; PHENOMENOLOGICAL IMPLICATIONS; EXTRA DIMENSIONS; STANDARD MODEL; SUSY BREAKING; SUPERGRAVITY; RENORMALIZATION; EXTENSIONS; DEGENERACY AB We present a model of supersymmetry breaking mediated through a small extra dimension. Standard model matter multiplets and a supersymmetry-breaking (or "hidden") sector are confined to opposite four-dimensional boundaries while gauge multiplets live in the bulk. The hidden sector does not contain a singlet and the dominant contribution to gaugino masses is via anomaly-mediated supersymmetry breaking. Scalar masses get contributions from both anomaly mediation and a tiny hard breaking of supersymmetry by operators on the hidden-sector boundary. These operators contribute to scalar masses at one loop and in most of parameter space, their contribution dominates. Thus it is easy to make all squared scalar masses positive. As no additional fields or symmetries are required below the Planck scale, we consider this the simplest working model of anomaly mediation. The gaugino spectrum is left untouched and the phenomenology of the model is roughly similar to anomaly mediated supersymmetry breaking with a universal scalar mass added. We identify the main differences in the spectrum between this model and other approaches. We also discuss mechanisms for generating the mu term and constraints on additional bulk fields. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. RP Argonne Natl Lab, Div High Energy Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. EM dkaplan@theory.uchicago.edu; kribs@pheno.physics.wisc.edu NR 60 TC 63 Z9 63 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD SEP PY 2000 IS 9 AR 048 PG 27 WC Physics, Particles & Fields SC Physics GA 423DT UT WOS:000168160700048 ER PT J AU Konechny, A Schwarz, A AF Konechny, A Schwarz, A TI Moduli spaces of maximally supersymmetric solutions on non-commutative tori and non-commutative orbifolds SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE M(atrix) theories; non-commutative geometry; string duality ID BACKGROUND B-FIELD; NONCOMMUTATIVE TORI; PROJECTIVE-MODULES; MORITA EQUIVALENCE; MATRIX-THEORY; BPS STATES; D-BRANE; DUALITY; MODEL; TORONS AB A maximally supersymmetric configuration of super Yang-Mills living on a non-commutative torus corresponds to a constant curvature connection. On a non-commutative toroidal orbifold there is an additional constraint that the connection be equivariant. We study moduli spaces of (equivariant) constant curvature connections on non-commutative even-dimensional tori and on toroidal orbifolds. As an illustration we work out the cases of Z(2) and Z(4) orbifolds in detail. The results we obtain agree with a commutative picture describing systems of branes wrapped on cycles of the torus and branes stuck at exceptional orbifold points. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Math, Davis, CA 95616 USA. RP Univ Calif Berkeley, Dept Phys, Mail Stop 50A-5101, Berkeley, CA 94720 USA. EM konechny@thsrv.lbl.gov; schwarz@math.ucdavis.edu NR 34 TC 14 Z9 14 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD SEP PY 2000 IS 9 AR 005 PG 24 WC Physics, Particles & Fields SC Physics GA 423DT UT WOS:000168160700005 ER PT J AU Lykken, J Wang, J Myers, RC AF Lykken, J Wang, J Myers, RC TI Gravity in a box SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE extra large dimensions; classical theories of gravity ID EXTRA DIMENSIONS; METASTABLE GRAVITONS; INFINITELY LARGE; DOMAIN-WALLS; BRANE WORLD; COMPACTIFICATION; HIERARCHY; TEV; MILLIMETER; COSMOLOGY AB We consider a brane-world construction which incorporates a finite region of at space, "the box", surrounded by a region of anti-de Sitter space. This hybrid construction provides a framework which interpolates between the scenario proposed by Arkani-Hamed, Dimopoulos and Dvali, and that proposed by Randall and Sundrum. Within this composite framework, we investigate the effects of resonant modes on four-dimensional gravity. We also show that, on a probe brane in the anti-de Sitter region, there is enhanced production of on-shell nonresonant modes. We compare our model to some recent attempts to incorporate the Randall-Sundrum scenario into superstring theory. C1 Fermilab Natl Accelerator Lab, Thery Dept, Batavia, IL 60510 USA. McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. RP Lykken, J (reprint author), Fermilab Natl Accelerator Lab, Thery Dept, POB 500, Batavia, IL 60510 USA. EM jingw@fnal.gov; rcm@hep.physics.mcgill.ca NR 38 TC 19 Z9 19 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD SEP PY 2000 IS 9 AR 009 PG 18 WC Physics, Particles & Fields SC Physics GA 423DT UT WOS:000168160700009 ER PT J AU Shukla, AK Futrell, JH AF Shukla, AK Futrell, JH TI Tandem mass spectrometry: dissociation of ions by collisional activation SO JOURNAL OF MASS SPECTROMETRY LA English DT Review DE tandem mass spectrometry; ion dissociation; collisional activation ID SURFACE-INDUCED DISSOCIATION; ASSEMBLED MONOLAYER FILMS; ACETONE MOLECULAR ION; LOW-ENERGY COLLISIONS; LIVED EXCITED-STATE; TRANSLATIONAL ENERGY; POLYATOMIC IONS; PROTONATED PEPTIDES; REACTIVE COLLISIONS; BEAM AB This review presents a brief historical introduction to the development of tandem mass spectrometry and its principal applications. It is placed in the context of the general principles underlying mass spectrometry, particularly the relationships between internal energy and fragmentation kinetics. The center-of-mass framework is presented as a convenient means of applying conservation of momentum to the energy transfer problem in tandem mass spectrometry as a means of deducing energy transfer in the collisional activation step and kinetic energy release as activated ions dissociate into fragment ions and neutrals, The principles of molecular beam methods are summarized and illustrative examples are given for which definitive information on reaction dynamics is available. The importance of scattering-very little appreciated in early discussions of tandem mass spectrometry-is shown to be the natural consequence of impulsive collisions, which appears to be a general mechanism for energy exchange in collisional activation. It is shown that the average energy transferred in single collisions is much less than the theoretical maximum given by the center-of-mass collision energy and the Massey criterion is presented as a simplistic rationale for understanding the essentially exponential decline in the energy transfer function above and below the relative velocity at which the probability for energy transfer is maximized, The issues of energy transfer in collisions of large molecular ions with low-mass neutrals are reviewed and a general description of energy transfer in multiple collisions is presented. It is shown that the center-of-mass and Massey criterion limitations are pragmatically overcome bai multiple collision activation in ion traps, Surface-induced dissociation is presented as a viable alternative to multiple collision activation which is especially attractive for activation of large molecular ions. Finally, a few of the emerging dynamics principles governing energy transfer and dissociation of peptides are summarized. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Pacific NW Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. RP Pacific NW Natl Lab, Environm & Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 120 TC 148 Z9 150 U1 6 U2 72 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1076-5174 EI 1096-9888 J9 J MASS SPECTROM JI J. Mass Spectrom. PD SEP PY 2000 VL 35 IS 9 BP 1069 EP 1090 DI 10.1002/1096-9888(200009)35:9<1069::AID-JMS54>3.0.CO;2-C PG 22 WC Biochemical Research Methods; Chemistry, Analytical; Spectroscopy SC Biochemistry & Molecular Biology; Chemistry; Spectroscopy GA 360LD UT WOS:000089668400001 ER PT J AU Lang, CI Sordelet, DJ Besser, MF Shechtman, D Biancaniello, FS Gonzalez, EJ AF Lang, CI Sordelet, DJ Besser, MF Shechtman, D Biancaniello, FS Gonzalez, EJ TI Quasicrystalline coatings: Thermal evolution of structure and properties SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID AL-PD-MN; QUASI-CRYSTALLINE COATINGS; ICOSAHEDRAL PHASE; FE; ALLOYS; SYSTEM; CONDUCTIVITY; DIAGRAM; STATE; ORDER AB Quasicrystals (QCs) are known to exhibit unique properties as a result of their unique quasiperiodic structure. Real quasicrystalline (QC) materials, however, may exhibit complex phase structures, and as a consequence, their properties may differ from expectations. In the present work, QC coatings of the Al-Cu-Fe, Al-Cu-Fe-Cr, and Al-Pd-Mn systems were prepared by a plasma spray process, followed by heat treatments in the range 500-800 degrees C. The phase structure and evolution of the coatings were evaluated, and thermal diffusivity, hardness, and friction coefficient were measured. The presence of quasicrystalline and crystalline phases and their influence on these properties is systematically considered for the first time. Broadly, the coatings exhibit the properties expected of QC materials, low thermal diffusivity, high hardness, and low coefficients of friction, but it is also shown that these properties can be sensitive to the phase structure of the coatings. This suggests that phase structure may be manipulated by heat treatment to optimize the properties of QC coatings. C1 Univ Cape Town, Dept Mat Engn, ZA-7700 Rondebosch, South Africa. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Mech Engn, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Technion Israel Inst Technol, Dept Mat Engn, IL-32000 Haifa, Israel. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Met, Gaithersburg, MD 20899 USA. RP Lang, CI (reprint author), Univ Cape Town, Dept Mat Engn, ZA-7700 Rondebosch, South Africa. NR 41 TC 11 Z9 11 U1 3 U2 14 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 SEP PY 2000 VL 15 IS 9 BP 1894 EP 1904 DI 10.1557/JMR.2000.0275 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA 350QN UT WOS:000089112800009 ER PT J AU Edman, L Ferry, A Doeff, MM AF Edman, L Ferry, A Doeff, MM TI Slow recrystallization in the polymer electrolyte system poly(ethylene oxide)(n)-LiN(CF3SO2)(2) SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CONDUCTIVITY BEHAVIOR; RUBBERY ELECTROLYTES; PHASE-DIAGRAMS; OXIDE); LICF3SO3 AB Thermal and ion-transport properties of the salt-in-polymer system poly(ethylene oxide)(n)-LiN(CF3SO2)(2) [P(EO)(n)LiTFSI] were investigated for compositions ranging from n =5 to n = 50. Particular attention was paid to the region n = 8 to 10 where a crystallinity gap previously had been reported. We concluded that the absence of distinct melting transitions for salt-rich compositions (n = 5 to 12) was attributable to the extremely slow kinetics of recrystallization of this system following a heat treatment. The results further indicated that it was primarily the nucleation process that was inhibited by the [(bis)trifluoromethanesulfonate imide] (TFSI) anion. As a corollary, the ionic conductivity was strongly dependent on the thermal history of samples, and an enhancement of up to 300% was observed in the; ambient temperature ionic conductivity for pre-heated salt-rich samples. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Monash Univ, Dept Mat Engn, Clayton, Vic 3168, Australia. RP Edman, L (reprint author), Umea Univ, Dept Expt Phys, S-90187 Umea, Sweden. EM ludvig.edman@physics.umu.se NR 22 TC 85 Z9 85 U1 4 U2 39 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 SEP PY 2000 VL 15 IS 9 BP 1950 EP 1954 DI 10.1557/JMR.2000.0281 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA 350QN UT WOS:000089112800015 ER PT J AU Koritala, RE Lanagan, MT Chen, N Bai, GR Huang, Y Streiffer, SK AF Koritala, RE Lanagan, MT Chen, N Bai, GR Huang, Y Streiffer, SK TI Microstructure and properties of PbZr0.6Ti0.4O3 and PbZrO3 thin films deposited on template layers SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ELECTRICAL-PROPERTIES; BUFFER LAYER; ORIENTATION; CAPACITORS; PBTIO3; MOCVD; (PB AB Polycrystalline Pb(ZrxTi1-x)O-3 thin films with x = 0.6 and 1.0 were deposited at low temperatures (450-525 degrees C) on (111)Pt/Ti/SiO2/Si substrates by metalorganic chemical vapor deposition. The films were characterized by x-ray diffraction, electron microscopy, and electrical measurements. The texture of the films could be improved by using one of two template layers: PbTiO3 or TiO2. Electrical properties, including dielectric constants, loss tangents, polarization, coercive field, and breakdown field, were also examined. PbZrO3 films on Pt/Ti/SiO2/Si with a pseudocubic (110) orientation exhibited an electric-field-induced transformation from the antiferroelectric phase to the ferroelectric phase. The effect of varying processing conditions on the microstructure and electrical properties of the films is discussed. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Koritala, RE (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Streiffer, Stephen/A-1756-2009; Koritala, Rachel/F-1774-2011 NR 35 TC 9 Z9 9 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 2000 VL 15 IS 9 BP 1962 EP 1971 DI 10.1557/JMR.2000.0283 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 350QN UT WOS:000089112800017 ER PT J AU Karabulut, M Marasinghe, GK Ray, CS Day, DE Waddill, GD Allen, PG Booth, CH Bucher, JJ Caulder, DL Shuh, DK Grimsditch, M Saboungi, ML AF Karabulut, M Marasinghe, GK Ray, CS Day, DE Waddill, GD Allen, PG Booth, CH Bucher, JJ Caulder, DL Shuh, DK Grimsditch, M Saboungi, ML TI Local environment of iron and uranium ions in vitrified iron phosphate glasses studied by FeK and U L-III-edge x-ray absorption fine structure spectroscopy SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID NUCLEAR WASTE; PRE-EDGE; SPECTRA; PHOTOELECTRON; COORDINATION; COMPLEXES; RELEVANT; EXAFS AB The local structure of iron and uranium ions in a series of iron phosphate glasses with the general composition (40 - x)Fe2O3-xUO(2)-60P(2)O(5) and (1-x-y) (40Fe(2)O(3)-60P(2)O(5))-xUO(2)-y(Na2O or CaO) was investigated using Fe K-edge and U L-III-edge x-ray absorption fine structure spectroscopy. Replacing Fe2O3 by UO2 in the glass caused more distortion in the coordination environment of Fe(III) ions. Extended x-ray absorption fine structure fits revealed that the Fe-P bonds observed in the base glass also existed in all the waste-loaded glasses. X-ray absorption near-edge structure showed that the uranium ions were predominantly present as U(IV) in the glasses. Uranium ions were coordinated to approximately 8 +/- 1 oxygen atoms and 2.5 +/- 0.6 phosphorus atoms at an average distance of 2.47 +/- 0.02 and 3.8 +/- 0.02 Angstrom, respectively. There were no Fe-U or U-Fe neighbors observed, indicating that uranium ions occupied voids in the glass away from the PO4 units. These conclusions were supported by Mossbauer, x-ray photoelectron, and Raman spectroscopic data. C1 Univ Missouri, Grad Ctr Mat Res, Rolla, MO 65409 USA. Univ Missouri, Dept Phys, Rolla, MO 65409 USA. Univ Kafkas, Dept Phys, Kars, Turkey. Univ Calif Lawrence Livermore Natl Lab, Anal & Nucl Chem Div, Livermore, CA 94551 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Glennn T Seaborg Ctr, Berkeley, CA 94720 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Karabulut, M (reprint author), Univ Missouri, Grad Ctr Mat Res, 1870 Miner Circle, Rolla, MO 65409 USA. RI Saboungi, Marie-Louise/C-5920-2013; Booth, Corwin/A-7877-2008 OI Saboungi, Marie-Louise/0000-0002-0607-4815; NR 35 TC 26 Z9 26 U1 0 U2 11 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 SEP PY 2000 VL 15 IS 9 BP 1972 EP 1984 DI 10.1557/JMR.2000.0284 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 350QN UT WOS:000089112800018 ER PT J AU Lagow, BW Robertson, IM Rehn, LE Baldo, PM Coleman, JJ Yeoh, TS AF Lagow, BW Robertson, IM Rehn, LE Baldo, PM Coleman, JJ Yeoh, TS TI Compositional variation of microstructure in ion-implanted AlxGa1-xAs SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID AMORPHIZATION MECHANISMS; DAMAGE BUILDUP; GAAS; HETEROSTRUCTURES; ALAS; SUPERLATTICES; IRRADIATION; DEPENDENCE AB The ion damage produced in alloys of AlxGa1-xAs (x = 0.6, 0.7, 0.8, and 0.85) by implantation at 77 K with Kr ions (500, 700, and 1500 keV) was studied by using Rutherford backscattering channeling and transmission electron microscopy, In addition, the accumulation of ion damage at 50 K was studied by performing the ion implantations in situ in the transmission electron microscope. In Al0.8Ga0.2As, damage accumulation at 77 K was independent of dose rate, indicating that dynamic annealing is not occurring at 77 K, The in situ studies demonstrated that planar defects are produced on warm-up from 50 K to room temperature, indicating that they are not the nucleation site for amorphization. The lower energy implantations revealed that amorphization initiated within the AlxGa1-xAs layer, showing that heterointerfaces are not required for amorphization. These results, along with the similarity of the room-temperature microstructures in the different alloys, imply that the amorphization mechanism is independent of Al content. It is proposed that the observed dependence of the amorphization dose on Al content is related to an increase in the number of cascade overlaps needed to initiate and to produce a continuous amorphous layer. A mechanism explaining the microstructural changes with composition, based on the thermal and physical properties of the alloy and on the distribution of energetic cascade events, is presented. C1 Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA. RP Lagow, BW (reprint author), Univ Illinois, Dept Mat Sci & Engn, 1304 W Green St, Urbana, IL 61801 USA. RI Coleman, James/C-9703-2011 NR 25 TC 3 Z9 3 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 2000 VL 15 IS 9 BP 2043 EP 2053 DI 10.1557/JMR.2000.0293 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA 350QN UT WOS:000089112800027 ER PT J AU Alma, MH Kelley, SS Bektas, I AF Alma, MH Kelley, SS Bektas, I TI The tensile properties of molding products obtained by the condensation of various tree barks and phenol by using sulfuric acid as a catalyst SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID WOOD; RESIN C1 Kahramanmaras Sutcu Imam Univ, Dept Ind Engn Forestry, TR-46060 K Maras, Turkey. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Alma, MH (reprint author), Kahramanmaras Sutcu Imam Univ, Dept Ind Engn Forestry, TR-46060 K Maras, Turkey. NR 12 TC 7 Z9 8 U1 1 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD SEP PY 2000 VL 19 IS 17 BP 1517 EP 1520 DI 10.1023/A:1006704501712 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 349NZ UT WOS:000089053700007 ER PT J AU Faber, V Wing, GM Zahrt, J AF Faber, V Wing, GM Zahrt, J TI Meta-tomography SO JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Wing, GM (reprint author), 302 Calle Estado, Santa Fe, NM 87501 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-247X J9 J MATH ANAL APPL JI J. Math. Anal. Appl. PD SEP 1 PY 2000 VL 249 IS 1 BP 95 EP 117 DI 10.1006/jmaa.2000.6930 PG 23 WC Mathematics, Applied; Mathematics SC Mathematics GA 351TH UT WOS:000089173900006 ER PT J AU Wilson, MA Brunger, AT AF Wilson, MA Brunger, AT TI The 1.0 angstrom crystal structure of Ca2+-bound calmodulin: an analysis of disorder and implications for functionally relevant plasticity SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE calmodulin; X-ray crystallography; Paramecium tetraurelia; disorder; atomic resolution ID CONFORMATIONAL DYNAMICS; STRUCTURE REFINEMENT; MOLECULAR-DYNAMICS; PROTEIN STRUCTURES; BACKBONE DYNAMICS; PEPTIDE COMPLEX; THERMAL MOTION; APO-CALMODULIN; RESOLUTION; RECOGNITION AB Calmodulin (CaM) is a highly conserved 17 kDa eukaryotic protein that can bind specifically to over 100 protein targets in response to a Ca2+ signal. Ca2+-CaM requires a considerable degree of structural plasticity to accomplish this physiological role; however, the nature and extent of this plasticity remain poorly characterized. Here, we present the 1.0 Angstrom crystal structure of Paramecium tetraurelia Ca2+-CaM, including 36 discretely disordered residues and a fifth Ca2+ that mediates a crystal contact. The 36 discretely disordered residues are located primarily in the central helix and the two hydrophobic binding pockets, and reveal correlated sidechain disorder that may assist target-specific deformation of the binding pockets. Evidence of domain displacements and discrete backbone disorder is provided by translation-libration-screw (TLS) analysis and multiconformer models of protein disorder, respectively. In total, the evidence for disorder at every accessible length-scale in Ca2+-CaM suggests that the protein occupies a large number of hierarchically arranged conformational substates in the crystalline environment and may sample a quasi-continuous spectrum of conformations in solution. Therefore, we propose that the functionally distinct forms of CaM are less structurally distinct than previously believed, and that the different activities of CaM in response to Ca2+ may result primarily from Ca2+-mediated alterations in the dynamics of the protein. (C) 2000 Academic Press. C1 Stanford Univ, Howard Hughes Med Inst, Stanford, CA 94305 USA. Stanford Univ, Dept Cellular & Mol Physiol, Stanford, CA 94305 USA. Stanford Univ, Dept Neurol, Stanford, CA 94305 USA. Stanford Univ, Dept Neurol Sci, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Brunger, AT (reprint author), Stanford Univ, Howard Hughes Med Inst, Stanford, CA 94305 USA. NR 60 TC 217 Z9 218 U1 2 U2 21 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD SEP 1 PY 2000 VL 301 IS 5 BP 1237 EP 1256 DI 10.1006/jmbi.2000.4029 PG 20 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 353ZD UT WOS:000089304600012 PM 10966818 ER PT J AU Chialvo, AA Cummings, PT Simonson, JM Mesmer, RE AF Chialvo, AA Cummings, PT Simonson, JM Mesmer, RE TI Solvation in high-temperature aqueous electrolyte solutions SO JOURNAL OF MOLECULAR LIQUIDS LA English DT Article; Proceedings Paper CT 5th Liblice Conference on the Statistical Mechanics of Liquids CY JUN 07-12, 1998 CL ZELEZNA RUDA, CZECH REPUBLIC ID INFINITE DILUTION; WATER; SIMULATION; MIXTURES; THERMODYNAMICS; CONSTANT; LICL; NACL; NABR; CSBR AB We review the recently proposed molecular-based formalism for infinitely dilute high-temperature electrolyte solutions which establishes connections between the microscopic solvent environment around individual ionic species and their macroscopic solvation behavior. Then, we illustrate this formalism by interpreting some recent experimental results for infinitely dilute NaCl aqueous solutions. Finally, we discuss some theoretical implications, guided by the formalism, concerning the modeling of high-temperature aqueous-electrolyte solutions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Chialvo, AA (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Cummings, Peter/B-8762-2013; OI Cummings, Peter/0000-0002-9766-2216; Chialvo, Ariel/0000-0002-6091-4563 NR 31 TC 2 Z9 2 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7322 J9 J MOL LIQ JI J. Mol. Liq. PD SEP PY 2000 VL 87 IS 2-3 BP 233 EP 242 DI 10.1016/S0167-7322(00)00123-9 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 353VY UT WOS:000089297200009 ER PT J AU Lowe, TC Bishop, A Burns, C Hartford, A Parkin, D Trewhella, J AF Lowe, Terry C. Bishop, Alan Burns, Carol Hartford, Allen Parkin, Don Trewhella, Jill TI Nanoscale science and technology at Los Alamos National Laboratory SO JOURNAL OF NANOPARTICLE RESEARCH LA English DT Article DE nano-bioscience; nano-devices; nano-fabrication; nanoscale characterization; nanoscale theory; nanostructured materials; nanoscience education; nanoscience strategy; quantum computing AB Research in the emerging field of nanoscale science and technology has grown steadily at Los Alamos National Laboratory since 1990. This article summarizes some of this work, examining research highlights within the seven key categories of nanoscience in which Los Alamos has ongoing projects, capabilities, and facilities: (1) Materials and chemistry, (2) Theory and modeling, (3) Bioscience, (4) Investigative tools and facilities, (5) Sensors and devices, (6) Synthesis and fabrication, and (7) Education and outreach. Future research horizons are indicated throughout while institutional strategies for advancing nanoscale science are summarized at the end. C1 [Lowe, Terry C.; Bishop, Alan; Burns, Carol; Hartford, Allen; Parkin, Don; Trewhella, Jill] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lowe, TC (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM tlowe@lanl.gov OI Trewhella, Jill/0000-0002-8555-6766 NR 106 TC 1 Z9 1 U1 1 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1388-0764 J9 J NANOPART RES JI J. Nanopart. Res. PD SEP PY 2000 VL 2 IS 3 BP 249 EP 266 DI 10.1023/A:1010084920237 PG 18 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA V19IY UT WOS:000208067300003 ER PT J AU McLaughlin, JC Tagg, SL Zwanziger, JW Haeffner, DR Shastri, SD AF McLaughlin, JC Tagg, SL Zwanziger, JW Haeffner, DR Shastri, SD TI The structure of tellurite glass: a combined NMR, neutron diffraction, and X-ray diffraction study SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 9th International Conference on the Physics of Non-Crystalline Solids (PNS 1999) CY OCT 17-21, 1999 CL TUCSON, ARIZONA SP NASA, Div Micrograv Sci & Applicat, NSF, Div Mat Res, Guardian Ind Corp, Elsevier Ltd ID M = LI; NA-23 NMR; CRYSTAL-STRUCTURE; SODIUM TELLURITE; RAMAN-SPECTRA; TEMPERATURE; TETRATELLURITE; ENVIRONMENTS; DITELLURITE; NA2TEO3 AB Models are presented of sodium tellurite glasses in the composition range (Na2O)(x)-(TeO2)(1-x), 0.1 < x < 0.3. The models combine self-consistently data from three different and complementary sources: sodium-23 nuclear magnetic resonance (NMR), neutron diffraction, and X-ray diffraction. The models were generated using the Reverse Monte Carlo algorithm, modified to include NMR data in addition to diffraction data. The presence in the models of all five tellurite polyhedra consistent with the Te4+ oxidation state were found to be necessary to achieve agreement with the data. The distribution of polyhedra among these types varied from a dominance of bridged species at lower sodium contents, to polyhedra with one or zero bridging oxygen at larger sodium contents. The models indicate that the sodium cations themselves form sodium oxide clusters particularly at the x = 0.2 composition. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Zwanziger, JW (reprint author), Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. NR 26 TC 47 Z9 48 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 2000 VL 274 IS 1-3 BP 1 EP 8 DI 10.1016/S0022-3093(00)00199-X PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 353WK UT WOS:000089298300002 ER PT J AU Brow, RK Click, CA Alam, TM AF Brow, RK Click, CA Alam, TM TI Modifier coordination and phosphate glass networks SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 9th International Conference on the Physics of Non-Crystalline Solids (PNS 1999) CY OCT 17-21, 1999 CL TUCSON, AZ SP NASA, Div Micrograv Sci & Applicat, NSF, Div Mat Res, Guardian Ind Corp, Elsevier Ltd ID SHORT-RANGE STRUCTURE; ORDER AB The addition of up to similar to 16 mol% Cs2O to vitreous P2O5 reduces the glass transition temperature (T-g) by 150 K, whereas further additions up to 60 mol% increases T-g by similar to 20 K. P-31 magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra indicate that the phosphate network is progressively depolymerized over the entire range of compositions. The property trend is explained by a transition in the Cst coordination environment, from isolated Cs-polyhedra below similar to 16 mol% Cs2O to a corner-sharing Cs-polyhedral sub-structure in the glasses with greater Cs2O contents. This 'modifier transition' does not occur in Al phosphate glasses. Al-27 MAS NMR spectra indicate that the average Al coordination number decreases with increasing Al2O3 content to avoid the formation of Al-O-Al bonds in these binary phosphate glasses. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Missouri, Dept Ceram Engn, Rolla, MO 65409 USA. Sandia Natl Labs, Organ Mat Dept, Albuquerque, NM 87185 USA. RP Brow, RK (reprint author), Univ Missouri, Dept Ceram Engn, 222 McNutt Hall, Rolla, MO 65409 USA. EM brow@umr.edu NR 29 TC 95 Z9 98 U1 5 U2 24 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 EI 1873-4812 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 2000 VL 274 IS 1-3 BP 9 EP 16 DI 10.1016/S0022-3093(00)00178-2 PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 353WK UT WOS:000089298300003 ER PT J AU Alam, TM AF Alam, TM TI Monte Carlo simulations of phosphate polyhedron connectivity in glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 9th International Conference on the Physics of Non-Crystalline Solids (PNS 1999) CY OCT 17-21, 1999 CL TUCSON, ARIZONA SP NASA, Div Micrograv Sci & Applicat, NSF, Div Mat Res, Guardian Ind Corp, Elsevier Ltd ID SHORT-RANGE STRUCTURE; P-31 MAS NMR; MULTIPLE-QUANTUM NMR; 2D EXCHANGE NMR; SPECTROSCOPY AB Monte Carlo (MC) simulations of phosphate tetrahedron connectivity distributions in alkali and alkaline earth phosphate glasses are reported. By utilizing a discrete bond model, the distribution of next-nearest neighbor connectivities between phosphate polyhedron for random, alternating and clustering bonding scenarios was evaluated as a function of the relative bond energy difference. The simulated distributions are compared to experimentally observed connectivities reported for solid-state two-dimensional (2D) exchange and double-quantum (2Q) nuclear magnetic resonance (NMR) experiments of phosphate glasses. These MC simulations demonstrate that the polyhedron connectivity is best described by a random distribution in lithium phosphate and calcium phosphate glasses. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Alam, TM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 32 TC 7 Z9 7 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 2000 VL 274 IS 1-3 BP 39 EP 49 DI 10.1016/S0022-3093(00)00201-5 PG 11 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 353WK UT WOS:000089298300007 ER PT J AU Hunt, AG AF Hunt, AG TI Fragility of liquids using percolation-based transport theories - Correlation between limiting slope of the viscosity and non-exponentiality of relaxation SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 9th International Conference on the Physics of Non-Crystalline Solids (PNS 1999) CY OCT 17-21, 1999 CL TUCSON, ARIZONA SP NASA, Div Micrograv Sci & Applicat, NSF, Div Mat Res, Guardian Ind Corp, Elsevier Ltd ID GLASS-TRANSITION TEMPERATURE; SUPERCOOLED LIQUIDS; CONFINEMENT; CONDUCTION; BEHAVIOR; MELTS AB Transport in super-cooled liquids becomes increasingly heterogeneous with reduction in temperature. This transport is assumed to occur by thermally activated hopping over barriers. At a temperature defined here to be T-c, transport becomes percolative rather than diffusive, and, especially for mechanical relaxation, larger energy barriers must be surmounted in order to establish steady-state response. Use of the same distribution of energy barriers at high and low temperatures, but different theoretical approaches to calculate transport properties, relates expressions for the viscosity at high and low temperatures. Such an approach also allows calculation here of an expression relating the limiting slope, m, of the viscosity to the parameters of an assumed log-normal distribution of energy barriers. Careful calculation of the frequency dependence of transport properties in terms of this distribution of energy barriers also allows expression of the non-exponentiality parameter, beta, in terms of the same parameters. Analytical calculations of both (within established approximation schemes) allows quantitative comparison between m and beta. The analytical results are evaluated using typical frequencies and times from experiment. Agreement between experiment and calculations is fair. Nevertheless, sensitivity of the calculations to uncertainty in the values of the experimentally derived parameters makes it necessary to view the correspondence with caution. It is tentatively concluded that the major component of the curvature of the viscosity with decreasing temperature is indeed the change in transport type, and not changes in structure. Advances in theory as well as application of numerical methods are needed to help to reduce uncertainty in the conclusions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hunt, AG (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 37 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 2000 VL 274 IS 1-3 BP 93 EP 101 DI 10.1016/S0022-3093(00)00206-4 PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 353WK UT WOS:000089298300015 ER PT J AU Grest, GS Putz, M Everaers, R Kremer, K AF Grest, GS Putz, M Everaers, R Kremer, K TI Stress-strain relation of entangled polymer networks SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 9th International Conference on the Physics of Non-Crystalline Solids (PNS 1999) CY OCT 17-21, 1999 CL TUCSON, ARIZONA SP NASA, Div Micrograv Sci & Applicat, NSF, Div Mat Res, Guardian Ind Corp, Elsevier Ltd ID RUBBER ELASTICITY; CONSTRAINTS; JUNCTIONS; SYSTEMS; MODULUS AB The non-linear stress-strain relation for cross-linked polymer networks is studied using molecular dynamics simulations. Previously we demonstrated the importance of trapped entanglements in determining the elastic and relaxational properties of networks. Here, we present new results for the stress versus strain for both dry and swollen networks. Models which limit the fluctuations of the network strands like the tube model are shown to describe the stress for both elongation and compression. For swollen networks, the total modulus is found to decrease like (V-0/V)(2/3) and goes to the phantom model result only for short strand networks. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Ctr Microengineered Mat, Albuquerque, NM 87106 USA. Max Planck Inst Polymerforsch, D-55021 Mainz, Germany. RP Grest, GS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Kremer, Kurt/G-5652-2011; Everaers, Ralf/K-2228-2013; MPIP, Theory/I-9884-2014 OI Everaers, Ralf/0000-0002-6843-2753; NR 26 TC 42 Z9 42 U1 4 U2 25 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 2000 VL 274 IS 1-3 BP 139 EP 146 DI 10.1016/S0022-3093(00)00224-6 PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 353WK UT WOS:000089298300021 ER PT J AU Magruder, RH Weller, RA Weeks, RA Zuhr, RA Hensley, DK AF Magruder, RH Weller, RA Weeks, RA Zuhr, RA Hensley, DK TI Effects of MeV energy titanium ion implants on the oxygen related defects centers in silica SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 9th International Conference on the Physics of Non-Crystalline Solids (PNS 1999) CY OCT 17-21, 1999 CL TUCSON, ARIZONA SP NASA, Div Micrograv Sci & Applicat, NSF, Div Mat Res, Guardian Ind Corp, Elsevier Ltd ID REFRACTIVE-INDEX CHANGES; FUSED-SILICA; WAVE-GUIDES; HEAVY-ION; SIO2; PHOTOSENSITIVITY; ABSORPTION; ORIGIN; GLASS; BORON AB Silica samples were implanted with 4 MeV Ti2+ ions at nominal doses ranging from 0.1 to 5.0 x 10(15) cm(-2). Optical absorption was measured from 3.5 to 6.5 eV and in all spectra a local maximum at 5.0 eV and a shoulder at 5.9 eV were observed. A second series of samples was implanted with 4 MeV Si2+ ions at nominal doses ranging from 0.5 to 3.0 x 10(15) cm(-2). Based on the literature we assumed that Gaussian bands at 4.8, 5.01, 5.17, 5.88, and 7.15 eV comprised the observed spectra. Using Gaussian functions as basis states, linear fits to the data were performed yielding amplitudes for each band. Between 3.5 and 5.5 eV the fits were within +/-3%. At larger energies the fits were unsatisfactory. Non-linear fits with an additional, fully adjustable Gaussian function yielded a band at 6.4 eV with full width at half maximum similar to 0.5 eV and reduced the difference between the fit and the data to <2% over the full range of the measurements. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Belmont Univ, Dept Chem Phys, Nashville, TN 37212 USA. Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. Vanderbilt Univ, Dept Mech Engn, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Magruder, RH (reprint author), Belmont Univ, Dept Chem Phys, 1900 Belmont Blvd, Nashville, TN 37212 USA. RI Hensley, Dale/A-6282-2016 OI Hensley, Dale/0000-0001-8763-7765 NR 31 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 2000 VL 274 IS 1-3 BP 282 EP 288 DI 10.1016/S0022-3093(00)00191-5 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 353WK UT WOS:000089298300039 ER PT J AU Alamgir, FM Jain, H Schwarz, RB Jin, O Williams, DB AF Alamgir, FM Jain, H Schwarz, RB Jin, O Williams, DB TI Electronic structure of Pd-based bulk metallic glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 9th International Conference on the Physics of Non-Crystalline Solids (PNS 1999) CY OCT 17-21, 1999 CL TUCSON, ARIZONA SP NASA, Div Micrograv Sci & Applicat, NSF, Div Mat Res, Guardian Ind Corp, Elsevier Ltd ID NI-P; ALLOYS AB From high-resolution X-ray photoelectron spectroscopy (XPS) of PdxNi(80-x)P20 bulk metallic glasses (BMGs) we observe bonding states in the ternary glasses that cannot be simulated by linear combinations of the valence bands of the binaries. Thus, the bonding in the ternary glasses is qualitatively different from those of the binary alloys of this composition range. Further, we observe that there are more such states in Pd40Ni40P20 than in Pd40.5Cu40.5P19, explaining the greater glass-formability of the former. Within the bulk glass formation range, 30 less than or equal to x less than or equal to 60, the valence band of the most stable glass, Pd40Ni40P20, is found to be a linear combination of those of the glasses at the extremes of this range. Comparison of XPS core level binding energies of glasses and crystals in PdxNi(80-x)P20 show that the electronic structure of glasses is closest to that of the corresponding crystals at x = 30, which agrees with a minimum in the heat of crystallization for this composition. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lehigh Univ, Dept Mat Sci & Engn, Bethlehem, PA 18015 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Jain, H (reprint author), Lehigh Univ, Dept Mat Sci & Engn, 5 E Packer Ave, Bethlehem, PA 18015 USA. OI Alamgir, Faisal/0000-0002-0894-8096 NR 19 TC 18 Z9 20 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 2000 VL 274 IS 1-3 BP 289 EP 293 DI 10.1016/S0022-3093(00)00192-7 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 353WK UT WOS:000089298300040 ER PT J AU Hess, NJ Espinosa, FJ Conradson, SD Weber, WJ AF Hess, NJ Espinosa, FJ Conradson, SD Weber, WJ TI Beta radiation effects in (137)Cs-substituted pollucite SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID ABSORPTION FINE-STRUCTURE; X-RAY-DIFFRACTION; POWDER DIFFRACTION; WASTE; IMMOBILIZATION; PLUTONIUM; ZEOLITES; NEUTRON; SPECTRA; TOOL AB The effect of high-energy beta radiation on the long-range and local structure of (137)Cs-substituted CsAlSi(2)O(6) (pollucite) was studied by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) techniques at the Cs K-edge. Analysis of the XRD pattern of pollucite with an absorbed dose of 10(18) beta decays/g using Rietveld analysis indicates a 8.5-1% volume expansion of the tetrahedral structure as measured at 50 It and a minor displacement of the Cs cation toward the face of one of the six-membered rings. Analysis of the real-space pair-distribution function obtained from Fourier transformation of the diffraction pattern indicates significant correlated movement of the (Si,Al)-O pairs and large static disorder between Cs-O pairs. Analysis of the Cs K-edge XAS revealed substantial contributions from the Cs atomic X-ray absorption. This likely results from the exceedingly long Cs-O bond distances in the pollucite structure, which diminish the fine structure of the XAS oscillations, and the destructive interference of the backscattered photoelectron from static disorder between Cs-O pairs. In addition, a significant lengthening of the Cs-Cs interatomic distance was observed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hess, NJ (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM nancy.hess@pnl.gov RI Weber, William/A-4177-2008; OI Weber, William/0000-0002-9017-7365; Hess, Nancy/0000-0002-8930-9500 NR 32 TC 20 Z9 20 U1 0 U2 10 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 SEP PY 2000 VL 281 IS 1 BP 22 EP 33 DI 10.1016/S0022-3115(00)00191-4 PG 12 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 354GR UT WOS:000089321800003 ER PT J AU Lee, EH Byun, TS Hunn, JD Hashimoto, N Farrell, K AF Lee, EH Byun, TS Hunn, JD Hashimoto, N Farrell, K TI A method to study deformation mechanisms for irradiated steels using a disk-bend test SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB There is considerable interest in understanding how dislocations interact with defect clusters produced by radiation to evaluate and remedy the radiation induced degradation of mechanical properties. In this paper, it is demonstrated that deformation mechanisms for irradiated materials can be studied with small TEM disks by employing a disk-bend method. Results showed that dominant deformation modes in ion-irradiated austenitic steel were planar glide and microtwinning. It was concluded that the disk-bend method will be a powerful tool in studying deformation microstructures of irradiated materials. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Lee, EH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI HASHIMOTO, Naoyuki/D-6366-2012 NR 19 TC 12 Z9 12 U1 0 U2 1 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 SEP PY 2000 VL 281 IS 1 BP 65 EP 70 DI 10.1016/S0022-3115(00)00130-6 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 354GR UT WOS:000089321800007 ER PT J AU Kim, IS Hunn, JD Hashimoto, N Larson, DL Maziasz, PJ Miyahara, K Lee, EH AF Kim, IS Hunn, JD Hashimoto, N Larson, DL Maziasz, PJ Miyahara, K Lee, EH TI Defect and void evolution in oxide dispersion strengthened ferritic steels under 3.2 MeV Fe+ ion irradiation with simultaneous helium injection SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID MECHANICAL-PROPERTIES; ALLOYS; METALS AB In an attempt to explore the potential of oxide dispersion strengthened (ODS) ferritic steels for fission and fusion structural materials applications, a set of ODS steels with varying oxide particle dispersion were irradiated at 650 degrees C, using 3.2 MeV Fe+ and 330 keV He+ ions simultaneously. The void formation mechanisms in these ODS steels were studied by juxtaposing the response of a 9Cr-2WVTa ferritic/martensitic steel and solution annealed AISI 316LN austenitic stainless steel under the same irradiation conditions. The results showed that void formation was suppressed progressively by introducing and retaining a higher dislocation density and finer precipitate particles. Theoretical analyses suggest that the delayed onset of void formation in ODS steels stems from the enhanced point defect recombination in the high density dislocation microstructure, lower dislocation bias due to oxide particle pinning, and a very fine dispersion of helium bubbles caused by trapping helium atoms at the particle-matrix interfaces. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Nagoya Univ, Dept Mol Design & Engn, Nagoya, Aichi, Japan. RP Lee, EH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI HASHIMOTO, Naoyuki/D-6366-2012; OI Maziasz, Philip/0000-0001-8207-334X NR 27 TC 87 Z9 97 U1 4 U2 36 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 SEP PY 2000 VL 280 IS 3 BP 264 EP 274 DI 10.1016/S0022-3115(00)00066-0 PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 343XJ UT WOS:000088727500002 ER PT J AU Park, YS Sohn, HY Butt, DP AF Park, YS Sohn, HY Butt, DP TI Thermal removal of gallium from gallia-doped ceria SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID REDUCTION AB The potential for removing gallium from Ga-doped CeO2-x by thermal means was studied for the purpose of assessing gallium removal from PuO2-x. The latter is of interest to those considering the storage or use of weapon-grade Pu, for example as a mixed oxide fuel component. Experiments were done by varying temperature, gas composition, exposure time, sample size, particle size, and gas flow rate. The kinetics of gallium removal were assessed through measurements of weight change, scanning electron microscopy, and chemical analyses. Results suggest that the gallium level can be reduced significantly by thermal treatments in Ar-6% H-2. Gallium species segregate to grain boundaries because of the low solubility of Ga2O3 in CeO2. The kinetics and microstructural observations suggest that both gaseous and solid-state diffusion of gallium species are important for the removal of gallium. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Utah, Dept Met Engn, Salt Lake City, UT 84112 USA. RP Park, YS (reprint author), US Dept Commerce, Natl Inst Stand & Technol, MS 8250, Gaithersburg, MD 20899 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 26 TC 15 Z9 15 U1 1 U2 5 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 SEP PY 2000 VL 280 IS 3 BP 285 EP 294 DI 10.1016/S0022-3115(00)00064-7 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 343XJ UT WOS:000088727500004 ER PT J AU Sagaradze, VV Lapin, SS Kirk, MA AF Sagaradze, VV Lapin, SS Kirk, MA TI Non-equilibrium intragrain concentration redistribution of the alloying elements in austenitic steels under irradiation SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID DECOMPOSITION AB Radiation-induced and thermally activated decomposition of austenitic 16Cr15Ni3Mo1Ti, 32Ni, 34Ni steels at high temperature (500-650 degrees C) were examined. High doses (up to 10-200 dpa) in 16Cr15Ni3Mo1Ti stainless steel with 1.5 MeV Kr ions and 450 keV Fe ions at 550-650 degrees C lead to the appearance of relatively large regions (up to 200-400 nm) of concentration-oscillations with 'mosaic' dark-white diffraction contrast in TEM images. The radiation-induced redistribution of alloying elements takes place thanks to inverse Kirkendall effect and, in particular, removal of Cr to cell volume from boundaries of coarse cellular structure. The competing formation of ultrafine subgrains and grains 10-50 nm in size structure in Ti-free steel (16Cr15Ni3Mo) impedes the development of large ingrain segregations. The Mossbauer investigations showed that the 32Ni and 34Ni steels with purposefully produced concentration-oscillations were fully homogenised in that high-temperature region. This fact indicated the absence of the thermal decomposition dome in the Fe-Ni equilibrium diagram. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Inst Met Phys, Ural Branch, Ekaterinburg 620219, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. RP Sagaradze, VV (reprint author), Russian Acad Sci, Inst Met Phys, Ural Branch, 18 S Kovalevskaya Str, Ekaterinburg 620219, Russia. RI Sagaradze, Victor/J-5570-2013 OI Sagaradze, Victor/0000-0002-6426-3382 NR 12 TC 4 Z9 4 U1 0 U2 3 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 SEP PY 2000 VL 280 IS 3 BP 345 EP 352 DI 10.1016/S0022-3115(00)00059-3 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 343XJ UT WOS:000088727500010 ER PT J AU Klueh, RL Cheng, ET Grossbeck, ML Bloom, EE AF Klueh, RL Cheng, ET Grossbeck, ML Bloom, EE TI Impurity effects on reduced-activation ferritic steels developed for fusion applications SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB Reduced-activation steels are being developed for fusion applications by restricting alloying elements that produce long-lived radioactive isotopes when irradiated in the fusion neutron environment. Another source of long-lived isotopes is the impurities in the steel. To examine this, three heats of reduced-activation martensitic steel were analyzed by inductively coupled plasma mass spectrometry for low-level impurities that compromise the reduced-activation characteristics: a 5-ton heat of modified F82H (F82H-Mod) for which an effort was made during production to reduce detrimental impurities, a 1-ton heat of JLF-1, and an 18-kg heat of ORNL 9Cr-2WVTa. Specimens from commercial heats of modified 9Cr-1Mo and Sandvik HT9 were also analyzed. The objective was to determine the difference in the impurity levels in the F82H-Mod and steels for which less effort was used to ensure purity. Silver, molybdenum, and niobium were found to be the tramp impurities of most importance. The F82H-Mod had the lowest levels, but in some cases the levels were not much different from the other heats. The impurity levels in the F82H-Mod produced with present technology did not achieve the low-activation limits for either shallow land burial or recycling. The results indicate the progress that has been made and what still must be done before the reduced-activation criteria can be achieved. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. TSI Res Inc, Solana Beach, CA 92075 USA. RP Klueh, RL (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,MS 6376, Oak Ridge, TN 37831 USA. NR 12 TC 38 Z9 38 U1 2 U2 10 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 SEP PY 2000 VL 280 IS 3 BP 353 EP 359 DI 10.1016/S0022-3115(00)00060-X PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 343XJ UT WOS:000088727500011 ER PT J AU Alma, MH Kelley, SS AF Alma, MH Kelley, SS TI Conversion of barks of several tree species into bakelite-like thermosetting materials by their phenolysis SO JOURNAL OF POLYMER ENGINEERING LA English DT Article DE bark; flexural strength; phenolysis; phenolated bark; sulfuric acid ID CATALYZED PHENOLATED WOOD; RESIN AB In this study, barks of several tree species, such as Calabrian pine, cedar, eucalyptus, acacia, Anatolia chestnut and Turk oak, were phenolated by using sulfuric acid as a catalyst at a temperature of 130 degreesC for 1 h. The phenolated barks obtained were cured with hexamethylenetetramine (HMTA). Then, the mechanical properties (static flexural strength) of the phenolated bark-based molding materials were evaluated. The results showed that the barks of various tree species were easily phenolated in the presence of sulfuric acid, and the phenolated bark could be molded like a commercial novolak resin. It was also found that barks with small amounts of ash were effectively phenolated in comparison to barks with large amounts of ash. On the other hand, the reaction type of the bark phenolysis could be classified as exothermic as in the production of phenol-formaldehyde resin. Eventually, it was determined that the flexural strength of the whole phenolated bark-based moldings studied, excluding phenolated acacia bark, was similar to that of the commercial novolak resin-based moldings. C1 Kahramanmaras Sutcu Imam Univ, Dept Ind Engn Forestry, TR-46060 K Maras, Turkey. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Alma, MH (reprint author), Kahramanmaras Sutcu Imam Univ, Dept Ind Engn Forestry, TR-46060 K Maras, Turkey. NR 15 TC 12 Z9 12 U1 0 U2 3 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-6447 J9 J POLYM ENG JI J. Polym. Eng. PD SEP-OCT PY 2000 VL 20 IS 5 BP 365 EP 379 PG 15 WC Polymer Science SC Polymer Science GA 381HC UT WOS:000165755600004 ER PT J AU Gong, X Dai, L Griesser, HJ Mau, AWH AF Gong, X Dai, L Griesser, HJ Mau, AWH TI Surface immobilization of poly(ethylene oxide): Structure and properties SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE poly(ethylene oxide); surface immobilization; plasma polymerization; surface characterization; protein adsorption ID PROTEIN ADSORPTION; POLYETHYLENE OXIDE; COPOLYMER CHAINS; PLASMA; ADHESION; PEO; THROMBOGENICITY; POLYURETHANE; INTERFACE; GLYCOL) AB We covalently immobilized poly(ethylene oxide) (PEO) chains onto a fluorinated ethylene propylene copolymer (FEP) surface. On the FEP surface, aldehyde groups were first deposited by plasma polymerization of acetaldehyde or acrolein. Then, amino-PEO chains were immobilized through Schiff base formation, which was followed by reduction stabilization with sodium cyanoborohydride. The PEG-grafted polymer surfaces thus prepared were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy, contact-angle measurements, and protein adsorption. The dramatic increase in the C-O intensity of the high-resolution XPS C 1s spectrum, together with an overall increase in oxygen content, indicated the successful attachment of PEO chains onto the acetaldehyde plasma surfaces. The amount of grafted PEO chains depended on the superfacial density of the plasma-generated aldehyde groups. The grafted monoamino-PEO chains formed a brushlike structure on the polymer surface, whereas the bisamino-PEO chains predominately adopted a looplike conformation. The PEO surface had a regular morphology with greater roughness than the aldehyde surface underneath. Surface hydrophilicity increased with the grafting of PEO. Also, the bisamino-PEO-grafted surface had slightly higher surface hydrophilicity than its monoamino-PEO counterpart. These PEO coatings reduced fibrinogen adsorption by 43% compared with the substrate FEP surface. (C) 2000 John Wiley & Sons, Inc. C1 CSIRO Mol Sci, Clayton, Vic 3169, Australia. RP Gong, X (reprint author), Pacific NW Natl Lab, POB 999,Battelle Blvd,K2-44, Richland, WA 99352 USA. RI Griesser, Hans/E-5628-2011 NR 43 TC 56 Z9 58 U1 2 U2 25 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 1 PY 2000 VL 38 IS 17 BP 2323 EP 2332 DI 10.1002/1099-0488(20000901)38:17<2323::AID-POLB120>3.0.CO;2-6 PG 10 WC Polymer Science SC Polymer Science GA 344QX UT WOS:000088771300012 ER PT J AU Gover, R Kanno, R Mitchell, B Hirano, A Kawamoto, Y AF Gover, R Kanno, R Mitchell, B Hirano, A Kawamoto, Y TI The effects of sintering time on the structure and electrochemical properties of Li(Ni0.8Co0.2)O-2 SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT International Symposium on Rechargeable Lithium Batteries CY NOV 14-16, 1999 CL KYOTO, JAPAN DE sintering time; electrochemical charge/discharge measurements; structure analysis ID NEUTRON-DIFFRACTION; LITHIUM; ELECTRODE; OXIDE AB We present the findings of a new study on the effects of sintering time on the structure and electrochemical properties of layered Li(Ni0.8Co0.2)O-2. Fur this study, we have examined samples prepared with sintering times of 3, 24, 48 and 96 h. The structure was initially examined by powder X-ray diffraction and then more precisely by time of flight powder neutron diffraction, with structural analysis by the Rietveld method being performed. The structural analysis indicated differences in the Li 3a and Ni/Co 3b site occupancies, which appear to be related to the sintering times. Electrochemical charge/discharge measurements indicated that the initial discharge capacities for the samples prepared at 3, 24, and 48 h were basically invariant. However, a sizeable increase was noted for the sample prepared with a sintering time of 96 h. Also, an increase in the obtained discharge capacity from the first to second cycles was found for the samples prepared with 3-48 h sintering times. The largest increase was noted for the sample prepared for 48 h. No increase was seen for the sample sintered for 96 h. However, for all, samples examined in this work, the capacities on first discharge were in excess of 180 mA h/g. (C) 2000 Elsevier Science S.A, All rights reserved. C1 Kobe Univ, Fac Sci, Dept Chem, Kobe, Hyogo 6578501, Japan. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Kobe Univ, Fac Sci, Dept Chem, 1-1 Rokko Dai, Kobe, Hyogo 6578501, Japan. EM kanno@kobe-u.ac.jp NR 14 TC 34 Z9 35 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 EI 1873-2755 J9 J POWER SOURCES JI J. Power Sources PD SEP PY 2000 VL 90 IS 1 BP 82 EP 88 DI 10.1016/S0378-7753(00)00452-3 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 337CF UT WOS:000088339300015 ER PT J AU Dewberry, RA Leyba, JD Boyce, WT AF Dewberry, RA Leyba, JD Boyce, WT TI Observation and measurement of Se-79 in Savannah River Site high level waste tank fission product waste SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB We report the first observation of confirmed Se-79 activity in Savannah River Site high level fission product waste. Se-79 was measured after a seven step chemical treatment to remove interfering activity from Cs-137, Sr-90, and plutonium at levels 10(5) times higher than the observed Se-79 content and to remove Tc-99 at levels 300 times higher than observed Se-79. Se-79 was measured by liquid scintillation beta-decay counting after specific tests to eliminate uncertainties from possible contributions from Tc-99, Pm-147, Sm-151, Zr-93, or Pu-241 whose beta-decay spectra could appear similar to that of Se-79, and whose content would be expected at levels near or greater than 79Se. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29802 USA. RP Dewberry, RA (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29802 USA. NR 11 TC 9 Z9 10 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD SEP PY 2000 VL 245 IS 3 BP 491 EP 500 DI 10.1023/A:1006736621914 PG 10 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 360NE UT WOS:000089673500006 ER PT J AU Salve, R Tokunaga, TK AF Salve, R Tokunaga, TK TI Flow processes in a rangeland catchment in California SO JOURNAL OF RANGE MANAGEMENT LA English DT Article DE California rangelands; subsurface flow; water budget ID GROUNDWATER RECHARGE; WATER-BALANCE; CHLORIDE; SOIL; SITE AB Emerging hydrology-related issues in California grasslands have directed attention towards the need to understand subsurface water flow within a complex, dynamic system. Tensiometers and neutron probes evaluated the subsurface hydrology of a rangeland catchment. Hydrological processes within the catchment varied both in space and time. Spatial variability was evident along the vertical profile and between the catchment slopes. Temporal variability in processes coincided with the seasons (i.e., wet winter, dry summer, and spring). From a water-balance equation developed for the catchment, we determined that there was significant variability both spatial and temporal in the amount of soil moisture lost to evapotranspiration and deep seepage. During the 16 month monitoring period there was a total of 50 cm of rainfall that fell in the catchment of which 9-55 cm was lost to evaporation and 37-79 cm to deep seepage. A simple deduction of the losses (evaporation and deep seepage) from the input (rainfall) shows that all monitored locations had a substantial decrease in the amount of water that was stored in the soil profile. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA. RP Salve, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Tokunaga, Tetsu/H-2790-2014 OI Tokunaga, Tetsu/0000-0003-0861-6128 NR 24 TC 5 Z9 5 U1 0 U2 1 PU SOC RANGE MANAGEMENT PI LAKEWOOD PA 445 UNION BLVD, STE 230, LAKEWOOD, CO 80228-1259 USA SN 0022-409X J9 J RANGE MANAGE JI J. Range Manage. PD SEP PY 2000 VL 53 IS 5 BP 489 EP 498 DI 10.2307/4003649 PG 10 WC Agriculture, Dairy & Animal Science; Ecology SC Agriculture; Environmental Sciences & Ecology GA 388AY UT WOS:000166156300005 ER PT J AU Zhang, DZ Rauenzahn, RM AF Zhang, DZ Rauenzahn, RM TI Stress relaxation in dense and slow granular flows SO JOURNAL OF RHEOLOGY LA English DT Article ID AVERAGED EQUATIONS; PARTICLES; SPHERES; SHEAR AB In a dense granular system, particles interact in networks containing many particles and interaction times are long compared with the particle binary collision time. In these systems, the streaming part of the granular stress is negligible. We only consider the collisional stress in this paper. The average behavior of particle contacts is studied. By following the statistical method developed recently by the authors [Zhang and Rauenzahn, J. Rheol. 41, 1275 (1997)], we derive an evolution equation for the collisional stress. This equation provides guidance to collateral numerical simulations, which show that the probability distribution of particle contact times is exponential for long contact times. This can be explained by network interactions in a dense granular system. In general, the relaxation of the collisional stress is a combined effect of the decay of the contact time probability and the relaxation of collisional forces among particles. In the numerical simulations, the normal force between a pair of particles is modeled as parallel connect of a spring and a dashpot. In this case, the relaxation of the force magnitude conditionally averaged given a specific contact time is negligible, and the major contribution to the stress relaxation is from the exponential decay of the contact time probability. We also note that the probability decay rate is proportional to the imposed strain rate. Consequently, in a simple shear flow with a constant particle volume fraction, as the shear rate approaches zero, the shear stress approaches a finite value. This value is the yield stress for that particle volume fraction. Hence, the evolution equation of the collisional stress predicts viscoplasticity of dense granular systems. (C) 2000 The Society of Rheology. [S0148-6055(00)00105-X]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, Los Alamos, NM 87545 USA. RP Zhang, DZ (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, T-3,B216, Los Alamos, NM 87545 USA. NR 22 TC 30 Z9 32 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0148-6055 J9 J RHEOL JI J. Rheol. PD SEP-OCT PY 2000 VL 44 IS 5 BP 1019 EP 1041 DI 10.1122/1.1287287 PG 23 WC Mechanics SC Mechanics GA 352NZ UT WOS:000089225900002 ER PT J AU Ozawa, TC Pantoja, R Axtell, EA Kauzlarich, SM Greedan, JE Bieringer, M Richardson, JW AF Ozawa, TC Pantoja, R Axtell, EA Kauzlarich, SM Greedan, JE Bieringer, M Richardson, JW TI Powder neutron diffraction studies of Na2Ti2Sb2O and its structure-property relationships SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE pnictide-oxide; neutron diffraction; CDW; SDW; layered oxide ID PNICTIDE OXIDE COMPOUNDS; CRYSTAL-STRUCTURE; PHASE-TRANSITION; TUNGSTEN BRONZES; RARE EXAMPLE; SPIN; LAYER; BA; OXYSULFIDES; NATIO2 AB The structure of Na2Ti2Sb2O has been investigated by temperature-dependent powder neutron diffraction. Na2Ti2Sb2O crystallizes in I4/mmm symmetry. The structure of this phase can be viewed as an anti-K2NiF4 type where Ti3+ ion is located between two oxygen atoms forming a square-planar lattice. Powder neutron diffraction studies of Na2Ti2Sb2O indicate that this compound has a structural distortion in the [Ti2Sb2O](2-) layer at T approximate to 1120 K, This transition corresponds well to the previously reported anomalous transition temperature of the magnetic susceptibility and electronic resistivity, Several models to explain the data are presented and discussed, (C) 2000 Academic Press. C1 Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. McMaster Univ, Inst Mat Res, Hamilton, ON L8S 4M1, Canada. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Kauzlarich, SM (reprint author), Univ Calif Davis, Dept Chem, 1 Shields Ave, Davis, CA 95616 USA. RI Kauzlarich, Susan/H-1439-2011; Ozawa, Tadashi C./B-2535-2012 OI Ozawa, Tadashi C./0000-0003-0118-115X NR 41 TC 39 Z9 40 U1 1 U2 28 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD SEP PY 2000 VL 153 IS 2 BP 275 EP 281 DI 10.1006/jssc.2000.8758 PG 7 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 350CH UT WOS:000089082800011 ER PT J AU Kim, SJ Hu, SQ Uher, C Hogan, T Huang, BQ Corbett, JD Kanatzidis, MG AF Kim, SJ Hu, SQ Uher, C Hogan, T Huang, BQ Corbett, JD Kanatzidis, MG TI Structure and thermoelectric properties of Ba6Ge25-x, Ba6Ge23Sn2, and Ba6Ge22In3: Zintl phases with a chiral clathrate structure SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE chiral clathrate; thermoelectric; zintl phase; phonon gas; electron crystal ID LATTICE THERMAL-CONDUCTIVITY; SYSTEMS; GERMANIUM; GE AB A single phase of Ba6Ge25-x (x similar to 1) was obtained from a direct element combination reaction in a sealed graphite tube at 830 degrees C, Its structure was determined by single-crystal X-ray diffraction methods, Ba6Ge25-x adopts the chiral cubic space group P4(1)32 (No, 213) with dimensions of a = 14.5483(2) Angstrom and Z = 4, The structure consists of helical chains of Ba atom-centered pentagonal dodecahedra, Ba@Ge-20, and zeolite-like cages formed by those chains. There are vacancies distributed over the Ge sites giving a composition of Ba6Ge24, in which charge balance according to the Zintl formalism is retained, The compound therefore satisfies the classical Zintl concept, Polycrystalline ingots of Ba6Ge25-x showed an electrical conductivity of 2000 S/cm and a Seebeck coefficient of -18 mu V/K at room temperature. An anomalous broad transition in the electrical conductivity and Seebeck coefficient was observed at similar to 100 K, Ba6Ge23.32Sn1.68 and Ba6Ge21.93In3.07 as ternary derivatives of Ba6Ge25-x were also synthesized and their structural and physical properties compared with those of Ba6Ge25-x. (C) 2000 Academic Press. C1 Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Michigan State Univ, Dept Elect & Comp Engn, E Lansing, MI 48824 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. Ewha Womans Univ, Dept Chem, Seoul 120750, South Korea. RP Kanatzidis, MG (reprint author), Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA. NR 31 TC 78 Z9 79 U1 4 U2 24 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 SEP PY 2000 VL 153 IS 2 BP 321 EP 329 DI 10.1006/jssc.2000.8777 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 350CH UT WOS:000089082800018 ER PT J AU Wang, J Brinza, DE Young, DT Nordholt, JE Polk, JE Henry, MD Goldstein, R Hanley, JJ Lawrence, DJ Shappirio, M AF Wang, J Brinza, DE Young, DT Nordholt, JE Polk, JE Henry, MD Goldstein, R Hanley, JJ Lawrence, DJ Shappirio, M TI Deep Space One investigations of ion propulsion plasma environment SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID CONTAMINATION AB Deep Space One (DSI) is the first interplanetary spacecraft operated on solar electric propulsion. One of the primary investigations of DSI is to characterize ion propulsion-induced plasma interactions and their effects on spacecraft and solar wind measurements based on two plasma diagnostic packages. The first in situ measurements of an ion propulsion-induced plasma environment obtained from an interplanetary spacecraft are reported. Analysis of the measurements reveals interesting correlations between the induced charge-exchange plasma environment and thruster operating conditions. Sensors near the thruster exit measured charge-exchange ions with a number density of similar to 10(6) cm(-3) and a current density of similar to 10(-7) A/cm(-2) under typical thruster operating conditions, a result in good agreement with preflight predictions based on computer particle simulations. Observations on the opposite side from the thruster suggest that the dominant factor for charge-exchange ion backflow is the potential distribution surrounding the spacecraft rather than the charge-exchange ion production rate. C1 CALTECH, Jet Prop Lab, Measurement Test & Environm Support Sect, Pasadena, CA 91109 USA. SW Res Inst, Dept Space Sci, San Antonio, TX 78228 USA. Univ Calif Los Alamos Natl Lab, Space & Atmospher Sci Grp, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Avion Syst Engn Sect, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, Adv Propuls Technol Grp, Pasadena, CA 91109 USA. RP Wang, J (reprint author), CALTECH, Jet Prop Lab, Measurement Test & Environm Support Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Lawrence, David/E-7463-2015 OI Lawrence, David/0000-0002-7696-6667 NR 16 TC 19 Z9 21 U1 0 U2 6 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2000 VL 37 IS 5 BP 545 EP 555 DI 10.2514/2.3608 PG 11 WC Engineering, Aerospace SC Engineering GA 364LN UT WOS:000089894000001 ER PT J AU Jansons, KM Lythe, GD AF Jansons, KM Lythe, GD TI Efficient numerical solution of stochastic differential equations using exponential timestepping SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE stochastic calculus; stochastic algorithm; Wiener process; diffusion with boundaries AB We present an exact timestepping method for Brownian motion that does not require Gaussian random variables to be generated. Time is incremented in steps that are exponentially-distributed random variables; boundaries can be explicitly accounted for at each timestep. The method is illustrated by numerical solution of a system of diffiising particles. C1 UCL, Dept Math, London WC1E 6BT, England. Los Alamos Natl Lab, T7, Los Alamos, NM 87544 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87544 USA. RP Jansons, KM (reprint author), UCL, Dept Math, Gower St, London WC1E 6BT, England. EM Kalvis@Bigfoot.Com; GrantLythe@Bigfoot.Com OI Lythe, Grant/0000-0001-7966-5571 NR 17 TC 16 Z9 16 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD SEP PY 2000 VL 100 IS 5-6 BP 1097 EP 1109 DI 10.1023/A:1018711024740 PG 13 WC Physics, Mathematical SC Physics GA 378NK UT WOS:000165590300015 ER PT J AU Bortel, G Alp, EE Sturhahn, W Toellner, TS AF Bortel, G Alp, EE Sturhahn, W Toellner, TS TI Wavelength-dispersive double flat-crystal analyzer for inelastic X-ray scattering SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE X-ray optics; crystal analyzers; resonant/anomalous inelastic X-ray scattering; absorption edges; electronic and vibrational excitations; parallel data collection ID MEV ENERGY RESOLUTION; BACKSCATTERING AB A double flat-crystal analyzer for inelastic X-ray scattering is described. The general correlation between the energy and direction of the X-rays transmitted by the analyzer allows one to collect data for a range of energy transfers simultaneously. Such an analyzer with 120 meV resolution was built to operate at the copper K edge. Experimental results show that this X-ray optic can be an alternative to a conventional spherical-focusing backscattering analyzer in resonant inelastic X-ray scattering experiments or when flexible energy resolution or high momentum resolution is required. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Bortel, G (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD SEP PY 2000 VL 7 BP 333 EP 339 DI 10.1107/S090904950000950X PN 5 PG 7 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 347AR UT WOS:000088904500008 PM 16609217 ER PT J AU Suortti, P Fiedler, S Bravin, A Brochard, T Mattenet, M Renier, M Spanne, P Thomlinson, W Charvet, AM Elleaume, H Schulze-Briese, C Thompson, AC AF Suortti, P Fiedler, S Bravin, A Brochard, T Mattenet, M Renier, M Spanne, P Thomlinson, W Charvet, AM Elleaume, H Schulze-Briese, C Thompson, AC TI Fixed-exit monochromator for computed tomography with synchrotron radiation at energies 18-90 keV SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE X-ray optics; monochromators; computed tomography; X-ray imaging ID BENT LAUE MONOCHROMATOR; CRYSTAL MONOCHROMATORS; CORONARY ANGIOGRAPHY; BEAM AB A fixed-exit monochromator has been constructed for computed tomography (CT) studies at the Medical Beamline of the European Synchrotron Radiation Facility. A non-dispersive pair of bent Laue-type crystals is used, and the first crystal is water-cooled. The monochromator operates at energies from 18 to 90 keV, and the maximum width of the beam is 150 mm. The performance of the monochromator is studied with respect to the beam intensity and energy distributions, and a close agreement is found between the calculated and experimental results. The intensity is between 10(9) and 10(10) photons s(-1) mm(-2) under typical operating conditions. The harmonic content of a 25 keV beam is about 30% at the minimum wiggler gap of 25 mm (field 1.57 T) and decreases by an order of magnitude when the gap is increased to 60 mm (field 0.62 T). The experimental set-up for CT studies includes dose monitors, goniometers and translation stages for positioning and scanning the object, and a 432-element linear-array Ge detector. Examples from phantom studies and in vivo animal experiments are shown to illustrate the spatial resolution and contrast of the reconstructed images. C1 European Synchrotron Radiat Facil, F-38043 Grenoble, France. CHU Grenoble, Unite IRM, F-38043 Grenoble, France. Swiss Light Source, CH-5232 Villigen, Switzerland. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Suortti, P (reprint author), Univ Helsinki, Dept Phys, POB 9, FIN-00014 Helsinki, Finland. RI bravin, alberto/B-4911-2008; Elleaume, Helene/F-2554-2013; Bravin, Alberto/R-8633-2016 OI Bravin, Alberto/0000-0001-6868-2755 NR 18 TC 37 Z9 41 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD SEP PY 2000 VL 7 BP 340 EP 347 DI 10.1107/S0909049500008384 PN 5 PG 8 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 347AR UT WOS:000088904500009 PM 16609218 ER PT J AU Rao, AJ Pagilla, KR Wagh, AS AF Rao, AJ Pagilla, KR Wagh, AS TI Stabilization and solidification of metal-laden wastes by compaction and magnesium phosphate-based binder SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article AB Bench-scale and full-scale investigations of waste stabilization and volume reduction were conducted using spiked soil and ash wastes containing heavy metals such as Cd, Cr, Pb, Ni, and Hg. The waste streams were stabilized and solidified using chemically bonded phosphate ceramic (CBPC) binder, and then compacted by either uniaxial or harmonic press for volume reduction. The physical properties of the final waste forms were determined by measuring volume reduction, density, porosity, and compressive strength. The leachability of heavy metals in the final waste forms was determined by a toxicity characteristic leaching procedure (TCLP) test and a 90-day immersion test (ANS 16.1). The structural composition and nature of waste forms were determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. CBPC binder and compaction can achieve 80-wt % waste loading and 39-47% reduction in waste volume. Compressive strength of final waste forms ranged from 1500 to 2000 psi. TCLP testing of waste forms showed that all heavy metals except Hg passed the TCLP limits using the phosphate-based binder. When Na2S was added to the binder, the waste forms also passed TCLP limits for Hg. Long-term leachability resistance of the final waste forms was achieved for all metals in both soil and ash wastes, and the leachability index was similar to 14. XRD patterns of waste forms indicated vermiculite in the ash waste was chemically incorporated into the CBPC matrix. SEM showed that waste forms are layered when compacted by uniaxial press and are homogeneous when compacted by harmonic press. C1 IIT, Dept Chem & Environm Engn, Chicago, IL 60613 USA. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Rao, AJ (reprint author), IIT, Dept Chem & Environm Engn, Chicago, IL 60613 USA. RI Pagilla, Krishna/K-9254-2013; OI Wagh, Arun/0000-0002-8678-7574 NR 17 TC 9 Z9 10 U1 0 U2 8 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD SEP PY 2000 VL 50 IS 9 BP 1623 EP 1631 PG 9 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 358LD UT WOS:000089558800004 PM 11055158 ER PT J AU Lai, ACK Thatcher, TL Nazaroff, WW AF Lai, ACK Thatcher, TL Nazaroff, WW TI Inhalation transfer factors for air pollution health risk assessment SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID EXPOSURE; MODEL; DISPERSION; RATES AB To facilitate routine health risk assessments, we develop the concept of an inhalation transfer factor (ITF). The ITF is defined as the pollutant mass inhaled by an exposed individual per unit pollutant mass emitted from an air pollution source. A cumulative population inhalation transfer factor (PITF) is also defined to describe the total fraction of an emitted pollutant inhaled by all members of the exposed population. In this paper, ITFs and PITFs are calculated for outdoor releases from area, point, and line sources, indoor releases in single zone and multizone indoor environments, and releases within motor vehicles. Typical PITFs for an urban area from emissions outdoors are similar to 10(-6)-10(-3). PITFs associated with emissions in buildings or in moving vehicles are typically much higher, similar to 10(-3)-10(-1). C1 Ernest Orlando Lawrence Berkeley Natl Lab, Indoor Environm Dept, Environm Energy Technol Div, Berkeley, CA USA. Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. RP Lai, ACK (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, Indoor Environm Dept, Environm Energy Technol Div, Berkeley, CA USA. RI Lai, Alvin/G-8409-2011; Nazaroff, William/C-4106-2008 OI Lai, Alvin/0000-0002-6202-1988; Nazaroff, William/0000-0001-5645-3357 NR 28 TC 66 Z9 68 U1 0 U2 8 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD SEP PY 2000 VL 50 IS 9 BP 1688 EP 1699 PG 12 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 358LD UT WOS:000089558800012 PM 11055166 ER PT J AU Winter, AN Corff, BA Reimanis, IE Rabin, BH AF Winter, AN Corff, BA Reimanis, IE Rabin, BH TI Fabrication of graded nickel-alumina composites with a thermal-behavior-matching process SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID RESIDUAL-STRESSES; MECHANICAL-PROPERTIES; FRACTURE; MICROSTRUCTURE; INTERFACES; TOUGHNESS; COATINGS; STRAINS; FEM AB Composites of nickel and Al2O3 with compositionally graded microstructures were fabricated from powders through an empirically determined thermal-behavior-matching process that was designed to minimize processing-induced stresses. Compositions ranged from pure Al2O3 to pure nickel. Specimen geometries included round disks 25 mm in diameter and 5-25 mm thick, as well as rectangular bars 25 mm x 25 mm in cross section and 75 mm long. Several different gradients were produced, including samples with single interlayers, Compacts were formed by cold uniaxial pressing in a die, followed by consolidation through sintering at 1 atm or hot isostatic pressing. Several different particle sizes of nickel and Al2O3 comprised the composite interlayers. The compaction behavior, sintering start temperature, sintering rate, and total linear shrinkage of each composition were evaluated, Careful data analysis, coupled with sintering theory, led to a layer configuration with matched green density and sintering behavior. Thermomechanically matched layers allowed large, crack-free, graded composites to be produced. C1 Colorado Sch Mines, Dept Met & Mat Engn, Golden, CO 80401 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Reimanis, IE (reprint author), Colorado Sch Mines, Dept Met & Mat Engn, Golden, CO 80401 USA. NR 39 TC 21 Z9 22 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 SEP PY 2000 VL 83 IS 9 BP 2147 EP 2154 PG 8 WC Materials Science, Ceramics SC Materials Science GA 352EL UT WOS:000089201500002 ER PT J AU Sharif, AA Chu, F Misra, A Mitchell, TE Petrovic, JJ AF Sharif, AA Chu, F Misra, A Mitchell, TE Petrovic, JJ TI Elastic constants of erbia single crystals SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MODULI AB The elastic properties of single-crystalline erbia (Er2O3) at room temperature have been investigated using resonant ultrasound spectroscopy. The three independent stiffness constants of anisotropic Er2O3 cubic type-C crystals have been measured. The values of the stiffness constants were c(11) 256.4 GPa, c(12) = 1 16.8 Cpa, and c(44) = 75.2 GPa, From the stiffness constants, the estimated values for dense polycrystalline erbia for Young's modulus, the shear modulus, the hulk modulus, and Poisson's ratio at room temperature were 179 GPa, 67 GPa, 183.3 Cpa, and 0337, respectively. The value of Young's modulus is a minimum along [001] and a maximum along [111], The value of the shear modulus is independent of the direction in the (001) and (111) planes, whereas it decreases in (1(1) over bar 0) from 75 GPa along [001] to 55 GPa along [110]. C1 Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87544 USA. RP Sharif, AA (reprint author), Univ Michigan, Dept Engn Sci, Flint, MI 48502 USA. RI Misra, Amit/H-1087-2012 NR 30 TC 11 Z9 11 U1 0 U2 7 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 2000 VL 83 IS 9 BP 2246 EP 2250 PG 5 WC Materials Science, Ceramics SC Materials Science GA 352EL UT WOS:000089201500016 ER PT J AU Debre, O Budde, WL Song, XB AF Debre, O Budde, WL Song, XB TI Negative ion electrospray of bromo- and chloroacetic acids and an evaluation of exact mass measurements with a bench-top time-of-flight mass spectrometer SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID IONIZATION AB The negative ion electrospray mass spectra of six bromo- and chloroacetic acids were measured using two different electrospray interfaces and single quadrupole and bench-top time-of-flight mass spectrometers. With each acid at 50 mu g/mL in aqueous methanol at pH 10, the anions observed included deprotonated molecules, adducts, and fragment ions. With each acid at 100 ng/mL in aqueous acetonitrile at pH 10, mainly deprotonated molecules are observed. The exact m/z measuring capability of the time-of-flight mass spectrometer was evaluated to assess the potential for the determination of the individual acids in mixtures without an on-line separation Mean measurement errors were nearly always less than +/- 9 ppm and the majority were less than +/- 5 ppm. Potential interferences by substances having similar exact: masses and the ability to form anions in aqueous solutions were evaluated. The estimated detection limits of the five regulated haloacetic acids in drinking water, without a sample preconcentration step, are in the range of 24-86 ng/mL, which is within about a factor of 10 of the levels required for routine monitoring of the acids. Actual drinking water samples were not. analyzed pending the development of slightly more sensitive techniques and quantitative analytical procedures. (C) 2000 American Society for Mass Spectrometry. C1 US EPA, Off Res & Dev, Cincinnati, OH 45268 USA. Natl Res Council, Cincinnati, OH USA. Oak Ridge Inst Sci & Educ Postdoctoral Res, Cincinnati, OH USA. RP Budde, WL (reprint author), US EPA, Off Res & Dev, 26 W Martin L King Dr, Cincinnati, OH 45268 USA. NR 13 TC 16 Z9 16 U1 0 U2 5 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 SEP PY 2000 VL 11 IS 9 BP 809 EP 821 DI 10.1016/S1044-0305(00)00147-1 PG 13 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 349JB UT WOS:000089041000008 ER PT J AU Hong, JS Selman, JR AF Hong, JS Selman, JR TI Relationship between calorimetric and structural characteristics of lithium-ion cells - I. Thermal analysis and phase diagram SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID INTERCALATION; INSERTION; MODEL; THERMODYNAMICS; SPECTROSCOPY; HYSTERESIS; BATTERIES; GRAPHITE; LIXCOO2; LIXTIS2 AB A phase diagram for LixCoO2 was determined by potentiometric and calorimetric measurements as a function of lithium concentration (x) in the host electrode. These measurements show clear evidence for a reversible phase transition between hexagonal and monoclinic structures near x = 0.5 in LixCoO2 during electrochemical-calorimetric cycling at various cell temperatures. The phase transition and the range over which it occurs were found to be temperature dependent. It was well correlated with observations that, during discharge of lithium-ion cells having LixCoO2 as positive electrode material, the overall exothermic heat effect contains a transient contribution between exothermic and endothermic heat generation near x = 0.5. (C) 2000 The Electrochemical Society. S0013-4651(00)02-009-7. All rights reserved. C1 IIT, Dept Environm Chem & Engn, Ctr Electrochem Sci & Engn, Chicago, IL 60616 USA. RP Hong, JS (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 28 TC 11 Z9 12 U1 0 U2 8 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 2000 VL 147 IS 9 BP 3183 EP 3189 DI 10.1149/1.1393881 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 353FL UT WOS:000089264100004 ER PT J AU Hong, JS Selman, JR AF Hong, JS Selman, JR TI Relationship between calorimetric and structural characteristics of lithium-ion cells - II. Determination of Li transport properties SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID INTERCALATION; LIXCOO2; ELECTRODES; DIFFUSION; LICOO2 AB The effective chemical diffusion coefficient of Li (DLi+) and related kinetic properties for lithium intercalation/deintercalation in LixCoO2 were determined by the galvanostatic intermittent titration technique (GITT). DLi+ values reached a peak at ca. x = 0.5 in LixCoO2, and this maximum correlates with phase transitions in the lithium host electrode which were indicated by the enhancement factor (W) and area-specific impedance () variations. The phase dependence of the DLi+ values at about x = 0.5 was investigated, and a decrease of DLi+ value with increasing temperature was found. The DLi+ behavior during cycling confirms that the phase transition is reversible. (C) 2000 The Electrochemical Society. S0013-4651 (00)02-008-5. All rights reserved. C1 IIT, Dept Environm Chem & Engn, Ctr Electrochem Sci & Engn, Chicago, IL 60616 USA. RP Hong, JS (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 22 TC 25 Z9 26 U1 0 U2 15 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 2000 VL 147 IS 9 BP 3190 EP 3194 DI 10.1149/1.1393882 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 353FL UT WOS:000089264100005 ER PT J AU Stevenson, JW Hasinska, K Canfield, NL Armstrong, TR AF Stevenson, JW Hasinska, K Canfield, NL Armstrong, TR TI Influence of cobalt and iron additions on the electrical and thermal properties of (La,Sr)(Ga,Mg)O3-delta SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID DOPED LANTHANUM GALLATE; PEROVSKITE-TYPE OXIDE; FUEL-CELLS; CATHODE MATERIALS; LAGAO3-BASED ELECTROLYTE; IONIC-CONDUCTIVITY; CHROMITE; TRANSPORT AB (La,Sr)(Ga,Mg)O3-delta (LSGM) perovskite compositions doped with Co or Fe were prepared by a combustion synthesis technique. Small doping levels of Co or Fe (less than or equal to 10 mol% on the B-site) resulted in increased electrical conductivity at low temperatures (due to the introduction of electronic charge carriers into the lattice), but at high temperatures the electrical conductivity was dominated by ionic conduction and was similar in magnitude to that of the base LSGM composition. Higher additions of Co or Fe resulted in much higher electrical conductivity in which the electronic component was dominant. A reversible weight loss at elevated temperatures was observed in all of the compositions as the lattice oxygen stoichiometry decreased with increasing temperature. This loss of lattice oxygen correlated with a reduction in the rate of increase (or even a net decrease) in electrical conductivity with increasing temperature. This behavior was attributed to the elimination of electronic charge carriers (and a reduction in valence of some of the Co or Fe cations in the material) as lattice oxygen vacancies were formed. The thermal expansion of the materials increased substantially with increasing Co content, while only slight increases in thermal expansion were observed with increasing Fe content. (C) 2000 The Electrochemical Society. S0013-4651(00)01-088-0. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Stevenson, JW (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI pelosato, renato/E-9950-2010 NR 27 TC 52 Z9 52 U1 0 U2 6 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 2000 VL 147 IS 9 BP 3213 EP 3218 DI 10.1149/1.1393885 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 353FL UT WOS:000089264100008 ER PT J AU He, XM Walter, KC Nastasi, M Lee, ST Fung, MK AF He, XM Walter, KC Nastasi, M Lee, ST Fung, MK TI Investigation of Si-doped diamond-like carbon films synthesized by plasma immersion ion processing SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID AMORPHOUS HYDROGENATED CARBON; CHEMICAL VAPOR-DEPOSITION; OPTICAL-PROPERTIES; COATINGS; SPECTRA AB Silicon (Si)-doped diamond-like carbon (DLC) was prepared on Si(100) and polymethyl methacrylate (PMMA) substrates using a C2H2-SiH4-Ar plasma immersion ion processing (PIIP) method. The chemical composition of the films was varied by adjusting the reactive gas-flow ratio of SiH4 to C2H2 during PIIP depositions. The influence of the Si dopant on the bonding structure, stress, and properties of the DLC films was investigated by using ion beam analysis techniques, Raman shift, ultraviolet/visible spectroscopy, and by analyzing the measured properties. The incorporation of Si up to 17.3 at. % produced a reduction in film stress and increased the density and optical band gap. The Si-doped DLC films also exhibited increased sp(3) bonding and higher hardness (25-28 GPa). Further increase in Si dopant, to above 22 at. %, caused a transformation from DLC to amorphous silicon carbide (a-SiC) that showed high hydrogen capacity, low hardness, and low stress. Pin-on-disk tribological tests df Si-doped DLC on PMMA showed greatly improved wear and friction properties related to the uncoated PMMA. (C) 2000 American Vacuum Society. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. City Univ Hong Kong, Dept Phys & Mat Sci, Hong Kong, Hong Kong, Peoples R China. RP He, XM (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 28 TC 37 Z9 38 U1 4 U2 13 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2000 VL 18 IS 5 BP 2143 EP 2148 DI 10.1116/1.1286141 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 356GD UT WOS:000089434800016 ER PT J AU Hayoz, J Pillo, T Bovet, M Zuttel, A Guthrie, S Pastore, G Schlapbach, L Aebi, P AF Hayoz, J Pillo, T Bovet, M Zuttel, A Guthrie, S Pastore, G Schlapbach, L Aebi, P TI Preparation and characterization of clean, single-crystalline YHx films (0 <= x <= 2.9) on W(110) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID RAY PHOTOELECTRON DIFFRACTION; SWITCHABLE OPTICAL-PROPERTIES; ELECTRONIC-STRUCTURE; HYDRIDE FILMS; HYDROGEN; SURFACE; SPECTROSCOPY; YTTRIUM; TRANSITION; MEMBRANE AB Yttrium can be loaded with hydrogen up to high concentrations causing dramatic structural and electronic changes of the host lattice. We report on the preparation of clean, single-crystalline YHx films (0 less than or equal to x less than or equal to 2.9). The films have been characterized in situ combining angle-resolved photoelectron spectroscopy (ARPES) and low energy electron diffraction. Direct Y dihydride growth, i.e., Y evaporation under a H-2 partial pressures of approximate to 5 x 10(-6) mbar at 500 K on W(110), is the most convenient starting point for the preparation of clean single-crystalline Y hydride films covering H concentrations from the "clean metal" (x approximate to 0) up to the lower boundary of the pure trihydride phase (x approximate to 2.9). Upon annealing Y dihydride films the desired H concentration can be adjusted within the alpha-phase or the (alpha+beta) two-phase regime. On the other hand, the extension of our photoelectron spectrometer with an homemade ultrahigh vacuum (UHV) compatible hydrogenation system allows to induce the transition from Y dihydride to Y trihydride within a few minutes. The hydrogenation system combines a high-pressure reaction cell with hydrogen permeation through a Pd-24%Ag tube. The overall design is such that the sample never gets in contact with non-UHV compartments. For direct Y dihydride growth on W(110) two equally populated face-centered-cubic(lll) domains rotated by 180 degrees with respect to each other are observed. In the alpha- and gamma-phase the Y atoms form a hexagonal-close-packed(0001) oriented lattice. Furthermore, the previously established model for in situ I-I concentration estimation in Y [J. Hayoz et al., Phys: Rev. B 58, R4270 (1998)] is extended successfully from the alpha to beta to the beta to gamma-phase transition. Ultraviolet photoemission spectroscopy data unequivocally reveal the opening of a gap extending as far as 1 eV below E-F for normal electron emission upon the phase-transformation from Y dihydride to Y trihydride. It also appears that the H absorption rate strongly depends on the H-2 purity. Our experimental results demonstrate the capability of this setup for in situ preparation and investigations on the geometrical and electronic structure of Y hydride films and, more generally, rare-earth hydride films using ARPES. (C) 2000 American Vacuum Society. [S0734-2101(00)01805-4]. C1 Univ Fribourg, Inst Phys, Perolles, CH-1700 Fribourg, Switzerland. Sandia Natl Labs, Surface Chem Dept, Livermore, CA 94551 USA. SAES Getters SPA, I-20020 Lainate, MI, Italy. RP Hayoz, J (reprint author), Penn State Univ, Dept Phys, University Pk, PA 16802 USA. NR 50 TC 17 Z9 17 U1 3 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2000 VL 18 IS 5 BP 2417 EP 2431 DI 10.1116/1.1286073 PG 15 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 356GD UT WOS:000089434800057 ER PT J AU Misra, A Nastasi, M AF Misra, A Nastasi, M TI The role of oxygen in the intrinsic tensile residual stress evolution in sputter-deposited thin metal films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID MULTILAYERS; IMPURITIES; SILVER; COPPER AB The intrinsic tensile stress and oxygen content in thin Cr films sputter deposited at high argon pressure are investigated as a function of negative substrate bias. With increasing bias from 0 to -100 V, the tensile stress increases to a maximum while the oxygen content decreases. At bias higher than - 100 V, the tensile stress decreases but no significant change is observed in the oxygen content. A similar trend in stress evolution;with bias is also observed in Cr films capped with Al to protect from postdeposition oxidation. It is concluded that, for a given deposition condition, the incorporation of oxygen may lower the magnitude of tensile stress without affecting the trends in stress evolution with increasing substrate bias. These effects are discussed using a model that correlates the film microstructure with long range attractive forces predicted from interatomic potentials. (C) 2000 American Vacuum Society. [S0734-2101(00)03705-2]. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Misra, A (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MS K765, Los Alamos, NM 87545 USA. RI Misra, Amit/H-1087-2012 NR 18 TC 8 Z9 8 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2000 VL 18 IS 5 BP 2517 EP 2521 DI 10.1116/1.1286393 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 356GD UT WOS:000089434800074 ER PT J AU Mammana, VP Anders, S Monteiro, OR Salvadori, MC AF Mammana, VP Anders, S Monteiro, OR Salvadori, MC TI Investigation of the electron emission from pores in a diamond porous membrane SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID CATHODIC ARC DEPOSITION; FIELD-EMISSION; FILMS; CARBON; FABRICATION; PERFORMANCE; EMITTERS; AU AB It was previously proposed that porous diamond membranes can be used as held emission arrays. As main features of such a device, we identified a field enhancement factor equivalent or superior to that of a metal edge emitter, allied to a higher vacuum conductance. Emitting membrane prototypes were built and tested. These showed promising emission performance. In this work we continue the membrane pore characterization from a geometric point of view. Pie also present photoemission electron microscopy images from the emitting area around a pore. These images show that indeed there is enhanced electron emission occurring in that region. Current versus time and current versus field graphs complete the emission characterization. (C) 2000 American Vacuum Society. [S0734-211X(00)00105-0]. C1 Univ Sao Paulo, Inst Phys, Sao Paulo, Brazil. Lawrence Berkeley Lab, Berkeley, CA USA. RP Mammana, VP (reprint author), Univ Sao Paulo, Inst Phys, Sao Paulo, Brazil. RI Salvadori, Maria Cecilia/A-9379-2013; Raoux, Simone/G-3920-2016 NR 24 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD SEP-OCT PY 2000 VL 18 IS 5 BP 2415 EP 2419 DI 10.1116/1.1288133 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 365LB UT WOS:000089951800015 ER PT J AU Tucek, JC Krauss, AR Gruen, DM Auciello, O Moldovan, N Mancini, DC Zurn, S Polla, D AF Tucek, JC Krauss, AR Gruen, DM Auciello, O Moldovan, N Mancini, DC Zurn, S Polla, D TI Development of edge field emission cold cathodes based on low work function Cu-Li alloy coatings SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID MICROCATHODE ARRAYS; EMITTER ARRAY; FABRICATION; DEPOSITION; SURFACES; CARBON; FILMS; TIPS AB Vertical edge emitter arrays of thin walled (500-8000 Angstrom) hollow cylinders have been fabricated by the deposition of Cu-20 at.% Li alloy (Cu4Li) thin films on arrays of Si posts, followed by selective etching of the Si core. What remains is a hollow cylinder of Cu4Li, where the thickness of the emitting edge is determined by the deposited film thickness. Additionally, lateral edge emitters were fabricated from arrays of holes in SiO2 or Si3N4 films on flat Si surfaces. In this case, the emitting edge is formed by selectively overetching the Si beneath the hole, creating an edge from the overhang of the SiO2 (Si3N4) thin film upon which the Cu4Li alloy is deposited. The Cu,Li alloy provides a surface covered with a monolayer of Li atoms formed via Gibbsian segregation. The formation of Li-Cu atom dipoles on the surface of the alloy yields a work function lower than that of either a pure Li or Cu surface, resulting in enhanced electron emission and very low threshold fields. The alloy coating maintains a segregated monolayer of Li atoms on the surface even under adverse operational conditions, including ion bombardment of the surface. Edge emitters offer many potential advantages over the standard microtip arrays including ease of fabrication, higher emission currents per emitter due to the larger emission area of the edge, and greater physical robustness. The Cu4Li edge emitters exhibit threshold fields as low as E-0 = 5 V/mum, high current densities, and long-lived, stable emission. (C) 2000 American Vacuum Society. [S0734-211X(00)03805-1]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Expt Facil Div, Argonne, IL 60439 USA. Univ Minnesota, Minneapolis, MN 55455 USA. RP Tucek, JC (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 30 TC 3 Z9 3 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD SEP-OCT PY 2000 VL 18 IS 5 BP 2427 EP 2432 DI 10.1116/1.1308600 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 365LB UT WOS:000089951800018 ER PT J AU Mayer, TM de Boer, MP Shinn, ND Clews, PJ Michalske, TA AF Mayer, TM de Boer, MP Shinn, ND Clews, PJ Michalske, TA TI Chemical vapor deposition of fluoroalkylsilane monolayer films for adhesion control in microelectromechanical systems SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; SOLID-LIQUID INTERFACE; SILICA SURFACES; POLYSILICON; OCTADECYLTRICHLOROSILANE; SPECTROSCOPY; LAYER; GLASS AB We have developed a new process for applying a hydrophobic, low adhesion energy coating to microelectromechanical (MEMS) devices. Monolayer films are synthesized from tridecafluoro-1,1,2,2- tetrahydrooctyltrichlorosilane (FOTS) and water vapor in a low-pressure chemical vapor deposition process at room temperature. Film thickness is self-limiting by virtue of the inability of precursors to stick to the fluorocarbon surface of the film once it has formed. We have measured film densities of similar to3 molecules nm(2) and film thickness of similar to1 nm. Films are hydrophobic, with a water contact angle >110 degrees. We have also incorporated an in situ downstream microwave plasma cleaning process, which provides a clean, reproducible oxide surface prior to film deposition. Adhesion tests on coated and uncoated MEMS test structures demonstrate superior performance of the FOTS coatings. Cleaned, uncoated cantilever beam structures exhibit high adhesion energies in a high humidity environment. An adhesion energy of 100 mJ m(-2) is observed after exposure to >90% relative humidity. Fluoroalkylsilane coated beams exhibit negligible adhesion at low humidity and less than or equal to 20 muJ m(-2) adhesion energy at >90% relative humidity. No obvious film degradation was observed for films exposed to >90% relative humidity at room temperature for similar to 24 h. (C) 2000 American Vacuum Society. [S0734-211X(00)00705-8]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Mayer, TM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI de Boer, Maarten/C-1525-2013 OI de Boer, Maarten/0000-0003-1574-9324 NR 36 TC 89 Z9 90 U1 4 U2 35 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD SEP-OCT PY 2000 VL 18 IS 5 BP 2433 EP 2440 DI 10.1116/1.1288200 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 365LB UT WOS:000089951800019 ER PT J AU Webby, RJ Swenson, SL Krauss, SL Gerrish, PJ Goyal, SM Webster, RG AF Webby, RJ Swenson, SL Krauss, SL Gerrish, PJ Goyal, SM Webster, RG TI Evolution of swine H3N2 influenza viruses in the United States SO JOURNAL OF VIROLOGY LA English DT Article ID A VIRUSES; GENETIC REASSORTMENT; PIGS; TRANSMISSION; HUMANS; INFECTION; EMERGENCE; ORIGIN; CHILD; H1N1 AB During 1998, severe outbreaks of influenza were observed in four swine herds in the United States. This event was unique because the causative agents, H3N2 influenza viruses, are infrequently isolated from swine in North America. Two antigenically distinct reassortant viruses (H3N2) were isolated from infected animals: a double-reassortant virus containing genes similar to those of human and swine viruses, and a triple-reassortant virus containing genes similar to those of human, swine, and avian influenza viruses (N. N. Zhou, D. A. Senne, J. S. Landgraf, S. L. Swenson, G. Erickson, K. Rossow, L. Liu, K.-J. Yoon, S. Krauss, and R. G. Webster, J. Virol. 73:8851-8856, 1999). Because the U.S. pig population was essentially naive in regard to H3N2 viruses, it was important to determine the extent of viral spread. Hemagglutination inhibition (HI) assays of 4,382 serum samples from swine in 23 states indicated that 28.3% of these animals had been exposed to classical swine-like H1N1 viruses and 20.5% had been exposed to the triple-reassortant-like H3N2 viruses. The HI data suggested that viruses antigenically related to the double-reassortant H3N2 virus have not become widespread in the U.S. swine population. The seroreactivity levels in swine serum samples and the nucleotide sequences of six additional 1999 isolates, all of which were of the triple-reassortant genotype, suggested that H3N2 viruses containing avian PA and PB2 genes had spread throughout much of the country. These avian-like genes cluster with genes from North American avian viruses. The worldwide predominance of swine viruses containing an avian-like internal gene component suggests that these genes may confer a selective advantage in pigs. Analysis of the 1999 swine H3N2 isolates showed that the internal gene complex of the triple-reassortant viruses was associated with three recent phylogenetically distinct human-like hemagglutinin (HA) molecules. Acquisition of HU genes from the human virus reservoir will significantly affect the efficacy of the current swine H3N2 vaccines. This finding supports continued surveillance of U.S. swine populations for influenza virus activity. C1 St Jude Childrens Res Hosp, Dept Virol & Mol Biol, Memphis, TN 38105 USA. USDA, Natl Vet Serv Labs, Ames, IA 50010 USA. Univ Calif Los Alamos Natl Lab, Dept Theoret Biol & Biophys, Los Alamos, NM 87545 USA. Univ Minnesota, St Paul, MN 55108 USA. Univ Tennessee, Ctr Hlth Sci, Dept Pathol, Memphis, TN 38163 USA. RP Webster, RG (reprint author), St Jude Childrens Res Hosp, Dept Virol & Mol Biol, 332 N Lauderdale St, Memphis, TN 38105 USA. OI Gerrish, Philip/0000-0001-6393-0553 FU NCI NIH HHS [CA-21765, P30 CA021765]; NIAID NIH HHS [AI29680, N01AI95357] NR 40 TC 240 Z9 267 U1 1 U2 9 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0022-538X J9 J VIROL JI J. Virol. PD SEP PY 2000 VL 74 IS 18 BP 8243 EP 8251 DI 10.1128/JVI.74.18.8243-8251.2000 PG 9 WC Virology SC Virology GA 347ML UT WOS:000088933700004 PM 10954521 ER PT J AU Krishnan, VV Cosman, M AF Krishnan, VV Cosman, M TI Novel relaxation compensated method to measure proton exchange rates in biomolecules based on decorrelation of heteronuclear two-spin order SO MAGNETIC RESONANCE IN CHEMISTRY LA English DT Article DE NMR; H-1 NMR; N-15 NMR; biomolecule; water exchange; decorrelation; two-spin order ID NUCLEAR MAGNETIC-RESONANCE; ACID-BINDING PROTEIN; NMR-SPECTROSCOPY; BACKBONE DYNAMICS; CROSS-CORRELATION; IMPROVED SENSITIVITY; 2-DIMENSIONAL NMR; CHEMICAL-EXCHANGE; AMIDE PROTONS; 2-SPIN ORDER AB A combined experiment based on decorrelation of heteronuclear two-spin order and a new analysis method is presented for measuring accurate rapid amide proton exchange rates (k(ex)(HH) = k(ex)) in N-15-labeled biomolecules, such as proteins or nucleic acids, in water. The term 'decorrelation' is defined as the loss of the initial correlation between a labile biomolecule proton and its coupled nitrogen when they are separated by intermolecular chemical exchange with water. The NMR pulse sequence [DECORrelated EXchange SpectroscropY (DECOREXSY)] measures the decay of the heteronuclear two-spin order terms with minimal interference effects from relaxation processes and solvent-induced artifacts. The new analysis protocol based on backbone relaxation measurements is introduced to compensate for relaxation contributions to the exchange rates that are otherwise inseparable. This simple and straightforward scheme has several potential applications in protein folding and biomolecular recognition and binding studies, and fills the need for a sensitive experiment to measure absolute fast-amide proton exchange rates predominantly on the sub-millisecond time-scale. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program L 448, Livermore, CA 94551 USA. RP Krishnan, VV (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program L 448, 7000 East Ave, Livermore, CA 94551 USA. RI Krishnan, Krish/A-6859-2010 NR 53 TC 1 Z9 1 U1 0 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0749-1581 J9 MAGN RESON CHEM JI Magn. Reson. Chem. PD SEP PY 2000 VL 38 IS 9 BP 789 EP 794 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 349DE UT WOS:000089027900013 ER PT J AU Hyman, JM Li, J AF Hyman, JM Li, J TI An intuitive formulation for the reproductive number for the spread of diseases in heterogeneous populations SO MATHEMATICAL BIOSCIENCES LA English DT Article; Proceedings Paper CT Alcala 1st International Conference on Mathematical Ecology CY SEP 04-08, 1998 CL MADRID, SPAIN DE epidemiology; mathematical model; threshold conductors; reproductive number; transmission dynamics; endemic equilibrium; dynamical systems; stability ID SEXUALLY-TRANSMITTED DISEASES; INFECTIOUS-DISEASES; TRANSMISSION DYNAMICS; HIV TRANSMISSION; BEHAVIOR-CHANGE; HOMOSEXUAL MEN; MODELS; RATIO; VACCINATION; PREVALENCE AB The thresholds for mathematical epidemiology models specify the critical conditions for an epidemic to grow or die out. The reproductive number can provide significant insight into the transmission dynamics of a disease and can guide strategies to control its spread. We define the mean number of contacts, the mean duration of infection, and the mean transmission probability appropriately for certain epidemiological models, and construct a simplified formulation of the reproductive number as the product of these quantities, When the spread of the epidemic depends strongly upon the heterogeneity of the populations, the epidemiological models must account for this heterogeneity, and the expressions for the reproductive number become correspondingly more complex. We formulate several models with different heterogeneous structures and demonstrate how to define the mean quantities for an explicit expression for the reproductive number. In complex heterogeneous models, it seems necessary to define the reproductive number for each structured subgroup or cohort and then use the average of these reproductive numbers weighted by their heterogeneity to estimate the reproductive number for the total population. (C) 2000 Elsevier Science Inc. All rights reserved. C1 Univ Alabama, Dept Math Sci, Huntsville, AL 35899 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Div Theoret, Los Alamos, NM 87545 USA. RP Li, J (reprint author), Univ Alabama, Dept Math Sci, Huntsville, AL 35899 USA. NR 42 TC 59 Z9 68 U1 2 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0025-5564 J9 MATH BIOSCI JI Math. Biosci. PD SEP PY 2000 VL 167 IS 1 BP 65 EP 86 DI 10.1016/S0025-5564(00)00025-0 PG 22 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA 347EJ UT WOS:000088914200006 PM 10942787 ER PT J AU Christensen, RM AF Christensen, RM TI Yield functions, damage states, and intrinsic strength SO MATHEMATICS AND MECHANICS OF SOLIDS LA English DT Article DE yield functions; Mises criterion; intrinsic strength; ductile-brittle transition ID NUCLEATION; CRACK AB A recently derived isotropic yield/failure criterion is here shown to give a measure of the state of the damage relative to an intrinsic (ideal) yield strength. The formulation of the intrinsic strength itself is obtained through a spectral analysis. A criterion for the ductile-brittle transition is found in the process of deriving the effect of pressure on the new yield function formalism. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Stanford Univ, Stanford, CA 94305 USA. RP Christensen, RM (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94550 USA. NR 10 TC 13 Z9 13 U1 0 U2 1 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 1081-2865 J9 MATH MECH SOLIDS JI Math. Mech. Solids PD SEP PY 2000 VL 5 IS 3 BP 285 EP 300 DI 10.1177/108128650000500302 PG 16 WC Materials Science, Multidisciplinary; Mathematics, Interdisciplinary Applications; Mechanics SC Materials Science; Mathematics; Mechanics GA 417DQ UT WOS:000167820500002 ER PT J AU Christensen, RM AF Christensen, RM TI Compressive failure of composites using a matrix-controlled failure criterion with the kink band mechanism SO MECHANICS OF MATERIALS LA English DT Article DE fiber composites; compressive failure; kink bands ID FIBER COMPOSITES; STRENGTH AB Concerning the compressive strength of fiber composites, the kink band mechanism is combined with a recently derived stress-based, matrix-controlled failure criterion. Resulting predictions are given for the load level and kink band inclination angle at kink formation. The results are in accordance with other widely different approaches, providing some corroboration for this new failure criterion. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Div Mat Sci & Technol, Livermore, CA 94551 USA. Stanford Univ, Dept Aeronaut & Astronaut, Stanford, CA 94305 USA. RP Christensen, RM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Div Mat Sci & Technol, POB 808,Mail Stop L-355, Livermore, CA 94551 USA. NR 11 TC 3 Z9 3 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6636 J9 MECH MATER JI Mech. Mater. PD SEP PY 2000 VL 32 IS 9 BP 505 EP 509 DI 10.1016/S0167-6636(00)00014-4 PG 5 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 343WG UT WOS:000088725000001 ER PT J AU Breeden, WK McPherson, DW AF Breeden, WK McPherson, DW TI Response to "Comment on 'In vivo biodistribution of (IPIP)-I-125 and internal dosimetry of (IPIP)-I-123 radioiodinated agents selective to the muscarinic acetylcholinergic receptor complex'" SO MEDICAL PHYSICS LA English DT Letter C1 Med Phys Consultants Inc, Indianapolis, IN 46240 USA. Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN 37831 USA. RP Breeden, WK (reprint author), Med Phys Consultants Inc, Indianapolis, IN 46240 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD SEP PY 2000 VL 27 IS 9 BP 2191 EP 2191 DI 10.1118/1.1289901 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 355VX UT WOS:000089410200025 ER PT J AU Ice, GE Sparks, CJ AF Ice, GE Sparks, CJ TI Anomalous (resonant) diffuse x-ray scattering measurements of local correlations in disordered solid-solution alloys SO METALLOFIZIKA I NOVEISHIE TEKHNOLOGII LA English DT Article DE local chemical order; short-range order; size effect; static atomic displacements; x-ray diffuse scattering; anomalous (resonant) x-ray scattering ID ORDER; DISPLACEMENTS AB With resonant (anomalous) x-ray scattering the x-ray scattering contrast between elements can be controlled to high-light local correlations in solid-solution alloys. For some binary solid-solution alloys, three diffuse-scattering maps allow the scattering from short-ranged chemical correlations, had the three individual pair static atomic displacements to be separated from the thermal diffuse scattering (TDS). For elements A and B that are nearly in the periodic table, the scattering contrast, f(A)-f(B), can be made positive, negative or nearly Zero by tuning the x-ray energy. This allows unprecedented sensitivity to static atomic displacements. Uncertainties in the static displacements < 0.0001 rtm or better out to the 10th shell can be achieved. Measurements on Fe-Ni-Cr binary alloys and others show systematic trends not predicted by previous measurements or theories. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Ice, GE (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 24 TC 2 Z9 2 U1 0 U2 4 PU NATL ACAD SCIENCES UKRAINE, INST METAL PHYSICS PI KIEV 142 PA 36 ACADEMICIAN VERNADSKY BLVD, KIEV 142 UA-252180, UKRAINE SN 1024-1809 J9 METALLOFIZ NOV TEKH+ JI Metallofiz. Nov. Tekhnol.-Met. Phys. Adv. Techn. PD SEP PY 2000 VL 22 IS 9 BP 17 EP 24 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 374KF UT WOS:000165343800004 ER PT J AU Engler, O Huh, MY Tome, CN AF Engler, O Huh, MY Tome, CN TI A study of through-thickness texture gradients in rolled sheets SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID ROLLING TEXTURES; CRYSTALLOGRAPHIC TEXTURE; FCC METALS; RECRYSTALLIZATION TEXTURES; STAINLESS-STEEL; DEFORMATION; EVOLUTION; INHOMOGENEITY; LUBRICATION; ALUMINUM AB A method to simulate shear effects and through-thickness texture gradients in rolled sheet materials is introduced. The strain history during a rolling pass is idealized by superimposing a sine-shaped evolution of the <(epsilon)over bar>(13) shear component to a plane-strain state. These generic strain histories are enforced in a visco-plastic self-consistent (VPSC) polycrystal deformation model to simulate texture evolution as a function of through-thickness position. The VPSC scheme is deemed superior to a full constraints (FC) or relaxed constraints (RC) approach, because it allows one to fully prescribe diagonal and shear-strain-rate components while still accounting for grain-shape effects. The idealized strain states are validated by comparison with deformation histories obtained through finite-element method (FEM) calculations. The through-thickness texture gradients are accounted for by introducing a relative variation of the sine-shaped <(epsilon)over bar>(13) shear with respect to the plane-strain component. The simulation results are validated, in turn, by comparison with typical examples of through-thickness texture gradients observed experimentally in rolled plates and in sheets of fee and bcc materials. C1 Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, MST 8, Los Alamos, NM 87545 USA. Korea Univ, Div Mat Sci & Engn, Seoul 136701, South Korea. RP Engler, O (reprint author), Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, MST 8, POB 1663, Los Alamos, NM 87545 USA. RI Tome, Carlos/D-5058-2013 NR 51 TC 129 Z9 133 U1 3 U2 35 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2000 VL 31 IS 9 BP 2299 EP 2315 DI 10.1007/s11661-000-0146-7 PG 17 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352DB UT WOS:000089198300019 ER PT J AU Caffee, MW Nishiizumi, K Matsumoto, Y Matsuda, J Komura, K Nakamura, N AF Caffee, MW Nishiizumi, K Matsumoto, Y Matsuda, J Komura, K Nakamura, N TI Noble gases and cosmogenic radionuclides in the Kobe CK meteorite. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID CHONDRITES C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Osaka Univ, Dept Earth & Space Sci, Osaka, Japan. Kanazawa Univ, Low Level Radioact Lab, Kanazawa, Ishikawa 920, Japan. Kobe Univ, Dept Earth & Planetary Sci, Kobe, Hyogo 657, Japan. NR 4 TC 3 Z9 3 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A37 EP A38 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400046 ER PT J AU Gounelle, M Shu, FH Shang, S Glassgold, AE Rehm, KE Lee, T AF Gounelle, M Shu, FH Shang, S Glassgold, AE Rehm, KE Lee, T TI Extinct radioactivities in meteorites and protosolar cosmic rays: The effect of self-shielding. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Ctr Spectrometrie Nucl & Spectrometrie Masse, F-91405 Orsay, France. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60431 USA. Acad Sinica, Inst Earth Sci, Taipei 115, Taiwan. RI Lee, Typhoon/N-8347-2013 NR 7 TC 1 Z9 1 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A62 EP A62 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400094 ER PT J AU Jones, RH Durakiewicz, T Sharp, ZD Schilk, AJ AF Jones, RH Durakiewicz, T Sharp, ZD Schilk, AJ TI Oxygen-isotopic ratios of bulk chondrules from the Mokoia CV3 chondrite. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Univ New Mexico, Inst Meteorit, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A84 EP A85 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400137 ER PT J AU Lavielle, B Gilabert, E Marti, K Nishiizumi, K Caffee, M AF Lavielle, B Gilabert, E Marti, K Nishiizumi, K Caffee, M TI Collisional history in irons: Interpreting the cosmic-ray records. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID EXPOSURE AGES; METEORITES; AL-26; BE-10 C1 CEN Bordeaux Gradignan, Unit Mixte Rech 5084, Lab Chim Nucl Analyt & Bioenvironm, F-33175 Gradignan, France. Univ Calif San Diego, Dept Chem & Biochem, La Jolla, CA 92093 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 6 TC 1 Z9 1 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A96 EP A96 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400159 ER PT J AU Leckrone, KJ Pellin, MJ Davis, AM Lewis, RS Amari, S Clayton, RN AF Leckrone, KJ Pellin, MJ Davis, AM Lewis, RS Amari, S Clayton, RN TI Correlations among light and heavy element isotopic compositions in individual mainstream silicon carbide grains SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID PRIMITIVE METEORITES; NUCLEOSYNTHESIS; MAGNESIUM; TITANIUM C1 Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Washington Univ, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. RI Pellin, Michael/B-5897-2008 OI Pellin, Michael/0000-0002-8149-9768 NR 8 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A96 EP A97 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400160 ER PT J AU Marhas, KK Hutcheon, ID Krot, AN Goswami, JN Komatsu, M AF Marhas, KK Hutcheon, ID Krot, AN Goswami, JN Komatsu, M TI Aluminium-26 in carbonaceous chondrite chondrules. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Phys Res Lab, Ahmedabad 380009, Gujarat, India. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Hawaii, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. Max Planck Inst Chem, D-55020 Mainz, Germany. NR 9 TC 21 Z9 21 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A102 EP A102 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400172 ER PT J AU Masarik, J Nishiizumi, K Reedy, RC AF Masarik, J Nishiizumi, K Reedy, RC TI Simulation of cosmogenic noble gas production in ordinary chondrites and the lunar surface. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Komensky Univ, Dept Nucl Phys, SK-84215 Bratislava, Slovakia. Univ Calif Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Los Alamos, NM 87545 USA. NR 7 TC 3 Z9 4 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A104 EP A104 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400176 ER PT J AU Nishiizumi, K Caffee, MW Masarik, J AF Nishiizumi, K Caffee, MW Masarik, J TI Cosmogenic radionuclides in the Los Angeles martian meteorite. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. NR 3 TC 11 Z9 11 U1 0 U2 2 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A120 EP A120 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400206 ER PT J AU Reed, GW AF Reed, GW TI The cosmochemical behavior of mercury. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NR 9 TC 3 Z9 3 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A133 EP A134 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400232 ER PT J AU Trombka, JI Nittler, LR Boynton, WV Bruckner, J Squyres, SW Arnold, JR Evans, LG Gorenstein, P Hurley, KC McCoy, TJ Reedy, RC Bailey, S Burbine, TH Bhangoo, JS Clark, PE Floyd, SR Gold, RE McClanahan, TP McCartney, E Goldsten, JO McNutt, RL Mikheeva, I Murphy, ME Starr, RD AF Trombka, JI Nittler, LR Boynton, WV Bruckner, J Squyres, SW Arnold, JR Evans, LG Gorenstein, P Hurley, KC McCoy, TJ Reedy, RC Bailey, S Burbine, TH Bhangoo, JS Clark, PE Floyd, SR Gold, RE McClanahan, TP McCartney, E Goldsten, JO McNutt, RL Mikheeva, I Murphy, ME Starr, RD TI The chemical composition of asteroid 433 Eros: Preliminary results of the NEAR Shoemaker X-Ray/Gamma-Ray Spectrometer. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Max Planck Inst Chem, D-55020 Mainz, Germany. Cornell Univ, Ithaca, NY 14853 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Comp Sci Corp, Syst Sci Div, Laurel, MD 20707 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Univ Calif Berkeley, Space Sci Lab 7450, Berkeley, CA 94720 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RI McNutt, Ralph/E-8006-2010 OI McNutt, Ralph/0000-0002-4722-9166 NR 6 TC 0 Z9 0 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A159 EP A160 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400284 ER PT J AU Wolf, SF Friedrich, JM AF Wolf, SF Friedrich, JM TI Labile-trace-element determination by high-resolution inductively coupled plasma mass spectrometry. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A171 EP A171 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400305 ER PT J AU Radhakrishnan, B Sarma, G Weiland, H Baggethun, P AF Radhakrishnan, B Sarma, G Weiland, H Baggethun, P TI Simulations of deformation and recrystallization of single crystals of aluminium containing hard particles SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID MONTE-CARLO SIMULATION; EVOLUTION AB The deformation of a single crystal of aluminium in the Goss orientation [011](100) containing a coarse particle of silicon was modelled by using a finite-element (FE) code based on the crystal plasticity approach. The simulations clearly captured the heterogeneous deformation of the aluminium matrix, resulting in a region of high deformation in the vicinity of the hard particle, surrounded by a region where the amount of deformation was significantly lower. The evolution of the corresponding deformation substructure during annealing was simulated using a Monte Carlo technique. The simulations clearly demonstrated the discontinuous evolution of the subgrains in the deformation zone to form recrystallization nuclei around the hard particle, and the subsequent growth of these nuclei to consume the matrix region around the particle. For plane strain compression up to epsilon(zz) = -0.4 that was used in this study, the deformation texture components near the particle consisted of rotations up to 20 degrees from the initial Goss orientation about the transverse direction. Recrystallization simulations captured the formation and growth of nuclei from the deformation heterogeneities existing near the hard particle and predicted a significant strengthening of the orientations present in the particle deformation zone. The simulation results are shown to capture many of the experimentally observed features of deformation and recrystallization textures in aluminium single crystals containing coarse particles of silicon. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Alcoa Tech Univ, Alcoa Center, PA 15069 USA. RP Radhakrishnan, B (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. NR 17 TC 25 Z9 26 U1 0 U2 9 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD SEP PY 2000 VL 8 IS 5 BP 737 EP 750 DI 10.1088/0965-0393/8/5/307 PG 14 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 365AF UT WOS:000089925700007 ER PT J AU Takata, M Sasaki, MS Sonoda, E Fukushima, T Morrison, C Albala, JS Swagemakers, SMA Kanaar, R Thompson, LH Takeda, S AF Takata, M Sasaki, MS Sonoda, E Fukushima, T Morrison, C Albala, JS Swagemakers, SMA Kanaar, R Thompson, LH Takeda, S TI The Rad51 paralog Rad51B promotes homologous recombinational repair SO MOLECULAR AND CELLULAR BIOLOGY LA English DT Article ID STRAND BREAK REPAIR; RECA-LIKE PROTEINS; SACCHAROMYCES-CEREVISIAE; DNA-REPAIR; VERTEBRATE CELLS; NUCLEAR FOCI; MAMMALIAN-CELLS; COMPLEX-FORMATION; PROKARYOTIC RECA; GENE CONVERSION AB The highly conserved Saccharomyces cerevisiae Rad51 protein plays a central role in both mitotic and meiotic homologous DNA recombination. Seven members of the Rad51 family have been identified in vertebrate cells, including Rad51, Dmc1, and five Rad51-related proteins referred to as Rad51 paralogs, which share 20 to 30% sequence identity with Rad51. In chicken B lymphocyte DT40 cells, we generated a mutant with RAD51B/RAD51L1, a member of the Rad51 family, knocked out. RAD51B(-/-) cells are viable, although spontaneous chromosomal aberrations kill about 20% of the cells in each cell cycle. Rad51B deficiency impairs homologous recombinational repair (HRR), as measured by targeted integration, sister chromatid exchange, and intragenic recombination at the immunoglobulin locus. RAD51B(-/-) cells are quite sensitive to the cross-linking agents cisplatin and mitomycin C and mildly sensitive to gamma-rays. The formation of damage-induced Rad51 nuclear foci is much reduced in RAD51B(-/-) cells, suggesting that Rad51B promotes the assembly of Rad51 nucleoprotein filaments during HRR. These findings show that Rad51B is important for repairing various types of DNA lesions and maintaining chromosome integrity. C1 Kyoto Univ, Fac Med, CREST Res Project, Japan Sci & Technol,Sakyo Ku, Kyoto 6068501, Japan. Kyoto Univ, Ctr Radiat Biol, Kyoto 6068501, Japan. Erasmus Univ, Dept Cell Biol & Genet, Ctr Med Genet, NL-3000 DR Rotterdam, Netherlands. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Takeda, S (reprint author), Kyoto Univ, Fac Med, CREST Res Project, Japan Sci & Technol,Sakyo Ku, Konoe Yoshida, Kyoto 6068501, Japan. RI Morrison, Ciaran/B-6568-2008 OI Morrison, Ciaran/0000-0003-2401-7029 NR 67 TC 186 Z9 190 U1 1 U2 7 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0270-7306 J9 MOL CELL BIOL JI Mol. Cell. Biol. PD SEP PY 2000 VL 20 IS 17 BP 6476 EP 6482 DI 10.1128/MCB.20.17.6476-6482.2000 PG 7 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 343RZ UT WOS:000088716500030 PM 10938124 ER PT J AU Kreher, SA Fore, SA Collins, BS AF Kreher, SA Fore, SA Collins, BS TI Genetic variation within and among patches of the clonal species, Vaccinium stamineum L. SO MOLECULAR ECOLOGY LA English DT Article DE clonal; clone identification; genetic diversity; RAPD; Vaccinium stamineum ID POLYMORPHIC DNA RAPD; GENOTYPIC DIVERSITY; SPATIAL-DISTRIBUTION; NATURAL-POPULATIONS; POPULUS-TREMULOIDES; TREMBLING ASPEN; SEED PRODUCTION; MARKERS; DYNAMICS; SHRUB AB Once thought to be dominated by a few genets, clonal plant populations can contain high levels of genetic diversity. Sexual reproduction and vegetative growth strategy affect the amount and distribution of genetic diversity within clonal plant populations. We determined the scale of genetic diversity in a population of Vaccinium stamineum, a clonal shrub that forms discrete patches. Using the random amplified polymorphic DNA (RAPD) technique, we surveyed the genetic diversity of V. stamineum within and among patches from a 1-ha site. We found 67 unique RAPD profiles among the 99 sampled individuals from 22 patches. In two patches, all the sampled individuals had the same RAPD profile. In seven patches, every individual sampled had a different RAPD profile. The remaining patches showed mixed RAPD profiles which suggested both clonal and sexual reproduction. Each unique RAPD profile was restricted to one patch (with one exception), which suggests that clonal growth occurs at the patch scale. High levels of genetic variation within some patches may be explained by somatic mutation; however, seedling recruitment is a more likely explanation. C1 Truman State Univ, Div Sci, Kirksville, MO 63501 USA. Savannah River Ecol Lab, Aiken, SC USA. RP Fore, SA (reprint author), Truman State Univ, Div Sci, Kirksville, MO 63501 USA. NR 32 TC 53 Z9 58 U1 0 U2 10 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD SEP PY 2000 VL 9 IS 9 BP 1247 EP 1252 DI 10.1046/j.1365-294x.2000.01002.x PG 6 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 356BM UT WOS:000089424200007 PM 10972765 ER PT J AU Sharf, Y Cory, DG Somaroo, SS Havel, TF Knill, E Laflamme, R Zurek, WH AF Sharf, Y Cory, DG Somaroo, SS Havel, TF Knill, E Laflamme, R Zurek, WH TI A study of quantum error correction by geometric algebra and liquid-state NMR spectroscopy SO MOLECULAR PHYSICS LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; PRODUCT OPERATOR-FORMALISM; COUPLED SPIN SYSTEMS; MULTISPIN SYSTEMS; PULSE EXPERIMENTS; COMPUTATION; DECOHERENCE; RELAXATION; COMPUTER; ALGORITHM AB Quantum error correcting codes enable the information contained in a quantum state to be protected from decoherence due to external perturbations. Applied to NMR, this procedure does not alter normal relaxation, but rather converts the state of a 'data' spin into multiple quantum coherences involving additional ancilla spins. These multiple quantum coherences relax at differing rates, thus permitting the original state of the data to be approximately reconstructed by mixing them together in an appropriate fashion. This paper describes the operation of a simple, three-bit quantum code in the product operator formalism, and uses geometric algebra methods to obtain the error-corrected decay curve in the presence of arbitrary correlations in the external random fields. These predictions are confirmed in both the totally correlated and uncorrelated cases by liquid-state NMR experiments on C-13-labelled alanine, using gradient- diffusion methods to implement these idealized decoherence models. Quantum error correction in weakly polarized systems requires that the ancilla spins be prepared in a pseudo-pure state relative to the data spin, which entails a loss of signal that exceeds any potential gain through error correction. Nevertheless, this study shows that quantum coding can be used to validate theoretical decoherence mechanisms, and to provide detailed information on correlations in the underlying NMR relaxation dynamics. C1 Harvard Univ, Sch Med, BCMP, Boston, MA 02115 USA. MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Havel, TF (reprint author), Harvard Univ, Sch Med, BCMP, 240 Longwood Ave, Boston, MA 02115 USA. NR 43 TC 18 Z9 18 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD SEP PY 2000 VL 98 IS 17 BP 1347 EP 1363 DI 10.1080/002689700413604 PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 342WM UT WOS:000088668400008 ER PT J AU Weiss, S AF Weiss, S TI Measuring conformational dynamics of biomolecules by single molecule fluorescence spectroscopy SO NATURE STRUCTURAL BIOLOGY LA English DT Review ID RESONANCE ENERGY-TRANSFER; ROOM-TEMPERATURE; ATP SYNTHASE; LIGHT-CHAIN; POLARIZATION; ROTATION; PROTEIN; FLUOROPHORE; FLUCTUATIONS; MICROSCOPY AB Dynamic structural changes of macromolecules undergoing biochemical reactions can be studied using novel single molecule spectroscopy tools. Recent advances applying such distance and orientation molecular rulers to biological systems are reviewed, and future prospects and challenges are discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Weiss, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI weiss, shimon/B-4164-2009 OI weiss, shimon/0000-0002-0720-5426 NR 51 TC 431 Z9 437 U1 9 U2 90 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD SEP PY 2000 VL 7 IS 9 BP 724 EP 729 DI 10.1038/78941 PG 6 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 350AQ UT WOS:000089078500010 PM 10966638 ER PT J AU Liu, K Cho, HS Lashuel, HA Kelly, JW Wemmer, DE AF Liu, K Cho, HS Lashuel, HA Kelly, JW Wemmer, DE TI A glimpse of a possible amyloidogenic intermediate of transthyretin SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID HYDROGEN-EXCHANGE; FIBRIL FORMATION; ALZHEIMERS-DISEASE; ACID DENATURATION; PROTEINS; NMR; VARIANTS; INVITRO; STATE AB Studies have indicated that partially unfolded states occur under conditions that favor amyloid formation by transthyretin (TTR), as well as other amyloidogenic proteins. In this study, we used hydrogen exchange measurements to show that there is selective destabilization of one half of the beta-sandwich structure of TTR under such conditions. This provides more direct information about conformational fluctuations than previously available, and will facilitate design of future experiments to probe the intermediates critical to amyloid formation. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Phys Biosci, Berkeley, CA 94720 USA. Scripps Res Inst, Skaggs Inst Chem Biol, La Jolla, CA 92037 USA. RP Wemmer, DE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, MC-1460, Berkeley, CA 94720 USA. NR 30 TC 125 Z9 125 U1 1 U2 5 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD SEP PY 2000 VL 7 IS 9 BP 754 EP 757 PG 4 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 350AQ UT WOS:000089078500016 PM 10966644 ER PT J AU Gandhi, CS Loots, E Isacoff, EY AF Gandhi, CS Loots, E Isacoff, EY TI Reconstructing voltage sensor-pore interaction from a fluorescence scan of a voltage-gated K+ channel SO NEURON LA English DT Article ID SHAKER POTASSIUM CHANNELS; C-TYPE INACTIVATION; SELECTIVITY FILTER; S4 SEGMENT; SLOW INACTIVATION; GATING CURRENTS; CHARGE MOVEMENT; SODIUM-CHANNELS; MOLECULAR-BASIS; ION CHANNELS AB X-ray crystallography has made considerable recent progress in providing static structures of ion channels. Here we describe a complementary method-systematic fluorescence scanning-that reveals the structural dynamics of a channel. Local protein motion was measured from changes in the fluorescent intensity of a fluorophore attached at one of 37 positions in the pore domain and in the S4 voltage sensor of the Shaker K+ channel. The local rearrangements that accompany activation and slow inactivation were mapped onto the homologous structure of the KcsA channel and onto models of S4. The results place clear constraints on S4 location, voltage-dependent movement, and the mechanism of coupling of S4 motion to the operation of the slow inactivation gate in the pore domain. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Cell & Mol Biol, Phys Biosci Div, Berkeley, CA 94720 USA. RP Isacoff, EY (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Cell & Mol Biol, Phys Biosci Div, 271 Life Sci Addit, Berkeley, CA 94720 USA. FU NINDS NIH HHS [NS3549, R01 NS035549-05] NR 68 TC 81 Z9 82 U1 0 U2 0 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 USA SN 0896-6273 J9 NEURON JI Neuron PD SEP PY 2000 VL 27 IS 3 BP 585 EP 595 DI 10.1016/S0896-6273(00)00068-4 PG 11 WC Neurosciences SC Neurosciences & Neurology GA 359FR UT WOS:000089601300021 PM 11055440 ER PT J AU Goodman, JH Yang, WL Barth, RF Gao, ZX Boesel, CP Staubus, AE Gupta, N Gahbauer, RA Adams, DM Gibson, CR Ferketich, AK Moeschberger, ML Soloway, AH Carpenter, DE Albertson, BJ Bauer, WF Zhang, MZ Wang, CC AF Goodman, JH Yang, WL Barth, RF Gao, ZX Boesel, CP Staubus, AE Gupta, N Gahbauer, RA Adams, DM Gibson, CR Ferketich, AK Moeschberger, ML Soloway, AH Carpenter, DE Albertson, BJ Bauer, WF Zhang, MZ Wang, CC TI Boron neutron capture therapy of brain tumors: Biodistribution, pharmacokinetics, and radiation dosimetry of sodium borocaptate in patients with gliomas SO NEUROSURGERY LA English DT Article; Proceedings Paper CT 4th Annual Meeting of the Society-for-Neuro-Oncology CY NOV 19-21, 1999 CL SCOTTSDALE, ARIZONA SP Soc Neuro Oncol DE biodistribution; boron neutron capture therapy; sodium borocaptate ID ATOMIC EMISSION-SPECTROSCOPY; GLIOBLASTOMA-MULTIFORME; INTRACAROTID INJECTION; EORTC PROTOCOL-11961; INTRACRANIAL TUMORS; BARRIER DISRUPTION; NA2B12H11SH BSH; CLINICAL-TRIAL; PHASE-I; BNCT AB OBJECTIVE: The purpose of this study was to obtain tumor and normal brain tissue biodistribution data and pharmacokinetic profiles for sodium borocaptate (Na2B12H11SH) (BSH), a drug that has been used clinically in Europe and Japan for boron neutron capture therapy of brain tumors. The study was performed with a group of 25 patients who had preoperative diagnoses of either glioblastoma multiforme (GBM) or anaplastic astrocytoma (AA) and were candidates for debulking surgery. Nineteen of these patients were subsequently shown to have histopathologically confirmed diagnoses of GBM or AA, and they constituted the study population. METHODS: BSH (non-B-10-enriched) was infused intravenously, in a 1-hour period, at doses of 15, 25, and 50 mg boron/kg body weight (corresponding to 26.5, 44.1, and 88.2 mg BSH/kg body weight, respectively) to groups of 3, 3, and 13 patients, respectively. Multiple samples of tumor tissue, brain tissue around the tumors, and normal brain tissue were obtained at either 3 to 7 or 13 to 15 hours after infusion. Blood samples for pharmacokinetic studies were obtained at times up to 120 hours after termination of the infusion. Sixteen of the patients underwent surgery at the Beijing Neurosurgical Institute and three at The Ohio State University, where all tissue samples were subsequently analyzed for boron content by direct current plasma-atomic emission spectroscopy. RESULTS: Blood boron values peaked at the end of the infusion and then decreased triexponentially during the 120-hour sampling period. At 6 hours after termination of the infusion, these values had decreased to 20.8, 29.1, and 62.6 mu g/ml for boron doses of 15, 25, and 50 mg/kg body weight, respectively. For a boron dose of 50 mg/kg body weight, the maximum (mean +/- standard deviation) solid tumor boron values at 3 to 7 hours after infusion were 17.1 +/- 5.8 and 17.3 +/- 10.1 mu g/g for GBMs and AAs, respectively, and the mean tumor value averaged across all samples was 11.9 mu g/g for both GBMs and AAs. In contrast, the mean normal brain tissue values, averaged across all samples, were 4.6 +/- 5.1 and 5.5 +/- 3.9 mu g/g and the tumor/normal brain tissue ratios were 3.8 and 3.2 for patients with GBMs and AAs, respectively. The large standard deviations indicated significant heterogeneity in uptake in both tumor and normal brain tissue. Regions histopathologically classified either as a mixture of tumor and normal brain tissue or as infiltrating tumor exhibited slightly lower boron concentrations than those designated as solid tumor. After a dose of 50 mg/kg body weight, boron concentrations in blood decreased from 104 mu g/ml at 2 hours to 63 mu g/ml at 6 hours and concentrations in skin and muscle were 43.1 and 39.2 mu g/g, respectively, during the 3- to 7-hour sampling period. CONCLUSION: When tumor, blood, and normal tissue boron concentrations were taken into account, the most favorable tumor uptake data were obtained with a boron dose of 25 mg/kg body weight, 3 to 7 hours after termination of the infusion. Although blood boron levels were high, normal brain tissue boron levels were almost always lower than tumor levels. However, tumor boron concentrations were less than those necessary for boron neutron capture therapy, and there was significant intratumoral and interpatient variability in the uptake of BSH, which would make estimation of the radiation dose delivered to the tumor very difficult. It is unlikely that intravenous administration of a single dose of BSH would result in therapeutically useful levels of boron. However, combining BSH with boronophenylalanine, the other compound that has been used clinically, and optimizing their delivery could increase tumor boron uptake and potentially improve the efficacy of boron neutron capture therapy. C1 Ohio State Univ, Sch Publ Hlth, Dept Pathol, Columbus, OH 43210 USA. Ohio State Univ, Sch Publ Hlth, Div Neurol Surg, Columbus, OH 43210 USA. Ohio State Univ, Sch Publ Hlth, Div Radiat Oncol, Columbus, OH 43210 USA. Ohio State Univ, Sch Publ Hlth, Coll Pharm, Columbus, OH 43210 USA. Ohio State Univ, Sch Publ Hlth, Div Epidemiol & Biometr, Columbus, OH 43210 USA. Inst Neurosurg, Beijing, Peoples R China. Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. RP Barth, RF (reprint author), Ohio State Univ, Sch Publ Hlth, Dept Pathol, 1645 Neil Ave, Columbus, OH 43210 USA. RI Gupta, Nilendu/E-3171-2011; Bauer, William/B-8357-2016 OI Bauer, William/0000-0002-7190-9700 NR 47 TC 29 Z9 29 U1 2 U2 6 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0148-396X J9 NEUROSURGERY JI Neurosurgery PD SEP PY 2000 VL 47 IS 3 BP 608 EP 621 PG 14 WC Clinical Neurology; Surgery SC Neurosciences & Neurology; Surgery GA 349GJ UT WOS:000089037100032 PM 10981748 ER PT J AU Lapenta, G Brackbill, JU AF Lapenta, G Brackbill, JU TI 3D reconnection due to oblique modes: a simulation of Harris current sheets SO NONLINEAR PROCESSES IN GEOPHYSICS LA English DT Article; Proceedings Paper CT 24th General Assembly of the European-Geophysical-Society CY APR 19-23, 1999 CL THE HAGUE, NETHERLANDS SP European Geophys Soc ID DRIFT-KINK INSTABILITY; THIN CURRENT SHEETS; COLLISIONLESS RECONNECTION; PARTICLE SIMULATION; MAGNETIC RECONNECTION; KINETIC-THEORY; NEUTRAL SHEET; MAGNETOTAIL; FIELD; DISSIPATION AB Simulations in three dimensions of a Harris current sheet with mass ratio, m(i)/m(e) = 180, and current sheet thickness, p(i)/L = 0.5, suggest the existence of a linearly unstable oblique mode, which is independent from either the drift-kink or the tearing instability. The new oblique mode causes reconnection independently from the tearing mode. During the initial linear stage, the system is unstable to the tearing mode and the drift kink mode, with growth rates that are accurately described by existing linear theories. However, oblique modes are also linearly unstable, but with smaller growth rates than either the tearing or the drift-kink mode. The non-linear stage is first reached by the drift-kink mode, which alters the initial equilibrium and leads to a change in the growth rates of the tearing and oblique modes. In the nonlinear stage, the resulting changes in magnetic topology are incompatible with a pure tearing mode. The oblique mode is shown to introduce a helical structure into the magnetic field lines. C1 Politecn Torino, Ist Nazl Fis Mat, I-10129 Turin, Italy. Politecn Torino, Dipartimento Energet, I-10129 Turin, Italy. Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Lapenta, G (reprint author), Politecn Torino, Ist Nazl Fis Mat, Corso Duca Abruzzi 24, I-10129 Turin, Italy. OI Lapenta, Giovanni/0000-0002-3123-4024 NR 30 TC 30 Z9 30 U1 0 U2 1 PU COPERNICUS GESELLSCHAFT MBH PI GOTTINGEN PA BAHNHOFSALLEE 1E, GOTTINGEN, 37081, GERMANY SN 1023-5809 J9 NONLINEAR PROC GEOPH JI Nonlinear Process Geophys. PD SEP-DEC PY 2000 VL 7 IS 3-4 BP 151 EP 158 PG 8 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 348YG UT WOS:000089013600004 ER PT J AU Khaleel, MA Simonen, FA AF Khaleel, MA Simonen, FA TI A model for predicting vessel failure probabilities including the effects of service inspection and flaw sizing errors SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT ASME Pressure Vessels and Piping Conference (PVPC 97) CY JUL 27-31, 1997 CL ORLANDO, FLORIDA AB A numerical approach has been developed to predict the probability that a fabrication flaw in a reactor pressure vessel will extend by fatigue crack growth mechanisms and become a through-wall flaw. The fracture mechanics model treats the size of the flaw, the location of the flaw, and the parameters governing the fatigue crack growth rates as stochastic variables that are described by histograms that represent their statistical distributions. A latin hypercube approach forms the basis for efficient numerical calculations of vessel failure probabilities, in particular for those cases having very low probabilities that are not readily calculated by use of more conventional Monte Carlo simulations. A second aspect of the vessel failure model evaluates the benefits of in-service inspections at prescribed inspection time intervals and with prescribed nondestructive examination capabilities (probability of detection as a function of flaw size). A third aspect of the paper evaluates flaw sizing accuracy, and the impacts of flaw acceptance criteria. For representative values of flaw detection probability, flaw sizing errors, and flaw acceptance criteria, detection capability is the most limiting factor with regard to the ability of the in-service inspections to reduce leak probabilities. However, gross sizing errors or significant relaxations of current flaw acceptance standards could negate the benefits of outstanding probability of detection capabilities. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Pacific NW Lab, Virtual Prototyping & Engn Simulat Lab, Richland, WA 99352 USA. RP Khaleel, MA (reprint author), Pacific NW Lab, Virtual Prototyping & Engn Simulat Lab, POB 999,902 Battelle Blvd, Richland, WA 99352 USA. OI khaleel, mohammad/0000-0001-7048-0749 NR 21 TC 4 Z9 7 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD SEP PY 2000 VL 200 IS 3 BP 353 EP 369 DI 10.1016/S0029-5493(00)00244-2 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 336GX UT WOS:000088294500002 ER PT J AU Kondo, T Isobe, M Sasao, M Darrow, DS Toi, K Takechi, M Matsunaga, G Osakabe, M Yoshimura, Y Takahashi, C Nishimura, S Okamura, S Matsuoka, K AF Kondo, T Isobe, M Sasao, M Darrow, DS Toi, K Takechi, M Matsunaga, G Osakabe, M Yoshimura, Y Takahashi, C Nishimura, S Okamura, S Matsuoka, K CA CHS Grp TI Observation of MHD induced fast ion losses on the CHS heliotron/torsatron SO NUCLEAR FUSION LA English DT Article ID HELICAL SYSTEM HELIOTRON/TORSATRON; TOROIDAL ALFVEN EIGENMODES; FUSION TEST REACTOR; INTERNAL KINK; PRODUCTS; TOKAMAK; TFTR; MODES; PROBE AB MHD induced beam ion losses were observed on the CHS heliotron/torsatron with an energy and pitch angle resolved scintillator detector. Beam ions escaping into the probe were characterized using orbit calculation codes. It was found that two types of ions, namely 'passing boundary ions' and 'trapped ions'. were lost periodically during an m/n = 3/2 fishbone-like instability. There are thresholds in the mode amplitude fur the ejection of fast ions. Above this threshold, losses are enhanced together with an increase of the mode amplitude. The excitation of the fishbone-like instability and the enhancement of MHD induced losses strongly depend on the degree of accumulation of Learn ions in the plasma. Orbit calculations show that passing boundary ions, which have large pitch angle and nu(phi) close to zero (or close to title propagating velocity of the magnetic fluctuation) near the q = 3/2 surface, are ejected by the instability. C1 Grad Univ Adv Studies, Dept Fus Sci, Gifu, Japan. Natl Inst Fus Sci, Gifu, Japan. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Nagoya Univ, Dept Energy Engn Sci, Nagoya, Aichi, Japan. RP Kondo, T (reprint author), Grad Univ Adv Studies, Dept Fus Sci, Gifu, Japan. NR 32 TC 13 Z9 13 U1 0 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD SEP PY 2000 VL 40 IS 9 BP 1575 EP 1586 DI 10.1088/0029-5515/40/9/302 PG 12 WC Physics, Fluids & Plasmas SC Physics GA 353TA UT WOS:000089290500002 ER PT J AU Coomer, E Hartman, CW Morse, E Reisman, D AF Coomer, E Hartman, CW Morse, E Reisman, D TI An experimental and computational study of compact torus formation, decay and heating in the Berkeley Compact Torus Experiment SO NUCLEAR FUSION LA English DT Article ID SPHEX SPHEROMAK; RELAXATION; TRANSPORT AB A spheromak type compact torus (CT) plasma is investigated by studies of the gun type plasma formation mechanism and from the characteristics of the magnetic decay following the establishment uf a CT equilibrium in the flux conserver. Radiofrequency heating in the lower hybrid range (432 MHz) is used tu study the electron heat confinement using a 20 MW, 100 mu s power pulse. While electron temperatures up to 200 eV have been measured with RF heating, the impact on magnetic decay from the RF heating is relatively weak. A simple model based upon parallel electron heat transport along stochastic magnetic field lines gives a scaling lan for magnetic decay which fits the experimental data. Results: of two dimensional MHD code calculations are given which match many details of the experimentally observed formation physics. C1 Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Coomer, E (reprint author), Univ Calif Berkeley, Berkeley, CA 94720 USA. NR 30 TC 2 Z9 2 U1 0 U2 2 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD SEP PY 2000 VL 40 IS 9 BP 1669 EP 1681 DI 10.1088/0029-5515/40/9/310 PG 13 WC Physics, Fluids & Plasmas SC Physics GA 353TA UT WOS:000089290500010 ER PT J AU de Beer, A Hershcovitch, A Franklyn, CB van Straaten, S Guzek, J AF de Beer, A Hershcovitch, A Franklyn, CB van Straaten, S Guzek, J TI Performance of a plasma window for a high pressure differentially pumped deuterium gas target for mono-energetic fast neutron production - Preliminary results SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE fast neutrons; gas target; plasma window ID VACUUM-ATMOSPHERE INTERFACE; ION MATERIAL MODIFICATION; ARC PLASMA; BEAMS; LENS AB The reactions D(d,n)He-3 and T(d,n)He-4 are frequently used for production of the mono-energetic or quasi monoenergetic neutron beams but successful applications are often limited by the intensity of the generated neutron beams. The development of a suitable neutron source for such applications as studies of resonance phenomena, fast neutron radiography, selective fast neutron activation, explosives and contraband detection and others, depends on the output ion current of the accelerator and the design of the target system. A practical solution for a high pressure gas target was previously developed and successfully implemented at De Beers Diamond Research Laboratory in Johannesburg (Guzek et al., 1999), but it is limited to applications using low (<20%) duty cycle accelerators. The concept of a plasma window for the separation of a high pressure gas target region and accelerator vacuum, that was originally developed by Hershcovitch (1995) for electron welding applications, may be suitable for operation with continuous wave accelerators at high particle current output. Preliminary test results, which have been performed with various gases (argon, helium and deuterium), indicate that implementation of the plasma window into a gas target system, for the production of intense mono-energetic fast neutron beams will be achievable. (C) 2000 Elsevier Science B.V. All rights reserved. C1 De Beers, Diamond Res Lab, DebTech, ZA-2135 Southdale, South Africa. Brookhaven Natl Lab, Upton, NY 11973 USA. Atom Energy Corp S Africa Ltd, ZA-0001 Pretoria, South Africa. RP Guzek, J (reprint author), De Beers, Diamond Res Lab, DebTech, POB 82851, ZA-2135 Southdale, South Africa. NR 8 TC 12 Z9 12 U1 1 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 2000 VL 170 IS 1-2 BP 259 EP 265 DI 10.1016/S0168-583X(00)00175-0 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 353UB UT WOS:000089292900034 ER PT J AU Martinez-Guridi, G Samanta, P Chu, TL Yang, JW AF Martinez-Guridi, G Samanta, P Chu, TL Yang, JW TI Loca with consequential or delayed loop: Modeling of accident sequences and associated core damage frequency SO NUCLEAR TECHNOLOGY LA English DT Article DE loss-of-coolant accident; loss of off-site power; probabilistic risk assessment AB Following a loss-of-coolant accident (LOCA) in a nuclear power plant (NPP), the loss of electric-power generation, as might be precipitated by the unit tripping, may cause switchyard- and grid-instability with a subsequent loss-of-off-site power (LOOP). The LOOP usually is delayed by a few seconds or longer. This accident is called a LOCA with consequential LOOP, or a LOCA with delayed LOOP (abbreviated as LOCA/LOOP). NPPs are designed to cope with simultaneous LOCA and LOOP. The U.S. Nuclear Regulatory Commission (NRC) identified this issue as generic safety issue (GSI) 171, "Engineered Safety Feature Failure from a Loss-Of-Off-Site Power Subsequent to a Loss-of-Coolant Accident." NRC subsequently dropped GSI-171 and considers it resolved. We present the probabilistic risk analysis of the LOCA/LOOP scenario that was conducted as part of NRC's resolution of GSI-171. We analyze and quantify the core damage frequency (CDF) associated with this accident. Event/fault trees are developed covering the progression of the accident to core damage. We used engineering evaluations and judgments to estimate probabilities for the conditions identified in a LOCA/LOOP scenario and to obtain a bounding evaluation of the CDF. We show that the contribution of such an accident to CDF depends on electrical-load sequencing and shedding capabilities; plants with adequate capabilities incur a minimal additional contribution to risk. No single plant design is known to be vulnerable to all the conditions; only some of the conditions may apply to some plants. C1 Brookhaven Natl Lab, Dept Energy Sci & Technol, Upton, NY 11973 USA. RP Martinez-Guridi, G (reprint author), Brookhaven Natl Lab, Dept Energy Sci & Technol, POB 5000,Bldg 475C, Upton, NY 11973 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD SEP PY 2000 VL 131 IS 3 BP 297 EP 318 PG 22 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 345PV UT WOS:000088825100002 ER PT J AU Forsberg, CW AF Forsberg, CW TI Effect of depleted-uranium dioxide particulate fill on spent-nuclear-fuel waste packages SO NUCLEAR TECHNOLOGY LA English DT Article DE repository; spent nuclear fuel; depleted uranium ID CRITICAL CONFIGURATIONS; GEOLOGIC REPOSITORIES; NEUTRONIC ANALYSIS; YUCCA MOUNTAIN; URANINITE; SYSTEM; OXIDES; FLOW AB The use of depleted uranium dioxide (DUO2) particulates as fill material for repository waste packages (WPs) containing light-water reactor (LWR) spent nuclear fuel (SNF) was investigated A repository WP would be loaded with SNF, and small DUO2 particulates (0.5 to 1.0 mm) would be added to fill the void space inside the WP-including the coolant channels inside SNF assemblies. The DUO2 fill slows release of radionuclides from the SNF by (a) creating a local chemically reducing environment that slows degradation of the SNF UO2 and (b) reducing groundwater flow through the WP. The depleted uranium (DU) fill minimizes the potential for long-term criticality in the repository by isotopic dilution of U-233 and U-235. The potential for criticality is primarily determined by U-235 (a) originally in the SNF and (6) from decay of Pu-239. The use of DU consumes excess DU from the production of enriched uranium. The mechanisms for improvements in repository performance with DUO2 fill are defined, but additional work is required to fully quantify the benefits and costs of such an approach. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Forsberg, CW (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 59 TC 8 Z9 8 U1 1 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD SEP PY 2000 VL 131 IS 3 BP 337 EP 353 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 345PV UT WOS:000088825100005 ER PT J AU Hacke, UG Sperry, JS Ewers, BE Ellsworth, DS Schafer, KVR Oren, R AF Hacke, UG Sperry, JS Ewers, BE Ellsworth, DS Schafer, KVR Oren, R TI Influence of soil porosity on water use in Pinus taeda SO OECOLOGIA LA English DT Article DE Pinus taeda; xylem cavitation; soil water transport; root-shoot relations; stomatal regulation ID STOMATAL CONDUCTANCE; XYLEM CAVITATION; LOBLOLLY-PINE; HYDRAULIC CONDUCTANCE; BETULA-OCCIDENTALIS; HYMENOCLEA-SALSOLA; DOUGLAS-FIR; VULNERABILITY; TRANSPIRATION; EMBOLISM AB We analyzed the hydraulic constraints imposed on water uptake from soils of different porosities in loblolly pine (Pinus taeda L.) by comparing genetically related and even-aged plantations growing in loam versus sand soil. Water use was evaluated relative to the maximum transpiration rate (E-crit) allowed by the soil-leaf continuum. We expected that trees on both soils would approach E-crit during drought. Trees in sand, however, should face greater drought limitation because of steeply declining hydraulic conductivity in sand at high soil water potential (Psi(S)). Transport considerations suggest that trees in sand should have higher root to leaf area ratios (A(R):A(L)): less negative leaf xylem pressure (Psi(L)), and be more vulnerable to xylem cavitation than trees in loam. The A(R):A(L) was greater in sand versus loam (9.8 vs 1.7, respectively). This adjustment maintained about 86% of the water extraction potential for both soils. Trees in sand were more deeply rooted (>1.9 m) than in loam (95% of roots <0.2 m), allowing them to shift water uptake to deeper layers during drought and avoid hydraulic failure. Midday Psi(L) was constant for days of high evaporative demand, but was less negative in sand (-1.6 MPa) versus loam (-2.1 MPa). Xylem was more vulnerable to cavitation in sand versus loam trees. Roots in both soils were more vulnerable than stems, and experienced the greatest predicted loss of conductivity during drought. Trees on both soils approached E-crit during drought, but at much higher Psi(S) in sand (<-0.4 MPa) than in loam (<-1.0 MPa). Results suggest considerable phenotypic plasticity in water use traits for P. taeda which are adaptive to differences in soil porosity. C1 Univ Utah, Dept Biol, Salt Lake City, UT 84112 USA. Univ Wisconsin, Dept Forest Ecol & Management, Madison, WI 53706 USA. Duke Univ, Nicholas Sch Environm, Durham, NC 27708 USA. Brookhaven Natl Lab, Div Environm Biol, Upton, NY 11973 USA. RP Hacke, UG (reprint author), Univ Utah, Dept Biol, Salt Lake City, UT 84112 USA. RI Ewers, Brent/A-9696-2008; Hacke, Uwe/M-7719-2015; OI Hacke, Uwe/0000-0001-5983-3582; Ellsworth, David/0000-0002-9699-2272 NR 41 TC 204 Z9 213 U1 6 U2 57 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0029-8549 J9 OECOLOGIA JI Oecologia PD SEP PY 2000 VL 124 IS 4 BP 495 EP 505 DI 10.1007/PL00008875 PG 11 WC Ecology SC Environmental Sciences & Ecology GA 357PH UT WOS:000089509700004 PM 28308388 ER PT J AU Lin, SY Chow, E Johnson, SG Joannopoulos, JD AF Lin, SY Chow, E Johnson, SG Joannopoulos, JD TI Demonstration of highly efficient waveguiding in a photonic crystal slab at the 1.5-mu m wavelength SO OPTICS LETTERS LA English DT Article ID WAVE-GUIDE BENDS; BANDGAP MATERIALS AB Highly efficient transmission of 1.5-mu m light in a two-dimensional (2D) photonic crystal slab waveguide is experimentally demonstrated. Light waves are shown to be guided along a triple-line defect formed within a 2D crystal and vertically by a strong index-guiding mechanism. At certain wavelength ranges, complete transmission is observed, suggesting lossless guiding along this photonic one-dimensional conduction channel. (C) 2000 Optical Society of America OCIS code: 230.7370. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. RP Lin, SY (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 120 Z9 121 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD SEP 1 PY 2000 VL 25 IS 17 BP 1297 EP 1299 DI 10.1364/OL.25.001297 PG 3 WC Optics SC Optics GA 349KV UT WOS:000089045000025 PM 18066198 ER PT J AU Peralta, P Ramamurty, U Suresh, S Campbell, GH King, WE Mitchell, TE AF Peralta, P Ramamurty, U Suresh, S Campbell, GH King, WE Mitchell, TE TI Crystallographic effects on the fatigue fracture of copper-sapphire interfaces SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID CRACK-PROPAGATION; ALUMINA; RESISTANCE; BICRYSTALS; DEPENDENCE; MECHANISM; CRYSTALS; GROWTH AB Interfacial fatigue cracks were propagated in copper-sapphire bicrystals with the boundary perpendicular to the load axis and (110)(Cu)parallel to(10(1) over bar 0)(Al2O3) - [001](Cu)parallel to[0001](Al2O3) to study the effect of crystallography in the fracture process. Cylindrical samples with a circumferential notch were loaded in compression-compression and compact tension specimens in tension-tension, Three interfacial cracks in the cylindrical sample nucleated simultaneously at sites corresponding to the maximum slip length, under local single slip conditions, for three of the four slip vectors expected for the [110] loading axis in the copper crystal. These cracks arrested with continued cycling, while two new cracks nucleated at 0 degrees and 180 degrees from [<1(1)over bar>0](Cu), which also self-arrested. Then another crack started at 90 degrees from [<1(1)over bar>0](Cu) and grew with an inclined front. Striations could be observed on the copper fracture surfaces; however, they did not coincide macroscopically with traces of {111} slip planes. Large areas were also relatively free of features. Elastic analysis of the anisotropic near-tip stress fields for the interfacial crack revealed that the dominant crack growth direction had the highest energy release rate, whereas the second crack direction had the minimum mode II mix. A model to account for the noncrystallographic striations is proposed. C1 Arizona State Univ, Dept Mech & Aerosp Engn, Tempe, AZ 85287 USA. Nanyang Technol Univ, Sch Mech & Prod Engn, Singapore 639798, Singapore. MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Peralta, P (reprint author), Arizona State Univ, Dept Mech & Aerosp Engn, POB 876106, Tempe, AZ 85287 USA. EM pperalta@asu.edu RI Campbell, Geoffrey/F-7681-2010; Ramamurty, Upadrasta/E-5623-2011 NR 25 TC 13 Z9 13 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD SEP PY 2000 VL 80 IS 9 BP 2109 EP 2129 PG 21 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 354JM UT WOS:000089327300009 ER PT J AU Stach, EA Hull, R Tromp, RM Ross, FM Reuter, MC Bean, JC AF Stach, EA Hull, R Tromp, RM Ross, FM Reuter, MC Bean, JC TI In-situ transmission electron microscopy studies of the interaction between dislocations in strained SiGe/Si(001) heterostructures SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID MISFIT DISLOCATION; EPITAXIAL LAYER; GEXSI1-X/SI(100) HETEROSTRUCTURES; THREADING DISLOCATION; SURFACE-MORPHOLOGY; MESOSCOPIC SCALE; POINT-DEFECTS; GLIDE PLANES; THIN-FILMS; RELAXATION AB The rate of misfit strain relaxation in semiconductor heterostructures is controlled by the kinetics of misfit dislocation nucleation, propagation and interaction. Although there have been a number of detailed theoretical studies of the dislocation-dislocation interaction process in these systems, there exist limited experimental data regarding the regime of epilayer thickness and composition where these interactions affect strain relaxation. Because of its high spatial and temporal resolution, in-situ transmission electron microscopy is an ideal experimental tool with which to observe dislocation interactions. In this work, the unique capabilities of an ultrahigh vacuum transmission electron microscope have been exploited to permit direct, real-time observation of dislocation interactions. This microscope is equipped with in-situ chemical vapour deposition capabilities which allow imaging of dislocation motion during both growth and annealing of SiGe/Si(001) heterostructures. This has permitted efficient determination of the regime of epilayer thickness and composition where dislocation interactions stop the forward motion of the threading dislocation segment. At the lowest thicknesses and compositions, all dislocation interactions cause the threading segment to become blocked. Above a certain level of thickness and composition dislocation motion is halted only when the two dislocations have parallel Burgers vectors. This is due to a particular reaction between the dislocations which occurs at their intersection. Quantitative analysis of the dynamic motion of threading dislocations while in the presence of the stress field of the interfacial segment allows extraction of the magnitude of the long range interaction stresses. It is seen that the magnitude of the interaction stresses increases as the net excess stress in the epilayer increases, and that the interaction stresses are much greater when the Burgers vectors are parallel. Finally, additional experiments have indicated that dislocations that become blocked during annealing form relatively stable configurations. Following the blocking event a force greater than that associated with the long range interaction between dislocations is required to release the dislocations from their blocked configuration. This is ill contrast to theoretical models, which predict that the long range interaction force alone controls the release of dislocations. These experiments represent the first systematic study of dislocation interactions in strained heterostructures and permit improved predictive models of the kinetics of strain relaxation in these systems. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Univ Virginia, Sch Engn & Appl Sci, Dept Mat Sci & Engn, Charlottesville, VA 22903 USA. Univ Virginia, Sch Engn & Appl Sci, Dept Elect Engn, Charlottesville, VA 22903 USA. IBM Corp, Div Res, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA. RP Stach, EA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. EM eastach@lbl.gov RI Stach, Eric/D-8545-2011 OI Stach, Eric/0000-0002-3366-2153 NR 51 TC 19 Z9 19 U1 3 U2 22 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD SEP PY 2000 VL 80 IS 9 BP 2159 EP 2200 PG 42 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 354JM UT WOS:000089327300011 ER PT J AU Sachenko, P Schneibel, JH Swadener, JG Zhang, W AF Sachenko, P Schneibel, JH Swadener, JG Zhang, W TI Experimental and simulated grain boundary groove profiles in tungsten SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article AB Grain-boundary grooving has been studied on polished surfaces of polycrystalline tungsten annealed at 1350 degrees C. Atomic force microscopy images were taken in the same area for each groove after different annealing times. Secondary oscillations next to the main groove maxima (predicted for grooving by surface diffusion) were observed, to our knowledge for the first time. The agreement between experimental and calculated groove profiles (using the surface diffusion model of Mullins (1957, J. appl. Phys., 28, 333)) improved when grain-boundary fluxes were introduced. C1 Oakland Univ, Dept Mech Engn, Rochester, MI 48309 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Oakland Univ, Dept Math & Stat, Rochester, MI 48309 USA. RP Sachenko, P (reprint author), Oakland Univ, Dept Mech Engn, Rochester, MI 48309 USA. NR 6 TC 15 Z9 15 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD SEP PY 2000 VL 80 IS 9 BP 627 EP 631 DI 10.1080/09500830050134345 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 350KQ UT WOS:000089100200005 ER PT J AU Mahan, AH Beyer, W Williamson, DL Yang, J Guha, S AF Mahan, AH Beyer, W Williamson, DL Yang, J Guha, S TI An explanation for the low-temperature H evolution peak in hydrogenated amorphous silicon films deposited 'on the edge of crystallinity' SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article AB The puzzling existence of a sharp low-temperature (T = 400 degrees C) H evolution peak in compact hydrogenated amorphous silicon (a-Si:H) films deposited 'on the edge of crystallinity' is examined. From infrared absorption and X-ray diffraction (XRD) measurements, we show that none of the standard methods used to explain the existence of this peak in a-Si:H materials is applicable to the present films. From the Si-H wag-mode peak frequency, we postulate the existence of very small Si crystallites contained within the amorphous matrix. While the crystallite Volume fraction is too small to be detected by XRD in the as-grown films, crystallization is observed for this material at anneal temperatures as low as 500 degrees C. It is proposed that these crystallites catalyse the crystallization of the remainder of the amorphous matrix upon moderate annealing, enabling H surface desorption and Hz out-diffusion to the sample surface along newly formed grain boundaries at low anneal temperatures. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Forschungszentrum Julich, Julich, Germany. Colorado Sch Mines, Golden, CO 80401 USA. United Solar Syst Corp, Troy, MI 48084 USA. RP Mahan, AH (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM harv_mahan@nrel.gov NR 14 TC 21 Z9 21 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD SEP PY 2000 VL 80 IS 9 BP 647 EP 652 DI 10.1080/09500830050134372 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 350KQ UT WOS:000089100200008 ER PT J AU Shumway, J Fonseca, LRC Leburton, JP Martin, RM Ceperley, DM AF Shumway, J Fonseca, LRC Leburton, JP Martin, RM Ceperley, DM TI Electronic structure of self-assembled quantum dots: comparison between density functional theory and diffusion quantum Monte Carlo SO PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES LA English DT Article DE quantum dots; quantum Monte Carlo; density functional theory ID MAGNETIC-FIELDS; SPECTROSCOPY; COULOMB; GAAS AB We have calculated the exchange, correlation, and total electronic energy of a realistic InAs self-assembled quantum dot embedded in a GaAs matrix as a function of the number of electrons in the dot. The many-body interactions have been treated using the local spin density approximation (LSDA) to density functional theory (DFT) and diffusion quantum Monte Carlo (DMC), so that we may quantify the error introduced by LSDA. The comparison shows that the LSDA errors are about 1-2 meV per electron for the system considered. These errors are small enough to justify the use of LSDA calculations to test models of self-assembled dots against current experimental measurements. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Illinois, Beckman Inst Adv Sci & Technol, Urbana, IL 61801 USA. Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA. RP NREL, 1617 Cole Blvd, Golden, CO 80401 USA. EM jshumway@nrel.gov RI Ceperley, David/A-6858-2008 NR 29 TC 26 Z9 26 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1386-9477 EI 1873-1759 J9 PHYSICA E JI Physica E PD SEP PY 2000 VL 8 IS 3 BP 260 EP 268 DI 10.1016/S1386-9477(00)00141-7 PG 9 WC Nanoscience & Nanotechnology; Physics, Condensed Matter SC Science & Technology - Other Topics; Physics GA 362FE UT WOS:000089767300009 ER PT J AU Neukirch, U Bolton, SR Sham, LJ Chemla, DS AF Neukirch, U Bolton, SR Sham, LJ Chemla, DS TI Effects of electronic fourth-order correlations on the pump-probe response of semiconductors SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 6th International Workshop on Nonlinear Optics and Excitation Kinetics in Semiconductors (NOEKS 2000) CY APR 10-13, 2000 CL MARBURG, GERMANY SP Deutsch Forsch GmbH ID TRANSIENT OSCILLATIONS; FEMTOSECOND; EXCITONS AB The pump-and-probe response of a ZnSe quantum well is investigated. In this particular sample the binding energy far exceeds both the exciton damping and the inhomogeneous broadening. A comparison between experimental data and model calculations shows that with co-circularly polarized beams the nonlinear mean-field contributions dominate those induced by four-particle correlations. In contrast, only the four-particle correlations contribute to the signal in counter-circular configuration. For this configuration, the exciton-biexciton interaction dominates the response for resonant excitation of the exciton. The occurrence of exciton-biexciton transitions leads to a renormalization of the period of coherent oscillations at negative pulse delay. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Williams Coll, Dept Phys, Williamstown, MA 01267 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Neukirch, U (reprint author), Univ Bremen, Inst Festkorperphys, POB 330 440, D-28334 Bremen, Germany. OI Sham, Lu/0000-0001-5718-2077 NR 12 TC 2 Z9 2 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD SEP PY 2000 VL 221 IS 1 BP 511 EP 515 DI 10.1002/1521-3951(200009)221:1<511::AID-PSSB511>3.0.CO;2-9 PG 5 WC Physics, Condensed Matter SC Physics GA 362PZ UT WOS:000089788000091 ER PT J AU Schafer, W Lovenich, R Fromer, N Chemla, DS AF Schafer, W Lovenich, R Fromer, N Chemla, DS TI Formation and decay of coherent four-particle correlations in semiconductors: A Green's function theory SO PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS LA English DT Article; Proceedings Paper CT 6th International Workshop on Nonlinear Optics and Excitation Kinetics in Semiconductors (NOEKS 2000) CY APR 10-13, 2000 CL MARBURG, GERMANY SP Deutsch Forsch GmbH ID COULOMB SCATTERING; GAAS AB Recent conceptual advances in the theory of physics of highly excited semiconductors are based on two formalisms, the real-time non-equilibrium Green's function techniques and the coherently controlled truncation of the many-particle problems. These approaches apply to completely different but complementary experimental conditions. We present a novel many-particle theory, which contains both of these methods as limiting cases. As a first example of its application, we investigate four-particle correlations in a strong magnetic field including dephasing resulting from the growth of incoherent one-particle distribution functions. Our results are the first numerical rigorous solutions of the four-particle problem in a semiconductor. They are in excellent agreement with experimental data. C1 Forschungszentrum Julich, John von Neumann Inst Comp, D-52425 Julich, Germany. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Schafer, W (reprint author), Forschungszentrum Julich, John von Neumann Inst Comp, Postfach 1913, D-52425 Julich, Germany. NR 20 TC 5 Z9 5 U1 1 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Solid State Phys. PD SEP PY 2000 VL 221 IS 1 BP 195 EP 204 DI 10.1002/1521-3951(200009)221:1<195::AID-PSSB195>3.0.CO;2-E PG 10 WC Physics, Condensed Matter SC Physics GA 362PZ UT WOS:000089788000034 ER PT J AU McCurdy, CW Rescigno, TN AF McCurdy, CW Rescigno, TN TI Practical calculations of quantum breakup cross sections SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON-IMPACT IONIZATION; ASYMPTOTIC FORM; E,2E; AUTOIONIZATION; VICINITY; STATES AB The Schrodinger equation is solved numerically using the method of exterior complex scaling for several models of the breakup of an atom by electron impact. Using the accurate wave functions thereby obtained for these model problems, several well-known integral expressions for quantum-mechanical breakup amplitudes are tested. It is shown that some formally correct integral expressions for the breakup amplitudes can yield numerically unstable or poorly convergent results. Calculations are presented for a case with simple exponential potentials and a case in which a metastable state of the target, analogous to an autoionizing state, can decay into the breakup channel. For cases involving only short-range (non-Coulomb) interactions, alternative expressions can be found that are stable in calculations of practical scale. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Phys Directorate, Livermore, CA 94551 USA. Univ Calif Davis, Dept Appl Sci, Livermore, CA 94551 USA. RP McCurdy, CW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 25 TC 26 Z9 27 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 2000 VL 62 IS 3 BP art. no. EP 032712 DI 10.1103/PhysRevA.62.032712 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 353CD UT WOS:000089255400051 ER PT J AU Moszkowski, S Fleck, S Krikeb, A Theussl, L Richard, JM Varga, K AF Moszkowski, S Fleck, S Krikeb, A Theussl, L Richard, JM Varga, K TI Binding three or four bosons without bound subsystems SO PHYSICAL REVIEW A LA English DT Article ID VARIATIONAL METHOD; STATE PROPERTIES; SYSTEMS; POTENTIALS; MOLECULES AB We estimate the ratio R=g(3)/g(2) Of the critical coupling constants g(2) and g(3) that are required to achieve binding of two or three bosons, respectively, with a short-range interaction, and examine how this ratio depends on the shape of the potential. Simple monotonous potentials give R similar or equal to 0.8. A wide repulsive core pushes this ratio close to R=1. On the other hand, for an attractive well protected by an external repulsive barrier, the ratio approaches the rigorous lower bound R = 2/3. We also present results for N = 4 bosons, sketch the extension to N>4, and discuss various consequences. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ Lyon 1, Inst Phys Nucl Lyon, CNRS, IN2P3, F-69622 Villeurbanne, France. Univ Grenoble 1, Inst Sci Nucl, CNRS, IN2P3, F-38026 Grenoble, France. Argonne Natl Lab, Argonne, IL 60439 USA. RP Moszkowski, S (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RI Varga, Kalman/A-7102-2013 NR 31 TC 18 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 SEP PY 2000 VL 62 IS 3 BP art. no. EP 032504 DI 10.1103/PhysRevA.62.032504 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 353CD UT WOS:000089255400031 ER PT J AU Kukk, E Bozek, JD Berrah, N AF Kukk, E Bozek, JD Berrah, N TI Photoexcitation and Auger decay of the Renner-Teller split C 1s(-1) pi(*)(u) state in CO2 SO PHYSICAL REVIEW A LA English DT Article ID CARBON-MONOXIDE; RESOLUTION; SPECTRUM AB The broad (approximate to 700 meV) C 1s --> pi(u)* resonance in the absorption spectrum of CO2 has been decomposed into contributions from two Renner-Teller split con-excited states with bent and linear equilibrium geometries using resonant Auger spectroscopy. The C 1s(-1) pi* excited state was found to decay primarily via participator Auger transitions to the A (2)Pi(u) state of CO2+. Analysis of the vibrational structure in the high-resolution Auger spectra, measured at several photon energies across the broad C 1s-->pi(u)* resonance, was accomplished using calculated Franck-Condon factors for the electronic excitation and de-excitation processes. Estimations of the geometries of the Renner-Teller split core-excited states were obtained from a comparison of the calculations with the resonant Auger spectra. Transitions to the bent core-excited state were found to contribute to the absorption profile exclusively at the photon energies below the maximum of the C 1s --> pi(u)* resonance, whereas the linear con-excited state becomes accessible at higher photon energies. The symmetric stretch vibrational progression of the linear core-excited state was identified and assigned. The minimum of the potential energy surface of the C 1s(-1) pi* core-excited state at its linear configuration was estimated to be 290.4 eV above the ground vibrational level of the ground electronic state of CO2. C1 Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. RI Bozek, John/E-4689-2010; Bozek, John/E-9260-2010 OI Bozek, John/0000-0001-7486-7238 NR 17 TC 31 Z9 31 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 2000 VL 62 IS 3 AR 032708 DI 10.1103/PhysRevA.62.032708 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 353CD UT WOS:000089255400047 ER PT J AU Rescigno, TN McCurdy, CW AF Rescigno, TN McCurdy, CW TI Numerical grid methods for quantum-mechanical scattering problems SO PHYSICAL REVIEW A LA English DT Article ID COMPLEX; IONIZATION AB We show how the finite-element method can be implemented using a discrete variable representation to provide an efficient means for directly solving the time-independent Schrodinger equation on a multidimensional numerical grid. For collision problems, an exterior complex scaling transformation obviates the need for explicit imposition of asymptotic boundary conditions, making the method particularly useful for studying three-body breakup. The method is illustrated by studying an analytically solvable two-dimensional (2D) breakup problem as well as a 2D model problem with exponential potentials. C1 Univ Calif Lawrence Livermore Natl Lab, Phys Directorate, Livermore, CA 94551 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Comp Sci Directorate, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Appl Sci, Livermore, CA 94551 USA. RP Rescigno, TN (reprint author), Univ Calif Lawrence Livermore Natl Lab, Phys Directorate, Livermore, CA 94551 USA. NR 18 TC 179 Z9 179 U1 3 U2 21 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 2000 VL 62 IS 3 AR 032706 DI 10.1103/PhysRevA.62.032706 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 353CD UT WOS:000089255400045 ER PT J AU Tseng, CH Somaroo, S Sharf, Y Knill, E Laflamme, R Havel, TF Cory, DG AF Tseng, CH Somaroo, S Sharf, Y Knill, E Laflamme, R Havel, TF Cory, DG TI Quantum simulation with natural decoherence SO PHYSICAL REVIEW A LA English DT Article ID ERROR-CORRECTING CODES; MAGNETIC-RESONANCE; COMPUTATION; COMPUTER; SYSTEMS; UNIVERSAL; RELAXATION; GATES; STATE AB A quantum system may be efficiently simulated by a quantum information processor as suggested by Feynman and developed by Lloyd, Wiesner, and Zalka. Within the limits of the experimental implementation, simulation permits the design and control of the kinematic and dynamic parameters of a quantum system. Extension to the inclusion of the effects of decoherence, if approached from a full quantum-mechanical treatment of the system and the environment, or from a semiclassical fluctuating field treatment (Langevin), requires the difficult access to dynamics on the time scale of the environment correlation time. Alternatively a quantum-statistical approach may be taken which exploits the natural decoherence of the experimental system, and requires a more modest control of the dynamics. This is illustrated for quantum simulations of a four-level quantum system by a two-spin NMR ensemble quantum information processor. C1 MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. Univ Calif Los Alamos Natl Lab, Div Theoret Phys, Los Alamos, NM 87455 USA. Harvard Univ, Sch Med, BCMP, Boston, MA 02115 USA. RP Tseng, CH (reprint author), MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. NR 42 TC 13 Z9 13 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 SEP PY 2000 VL 62 IS 3 AR 032309 DI 10.1103/PhysRevA.62.032309 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 353CD UT WOS:000089255400023 ER PT J AU Lookman, T Saxena, A Dimitrov, DA Bishop, AR Albers, RC AF Lookman, T Saxena, A Dimitrov, DA Bishop, AR Albers, RC TI Signatures of long-range elastic interaction in textured materials SO PHYSICAL REVIEW B LA English DT Article ID NI-AL ALLOYS; TWEED MICROSTRUCTURES; NEUTRON-SCATTERING; PHASE-TRANSITIONS; TRANSFORMATION; BEHAVIOR AB We show that specific signatures in the pair distribution function and x-ray and neutron-scattering structure factors in a variety of functional elastic materials, previously ascribed to local structural distortions, could instead he due to an underlying anisotropic, long-range elastic field. We illustrate this conclusion on simple textures, e.g., twins, tweed, using relaxational computer simulations, pair distribution function analysis, and structure factors in two dimensions. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. NR 26 TC 1 Z9 1 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 2000 VL 62 IS 9 BP 5265 EP 5269 DI 10.1103/PhysRevB.62.5265 PG 5 WC Physics, Condensed Matter SC Physics GA 352JZ UT WOS:000089212900001 ER PT J AU Guo, CL Taylor, AJ AF Guo, CL Taylor, AJ TI Ultrafast electronic disorder in heat-induced structural deformations and phase transitions in metals SO PHYSICAL REVIEW B LA English DT Article ID TIME-RESOLVED REFLECTIVITY; FEMTOSECOND LASER-PULSES; NONEQUILIBRIUM ELECTRON; OPTICAL-PROPERTIES; GAAS; GOLD; THERMALIZATION; COPPER; ABSORPTION; EXCITATION AB Heat-induced structural deformations and phase transitions of gold and silver are studied using 1.55-eV, 120-fs ultrashort laser pulses. The dynamics of the heating process is monitored by measuring the time evolution of the dielectric constants following optical excitation. Intensity-dependent dielectric constants in silver and old show similarities with the photon-energy-dependent dielectric constants, which is shown to indirectly map out the degree of hear-induced electronic disorder in these noble metals. This observation strongly suggests that the heat-induced structural deformations and phase transitions in metals are tied to the electronic disorder and band-structure collapse. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Guo, CL (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Condensed Matter & Thermal Phys Grp, Mail Stop K764, Los Alamos, NM 87545 USA. NR 35 TC 15 Z9 15 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 SEP 1 PY 2000 VL 62 IS 9 BP 5382 EP 5386 DI 10.1103/PhysRevB.62.5382 PG 5 WC Physics, Condensed Matter SC Physics GA 352JZ UT WOS:000089212900032 ER PT J AU Bastea, S Ree, FH AF Bastea, S Ree, FH TI Consistent anisotropic repulsions for simple molecules SO PHYSICAL REVIEW B LA English DT Article ID HIGH-PRESSURE; LIQUID-NITROGEN; SOLID NITROGEN; GPA; THERMODYNAMICS; TEMPERATURE; POTENTIALS; DYNAMICS; SYSTEMS; FLUIDS AB Wr extract atom-atom potentials from the effective spherical potentials that successfully model Hugoniot experiments on molecular fluids, e.g., O-2 and N-2. In the case of O-2 the resulting potentials compare very well with the atom-atom potentials used in studies of solid-state properties, while for N-2 they are considerably softer at short distances. Ground-state (T = 0 K) and room-temperature calculations performed with the N-N potential resolve the previous discrepancy between experimental and theoretical results. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bastea, S (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. EM bastea2@llnl.gov; ree1@llnl.gov NR 38 TC 3 Z9 3 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 2000 VL 62 IS 9 BP 5478 EP 5481 DI 10.1103/PhysRevB.62.5478 PG 4 WC Physics, Condensed Matter SC Physics GA 352JZ UT WOS:000089212900043 ER PT J AU Tsunoda, Y Hirano, M Crow, ML Robertson, JL AF Tsunoda, Y Hirano, M Crow, ML Robertson, JL TI Atomic shore-range order and magnetism in Pt1-xCrx alloys SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-WAVE CLUSTERS; SPIN-GLASS ALLOYS AB Atomic short-range order and magnetism in Pt1-xCrx alloys with x = 0.07, 0.10, 0.13, and 0.16 were studied by means of neutron scattering and susceptibility measurements. The tatter showed a spin-glass-type anomaly at low temperature for x=0.13 and 0.16, but a monotonic increase towards the lowest temperature for x = 0.07 and 0.10. In neutron scattering, broad satellite peaks with asymmetric intensities were observed for all specimens along the [1 0 0] direction, even at room temperature. These peaks are well explained as a concentration wave of constituent atoms accompanied with a periodic lattice deformation. Magnetic diffuse scattering was observed for the specimens with x=0.13 and 0.16. The origin of the spin-glass-like behavior in these alloys is ascribed to the dynamics and freezing of spin-density-wave cluster fluctuations, similar to the case of CuMn spin-glass alloys. A breakdown of the Kondo singlet state was studied for an x = 0.10 nonmagnetic alloy using neutron scattering under a magnetic field of 6 T. C1 Waseda Univ, Sch Sci & Engn, Dept Appl Phys, Shinjuku Ku, Tokyo 1698555, Japan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Tsunoda, Y (reprint author), Waseda Univ, Sch Sci & Engn, Dept Appl Phys, Shinjuku Ku, 3-4-1 Okubo, Tokyo 1698555, Japan. NR 10 TC 2 Z9 2 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 2000 VL 62 IS 9 BP 5570 EP 5575 DI 10.1103/PhysRevB.62.5570 PG 6 WC Physics, Condensed Matter SC Physics GA 352JZ UT WOS:000089212900058 ER PT J AU Kucherenko, Y Sinkovic, B Shekel, E Rennert, P Hulbert, S AF Kucherenko, Y Sinkovic, B Shekel, E Rennert, P Hulbert, S TI Spin-resolved Fe L3M2,3M2,3 and L3M2,3V Auger transitions on and off resonance by excitation with linearly polarized photons SO PHYSICAL REVIEW B LA English DT Article ID RAY-PHOTOELECTRON-SPECTROSCOPY; CORE-LEVEL PHOTOEMISSION; ELECTRON-DIFFRACTION; FE(001); SPECTRA; LIGHT AB Spin polarized Fe L3M2,3M2,3 and L3M2,3V Auger-electron spectra were measured and calculated using on-resonance excitation energies of linearly polarized photons (at the 2p(3/2) threshold) as well as in the off resonance region. Both the intensity distribution and the spin polarization in the experimentally obtained Auger spectra are explained by means of the theoretical model taking into account spin-orbit splitting of core levels and exchange interaction of the core states with the polarized valence band. Different contributions to the Auger spin polarization of both CCC (Fe L3M2,3M2,3) and CCV (Fe L3M2,3V) Auger spectra are discussed. Auger electron spin polarization is positive by transitions to the singlet final two-hole states and is increased with increasing core state-valence state exchange interaction, whereas for the triplet final states the opposite behavior is found. C1 Ukrainian Acad Sci, Inst Met Phys, UA-252142 Kiev, Ukraine. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. NYU, Dept Phys, New York, NY 10003 USA. Univ Halle Wittenberg, Dept Phys, D-06099 Halle, Germany. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Kucherenko, Y (reprint author), Ukrainian Acad Sci, Inst Met Phys, UA-252142 Kiev, Ukraine. EM rennert@physik.uni-halle.de NR 37 TC 12 Z9 12 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 2000 VL 62 IS 9 BP 5733 EP 5741 DI 10.1103/PhysRevB.62.5733 PG 9 WC Physics, Condensed Matter SC Physics GA 352JZ UT WOS:000089212900077 ER PT J AU Westfahl, H Morr, DK AF Westfahl, H Morr, DK TI Theory for the spin susceptibility in the pseudogap regime of the underdoped cuprates: Effect of phase fluctuations SO PHYSICAL REVIEW B LA English DT Article ID T-C SUPERCONDUCTORS; BI2SR2CACU2O8+DELTA; NMR; YBA2CU3O7; SYSTEM; STATE; GAP AB We present a theory for the temperature and frequency dependence of the spin susceptibility chi" in the presence of superconducting phase fluctuations. Our scenario, which is based on the spin-fermion model provides an explanation for the presence of a resonance peak above T-1 as observed by inelastic neutron scattering experiments in the underdoped cuprates. Within the same framework we show that the (CU)-C-63 spin-lattice relaxation time T-1 directly probes the strength of phase fluctuations. A comparison of our theoretical results with the experimental NMR data on underdoped Bi-2212 suggests that phase fluctuations exist only in limited temperature range above T-c in agreement with recent experiments by Corson et al. C1 Univ Illinois, Loomis Lab Phys, Urbana, IL 61801 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Westfahl, H (reprint author), Univ Illinois, Loomis Lab Phys, 1110 W Green St, Urbana, IL 61801 USA. NR 26 TC 4 Z9 4 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 SEP 1 PY 2000 VL 62 IS 9 BP 5891 EP 5895 DI 10.1103/PhysRevB.62.5891 PG 5 WC Physics, Condensed Matter SC Physics GA 352JZ UT WOS:000089212900100 ER PT J AU Helm, C Preis, C Walter, C Keller, J AF Helm, C Preis, C Walter, C Keller, J TI Theory for the coupling between longitudinal phonons and intrinsic Josephson oscillations in layered superconductors SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; INFRARED-ACTIVE MODES; SUBGAP STRUCTURES; CUPRATE SUPERCONDUCTORS; LATTICE-DYNAMICS; SINGLE-CRYSTALS; JUNCTIONS; BI2SR2CACU2O8+DELTA; TL2BA2CA2CU3O10+DELTA; SPECTROSCOPY AB A microscopic theory for the coupling of intrinsic Josephson oscillations in layered superconductors with longitudinal c-axis phonons is developed, it is shown that the influence of lattice vibrations on the c-axis transport can be fully described by introducing an effective longitudinal dielectric function epsilon(ph)(L)(w). Resonances in the I-V characteristic appear at van Hove singularities of both acoustical and optical longitudinal phonon branches. This provides a natural explanation of the recently discovered subgap structures in the I-V characteristic of highly anisotropic cuprate superconductors. The effect of the phonon dispersion on the damping of these resonances and the coupling of Josephson oscillations in different resistive junctions due to phonons are discussed in detail. C1 Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. Univ Calif Los Alamos Natl Lab, Div T11, Los Alamos, NM 87545 USA. RP Helm, C (reprint author), Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. NR 33 TC 17 Z9 17 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 2000 VL 62 IS 9 BP 6002 EP 6014 DI 10.1103/PhysRevB.62.6002 PG 13 WC Physics, Condensed Matter SC Physics GA 352JZ UT WOS:000089212900113 ER PT J AU Choi, HJ Rotenberg, E Kawakami, RK Bovensiepen, U Wolfe, JH Smith, NV Qiu, ZQ AF Choi, HJ Rotenberg, E Kawakami, RK Bovensiepen, U Wolfe, JH Smith, NV Qiu, ZQ TI Effect of interfacial roughness on the phase of quantum well states in Cu/Co(001) and Cu/Ni(001) systems SO PHYSICAL REVIEW B LA English DT Article ID FE/CR MULTILAYERS; PHOTOEMISSION; OSCILLATION; DICHROISM; FILMS; LEVEL AB It is known that the quantum well (QW) states in magnetic layered structures can be well described by a phase accumulation model (PAM) in which the phase is calculated by assuming a perfectly sharp interface. In order to verify the validity of this assumption, we studied the effect of interfacial mixing on the phase of QW states in Co/Cu/Co(001) and Co/Cu/Ni(001) systems. By controlling the annealing time, we progressively increased the interfacial mixing on these films. While the interlayer oscillatory coupling changes upon annealing, the coupling peak positions remain unchanged. This result suggests that the phase of the QW states have little dependence on the interfacial mixing. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Choi, HJ (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Rotenberg, Eli/B-3700-2009; Qiu, Zi Qiang/O-4421-2016; Bovensiepen, Uwe/E-7435-2017 OI Rotenberg, Eli/0000-0002-3979-8844; Qiu, Zi Qiang/0000-0003-0680-0714; Bovensiepen, Uwe/0000-0002-1506-4491 NR 15 TC 2 Z9 2 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 SEP 1 PY 2000 VL 62 IS 10 BP 6561 EP 6564 DI 10.1103/PhysRevB.62.6561 PG 4 WC Physics, Condensed Matter SC Physics GA 353ZB UT WOS:000089304400062 ER PT J AU Ren, Y Palstra, TTM Khomskii, DI Nugroho, AA Menovsky, AA Sawatzky, GA AF Ren, Y Palstra, TTM Khomskii, DI Nugroho, AA Menovsky, AA Sawatzky, GA TI Magnetic properties of YVO3 single crystals SO PHYSICAL REVIEW B LA English DT Article ID LAVO3; SUSCEPTIBILITY; ORDERINGS AB The magnetic properties of YVO3 single crystals have been studied in the temperature range from 350 to 4.2 K and in magnetic fields up to 7 T. It is found that in an applied field less than 4 kOe remarkable magnetization reversals occur at two distinct temperatures: an abrupt switch at T-s=77 K associated with a first-order structure phase transition and a gradual reversal at T*approximate to 95 K without a structural anomaly. Most interestingly, the magnetization always switches to the opposite direction if the crystal is cooled or warmed through T-s and T* in a field less than similar to 500 Oe. In higher magnetic fields the magnetization does not change sign but has a minimum at T* and a sudden change at T-s. A possible mechanism for the observed peculiar magnetic behavior is discussed, related to the competition of the single-ion magnetic anisotropy and the antisymmetric Dzyaloshinsky-Moriya interaction accompanied by a change of orbital ordering. C1 Univ Groningen, Solid State Phys Lab, Ctr Mat Sci, NL-9747 AG Groningen, Netherlands. Univ Groningen, Inorgan Solid State Chem Lab, Ctr Mat Sci, NL-9747 AG Groningen, Netherlands. Univ Amsterdam, Van Der Waals Zeeman Inst, NL-1018 XE Amsterdam, Netherlands. RP Ren, Y (reprint author), Argonne Natl Lab, MSD, Bldg 223, Argonne, IL 60439 USA. RI Nugroho, Agustinus Agung/E-5977-2010; Sawatzky, George/D-2997-2012; Palstra, Thomas/K-1961-2013 OI Nugroho, Agustinus Agung/0000-0002-1785-4008; Palstra, Thomas/0000-0001-5239-3115 NR 25 TC 106 Z9 109 U1 5 U2 21 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 2000 VL 62 IS 10 BP 6577 EP 6586 DI 10.1103/PhysRevB.62.6577 PG 10 WC Physics, Condensed Matter SC Physics GA 353ZB UT WOS:000089304400065 ER PT J AU Curro, NJ Hammel, PC Pagliuso, PG Sarrao, JL Thompson, JD Fisk, Z AF Curro, NJ Hammel, PC Pagliuso, PG Sarrao, JL Thompson, JD Fisk, Z TI Evidence for spiral magnetic order in the heavy fermion material CeRhIn5 SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTIVITY AB We report In-115 nuclear quadrupolar resonance measurements of the heavy fermion compound CeRhIn5 in the paramagnetic and antiferromagnetic states. The magnetic order is consistent with a model of helical modulation of the Ce moments that is incommensurate with the lattice, and the magnetic dynamics indicate possible two-dimensional behavior. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Natl HIgh Magnet Field Lab, Tallahassee, FL 32306 USA. Florida State Univ, Tallahassee, FL 32306 USA. RP Curro, NJ (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Pagliuso, Pascoal/C-9169-2012; Hammel, P Chris/O-4845-2014; Curro, Nicholas/D-3413-2009 OI Hammel, P Chris/0000-0002-4138-4798; Curro, Nicholas/0000-0001-7829-0237 NR 16 TC 58 Z9 58 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 1 PY 2000 VL 62 IS 10 BP R6100 EP R6103 DI 10.1103/PhysRevB.62.R6100 PG 4 WC Physics, Condensed Matter SC Physics GA 353ZB UT WOS:000089304400013 ER PT J AU Martin, I Balatsky, A AF Martin, I Balatsky, A TI Probing pseudogap by Josephson tunneling SO PHYSICAL REVIEW B LA English DT Article AB We propose here an experiment aimed to determine whether there are superconducting pairing fluctuations in the pseudogap regime of the high-T-c materials. In the experimental setup, two samples above T-c are brought into contact at a single point and the differential ac conductivity in the presence of a constant applied bias voltage between the samples, V, should be measured. We argue that the pairing fluctuations will produce randomly fluctuating Josephson current with zero mean, however, the current-current correlator will have a characteristic frequency given by Josephson frequency omega(J)=2eV1h. We predict that the differential ac conductivity and the Josephson microwave radiation should have peaks at the Josephson frequency with the width determined by the phase fluctuations time. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Martin, I (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 11 TC 6 Z9 6 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 2000 VL 62 IS 10 BP R6124 EP R6126 DI 10.1103/PhysRevB.62.R6124 PG 3 WC Physics, Condensed Matter SC Physics GA 353ZB UT WOS:000089304400019 ER PT J AU McCarthy, JE Duffy, JA Detlefs, C Cooper, MJ Canfield, PC AF McCarthy, JE Duffy, JA Detlefs, C Cooper, MJ Canfield, PC TI 4f spin density in the reentrant ferromagnet SmMn2Ge2 SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC-COMPTON-SCATTERING; ORBITAL MOMENT; CROSS-SECTION; MAGNETORESISTANCE; TEMPERATURE; TRANSITIONS; ELECTRONS; PRESSURE; NIO AB The spin contribution to the magnetic moment in SmMn2Ge2 has been measured by magnetic Compton scattering in both the low- and high-temperature ferromagnetic phases. At low temperature, the Sm site is shown to possess a large 4f spin moment of 3.4+/-0.1 mu(B), aligned antiparallel to the total magnetic moment. At high temperature, the data show conclusively that. ordered magnetic moments are present on the samarium site. C1 European Synchrotron Radiat Facil, F-38043 Grenoble, France. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Duffy, JA (reprint author), European Synchrotron Radiat Facil, BP 220, F-38043 Grenoble, France. RI Detlefs, Carsten/B-6244-2008; Canfield, Paul/H-2698-2014 OI Detlefs, Carsten/0000-0003-2573-2286; NR 26 TC 16 Z9 16 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 SEP 1 PY 2000 VL 62 IS 10 BP R6073 EP R6076 DI 10.1103/PhysRevB.62.R6073 PG 4 WC Physics, Condensed Matter SC Physics GA 353ZB UT WOS:000089304400006 ER PT J AU Blann, M Chadwick, MB AF Blann, M Chadwick, MB TI Precompound Monte-Carlo model for cluster induced reactions SO PHYSICAL REVIEW C LA English DT Article ID NUCLEAR-REACTIONS; DECAY MODEL AB We present an algorithm for Monte-Carlo selection of exciton energies for reactions induced by clusters. Reaction mechanisms are addressed that involve a dissolution of the cluster into its constituent nucleons Followed by the initiation of a preequilibrium cascade. Calculated single differential spectra and excitation functions for Nb-93(alpha,xn) reactions are compared with experimental results to illustrate use of this method. Some advantages of exclusive computational techniques over analytic inclusive methods are summarized. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Blann, M (reprint author), 7210E Calabria Court, San Diego, CA 92122 USA. NR 22 TC 11 Z9 11 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 2000 VL 62 IS 3 AR 034604 DI 10.1103/PhysRevC.62.034604 PG 5 WC Physics, Nuclear SC Physics GA 354TQ UT WOS:000089346100037 ER PT J AU Deb, PK Amos, K Karataglidis, S AF Deb, PK Amos, K Karataglidis, S TI First order optical potentials and 25 to 40 MeV proton elastic scattering SO PHYSICAL REVIEW C LA English DT Article ID MICROSCOPIC MODEL ANALYSES; BASIS SHELL-MODEL; DIVERSE MASS; NUCLEI; TARGETS AB The differential cross sections and analyzing powers from the elastic scattering of 25 and 40 MeV protons from many nuclei have been studied. Analyses have been made using a fully microscopic model of proton-nucleus scattering seeking to establish a means appropriate for use in analyses of radioactive beam scattering from hydrogen with ion energies 25A and 40A MeV. C1 Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. Univ Calif Los Alamos Natl Lab, Div Theory, Los Alamos, NM 87545 USA. RP Deb, PK (reprint author), Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. NR 31 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 2000 VL 62 IS 3 AR 037601 DI 10.1103/PhysRevC.62.037601 PG 4 WC Physics, Nuclear SC Physics GA 354TQ UT WOS:000089346100055 ER PT J AU Ding, KY Cizewski, JA Seweryniak, D Amro, H Carpenter, MP Davids, CN Fotiades, N Janssens, RVF Lauritsen, T Lister, CJ Nisius, D Reiter, P Uusitalo, J Wiedenhover, I Macchiavelli, AO AF Ding, KY Cizewski, JA Seweryniak, D Amro, H Carpenter, MP Davids, CN Fotiades, N Janssens, RVF Lauritsen, T Lister, CJ Nisius, D Reiter, P Uusitalo, J Wiedenhover, I Macchiavelli, AO TI High-spin excitations in Hf-158,Hf-159,Hf-160 from recoil-decay tagging SO PHYSICAL REVIEW C LA English DT Article ID NEUTRON-CORE BREAKING; STRUCTURAL-CHANGES; STATES; NUCLEI; YB-158; SPECTROSCOPY; SYSTEMATICS; COEXISTENCE; SHAPE; BAND AB The 270-MeV Ni-58 + Pd-A reaction was used for the first recoil-decay tagging measurement with Gamma-sphere coupled to the Fragment Mass Analyzer at Argonne National Laboratory. Level structures of Hf-158 and Hf-159 are identified for the first time, and that of Hf-160 is extended. The systematical behavior of the energy levels in neighboring isotones and isotopes, as well as the aligned angular momenta as a function of rotational frequency, are examined. C1 Rutgers State Univ, Dept Phys & Astron, New Brunswick, NJ 08903 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Ding, KY (reprint author), Telecordia Technol, Piscataway, NJ 08854 USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 33 TC 17 Z9 18 U1 2 U2 17 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 2000 VL 62 IS 3 AR 034316 DI 10.1103/PhysRevC.62.034316 PG 14 WC Physics, Nuclear SC Physics GA 354TQ UT WOS:000089346100030 ER PT J AU Pfohl, J Laird, RW Riley, MA Kondev, FG Archer, DE Brown, TB Clark, RM Devlin, M Fallon, P Hartley, DJ Hibbert, IM Joss, DT LaFosse, DR Nolan, PJ O'Brien, NJ Paul, ES Sarantites, DG Sheline, RK Shepherd, SL Simpson, J Wadsworth, R Sun, Y Afanasjev, AV Ragnarsson, I AF Pfohl, J Laird, RW Riley, MA Kondev, FG Archer, DE Brown, TB Clark, RM Devlin, M Fallon, P Hartley, DJ Hibbert, IM Joss, DT LaFosse, DR Nolan, PJ O'Brien, NJ Paul, ES Sarantites, DG Sheline, RK Shepherd, SL Simpson, J Wadsworth, R Sun, Y Afanasjev, AV Ragnarsson, I TI Highly deformed rotational structures in Pm-136 SO PHYSICAL REVIEW C LA English DT Article ID SUPERDEFORMED BANDS; LIFETIME MEASUREMENTS; ENHANCED-DEFORMATION; MASS REGION; NUCLEI; ND-135; MOMENT; PR-134; DECAY AB Four highly deformed structures in the odd-odd nucleus Pm-136(61)75 were observed via the Pd-105(Cl-35,2p2n) reaction at 180 and 173 MeV using the GAMMASPHERE gamma-ray spectrometer and the Microball charged-particle detector array. Quadrupole moment measurements were performed on all of the bands. In contrast to lighter odd-Z Pm and Pr nuclei, bands based on the g(9/2)[404]9/2 proton orbital were not observed. Instead, the four observed sequences are assigned as a coupling Df an i(13/2) neutron with the low-Omega h(11/2) and mixed d(5/2)g(7/2) orbitals. Comparisons with neighboring highly deformed structures are discussed and cranked Nilsson-Strutinsky calculations for Pm-136 are presented. C1 Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Univ York, Dept Phys, York YO1 5DD, N Yorkshire, England. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. SERC, Daresbury Lab, CLRC, Warrington WA4 4AD, Cheshire, England. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Lund Inst Technol, Dept Math Phys, S-22100 Lund, Sweden. RP Pfohl, J (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Devlin, Matthew/B-5089-2013; Sun, Yang/P-2417-2015 OI Devlin, Matthew/0000-0002-6948-2154; NR 35 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 2000 VL 62 IS 3 AR 031304 DI 10.1103/PhysRevC.62.031304 PG 5 WC Physics, Nuclear SC Physics GA 354TQ UT WOS:000089346100004 ER PT J AU Pisarski, RD AF Pisarski, RD TI Critical line for H superfluidity in strange quark matter? art. no. 035202 SO PHYSICAL REVIEW C LA English DT Article ID ELECTROWEAK PHASE-TRANSITION; FIRST-ORDER TRANSITIONS; CUBIC ANISOTROPY MODEL; FINITE-TEMPERATURE QCD; EPSILON-EXPANSION ANALYSIS; COLOR-FLAVOR LOCKING; HIGH-DENSITY QCD; BARYON DENSITY; GAUGE-THEORIES; RENORMALIZATION-GROUP AB Based upon the analogy to the electroweak phase diagram, I propose that in QCD there might be a critical line for a superfluid transition. in the plane of chemical potential and temperature. The order parameter has the quantum numbers of the H dibaryon, but the transition is driven by color superconductivity in strange quark matter. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM pisarski@bnl.gov NR 100 TC 23 Z9 23 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 2000 VL 62 IS 3 AR 035202 DI 10.1103/PhysRevC.62.035202 PG 11 WC Physics, Nuclear SC Physics GA 354TQ UT WOS:000089346100046 ER PT J AU Podolyak, Z Walker, PM Cullen, DM Dracoulis, GD Fallon, P Fairchild, B Hauschild, K Macchiavelli, AO McNabb, DP Savelius, A Ward, D Wheldon, C AF Podolyak, Z Walker, PM Cullen, DM Dracoulis, GD Fallon, P Fairchild, B Hauschild, K Macchiavelli, AO McNabb, DP Savelius, A Ward, D Wheldon, C TI Search for very long-lived isomers in the hafnium-tungsten region SO PHYSICAL REVIEW C LA English DT Article ID MULTI-QUASI-PARTICLE; INTRINSIC STATES; BLOCKING; TA-176; FUSION; TRAPS AB Targets of Ca-48 have been bombarded with Xe-134,Xe-136 beams as part of a search for long-lived, high-K states in well-deformed nuclei with A approximate to 180. Several known isomers were observed bir off-line gamma-ray detection, and limits have been established for high-g isomer production in various isotopes of hafnium (A=175-178), tantalum (A = 177-181), and tungsten (A = 177-181). C1 Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England. Univ Liverpool, Oliver Lodge Lab, Dept Phys, Liverpool L69 7ZE, Merseyside, England. Australian Natl Univ, Res Sch Phys Sci & Engn, Dept Nucl Phys, Canberra, ACT 0200, Australia. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Jyvaskyla, Dept Phys, F-40351 Jyvaskyla, Finland. RP Podolyak, Z (reprint author), Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England. RI Dracoulis, George/A-8123-2008; Hauschild, Karl/A-6726-2009; Wheldon, Carl/F-9203-2013 NR 33 TC 1 Z9 1 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 2000 VL 62 IS 3 AR 034303 PG 10 WC Physics, Nuclear SC Physics GA 354TQ UT WOS:000089346100017 ER PT J AU Schaffner-Bielich, J Gal, A AF Schaffner-Bielich, J Gal, A TI Properties of strange hadronic matter in bulk and in finite systems SO PHYSICAL REVIEW C LA English DT Article ID MULTI-LAMBDA MATTER; MESON COUPLING MODEL; DOUBLE HYPERNUCLEUS; NUCLEAR-MATTER; QUARK MATTER; BOUND-STATE; HYPERON; POTENTIALS AB The hyperon-hyperon potentials due to a recent SU(3) Nijmegen soft-core potential model are incorporated within a relativistic mean field calculation of strange hadronic matter. We find considerably higher binding energy in bulk matter compared to several recent calculations which constrain the composition of matter. For small strangeness fractions (f(S)less than or similar to 1), matter is dominated by N Lambda Xi composition and the calculated binding energy closely follows that calculated by using the hyperon potentials of our previous calculations. For larger strangeness fractions (f(S)greater than or similar to 1), the calculated binding energy increases substantially beyond any previous calculation due to a phase transition into N Sigma Xi dominated matter. We also compare bulk matter calculations with finite system calculations, again highlighting the consequences of reducing the Coulomb destabilizing effects in finite strange systems. C1 Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. RP Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. NR 42 TC 152 Z9 156 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 2000 VL 62 IS 3 AR 034311 DI 10.1103/PhysRevC.62.034311 PG 8 WC Physics, Nuclear SC Physics GA 354TQ UT WOS:000089346100025 ER PT J AU Abbott, B Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Ahn, S Akimov, V Alves, GA Amos, N Anderson, EW Baarmand, MM Babintsev, VV Babukhadia, L Baden, A Baldin, B Banerjee, S Bantly, J Barberis, E Baringer, P Bartlett, JF Bassler, U Belyaev, A Beri, SB Bernardi, G Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Boehnlein, A Bojko, NI Borcherding, F Brandt, A Breedon, R Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Buescher, V Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chan, KM Cheliulaev, SV Chen, LP Chen, W Cho, DK Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Connolly, B Cooper, WE Coppage, D Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Dyshkant, A Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Estrada, J Evans, H Evdokimov, VN Fahland, T Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gilmartin, R Ginther, G Gobbi, B Gomez, B Gomez, G Gonchalrov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Green, JA Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hays, C Hebert, C Hedin, D Heinson, AP Heintz, U Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Kahn, S Kajfasz, E Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Knuteson, B Ko, W Kohli, JM Koltick, D Kostritski, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Landsberg, G Leflat, A Lehner, F Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Lundstedt, C Maciel, AKA Madaras, RJ Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Martin, RD Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montomery, HE Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Neal, HA Negret, JP Negroni, S Norman, D Oesch, L Oguri, V Olivier, B Oshima, N Owen, D Padley, P Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pischalnikov, Y Pope, BG Popkov, E Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Reay, NW Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Sculli, J Sen, N Shabalina, E Shankar, HC Shivpuri, RK Shpakov, D Shupe, M Sidwell, RA Singh, H Singh, JB Sirotenko, V Slattery, P Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Song, XF Sorin, V Sosebee, M Sotnikova, N Souza, M Stanton, NR Steinbruck, G Stephens, RW Stevenson, ML Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Stutte, L Sznajder, A Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Toback, D Trippe, TG Turcot, AS Tuts, PM van Gemmeren, P Vaniev, V Varelas, N Volkov, AA Vorobiev, AP Wahl, HD Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Wood, DR Yamada, R Yamin, P Yasuda, T Yip, K Youssef, S Yu, J Yu, Y Zanabria, M Zheng, H Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A AF Abbott, B Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Ahn, S Akimov, V Alves, GA Amos, N Anderson, EW Baarmand, MM Babintsev, VV Babukhadia, L Baden, A Baldin, B Banerjee, S Bantly, J Barberis, E Baringer, P Bartlett, JF Bassler, U Belyaev, A Beri, SB Bernardi, G Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Boehnlein, A Bojko, NI Borcherding, F Brandt, A Breedon, R Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Buescher, V Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chan, KM Cheliulaev, SV Chen, LP Chen, W Cho, DK Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Connolly, B Cooper, WE Coppage, D Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Dyshkant, A Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Estrada, J Evans, H Evdokimov, VN Fahland, T Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gilmartin, R Ginther, G Gobbi, B Gomez, B Gomez, G Gonchalrov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Green, JA Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hays, C Hebert, C Hedin, D Heinson, AP Heintz, U Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Kahn, S Kajfasz, E Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Knuteson, B Ko, W Kohli, JM Koltick, D Kostritski, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Landsberg, G Leflat, A Lehner, F Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Lundstedt, C Maciel, AKA Madaras, RJ Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Martin, RD Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montomery, HE Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Neal, HA Negret, JP Negroni, S Norman, D Oesch, L Oguri, V Olivier, B Oshima, N Owen, D Padley, P Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pischalnikov, Y Pope, BG Popkov, E Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Reay, NW Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Sculli, J Sen, N Shabalina, E Shankar, HC Shivpuri, RK Shpakov, D Shupe, M Sidwell, RA Singh, H Singh, JB Sirotenko, V Slattery, P Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Song, XF Sorin, V Sosebee, M Sotnikova, N Souza, M Stanton, NR Steinbruck, G Stephens, RW Stevenson, ML Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Stutte, L Sznajder, A Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Toback, D Trippe, TG Turcot, AS Tuts, PM van Gemmeren, P Vaniev, V Varelas, N Volkov, AA Vorobiev, AP Wahl, HD Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Wood, DR Yamada, R Yamin, P Yasuda, T Yip, K Youssef, S Yu, J Yu, Y Zanabria, M Zheng, H Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A TI Limits on anomalous WW gamma and WWZ couplings from WW/WZ -> evjj production SO PHYSICAL REVIEW D LA English DT Article ID GAUGE-BOSON COUPLINGS; ALPHA-S CALCULATION; ROOT-S=1.8 TEV; P(P)OVER-BAR COLLISIONS; FERMILAB-TEVATRON; PAIR PRODUCTION; WZ PRODUCTION; W+W PRODUCTION; D0 DETECTOR; COLLIDER AB Limits on anomalous WW gamma and WWZ couplings are presented from a study of WW/WZ-->evjj events produced in p (p) over bar collisions at root s=1.8 TeV. Results from the analysis of data collected using the DO detector during the 1993-1995 Tevatron collider run at Fermilab are combined with those of an earlier study from the 1992-1993 run. A fit to the transverse momentum spectrum of the W boson yields direct limits on anomalous WW gamma and WWZ couplings. With the assumption that the WW gamma and WWZ couplings are equal, we obtain -0.34 < lambda < 0.36 (with Delta kappa = 0) and -0.43 < Delta kappa < 0.59 (with lambda = 0) at the 95% confidence level for a form-factor scale Lambda = 2.0 TeV. C1 NYU, New York, NY 10003 USA. Univ Buenos Aires, Buenos Aires, DF, Argentina. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. Univ Estado Rio de Janeiro, Rio De Janeiro, Brazil. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Los Andes, Bogota, Colombia. Univ San Francisco Quito, Quito, Ecuador. Univ Grenoble 1, Inst Sci Nucl, CNRS, IN2P3, Grenoble, France. Ctr Phys Particules Marseille, CNRS, IN2P3, Marseille, France. Univ Paris 06, LPNHE, Paris, France. Univ Paris 07, CNRS, IN2P3, Paris, France. CEA, Serv Phys Particules, DAPNIA, Saclay, France. Panjab Univ, Chandigarh 160014, India. Univ Delhi, Delhi 110007, India. Tata Inst Fundamental Res, Mumbai, India. Seoul Natl Univ, Seoul, South Korea. CINVESTAV, Mexico City 14000, DF, Mexico. Inst Nucl Phys, Krakow, Poland. Inst Theoret & Expt Phys, Moscow 117259, Russia. Moscow State Univ, Moscow, Russia. Inst High Energy Phys, Protvino, Russia. Univ Lancaster, Lancaster, England. Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Davis, Davis, CA 95616 USA. Calif State Univ Fresno, Fresno, CA 93740 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Hawaii, Honolulu, HI 96822 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Illinois, Chicago, IL 60607 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northwestern Univ, Evanston, IL 60208 USA. Indiana Univ, Bloomington, IN 47405 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Purdue Univ, W Lafayette, IN 47907 USA. Iowa State Univ, Ames, IA 50011 USA. Univ Kansas, Lawrence, KS 66045 USA. Kansas State Univ, Manhattan, KS 66506 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Univ Maryland, College Pk, MD 20742 USA. Boston Univ, Boston, MA 02215 USA. Northeastern Univ, Boston, MA 02115 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Nebraska, Lincoln, NE 68588 USA. Columbia Univ, New York, NY 10027 USA. Univ Rochester, Rochester, NY 14627 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Langston Univ, Langston, OK 73050 USA. Univ Oklahoma, Norman, OK 73019 USA. Brown Univ, Providence, RI 02912 USA. Univ Texas, Arlington, TX 76019 USA. Texas A&M Univ, College Stn, TX 77843 USA. Rice Univ, Houston, TX 77005 USA. Univ Washington, Seattle, WA 98195 USA. RP Abbott, B (reprint author), NYU, New York, NY 10003 USA. RI Sznajder, Andre/L-1621-2016; Chekulaev, Sergey/O-1145-2015; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Dudko, Lev/D-7127-2012; Alves, Gilvan/C-4007-2013; Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015; Leflat, Alexander/D-7284-2012; Merkin, Mikhail/D-6809-2012; Yip, Kin/D-6860-2013; Kuleshov, Sergey/D-9940-2013; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013 OI Sznajder, Andre/0000-0001-6998-1108; Dudko, Lev/0000-0002-4462-3192; Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775; Yip, Kin/0000-0002-8576-4311; Kuleshov, Sergey/0000-0002-3065-326X; De, Kaushik/0000-0002-5647-4489; NR 49 TC 17 Z9 17 U1 0 U2 4 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 1 PY 2000 VL 62 IS 5 AR 052005 DI 10.1103/PhysRevD.62.052005 PG 18 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500009 ER PT J AU Akushevich, I Kuraev, EA Shaikhatdenov, BG AF Akushevich, I Kuraev, EA Shaikhatdenov, BG TI QED correction to the radiative tail from the elastic peak in deep inelastic scattering SO PHYSICAL REVIEW D LA English DT Article ID LEPTON-NUCLEON-SCATTERING; ELECTROMAGNETIC CORRECTIONS; POLARIZED PARTICLES; HERA ENERGIES; HEAVY PHOTON; TENSOR; ORDER; EP AB We calculate the deep inelastic scattering (DIS) cross section under kinematical requirements when a final hadron state is a single proton. The process in the lowest order is known as the radiative tail from the elastic peak. We take into account the correction, coming from the emission of virtual and soft real photons, to the amplitude of this process as well as the one induced by the emission of an additional hard photon and a hard pair. The resulting contributions of these channels are presented in the leading and, partly, next-to-leading logarithmic approximations. Some general expressions for the photon contributions are given. Numerical results are presented for kinematical conditions of the current experiments in DIS. C1 N Carolina Cent Univ, Durham, NC 27707 USA. TJNAF, Newport News, VA 23606 USA. Joint Inst Nucl Res, Dubna 141980, Russia. RP Akushevich, I (reprint author), N Carolina Cent Univ, Durham, NC 27707 USA. NR 25 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 2000 VL 62 IS 5 AR 053016 DI 10.1103/PhysRevD.62.053016 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500025 ER PT J AU Aloisio, R Blasi, P Ghia, PL Grillo, AF AF Aloisio, R Blasi, P Ghia, PL Grillo, AF TI Probing the structure of space-time with cosmic rays SO PHYSICAL REVIEW D LA English DT Article ID QUANTUM-GRAVITY; TEV; MARKARIAN-421; UNIVERSE; SPECTRA AB The study of the interactions of cosmic rays (CR's) with universal diffuse background radiation can provide very stringent rests of the validity of special relativity. The interactions we consider are the ones characterized by well defined energy thresholds whose energy position can be predicted on the basis of special relativity. We argue that the experimental confirmation of the existence of these thresholds can in principle put very stringent limits on the scale where special relativity and/or continuity of space-time may possibly break down. C1 Univ Aquila, Dipartimento Fis, I-67100 Laquila, Italy. Fermilab Natl Accelerator Lab, NASA Fermilab Astrophys Grp, Batavia, IL 60510 USA. CNR, Ist Cosmogeofis, I-10133 Turin, Italy. Ist Nazl Fis Nucl, Lab Nazl Gran Sasso, Laquila, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. RP Univ Aquila, Dipartimento Fis, Via Vetoio, I-67100 Laquila, Italy. RI Aloisio, Roberto/I-9533-2012; Blasi, Pasquale/O-9345-2015 OI Aloisio, Roberto/0000-0003-0161-5923; Blasi, Pasquale/0000-0003-2480-599X NR 41 TC 147 Z9 149 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 2000 VL 62 IS 5 AR 053010 DI 10.1103/PhysRevD.62.053010 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500019 ER PT J AU Ambrogiani, M Argiro, S Bagnasco, S Baldini, W Bettoni, D Borreani, G Buzzo, A Calabrese, R Ceccucci, A Cester, R Dalpiaz, P Fan, X Garzoglio, G Gollwitzer, KE Hahn, A Jin, S Kasper, J Lasio, G Lo Vetere, M Luppi, E Maas, P Macri, M Mandelkern, M Marchetto, F Marinelli, M Marsh, W Martini, M Menichetti, E Mussa, R Obertino, MM Pallavicini, M Pastrone, N Patrignani, C Pedlar, TK Peoples, J Pordes, S Robutti, E Roccuzzo, B Rosen, J Rumerio, P Santroni, A Savrie, M Schultz, J Seth, KK Stancari, G Stancari, M Streets, J Tomaradze, A Werkema, S Zioulas, G AF Ambrogiani, M Argiro, S Bagnasco, S Baldini, W Bettoni, D Borreani, G Buzzo, A Calabrese, R Ceccucci, A Cester, R Dalpiaz, P Fan, X Garzoglio, G Gollwitzer, KE Hahn, A Jin, S Kasper, J Lasio, G Lo Vetere, M Luppi, E Maas, P Macri, M Mandelkern, M Marchetto, F Marinelli, M Marsh, W Martini, M Menichetti, E Mussa, R Obertino, MM Pallavicini, M Pastrone, N Patrignani, C Pedlar, TK Peoples, J Pordes, S Robutti, E Roccuzzo, B Rosen, J Rumerio, P Santroni, A Savrie, M Schultz, J Seth, KK Stancari, G Stancari, M Streets, J Tomaradze, A Werkema, S Zioulas, G TI Study of the gamma gamma decays of the chi(c2)(1(3)P(2)) and chi(c omicron)(1(3)P(omicron)) charmonium resonances SO PHYSICAL REVIEW D LA English DT Article ID PHOTON-PHOTON COLLISIONS; 2-PHOTON COLLISIONS; PARTIAL-WIDTH; FERMILAB; ANNIHILATIONS; QUARKONIA; CHI(C2); PROTON; STATES; QCD AB We report the branching ratios of the chi(c2)(1(3)P(2)) and chi(c0)(1(3)P(0)) charmonium resonances to two photons using event samples collected by Fermilab experiment E835 in the reactions (p) over bar p --> chi(c2)(1(3)P(2))[chi(c0)(1(3)P(0))] Our result for the chi(c2) is B(chi(c2) --> gamma gamma) = (1.35 +/- 0.25 +/- 0.12) X 10(-4). We set a 95% upper limit for the chi(c0) branching ratio B(chi(c0) --> gamma gamma) at 2.09 X 10(-4). C1 Ist Nazl Fis Nucl, I-44100 Ferrara, Italy. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Ferrara, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Univ Genoa, I-16146 Genoa, Italy. Univ Calif Irvine, Irvine, CA 92697 USA. Northwestern Univ, Evanston, IL 60208 USA. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Turin, I-10125 Turin, Italy. RP Ambrogiani, M (reprint author), Ist Nazl Fis Nucl, I-44100 Ferrara, Italy. RI Patrignani, Claudia/C-5223-2009; Lo Vetere, Maurizio/J-5049-2012; Luppi, Eleonora/A-4902-2015; Pallavicini, Marco/G-5500-2012; Calabrese, Roberto/G-4405-2015 OI Patrignani, Claudia/0000-0002-5882-1747; Lo Vetere, Maurizio/0000-0002-6520-4480; Luppi, Eleonora/0000-0002-1072-5633; Pallavicini, Marco/0000-0001-7309-3023; Calabrese, Roberto/0000-0002-1354-5400 NR 37 TC 32 Z9 32 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 1 PY 2000 VL 62 IS 5 AR 052002 DI 10.1103/PhysRevD.62.052002 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500006 ER PT J AU Atwood, D Bar-Shalom, S Soni, A AF Atwood, D Bar-Shalom, S Soni, A TI Dijet production at hadron colliders in theories with large extra dimensions SO PHYSICAL REVIEW D LA English DT Article ID SCALE QUANTUM-GRAVITY; DEEP-INELASTIC SCATTERING; LARGE COMPACT DIMENSIONS; GAMMA-GAMMA; E(+)E(-) COLLIDERS; SPACE DIMENSIONS; PAIR PRODUCTION; TEV; COMPACTIFICATION; CONSTRAINTS AB We consider the production of high invariant mass jet pairs at hadron colliders as a test for TeV scale gravitational effects. We find that this signal can probe effective Planck masses of about 10 TeV at the CERN LHC with a center of mass energy of 14 TeV and 1.5 TeV at the Fermilab Tevatron with a center of mass energy of 2 TeV. These results are compared to analogous scattering processes at leptonic colliders. C1 Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Univ Rome La Sapienza, Ist Nazl Fis Nucl, Sez Roma 1, Rome, Italy. Univ Rome La Sapienza, Dept Phys, Rome, Italy. Brookhaven Natl Lab, Theory Grp, Upton, NY 11973 USA. RP Atwood, D (reprint author), Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. EM atwood@iastate.edu; Shaouly.BarShalom@Roma1.infn.it; soni@bnl.gov NR 71 TC 21 Z9 21 U1 0 U2 0 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 1 PY 2000 VL 62 IS 5 AR 056008 DI 10.1103/PhysRevD.62.056008 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500090 ER PT J AU Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Stepaniak, CJ Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Eckhart, E Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Pedlar, TK Schwarthoff, H Thayer, JB von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Kopp, S Mahmood, AH Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D McGee, S Perera, LP Zhou, GJ Lipeles, E Pappas, SP Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Hill, TS Morrison, RJ Briere, RA Ferguson, T Vogel, H Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A AF Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Stepaniak, CJ Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Eckhart, E Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Pedlar, TK Schwarthoff, H Thayer, JB von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Kopp, S Mahmood, AH Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D McGee, S Perera, LP Zhou, GJ Lipeles, E Pappas, SP Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Hill, TS Morrison, RJ Briere, RA Ferguson, T Vogel, H Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A TI Study of exclusive two-body B-omicron meson decays to charmonium SO PHYSICAL REVIEW D LA English DT Article ID CP-VIOLATION; DETECTOR AB We present a study of three B-o decay modes useful for time-dependent CP asymmetry measurements. From a sample of 9.7x10(6) B (B) over bar meson pairs collected with the CLEO detector, we have reconstructed B-o --> J/psi K-s(o), B-o-->chi(c1) K-s(o), and B-o --> J/psi pi(o) decays. The latter two decay modes have been observed for the first time. We describe a K-s(o)-->pi(o)pi(o) detection technique and its application to the reconstruction of the decay B-o --> J/psi K-s(o). Combining the results obtained using K-s(o)-->pi(+)pi(-) and K-s(o)-->pi(o)pi(o) decays, we determine B(B-o -->J/psi K-o)= (9.5+/-0.8+/-0.6) x 10(-4), where the first uncertainty is statistical and the second one is systematic. We also obtain B(B-o-->chi(c1)K(o))=(3.9(-1.3)(+1.9) +/-0.4) x 10(-4) and B(B-o-->J/psi pi(o)) = (2.5(-0.9)(+1.1) +/- 0.2)x 10(-5). C1 Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. Inst Particle Phys, Montreal, PQ, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Univ Texas, Austin, TX 78712 USA. Univ Texas Pan Amer, Edinburg, TX 78539 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. MIT, Cambridge, MA 02139 USA. RP Avery, P (reprint author), Univ Florida, Gainesville, FL 32611 USA. RI Warburton, Andreas/N-8028-2013; Briere, Roy/N-7819-2014; Vogel, Helmut/N-8882-2014; Ferguson, Thomas/O-3444-2014; OI Warburton, Andreas/0000-0002-2298-7315; Briere, Roy/0000-0001-5229-1039; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Poling, Ronald/0000-0001-7305-4702 NR 22 TC 10 Z9 10 U1 1 U2 2 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 1 PY 2000 VL 62 IS 5 AR 051101 DI 10.1103/PhysRevD.62.051101 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500001 ER PT J AU Bai, JZ Ban, Y Bian, JG Blum, I Chen, GP Chen, HF Chen, J Chen, JC Chen, Y Chen, YB Chen, YQ Cheng, BS Cui, XZ Ding, HL Dong, LY Du, ZZ Dunwoodie, W Gao, CS Gao, ML Gao, SQ Gratton, P Gu, JH Gu, SD Gu, WX Gu, YF Guo, YN Guo, ZJ Han, SW Han, Y Harris, FA He, J He, JT He, KL He, M Heng, YK Hitlin, DG Hu, GY Hu, HM Hu, JL Hu, QH Hu, T Hu, XQ Huang, YZ Huang, GS Izen, JM Jiang, CH Jin, Y Jones, BD Ju, X Ke, ZJ Kelsey, MH Kim, BK Kong, D Lai, YF Lang, PF Lankford, A Li, CG Li, D Li, HB Li, J Li, JC Li, PQ Li, RB Li, W Li, WG Li, XH Li, XN Liu, HM Liu, J Liu, RG Liu, Y Lou, XC Lowery, B Lu, F Lu, JG Luo, XL Ma, EC Ma, JM Malchow, R Mandelkern, M Mao, HS Mao, ZP Meng, XC Nie, J Olsen, SL Oyang, J Paluselli, D Pan, LJ Panetta, J Porter, F Qi, ND Qi, XR Qian, CD Qiu, JF Qu, YH Que, YK Rong, G Schernau, M Schmid, B Schultz, J Shao, YY Shen, BW Shen, DL Shen, H Shen, XY Sheng, HY Shi, HZ Song, XF Standifird, J Stoker, D Sun, F Sun, HS Sun, Y Sun, YZ Tang, SQ Toki, W Tong, GL Varner, GS Wang, F Wang, LS Wang, LZ Wan, M Wang, P Wang, PL Wang, SM Wang, TJ Wang, YY Weaver, M Wei, CL Wu, N Wu, YG Xi, DM Xia, XM Xie, PP Xie, Y Xie, YH Xu, GF Xue, ST Yan, J Yan, WG Yang, CM Yang, CY Yang, HX Yang, J Yang, W Yang, XF Ye, MH Ye, SW Ye, YX Yu, CS Yu, CX Yu, GW Yu, YH Yu, ZQ Yuan, CZ Yuan, Y Zhang, BY Zhang, C Zhang, CC Zhang, DH Zhang, DH Zhang, HL Zhang, J Zhang, JW Zhang, L Zhang, LS Zhang, P Zhang, QJ Zhang, SQ Zhang, XY Zhang, YY Zhao, DX Zhao, HW Zhao, JW Zhao, M Zhao, WR Zhao, ZG Zheng, JP Zheng, LS Zheng, ZP Zhou, BQ Zhou, GP Zhou, HS Zhou, L Zhu, KJ Zhu, QM Zhu, YC Zhu, YS Zhuang, BA AF Bai, JZ Ban, Y Bian, JG Blum, I Chen, GP Chen, HF Chen, J Chen, JC Chen, Y Chen, YB Chen, YQ Cheng, BS Cui, XZ Ding, HL Dong, LY Du, ZZ Dunwoodie, W Gao, CS Gao, ML Gao, SQ Gratton, P Gu, JH Gu, SD Gu, WX Gu, YF Guo, YN Guo, ZJ Han, SW Han, Y Harris, FA He, J He, JT He, KL He, M Heng, YK Hitlin, DG Hu, GY Hu, HM Hu, JL Hu, QH Hu, T Hu, XQ Huang, YZ Huang, GS Izen, JM Jiang, CH Jin, Y Jones, BD Ju, X Ke, ZJ Kelsey, MH Kim, BK Kong, D Lai, YF Lang, PF Lankford, A Li, CG Li, D Li, HB Li, J Li, JC Li, PQ Li, RB Li, W Li, WG Li, XH Li, XN Liu, HM Liu, J Liu, RG Liu, Y Lou, XC Lowery, B Lu, F Lu, JG Luo, XL Ma, EC Ma, JM Malchow, R Mandelkern, M Mao, HS Mao, ZP Meng, XC Nie, J Olsen, SL Oyang, J Paluselli, D Pan, LJ Panetta, J Porter, F Qi, ND Qi, XR Qian, CD Qiu, JF Qu, YH Que, YK Rong, G Schernau, M Schmid, B Schultz, J Shao, YY Shen, BW Shen, DL Shen, H Shen, XY Sheng, HY Shi, HZ Song, XF Standifird, J Stoker, D Sun, F Sun, HS Sun, Y Sun, YZ Tang, SQ Toki, W Tong, GL Varner, GS Wang, F Wang, LS Wang, LZ Wan, M Wang, P Wang, PL Wang, SM Wang, TJ Wang, YY Weaver, M Wei, CL Wu, N Wu, YG Xi, DM Xia, XM Xie, PP Xie, Y Xie, YH Xu, GF Xue, ST Yan, J Yan, WG Yang, CM Yang, CY Yang, HX Yang, J Yang, W Yang, XF Ye, MH Ye, SW Ye, YX Yu, CS Yu, CX Yu, GW Yu, YH Yu, ZQ Yuan, CZ Yuan, Y Zhang, BY Zhang, C Zhang, CC Zhang, DH Zhang, DH Zhang, HL Zhang, J Zhang, JW Zhang, L Zhang, LS Zhang, P Zhang, QJ Zhang, SQ Zhang, XY Zhang, YY Zhao, DX Zhao, HW Zhao, JW Zhao, M Zhao, WR Zhao, ZG Zheng, JP Zheng, LS Zheng, ZP Zhou, BQ Zhou, GP Zhou, HS Zhou, L Zhu, KJ Zhu, QM Zhu, YC Zhu, YS Zhuang, BA TI Direct measurement of B(D-omicron ->phi Chi(omicron)) and B(D+->phi Chi(+)) SO PHYSICAL REVIEW D LA English DT Article AB The first measurement of B(D-0 --> phi X-0) and an upper limit for B(D+ --> phi X+) are determined from 22.3 pb(-1) of e(+)e(-) annihilation data at a c.m. energy of 4.03 GeV. The data were recorded by the Beijing Spectrometer (BES) at BEPC. A recoil charge method is applied to charm threshold data to determine the charge of the D meson in the recoil from 9054+/-309+/-416 reconstructed D-0, D+ mesons. The branching fractions B(D0 --> phi X-0) = (1.71(-0.71)(+0.76) +/- 0.17)%, and B(D+ --> phi X+) < 1.8% are determined from 10 events with a reconstructed D and a recoiling phi. In addition, a 90% C.L. upper limit of B(D+ --> phi e(+)X(0)) < 1.6% is determined from a search for semileptonic decays of the D+. C1 Inst High Energy Phys, Beijing 100039, Peoples R China. CALTECH, Pasadena, CA 91125 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Hangzhou Univ, Hangzhou 310028, Peoples R China. Peking Univ, Beijing 100871, Peoples R China. Shandong Univ, Jinan 250100, Peoples R China. Shanghai Jiao Tong Univ, Shanghai 200030, Peoples R China. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Hawaii, Honolulu, HI 96822 USA. Univ Calif Irvine, Irvine, CA 92717 USA. Univ Sci & Technol China, Hefei 230026, Peoples R China. Univ Texas, Richardson, TX 75083 USA. RP Bai, JZ (reprint author), Inst High Energy Phys, Beijing 100039, Peoples R China. RI Chen, Yu/E-3788-2012 NR 8 TC 0 Z9 0 U1 0 U2 4 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 1 PY 2000 VL 62 IS 5 AR 052001 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500005 ER PT J AU Carena, M Mrenna, S Wagner, CEM AF Carena, M Mrenna, S Wagner, CEM TI Complementarity of the CERN LEP collider, the Fermilab Tevatron, and the CERN LHC in the search for a light MSSM Higgs boson SO PHYSICAL REVIEW D LA English DT Article ID SUPERSYMMETRIC STANDARD MODEL; RADIATIVE-CORRECTIONS; HADRON COLLIDERS; QCD CORRECTIONS; MASS; UNIFICATION; PHENOMENOLOGY; COUPLINGS; DECAYS; FUSION AB We study the discovery potential of the CERN LHC, Fermilab Tevatron and CERN LEP colliders in the search for the neutral CP-even Higgs boson of the MSSM which couples to the weak gauge bosons with a strength close to the standard model one and, hence, plays a relevant role in the mechanism of electroweak symmetry breaking. We place special emphasis on the radiative effects which influence the discovery reach of these colliders. We concentrate on the Vb (b) over bar channel, with V = Z or W, and on the channels with diphoton final states, which are the dominant ones for the search for a light standard model Higgs boson at LEP or Tevatron and LHC, respectively. By analyzing the parameters of the MSSM for which the searches become difficult at one or more of these three colliders, we demonstrate their complementarity in the search for a light Higgs boson which plays a relevant role in the mechanism of electroweak symmetry breaking. C1 CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Carena, M (reprint author), CERN, Div Theory, CH-1211 Geneva 23, Switzerland. EM Carlos.Wagner@cern.ch NR 54 TC 93 Z9 93 U1 0 U2 0 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 1 PY 2000 VL 62 IS 5 AR 055008 DI 10.1103/PhysRevD.62.055008 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500076 ER PT J AU Cullen, S Perelstein, M Peskin, ME AF Cullen, S Perelstein, M Peskin, ME TI TeV strings and collider probes of large extra dimensions SO PHYSICAL REVIEW D LA English DT Article ID SCALE QUANTUM-GRAVITY; E(+)E(-) COLLISIONS; BRANE WORLD; PHENOMENOLOGY; SUPERSYMMETRY; CONSTRAINTS; MILLIMETER; SIGNATURES; COUPLINGS; ORBIFOLDS AB Arkani-Hamed, Dimopoulos, and Dvali have proposed that the fundamental gravitational scale is close to 1 TeV, and that the observed weakness of gravity at long distances is explained by the presence of large extra compact dimensions. If this scenario is realized in a string theory of quantum gravity, the string excited states of standard model particles will also have TeV masses. These states will be visible to experiment and in fact provide the first signatures of the presence of a low quantum gravity scale. Their presence also affects the more familiar signatures due to real and virtual graviton emission. We study the effects of these states in a simple string model. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Stanford Univ, Dept Phys, Stanford, CA 94305 USA. NR 60 TC 204 Z9 204 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 2000 VL 62 IS 5 AR 055012 DI 10.1103/PhysRevD.62.055012 PG 21 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500080 ER PT J AU Geer, S Marriner, J Martens, M Ray, RE Streets, J Wester, W Hu, M Snow, GR Armstrong, T AF Geer, S Marriner, J Martens, M Ray, RE Streets, J Wester, W Hu, M Snow, GR Armstrong, T TI Search for antiproton decay at the Fermilab Antiproton Accumulator SO PHYSICAL REVIEW D LA English DT Article ID COSMIC-RAY ANTIPROTONS; FLUX; CPT AB A search for antiproton decay has been made at the Fermilab Antiproton Accumulator. Limits are placed on 13 antiproton decay modes. The results include the first explicit experimental limits on the muonic decay modes of the antiproton, and the first limits on the decay modes e(-)gamma gamma and e(-)omega. The most stringent limit is for the decay mode (p) over bar --> e(-)gamma. At 90% C.L. we find that tau(p)(-)/B((p) over bar --> e(-)gamma) > 7 X 10(5) yr. The most stringent limit for decay modes with a muon in the final state is for the decay (p) over bar --> mu(-)gamma. At 90% C.L. we find that tau(p)(-)/B((p) over bar --> mu(-)gamma) > 5 X 10(4) yr. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Nebraska, Lincoln, NE 68588 USA. Penn State Univ, University Pk, PA 16802 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Michigan, Ann Arbor, MI 48109 USA. RP Geer, S (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 25 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 2000 VL 62 IS 5 AR 052004 DI 10.1103/PhysRevD.62.052004 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500008 ER PT J AU Isgur, N AF Isgur, N TI Critique of a pion exchange model for interquark forces SO PHYSICAL REVIEW D LA English DT Article ID ZWEIG-IIZUKA RULE; RELATIVIZED QUARK-MODEL; N-C QCD; VALENCE APPROXIMATION; CHIRAL-SYMMETRY; HADRONIC LOOPS; SPIN STRUCTURE; 1-N EXPANSION; HEAVY MESONS; GAUGE-THEORY AB I describe four serious defects of a widely discussed pion exchange model for interquark forces: it does not solve the ''spin-orbit problem'' as advertised, it fails to describe the internal structure of baryon resonances, it leads to disastrous conclusions when extended to mesons, and it is not reasonably connected to the physics of heavy-light systems. While extensions of the original pion exchange model may be able to correct these defects, this catalogue of criticisms defines some of the most formidable problems such elaborations must address. C1 Jefferson Lab, Newport News, VA 23606 USA. RP Isgur, N (reprint author), Jefferson Lab, 12000 Jefferson Ave, Newport News, VA 23606 USA. NR 76 TC 69 Z9 70 U1 0 U2 2 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 1 PY 2000 VL 62 IS 5 AR 054026 DI 10.1103/PhysRevD.62.054026 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500052 ER PT J AU Khan, AA Bhattacharya, T Collins, S Davies, CTH Gupta, R Morningstar, C Shigemitsu, J Sloan, J AF Khan, AA Bhattacharya, T Collins, S Davies, CTH Gupta, R Morningstar, C Shigemitsu, J Sloan, J TI Heavy-light mesons and baryons with b quarks SO PHYSICAL REVIEW D LA English DT Article ID STATISTICS LATTICE CALCULATION; NONRELATIVISTIC QCD; DECAY CONSTANTS; MASS-SPECTRUM; Y-SPECTRUM; SPECTROSCOPY; NRQCD; PHYSICS; RENORMALONS; BETA AB We present lattice results for the spectrum of mesons containing one heavy quark and of baryons containing one or two heavy quarks. The calculation is done in the quenched approximation using the NRQCD formalism for the heavy quark. We analyze the dependence of the mass splittings on both the heavy and the light quark masses. Meson P-state fine structure and baryon hyperfine splittings are resolved for the first time. We fix the b quark mass using both M-B and M-Lambda b, and our best estimate is m(b)(<(MS)over bar>) (m(b)(<(MS)over bar>)) = 4.35(10)((-3)(+2)) (20) Gev. The spectrum, obtained by interpolation to m(b), is compared with the experimental data. C1 Univ Tsukuba, Ctr Computat Phys, Tsukuba, Ibaraki 3058577, Japan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland. Florida Int Univ, Dept Phys, Miami, FL 33199 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Kentucky, Dept Phys, Lexington, KY 40506 USA. RP Univ Tsukuba, Ctr Computat Phys, Tsukuba, Ibaraki 3058577, Japan. RI Bhattacharya, Tanmoy/J-8956-2013 OI Bhattacharya, Tanmoy/0000-0002-1060-652X NR 50 TC 40 Z9 40 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 2000 VL 62 IS 5 AR 054505 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500060 ER PT J AU Mocioiu, I Shrock, R AF Mocioiu, I Shrock, R TI Matter effects on neutrino oscillations in long baseline experiments SO PHYSICAL REVIEW D LA English DT Article ID ZENITH-ANGLE DISTRIBUTION; SUPER-KAMIOKANDE; ATMOSPHERIC NEUTRINOS; PARAMETRIC-RESONANCE; LSND EXPERIMENT; CP VIOLATION; SOLAR; FLUX; SEARCH; RATIO AB We calculate matter effects on neutrino oscillations relevant for long baseline experiments. In particular, we compare the results obtained with constant density along the neutrino path versus results obtained by incorporating the actual density profiles in the Earth. We study the dependence of the oscillation signal on both E/Delta m(atm)(2) and on the angles in the leptonic mixing matrix. We also comment on the influence of Delta m(sol)(2) and CP violation on the oscillations. The results show quantitatively how, as a function of these input parameters, matter effects can cause significant (25%) changes in the oscillation probabilities. An important conclusion is that matter effects can be useful in amplifying certain neutrino oscillation signals and helping one to obtain measurements of mixing parameters and the magnitude and sign of Delta m(atm)(2). C1 SUNY Stony Brook, CN Yang Inst Theoret Phys, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Mocioiu, I (reprint author), SUNY Stony Brook, CN Yang Inst Theoret Phys, Stony Brook, NY 11794 USA. EM mocioiu@insti.physics.sunysb.edu; shrock@insti.physics.sunysb.edu NR 83 TC 59 Z9 59 U1 0 U2 0 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 1 PY 2000 VL 62 IS 5 AR 053017 DI 10.1103/PhysRevD.62.053017 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500026 ER PT J AU Quinn, HR SIlva, JP AF Quinn, HR SIlva, JP TI Use of early data on B -> rho pi decays SO PHYSICAL REVIEW D LA English DT Article ID CP ASYMMETRY; ISOSPIN ANALYSIS; AMBIGUITIES AB This paper reviews the Dalitz plot analysis for the decays B-0((B) over bar(0))-->rho pi-->pi(+)pi(-)pi(0). We discuss what can be learned about the ten parameters in this analysis from untagged and from tagged time-integrated data. We find that, with the important exception of the interesting CP violating quantity alpha, the parameters can be determined from this data sample-and, hence, they can be measured at CLEO as well as at the asymmetric B factories. This observation also suggests that the extraction of alpha from the time-dependent data sample can he accomplished with a smaller data sample (and, therefore, sooner) than would be required if all ten parameters were to be obtained from the well-tagged time-dependent data sample alone. We also explore bounds on the shift of the true angle alpha from the angle measured from charged rho final states alone. These may be obtained prior to measurements of the parameters describing the neutral rho channel, which are expected to be small. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Inst Super Engn Lisboa, P-1900 Lisbon, Portugal. RP Quinn, HR (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RI Silva, Joao/A-2896-2009; Physics Department, ISEL/F-6664-2010 OI Silva, Joao/0000-0002-6455-9618; NR 21 TC 45 Z9 45 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 1 PY 2000 VL 62 IS 5 AR 054002 DI 10.1103/PhysRevD.62.054002 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500028 ER PT J AU Ramsey-Musolf, MJ AF Ramsey-Musolf, MJ TI Nuclear beta decay, atomic parity violation, and new physics SO PHYSICAL REVIEW D LA English DT Article ID RADIATIVE-CORRECTIONS; BRANCHING RATIO; NONCONSERVATION; CESIUM AB The determinations of \V-ud\(2) with super-allowed Fermi beta decay in nuclei and of the weak charge of cesium in atomic parity violation deviate from the standard model predicitions by 2 sigma or more. In both cases, the standard model overpredicts the magnitudes of the relevant observables. I discuss the implications of these results for R-parity violating (RPV) extensions of the minimal supersymmetric standard model. I also explore the possible consequences for RPV supersymmetry of prospective future low-energy electroweak measurements. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Thomas Jefferson Natl Accelerator Facil, Theory Grp, Newport News, VA 23606 USA. RP Ramsey-Musolf, MJ (reprint author), Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. NR 28 TC 23 Z9 23 U1 0 U2 2 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 1 PY 2000 VL 62 IS 5 AR 056009 DI 10.1103/PhysRevD.62.056009 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500091 ER PT J AU Rischke, DH AF Rischke, DH TI Debye screening and the Meissner effect in a three-flavor color superconductor SO PHYSICAL REVIEW D LA English DT Article ID FINITE BARYON DENSITY; QUARK MATTER; QCD; SUPERFLUIDITY; INSTANTONS; LOCKING AB I compute the gluon self-energy in a color superconductor with three flavors of massless quarks, where condensation of Cooper pairs breaks the color and flavor SU(3)(c) x U(3)(V) x U(3)(A) symmetry of QCD to the diagonal subgroup SU(3)(c+V). At zero temperature, all eight electric gluons obtain a Debye screening mass, and all eight magnetic gluons a Meissner mass. The Debye as well as the Meissner masses are found to he equal for the different gluon colors. These masses determine the coefficients of the kinetic terms in the effective theory for the low-energy degrees of freedom. Their values agree with those obtained by Son and Stephanov. C1 Brookhaven Natl Lab, BNL Res Ctr, RIKEN, Upton, NY 11973 USA. RP Brookhaven Natl Lab, BNL Res Ctr, RIKEN, Upton, NY 11973 USA. EM rischke@bnl.gov NR 78 TC 80 Z9 82 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 2000 VL 62 IS 5 AR 054017 DI 10.1103/PhysRevD.62.054017 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500043 ER PT J AU Wu, GH Soni, A AF Wu, GH Soni, A TI Novel CP-violating effects in B decays from a charged Higgs boson in a two-Higgs-doublet model for the top quark SO PHYSICAL REVIEW D LA English DT Article ID CHANGING NEUTRAL CURRENTS; STANDARD MODEL; 2-HIGGS-DOUBLET MODEL; SYMMETRY-BREAKING; PHYSICS; MATRIX; B->PSI-K-S; TOPCOLOR; SCALARS; GAMMA AB We explore charged-Higgs CP-violating effects in a specific type III two-Higgs-doublet model which is theoretically attractive as it accommodates the large mass of the top quark in a natural fashion. Two new CP-violating phases arise from the right-handed up quark sector. We consider CP violation in both neutral and charged B decays. Some of the important findings are as follows. (1) Large direct-CP asymmetry is found to be possible for B+/--->psi/JK(+/-). (2) A sizable D (D) over bar mixing effect at the percent level is found to be admissible despite the stringent constraints from the data on K (K) over bar mixing, b --> s gamma and B- --> tau<(nu)over bar> decays. (3) A simple but distinctive CP asymmetry pattern emerges in decays of B-d and B-s masons, including B-d --> psi/J K-S, D+D-, and B-s --> Ds+Ds-, psi eta/eta', psi/J K-S. (4) The effect of D (D) over bar mixing on the CP asymmetry in B+/- --> D/(D) over bar K+/- and on the extraction of the angle gamma of the unitarity triangle from such decays can be significant. C1 Univ Oregon, Inst Theoret Sci, Eugene, OR 97403 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Univ Oregon, Inst Theoret Sci, Eugene, OR 97403 USA. EM wu@dirac.uoregon.edu; soni@bnl.gov NR 46 TC 32 Z9 33 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 2000 VL 62 IS 5 AR 056005 DI 10.1103/PhysRevD.62.056005 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 349AW UT WOS:000089022500087 ER PT J AU Wallace, DC AF Wallace, DC TI Theory of stress fluctuations SO PHYSICAL REVIEW E LA English DT Article ID LIQUID DYNAMICS THEORY; MOLECULAR-DYNAMICS; ELASTIC-CONSTANTS; ENSEMBLE AB The current status of the theory of stress fluctuations is marked by two circumstances: no currently available formulas are valid for a metallic system, and a series of contradictory formulas remains unresolved. Here we derive formulas for shear- and isotropic-stress energy fluctuations, in the primary statistical mechanics ensembles. These formulas are valid for a classical monatomic system representing a metal or nonmetal, in cubic crystal, amorphous solid, or liquid phases. Current contradictions in fluctuation formulas are resolved through the following observations. First, the expansion of a dynamical variable A in terms of the fluctuations explicit in a given ensemble distribution, for example delta A=a delta N+b delta H in the grand canonical ensemble, is correct if and only if delta A is a function only of delta N and delta H. The common use of this expansion has produced incorrect fluctuation formulas. Second, the thermodynamic fluctuations of Landau and Lifshitz do not correspond to statistical mechanics fluctuations, and the two types of fluctuations have essentially different values. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Wallace, DC (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 25 TC 3 Z9 3 U1 3 U2 6 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 2000 VL 62 IS 3 BP 3077 EP 3082 DI 10.1103/PhysRevE.62.3077 PN A PG 6 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 356MK UT WOS:000089446900016 ER PT J AU Sanchez, A Bishop, AR Moro, E AF Sanchez, A Bishop, AR Moro, E TI Roughening and super-roughening in the ordered and random two-dimensional sine-Gordon models SO PHYSICAL REVIEW E LA English DT Article ID GROUND-STATE PROPERTIES; DISORDERED-SUBSTRATE; CRYSTALLINE SURFACE; EQUILIBRIUM BEHAVIOR; PARTICLE DEPOSITION; PHASE-TRANSITIONS; DYNAMICS; ROUGHNESS; SYSTEMS; GROWTH AB We present a comparative numerical study of the ordered and the random two-dimensional sine-Gordon models on a lattice. We analytically compute the main features of the expected high-temperature phase of both models, described by the Edwards-Wilkinson equation. We then use those results to locate the transition temperatures of both models in our Langevin dynamics simulations. We show that our results reconcile previous contradictory numerical works concerning the super-roughening transition in the random sine-Gordon model. We also find evidence supporting the existence of two different low-temperature phases for the disordered model. We discuss our results in view of the different analytical predictions available and comment on the nature of these two putative phases. C1 Univ Carlos III Madrid, Dept Matemat, GISC, Madrid 28911, Spain. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Oxford, Dept Theoret Phys, Oxford OX1 3NP, England. RP Sanchez, A (reprint author), Univ Carlos III Madrid, Dept Matemat, GISC, Ave Univ 30, Madrid 28911, Spain. RI Sanchez, Angel/A-9229-2008; OI Sanchez, Angel/0000-0003-1874-2881; MORO, ESTEBAN/0000-0003-2894-1024 NR 54 TC 12 Z9 12 U1 0 U2 0 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 2000 VL 62 IS 3 BP 3219 EP 3229 DI 10.1103/PhysRevE.62.3219 PN A PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 356MK UT WOS:000089446900033 ER PT J AU Lin, AL Hagberg, A Ardelea, A Bertram, M Swinney, HL Meron, E AF Lin, AL Hagberg, A Ardelea, A Bertram, M Swinney, HL Meron, E TI Four-phase patterns in forced oscillatory systems SO PHYSICAL REVIEW E LA English DT Article ID REACTION-DIFFUSION-SYSTEMS; FRONT BIFURCATIONS; COMPLEX PATTERNS; LIQUID-CRYSTAL; TURBULENCE AB We investigate pattern formation in self-oscillating systems forced by an external periodic perturbation. Experimental observations and numerical studies of reaction-diffusion systems and an analysis of an amplitude equation are presented. The oscillations in each of these systems entrain to rational multiples of the perturbation frequency for certain values of the forcing frequency and amplitude. We focus on the subharmonic resonant case where the system locks at one-fourth the driving frequency, and four-phase rotating spiral patterns are observed at low forcing amplitudes. The spiral patterns are studied using an amplitude equation for periodically forced oscillating systems. The analysis predicts a bifurcation (with increasing forcing) from rotating four-phase spirals to standing two-phase patterns. This bifurcation is also found in periodically forced reaction-diffusion equations, the FitzHugh-Nagumo and Brusselator models, even far from the onset of oscillations where the amplitude equation analysis is not strictly valid. In a Belousov-Zhabotinsky chemical system periodically forced with light we also observe four-phase rotating spiral wave patterns. However, we have not observed the transition to standing two-phase patterns, possibly because with increasing light intensity the reaction kinetics become excitable rather than oscillatory. C1 Univ Texas, Ctr Nonlinear Dynam, Austin, TX 78712 USA. Univ Texas, Dept Phys, Austin, TX 78712 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Theoret Div T7, Los Alamos, NM 87545 USA. Univ Texas, CFD Lab, Austin, TX 78712 USA. Univ Texas, ASE ME Dept, Austin, TX 78712 USA. Ben Gurion Univ Negev, BIDR, Dept Energy & Environm Phys, IL-84990 Sede Boqer, Israel. RP Lin, AL (reprint author), Univ Texas, Ctr Nonlinear Dynam, Austin, TX 78712 USA. RI MERON, EHUD/F-1810-2012 NR 26 TC 73 Z9 73 U1 0 U2 9 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 2000 VL 62 IS 3 BP 3790 EP 3798 DI 10.1103/PhysRevE.62.3790 PN B PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 356ML UT WOS:000089447000014 ER PT J AU Bardenhagen, SG Brackbill, JU Sulsky, D AF Bardenhagen, SG Brackbill, JU Sulsky, D TI Numerical study of stress distribution in sheared granular material in two dimensions SO PHYSICAL REVIEW E LA English DT Article ID DISTINCT ELEMENT METHOD; FORCE FLUCTUATIONS; BEAD PACKS; MODEL; SIMULATIONS; KINEMATICS; MECHANICS; FLOWS; MEDIA; SAND AB We simulate the response of dense granular material to shear. Our simulations use a micromechanical model which includes realistic material models for each deformable grain, and a Coulomb friction model for interactions between grains. We measure the probability density function (PDF) governing the volume distribution of stress for monodisperse and polydisperse samples, circular and polygonal grains, and various values of microscopic friction coefficients, yield stresses, and packing fractions. Remarkably, PDF's are similar in form for all cases simulated, and similar to those observed in experiments with granular materials under both compression and shear. Namely, the simulations yield an exponential probability of large stresses above the mean. The relationship between distributions of boundary tractions and volume distributions of stress is discussed. The ratio of normal and tangential components of traction on the boundary defines a bulk frictional response, which is shown to increase with the intergranular friction coefficient. However, the bulk friction is always larger than the intergranular friction for densely packed samples. Bulk friction is also strongly dependent on grain size distribution and shape. New observations of force-chain banding during recrystallization, of slip systems in monodisperse samples, and of the effects of plastic yield, are also presented. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ New Mexico, Albuquerque, NM 87131 USA. RP Bardenhagen, SG (reprint author), Univ Utah, Dept Mech Engn, Salt Lake City, UT 84112 USA. NR 28 TC 47 Z9 47 U1 0 U2 12 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 2000 VL 62 IS 3 BP 3882 EP 3890 DI 10.1103/PhysRevE.62.3882 PN B PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 356ML UT WOS:000089447000026 ER PT J AU Murillo, MS AF Murillo, MS TI Viscosity estimates for strongly coupled Yukawa systems SO PHYSICAL REVIEW E LA English DT Article ID ONE-COMPONENT PLASMA; THERMONUCLEAR REACTION-RATES; THERMODYNAMIC PROPERTIES; MIXTURES AB An analytic form for the shear viscosity of a Yukawa system, in terms of the known result for the one-component plasma, is given by establishing an analytic correspondence between the Yukawa and one-component plasma systems. The correspondence is found by ensuring that the Yukawa system and the reference one-component plasma have identical effective hard-sphere packing fractions, as determined by the Gibbs-Bogolyubov inequality. The resulting prediction for the freezing transition is compared with known simulation results. These results are useful for describing dynamical properties of Yukawa systems, and the method can be easily generalized to mixtures. C1 Univ Calif Los Alamos Natl Lab, Div Appl Phys, Plasma Phys Grp, Los Alamos, NM 87545 USA. RP Murillo, MS (reprint author), Univ Calif Los Alamos Natl Lab, Div Appl Phys, Plasma Phys Grp, MS B259, Los Alamos, NM 87545 USA. NR 23 TC 19 Z9 19 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD SEP PY 2000 VL 62 IS 3 BP 4115 EP 4119 DI 10.1103/PhysRevE.62.4115 PN B PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 356ML UT WOS:000089447000056 ER PT J AU Orion, I Rosenfeld, AB Dilmanian, FA Telang, F Ren, B Namito, Y AF Orion, I Rosenfeld, AB Dilmanian, FA Telang, F Ren, B Namito, Y TI Monte Carlo simulation of dose distributions from a synchrotron-produced microplanar beam array using the EGS4 code system SO PHYSICS IN MEDICINE AND BIOLOGY LA English DT Article ID X-RAYS; SCATTERING; WIGGLER; PHOTON AB Microbeam therapy is established as a general concept for brain tumour treatment. A synchrotron based x-ray source was chosen for experimental research into microbeam therapy, and therefore new simulations were essential for investigating the therapy parameters with a proper description of the synchrotron radiation characteristics. To design therapy parameters for tumour treatments, the newly upgraded LSCAT (Low energy SCATtering) package of the EGS4 Monte Carlo simulation code was adapted to develop an accurate self-written user code for calculating microbeam radiation dose profiles with a precision of 1 mu m LSCAT is highly suited to this purpose due to its ability to simulate low-energy x-ray transport with detailed photon interactions (including bound electron incoherent scattering functions, and linear polarized coherent scattering). The properties of the synchrotron x-ray microbeam, including its polarization, source spectrum and beam penumbra, were simulated by the new user codes. Two concentric spheres, an inner sphere, defined as a brain, and a surrounding sphere, defined as a skull, represented the phantom. The microbeam simulation was tested using a 3 x 3 cm array beam for small treatment areas and a 6 x 6 cm array for larger ones, with different therapy parameters, such as beam width and spacing. The results showed that the microbeam array retained an adequate peak-to-valley ratio, of five times at least, at tissue depths suitable for radiation therapy. Dose measurements taken at 1 mu m resolution with an 'edge-on' MOSFET validated the basics of the user code for microplanar radiation therapy. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Univ Wollongong, Dept Phys, Wollongong, NSW 2500, Australia. Kek Nat Lab High Energy Phys, Tsukuba, Ibaraki 305, Japan. RP Orion, I (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RI ORION, ITZHAK/F-2034-2012; Rosenfeld, Anatoly/D-1989-2014 NR 22 TC 34 Z9 35 U1 3 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0031-9155 J9 PHYS MED BIOL JI Phys. Med. Biol. PD SEP PY 2000 VL 45 IS 9 BP 2497 EP 2508 DI 10.1088/0031-9155/45/9/304 PG 12 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Radiology, Nuclear Medicine & Medical Imaging GA 356HY UT WOS:000089438900008 PM 11008951 ER PT J AU Vataga, ES Murzin, VS Aderholz, M Ammosov, VV Asratian, AS Barth, M Bingham, HH Brucker, EB Burnstein, RA Chatterjee, TK Clayton, EC Ermolov, PF Erofeeva, IN Faulkner, PJW Gapienko, GS Guy, J Hanlon, J Harigel, G Ivanilov, AA Jain, V Jones, GT Jones, MD Kafka, T Kaftanov, VS Kalelkar, M Kohli, JM Korablev, VA Kubantsev, MA Lauko, M Lukina, OY Lys, J Lyutov, SI Marage, P Milburn, RH Mittra, IS Morrison, DRO Moskalev, VI Myatt, G Naon, R Passmore, D Peters, MW Rubin, H Sacton, J Schneps, J Singh, JB Singh, S Smart, W Smirnova, LN Stamer, P Varvell, KE Venus, W Willocq, S AF Vataga, ES Murzin, VS Aderholz, M Ammosov, VV Asratian, AS Barth, M Bingham, HH Brucker, EB Burnstein, RA Chatterjee, TK Clayton, EC Ermolov, PF Erofeeva, IN Faulkner, PJW Gapienko, GS Guy, J Hanlon, J Harigel, G Ivanilov, AA Jain, V Jones, GT Jones, MD Kafka, T Kaftanov, VS Kalelkar, M Kohli, JM Korablev, VA Kubantsev, MA Lauko, M Lukina, OY Lys, J Lyutov, SI Marage, P Milburn, RH Mittra, IS Morrison, DRO Moskalev, VI Myatt, G Naon, R Passmore, D Peters, MW Rubin, H Sacton, J Schneps, J Singh, JB Singh, S Smart, W Smirnova, LN Stamer, P Varvell, KE Venus, W Willocq, S CA E632 Collaboration TI Intranuclear cascade in the interactions of neutrinos with neon nuclei SO PHYSICS OF ATOMIC NUCLEI LA English DT Article ID CHARGED-CURRENT INTERACTIONS; MULTIPLICITY DISTRIBUTIONS; HADRONS; LEPTOPRODUCTION; FRAGMENTATION; COLLISIONS; TARGETS; MODEL; AU AB A method is developed for separating nu N interactions from interactions involving an intranuclear cascade in nu Ne scattering at a mean neutrino energy of 145 GeV. The fraction of events featuring a cascade is evaluated by using a sample of nu Ne charged-current interactions, It is found that the multiplicity of charged particles in the forward direction takes the same value for events with and without a cascade for 4 < W-2 < 550 GeV2. In the backward direction, cascade events have the charge multiplicity higher than the multiplicity for cascade-free events by 2.36 units. It is found that particles with momenta less than 2 GeV/c make a dominant contribution to the rescattering process. A depletion of the fastest particles for W-2 < 50 GeV2 is observed, in accord with the formation-time concept. (C) 2000 MAIK "Nauka/Interperiodica". C1 Moscow MV Lomonosov State Univ, Moscow 119899, Russia. Max Planck Inst Phys, D-80805 Munich, Germany. Inst High Energy Phys, Protvino 142284, Moscow Oblast, Russia. Inst Theoret & Expt Phys, Moscow 117259, Russia. USB VUB, Interuniv Inst High Energies, B-1050 Brussels, Belgium. Univ Calif Berkeley, Berkeley, CA 94720 USA. Stevens Inst Technol, Hoboken, NJ 07030 USA. IIT, Chicago, IL 60616 USA. Panjab Univ, Chandigarh 160014, India. Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Fermilab, Batavia, IL 60510 USA. CERN, CH-1211 Geneva, Switzerland. Univ Hawaii, Honolulu, HI 96822 USA. Tufts Univ, Medford, MA 02155 USA. Rutgers State Univ, Piscataway, NJ USA. Univ Oxford, Dept Nucl Phys, Oxford OX1 3RH, England. RP Vataga, ES (reprint author), Moscow MV Lomonosov State Univ, Moscow 119899, Russia. RI Smirnova, Lidia/D-8089-2012 NR 26 TC 4 Z9 4 U1 0 U2 0 PU MAIK NAUKA/INTERPERIODICA PUBL PI MELVILLE PA C/O AMERICAN INST PHYSICS, 2 HUNTINGTON QUANDRANGLE, STE 1NO1, MELVILLE, NY 11747-4502 USA SN 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD SEP PY 2000 VL 63 IS 9 BP 1574 EP 1583 DI 10.1134/1.1312890 PG 10 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 362LV UT WOS:000089780200010 ER PT J AU Barenblatt, GI Chorin, AJ Prostokishin, VM AF Barenblatt, GI Chorin, AJ Prostokishin, VM TI A note on the intermediate region in turbulent boundary layers SO PHYSICS OF FLUIDS LA English DT Article AB We demonstrate that the processing of the experimental data for the average velocity profiles obtained by J. M. Osterlund presented in Phys. Fluids 12, 1-4 (2000) was incorrect. Properly processed these data lead to the opposite conclusion: They confirm the Reynolds-number-dependent scaling law and disprove the conclusion that the flow in the intermediate ("overlap") region is Reynolds-number-independent. (C) 2000 American Institute of Physics. [S1070-6631(00)01009-6]. C1 Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Russian Acad Sci, PP Shirshov Oceanol Inst, Moscow 117218, Russia. RP Barenblatt, GI (reprint author), Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. OI Prostokishin, Valeriy/0000-0001-6185-9642 NR 4 TC 23 Z9 23 U1 0 U2 2 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 2000 VL 12 IS 9 BP 2159 EP 2161 DI 10.1063/1.1287613 PG 3 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 344YP UT WOS:000088788900002 ER PT J AU Chu, TK AF Chu, TK TI Turbulent steady-state configuration of an inductively driven, dissipative tokamak plasma SO PHYSICS OF PLASMAS LA English DT Article ID MACROTOR TOKAMAK; TOROIDAL PLASMA; FLUCTUATIONS; PROFILE AB By taking Faraday's equation into account and using a variational principle that optimizes dissipation, it is shown that the turbulent steady-state profile of current density of an inductively driven tokamak plasma is peaked at the axis and decreases monotonically to a finite value at the edge. It corresponds to a state of minimum rate of dissipation of poloidal magnetic field energy under the constraint that all tearing points on its rational surfaces are equally effective in reducing the slope of the current density across the surface. An alternative interpretation is that the configuration corresponds to a state of maximum poloidal magnetic field energy for the prescribed plasma current. (C) 2000 American Institute of Physics. [S1070-664X(00)01509-3]. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Chu, TK (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 25 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD SEP PY 2000 VL 7 IS 9 BP 3537 EP 3541 AR PII [S1070-664X(00)01509-3] DI 10.1063/1.1287135 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 345BC UT WOS:000088794700007 ER PT J AU Porter, GD Isler, R Boedo, J Rognlien, TD AF Porter, GD Isler, R Boedo, J Rognlien, TD TI Detailed comparison of simulated and measured plasma profiles in the scrape-off layer and edge plasma of DIII-D SO PHYSICS OF PLASMAS LA English DT Article ID DIVERTOR PLASMAS; CONVECTION; PARAMETERS; GRAPHITE; EROSION; FLOWS; ION AB The results of detailed comparisons between experimental measurements of the scrape-off layer and divertor plasmas and simulations using the UEDGE code for a DIII-D discharge [J. Luxon , Proceedings of the 11th International Conference on Plasma Physics and Controlled Nuclear Fusion (International Atomic Energy Agency, Vienna, 1986), Vol. I, p. 159] are reported. The simulations focus on understanding the flow of both fuel and impurity particles throughout the edge and scrape-off layer (SOL) plasma. The core impurity content and the core hydrogen ionization rate can be explained by sputtering and recycling in the divertor region alone. The model reproduces most of the detailed experimental measurements. The simulations include the effect of intrinsic impurities, assumed to be carbon originating from sputtering of the plasma facing surfaces. The simulations accurately reproduce the total radiated power, although the spatial profile of radiation is somewhat narrower in the simulation. The measured carbon density on closed field lines is reproduced well with the simulation. Comparison of carbon emission lines indicates the total carbon sputtering yield is a factor of 2 to 4 less than expected, although the total radiated power and core carbon content are insensitive to the sputtering yield. The agreement between simulation and experiment permits more meaningful interpretation of the experimental measurements. (C) 2000 American Institute of Physics. [S1070-664X(00)02708-7]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Porter, GD (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-637,POB 808, Livermore, CA 94551 USA. OI Isler, Ralph/0000-0002-5368-7200 NR 31 TC 35 Z9 35 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD SEP PY 2000 VL 7 IS 9 BP 3663 EP 3680 DI 10.1063/1.1286509 PG 18 WC Physics, Fluids & Plasmas SC Physics GA 345BC UT WOS:000088794700020 ER PT J AU Zaslavsky, GM Edelman, M Weitzner, H Carreras, B McKee, G Bravenec, R Fonck, R AF Zaslavsky, GM Edelman, M Weitzner, H Carreras, B McKee, G Bravenec, R Fonck, R TI Large-scale behavior of the tokamak density fluctuations SO PHYSICS OF PLASMAS LA English DT Article ID SELF-ORGANIZED CRITICALITY; TURBULENT TRANSPORT; PLASMA EDGE; DYNAMICS; SIMILARITY; PARADIGM; CHAOS AB An analysis of tokamak density fluctuations data permits the determination of two characteristic exponents. The exponents correspond to the powers of a power-law dependence of the distributions of the long-lasting monotonic change ("flight") of the density and the time length of these changes. Speculation based on these results leads to construction of the fractional kinetic equation for the distribution function of the flights. The asymptotic transport properties of the particle density distribution function are directly connected with the exponents obtained from the density fluctuations data. (C) 2000 American Institute of Physics. [S1070-664X(00)04008-8]. C1 NYU, Courant Inst Math Sci, New York, NY 10012 USA. NYU, Dept Phys, New York, NY 10003 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Wisconsin Gen Atom, San Diego, CA 92186 USA. Univ Texas, Austin, TX 78712 USA. RP NYU, Courant Inst Math Sci, 251 Mercer St, New York, NY 10012 USA. NR 32 TC 43 Z9 43 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD SEP PY 2000 VL 7 IS 9 BP 3691 EP 3698 AR PII [S1070-664X(00)04008-8] DI 10.1063/1.1286669 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 345BC UT WOS:000088794700022 ER PT J AU Fernandez, JC Cobble, JA Montgomery, DS Wilke, MD Afeyan, BB AF Fernandez, JC Cobble, JA Montgomery, DS Wilke, MD Afeyan, BB TI Observed insensitivity of stimulated Raman scattering on electron density SO PHYSICS OF PLASMAS LA English DT Article ID LASER HOT-SPOTS; INERTIAL CONFINEMENT FUSION; NATIONAL-IGNITION-FACILITY; BRILLOUIN-SCATTERING; PARAMETRIC-INSTABILITIES; HOHLRAUM PLASMAS; SATURATION; TURBULENCE; DEPENDENCE; SPECTRUM AB The results from experiments in quasihomogeneous plasmas to evaluate the potential threat of high laser reflectivity from stimulated Raman scattering (SRS) to inertial-confinement fusion (ICF) are presented. The SRS laser reflectivity is observed to be sizable (up to 50%) and very weakly dependent on electron density (and k lambda(D)), over a large range of density that corresponds to a large variation in Landau damping of plasma waves. In contrast, the reflectivity increases monotonically over time, along with ion temperature, until gross hydrodynamic activity interferes with SRS. This is consistent with previous observations of SRS reflectivity scaling with the damping rate of ion acoustic waves [Fernandez , Phys. Rev. Lett. 77, 2702 (1996); Kirkwood , ibid. 77, 2706 (1996)]. The data from plasmas with the highest k lambda(D) values indicate anomalously low damping rates for the SRS plasma wave. (C) 2000 American Institute of Physics. [S1070-664X(00)01409-9]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Polymath Res Inc, Pleasanton, CA USA. RP Fernandez, JC (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Fernandez, Juan/H-3268-2011; OI Fernandez, Juan/0000-0002-1438-1815; Montgomery, David/0000-0002-2355-6242 NR 43 TC 39 Z9 40 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD SEP PY 2000 VL 7 IS 9 BP 3743 EP 3750 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 345BC UT WOS:000088794700029 ER PT J AU Fuchs, CA Peres, A AF Fuchs, CA Peres, A TI Quantum theory - Interpretation, formulation, inspiration - Reply SO PHYSICS TODAY LA English DT Letter C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Technion Israel Inst Technol, Haifa, Israel. RP Fuchs, CA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 2 TC 9 Z9 9 U1 3 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD SEP PY 2000 VL 53 IS 9 BP 14 EP + PG 2 WC Physics, Multidisciplinary SC Physics GA 348JZ UT WOS:000088982900006 ER PT J AU Johnson, JL Greene, JM AF Johnson, JL Greene, JM TI Katherine Ella Mounce Weimer - Obituary SO PHYSICS TODAY LA English DT Biographical-Item C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Gen Atom Co, San Diego, CA USA. RP Johnson, JL (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD SEP PY 2000 VL 53 IS 9 BP 88 EP 88 DI 10.1063/1.1325250 PG 1 WC Physics, Multidisciplinary SC Physics GA 348JZ UT WOS:000088982900024 ER PT J AU Hidema, J Kumagai, T Sutherland, BM AF Hidema, J Kumagai, T Sutherland, BM TI UV radiation-sensitive Norin 1 rice contains defective cyclobutane pyrimidine dimer photolyase SO PLANT CELL LA English DT Article ID ULTRAVIOLET-B RADIATION; ORYZA-SATIVA L; DNA-DAMAGE; CUCUMBER COTYLEDONS; ALFALFA SEEDLINGS; AMBIENT LEVELS; STRAND BREAKS; REPAIR; GROWTH; ARABIDOPSIS AB Norin 1, a progenitor of many economically important Japanese rice strains, is highly sensitive to the damaging effects of UVB radiation (wavelengths 290 to 320 nm). Norin 1 seedlings are deficient in photorepair of cyclobutane pyrimidine dimers. However, the molecular origin of this deficiency was not known and, because rice photolyase genes have not been cloned and sequenced, could not be determined by examining photolyase structural genes or upstream regulatory elements for mutations. We therefore used a photoflash approach, which showed that the deficiency in photorepair in vivo resulted from a functionally altered photolyase. These results were confirmed by studies with extracts, which showed that the Norin 1 photolyase-dimer complex was highly thermolabile relative to the wild-type Sasanishiki photolyase. This deficiency results from a structure/function alteration of photolyase rather than of nonspecific repair, photolytic, or regulatory elements. Thus, the molecular origin of this plant DNA repair deficiency, resulting from a spontaneously occurring mutation to UV radiation sensitivity, is defective photolyase. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Tohoku Univ, Inst Genet Ecol, Sendai, Miyagi 9808577, Japan. RP Sutherland, BM (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 45 TC 54 Z9 61 U1 0 U2 2 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA SN 1040-4651 J9 PLANT CELL JI Plant Cell PD SEP PY 2000 VL 12 IS 9 BP 1569 EP 1578 DI 10.1105/tpc.12.9.1569 PG 10 WC Biochemistry & Molecular Biology; Plant Sciences; Cell Biology SC Biochemistry & Molecular Biology; Plant Sciences; Cell Biology GA 363JH UT WOS:000089832200006 PM 11006332 ER PT J AU Williamson, RL Fincke, JR Chang, CH AF Williamson, RL Fincke, JR Chang, CH TI A computational examination of the sources of statistical variance in particle parameters during thermal plasma spraying SO PLASMA CHEMISTRY AND PLASMA PROCESSING LA English DT Article DE plasma spraying; computational model; plasma jet; particle injection ID COATINGS; GENERATION; MODEL; JET; GAS AB Computational modeling is used to systematically examine many of the sources of statistical variance in particle parameters during thermal plasma spraying. Using the computer program LAVA, a steady-state plasma jet typical of a commercial touch at normal operating conditions. is first developed. Then, assuming a single particle composition (ZrO2) and injection location, veal world complexity (e.g., turbulent dispersion, particle size and density, injection velocity and direction) is introduced "one phenomenon at a time" to distinguish and characterize its effect and enable comparisons of separate effects. Calculations are also performed wherein all phenomena are considered simultaneously to enable further comparisons. Both nonswirling and swirling plasma flow firm's are considered. Investigating each phenomenon separately provides valuable insight into particle behavior. For the typical plasma jet and injection conditions considered particle dispersion in the injection direction is most significantly affected by (in order of decreasing importance). particle size distribution, injection velocity distribution, turbulence, and injection direction distribution or particle density distribution. Only the distribution of injection directions and turbulence affect dispersion normal to the injection direction and are of similar magnitude in this study. With regards to particle velocity and temperature, particle size is clearly the dominant effect. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Univ New Mexico, Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Williamson, RL (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. OI Williamson, Richard/0000-0001-7734-3632 NR 18 TC 31 Z9 35 U1 1 U2 4 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 2000 VL 20 IS 3 BP 299 EP 324 DI 10.1023/A:1007088110319 PG 26 WC Engineering, Chemical; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA 354AX UT WOS:000089308600002 ER PT J AU Hahn, YB Hays, DC Cho, H Jung, KB Lambers, ES Abernathy, CR Pearton, SJ Hobson, WS Shul, RJ AF Hahn, YB Hays, DC Cho, H Jung, KB Lambers, ES Abernathy, CR Pearton, SJ Hobson, WS Shul, RJ TI Inductively coupled plasma etching in ICl- and IBr-based chemistries. Part I: GaAs, GaSb, and AlGaAs SO PLASMA CHEMISTRY AND PLASMA PROCESSING LA English DT Article DE ICP; compound semiconductors; interhalogens ID GAN; SEMICONDUCTORS; MIXTURE; SYSTEM; DAMAGE; ALN AB High-density plasma etching of GaAs, GaSb, and AlGaAs was performed in ICl/Ar and IBr/AI chemistries using an Inductively Coupled Plasma (ICP) source. GaSb and AlGaAs showed maxima in their etch rates for both plama chemistries as a function of interhalogen percentage, while GaAs showed increased etch rates with plasma composition in both chemistries. Etch rates of all materials increased substantially with increasing rf chuck power, but rapidly decreased with chamber pressure. Selectivities > 10 for GaAs and GaSb over AlGaAs were obtained in both chemistries. The etched surfaces of GaAs showed smooth morphology which were somewhat better with ICl/Ar than with IBr/Ar discharge. Auger Electron Spectroscopy analysis revealed equirate of removal of group III and V components or the corresponding etch products, maintaining the stoichiometry of the etched surface. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hahn, YB (reprint author), Chonbuk Natl Univ, Sch Chem Engn & Technol, Chonju 561756, South Korea. NR 20 TC 3 Z9 3 U1 1 U2 4 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 2000 VL 20 IS 3 BP 405 EP 415 DI 10.1023/A:1007000613045 PG 11 WC Engineering, Chemical; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA 354AX UT WOS:000089308600008 ER PT J AU Hahn, YB Hays, DC Cho, H Jung, KB Lambers, ES Abernathy, CR Pearton, SJ Hobson, WS Shul, RJ AF Hahn, YB Hays, DC Cho, H Jung, KB Lambers, ES Abernathy, CR Pearton, SJ Hobson, WS Shul, RJ TI Inductively coupled plasma etching in ICl- and IBr-based chemistries. Part II: InP, InSb, InGaP, and InGaAs SO PLASMA CHEMISTRY AND PLASMA PROCESSING LA English DT Article DE ICP; compound semiconductors; interhalogens ID MODULATED ION-BEAM; GAAS; CL2; TEMPERATURE; DEPENDENCE; MECHANISM; MIXTURES; CHLORINE; HYDROGEN; SMOOTH AB A parametric study of Inductively Coupled Plasma (ICP) etching of InP, InSb, InGaP, and InGaAs has been carried out in ICL/Ar and IBr/Ar chemistries. Etch rater in excess of 3.1 for InP, 3.6 for InSb, 2.3 for InGaP, and 2.2 mu m/min for InGaAs were obtained in Ibr/Ar plasmas. The ICP etching of In-based materials showed a general tendency: The etch rates increased substantially with increasing ICP source power and rf chuck power in both chemistries, while they decreased with increasing chamber pressure. The IBr/Ar chemistry typically showed higher etch rates than Icl/Ar, but the etched surface morphologies were fairly poor for both chemistries. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hahn, YB (reprint author), Chonbuk Natl Univ, Sch Chem Engn & Technol, Chonju 561756, South Korea. RI Schaff, William/B-5839-2009 NR 25 TC 2 Z9 4 U1 1 U2 1 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 2000 VL 20 IS 3 BP 417 EP 427 DI 10.1023/A:1007052629883 PG 11 WC Engineering, Chemical; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA 354AX UT WOS:000089308600009 ER PT J AU Peterson, RL AF Peterson, RL TI Savannah River can relate SO POLLUTION ENGINEERING LA English DT Letter C1 US DOE, SR, OEP, EQMD, Aiken, SC USA. RP Peterson, RL (reprint author), US DOE, SR, OEP, EQMD, Aiken, SC USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CAHNERS-DENVER PUBLISHING CO PI OAK BROOK PA 2000 CLEARWATER DR, OAK BROOK, IL 60523-8809 USA SN 0032-3640 J9 POLLUT ENG JI Pollut. Eng. PD SEP PY 2000 VL 32 IS 9 BP 8 EP 8 PG 1 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 354DH UT WOS:000089314200005 ER PT J AU Pokkuluri, PR Cai, X Johnson, G Stevens, FJ Schiffer, M AF Pokkuluri, PR Cai, X Johnson, G Stevens, FJ Schiffer, M TI Change in dimerization mode by removal of a single unsatisfied polar residue located at the interface SO PROTEIN SCIENCE LA English DT Article DE antibody light chain; association constant; crystal structure; dimer interface; quaternary interactions ID CRYSTAL-STRUCTURE; PROTEIN; DOMAIN; CHAIN; CRYSTALLOGRAPHY; ASSOCIATION AB The importance of unsatisfied hydrogen bonding potential on protein-protein interaction was studied. Two alternate modes of dimerization (conventional and flipped form) of an immunoglobulin light chain variable domain (V-L) were previously identified. In the flipped form, interface residue G1n89 would have an unsatisfied hydrogen bonding potential. Removal of this Gin should render the flipped dimer as the more favorable quaternary form. High resolution crystallographic studies of the Q89A and Q89L mutants show, as we predicted, that these proteins indeed form flipped dimers with very similar interfaces. A small cavity is present in the Q89A mutant that is reflected in the similar to 100 times lower association constant than found for the Q89L mutant. The association constant of Q89A and Q89L proteins (4 X 10(6) M-1 and >10(8) M-1) are 10- and 1,000-fold higher than that of the wild-type protein that forms conventional dimers clearly showing the energetic reasons for the flipped dimer Formation. C1 Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Schiffer, M (reprint author), Argonne Natl Lab, Biosci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. FU NIDDK NIH HHS [DK43757] NR 20 TC 6 Z9 6 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD SEP PY 2000 VL 9 IS 9 BP 1852 EP 1855 PG 4 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 359MT UT WOS:000089615200024 PM 11045631 ER PT J AU Katoh, S Nagaoka, S WoldeGabriel, G Renne, P Snow, MG Beyene, Y Suwa, G AF Katoh, S Nagaoka, S WoldeGabriel, G Renne, P Snow, MG Beyene, Y Suwa, G TI Chronostratigraphy and correlation of the Plio-Pleistocene tephra layers of the Konso Formation, southern Main Ethiopian Rift, Ethiopia SO QUATERNARY SCIENCE REVIEWS LA English DT Article ID KOOBI FORA REGION; ABSOLUTE AGES; VALLEY; KENYA AB The Plio-Pleistocene Konso Formation is widely exposed in the Konso area located at the southwestern end of the southern sector of the Main Ethiopian Rift. It is known for its rich Acheulean archeological occurrences and abundant Vertebrate fossils, including those of A. boisei and H, erectus. The formation also contains more than 30 tephra layers. The lithologic characterization and major element compositions of discrete glass shards of these tephra, combined with single-crystal Ar-40/Ar-39 dating of seven tuffs, have established the tephrostratigraphy and age range of the 200-m thick formation. The succession at Konso was deposited between approximately 1.9 and 1.4 Ma and is divided into the Sorobo, Turoha, Kayle, and Karat Members in ascending stratigraphic order. Two of the Konso tephra are correlative to the Pliocene KBS and the early Pleistocene Chari Tuffs of the Omo-Turkana Basin along the Ethiopian and Kenyan border. This correlation enables precise time-controlled comparisons of faunal and archeological remains between the two regions. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Hyogo Museum Nat & Human Act, Div Earth Sci, Sanda, Hyogo 6691546, Japan. Nagasaki Univ, Dept Geog, Nagasaki 8528131, Japan. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Berkeley Geochronol Ctr, Berkeley, CA 94709 USA. Minist Informat & Culture, Dept Archaeol & Anthropol, CRCCH, Addis Ababa, Ethiopia. Univ Tokyo, Univ Museum, Bunkyo Ku, Tokyo 1130033, Japan. RP Katoh, S (reprint author), Hyogo Museum Nat & Human Act, Div Earth Sci, Yayoigaoka 6, Sanda, Hyogo 6691546, Japan. NR 20 TC 35 Z9 37 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0277-3791 J9 QUATERNARY SCI REV JI Quat. Sci. Rev. PD SEP PY 2000 VL 19 IS 13 BP 1305 EP 1317 DI 10.1016/S0277-3791(99)00099-2 PG 13 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 344GD UT WOS:000088750100005 ER PT J AU Miller, JH Resat, MS Metting, NF Wei, K Lynch, DJ Wilson, WE AF Miller, JH Resat, MS Metting, NF Wei, K Lynch, DJ Wilson, WE TI Monte Carlo simulation of single cell irradiation by an electron microbeam SO RADIATION AND ENVIRONMENTAL BIOPHYSICS LA English DT Article ID ALPHA-PARTICLES; LIQUID WATER; EXPRESSION; CODE AB A model is presented for irradiation of a cellular monolayer by an electron microbeam. Results are presented for two possible window designs, cells plated on the vacuum-isolation window and cells plated on Mylar above the vacuum-isolation window. Even for the thicker dual-membrane window that facilitates tissue culture and allows the target cell to be centered relative to the electron beam, the majority of the calculated beam spreading was contained in a volume typical of the mammalian HeLa cell line. None of the 104 electrons simulated at 25 keV were scattered into the spatial region occupied by neighbors of the target cell. Dose leakage was largest at 50 keV where the mean energy deposited in all neighbors was 21% of that deposited in the target cell. This ratio was reduced to 5% at 90 keV, the highest beam energy simulated. Lineal energy spectra of energy deposition events scored in the nucleus of the target cell became progressively more like the gamma-ray spectrum as the electron beam energy increased. Hence, our simulations provide strong support for the feasibility of a low-LET, single-cell irradiator. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Washington State Univ Tri Cities, Richland, WA 99352 USA. RP Miller, JH (reprint author), Pacific NW Natl Lab, POB 999,Mail Sto K1-83, Richland, WA 99352 USA. NR 14 TC 21 Z9 23 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0301-634X J9 RADIAT ENVIRON BIOPH JI Radiat. Environ. Biophys. PD SEP PY 2000 VL 39 IS 3 BP 173 EP 177 DI 10.1007/s004110000057 PG 5 WC Biology; Biophysics; Environmental Sciences; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Environmental Sciences & Ecology; Radiology, Nuclear Medicine & Medical Imaging GA 362EM UT WOS:000089765700003 PM 11095147 ER PT J AU Dingfelder, M Inokuti, M Paretzke, HG AF Dingfelder, M Inokuti, M Paretzke, HG TI Inelastic-collision cross sections of liquid water for interactions of energetic protons SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID K-SHELL IONIZATION; RAY-SCATTERING SPECTROSCOPY; STOPPING POWER; HYDROGEN-IONS; ANGULAR-DISTRIBUTIONS; ELECTRON PRODUCTION; CHARGE-TRANSFER; BETHE SURFACE; VAPOR; TARGETS AB Cross-section data for inelastic interactions of energetic protons with liquid water, for use, e.g. as input in track structure analysis, are derived for an energy range from 0.1 keV to 10 GeV. At proton kinetic energies above about 500 keV, the first Born approximation and the dielectric-response function determined earlier are used. At proton energies above several hundred MeV in particular, the Fermi-density effect is also incorporated. At energies below about 500 keV, which corresponds to a residual range of about 8.9 x 10(-6) m, cross-section values are derived semiempirically by an extensive and critical analysis of experimental and theoretical information concerning not only cross sections for individual processes such as ionisation, excitation, and charge transfer but also stopping power and other relevant quantities. Spectra of secondary electrons resulting from ionising collisions are also presented. The analysis also includes considerations of phase effects on cross sections. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 GSF, Natl Res Ctr Environm & Hlth, Inst Radiat Protect, D-85764 Neuherberg, Germany. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Dingfelder, M (reprint author), GSF, Natl Res Ctr Environm & Hlth, Inst Radiat Protect, Ingolstadter Landstr 1, D-85764 Neuherberg, Germany. EM dingfelder@gsf.de NR 76 TC 120 Z9 120 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD SEP PY 2000 VL 59 IS 3 BP 255 EP 275 DI 10.1016/S0969-806X(00)00263-2 PG 21 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 353UY UT WOS:000089294900005 ER PT J AU Slowinski, G Stanton, SA Tao, JC Miller, W McConnell, DP AF Slowinski, G Stanton, SA Tao, JC Miller, W McConnell, DP TI Acquiring external technology SO RESEARCH-TECHNOLOGY MANAGEMENT LA English DT Article ID WORK AB As no one company can create all of the technology needed to support today's complex products and sophisticated customers, technology leaders have been seeking ways to incorporate external technology into their organizations' internal technology and commercialization streams . Consequently, a study was undertaken to identify the processes and techniques that 22 companies were using to establish their internal technology needs, identify the external technology to fill those needs, evaluate the technology for its quality and robustness, access the technology through agreement, and integrate it into their internal portfolios Overall, the most successful programs were found to be those in which technology is valued by the business and where decisions to invest in technology are made by a senior-level cross-functional team. C1 Rutgers State Univ, Grad Sch Management, Newark, NJ 07102 USA. SBCi, Sunbury, OH USA. Air Prod & Chem Inc, Technol Partnerships, Allentown, PA USA. Sunoco, Technol & Dev, Marcus Hook, PA USA. Battelle Mem Inst, Columbus, OH 43201 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Slowinski, G (reprint author), Rutgers State Univ, Grad Sch Management, Newark, NJ 07102 USA. NR 10 TC 2 Z9 2 U1 0 U2 3 PU INDUSTRIAL RESEARCH INST INC PI WASHINGTON PA 1550 M ST., NW, WASHINGTON, DC 20005 USA SN 0895-6308 J9 RES TECHNOL MANAGE JI Res.-Technol. Manage. PD SEP-OCT PY 2000 VL 43 IS 5 BP 29 EP 35 PG 7 WC Business; Engineering, Industrial; Management SC Business & Economics; Engineering GA 348DX UT WOS:000088971200008 ER PT J AU Pease, DM Daniel, M Budnick, JI Rhodes, T Hammes, M Potrepka, DM Sills, K Nelson, C Heald, SM Brewe, DI Frenkel, A Grigorieva, I Antonov, A AF Pease, DM Daniel, M Budnick, JI Rhodes, T Hammes, M Potrepka, DM Sills, K Nelson, C Heald, SM Brewe, DI Frenkel, A Grigorieva, I Antonov, A TI Log spiral of revolution highly oriented pyrolytic graphite monochromator for fluorescence x-ray absorption edge fine structure SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID SILICON PHOTODIODE DETECTOR; EXAFS AB We have constructed an x-ray monochromator based on a log spiral of revolution covered with highly oriented pyrolytic graphite. Such a monochromator is used for obtaining x-ray absorption edge fine structure by the fluorescence method, and is particularly useful for measuring the fine structure of dilute element A in a concentrated matrix of element B, where B is to the left of A in the Periodic Table. Using the log spiral monochromator, we measure good Cr x-ray fine structure in an alloy of 1% Cr in a V matrix, whereas the corresponding spectrum is severely distorted by the V background if nonmonochromatized fluorescence is used. We also obtain excellent rejection of Mn fluorescence relative to Cr fluorescence in a Cr80Mn20 alloy, and can tune the monochromator such that the entire Mn step height is significantly smaller than the Cr x-ray absorption edge fine structure oscillations for this system. (C) 2000 American Institute of Physics. [S0034-6748(00)04109-5]. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Adv Fuel Res, E Hartford, CT 06118 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Illinois, Mat Res Lab, Urbana, IL 61801 USA. Optigraph Corp, Moscow 117812, Russia. RP Pease, DM (reprint author), Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. RI Frenkel, Anatoly/D-3311-2011; OI Frenkel, Anatoly/0000-0002-5451-1207; Potrepka, Daniel/0000-0002-0528-1038 NR 14 TC 12 Z9 12 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 2000 VL 71 IS 9 BP 3267 EP 3273 DI 10.1063/1.1287753 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 349GE UT WOS:000089036700004 ER PT J AU Takahashi, K Cline, JA Bartels, DM Jonah, CD AF Takahashi, K Cline, JA Bartels, DM Jonah, CD TI Design of an optical cell for pulse radiolysis of supercritical water SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB The design of a flow cell that is applicable to pulse radiolysis/transient absorption experiments on supercritical water is described. The cell is designed to minimize dead volume and prevent the accumulation of radiolytic products. It is also necessary to minimize emission and absorption of sapphire windows from high energy electron beam irradiation. To obtain an optical throughput of f/4, the inner diameter is 6 mm, and distance between windows is 25 mm. The effective optical path length is 20 mm for irradiation from the side through a thin Hastelloy wall. Belleville spring washers were used to keep a constant force on the 3 mm sapphire windows, which were sealed to the Hastelloy body with copper gaskets. An application of this cell to measurements of solvated electrons in supercritical water is demonstrated. (C) 2000 American Institute of Physics. [S0034-6748(00)04709-2]. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Hokkaido Univ, Grad Sch Engn, Div Quantum Energy Engn, Sapporo, Hokkaido 0608628, Japan. RP Bartels, DM (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Takahashi, Kenji/C-8846-2011; Takahashi, Kenji/F-4885-2014 NR 22 TC 27 Z9 27 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 2000 VL 71 IS 9 BP 3345 EP 3350 AR PII [S0034-6748(00)04709-2] DI 10.1063/1.1288258 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 349GE UT WOS:000089036700016 ER PT J AU Savin, DW Beiersdorfer, P Kahn, SM Beck, BR Brown, GV Gu, MF Liedahl, DA Scofield, JH AF Savin, DW Beiersdorfer, P Kahn, SM Beck, BR Brown, GV Gu, MF Liedahl, DA Scofield, JH TI Simulating a Maxwellian plasma using an electron beam ion trap SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID DIELECTRONIC SATELLITE SPECTRA; HELIUM-LIKE IONS; X-RAY SPECTROMETER; IMPACT EXCITATION; CROSS-SECTIONS; HE-LIKE; FE-XXV; RADIATIVE RECOMBINATION; LINE EMISSION; INNER-SHELL AB We describe a technique for producing a Maxwell-Boltzmann electron energy distribution using an electron beam ion trap (EBIT). The technique was implemented on the Lawrence Livermore EBIT to simulate Maxwellian plasmas. We discuss technical and experimental issues related to these simulations. To verify the fidelity of the quasi-Maxwellian, we have measured line emission due to dielectronic recombination (DR) and electron impact excitation (EIE) of heliumlike neon, magnesium, and argon for a range of simulated electron temperatures. The ratio of DR to EIE lines in heliumlike ions is a well understood electron temperature diagnostic. The spectroscopically inferred quasi-Maxwellian temperatures are in excellent agreement with the simulated temperatures. (C) 2000 American Institute of Physics. [S0034-6748(00)00609-2]. C1 Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. Univ Calif Lawrence Livermore Natl Lab, Dept Phys & Space Technol, Livermore, CA 94550 USA. RP Savin, DW (reprint author), Columbia Univ, Columbia Astrophys Lab, 538 W 120th St, New York, NY 10027 USA. RI Savin, Daniel/B-9576-2012 OI Savin, Daniel/0000-0002-1111-6610 NR 57 TC 25 Z9 27 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 2000 VL 71 IS 9 BP 3362 EP 3372 AR PII [S0034-6748(00)00609-2] DI 10.1063/1.1287045 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 349GE UT WOS:000089036700018 ER PT J AU Machima, P Bilek, MMM Monteiro, OR Brown, IG AF Machima, P Bilek, MMM Monteiro, OR Brown, IG TI Simple and inexpensive current-driven magnetic multipole plasma homogenizer SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID CATHODIC ARC DEPOSITION AB Magnetic multipole plasma confinement geometries employing permanent magnets are commonly used to confine laboratory plasmas and improve uniformity. Here we describe the design and operation of a particularly simple and low-cost kind of current-driven multipole system that makes use of a similar magnetic field structure but does not require permanent magnets. The magnetic field is generated by current carrying wires attached to the inside wall of a cylindrical supporting structure to provide a magnetic field resembling that of permanent multipole magnetic homogenizers. We demonstrate the use of the current-driven homogenizer to improve the uniformity of the radial density profile of a vacuum arc generated metal plasma. Our configuration of metal plasma gun, macroparticle filter, and current-driven homogenizer was used for thin film deposition, and was able to produce a relatively homogeneous film thickness profile while maintaining a deposition rate comparable to that at the peak point of the freely expanded beam at the same location. (C) 2000 American Institute of Physics. [S0034-6748(00)03909-5]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Cambridge, Dept Engn, Cambridge CB2 1PZ, England. RP Brown, IG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 18 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 2000 VL 71 IS 9 BP 3373 EP 3376 DI 10.1063/1.1287751 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 349GE UT WOS:000089036700019 ER PT J AU Depierreux, S Labaune, C Fuchs, J Baldis, HA AF Depierreux, S Labaune, C Fuchs, J Baldis, HA TI Application of Thomson scattering to identify ion acoustic waves stimulated by the Langmuir decay instability SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID LASER-PRODUCED PLASMAS; NON-LINEAR SATURATION; RAMAN-SCATTERING; 2-PLASMON DECAY; HOT-SPOTS; DENSITY AB In this article, we present how ion acoustic waves can be unambiguously identified and can be used to definitely demonstrate the existence of the Langmuir decay instability (LDI) of electron plasma waves associated with stimulated Raman scattering. This observation is very important in the context of inertial confinement fusion because the LDI is a mechanism that may influence the stimulated Raman scattering saturation and growth. The experimental identification of those waves relies on Thomson scattering of a short wavelength probe beam. The Thomson scattered light was analyzed by two sets of spectrometer and streak camera providing information on the density fluctuations associated with the electron plasma waves and ion acoustic waves with temporal and spectral resolutions. Selection of a narrow range of angles (4 degrees of aperture) inside the probe and scattered light apertures provided necessary resolution in wave vector. The method used for the design of the Thomson scattering diagnostic is described as well as the technique used to clearly identify the observed ion acoustic waves as one of the Langmuir decay instability products. (C) 2000 American Institute of Physics. [S0034-6748(00)04809-7]. C1 Univ Paris 06, Ecole Polytech, CEA, CNRS,Lab Utilisat Lasers Intenses,UMR 7605, F-91128 Palaiseau, France. Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94550 USA. RP Depierreux, S (reprint author), Univ Paris 06, Ecole Polytech, CEA, CNRS,Lab Utilisat Lasers Intenses,UMR 7605, F-91128 Palaiseau, France. RI Fuchs, Julien/D-3450-2016 OI Fuchs, Julien/0000-0001-9765-0787 NR 44 TC 2 Z9 2 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 2000 VL 71 IS 9 BP 3391 EP 3401 AR PII [S0034-6748(00)04809-7] DI 10.1063/1.1288259 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 349GE UT WOS:000089036700023 ER PT J AU Loomba, D Halyo, V Lee, ER Lee, IT Kim, PC Perl, ML AF Loomba, D Halyo, V Lee, ER Lee, IT Kim, PC Perl, ML TI A new method for searching for free fractional charge particles in bulk matter SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ELECTRIC CHARGE AB We present a new experimental method for searching for free fractional charge in bulk matter; this new method derives from the traditional Millikan liquid drop method but allows the use of much larger drops, 20-100 mu m in diameter, compared to the traditional method that uses drops less than 15 mu m in diameter. These larger drops provide the substantial advantage that it is then much easier to consistently generate drops containing liquid suspensions of powdered meteorites and other special minerals. These materials are of great importance in bulk searches for fractional charge particles that may have been produced in the early universe. (C) 2000 American Institute of Physics. [S0034-6748(00)05709-9]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Loomba, D (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 13 TC 5 Z9 5 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 2000 VL 71 IS 9 BP 3409 EP 3414 AR PII [S0034-6748(00)05709-9] DI 10.1063/1.1308268 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 349GE UT WOS:000089036700025 ER PT J AU Ray, MD Sedlacek, AJ Wu, M AF Ray, MD Sedlacek, AJ Wu, M TI Ultraviolet mini-Raman lidar for stand-off, in situ identification of chemical surface contaminants SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB The Mini-Raman Lidar System (MRLS) is a portable chemical sensor that combines the spectral fingerprinting of Raman spectroscopy with the principles of solar-blind ultraviolet lidar for short-range, noncontact detection and identification of unknown substances on surfaces. The MRLS has the potential to detect contaminant films several microns thick at distances of meters and bulk quantities of substances at distances of tens of meters. The signal acquisition time is less than 1 min. The device has application to those involved in emergency response, environmental remediation, and military reconnaissance who respond initially at the site of a chemical spill or attack. (C) 2000 American Institute of Physics. [S0034- 6748(00)04409-9]. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Ray, MD (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 8 TC 42 Z9 44 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 2000 VL 71 IS 9 BP 3485 EP 3489 DI 10.1063/1.1288255 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 349GE UT WOS:000089036700038 ER PT J AU Oganessian, YT Utyonkov, VK Lobanov, YV Abdullin, FS Polyakov, AN Shirokovsky, IV Tsyganov, YS Gulbekian, G Bogomolov, SL Gikal, BN Mezentsev, AN Iliev, S Subbotin, VG Sukhov, AM Buklanov, GV Subotic, K Itkis, MG Moody, KJ Wild, JF Stoyer, NJ Stoyer, MA Lougheed, RW AF Oganessian, YT Utyonkov, VK Lobanov, YV Abdullin, FS Polyakov, AN Shirokovsky, IV Tsyganov, YS Gulbekian, G Bogomolov, SL Gikal, BN Mezentsev, AN Iliev, S Subbotin, VG Sukhov, AM Buklanov, GV Subotic, K Itkis, MG Moody, KJ Wild, JF Stoyer, NJ Stoyer, MA Lougheed, RW TI The synthesis of superheavy nuclei in the Ca-48+Pu-244 reaction SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT 23rd Symposium on Nuclear Physics CY JAN 10-13, 2000 CL INST MEXICANO SEGURO SOCIAL, OAXTEPEC, MEXICO SP Univ Nacl Autonoma Mexico, Inst Fis, Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Ctr Invest & Estudios Avanzados Inst Politecn Nacl, Soc Mexicana Fis, Consejo Nacl Ciencia & Technol, Ctr Latinoamer Fis HO INST MEXICANO SEGURO SOCIAL DE superheavy nuclei; alpha-decay; spontaneous fission; lifetimes ID ELEMENTS; FUSION; CA-48 AB The first results of experiments on the synthesis of superheavy nuclei, for which the modern nuclear theory predicts significant increase in stability, are presented. In a 34-day bombardment of a Pu-244 target with 5.2 x 10(18) Ca-48 ions using the Dubna Gas-filled Recoil Separator we observed a decay sequence consisting of an implanted heavy atom, three subsequent alpha-decays and spontaneous fission of heavy nuclei. The measured alpha-energies and corresponding time intervals were: E-alpha = 9.71 MeV (Delta t = 30.4 s), 8.67 MeV (Delta t = 15.4 min) and 8.83 MeV (Delta t = 1.6 min), for the spontaneous fission (Delta t = 16.5 min), the total deposited energy was approximately 190 MeV. The large alpha-particle energies together with the long decay times and spontaneous fission terminating the chain offer evidence of the decay of nuclei with high atomic numbers. The best candidate for the observed decay sequence is alpha-decay of the parent nucleus (289)114 produced in the Pu-244(Ca-48,3n) reaction with a section of about 1 pb. The lifetimes and alpha-particle energies of all observed new nuclei are in agreement with theoretical predictions for odd-even isotopes (289)114, (285)112 and (281)110. The significant increase in the lifetimes of the new Z = 112 and 110 daughters of the Z = 114 nuclide (by a factor of similar to 10(6)) with respect to the known heaviest isotopes of elements 112 and 110 can be considered direct proof of the existence of the "island of stability" of superheavy elements. C1 Joint Inst Nucl Res, Dubna 141980, Russia. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Joint Inst Nucl Res, Dubna 141980, Russia. EM utyonkov@sungns.jinr.ru; moody@isd.llnl.gov NR 31 TC 3 Z9 3 U1 0 U2 1 PU SOC MEXICANA FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD SEP PY 2000 VL 46 SU 1 BP 35 EP 41 PG 7 WC Physics, Multidisciplinary SC Physics GA 357UZ UT WOS:000089520300006 ER PT J AU Gross, CJ Ginter, TN Ressler, JJ Batchelder, JC Grzywacz, R Piechaczek, A Walters, WB Wiescher, M Rykaczewski, K Aprahamian, A Bingham, CR Janas, Z MacDonald, BD Zganjar, EF AF Gross, CJ Ginter, TN Ressler, JJ Batchelder, JC Grzywacz, R Piechaczek, A Walters, WB Wiescher, M Rykaczewski, K Aprahamian, A Bingham, CR Janas, Z MacDonald, BD Zganjar, EF TI Decay spectroscopy using the HRIBF recoil mass spectrometer SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT XXIIIrd Symposium on Nuclear Physics CY JAN 10-13, 2000 CL INST MEXICANO SEGURO SOCIAL, OAXTEPEC, MEXICO SP Univ Nacl Autonoma Mexico, Inst Fis, Univ Nacl Autonoma Mexico, Inst Ciencias Nucleares, Ctr Invest & Estudios Avanzados Inst Politecnico Nacl, Soc Mexicana Fis, Consejo Nacl Cienciy & Technol, Ctr Latinoamer Fis HO INST MEXICANO SEGURO SOCIAL DE recoil mass spectrometer; moving tape collector; proton and beta radioactivity ID PROTON EMITTERS; IDENTIFICATION; RADIOACTIVITY; NUCLEI; SYSTEM AB Two decay spectroscopy experiments performed with the Recoil Mass Spectrometer at the Holifield Radioactive Ion Beam Facility are described. Utilizing the Moving Tape Collector, the beta(+) decay half-life of Zr-80 has been measured to be 4.1(-0.6)(+0.8) s. The resulting decrease in mass 80 production during the rapid proton capture process, suggests that Zr-80 may not be a significant waiting point and the process may proceed to heavier masses. The observation of proton fine structure is reported for the first time in spherical nuclei. Three new decay branches, apparently from the two previously known states in Tm-146, have been observed using double-sided silicon strip detectors. Arising from the complex configuration mixing common to odd-odd nuclei, our preliminary results suggest relative energy differences and spins and parities in the Tm-146 parent and Er-145 daughter isotopes. C1 Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. RP Gross, CJ (reprint author), Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. RI Ressler, Jennifer Jo/F-2279-2010 NR 21 TC 0 Z9 0 U1 0 U2 1 PU SOCIEDAD MEXICANA DE FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD SEP PY 2000 VL 46 SU 1 BP 107 EP 112 PG 6 WC Physics, Multidisciplinary SC Physics GA 357UZ UT WOS:000089520300018 ER PT J AU Schmitz, M Tinoco, I AF Schmitz, M Tinoco, I TI Solution structure and metal-ion binding of the P4 element from bacterial RNase P RNA SO RNA-A PUBLICATION OF THE RNA SOCIETY LA English DT Article DE ion binding; NMR; RNase P ID IN-VITRO SELECTION; RIBONUCLEASE-P; NMR-SPECTROSCOPY; WATER SUPPRESSION; ESCHERICHIA-COLI; RIBOZYME; SPECTRA; SITE; THERMODYNAMICS; ARCHITECTURE AB We determined the solution structure of two 27-nt RNA hairpins and their complexes with cobalt(III)-hexammine (Co(NH3)(6)(3+)) by NMR spectroscopy. The RNA hairpins used in this study are the P4 region from Escherichia coli RNase P RNA and a C-to-U mutant that confers altered divalent metal-ion specificity (Ca2+ replaces Mg2+) for catalytic activity of this ribozyme, Co(NH3)(6)(3+) is a useful spectroscopic probe for Mg(H2O)(6)(2+)-binding sites because both complexes have octahedral symmetry and have similar radii. The thermodynamics of binding to both RNA hairpins was studied using chemical shift changes upon titration with Mg2+, Ca2+, and Co(NH3)(6)(3+). We found that the equilibrium binding constants for each of the metal ions was essentially unchanged when the P4 model RNA hairpin was mutated, although the NMR structures show that the RNA hairpins adopt different conformations. In the C-to-U mutant a C.G base pair is replaced by U.G, and the conserved bulged uridine in the P4 wild-type stem shifts in the 3' direction by 1 nt, Intermolecular NOE cross-peaks between Co(NH3)(6)(3+) and RNA protons were used to locate the site of Co(NH3)(6)(3+) binding to both RNA hairpins. The metal ion binds in the major groove near a bulge loop, but is shifted 5' by more than 1 bp in the mutant. The change of the metal-ion binding site provides a possible explanation for changes in catalytic activity of the mutant RNase P in the presence of Ca2+. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Tinoco, I (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM-10840] NR 40 TC 52 Z9 53 U1 0 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 1355-8382 J9 RNA JI RNA-Publ. RNA Soc. PD SEP PY 2000 VL 6 IS 9 BP 1212 EP 1225 DI 10.1017/S1355838200000881 PG 14 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 353VA UT WOS:000089295100002 PM 10999599 ER PT J AU Celina, M Graham, AC Gillen, KT Assink, RA Minier, LM AF Celina, M Graham, AC Gillen, KT Assink, RA Minier, LM TI Thermal degradation studies of a polyurethane propellant binder SO RUBBER CHEMISTRY AND TECHNOLOGY LA English DT Article; Proceedings Paper CT Fall Meeting of the American-Chemical-Society Rubber Division CY SEP 21-23, 1999 CL ORLANDO, FLORIDA SP Amer Chem Soc, Rubber Div ID HYDROXYL-TERMINATED POLYBUTADIENE; DIFFUSION-LIMITED OXIDATION; AGED ELASTOMERS; POLYMERS; HTPB; DECOMPOSITION; EXTRAPOLATION; ARRHENIUS; PROFILES; MODEL AB The thermal oxidative aging of a crosslinked hydroxy-terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) based polyurethane rubber used as a polymeric binder in solid propellant grain, was investigated at temperatures from 25 to 125 degreesC. The changes in tensile elongation, polymer network properties and chain dynamics, mechanical hardening and density were determined with a range of techniques including modulus profiling, solvent swelling, NMR relaxation and O-2 permeability measurements. We critically evaluated the Arrhenius methodology that is commonly used with a linear extrapolation of high temperature aging data using extensive data superposition and highly sensitive oxygen consumption experiments. The effects of other constituents in the propellant formulation on aging were also investigated. We conclude that crosslinking is the dominant process at higher temperatures and that the degradation involves only limited hardening in the bulk of the material. Significant curvature in the Arrhenius diagram of the oxidation rates was observed, This is similar to results for other rubber materials. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Celina, M (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 36 TC 43 Z9 44 U1 2 U2 16 PU AMER CHEMICAL SOC INC PI AKRON PA RUBBER DIV UNIV AKRON PO BOX 499, AKRON, OH 44309-0499 USA SN 0035-9475 J9 RUBBER CHEM TECHNOL JI Rubber Chem. Technol. PD SEP-OCT PY 2000 VL 73 IS 4 BP 678 EP 693 DI 10.5254/1.3547613 PG 16 WC Polymer Science SC Polymer Science GA 374WZ UT WOS:000165368500008 ER PT J AU Hassler, SW Robey, HF Simonson, BM AF Hassler, SW Robey, HF Simonson, BM TI Bedforms produced by impact-generated tsunami, similar to 2.6 Ga Hamersley basin, Western Australia SO SEDIMENTARY GEOLOGY LA English DT Article DE wave ripples; impact; tsunami; Hamersley basin; Late Archean; modeling ID WITTENOOM FORMATION; IRON-FORMATION; EJECTA; SPHERULES; HORIZON; DEPOSITS; IRIDIUM; EVENTS AB Late Archean strata in the Hamersley basin of Western Australia contain a layer of anorbital wave ripples composed largely of impact-generated melt spherules. Sedimentologic evidence indicates that these ripples formed in a deep marine shelf setting well below the effects of meteorological processes. Combined with the impact-related origin of the spherules, this suggests that the ripples were formed by an impact-generated tsunami. To test if this geologic interpretation is reasonable, we have modeled anorbital ripple formation by impact-generated tsunami waves in the Hamersley basin. We assume a deep ocean target area, and that tsunami waves traveled from the target area unhindered to the Hamersley basin. Using melt spherule radius as an indicator, we infer a bolide diameter of 4.9 km. Assuming a bolide density of 2.6 and a velocity of 20 km/s, this impact would produce a crater 60.4 km in diameter. We modeled tsunami waves generated by the collapse of this crater, and propagated them into the Hamersley basin using shallow water wave theory. The wave models indicate tsunami waves created at impacts between 2000 and 8000 km from the Hamersley basin could have generated the observed anorbital ripples. (C) 2000 Published by Elsevier Science B.V. C1 Calif State Univ Hayward, Dept Geol Sci, Hayward, CA 94542 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Oberlin Coll, Dept Geol, Oberlin, OH 44074 USA. RP Hassler, SW (reprint author), Calif State Univ Hayward, Dept Geol Sci, Hayward, CA 94542 USA. NR 42 TC 26 Z9 28 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0037-0738 J9 SEDIMENT GEOL JI Sediment. Geol. PD SEP PY 2000 VL 135 IS 1-4 BP 283 EP 294 DI 10.1016/S0037-0738(00)00078-6 PG 12 WC Geology SC Geology GA 357FU UT WOS:000089488500021 ER PT J AU Dubbin, WE Sposito, G Zavarin, M AF Dubbin, WE Sposito, G Zavarin, M TI X-ray absorption spectroscopic study of Cu-glyphosate adsorbed by microcrystalline gibbsite SO SOIL SCIENCE LA English DT Article DE glyphosate; gibbsite; adsorption; EXAFS; Cu; X-ray absorption; spectroscopy ID MULTIPLE-SCATTERING CALCULATIONS; COPPER(II) COMPLEXES; HUMIC SUBSTANCES; N-PHOSPHONOMETHYLGLYCINE; WATER INTERFACE; ADSORPTION; CU(II); SOILS; LIGANDS; MONTMORILLONITE AB Glyphosate [N-(phosphonomethyl)glycine] is a broad-spectrum herbicide that is used widely in agriculture, forestry, and urban settings, It is one of the most heavily applied pesticides in the US, with an annual use greater than 12 million kg, When added to soil glyphosate is readily sorbed, losing both its efficacy as an herbicide and its potential for translocation, Despite such tenacious binding to soil colloids, the adsorbent surface offers little protection from biodegradation because the glyphosate decomposes so rapidly, with a half-life as short as several days, Attempts to elucidate the sorption mechanism of glyphosate, thereby providing a mechanistic explanation for this biolability, have thus far been unsuccessful, Therefore, the goal of this research was to derive the architecture of an important mo del system, the Cu-glyphosate-gibbsite surface complex, in which Cu serves as a probe of the local bonding environment and gibbsite serves as a representative soil mineral adsorbent, Copper K-edge extended X-ray absorption fine structure (EXAFS) spectra of Cu-glyphosate complexes in aqueous solution at pH 5.5 revealed Cu complexation by the phosphonate moiety, Introduction of microcrystalline gibbsite resulted in the loss of P from the coordination sphere of Cu and the formation of a ternary complex through chemisorption of the phosphonate group to the oxide surface. The EXAFS spectra of Cu in the Cu-glyphosate-gibbsite surface complex matched spectra for Cu-glycine and Cu-methylglycine complexes in aqueous solution, thereby providing evidence for Cu complexation by the carboxyl O and amine N, Despite the chemisorption of glyphosate to oxide surfaces via the phosphonate group, the distal end of the glyphosate molecule extends into aqueous solution where it may be biodegraded rapidly. C1 Nat Hist Museum, Dept Mineral, London SW7 5BD, England. Univ Calif Berkeley, Div Ecosyst Sci, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Dubbin, WE (reprint author), Nat Hist Museum, Dept Mineral, London SW7 5BD, England. NR 45 TC 21 Z9 22 U1 2 U2 20 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0038-075X J9 SOIL SCI JI Soil Sci. PD SEP PY 2000 VL 165 IS 9 BP 699 EP 707 DI 10.1097/00010694-200009000-00003 PG 9 WC Soil Science SC Agriculture GA 358ZB UT WOS:000089586100003 ER PT J AU Jackson, BP Miller, WP AF Jackson, BP Miller, WP TI Effectiveness of phosphate and hydroxide for desorption of arsenic and selenium species from iron oxides SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID PLASMA-MASS SPECTROMETRY; EXTRACTION TECHNIQUES; ADSORPTION; SOILS; SPECIATION; CHROMATOGRAPHY; FERRIHYDRITE; ABSORPTION; SEDIMENTS; GOETHITE AB Phosphate and OH- are often used for the extraction of As and Se from soils, either as single extractants or as part of a sequential extraction scheme. However, the recovery of As and Se species and the integrity of the resulting solution speciation merit investigation. In this study the relative effectiveness of PO4 at 0.1 and 0.5 XI and pH values of 3 and 6.7 and 0.1 Ai OH- to extract As(III), As(V), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), p-arsanilic acid (p-ASA), roxarsone (ROX), Se(IV) and Se(VI) sorbed to goethite and an amorphous Fe oxide mere compared, and the speciation in the resulting extract was determined. The extent to which 0.1 M PO4 added to 0.25 iii NH2OH . HCl or 0.175 M Na oxalate/0.1,II oxalic acid prevents readsorption of As(V) or Se(IV) to goethite during the dissolution of an amorphous Fe oxide was also assessed. Hydroxide was the most effective extractant for desorption of all species except As(III) from both oxide surfaces. Arsenite was extracted most efficiently by 0.5 M PO4 at low pH; however, amorphous Fe oxide exhibited a strong affinity for As(III) with a maximum of 18% of As(III) extracted by 0.5 M PO4 at pH 2.8. Partial oxidation of As(III) to As(V) occurred in all extractions where an Fe oxide solid phase was present, but only in the hydroxide extract in the absence of a Fe solid phase. Addition of 0.1 M PO4 to extractants used for the dissolution of the amorphous Fe oxide prevented the readsorption of As(V) and Se(IV) to goethite. C1 Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environ Sci, Aiken, SC 29803 USA. Univ Georgia, Dept Crop & Soil Sci, Athens, GA 30602 USA. RP Jackson, BP (reprint author), Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environ Sci, Aiken, SC 29803 USA. NR 41 TC 129 Z9 148 U1 6 U2 58 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD SEP-OCT PY 2000 VL 64 IS 5 BP 1616 EP 1622 PG 7 WC Soil Science SC Agriculture GA 360VT UT WOS:000089688600010 ER PT J AU Monier, C Chang, PC Li, NY LaRoche, JR Baca, AG Hou, HQ Ren, F Pearton, SJ AF Monier, C Chang, PC Li, NY LaRoche, JR Baca, AG Hou, HQ Ren, F Pearton, SJ TI Simulation and design of InGaAsN-based heterojunction bipolar transistors for complementary low-power applications SO SOLID-STATE ELECTRONICS LA English DT Article DE AlGaAs/InGaAsN; heterojunction bipolar transistor; two-dimensional simulation; pnp configuration; DC current gain; dopant-graded doping; turn-on voltage; high-frequency characteristics ID LASER-DIODES; CURRENT-GAIN; BAND-GAP; P-N; EPITAXY; HBT AB The performance capabilities of pnp InGaAsN-based heterojunotion bipolar transistors (HBTs) for use in complementary NET technology have been theoretically addressed with a two-dimensional simulation program based on the drift-diffusion model. Simulation results closely reproduce the DC characteristics experimentally observed from the first demonstrated pnp AlGaAs/InGaAsN HBT with a current gain of Is and a turn-on voltage around 0.89 V. Numerous design approaches have been explored to maximize the transistor performances. As a result, a substantial improvement of the DC current gain (by a factor of 2-3) and high-frequency operation performances (with f(T) and f(MAX) values up to 10 GHz) can be easily achieved with the proper use of varying base thickness X-B and dopant-graded base. The effect of the quaternary band-gap value E-G is also addressed. Simulation results show that pup device with turn-on voltage similar to 0.7 V can be produced by lowering E-G to 1.0 cV, without any important degradation of DC and RF properties, because hole transport at the emitter/base side is not strongly affected. The replacement of the InGaAsN collector by GaAs is finally reported. Comparable DC and improved RF simulated performances are observed fr om this double HBT structure that takes advantages of the negligible valence band offset at the base/collector interface. These encouraging performances demonstrate the practicability of using InGaAsN-based HBTs for complementary low-power applications. (C) 2000 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. EMCORE Corp, Emcore Photovolta, Albuquerque, NM 87123 USA. Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. RP Monier, C (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD SEP PY 2000 VL 44 IS 9 BP 1515 EP 1521 DI 10.1016/S0038-1101(00)00131-3 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 355HR UT WOS:000089380700001 ER PT J AU Borca-Tasciuc, T Liu, WL Liu, JL Zeng, TF Song, DW Moore, CD Chen, G Wang, KL Goorsky, MS Radetic, T Gronsky, R Koga, T Dresselhaus, MS AF Borca-Tasciuc, T Liu, WL Liu, JL Zeng, TF Song, DW Moore, CD Chen, G Wang, KL Goorsky, MS Radetic, T Gronsky, R Koga, T Dresselhaus, MS TI Thermal conductivity of symmetrically strained Si/Ge superlattices SO SUPERLATTICES AND MICROSTRUCTURES LA English DT Article DE thermal conductivity; superlattice; thermoelectrics phonon engineering ID FIGURE; MERIT AB This paper reports temperature-dependent thermal conductivity measurements in the cross-lane direction of symmetrically strained Si/Ge superlattices, and the effect of doping, period thickness and dislocations on the thermal conductivity reduction of Si/Ge superlattices. The Si/Ge superlattices are grown by molecular beam epitaxy on silicon and silicon-insulator substrates with a graded buffer layer. A differential 3 omega method is used to mea sure the thermal conductivity of the buffer and the superlattices between 80 and 300 K. The thermal conductivity measurement is carried out in conjunction with X-ray and TEM sample characterization. The measured thermal conductivity values of the superlattices are lower than those of their equivalent composition bulk alloys. (C) 2000 Academic Press. C1 Univ Calif Los Angeles, Dept Aerosp & Mech Engn, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA. RP Chen, G (reprint author), Univ Calif Los Angeles, Dept Aerosp & Mech Engn, Los Angeles, CA 90095 USA. RI Chen, Gang/J-1325-2014; Koga, Takaaki/H-1973-2011 OI Chen, Gang/0000-0002-3968-8530; NR 25 TC 150 Z9 153 U1 6 U2 67 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0749-6036 J9 SUPERLATTICE MICROST JI Superlattices Microstruct. PD SEP PY 2000 VL 28 IS 3 BP 199 EP 206 DI 10.1006/spmi.2000.0900 PG 8 WC Physics, Condensed Matter SC Physics GA 361KZ UT WOS:000089723400005 ER PT J AU Kung, KY Chen, P Wei, F Shen, YR Somorjai, GA AF Kung, KY Chen, P Wei, F Shen, YR Somorjai, GA TI Sum-frequency generation spectroscopic study of CO adsorption and dissociation on Pt(111) at high pressure and temperature SO SURFACE SCIENCE LA English DT Letter DE carbon monoxide; chemisorption; platinum; surface roughening ID VIBRATIONAL PHASE RELAXATION; CARBON-MONOXIDE; PLATINUM SURFACE; SPECTRA; CHEMISORPTION AB Surface vibrational spectroscopy using infrared-visible sum-frequency generation was applied to the study of CO adsorption on the Pt(111) surface under high CO pressure at various temperatures. The temperature variation of the spectrum is reversible below 623 K. At similar to 673 K, the spectrum changes with time, showing that most CO is thermally desorbed from the surface, some dissociated leaving carbon on the surface, and the platinum surface is presumably modified. A roughened platinum surface is effectively annealed under high CO pressure at room temperature. CO co-adsorbed with carbon on the surface causes a downshift in the frequency of the CO stretch peak. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Natl Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Chen, Peilin/E-2728-2010 OI Chen, Peilin/0000-0003-4154-0487 NR 22 TC 34 Z9 34 U1 3 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 1 PY 2000 VL 463 IS 2 BP L627 EP L633 DI 10.1016/S0039-6028(00)00639-7 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 355HN UT WOS:000089380400001 ER PT J AU Ramshaw, JD AF Ramshaw, JD TI Brownian motion in multiphase flow SO THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS LA English DT Article ID 2-PHASE FLOW; MULTICOMPONENT DIFFUSION; APPROXIMATION; EQUATIONS; STABILITY AB A previous phenomenological theory for Brownian motion of rigid spherical particles in a flowing fluid Ramshaw, 1979, 1981) is extended to multiphase mixtures and arbitrary how regimes. It is argued that each phase i possesses its own intrinsic osmotic pressure q(i) = n(i)k(B)T, where n(i) is the mean number of discrete particles (i.e., inclusions, fragments, blobs, or chunks) of phase i per unit total volume, regardless of their rigidity or their size and shape distributions. The gradient of q(i) appears as an additional force term in the momentum equation for phase i. The osmotic pressures q(i) also contribute to the total pressure p of the mixture, so these contributions must be subtracted out before the conventional multiphase pressure forces are computed. The resulting pressure terms in the momentum equation for phase i then become -alpha(i)del(p - q) - del q(i) , where alpha(i) is the volume fraction of phase i and q = Sigma(i) q(i). This formulation provides a single unified description of the flow of both multiphase mixtures and multicomponent gases, and exhibits a smooth transition between these two limiting cases as the particle sizes vary from macroscopic to molecular dimensions. The stability properties of the equations are examined in the incompressible limit, and it is found that the Brownian motion stabilizes and regularizes the system only for microscopically small relative velocities. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Ramshaw, JD (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-097, Livermore, CA 94551 USA. NR 25 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0935-4964 J9 THEOR COMP FLUID DYN JI Theor. Comput. Fluid Dyn. PD SEP PY 2000 VL 14 IS 3 BP 195 EP 202 DI 10.1007/s001620050136 PG 8 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 361EG UT WOS:000089709400003 ER PT J AU Iyengar, SS Kouri, DJ Hoffman, DK AF Iyengar, SS Kouri, DJ Hoffman, DK TI Particular and homogeneous solutions of time-independent wavepacket Schrodinger equations: calculations using a subset of eigenstates of undamped or damped Hamiltonians SO THEORETICAL CHEMISTRY ACCOUNTS LA English DT Article DE time-independent wavepackets; distributed approximating functionals; spectral density operator; eigen function calculations of scattering amplitudes ID LIPPMANN-SCHWINGER EQUATIONS; DISTRIBUTED APPROXIMATING FUNCTIONALS; ABSORBING BOUNDARY-CONDITIONS; WAVE PACKET APPROACH; FILTER-DIAGONALIZATION; POLYNOMIAL EXPANSION; SCATTERING CALCULATIONS; QUANTUM DYNAMICS; PROPAGATION; REPRESENTATION AB A variety of causal, particular and homogeneous solutions to the time-independent wavepacket Schrodinger equation have been considered as the basis for calculations using Chebychev expansions, finite-tau expansions obtained from a partial Fourier transform of the time-dependent Schrodinger equation, and the distributed approximating functional (DAF) representation for the spectral density operator (SDO). All the approximations are made computationally robust and reliable by damping the discrete Hamiltonian matrix along the edges of the finite grid to facilitate the use of compact grids. The approximations are found to be completely well behaved at all values of the (continuous) scattering energy. It is found that the DAF-SDO provides a suitable alternative to Chebychev propagation. C1 Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Kouri, DJ (reprint author), Univ Houston, Dept Chem, Univ Pk, Houston, TX 77204 USA. RI Iyengar, Srinivasan/B-5570-2017 OI Iyengar, Srinivasan/0000-0001-6526-2907 NR 59 TC 14 Z9 14 U1 0 U2 2 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1432-881X J9 THEOR CHEM ACC JI Theor. Chem. Acc. PD SEP PY 2000 VL 104 IS 6 BP 471 EP 483 DI 10.1007/s002140000175 PG 13 WC Chemistry, Physical SC Chemistry GA 365CF UT WOS:000089930300007 ER PT J AU Colitz, CMH Malarkey, DE Woychik, RP Wilkinson, JE AF Colitz, CMH Malarkey, DE Woychik, RP Wilkinson, JE TI Persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous in transgenic line TgN3261Rpw SO VETERINARY PATHOLOGY LA English DT Article DE embryology; eye; mice; persistent hyperplastic primary vitreous; persistent hyperplastic tunica vasculosa lentis ID STAFFORDSHIRE BULL TERRIER; CGMP-PHOSPHODIESTERASE; RETINAL DEGENERATION; EARLY MORPHOGENESIS; BETA-SUBUNIT; MICE; MOUSE; TISSUE; YELLOW; EXPRESSION AB Persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous are congenital ocular anomalies that can lead to cataract formation. A line of insertional mutant mice, TgN3261Rpw, generated at the Oak Ridge National Laboratory in a large-scale insertional mutagenesis program was found to have a low incidence (8/243; 3.29%) of multiple developmental ocular abnormalities. The ocular abnormalities include persistent hyperplastic primary vitreous, persistent hyperplastic tunica vasculosa lentis, failure of cleavage of the anterior segment, retrolental fibrovascular membrane, posterior polar cataract, and detached retina. This transgenic mouse line provides an ontogenetic model because of the high degree of similarity of this entity in humans, dogs, and mice. C1 N Carolina State Univ, Coll Vet Med, Dept Compan Anim & Special Species Med, Raleigh, NC USA. N Carolina State Univ, Coll Vet Med, Dept Microbiol Pathol & Parasitol, Raleigh, NC USA. Oak Ridge Natl Lab, Div Biol, Oak Ridge, TN 37831 USA. Univ Tennessee, Coll Vet Med, Dept Pathol, Knoxville, TN USA. RP Colitz, CMH (reprint author), Louisiana State Univ, Sch Vet Med, Dept Vet Clin Sci, S Stadium Dr, Baton Rouge, LA 70803 USA. NR 37 TC 9 Z9 10 U1 0 U2 1 PU AMER COLL VET PATHOLOGIST PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0300-9858 J9 VET PATHOL JI Vet. Pathol. PD SEP PY 2000 VL 37 IS 5 BP 422 EP 427 DI 10.1354/vp.37-5-422 PG 6 WC Pathology; Veterinary Sciences SC Pathology; Veterinary Sciences GA 364BE UT WOS:000089871500006 PM 11055865 ER PT J AU Upton, C Hogg, D Perrin, D Boone, M Harris, NL AF Upton, C Hogg, D Perrin, D Boone, M Harris, NL TI Viral genome organizer: a system for analyzing complete viral genomes SO VIRUS RESEARCH LA English DT Article DE viral genomes; genes; PCR primers ID SEQUENCE AB The viral genome organizer (VGO) is designed to simplify the characterization and annotation of complete viral genomes (particularly those of large poxviruses) and to help researchers discover new genes and detect gene fragmentation. VGO is based on Genotator [Harris, N.L., 1997. Genome Res. 7, 754-762], an annotation workbench designed for the analysis of eukaryotic genomic sequences. VGO automates a number of database search routines (FASTA, BLASTP, PSI-BLAST and TBLASTN), processes the results through a multiple-alignment viewer (MView; [Brown, N.P., Leroy, C., Sander, C., 1998. Bioinformatics 14, 380-381]) and serves to manage the hundreds of DNA, protein and database search results files that must be organized when dealing with large complete poxviral genomes. It also directs the generation a self-dotplot of the genome by Dotter [Sonnhammer, E.L.L., Durbin, R., 1995. A dot-matrix program with dynamic threshold control suited for genomic DNA and protein sequence analysis. Gene 167: GC1-10. http://www.sanger.ac.uk/Software/Dotter/] to uncover repeated genes and sequences and provides Internet links to programs for generation of restriction maps and analysis of potential PCR primers. The user-friendly graphical interface displays DNA and protein sequences, links to search results, ORFs, stop-start codons, restriction sites and flags of database searches. Currently, VGO and associated programs run in an X-windows environment on commonly available UNIX machines. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Victoria, Dept Biochem & Microbiol, Victoria, BC V8W 3P6, Canada. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley Drosophila Genome Project, Berkeley, CA 94720 USA. RP Upton, C (reprint author), Univ Victoria, Dept Biochem & Microbiol, POB 3055,150 Petch Bldg, Victoria, BC V8W 3P6, Canada. RI Upton, Chris/A-4670-2008 NR 10 TC 33 Z9 34 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1702 J9 VIRUS RES JI Virus Res. PD SEP PY 2000 VL 70 IS 1-2 BP 55 EP 64 DI 10.1016/S0168-1702(00)00210-0 PG 10 WC Virology SC Virology GA 373BL UT WOS:000165268500006 PM 11074125 ER PT J AU Tartakovsky, DM Moulton, JD Zlotnik, VA AF Tartakovsky, DM Moulton, JD Zlotnik, VA TI Kinematic structure of minipermeameter flow SO WATER RESOURCES RESEARCH LA English DT Article ID PERMEABILITY; AQUIFERS AB Minipermeameters are rapidly becoming a popular tool for collecting localized measurements of permeability in both laboratory and field studies. While one of the main advantages of minipermeameters is their ability to collect data on various support volumes, there have been only limited attempts to analyze their size and geometry. We define the support volume of minipermeameter measurements as a region containing 90% of the total gas flow, i.e., a region bounded by the 10% streamline. Using our new semianalytical solutions for the Stokes' stream function, we demonstrate that the support volume has a shape of the semitoroid adjacent to the sample surface. Hence there is a blind spot directly below the minipermeameter, which is not probed by the measurement. We demonstrate that the support volume of the minipermeameter measurements decreases with the tip-seal's ratio (a ratio of the inner tip-seal radius to the outer tip-seal radius), while the size of the corresponding blind spot increases. C1 Univ Calif Los Alamos Natl Lab, Comp Res & Applicat Grp, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Math Modeling & Anal Grp, Los Alamos, NM 87545 USA. Univ Nebraska, Dept Geosci, Lincoln, NE 68588 USA. RP Tartakovsky, DM (reprint author), Univ Calif Los Alamos Natl Lab, Comp Res & Applicat Grp, POB 1663, Los Alamos, NM 87545 USA. RI Tartakovsky, Daniel/E-7694-2013 NR 28 TC 21 Z9 21 U1 0 U2 3 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 SEP PY 2000 VL 36 IS 9 BP 2433 EP 2442 DI 10.1029/2000WR900178 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 351XE UT WOS:000089184100003 ER PT J AU RamaRao, BS LaVenue, AM de Marsily, G Marietta, MG AF RamaRao, BS LaVenue, AM de Marsily, G Marietta, MG TI Comment on RamaRao et al. [1995] and LaVenue et al. [1995] - Reply SO WATER RESOURCES RESEARCH LA English DT Editorial Material ID GROUNDWATER-FLOW MODEL; SIMULATED TRANSMISSIVITY FIELDS; PILOT POINT METHODOLOGY; GEOSTATISTICAL APPROACH; AUTOMATED CALIBRATION; INFORMATION; PARAMETERS; ENSEMBLE C1 Duke Engn & Serv, Austin, TX 78758 USA. Waterstone Environm Hydrol & Engn, Boulder, CO 80301 USA. Univ Paris 06, UMR Sisyphe, Lab Geol Appl, F-75252 Paris, France. Sandia Natl Labs, Carlsbad, NM 88220 USA. RP RamaRao, BS (reprint author), Duke Engn & Serv, 9111 Res Blvd, Austin, TX 78758 USA. NR 18 TC 3 Z9 3 U1 0 U2 1 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 SEP PY 2000 VL 36 IS 9 BP 2799 EP 2803 DI 10.1029/2000WR900175 PG 5 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 351XE UT WOS:000089184100036 ER PT J AU Johnson, DW Susfalk, RB Gholz, HL Hanson, PJ AF Johnson, DW Susfalk, RB Gholz, HL Hanson, PJ TI Simulated effects of temperature and precipitation change in several forest ecosystems SO JOURNAL OF HYDROLOGY LA English DT Article DE temperature; precipitation; forests; nutrients; soils; litter ID INCREASED SOIL-TEMPERATURE; RED SPRUCE; NITROGEN MINERALIZATION; LITTER DECOMPOSITION; BOREAL FORESTS; CLIMATE-CHANGE; UNITED-STATES; LOBLOLLY-PINE; MOUNTAINS; TENNESSEE AB The Nutrient Cycling Model (NuCM) was used to investigate the effects of increased temperature (+4 degrees C) and changing precipitation (increased and decreased) on biogeochemical cycling at six forest sites in the United States: a Picea rubens forest at Nolan Divide in the Great Smoky Mountains, North Carolina; mixed deciduous forests at Walker Branch, Tennessee and Coweeta, North Carolina; a Pinus tacda forest at Duke, North Carolina; a P. eliottii forest at Bradford, Florida; and a P. conrota/P, jeffreyii forest at Little Valley, Nevada. Simulations of increased temperature indicated increased evapotranspiration and reduced water Aux, Simulations of changes in precipitation indicated disproportionately large variations in soil water flux because of the relative stability of evapotranspiration with changes in precipitation. Increased temperature caused N release from forest floors at all sites. Ar the N-saturated Nolan Divide site, this resulted in no change in N uptake or growth but increased soil solution Al and NO; and increased N leaching losses. At the N-limited sites, the release of N from the forest floor caused increased growth, and, in some cases, increased NO; leaching as well, indicating that N released from the forest floor was not efficiently taken up by the vegetation. Increased precipitation caused increased growth, and decreased precipitation caused reduced growth in the N-limited sites because of changes in wet N deposition. Changes in precipitation had no effect on growth in the N-saturated Nolan Divide site, but did cause large changes in soil solution mineral acid anion and Al concentrations, Increased precipitation caused long-term decreases in soil exchangeable base cations in most cases because of the disproportionately large effects on soil water flux; however, increased precipitation caused decreases in exchangeable base cations in cases when atmospheric deposition was a major source of base cations for the system. The simulation results illustrate the extreme complexity of the possible responses of nutrient cycling processes to climate change. By virtue of the fact that the NuCM model does not contain physiological algorithms, these simulations demonstrate that changes in temperature and precipitation can produce widely varying ecosystem-level responses through their effects on biogeochemical cycling processes alone and that generalizations about the relative importance of temperature versus precipitation changes are hazardous. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Desert Res Inst, Reno, NV 89512 USA. Univ Nevada, Reno, NV 89512 USA. Univ Florida, Gainesville, FL 32611 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Johnson, DW (reprint author), Desert Res Inst, 2215 Raggio Pkwy, Reno, NV 89512 USA. RI Hanson, Paul J./D-8069-2011 OI Hanson, Paul J./0000-0001-7293-3561 NR 33 TC 12 Z9 15 U1 3 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD AUG 31 PY 2000 VL 235 IS 3-4 BP 183 EP 204 DI 10.1016/S0022-1694(00)00266-3 PG 22 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 352EC UT WOS:000089200700003 ER PT J AU Jeong, JY Park, J Henins, I Babayan, SE Tu, VJ Selwyn, GS Ding, G Hicks, RF AF Jeong, JY Park, J Henins, I Babayan, SE Tu, VJ Selwyn, GS Ding, G Hicks, RF TI Reaction chemistry in the afterglow of an oxygen-helium, atmospheric-pressure plasma SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID JET AB The reaction chemistry in the afterglow of a non-equilibrium, capacitive discharge, operated at 600 Torr total pressure with (0.5 to 5.0) x 10(17) cm(-3) of oxygen in helium, has been examined by ultraviolet absorption spectroscopy, optical emission spectroscopy, and numerical modeling. The densities of the active species, O(P-3), O-2((1)Delta(g)), O-2((1)Sigma(g)(+)), and O-3, have been determined as a function of the operating conditions. At RF power densities between 6.1 and 30.5 W/cm(3) and a neutral temperature of 100 +/- 40 degrees C, the plasma generated (0.2 to 1.0) x 10(16) cm(-3) of O(P-3) and O-2((1)Delta(g)), (0.2 to 2.0) x 10(15) cm(-3) of O-2((1)Sigma(g)(+)), and (0.1 to 4.0) x 10(15) cm(-3) of O-3. After the power was turned off, the singlet-sigma and singlet-delta states decayed within 0.1 and 30.0 Ins, respectively. The concentration of oxygen atoms remained constant for about 0.5 ms, then fell rapidly due to recombination with O-2 to form O-3. It was found that the etching rate of polyimide correlated with the concentration of oxygen atoms in the afterglow, indicating that the O atoms were the active species involved in this process. C1 Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hicks, RF (reprint author), Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. NR 30 TC 139 Z9 142 U1 3 U2 42 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 31 PY 2000 VL 104 IS 34 BP 8027 EP 8032 DI 10.1021/jp0012449 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 349VX UT WOS:000089067200013 ER PT J AU Rodriguez, JA Hanson, JC Chaturvedi, S Maiti, A Brito, JL AF Rodriguez, JA Hanson, JC Chaturvedi, S Maiti, A Brito, JL TI Studies on the behavior of mixed-metal oxides: Structural, electronic, and chemical properties of beta-FeMoO4 SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID TEMPERATURE-PROGRAMMED REDUCTION; TOTAL-ENERGY CALCULATIONS; BAND-GAP SIZE; OXIDATIVE DEHYDROGENATION; MOSSBAUER-SPECTROSCOPY; SELECTIVE OXIDATION; MOLECULAR-DYNAMICS; POWDER DIFFRACTION; MO OXIDES; CATALYSTS AB The structural and electronic properties of iron molybdate (FeMoO4) have been studied using synchrotron-based time-resolved X-ray diffraction (TR-XRD), X-ray absorption near-edge spectroscopy (XANES), and first-principles density functional (DFT-GGA) calculations. The beta phase of FeMoO4 is stable in a large range of temperatures (25-800 degrees C). For beta-FeMoO4, the results of Reitveld refinement and DFT-GGA calculations give a crystal structure in which Fe is in an almost octahedral environment while Mo is tetracoordinated. The Mo L-lI-edge XANES spectra of beta-FeMoO4 exhibit a line shape that is typical of oxides in which Mo is in a tetrahedral environment. The valence electronic structure of beta-FeMoO4 is characterized by an intense peak with Fe 3d character near the top of the valence band. The iron molybdate displays a good chemical affinity for H-2, H2S, and SO2. H-2-TPR (temperature programmed reduction) spectra for beta-FeMoO4 show consumption of hydrogen and evolution of water (beta-FeMoO4 + H-2,(gas) --> H2Ogas + FeMoOx) between 600 and 850 degrees C. Upon exposure to H2S at moderate temperatures (50-250 degrees C), there is formation of sulfides and sulfates on the oxide. H2S exposure at elevated temperatures (350-450 degrees C) leads to formation of FeMoSx compounds without SOx species (beta-FeMoO4 + H2,Sgas --> H2Ogas + FeMoSx). beta-FeMoO4 is a good sorbent for sulfur dioxide. The adsorption of SO2 on beta-FeMoO4 at room temperature produces SO3 and SO4 groups without dissociation of SO2. A correlation is found between changes in the electronic and chemical properties of beta-FeMoO4, beta-NiMoO4, and beta-MgMoO4. beta-NiMoO4 exhibits a large density of metal states near the top of its valence band and a substantial reactivity toward H-2 and H2S. beta-MgMoO4 displays completely opposite trends, and beta-FeMoO4 is an intermediate case between the two extremes. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Mol Simulat Inc, San Diego, CA 92121 USA. Inst Venezolano Invest Cient, Ctr Quim, Caracas 1020A, Venezuela. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Brito, Joaquin/F-4974-2010; Hanson, jonathan/E-3517-2010 NR 63 TC 38 Z9 38 U1 4 U2 80 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 31 PY 2000 VL 104 IS 34 BP 8145 EP 8152 DI 10.1021/jp001652c PG 8 WC Chemistry, Physical SC Chemistry GA 349WJ UT WOS:000089068300009 ER PT J AU Su, Y Balmer, ML Bunker, BC AF Su, Y Balmer, ML Bunker, BC TI Raman spectroscopic studies of silicotitanates SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MICROPOROUS TITANOSILICATE ETS-10; CRYSTAL-STRUCTURE; TITANIUM SILICALITE; VIBRATIONAL-SPECTRA; HYDROGEN-PEROXIDE; GLASSES; DIFFRACTION; BA2TISI2O8; SILICATES; ZEOLITES AB Silicotitanates are nanoporous materials that have been used as selective ion exchangers for removing cesium from waste streams and catalysts for promoting oxidation and hydroxylation reactions. The local bonding configurations and network charge distribution are known to influence the selectivity and reactivity of these compounds. We have synthesized a group of new silicotitanates using sol-gel and solid-state techniques. Raman spectroscopy has been used to systematically examine the vibrational behavior of these compounds. By correlating the variations of Raman spectra with titanium coordinations of these compounds, the relationship between Raman shifts and the local bonding configurations around silicon and titanium is proposed. C1 Pacific NW Natl Lab, Mat Resources & Environm Mol Sci Lab, Richland, WA 99352 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Su, Y (reprint author), Pacific NW Natl Lab, Mat Resources & Environm Mol Sci Lab, Richland, WA 99352 USA. NR 48 TC 108 Z9 109 U1 11 U2 36 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 31 PY 2000 VL 104 IS 34 BP 8160 EP 8169 DI 10.1021/jp0018807 PG 10 WC Chemistry, Physical SC Chemistry GA 349WJ UT WOS:000089068300011 ER PT J AU Phillips, J Kelly, D Radovic, L Xie, F AF Phillips, J Kelly, D Radovic, L Xie, F TI Microcalorimetric study of the influence of surface chemistry on the adsorption of water by high surface area carbons SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ACTIVATED CARBON; VAPOR ADSORPTION; MICROPOROUS STRUCTURES; MOLECULAR SIMULATION; SILICATE SURFACES; ADSORBENTS; ISOTHERM AB Microcalorimetric techniques have been employed to investigate the adsorption of water on chemically modified, high surface area carbons. A matrix of treatments and carbons were selected to test some hypotheses. Heats of adsorption of water indicate that adsorption is a strong function of surface chemistry. Three mechanisms of water adsorption are delineated according to measured differential heats of adsorption (H-ads): (i) chemical adsorption with H-ads > 12 kcal/mol, (ii) condensation with H-ads approximately 10 kcal/nzol, and (iii) physical adsorption with H-ads < 10 kcal/mol. The absolute and relative amounts of water adsorption arising from each mechanism are a function of surface chemistry. Adsorption of water on carbons dried at 175 degrees C in N-2 generates typical Type V adsorption isotherms. Heat of adsorption data for water adsorbed on dried car bon indicates that condensation accounts for the sharp rise in adsorption at a relative humidity of approximately 0.5. Treating carbons with N-2 at 950 degrees C generates surfaces that initially adsorb water through a mechanism of chemical adsorption, followed by condensation, and finally physical adsorption. On high-temperature N-2-treated carbons heats of adsorption exceed 100 kcal/mol, suggesting chemisorption of water at unsaturated carbon surface sites produced during the high-temperature reduction of oxygen species. Carbons reduced with H-2 at 950 degrees C are hydrophobic, and microcalorimetric data reveals that the small amount of adsorption observed arises from either chemical or physical adsorption rather than condensation. Hydrophobic carbon surfaces subsequently oxygenated at 150 degrees C showed significant increases in the amount of water adsorbed through physical adsorption. These results demonstrate that microcalorimetric techniques complement standard isotherm measurements in describing the nature of water adsorption on carbon surfaces. C1 Univ Calif Los Alamos Natl Lab, Engn Sci & Applicat Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Penn State Univ, Dept Energy & Geoenvironm Engn, University Pk, PA 16802 USA. Penn State Univ, Dept Chem Engn, University Pk, PA 16802 USA. RP Phillips, J (reprint author), Univ Calif Los Alamos Natl Lab, Engn Sci & Applicat Div, MS C930, Los Alamos, NM 87545 USA. RI Phillips, Jonathan/D-3760-2011 NR 35 TC 25 Z9 25 U1 1 U2 18 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 31 PY 2000 VL 104 IS 34 BP 8170 EP 8176 DI 10.1021/jp994270j PG 7 WC Chemistry, Physical SC Chemistry GA 349WJ UT WOS:000089068300012 ER PT J AU Williford, RE Windisch, CF Jones, RH AF Williford, RE Windisch, CF Jones, RH TI In situ observations of the early stages of localized corrosion in Type 304 SS using the electrochemical atomic force microscope SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE corrosion; Type 304 SS; electrochemical atomic force microscope; pitting; intergranular corrosion ID SCANNING-TUNNELING-MICROSCOPY; STAINLESS-STEEL; BEHAVIOR; SURFACE AB In situ. time-lapse images of the early stages of pitting in dilute NaCl solutions, and intergranular corrosion in dilute oxalic acid solutions, have been obtained in Type 304 SS (UNS S30400) using an electrochemical atomic force microscope (ECAFM). A pit was observed to grow from an irregular shape with ledges along the pit walls, to a round pit with an island formation. over a 6-min time span. Grain boundary chromium carbides were exposed, and then partially dissolved, over a 26-min time span. The intergranular corrosion was most prominent along the grain boundary between the carbides, rather than between the carbides and the matrix, leaving the carbides intact via ligaments of matrix material. This study demonstrated the usefulness and complexities in using the ECAFM for studying the early stages in pitting and intergranular corrosion. Published by Elsevier Science S.A. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Jones, RH (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 16 TC 32 Z9 38 U1 1 U2 15 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD AUG 31 PY 2000 VL 288 IS 1 BP 54 EP 60 DI 10.1016/S0921-5093(00)00883-2 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 336NV UT WOS:000088310200009 ER PT J AU Dai, PC Mook, HA Aeppli, G Hayden, SM Dogan, F AF Dai, PC Mook, HA Aeppli, G Hayden, SM Dogan, F TI Resonance as a measure of pairing correlations in the high-T-c superconductor YBa2Cu3O6.6 SO NATURE LA English DT Article ID NEUTRON-SCATTERING; SPIN FLUCTUATIONS; MECHANISM; MODEL; ANTIFERROMAGNETISM; SPECTRA; STATE; GAP AB One of the most striking properties of the high-transition-temperature (high-T-c) superconductors is that they are all derived from insulating antiferromagnetic parent compounds. The intimate relationship between magnetism and superconductivity in these copper oxide materials has intrigued researchers from the outset(1-4), because it does not exist in conventional superconductors. Evidence for this link comes from neutron-scattering experiments that show the unambiguous presence of short-range antiferromagnetic correlations (excitations) in the high-T-c superconductors. Even so, the role of such excitations in the pairing mechanism for superconductivity is still a subject of controversy(5). For YBa2Cu3O6+x, where x controls the hole-doping level, the most prominent feature in the magnetic excitation spectrum is a sharp resonance (refs 6-11). Here we show that for underdoped YBa2Cu3O6.6, where x and T-c are below their optimal values, modest magnetic fields suppress the resonance significantly, much more so for fields approximately perpendicular to the CuO2 planes than for parallel fields. Our results indicate that the resonance measures pairing and phase coherence, suggesting that magnetism plays an important role in high-T-c superconductivity. The persistence of a field effect above T-c favours mechanisms in which the superconducting electron pairs are pre-formed in the normal state of underdoped copper oxide superconductors(12-14), awaiting transition to the superconducting state. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NEC Res Inst, Princeton, NJ 08540 USA. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Univ Washington, Dept Mat Sci & Engn, Seattle, WA 98195 USA. RP Dai, PC (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Hayden, Stephen/F-4162-2011; Dai, Pengcheng /C-9171-2012 OI Hayden, Stephen/0000-0002-3209-027X; Dai, Pengcheng /0000-0002-6088-3170 NR 31 TC 149 Z9 149 U1 0 U2 11 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 31 PY 2000 VL 406 IS 6799 BP 965 EP 968 DI 10.1038/35023094 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 348ZW UT WOS:000089020200036 ER PT J AU Schieber, J Krinsley, D Riciputi, L AF Schieber, J Krinsley, D Riciputi, L TI Diagenetic origin of quartz silt in mudstones and implications for silica cycling SO NATURE LA English DT Article ID FOSSIL RECORD; PROVENANCE; DEPOSITION; MUDROCKS; ISOTOPES; OXYGEN AB Mudstone-the most abundant sedimentary rock type(1), composed primarily of clay- or silt-sized particles-contains most of the quartz found in sedimentary rocks(2). These quartz grains, which are chemically and mechanically resistant and therefore preserve their characteristics well, have long been considered to be derived from the continental crust(1). Here we analyse quartz silt from black shales in the eastern USA, dating back to the Late Devonian period (about 370 million years ago), using backscattered electron and cathodoluminescence imaging and measure oxygen isotopes with an ion probe. Our results indicate that up to 100% of the quartz silt in our samples does not originate from the continental crust. Instead, it appears to have precipitated early in diagenesis in algal cysts and other pore spaces(3), with silica derived from the dissolution of opaline skeletons of planktonic organisms, such as radiolaria and diatoms. Transformation of early diatoms into in situ quartz silt might explain the time gap between the earliest fossil occurrences of diatoms about 120 Myr ago(4) and molecular evidence for a much earlier appearance between 266 or even 500 Myr ago(5,6). Moreover, if many other mudstone successions show similarly high proportions of in situ precipitated-rather than detrital-quartz silt, the sedimentary record in mudstones may have been misinterpreted in the past, with consequences for our estimates of palaeoproductivity as well as our perceptions of the dynamics and magnitude of global biogeochemical cycling of silica. C1 Univ Texas, Dept Geol, Arlington, TX 76019 USA. Univ Oregon, Dept Geol Sci, Eugene, OR 97403 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Schieber, J (reprint author), Univ Texas, Dept Geol, Arlington, TX 76019 USA. RI Schieber, Juergen Schieber/A-3001-2013 NR 30 TC 53 Z9 58 U1 1 U2 12 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 31 PY 2000 VL 406 IS 6799 BP 981 EP 985 DI 10.1038/35023143 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 348ZW UT WOS:000089020200041 PM 10984049 ER PT J AU Kingon, AI Maria, JP Streiffer, SK AF Kingon, AI Maria, JP Streiffer, SK TI Alternative dielectrics to silicon dioxide for memory and logic devices SO NATURE LA English DT Review ID BA0.7SR0.3TIO3 THIN-FILMS; CHEMICAL-VAPOR-DEPOSITION; OXIDES; RELAXATION; CERAMICS AB The silicon-based microelectronics industry is rapidly approaching a point where device fabrication can no longer be simply scaled to progressively smaller sizes. Technological decisions must now be made that will substantially alter the directions along which silicon devices continue to develop. One such challenge is the need for higher permittivity dielectrics to replace silicon dioxide, the properties of which have hitherto been instrumental to the industry's success. Considerable efforts have already been made to develop replacement dielectrics for dynamic random-access memories. These developments serve to illustrate the magnitude of the now urgent problem of identifying alternatives to silicon dioxide for the gate dielectric in logic devices, such as the ubiquitous field-effect transistor. C1 N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Kingon, AI (reprint author), N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. RI Streiffer, Stephen/A-1756-2009 NR 37 TC 867 Z9 891 U1 12 U2 108 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 31 PY 2000 VL 406 IS 6799 BP 1032 EP 1038 DI 10.1038/35023243 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 348ZW UT WOS:000089020200055 ER PT J AU Barger, V Han, T Li, T Lykken, JD Marfatia, D AF Barger, V Han, T Li, T Lykken, JD Marfatia, D TI Cosmology and hierarchy in stabilized warped brane models SO PHYSICS LETTERS B LA English DT Article ID EXTRA DIMENSIONS; TEV; MILLIMETER; COLLIDERS; INFLATION; UNIVERSE; GRAVITY; SIGNALS AB We examine the cosmology and hierarchy of scales in models with branes immersed in a five-dimensional curved spacetime subject to radion stabilization. When the radion field is time-independent and the inter-brane spacing is stabilized, the universe can naturally find itself in the radiation-dominated epoch. This feature is independent of the form of the stabilizing potential. We recover the standard Friedmann equations without assuming a specific form for the bulk energy-momentum tensor. In the models considered, if the observable brane has positive tension, a solution to the hierarchy problem requires the presence of a negative tension brane somewhere in the bulk. We find that the string scale can be as low as the electroweak scale. In the situation of self-tuning branes where the bulk cosmological constant is set to zero, the brane tensions have hierarchical values. In the case of a polynomial stabilizing potential no new hierarchy is created. (C) 2000 Published by Elsevier Science B.V. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Fermi Natl Accelerator Lab, Theory Grp, Batavia, IL 60510 USA. RP Barger, V (reprint author), Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. OI Han, Tao/0000-0002-5543-0716 NR 55 TC 28 Z9 28 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 31 PY 2000 VL 488 IS 2 BP 97 EP 107 DI 10.1016/S0370-2693(00)00877-7 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 352KC UT WOS:000089213200001 ER PT J AU Kuprat, A AF Kuprat, A TI Modeling microstructure evolution using gradient-weighted moving finite elements SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE microstructure evolution; motion by mean curvature; gradient-weighted moving; finite elements; unstructured tetrahedral meshes; deforming grids; hanging grid topology; front-tracking ID MULTIPHASE MOTION; GRAIN-GROWTH; DESIGN AB Microstructure evolution, where grain boundaries evolve by mean curvature motion, is modeled in three dimensions (3-D) using gradient-weighted moving finite elements ( GWMFE). To do this, we modify and extend an existing 2-D GWMFE ode to create a new code GRAIN3D which makes the 3-D microstructure modeling possible. The right-hand side term which drives the GWMFE motion can be viewed as surface tension forces, that is, as the negative gradient of the surface integral of a constant energy density mu on the triangular interfacial grid. Extensions to the method include equations for the motion of tetrahedra that are conformally attached to the moving piecewise linear triangular facets which represent the GWMFE discretization of the evolving grain boundaries. We present some new regularization terms which control element quality, as well as preventing element collapse in the simulation. New capabilities for hanging the mesh topology are used to keep the grid edge lengths below a maximum allowable length h(max) and to mimic actual changes in the physical topology, such as collapse and disappearance of individual grains. Validating runs are performed on some test cases that can be analytically solved, including collapse of a spherical grain and the case of columnar microstructure. In the spherical collapse case, the GWMFE method appears to have an error in the surface area collapse rate -dA/dt which is O((Delta theta)(2)), where Delta theta is a measure of the angular resolution of the mesh. Finally, a run is presented where a true 3-D microstructure ( possessing triple lines and quadruple points in the interior and triple points on the exterior boundaries) is evolved to a 2-D columnar microstructure and finally evolved down to a single grain. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Grp T1, Los Alamos, NM 87545 USA. RP Kuprat, A (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Grp T1, Mailstop B-221, Los Alamos, NM 87545 USA. OI Kuprat, Andrew/0000-0003-4159-918X NR 25 TC 31 Z9 31 U1 1 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD AUG 31 PY 2000 VL 22 IS 2 BP 535 EP 560 DI 10.1137/S1064827598348374 PG 26 WC Mathematics, Applied SC Mathematics GA 349VA UT WOS:000089065200008 ER PT J AU Levy, D Puppo, G Russo, G AF Levy, D Puppo, G Russo, G TI Compact central WENO schemes for multidimensional conservation laws SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE hyperbolic systems; central difference schemes; high-order accuracy; nonoscillatory schemes; WENO reconstruction; CWENO reconstruction ID SHOCK-CAPTURING SCHEMES; ORDER CENTRAL SCHEMES; HYPERBOLIC SYSTEMS; EFFICIENT IMPLEMENTATION AB We present a new third-order central scheme for approximating solutions of systems of conservation laws in one and two space dimensions. In the spirit of Godunov-type schemes, our method is based on reconstructing a piecewise-polynomial interpolant from cell-averages which is then advanced exactly in time. In the reconstruction step, we introduce a new third-order, compact, central weighted essentially nonoscillatory (CWENO) reconstruction, which is written as a convex combination of interpolants based on different stencils. The heart of the matter is that one of these interpolants is taken as a suitable quadratic polynomial, and the weights of the convex combination are set as to obtain third-order accuracy in smooth regions. The embedded mechanism in the WENO-like schemes guarantees that in regions with discontinuities or large gradients, there is an automatic switch to a one-sided second-order reconstruction, which prevents the creation of spurious oscillations. In the one-dimensional case, our new third-order reconstruction is based on an extremely compact three-point stencil. Analogous compactness is retained in more space dimensions. The accuracy, robustness, and high-resolution properties of our scheme are demonstrated in a variety of one- and two-dimensional problems. C1 Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA USA. Politecn Torino, Dipartimento Matemat, I-10129 Turin, Italy. Univ Aquila, Dipartimento Matemat, I-67100 Laquila, Italy. RP Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. EM dlevy@math.berkeley.edu; puppo@calvino.polito.it; russo@univaq.it RI Russo, Giovanni/B-7097-2016 OI Russo, Giovanni/0000-0003-4215-1926 NR 26 TC 95 Z9 104 U1 2 U2 17 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 EI 1095-7197 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD AUG 31 PY 2000 VL 22 IS 2 BP 656 EP 672 DI 10.1137/S1064827599359461 PG 17 WC Mathematics, Applied SC Mathematics GA 349VA UT WOS:000089065200014 ER PT J AU Pattabi, M Sebastian, PJ Mathew, X Bhattacharya, RN AF Pattabi, M Sebastian, PJ Mathew, X Bhattacharya, RN TI Preparation and characterization of copper indium diselenide films by electroless deposition SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE CuInSe(2); electroless deposition; thin films; polycrystalline solar cells ID THIN-FILMS; ELECTRODEPOSITION; CIS AB The preparation of copper indium diselenide (CIS) films by electroless deposition technique is reported. The films have been deposited on molybdenum substrates. The deposition bath consisted of aqueous solutions of copper chloride, indium chloride, selenous acid and lithium chloride. The pH of the bath was adjusted to 2.2 by adding dilute HCl. The Mo substrate was short-circuited with the aluminum counter electrode for the electroless deposition. The films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDXA), inductively coupled plasma spectroscopy (ICP), Auger electron spectroscopy (AES) and optical spectroscopy. The results indicate that reasonable quality CIS films can be grown by simple electroless deposition process followed by recrystallization in selenium atmosphere. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Energy Res Ctr, Solar Hydrogen Fuel Cell Grp, Temixco 62580, Morelos, Mexico. NREL, Golden, CO USA. Mangalore Univ, Dept Mat Sci, Mangalagangothri 574199, India. RP Pattabi, M (reprint author), Univ Nacl Autonoma Mexico, Energy Res Ctr, Solar Hydrogen Fuel Cell Grp, Temixco 62580, Morelos, Mexico. EM manjupattabi@hotmail.com NR 11 TC 15 Z9 15 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOL ENERG MAT SOL C JI Sol. Energy Mater. Sol. Cells PD AUG 31 PY 2000 VL 63 IS 4 BP 315 EP 323 DI 10.1016/S0927-0248(00)00051-9 PG 9 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 350HR UT WOS:000089095600003 ER PT J AU Bhattacharya, RN Batchelor, W Ramanathan, K Contreras, MA Moriarty, T AF Bhattacharya, RN Batchelor, W Ramanathan, K Contreras, MA Moriarty, T TI The performance of CuIn1-xGaxSe2-based photovoltaic cells prepared from low-cost precursor films SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE CuIn1-xGaxSe2; electrodeposition; electroless deposition; solar cells AB In this paper we report the 15.4%- and 13.4%-efficient CuIn1-xGaxSe2 (CIGS)-based devices from electrodeposited (ED) and electroless deposited (EL) precursors. The efficiency of the device prepared from electroless precursor film has been improved from 12.4% to 13.4%. The dependence of quantum efficiencies on reverse-bias voltage has been measured for a 15.4%-efficient ED device, 18.8%-efficient physical-vapor-deposited device, and 14.2%-efficient Cd-free device. The purpose of this work is to explore and improve the current collection mechanism. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Bhattacharya, RN (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 7 TC 26 Z9 30 U1 3 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOL ENERG MAT SOL C JI Sol. Energy Mater. Sol. Cells PD AUG 31 PY 2000 VL 63 IS 4 BP 367 EP 374 DI 10.1016/S0927-0248(00)00056-8 PG 8 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 350HR UT WOS:000089095600008 ER PT J AU Zweibel, K AF Zweibel, K TI Thin film PV manufacturing: Materials costs and their optimization SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE photovoltaics; thin films; copper indium diselenide; cadmium telluride; amorphous silicon; thin film silicon; manufacturing costs; materials costs AB Thin film PV technologies face a number of hurdles as they advance towards low-cost goals that would make them competitive with traditional sources of electricity. The US Department of Energy cost goal for thin films is about $0.33/W-p, which corresponds to module efficiencies of about 15% and module manufacturing costs of about $50/m(2). Past papers have provided a framework for examining thin film efficiencies and manufacturing costs, especially those costs for equipment, labor, materials, utilities, and others. Although materials costs appear to be a large fraction of the total, we have not yet broken them down in enough detail to seek significant improvement. In the future, with more mature thin him production, materials costs such as those from semiconductor layers, contacts, pottants, substrates, and electrical interconnection will dominate total module cost. This paper (1) breaks down the materials costs into two broad categories (active and inactive materials) and then (2) investigates the issues associated with reducing their costs much below today's levels. Materials will likely be such an overwhelming cost-driver for mature manufacturing of thin him PV that issues associated with their optimization should be examined as soon as possible in order to meet the DOE long-term goals for PV module costs. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Thin Film PV Partnership, Golden, CO 80401 USA. RP Zweibel, K (reprint author), Natl Renewable Energy Lab, Thin Film PV Partnership, 1617 Cole Blvd, Golden, CO 80401 USA. NR 14 TC 70 Z9 70 U1 0 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOL ENERG MAT SOL C JI Sol. Energy Mater. Sol. Cells PD AUG 31 PY 2000 VL 63 IS 4 BP 375 EP 386 DI 10.1016/S0927-0248(00)00057-X PG 12 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 350HR UT WOS:000089095600009 ER PT J AU Betancourt, FMH Glaeser, RM AF Betancourt, FMH Glaeser, RM TI Chemical and physical evidence for multiple functional steps comprising the M state of the bacteriorhodopsin photocycle SO BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS LA English DT Review DE bacteriorhodopsin; ion transport; M intermediate; photocycle; protein dynamics ID X-RAY-DIFFRACTION; DRIVEN PROTON PUMP; INFRARED DIFFERENCE SPECTROSCOPY; PURPLE MEMBRANE; HALOBACTERIUM-HALOBIUM; M-INTERMEDIATE; STRUCTURAL-CHANGES; RESONANCE RAMAN; SCHIFF-BASE; CONFORMATIONAL-CHANGES AB In the photocycle of bacteriorhodopsin (bR), light-induced transfer of a proton from the Schiff base to an acceptor group located in the extracellular half of the protein, followed by reprotonation from the cytoplasmic side, are key steps in vectorial proton pumping. Between the deprotonation and reprotonation events, bR is in the M state. Diverse experiments undertaken to characterize the M state support a model in which the M state is not a static entity, but rather a progression of two or more functional substates. Structural changes occurring in the M state and in the entire photocycle of wild-type bR call be understood in the context of a model which reconciles the chloride ion-pumping phenotype of mutants D85S and D85T with the fact that bR creates a transmembrane proton-motive force. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Stanley Donner ASU, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. RP Betancourt, FMH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Div Life Sci, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM51487] NR 90 TC 31 Z9 31 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0005-2728 J9 BBA-BIOENERGETICS JI Biochim. Biophys. Acta-Bioenerg. PD AUG 30 PY 2000 VL 1460 IS 1 SI SI BP 106 EP 118 DI 10.1016/S0005-2728(00)00133-X PG 13 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 353TG UT WOS:000089291100010 PM 10984594 ER PT J AU Sturm, ME Goldstein, SJ Klein, EM Karson, JA Murrell, MT AF Sturm, ME Goldstein, SJ Klein, EM Karson, JA Murrell, MT TI Uranium-series age constraints on lavas from the axial valley of the Mid-Atlantic Ridge, MARK area SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Mid-Atlantic Ridge; mid-ocean ridge basalts; uranium disequilibrium; lava flows ID EAST PACIFIC RISE; RA-226 TH-230 DISEQUILIBRIUM; HYDROTHERMAL PROCESSES; VOLCANIC PROCESSES; MIDOCEAN RIDGES; BASALTS; CHRONOLOGY; CRUST; MORB AB Mass spectrometric measurements of Th-230-Ra-226, U-235-Pa-231 and U-238-Th-230 disequilibria are used to determine eruption ages for four mid-ocean ridge basalts from the median valley of the Mid-Atlantic Ridge south of the Kane Fracture Zone (MARK area). Three samples were collected across-axis on the Axial Volcanic Ridge (i.e. the Neovolcanic Ridge) near the Snake Pit hydrothermal mound, and one sample was collected near the crest of Serocki Volcano similar to 50 km south of Snake Pit. (Ra-226)/(Th-230) and (Th-230)/(U-238) activity ratios are low and uniform for all four samples, while (Pa-233)/(U-235) activity ratios are elevated and somewhat more variable. Age constraints suggest that these lavas, from the most robust volcanic edifices in the MARK area, are 10 000-20 000 yr old. The age data are used to evaluate the efficacy of commonly used age estimate scales based on qualitative indicators (e.g. sediment cover, glass quality) and to begin to quantify the temporal and spatial dependence of volcanic, tectonic and hydrothermal processes at slow-spreading oceanic ridges. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Duke Univ, Nicholas Sch Environm, Div Earth & Ocean Sci, Durham, NC 27708 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Klein, EM (reprint author), Duke Univ, Nicholas Sch Environm, Div Earth & Ocean Sci, Durham, NC 27708 USA. NR 37 TC 28 Z9 29 U1 0 U2 2 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 AUG 30 PY 2000 VL 181 IS 1-2 BP 61 EP 70 DI 10.1016/S0012-821X(00)00177-1 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 353QN UT WOS:000089287100007 ER PT J AU Lee, WH Lyczkowski, RW AF Lee, WH Lyczkowski, RW TI The basic character of five two-phase flow model equation sets SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE batch settling; fluidized bed; ill-posed PDEs; jet impingement; two-phase models; well-posed PDEs AB Three test problems were simulated using five different two-phase flow model equation sets from the open literature. The test problems chosen were a fluidized bed, a batch settling, and a horizontal jet impingement on a vertical wall. These three problems demonstrate an important cross-section of physical phenomena, such as fluidized bed voidage oscillations, phase separation, countercurrent flow, and jet formation. The dispersed now regime is selected for all three problems. The study was performed to assess the basic character of the five-field equation sets responding to the same initial and boundary conditions and using the same finite difference numerical scheme. The general performance of the five equation sets was found to be similar, even though one of them was ill posed as an initial-value problem. Broad trends are the same and quantitative differences could be assessed by examining the fine structure of the results. None of the equation sets could be entirely rejected on the basis of producing physically impossible or unacceptable results. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Lyczkowski, RW (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 19 TC 15 Z9 17 U1 2 U2 7 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD AUG 30 PY 2000 VL 33 IS 8 BP 1075 EP 1098 DI 10.1002/1097-0363(20000830)33:8<1075::AID-FLD43>3.0.CO;2-5 PG 24 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA 346XK UT WOS:000088896200001 ER PT J AU Liang, L Shi, MK Viswanathan, VV Peurrung, LM Young, JS AF Liang, L Shi, MK Viswanathan, VV Peurrung, LM Young, JS TI Temperature-sensitive polypropylene membranes prepared by plasma polymerization SO JOURNAL OF MEMBRANE SCIENCE LA English DT Article DE composite membrane; plasma polymerized membrane; microporous and porous membranes; poly-N-isopropylacrylamide; temperature sensitive polymers ID N-ISOPROPYLACRYLAMIDE; SURFACE; PERMEATION; POLY(N-ISOPROPYLACRYLAMIDE); PHOTOPOLYMERIZATION; PERMEABILITY; RELEASE AB Poly-N-isopropylacylamide (PNIPAAm) was grafted on polypropylene (PP) microfiltration membranes using plasma polymerization. The surface of the grafted membrane was evaluated by Fourier transform infrared (FTIR) spectroscopy. Scanning electron microscopy pictures demonstrated that the PNIPAAm can be grafted either on the surface or in the pores of the membrane. The morphology of the grafted membrane can be adjusted through monomer concentration and polymerization time. Surface properties with a reversible response to temperature change were observed by measuring the dynamic contact angle. Below the low critical soluble temperature (LCST) of PNIPAAm, the grafted PP membrane exhibited a hydrophilic surface (advancing contact angle<40 degrees). Above the LCST, the surface changed to hydrophobic properties (advancing contact angle>90 degrees). We investigated the on-off characteristics of the grafted membrane by measuring water flux through the grafted membrane at different temperatures. The water flux can be varied from 25 to 7500 kg/m(2) h, depending on the temperature and pressure drop. The swelling PNIPAAm chains block the pores of the microfiltration membrane, and the flux decreases (off status). The PNIPAAm chains shrink above the LCST and open the pores of the microfiltration membrane. Thus, the water flux increases (on status). The effect of pressure drop on the water flux of the grafted PP membrane was discussed. The rapid and remarkable changes in the pore size of the membrane may make it possible to use the grafted PP membranes as the carrier for a drug-delivery system. They would also be used as multifunctional separation membranes, control valves, and actuators. Published by Elsevier Science B.V. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Liang, L (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd,POB 999, Richland, WA 99352 USA. NR 30 TC 66 Z9 74 U1 4 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0376-7388 J9 J MEMBRANE SCI JI J. Membr. Sci. PD AUG 30 PY 2000 VL 177 IS 1-2 BP 97 EP 108 DI 10.1016/S0376-7388(00)00453-1 PG 12 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 346RY UT WOS:000088885900011 ER PT J AU Wang, XB Broadus, KM Wang, LS Kass, SR AF Wang, XB Broadus, KM Wang, LS Kass, SR TI Photodetachment of the first zwitterionic anions in the gas phase: Probing intramolecular Coulomb repulsion and attraction SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHOTOELECTRON-SPECTROSCOPY; DISSOCIATION; IONIZATION C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. RP Wang, LS (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99352 USA. NR 24 TC 15 Z9 15 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 30 PY 2000 VL 122 IS 34 BP 8305 EP 8306 DI 10.1021/ja001943z PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 353XW UT WOS:000089301600027 ER PT J AU George, GN Pickering, IJ Yu, EY Prince, RC Bursakov, SA Gavel, OY Moura, I Moura, JJG AF George, GN Pickering, IJ Yu, EY Prince, RC Bursakov, SA Gavel, OY Moura, I Moura, JJG TI A novel protein-bound copper - Molybdenum cluster SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RAY-ABSORPTION SPECTROSCOPY; SULFITE OXIDASE; SITE; CLEAVAGE; COMPLEX; ENZYMES C1 Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. ExxonMobil Res & Engn Co, Annandale, NJ 08801 USA. Univ Nova Lisboa, Fac Ciencias & Tecnol, Dept Quim, Ctr Quim Fina & Biotecnol, P-2825 Monte De Caparica, Portugal. RP George, GN (reprint author), Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, POB 20450,MS 69, Stanford, CA 94309 USA. RI Moura, Jose/D-6426-2013; George, Graham/E-3290-2013; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013; Pickering, Ingrid/A-4547-2013; OI Moura, Jose/0000-0002-4726-2388; Moura, Isabel/0000-0003-0971-4977; Prince, Roger/0000-0002-5174-4216 NR 20 TC 72 Z9 72 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 30 PY 2000 VL 122 IS 34 BP 8321 EP 8322 DI 10.1021/ja000955h PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 353XW UT WOS:000089301600035 ER PT J AU Cappelli, E Degan, P Thompson, LH Frosina, G AF Cappelli, E Degan, P Thompson, LH Frosina, G TI Efficient repair of 8-oxo-7,8-dihydrodeoxyguanosine in human and hamster xeroderma pigmentosum D cells SO BIOCHEMISTRY LA English DT Article ID BASE EXCISION-REPAIR; OXIDATIVE DNA-DAMAGE; MAMMALIAN-CELLS; GENE; GLYCOSYLASE; 8-HYDROXY-2'-DEOXYGUANOSINE; NEURODEGENERATION; TRANSCRIPTION; 8-OXOGUANINE; MUTATIONS AB The repair of the endogenous lesion 8-oxo-7,8-dihydrodeoxyguanosine (8-oxodG) was investigated in the nucleotide excision repair mutant xeroderma pigmentosum D (XPB), using human normal or transformed XPD fibroblasts and the Chinese hamster XPD cell line UV5. In vivo repair of 8-oxodG induced by hydrogen peroxide treatment and analyzed by high-performance liquid chromatography/electrochemical detection was normal in the XPD mutant fibroblasts XP15PV and GM434, as compared to normal human fibroblasts GR 1970, GM15757, and GM6114. Similar results were obtained with the human SV40-transformed XPD mutant cell line GM8207 in comparison to the control cell line GM637. Repair of 8-oxodG was even slightly (2-3-fold) but reproducibly increased in Chinese hamster XPD mutant UV5 cells, as compared to parental AA8 cells. This unexpected effect was reversed by transfection in UV5 cells of a wild-type XPD cDNA and confirmed in in vitro experiments in which a plasmid substrate containing a single 8-oxoG was repaired by UV5 cell extracts. The data show that repair of 8-oxodG is normal in XPD cells, thus indicating that the neurological complications of XPD patients may not be Linked to in vivo accumulation of this lesion. C1 Ist Nazl Ric Canc, Mutagenesis Lab, DNA Repair Unit, I-16132 Genoa, Italy. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Frosina, G (reprint author), Ist Nazl Ric Canc, Mutagenesis Lab, DNA Repair Unit, Largo Rosanna Benzi 10, I-16132 Genoa, Italy. RI Cappelli, Enrico/K-7954-2016 OI Cappelli, Enrico/0000-0001-5910-9260 FU Telethon [E.0728] NR 28 TC 6 Z9 6 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD AUG 29 PY 2000 VL 39 IS 34 BP 10408 EP 10412 DI 10.1021/bi992610l PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 349VQ UT WOS:000089066600007 PM 10956030 ER PT J AU Hlavacek, WS Stilianakis, NI Perelson, AS AF Hlavacek, WS Stilianakis, NI Perelson, AS TI Influence of follicular dendritic cells on HIV dynamics SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES LA English DT Article DE human immunodeficiency virus type 1; follicular dendritic cells; antiretroviral therapy ID IMMUNODEFICIENCY-VIRUS TYPE-1; ANTIRETROVIRAL THERAPY; LYMPHOID-TISSUES; IN-VIVO; ASYMPTOMATIC PATIENTS; COMBINATION THERAPY; POPULATION-DYNAMICS; VIRAL LOAD; INFECTION; COMPLEMENT AB In patients infected with human immunodeficiency virus type 1 (HIV-1), a large amount of virus is associated with follicular dendritic cells (FDCs) in lymphoid tissue. To assess the influence of FDCs on viral dynamics during antiretroviral therapy we have de developed a mathematical model for treatment of HIV-1 infection that includes FDCs. Here, we use this model to analyse measurements of HIV-1 dynamics in the blood and lymphoid tissue of a representative patient, who was treated with a combination of HIV-I reverse transcriptase and protease inhibitors. We show that loss of virus from FDCs during therapy can make a much larger contribution to plasma virus than production of virus by infected cells. This result challenges the notion that long-lived infected cells are a significant source of HIV-I during drug therapy Due to release of FDC-associated virus, we find that it is necessary to revise upward previous estimates of c, the rate at which free virus is cleared, and delta, the rate at which productively infected cells die. Furthermore, we find that potentially infectious virus, present before treatment, is released from FDCs during therapy and that the persistence of this virus can be affected by whether therapy includes reverse transcriptase inhibitors. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Erlangen Nurnberg, Dept Med Informat Biometry & Epidemiol, D-91054 Erlangen, Germany. RP Perelson, AS (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. FU NCRR NIH HHS [RR06555]; NIAID NIH HHS [AI28433] NR 49 TC 14 Z9 14 U1 0 U2 1 PU ROYAL SOC LONDON PI LONDON PA 6 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8436 J9 PHILOS T ROY SOC B JI Philos. Trans. R. Soc. Lond. Ser. B-Biol. Sci. PD AUG 29 PY 2000 VL 355 IS 1400 BP 1051 EP 1058 PG 8 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 354WV UT WOS:000089354600007 PM 11186306 ER PT J AU Barenblatt, GI Bertsch, M Chertock, AE Prostokishin, VM AF Barenblatt, GI Bertsch, M Chertock, AE Prostokishin, VM TI Self-similar intermediate asymptotics for a degenerate parabolic filtration-absorption equation SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID DIFFUSION AB The equation partial derivative(t)u= u partial derivative(xx)(2)u-(c-1)(partial derivative(x)u)(2) is known in literature as a qualitative mathematical model of some biological phenomena. Here this equation is derived as a model of the groundwater flow in a water-absorbing fissurized porous rock; therefore, we refer to this equation as a filtration-absorption equation. A family of self-similar solutions to this equation is constructed. Numerical investigation of the evolution of non-self-similar solutions to the Cauchy problems having compactly supported initial conditions is performed. Numerical experiments indicate that the self-similar solutions obtained represent intermediate asymptotics of a wider class of solutions when the influence of details of the initial conditions disappears but the solution is still far from the ultimate state: identical zero. An open problem caused by the nonuniqueness of the solution of the Cauchy problem is discussed. C1 Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Roma Tor Vergata, Dept Math, I-00133 Rome, Italy. Russian Acad Sci, PP Shirshov Oceanol Inst, Moscow 117218, Russia. RP Barenblatt, GI (reprint author), Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. RI Chertock, Alina/I-3676-2013; OI Chertock, Alina/0000-0003-4978-1314; Prostokishin, Valeriy/0000-0001-6185-9642 NR 15 TC 31 Z9 32 U1 0 U2 6 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD AUG 29 PY 2000 VL 97 IS 18 BP 9844 EP 9848 DI 10.1073/pnas.97.18.9844 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 349WA UT WOS:000089067500008 PM 10963657 ER PT J AU Schroeder, BR Meng, S Bostwick, A Olmstead, MA Rotenberg, E AF Schroeder, BR Meng, S Bostwick, A Olmstead, MA Rotenberg, E TI Epitaxial growth of laminar crystalline silicon on CaF2 SO APPLIED PHYSICS LETTERS LA English DT Article ID INTERFACE; CAF2/SI(111); MORPHOLOGY; INSULATOR; SI(111); SI; HETEROEPITAXY; SEMICONDUCTOR; DIFFRACTION; KINETICS AB Si heteroepitaxy on CaF2 was studied with x-ray photoelectron spectroscopy and diffraction and low-energy electron diffraction to determine the interface bonding and silicon overlayer growth mode. The CaF2 surface was prepared by irradiation with low-energy electrons and exposure to arsenic, which replaced surface fluorine atoms with arsenic. Thin Si films (1.3 nm) were subsequently deposited at 550 degrees C. The Si films completely cover the CaF2 substrate and have a type-B orientation. The resultant interface has Si-Ca bonds, with the As surfactant layer terminating the Si surface in a 1x1 structure. (C) 2000 American Institute of Physics. [S0003-6951(00)02935-1]. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Schroeder, BR (reprint author), Univ Washington, Dept Phys, POB 351560, Seattle, WA 98195 USA. EM bretts@u.washington.edu RI Rotenberg, Eli/B-3700-2009; Bostwick, Aaron/E-8549-2010; OI Rotenberg, Eli/0000-0002-3979-8844; Olmstead, Marjorie/0000-0003-4374-0976 NR 23 TC 14 Z9 14 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 28 PY 2000 VL 77 IS 9 BP 1289 EP 1291 AR PII [S0003-6951(00)02935-1] DI 10.1063/1.1290158 PG 3 WC Physics, Applied SC Physics GA 346ZC UT WOS:000088900900017 ER PT J AU Ma, Q Moldovan, N Mancini, DC Rosenberg, RA AF Ma, Q Moldovan, N Mancini, DC Rosenberg, RA TI Sample size effect in photoelectrochemical etching of n-GaAs SO APPLIED PHYSICS LETTERS LA English DT Article AB A sample size effect on the etching rate in the photoelectrochemical etching of n-GaAs is demonstrated using synchrotron radiation x rays as the light source. It is shown that the etching rate increases significantly with the ratio of sample size to x-ray illuminated area. The rate-limiting effect on the charge transfer across the semiconductor-electrolyte junction is found to account for the phenomenon. It is also found that the etching rate relates to the nonilluminated area with a rather simple function. (C) 2000 American Institute of Physics. [S0003- 6951(00)00735-X]. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Ma, Q (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Rosenberg, Richard/K-3442-2012 NR 11 TC 4 Z9 4 U1 0 U2 4 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 AUG 28 PY 2000 VL 77 IS 9 BP 1319 EP 1321 DI 10.1063/1.1289908 PG 3 WC Physics, Applied SC Physics GA 346ZC UT WOS:000088900900027 ER PT J AU Ahoujja, M Yeo, YK Hengehold, RL Pomrenke, GS Look, DC Huffman, J AF Ahoujja, M Yeo, YK Hengehold, RL Pomrenke, GS Look, DC Huffman, J TI Electrical properties of boron-doped p-SiGeC grown on n(-)-Si substrate SO APPLIED PHYSICS LETTERS LA English DT Article ID MOBILITY; SILICON; CARBON; ALLOYS AB Electrical properties of fully strained boron-doped Si0.90-yGe0.10Cy/n(-)-Si grown by low pressure chemical vapor deposition have been investigated as a function of carbon content (0.2%-1.5%), using the variable temperature (25-650 K) Hall-effect technique. The results of Hall-effect measurements show that the Si substrate and the SiGeC/Si interfacial layer affect significantly the electrical properties of the SiGeC epitaxial layer. Thus, a three-layer conducting model has been used to extract the carrier concentration and mobility of the SiGeC layer alone. At room temperature, the hole carrier concentration decreases from 6.8x10(17) to 2.4x10(17) cm(-3) and the mobility decreases from 488 to 348 cm(2)/V s as the carbon concentration increases from 0.2% to 1.5%. The boron activation energy increases from 20 to 50 meV as C increases from 0.2% to 1.5% with an increment of 23 meV per atomic % of C. (C) 2000 American Institute of Physics. [S0003-6951(00)01835-0]. C1 USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. Natl Sci Fdn, Arlington, VA 22230 USA. Wright State Univ, Semicond Res Ctr, Dayton, OH 45435 USA. Lawrence Semicond Res Lab, Tempe, AZ 85282 USA. RP Ahoujja, M (reprint author), USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. NR 15 TC 10 Z9 10 U1 0 U2 1 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 AUG 28 PY 2000 VL 77 IS 9 BP 1327 EP 1329 AR PII [S0003-6951(00)01835-0] DI 10.1063/1.1290047 PG 3 WC Physics, Applied SC Physics GA 346ZC UT WOS:000088900900030 ER PT J AU Satula, W Wyss, R AF Satula, W Wyss, R TI A number projected model with generalized pairing interaction SO NUCLEAR PHYSICS A LA English DT Article ID NEUTRON-PROTON CORRELATIONS; TO-Z NUCLEI; ISOSPIN SYMMETRY; RICH NUCLEI; N=Z; T=0; ALIGNMENT; CR-48; RB-74 AB A mean-held model with a generalized pairing interaction that accounts for neutron-proton pairing is presented. Both the BCS as well as number-projected solutions of the model are presented. For the latter case the Lipkin-Nogami projection technique was extended to encompass the case of nonseparable proton-neutron systems. The influence of the projection on various pairing phases is discussed. In particular, it is shown that number-projection allows For mixing of different pairing phases but, simultanously, acts destructively on the proton-neutron correlations, The basic implications of proton-neutron pairing correlations on nuclear masses are discussed. It is shown that these correlations may provide a natural microscopic explanation of the Wigner energy lacking in mean-field models. A possible phase transition from isovector to isoscalar pairing condensate at high angular momenta is also discussed. In particular predictions for the dynamical moments of inertia for the superdeformed band in Ru-88 are given. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Warsaw, Inst Theoret Phys, PL-00681 Warsaw, Poland. Royal Inst Technol, Phys Dept Frescati, S-10405 Stockholm, Sweden. Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Kalmar Univ, Dept Technol, S-39129 Kalmar, Sweden. RP Satula, W (reprint author), Univ Warsaw, Inst Theoret Phys, Ul Hoza 69, PL-00681 Warsaw, Poland. NR 50 TC 71 Z9 71 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD AUG 28 PY 2000 VL 676 BP 120 EP 142 DI 10.1016/S0375-9474(00)00222-0 PG 23 WC Physics, Nuclear SC Physics GA 345DZ UT WOS:000088801300004 ER PT J AU Kogut, JB Stephanov, MA Toublan, D Verbaarschot, JJM Zhitnitsky, A AF Kogut, JB Stephanov, MA Toublan, D Verbaarschot, JJM Zhitnitsky, A TI QCD-like theories at finite baryon density SO NUCLEAR PHYSICS B LA English DT Article DE QCD partition function; finite baryon density; QCD with two colors; adjoint QCD; QCD Dirac operator; lattice QCD; low-energy effective theory; chiral perturbation theory ID CHIRAL PERTURBATION-THEORY; RANDOM-MATRIX THEORY; SPECTRAL SUM-RULES; SYMMETRY-BREAKING; DIRAC OPERATOR; GAUGE-THEORIES; SUPERCONDUCTIVITY; INSTANTONS; FERMIONS; ORIGIN AB We study QCD-like theories with pseudoreal fermions at finite baryon density. Such theories include two-color QCD with quarks in the fundamental representation of the color group as well as any-color QCD with quarks in the adjoint color representation. In all such theories the lightest baryons are diquarks, At zero chemical potential mu they are, together with the pseudoscalar mesons, the Goldstone modes of a spontaneously broken enlarged chiral symmetry group. Using symmetry principles, we derive the low-energy effective Lagrangian for these particles. We find that a second order phase transition occurs at a value of mu equal to half the mass of the Goldstone modes. For values of mu beyond this point the scalar diquarks Bose condense and the diquark condensate is nonzero. We calculate the dependence of the chiral condensate, the diquark condensate, the baryon charge density, and the masses of the diquark and pseudoscalar excitations on mu at finite bare quark mass and scaler diquark source. The relevance of our results to lattice QCD calculations and to real three-color QCD at finite baryon density is discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Loomis Lab Phys, Urbana, IL 61801 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. RP Univ Illinois, Loomis Lab Phys, 1110 W Green St, Urbana, IL 61801 USA. NR 51 TC 207 Z9 207 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD AUG 28 PY 2000 VL 582 IS 1-3 BP 477 EP 513 DI 10.1016/S0550-3213(00)00242-X PG 37 WC Physics, Particles & Fields SC Physics GA 347HD UT WOS:000088921600021 ER PT J AU Bogicevic, A Ovesson, S Hyldgaard, P Lundqvist, BI Brune, H Jennison, DR AF Bogicevic, A Ovesson, S Hyldgaard, P Lundqvist, BI Brune, H Jennison, DR TI Nature, strength, and consequences of indirect adsorbate interactions on metals SO PHYSICAL REVIEW LETTERS LA English DT Article ID SURFACE-DIFFUSION; MOLECULAR-DYNAMICS; ADATOM MOTION; NUCLEATION; AL(111); GROWTH; ATOMS; W(110) AB Atoms and molecules adsorbed on metals affect each other indirectly even over considerable distances. Via systematic density-functional calculations, we establish the nature and strength of such interactions, and explain for what adsorbate systems they critically affect important materials properties. This is verified in kinetic Monte Carlo simulations of epitaxial growth, which help rationalize a number of recent experimental reports on anomalously low diffusion prefactors. C1 Ford Res Lab, Dept Chem, Dearborn, MI 48121 USA. Chalmers, Dept Appl Phys, S-41296 Gothenburg, Sweden. Univ Gothenburg, S-41296 Gothenburg, Sweden. Ecole Polytech Fed Lausanne, Inst Phys Expt, CH-1015 Lausanne, Switzerland. Sandia Natl Labs, Surface & Interface Sci Dept, Albuquerque, NM 87185 USA. RP Ford Res Lab, Dept Chem, MD 3083 SRL, Dearborn, MI 48121 USA. EM abogicev@ford.com RI Lundqvist, Bengt/A-9013-2011; Hyldgaard, Per/A-2038-2011; Brune, Harald/E-7284-2017 OI Hyldgaard, Per/0000-0001-5810-8119; Brune, Harald/0000-0003-4459-3111 NR 38 TC 154 Z9 154 U1 3 U2 13 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 AUG 28 PY 2000 VL 85 IS 9 BP 1910 EP 1913 DI 10.1103/PhysRevLett.85.1910 PG 4 WC Physics, Multidisciplinary SC Physics GA 348BW UT WOS:000088965300033 ER PT J AU Bolton, SR Neukirch, U Sham, LJ Chemla, DS Axt, VM AF Bolton, SR Neukirch, U Sham, LJ Chemla, DS Axt, VM TI Demonstration of sixth-order coulomb correlations in a semiconductor single quantum well SO PHYSICAL REVIEW LETTERS LA English DT Article ID 4-WAVE-MIXING SIGNALS; EXCITONIC-MOLECULES; POLARIZATION; KINETICS; DYNAMICS; OPTICS; REGIME AB Six-wave mixing in a ZnSe quantum well is investigated and compared with microscopic theory. We demonstrate that sixth-order Coulomb correlations have a significant qualitative impact on the nonlinear optical response. Six-wave mixing is shown to be a uniquely sensitive tool for investigation of correlations beyond the four-point level. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Munster, Inst Theoret Phys, D-48149 Munster, Germany. Williams Coll, Dept Phys, Williamstown, MA 01267 USA. Univ Bremen, Inst Festkorperphys, D-28334 Bremen, Germany. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Bolton, SR (reprint author), Univ Calif Berkeley, Dept Phys, 1 Cyclotron Rd,MS 2-346, Berkeley, CA 94720 USA. RI Axt, Vollrath Martin/A-7688-2008; OI Sham, Lu/0000-0001-5718-2077 NR 29 TC 49 Z9 49 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 AUG 28 PY 2000 VL 85 IS 9 BP 2002 EP 2005 DI 10.1103/PhysRevLett.85.2002 PG 4 WC Physics, Multidisciplinary SC Physics GA 348BW UT WOS:000088965300056 ER PT J AU Zuelsdorf, RS Franz, RC Strangeway, RJ Russell, CT AF Zuelsdorf, RS Franz, RC Strangeway, RJ Russell, CT TI Determining the source of strong LF/VLF TIPP events: Implications for association with NPBPs and NNBPs SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TRANSIONOSPHERIC PULSE PAIRS; RADIATION AB Transionospheric pulse pairs (TIPPs) as detected by the Blackbeard VHF radio instrument onboard the ALEXIS satellite have been shown to correlate with pulses detected by stations in the National Lightning Detection Network (NLDN). The short peak-to-zero time of these NLDN-detected pulses (<10 mu s) are indicative of interior cloud processes, as opposed to the longer pulses associated with cloud-to-ground discharges. TIPPs are most probably generated by the same discharge responsible for narrow bipolar pulses (NBPs), which have been detected on the ground but are also believed to be generated entirely inside the cloud. Here we report on five TIPPs detected by Blackbeard that are correlated with cloud-generated pulses detected by multiple stations in the NLDN during powerful storms. Previously, a maximum of two stations at a time showed such a correlation. Given the greater area of detection, these pulses radiate more powerfully in the LF/VLF frequencies than those previously detected as TIPPs by Blackbeard. We are able to place the sources of the TIPPs in Hurricane Fausto off the coast of Mexico, and in a remnant of the same storm eight days later over Texas. The heights of the sources are higher than those previously determined for TIPPs. The higher altitudes and the greater power of the TIPP-correlating signals may be related to the intensity of the storms. Two of these five TIPPs were also correlated with the ground detection of HF signals, and the TIPPs and HF signals were determined to originate from the same source region. These HF signals are similar to those previously recorded with the field change signature of narrow positive bipolar pulses (NPBPs), but we find that both polarities are detected, four out of the five being negative. This indicates that TIPPs correlate with narrow negative bipolar pulses (NNBPs) as well as NPBPs. The detection of NNBPs, which has previously been much rarer than NPBPs, may also be related to the intensity of the storms and the resultant higher-altitude sources. C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Zuelsdorf, RS (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, 405 Hilgard Ave, Los Angeles, CA 90095 USA. EM strange@igpp.ucla.edu NR 18 TC 2 Z9 2 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 2000 VL 105 IS D16 BP 20725 EP 20736 DI 10.1029/2000JD900214 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 350NH UT WOS:000089107600020 ER PT J AU Furlanetto, MR Pivonka, NL Lenzer, T Neumark, DM AF Furlanetto, MR Pivonka, NL Lenzer, T Neumark, DM TI Vibrational spectroscopy of anions by stimulated Raman pumping-photoelectron spectroscopy SO CHEMICAL PHYSICS LETTERS LA English DT Article ID FLIGHT MASS-SPECTROMETER; NEGATIVE-IONS; PHOTODETACHMENT SPECTROSCOPY; INFRARED-SPECTRA; DETACHMENT; COMPLEXES; DYNAMICS; STATES; N-2 AB The first demonstration of a technique for the vibrational spectroscopy of anions, stimulated Raman pumping-anion photoelectron spectroscopy is reported. It combines the high spectral resolution of stimulated Raman pumping with the high detection efficiency, mass-selectivity, and wide applicability of anion photoelectron spectroscopy. The vibrational spectrum of a test system, C-2(-), is recorded and the frequency of the 1 <-- 0 vibrational transition is determined to be 1757.8 +/- 0.1 cm(-1). The Q-branch is partially rotationally resolved. (C) 2000 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Neumark, DM (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 28 TC 3 Z9 3 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 AUG 25 PY 2000 VL 326 IS 5-6 BP 439 EP 444 DI 10.1016/S0009-2614(00)00824-1 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 347GW UT WOS:000088920700012 ER PT J AU Nguyen, LH Erzberger, JP Root, J Wilson, DM AF Nguyen, LH Erzberger, JP Root, J Wilson, DM TI The human homolog of Escherichia coli orn degrades small single-stranded RNA and DNA oligomers SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID POLYMERASE-I; ACTIVE-SITE; AMINO-ACID; EXONUCLEASE; PROTEIN; OLIGORIBONUCLEASE; NUCLEUS; MOTIFS; DECAY; GENE AB We report here the identification of human homologues to the essential Escherichia coli Orn protein and the related yeast mitochondrial DNA-escape pathway regulatory factor Ynt20, The human proteins appear to arise from alternatively spliced transcripts, and are thus identical, except the human Ynt20 equivalent contains an NH2-terminal extension that possesses a predicted mitochondrial protease cleavage signal. In vitro analysis revealed that the smaller human protein exhibits a 3' to 5' exonuclease activity for small (primarily less than or equal to 5 nucleotides in length) single-stranded RNA and DNA oligomers, We have named this human protein Sfn for Small fragment nuclease to reflect its broad substrate range, and have termed the longer protein hSfn alpha. Sfn prefers Mn2+ as a metal cofactor and displays a temperature-resistant (to 50 degrees C) nuclease activity. Kinetic analysis indicates that Sfn exhibits a similar affinity for small RNAs and DNAs (K-m of similar to 1.5 mu M), but degrades small RNAs similar to 4-fold more efficiently than DNA, Mutation of a conserved aspartate (Asp(136)) to alanine abolishes both nuclease activities of Sfn, Northern blot analysis revealed that a l-kilobase transcript corresponding to SFN and/or SFN alpha (these mRNAs differ by only two nucleotides) is expressed at varying levels in all fetal and adult human tissues examined. Expressed tag sequence clone analysis found that the two splice variants, SFN to SFN alpha, are present at a ratio of roughly 4 to 1, respectively. The results presented within suggest a role for human Sfn in cellular nucleotide recycling. C1 Univ Calif Lawrence Livermore Natl Lab, Mol & Struct Biol Div, Livermore, CA 94551 USA. RP Wilson, DM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Mol & Struct Biol Div, Livermore, CA 94551 USA. FU NCI NIH HHS [CA79056] NR 27 TC 25 Z9 26 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD AUG 25 PY 2000 VL 275 IS 34 BP 25900 EP 25906 DI 10.1074/jbc.M002672200 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 348RF UT WOS:000088999700004 PM 10851236 ER PT J AU Miyabe, K Guiochon, G AF Miyabe, K Guiochon, G TI Determination of the lumped mass transfer rate coefficient by frontal analysis SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE mass transfer; frontal analysis; kinetic studies ID CONCENTRATION-DEPENDENCE; CELLULOSE TRIACETATE; LATERAL DIFFUSION; SURFACE-DIFFUSION; TRANSFER KINETICS; LIQUID-CHROMATOGRAPHY; LIGHT-SCATTERING; TROGERS BASE; PHASE; INTERFACE AB The validity of measurements of the lumped mass transfer rate coefficient (k(m,L)) is studied on the basis of experimental data acquired under Langmuir isotherm conditions, in reversed-phase liquid chromatography. Two different methods were used, the perturbation method and frontal analysis. Accurate values of k(m,L) can be properly obtained by the perturbation method because, with this method, the chromatographic processes take place under locally linear isotherm conditions. Values of k(m,L) can also be derived from the breakthrough curves obtained in frontal analysis. Because the contribution of axial dispersion to band broadening was larger than that of the mass transfer resistances, the apparent axial dispersion coefficient (D-a) was first derived from the breakthrough curve by applying the equilibrium-dispersive model. Then, the value of k(m,L) was calculated from D-a. The values of k(m,L) determined by the two methods were in close agreement in the range of nondimensional Langmuir equilibrium constants (r = 1/[1+KLC0]) between 0.32 and 0.85, irrespective of the mobile phase flow velocity. Thus, frontal analysis can be used for kinetic studies of the mass transfer in chromatographic columns. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 38 TC 33 Z9 35 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD AUG 25 PY 2000 VL 890 IS 2 BP 211 EP 223 DI 10.1016/S0021-9673(00)00537-9 PG 13 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 345TW UT WOS:000088832100002 PM 11009025 ER PT J AU Lawrence, DJ Feldman, WC Barraclough, BL Binder, AB Elphic, RC Maurice, S Miller, MC Prettyman, TH AF Lawrence, DJ Feldman, WC Barraclough, BL Binder, AB Elphic, RC Maurice, S Miller, MC Prettyman, TH TI Thorium abundances on the lunar surface SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID POLE AITKEN-BASIN; GAMMA-RAY; PROSPECTOR; ORIGIN; MANTLE; MOON AB Measurements of absolute thorium abundances on the lunar surface are presented using both the high- and low-altitude data taken with the Lunar Prospector Gamma-Ray Spectrometer. An analysis of the uncertainties shows that the measured uncertainties are < 0.5 mu g/g and are close to the theoretical limit of Poisson statistics. Currently, the overall systematic uncertainties are likely dominated by variations in background counts. The relative systematic uncertainties are thought to be no larger than 30% for the high-altitude data and 15% for the low-altitude data. A comparison of high- and low-altitude data show that most regions having thorium abundances > 7 mu g/g are likely small area regions less than or equal to (150 km)(2). Using lunar topographic data, we have shown that the thorium abundances in the lunar highlands and portions of South Pole-Aitken (SPA) Basin are larger for lower elevations. We have also studied a number of regions with anomalously high thorium abundances such as the northwestern region of SPA Basin, the crater Arago in western Tranquillitatis, and the Compton/Belkovich region in the northeastern highlands. The Compton/Belkovich region appears to be enriched with evolved rocks such as alkali anorthosite and currently represents the only such extended region on the Moon that has been identified. In contrast, Tycho crater has very low thorium abundances which suggests that KREEP was not assimilated at depth in this portion of the Moon. C1 Univ Calif Los Alamos Natl Lab, Grp NIS1, Los Alamos, NM 87545 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Lunar Res Inst, Tucson, AZ USA. RP Lawrence, DJ (reprint author), Univ Calif Los Alamos Natl Lab, Grp NIS1, MAil Stop D466, Los Alamos, NM 87545 USA. RI Lawrence, David/E-7463-2015; OI Lawrence, David/0000-0002-7696-6667; Prettyman, Thomas/0000-0003-0072-2831 NR 38 TC 132 Z9 147 U1 4 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD AUG 25 PY 2000 VL 105 IS E8 BP 20307 EP 20331 DI 10.1029/1999JE001177 PG 25 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348TY UT WOS:000089003600011 ER PT J AU Elphic, RC Lawrence, DJ Feldman, WC Barraclough, BL Maurice, S Binder, AB Lucey, PG AF Elphic, RC Lawrence, DJ Feldman, WC Barraclough, BL Maurice, S Binder, AB Lucey, PG TI Lunar rare earth element distribution and ramifications for FeO and TiO2: Lunar Prospector neutron spectrometer observations SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GAMMA-RAY; MOON; ABUNDANCES; FLUXES; ORIGIN; IRON AB Lunar Prospector neutron spectrometer data have been used to map the global surface distribution of the incompatible rare earth elements gadolinium and samarium from the low-altitude (30+/-15 km) mapping orbit. These results afford improved surface resolution and detailed views of the potassium, rare earth elements, and phosphorus (KREEP) distribution within and around Mare Imbrium and elsewhere. The Gd and Sm results serve as a complementary and independent check of the distribution of KREEP on the Moon, in contrast with the Lunar Prospector gamma ray spectrometer results for thorium, The neutron spectrometer observations reflect the presence of Fe and Ti as well as Gd and Sm, The contributions of Fe and Ti are removed using high spatial resolution Clementine spectral reflectance determinations of FeO and TiO2 abundances. Overall, the resulting Gd and Sm abundance map agrees with the Th abundance map determined using the Lunar Prospector gamma ray spectrometer, In general, the detailed features of the Procellarum/Imbrium KREEP terrane are found in both. For example, distinct highs in Gd, Sm, and Th abundances are resolved over the craters Mairan, Aristarchus, Kepler, Reinhold, Lalande, and Aristillus, over the Apennine Bench and Fra Mauro regions, and over the Montes Jura and Montes Carpatus, indicating an enhanced abundance of KREEP in these locations. The neutron observations also provide constraints on FeO and TiO2 abundances; for some high-Ti locales, there is a significant disagreement with TiO2 abundances inferred from Clementine spectral reflectance. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Hawaii, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. Univ Arizona, Lunar Res Inst, Tucson, AZ 85747 USA. RP Elphic, RC (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop D-466, Los Alamos, NM 87545 USA. RI Lawrence, David/E-7463-2015 OI Lawrence, David/0000-0002-7696-6667 NR 27 TC 88 Z9 88 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD AUG 25 PY 2000 VL 105 IS E8 BP 20333 EP 20345 DI 10.1029/1999JE001176 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348TY UT WOS:000089003600012 ER PT J AU Feldman, WC Lawrence, DJ Elphic, RC Vaniman, DT Thomsen, DR Barraclough, BL Maurice, S Binder, AB AF Feldman, WC Lawrence, DJ Elphic, RC Vaniman, DT Thomsen, DR Barraclough, BL Maurice, S Binder, AB TI Chemical information content of lunar thermal and epithermal neutrons SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GAMMA-RAY; PROSPECTOR; ABUNDANCES; CLEMENTINE; METEORITES; SPECTRA; FLUXES; CRUST; MOON AB Simulations of equilibrium thermal and epithermal neutron flux spectra for the Moon have been studied to determine their chemical information content, Most of this information resides in a single parameter, the ratio of macroscopic absorption to energy-loss cross sections. Although this parameter cannot specify the chemistry of lunar soils uniquely, it provides an index that can be used to quantitatively separate anorthositic from mafic chemistries. Hydrogen abundances can best be derived from measurements of the epithermal neutron flux, which is strongly related to its macroscopic energy-loss cross section. The ratio of thermal to epithermal neutron flux measured by Lunar Prospector is shown to agree quantitatively with simulations, This agreement is used to show that the highlands terrane on the farside of the Moon is anorthositic, containing high percentages of plagioclase and possibly a range of Mg-suite minerals with a high Mg/(Mg + Fe) atomic ratio. Our best estimate of the abundance of FeO is 2%, with an upper limit of 5%. C1 Univ Calif Los Alamos Natl Lab, Grp NIS1, Los Alamos, NM 87545 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. Lunar Res Inst, Tucson, AZ 85747 USA. RP Feldman, WC (reprint author), Univ Calif Los Alamos Natl Lab, Grp NIS1, POB 1663,MS D-466, Los Alamos, NM 87545 USA. RI Lawrence, David/E-7463-2015 OI Lawrence, David/0000-0002-7696-6667 NR 37 TC 55 Z9 60 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD AUG 25 PY 2000 VL 105 IS E8 BP 20347 EP 20363 DI 10.1029/1999JE001183 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348TY UT WOS:000089003600013 ER PT J AU Maurice, S Feldman, WC Lawrence, DJ Elphic, RC Gasnault, O d'Uston, C Genetay, I Lucey, PG AF Maurice, S Feldman, WC Lawrence, DJ Elphic, RC Gasnault, O d'Uston, C Genetay, I Lucey, PG TI High-energy neutrons from the Moon SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID PROSPECTOR GAMMA-RAY; LUNAR PROSPECTOR AB We present the first report dedicated to 0.6-8 MeV neutrons measured by the Lunar Prospector gamma-ray spectrometer. The period of data collection extends from January 1998 to July 1999; the spacecraft altitude varied between 15 km and 140 km. Maps are at a 2 degrees x2 degrees equal-area resolution, They show high counts and high variability for the mare and, low counts and low variability for the highlands. Such variability is due to differences of Fe and Ti concentrations in the lunar regolith, plus other elements with lesser effect that have not yet been included in our calculations. Assuming that only FeO and TiO2 concentrations are responsible for the fast neutron structures, fluxes are 2.7 times more sensitive to FeO than to TiO2, The statistical resolutions are 1.3% in FeO and 3.5% in TiO2. No discrimination of FeO is possible below 6.5%. Results are supported by numerical simulations, We also present the first lunar neutron spectrum over 16 channels between 0.6 and 8 MeV. Ninety-five percent of the counts are below similar to 4.5 MeV. In flux units the spectrum peaks at similar to 1.5 MeV, Its shape agrees with numerical simulations. C1 Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Hawaii, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. Ctr Etud Spatiale Rayonnements, Toulouse, France. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Maurice, S (reprint author), Observ Midi Pyrenees, 14 Ave Edouard Belin, F-31400 Toulouse, France. RI Gasnault, Olivier/F-4327-2010; Lawrence, David/E-7463-2015 OI Gasnault, Olivier/0000-0002-6979-9012; Lawrence, David/0000-0002-7696-6667 NR 13 TC 37 Z9 40 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-PLANET JI J. Geophys. Res.-Planets PD AUG 25 PY 2000 VL 105 IS E8 BP 20365 EP 20375 DI 10.1029/1999JE001151 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348TY UT WOS:000089003600014 ER PT J AU Bard, J Zhelkovsky, AM Helmling, S Earnest, TN Moore, CL Bohm, A AF Bard, J Zhelkovsky, AM Helmling, S Earnest, TN Moore, CL Bohm, A TI Structure of yeast poly(A) polymerase alone and in complex with 3 '-dATP SO SCIENCE LA English DT Article ID DNA-POLYMERASE; CRYSTAL-STRUCTURES; MESSENGER-RNA; BINDING; MECHANISM; DOMAIN; BETA; NUCLEOTIDYLTRANSFERASE; EUKARYOTES; FRAGMENT AB Polyadenylate [poly(A)] polymerase (PAP) catalyzes the addition of a polyadenosine tail to almost all eukaryotic messenger RNAs (mRNAs). The crystal structure of the PAP from Saccharomyces cerevisiae (Pap1) has been solved to 2.6 angstroms, both alone and in complex with 3'-deoxyadenosine triphosphate (3'-dATP). Like other nucleic acid polymerases, Pap1 is composed of three domains that encircle the active site. The arrangement of these domains, however, is quite different from that seen in polymerases that use a template to select and position their incoming nucleotides. The first two domains are functionally analogous to polymerase palm and fingers domains. The third domain is attached to the fingers domain and is' known to interact with the single-stranded RNA primer. In the nucleotide complex, two molecules of 3'-dATP are bound to Pap1, One occupies the position of the incoming base, prior to its addition to the mRNA chain. The other is believed to occupy the position of the 3' end of the mRNA primer. C1 Boston Biomed Res Inst, Watertown, MA 02472 USA. Tufts Univ, Sch Med, Dept Mol Microbiol, Boston, MA 02111 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys Sci, Macromol Crystallog Facil Adv Light Source, Berkeley, CA 94720 USA. Tufts Univ, Sch Med, Dept Biochem, Boston, MA 02111 USA. RP Bohm, A (reprint author), Boston Biomed Res Inst, 64 Grove St, Watertown, MA 02472 USA. FU NIGMS NIH HHS [R01 GM57218-01A2] NR 32 TC 84 Z9 86 U1 1 U2 1 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 25 PY 2000 VL 289 IS 5483 BP 1346 EP 1349 DI 10.1126/science.289.5483.1346 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 347RF UT WOS:000088942400037 PM 10958780 ER PT J AU Ulagappan, N Frei, H AF Ulagappan, N Frei, H TI Mechanistic study of CO2 photoreduction in Ti silicalite molecular sieve by FT-IR spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID NORMAL COORDINATE ANALYSIS; TITANIUM-OXIDE CATALYSTS; PHOTOCATALYTIC REDUCTION; VIBRATIONAL-SPECTRUM; CARBON-DIOXIDE; SOLID ARGON; H2O; ZEOLITES; TI-MCM-41; CH2OH AB The initial products of the photoreduction of gaseous CO2 in Ti silicalite molecular sieve using methanol as electron donor have been monitored by in-situ FT-IR spectroscopy. Reaction was induced by 266 nm excitation of the Ti+IV-O-II-->Ti+III-O-I ligand-to-metal charge-transfer transition of the framework center. HCO2H, CO, and HCO2CH3 were the observed products. CO escaped instantaneously into the gas phase and was recorded at high spectral resolution. The origin of the products was elucidated by infrared analysis of experiments with (CO2)-O-18, (CO2)-C-13, and (CH3OH)-C-13. The results show that CO originates from secondary photolysis of HCO2H, while HCO2CH3 emerges mainly from spontaneous Tishchenko reaction of CH2=O, the initial oxidation product of methanol. The key finding is that formic acid is the primary 2-electron reduction product of CO2 at the LMCT-excited Ti centers. This implies that C-H bond formation occurs in the initial steps of CO2 activation at the gas-micropore interface. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Mailstop Calvin Lab, Berkeley, CA 94720 USA. RP Frei, H (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Mailstop Calvin Lab, Berkeley, CA 94720 USA. NR 40 TC 71 Z9 73 U1 2 U2 53 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 24 PY 2000 VL 104 IS 33 BP 7834 EP 7839 DI 10.1021/jp001470i PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 347UQ UT WOS:000088947900014 ER PT J AU Wang, JX Robinson, IK DeVilbiss, JE Adzic, RR AF Wang, JX Robinson, IK DeVilbiss, JE Adzic, RR TI Structural trends among ionic mental-halide adlayers on electrode surfaces SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID X-RAY-SCATTERING; SCANNING-TUNNELING-MICROSCOPY; CU UNDERPOTENTIAL DEPOSITION; SINGLE-CRYSTAL ELECTRODES; IN-SITU STM; AU(111) ELECTRODE; ATOMIC-STRUCTURE; TL-ADLAYERS; COPPER; PT(111) AB X-ray diffraction techniques have been used to determine the structures of Tl-CI, Tl-I, and Pb-Br compounds adsorbed on Au(111) in acid solution. As in the previous case of Tl-Br, several well-defined mixed adlayer phases with stoichiometries of 1:1, 1:2, and 1:3 have been found over a wide potential region. Sufficient data have been gathered to explore the general structural trends among electrochemically prepared two-dimensional (2D) binary ionic compounds. The observed structural phase behavior is rationalized by symmetry and electrostatic considerations in 2D binary ionic crystals. For the 1:1 stoichiometry, square symmetry is generally preferred because it allows an ion to surround itself with the maximum number of counterions. On a hexagonal substrate, this becomes distorted to either a rectangle or a rhombus in commensurate or uniaxially commensurate phases, depending on whether the cation and anion layers are in the same plane. C1 Brookhaven Natl Lab, Div Mat & Chem Sci, Dept Appl Sci, Upton, NY 11973 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Wang, JX (reprint author), Brookhaven Natl Lab, Div Mat & Chem Sci, Dept Appl Sci, Bldg 555, Upton, NY 11973 USA. RI Wang, Jia/B-6346-2011 NR 44 TC 11 Z9 11 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD AUG 24 PY 2000 VL 104 IS 33 BP 7951 EP 7959 DI 10.1021/jp000759x PG 9 WC Chemistry, Physical SC Chemistry GA 347TR UT WOS:000088945700013 ER PT J AU Wick, CD Martin, MG Siepmann, JI AF Wick, CD Martin, MG Siepmann, JI TI Transferable potentials for phase equilibria. 4. United-atom description of linear and branched alkenes and alkylbenzenes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MONTE-CARLO SIMULATION; MOLECULAR SIMULATION; CHAIN MOLECULES; GIBBS ENSEMBLE; FORCE-FIELD; ALKANES; MIXTURES; SCHEME; EQUATION; BEHAVIOR AB The Transferable Potentials for Phase Equilibria-United Atom (TraPPE-UA) force field for hydrocarbons is extended to alkenes and alkylbenzenes by introducing the following pseudo-atoms: CH2(sp(2)), CH(sp(2)), C(sp(2)), CH(aro), R-C(aro) for the link to aliphatic side chains and C(aro) for the link of two benzene rings. In this united-atom force field, the nonbonded interactions of the hydrocarbon pseudo-atoms are solely governed by Lennard-Jones 12-6 potentials, and the Lennard-Jones well depth and size parameters for the new pseudoatoms were determined by fitting to the single-component vapor-liquid-phase equilibria of a few selected model compounds. Configurational-bias Monte Carlo simulations in the NVT version of the Gibbs ensemble were carried out to calculate the single-component vapor-liquid coexistence curves for ethene, propene, I-butene, trans- and cis-2-butene, 2-methylpropene, 1,5-hexadiene, 1-octene, benzene, toluene, ethylbenzene, propylbenzene, isopropylbenzene, o-, m-, and p-xylene, and naphthalene. The phase diagrams for the binary mixtures of (supercritical) ethene/n-heptane and benzene/n-pentane were determined from simulations in the NPT Gibbs ensemble. Although the TraPPE-UA force field is rather simple and makes use of relatively few different pseudo-atoms, its performance, as judged by comparisons to other popular force fields and available experimental data, is very satisfactory. C1 Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. Univ Minnesota, Dept Chem Engn, Minneapolis, MN 55455 USA. Univ Minnesota, Dept Mat Sci, Minneapolis, MN 55455 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Siepmann, JI (reprint author), Univ Minnesota, Dept Chem, 207 Pleasant St SE, Minneapolis, MN 55455 USA. NR 48 TC 280 Z9 284 U1 6 U2 93 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 24 PY 2000 VL 104 IS 33 BP 8008 EP 8016 DI 10.1021/jp001004x PG 9 WC Chemistry, Physical SC Chemistry GA 347TR UT WOS:000088945700021 ER PT J AU Johnston, CT Bish, DL Eckert, J Brown, LA AF Johnston, CT Bish, DL Eckert, J Brown, LA TI Infrared and inelastic neutron scattering study of the 1.03-and 0.95-nm kaolinite-hydrazine intercalation complexes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID HYDRATED KAOLINITES; LI-MONTMORILLONITES; DYNAMIC STRUCTURE; WATER; COMPOUND; MOLECULES; BEHAVIOR; SPECTRA; CLAY AB The interaction of hydrazine with kaolinite was studied using a combination of infrared (IR) spectroscopy, inelastic neutron scattering (INS), and X-ray powder diffraction. Under ambient temperature and pressure conditions, anhydrous hydrazine is readily intercalated into the interlamellar region of kaolinite resulting in a kaolinite-hydrazine (KH) intercalation complex with a 001 d-spacing of 1.03 nm. Under reduced pressure, the surface loading of hydrazine is reduced to 0.5 hydrazine molecules/unit cell, and the 001 rt-spacing of the KH complex undergoes a partial collapse to a highly ordered KH complex with a 001 d-spacing of 0.95 nm. This transition from 1.03 to 0.95 nm is accompanied by strong perturbations in the LR and INS, spectra for vibrational modes of bath the kaolinite and the intercalated hydrazine species. The transition from the 1.03 complex to the 0.95-nm KH complex is made possible by the keying of one of the hydrazine amine groups into the siloxane ditrigonal cavity of the kaolinite surface as evidenced by changes of the IR active stretching and bending modes of the inner OH group. The IR and INS spectra reveal strong hydrogen bonds between the intercalated hydrazine molecules and the kaolinite surface itself. The strongest hydrogen bonds are intermolecular hydrogen bonds formed between intercalated hydrazine molecules for the 1.03-nm KH complex and are manifested by a strong, broad band at 2975 cm(-1) in the IR spectrum. This band is absent in the IR spectrum of the 0.95 nm KH complex and is replaced by a band at 3270 cm(-1), indicating a net increase in the distance between Intercalated hydrazine molecules. Additionally, strong intercalation-induced perturbations occurred for the twist, scissor, asymmetric and symmetric wag modes, and torsional modes of hydrazine for both the 1.03- and 0.95-nm KH complexes. C1 Purdue Univ, W Lafayette, IN 47907 USA. Univ Calif Los Alamos Natl Lab, LANSCE, Los Alamos, NM 87545 USA. Arizona State Univ, Dept Chem, Tempe, AZ 85287 USA. RP Johnston, CT (reprint author), Purdue Univ, 1150 Lilly Hall, W Lafayette, IN 47907 USA. RI Johnston, Cliff/B-2215-2009 OI Johnston, Cliff/0000-0002-8462-9724 NR 54 TC 27 Z9 28 U1 1 U2 5 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 24 PY 2000 VL 104 IS 33 BP 8080 EP 8088 DI 10.1021/jp001075s PG 9 WC Chemistry, Physical SC Chemistry GA 347TR UT WOS:000088945700030 ER PT J AU de la Rubia, TD Zbib, HM Khraishi, TA Wirth, BD Victoria, M Caturla, MJ AF de la Rubia, TD Zbib, HM Khraishi, TA Wirth, BD Victoria, M Caturla, MJ TI Multiscale modelling of plastic flow localization in irradiated materials SO NATURE LA English DT Article ID ENERGY DISPLACEMENT CASCADES; MOLECULAR-DYNAMICS; COMPUTER-SIMULATION; INTERSTITIAL LOOPS; DEFECT PRODUCTION; SINGLE-CRYSTALS; METALS; DAMAGE; MICROSTRUCTURE; DISLOCATIONS AB The irradiation of metals by energetic particles causes significant degradation of the mechanical properties(1,2), most notably an increased yield stress and decreased ductility, often accompanied by plastic flow localization. Such effects limit the lifetime of pressure vessels in nuclear power plants(3), and constrain the choice of materials for fusion-based alternative energy sources(4). Although these phenomena have been known for many years(1), the underlying fundamental mechanisms and their relation to the irradiation field have not been clearly demonstrated. Here we use three-dimensional multiscale simulations of irradiated metals to reveal the mechanisms underlying plastic flow localization in defect-free channels. We observe dislocation pinning by irradiation-induced clusters of defects, subsequent unpinning as defects are absorbed by the dislocations, and cross-slip of the latter as the stress is increased. The width of the plastic flow channels is limited by the interaction among opposing dislocation dipole segments and the remaining defect clusters. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. EPFL, CRPP, CH-5232 Villigen, Switzerland. RP de la Rubia, TD (reprint author), Lawrence Livermore Natl Lab, 7000 E Ave,L-353, Livermore, CA 94550 USA. EM delarubia@llnl.gov RI Caturla, Maria /D-6241-2012; Wirth, Brian/O-4878-2015 OI Caturla, Maria /0000-0002-4809-6553; Wirth, Brian/0000-0002-0395-0285 NR 29 TC 160 Z9 160 U1 6 U2 68 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 24 PY 2000 VL 406 IS 6798 BP 871 EP 874 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 347AG UT WOS:000088903600038 ER PT J AU Barrett, C Jacob, R Marathe, M AF Barrett, C Jacob, R Marathe, M TI Formal-language-constrained path problems SO SIAM JOURNAL ON COMPUTING LA English DT Article DE algorithms; formal languages; computational complexity; transportation planning; World Wide Web; shortest paths; query processing; multicriteria problems ID SHORTEST-PATH; DECOMPOSABLE GRAPHS AB Given an alphabet Sigma, a (directed) graph G whose edges are weighted and Sigma-labeled, and a formal language L subset of or equal to Sigma*, the formal-language-constrained shortest/simple path problem consists of finding a shortest (simple) path p in G complying with the additional constraint that l(p) is an element of L. Here l(p) denotes the unique word obtained by concatenating the Sigma-labels of the edges along the path p. The main contributions of this paper include the following: (1) We show that the formal-language-constrained shortest path problem is solvable efficiently in polynomial time when L is restricted to be a context-free language (CFL). When L is specified as a regular language we provide algorithms with improved space and time bounds. (2) In contrast, we show that the problem of finding a simple path between a source and a given destination is NP-hard, even when L is restricted to fixed simple regular languages and to very simple classes of graphs (e.g., complete grids). (3) For the class of treewidth-bounded graphs, we show that (i) the problem of finding a regular-language-constrained simple path between source and destination is solvable in polynomial time and (ii) the extension to finding CFL-constrained simple paths is NP-complete. Our results extend the previous results in [SIAM J. Comput., 24 (1995), pp. 1235-1258; Proceedings of the 76th Annual Meeting of the Transportation Research Board, 1997; and Proceedings of the 9th ACM SIGACT-SIGMOD-SIGART Symposium on Database Systems, 1990, pp. 230-242]. Several additional extensions and applications of our results in the context of transportation problems are presented. For instance, as a corollary of our results, we obtain a polynomial-time algorithm for the best k-similar path problem studied in [Proceedings of the 76th Annual Meeting of the Transportation Research Board, 1997]. The previous best algorithm was given by [Proceedings of the 76th Annual Meeting of the Transportation Research Board, 1997] and takes exponential time in the worst case. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Aarhus Univ, Dept Comp Sci, Ctr Danish Res Fdn, DK-8000 Aarhus C, Denmark. RP Barrett, C (reprint author), Los Alamos Natl Lab, POB 1663,MS M997, Los Alamos, NM 87545 USA. EM barrett@lanl.gov; rjacob@brics.dk; marathe@lanl.gov NR 41 TC 46 Z9 46 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0097-5397 EI 1095-7111 J9 SIAM J COMPUT JI SIAM J. Comput. PD AUG 24 PY 2000 VL 30 IS 3 BP 809 EP 837 DI 10.1137/S0097539798337716 PG 29 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA 348VZ UT WOS:000089008300004 ER PT J AU Burkoth, TS Benzinger, TLS Urban, V Morgan, DM Gregory, DM Thiyagarajan, P Botto, RE Meredith, SC Lynn, DG AF Burkoth, TS Benzinger, TLS Urban, V Morgan, DM Gregory, DM Thiyagarajan, P Botto, RE Meredith, SC Lynn, DG TI Structure of the beta-amyloid((10-35)) fibril SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID AMYLOID-BETA-PROTEIN; NUCLEAR-MAGNETIC-RESONANCE; SYNCHROTRON X-RAY; ALZHEIMERS-DISEASE; PLAQUE COMPETENCE; SHEET; PEPTIDE; CORE; FIBRILLOGENESIS; HELIX AB The primary component of the amyloid plaques in Alzheimer's disease (AD) is a highly ordered fibril composed of the 39-43 amino acid peptide, beta-amyloid (A beta). The presence of this fibril has been correlated with both the onset and severity of the disease. Using a combination of synthetic model peptides, solid-state NMR, electron microscopy, and small angle neutron scattering (SANS), methods that allowed fibrils to be studied directly both in solution and in the solid state, the three-dimensional structure of fibrils formed from A beta((10-35)) is assigned. The structure consists of six laminated beta-sheets propagating and twisting along the fibril axis. Each peptide strand is oriented perpendicular to the helical axis in a parallel P-sheet, with each like amino acid residue in register along the sheet. The six sheets are laminated, probably also in parallel arrays, to give a fibril with dimensions of about 60 x 80 Angstrom. Both the methodology developed and the structural insight gained here lay the foundation for strategies to characterize and design materials capable of amyloidlike self-assembly. C1 Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Univ Chicago, Dept Pathol, Chicago, IL 60637 USA. Argonne Natl Lab, Intense Pulse Neutron Source & Chem Div, Argonne, IL 60439 USA. RP Lynn, DG (reprint author), Emory Univ, Dept Chem, Emerson Hall, Atlanta, GA 30322 USA. RI Urban, Volker/N-5361-2015 OI Urban, Volker/0000-0002-7962-3408 NR 62 TC 187 Z9 188 U1 2 U2 31 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 AUG 23 PY 2000 VL 122 IS 33 BP 7883 EP 7889 DI 10.1021/ja000645z PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 350CE UT WOS:000089082500005 ER PT J AU Kornilova, AY Wishart, JF Xiao, WZ Lasey, RC Fedorova, A Shin, YK Ogawa, MY AF Kornilova, AY Wishart, JF Xiao, WZ Lasey, RC Fedorova, A Shin, YK Ogawa, MY TI Design and characterization of a synthetic electron-transfer protein SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CYTOCHROME-C PEROXIDASE; X-RAY STRUCTURE; LEUCINE-ZIPPER; COILED-COIL; CONFORMATIONAL-CHANGES; DISTANCE DEPENDENCE; CIRCULAR-DICHROISM; TRANSFER RATES; DRIVING-FORCE; PEPTIDE AB A 30-residue polypeptide [H21(30-mer)] with the sequence Ac-K(IEALEGK)(2)(IEALEHK)-(IEALEGK)G-NH2 was synthesized. The circular dichroism (CD) spectrum of the peptide shows minima at 208 and 222 nm and theta(222)/theta(208) = 1.06, which indicates the formation of a self-assembled coiled-coil when dissolved in aqueous solution. The concentration dependence of the CD data can be fit to an expression that describes a two-state monomer-dimer equilibrium for the apopeptide (K-d = 1.5 +/- 0.4 mu M and theta(max) = -23 800 +/- 130 deg cm(2) dmol(-1)), showing that it has a maximum helicity of 69%. A [MTSL-C21(30-mer)] dimer was also prepared in which MTSL is the thiol-specific nitroxide spin label 1-oxyl-2,2,5,5-tetramethyl-Delta(3)-pyrroline-3-methyl-methanethiosulfonate attached to C21 of the 30-mer. Fourier deconvolution analysis of the dipolar line broadening of the electron paramagnetic resonance (EPR) spectrum yields a measure of the interchain C alpha-C alpha distance of 13.5 +/- 0.9 Angstrom at position 21 of the coiled-coil, which is nearly identical to those distances observed for the isostructural family of bZip proteins. Two metallohomodimers, [Ru(trpy)(bpy)-H21 (30-mer)](2) and [Ru(NH3)(5)-H21(30-mer)](2), in which the ruthenium complexes were coordinated with the H21 site of the 30-mer, were prepared. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), chemical cross-linking studies, and analytical ultracentrifugation show that the peptides exist as a dimeric coiled-coil with a molecular weight of similar to 7.5 kDa. The electron transfer (ET) heterodimer, [Ru(trpy)(bpy)-H21(30-mer)]/[Ru(NH3)(5)-H21(30-mer)], was prepared, and molecular modeling shows that the two metal complexes are separated by a metal-to-metal distance of similar to 24 Angstrom across the noncovalent peptide interface. Pulse radiolysis was used to measure an ET rate constant of k(et) = 380 +/- 80 s(-1) for the intracomplex electron transfer (Delta G degrees = -1.11 eV) from the Ru-II(NH3)(5)-H21 donor to the Ru-III(trpy)(bpy)-H21 acceptor. The value for k(et) falls within the range reported for modified proteins over comparable distances and supersedes the one reported in an earlier communication. C1 Bowling Green State Univ, Dept Chem, Bowling Green, OH 43403 USA. Bowling Green State Univ, Ctr Photochem Sci, Bowling Green, OH 43403 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Struct Biol, Berkeley, CA 94720 USA. RP Ogawa, MY (reprint author), Bowling Green State Univ, Dept Chem, Bowling Green, OH 43403 USA. RI Wishart, James/L-6303-2013; OI Wishart, James/0000-0002-0488-7636; xiao, wenzhong/0000-0003-4944-6380 NR 66 TC 42 Z9 42 U1 3 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 23 PY 2000 VL 122 IS 33 BP 7999 EP 8006 DI 10.1021/ja0006954 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 350CE UT WOS:000089082500016 ER PT J AU Di Teodoro, F Rehm, JE Farrow, RL Paul, PH AF Di Teodoro, F Rehm, JE Farrow, RL Paul, PH TI Collisional quenching of CO B (1)Sigma(+)(v(')=0) probed by two-photon laser-induced fluorescence using a picosecond laser SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CARBON-MONOXIDE; HYDROCARBON FLAMES; STIMULATED-EMISSION; RADIATIVE LIFETIMES; COMBUSTION GASES; RYDBERG STATES; CROSS-SECTION; NITRIC-OXIDE; ABSORPTION; EXCITATION AB We report measurements of room-temperature, species-specific quenching cross sections of CO B (1)Sigma(+) (v' = 0) in collisions with He, Ne, H-2, N-2, Ar, CO, Kr, CH4, O-2, Xe, CO2, C3H8, and H2O. The measured quenching cross sections (in Angstrom(2)) were 0.25 +/- 0.02, 0.54 +/- 0.04, 11.0 +/- 0.4, 24.6 +/- 0.5, 27.7 +/- 0.5, 37 +/- 2, 42 +/- 2, 81 +/- 4, 85 +/- 5, 99 +/- 6, 133 +/- 5, 144 +/- 7, and 170 +/- 8, respectively. Two-photon excitation of the CO molecules via the Hopfield-Birge system (X (1)Sigma(+)-->--> B (1)Sigma(+)) was performed using the frequency-tripled 690 nm emission of a custom-built picosecond dye laser. Blue-to-green fluorescence in the Angstrom bands (B (1)Sigma(+)--> A (1)Pi) was detected using a microchannel-plate photomultiplier tube and recorded with a digital storage oscilloscope. The quenching cross sections were directly obtained by time resolving the temporal decay of the fluorescence signal and observing its variation as a function of the quencher pressure. The effect of radiative trapping on the observed fluorescence was also quantitatively modeled. (C) 2000 American Institute of Physics. [S0021-9606(00)02332-1]. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Di Teodoro, F (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 57 TC 13 Z9 13 U1 0 U2 10 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 AUG 22 PY 2000 VL 113 IS 8 BP 3046 EP 3054 DI 10.1063/1.1287144 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 345AG UT WOS:000088792800016 ER PT J AU Forde, NR Butler, LJ Ruscic, B Sorkhabi, O Qi, F Suits, A AF Forde, NR Butler, LJ Ruscic, B Sorkhabi, O Qi, F Suits, A TI Characterization of nitrogen-containing radical products from the photodissociation of trimethylamine using photoionization detection SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID BOND-DISSOCIATION ENERGIES; ADVANCED LIGHT-SOURCE; HIGH-FLUX BEAMLINE; PROTON AFFINITIES; CHEMICAL-DYNAMICS; HIGH-RESOLUTION; AB-INITIO; 193 NM; IONS; PERFORMANCE AB The outcome of neutral and photoionized N(CH3)(2) primary products of trimethylamine photodissociation at 193 nm is determined by combining photoionization detection with supporting G3 theoretical calculations. N(CH3)(2) primary products with very little internal energy show an experimentally observed ionization onset of 9.1 +/- 0.2 eV, but do not appear at the parent ion (m/e = 44). Instead, the parent ion is unstable and easily fragments to m/e = 42, where the signal is observed. N(CH3)(2) radicals with higher internal energies undergo H-atom loss from the neutral to give CH2NCH3, which has an observed ionization onset at parent (m/e = 43) of < 9.3 eV. At slightly higher ionization energies, these secondary products also appear at m/e = 42 (where their appearance energy is roughly 9.8-9.9 eV, uncorrected for internal energy). Finally, N(CH3)(2) radicals with the highest internal energy in this study appear to undergo H-2 loss as neutrals, giving rise to a species whose parent ion has m/e = 42. The ionization onset of this species at m/e = 42 is found to be in the range of 9.5-9.6 eV. (C) 2000 American Institute of Physics. [S0021-9606(00)01332-5]. C1 Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Forde, NR (reprint author), Univ Chicago, James Franck Inst, 5640 S Ellis Ave, Chicago, IL 60637 USA. RI Qi, Fei/A-3722-2012; Ruscic, Branko/A-8716-2008; Forde, Nancy/D-8865-2015 OI Ruscic, Branko/0000-0002-4372-6990; NR 42 TC 6 Z9 7 U1 0 U2 8 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 AUG 22 PY 2000 VL 113 IS 8 BP 3088 EP 3097 DI 10.1063/1.1286973 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 345AG UT WOS:000088792800020 ER PT J AU Wu, G Schatz, GC Lendvay, G Fang, DC Harding, LB AF Wu, G Schatz, GC Lendvay, G Fang, DC Harding, LB TI A new potential surface and quasiclassical trajectory study of H+H2O -> OH+H-2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ANGULAR-MOMENTUM ALIGNMENT; BOND-SPECIFIC CHEMISTRY; ENERGY SURFACES; REACTION DYNAMICS; BIMOLECULAR REACTION; OH PRODUCT; OH+H-2->H2O+H REACTION; STATE DISTRIBUTIONS; VIBRATIONAL-STATE; CROSS-SECTIONS AB We present a method for developing potential-energy surfaces for abstraction reactions with four or more atoms which combines spline fits to high quality ab initio results for the three degrees of freedom that are most active in the reaction (two stretches and a bend) with simple empirical functions (Morse stretches, cosine bends, and torsions) for the spectator variables. The geometry and force constants associated with the spectator modes are allowed to vary along the reaction path so as to match stationary point properties from the ab initio calculations. In an application of this approach to the H + H2O reaction, we are able to generate a global surface for the H3O system that accurately matches ab initio properties, and is globally smooth and free of artifacts. Quasiclassical trajectory (QCT) calculations are used with this surface to study the H + H2O reaction dynamics for both the ground and local mode excited states. The resulting ground-state angular distributions, product state vibrational and rotational distributions, and rotational alignment factors are in excellent agreement with all known experiments. This represents an improvement over the results obtained using previous surfaces, but like the past surfaces, the calculated integral cross sections are below experiment by at least a factor of 2. For studies of the H + H2O reaction involving local mode excited states of water, the new surface is consistent with ab initio threshold behavior, with the (04)(-) local mode state having zero activation energy. However the reactive rate coefficients are substantially smaller than the observed total reactive plus inelastic rate coefficient. This indicates that recent experiments due to Barnes, Sharkey, Sims, and Smith are dominated by energy transfer rather than reaction. (C) 2000 American Institute of Physics. [S0021-9606(00)03432-2]. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Hungarian Acad Sci, Inst Chem, Chem Res Ctr, H-1525 Budapest, Hungary. Argonne Natl Lab, Theoret Chem Grp, Argonne, IL 60439 USA. RP Northwestern Univ, Dept Chem, 2145 Sheridan Rd, Evanston, IL 60208 USA. EM schatz@chem.nwu.edu RI Lendvay, Gyorgy/B-5397-2016 OI Lendvay, Gyorgy/0000-0002-2150-0376 NR 51 TC 95 Z9 96 U1 2 U2 13 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 22 PY 2000 VL 113 IS 8 BP 3150 EP 3161 AR PII [S0021-9606(00)03432-2] DI 10.1063/1.1287329 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 345AG UT WOS:000088792800028 ER PT J AU Zapol, P Curtiss, LA Erdemir, A AF Zapol, P Curtiss, LA Erdemir, A TI Periodic ab initio calculations of orthoboric acid SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HARTREE-FOCK; BORIC-ACID; DENSITY; BEHAVIOR AB Periodic ab initio calculations for orthoboric acid were performed. Geometries of a monolayer and a three-dimensional molecular crystal were optimized. Intermolecular interactions within the layer are found to be about three times stronger than the interaction between layers. Layer buckling is shown to be caused by interlayer interactions. Deformation density maps are given and changes in the density distribution induced by intermolecular interactions are discussed. (C) 2000 American Institute of Physics. [S0021-9606(00)30627-4]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Zapol, P (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Zapol, Peter/G-1810-2012 OI Zapol, Peter/0000-0003-0570-9169 NR 18 TC 18 Z9 18 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 22 PY 2000 VL 113 IS 8 BP 3338 EP 3343 AR PII [S0021-9606(00)30627-4] DI 10.1063/1.1286220 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 345AG UT WOS:000088792800049 ER PT J AU Wu, JZ Bratko, D Blanch, HW Prausnitz, JM AF Wu, JZ Bratko, D Blanch, HW Prausnitz, JM TI Effect of three-body forces on the phase behavior of charged colloids SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MONTE-CARLO; SUSPENSIONS; ATTRACTION AB Statistical-thermodynamic theory for predicting the phase behavior of a colloidal solution requires the pair interaction potential between colloidal particles in solution. In practice, it is necessary to assume pairwise additivity for the potential of mean force between colloidal particles, but little is known concerning the validity of this assumption. This paper concerns interaction between small charged colloids, such as surfactant micelles or globular proteins, in electrolyte solutions and the multibody effect on phase behavior. Monte Carlo simulations for isolated colloidal triplets in equilateral configurations show that, while the three-body force is repulsive when the three particles are near contact, it becomes short-ranged attractive at further separations, contrary to a previous study where the triplet force is attractive at all separations. The three-body force arises mainly from hard-sphere collisions between colloids and small ions; it is most significant in solutions of monovalent salt at low concentration where charged colloids experience strong electrostatic interactions. To illustrate the effect of three-body forces on the phase behavior of charged colloids, we calculated the densities of coexisting phases using van der Waals-type theories for colloidal solutions and for crystals. For the conditions investigated in this work, even though the magnitude of the three-body force may be as large as 10% of the total force at small separations, three-body forces do not have a major effect on the densities of binary coexisting phases. However, coexisting densities calculated using Derjaguin-Landau-Verwey-Overbeek theory are much different from those calculated using our simulated potential of mean force. (C) 2000 American Institute of Physics. [S0021-9606(00)51232-X]. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Wu, JZ (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RI Wu, Jianzhong/I-5164-2013; OI Wu, Jianzhong/0000-0002-4582-5941 NR 24 TC 43 Z9 43 U1 0 U2 6 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 AUG 22 PY 2000 VL 113 IS 8 BP 3360 EP 3365 DI 10.1063/1.1287173 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 345AG UT WOS:000088792800052 ER PT J AU Bluhm, EA Schroeder, NC Bauer, E Fife, JN Chamberlin, RM Abney, KD Young, JS Jarvinen, GD AF Bluhm, EA Schroeder, NC Bauer, E Fife, JN Chamberlin, RM Abney, KD Young, JS Jarvinen, GD TI Surface effects on metal ion transport across porous alumina membranes. 2. Trivalent cations: Am, Tb, Eu, and Fe SO LANGMUIR LA English DT Article ID SPACE-CHARGE MODEL; NANOFILTRATION MEMBRANES; MICROPOROUS MEMBRANES; ELECTROLYTE TRANSPORT; CYLINDRICAL CAPILLARY; REJECTION; SELECTIVITY AB Transport behavior of trivalent solutes across mesoporous Anopore gamma-alumina membranes was investigated as a function of re diameter, pH, ionic strength, and nature of the salt in solution. Radiotracers, Fe-55, Eu-152, Tb-157, and Am-241, were present in the feed solutions at concentrations ranging from 10(-8) to 10(-10) M. Total salt concentrations in the feed ranged from 1.0 to 10(-4) M. Order of magnitude differences between experimental and theoretical diffusion rates for the membranes can be explained in terms of electrostatic interactions between the cations and the positively charged membrane surface. The rates of Am3+ and Tb3+ transport across the alumina membranes were greatly increased by raising the ionic strength from 10(-3) to 0.1 M in both the feed and permeate solutions; however, EU3+ diffusion rates were only slightly affected in this range of ionic strength. Trivalent cation transport rates at total salt concentrations greater than 0.1 M were slower than divalent cations due to enhanced electrostatic interactions between the alumina surface and the higher valent 3+ cations. Alkali metals present in both the feed and permeate solutions slightly influenced iron transport. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. RP Bluhm, EA (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, MS J514, Los Alamos, NM 87545 USA. RI Chamberlin, Rebecca/A-1335-2011 OI Chamberlin, Rebecca/0000-0001-6468-7778 NR 26 TC 29 Z9 29 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD AUG 22 PY 2000 VL 16 IS 17 BP 7056 EP 7060 DI 10.1021/la000357g PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 345KW UT WOS:000088816000046 ER PT J AU Garrett, JT Runt, J Lin, JS AF Garrett, JT Runt, J Lin, JS TI Microphase separation of segmented poly(urethane urea) block copolymers SO MACROMOLECULES LA English DT Article ID ANGLE X-RAY; POLYURETHANE ELASTOMERS; PHASE SEGREGATION; MICRODOMAIN STRUCTURE; LENGTH DISTRIBUTION; HARD SEGMENTS; SCATTERING; MDI; BEHAVIOR; POLYMERS AB Two series of well-defined poly(urethane urea) multiblock copolymers were synthesized to investigate the phase-separated morphology of this family of materials. Series I copolymers were synthesized from 2000 g/mol, poly(tetramethylene oxide) [PTMO], 4,4'-methylene di(p-phenyl isocyanate) [MDI], and ethylenediamine (EDA), with hard segment contents ranging from 14 to 47 wt %. Series II copolymers (all with hard segment concentrations of 22 wt %) were prepared from the same PTMO and MDI and a diamine mixture of EDA and 1,4-diaminocyclohexane. The microdomain morphology was characterized using small-angle X-ray scattering, and the scattering data were analyzed using the approach of Bonart and Muller. The series I and II copolymers were found to have relatively low overall degrees of phase separation [ranging from similar to 20% at the lowest hard segment contents to greater than 40%], contrary to the common nation that these copolymers are well phase separated materials. The introduction of the second diamine results in reduced phase separation; presumably as a consequence;of disruption of hard segment hydrogen bonding. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Runt, J (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RI He, Yong/F-8752-2012 NR 41 TC 139 Z9 140 U1 8 U2 69 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 22 PY 2000 VL 33 IS 17 BP 6353 EP 6359 DI 10.1021/ma000600i PG 7 WC Polymer Science SC Polymer Science GA 348AK UT WOS:000088961400024 ER PT J AU Trollsas, M Atthof, B Wursch, A Hedrick, JL Pople, JA Gast, AP AF Trollsas, M Atthof, B Wursch, A Hedrick, JL Pople, JA Gast, AP TI Constitutional isomers of dendrimer-like star polymers: Design, synthesis, and conformational and structural properties SO MACROMOLECULES LA English DT Article ID FREE-RADICAL POLYMERIZATION; ANGLE NEUTRON-SCATTERING; ALIPHATIC POLYESTERS; METHYL-METHACRYLATE; MOLECULAR-DYNAMICS; INTEGRAL-EQUATIONS; BLOCK-COPOLYMERS; MONTE-CARLO; MACROMOLECULES; POLYSTYRENE AB The design, synthesis, and solution properties of six constitutional isomers of dendrimer-like star polymers is described. Each of the polymers have comparable molecular weights (similar to 80 000), narrow polydispersities (<1.19) and an identical number of branching junctures (45) and surface hydroxyl functionalities (48). The only difference in the six isomers is the placement of the branching junctures. The polymers are constructed from high molecular weight poly(epsilon-caprolactohe) with branching junctures derived from 2,2'-bis(hydroxylmethyl) propionic acid (bis-MPA) emanating from a central core. The use of various generations of dendritic initiators and dendrons coupled with the ring-opening polymerization of epsilon-caprolactones allowed a modular approach to the dendrimer-like star polymer isomers. The most pronounced effects on the physical properties/morphology and hydrodynamic volume was for those polymers in which the branching was distributed throughout the sample in a dendrimer-like fashion. The versatility of this approach has provided the possibility of understanding the relationship between architecture and physical properties. Dynamic light scattering and small-angle X-ray scattering techniques were used to determine the hydrodynamic radius R-h and radius of gyration R-g respectively. The relationship between R-g and molecular weight was indicative of a compact starlike structure, and did not show advanced bias toward either the dense core or dense shell models. The radial density distribution of the isomers was therefore modeled according to a many arm star polymer, and good agreement was found with experimental measures of R-h/R-g. C1 Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. RP Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA. NR 77 TC 80 Z9 80 U1 0 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD AUG 22 PY 2000 VL 33 IS 17 BP 6423 EP 6438 DI 10.1021/ma000321v PG 16 WC Polymer Science SC Polymer Science GA 348AK UT WOS:000088961400034 ER PT J AU Cohen, Y Albalak, RJ Dair, BJ Capel, MS Thomas, EL AF Cohen, Y Albalak, RJ Dair, BJ Capel, MS Thomas, EL TI Deformation of oriented lamellar block copolymer films SO MACROMOLECULES LA English DT Article ID GRAIN-BOUNDARY MORPHOLOGY; TRIBLOCK COPOLYMER; MECHANICAL-PROPERTIES; THERMOPLASTIC ELASTOMERS; DIBLOCK COPOLYMERS; ORIENTATION; BEHAVIOR; PHASE; INSTABILITIES; CRYSTALS AB Highly ordered, near-single-crystal lamellar films of a triblock copolymer (polystyrene-polybutadiene-polystyrene, PS/PB/PS) were used to study the deformation mechanism of a structure of alternating glassy-rubbery layers, at different orientations of the deformation axis relative to the layer normal. Synchrotron radiation was used for simultaneous in-situ deformation and small-angle X-ray scattering measurements. These were augmented with direct imaging of the structure by transmission electron microscopy. The deformation mechanism depends on the orientation of the force with respect to the structure. Loading parallel to the lamellae results in yielding by propagation of a stable macroscopic neck. The glassy PS layers break up at the neck front, releasing the rubbery layers to achieve high strain. The morphology that develops by deformation of the structure in other directions is an ensemble of new tilt boundaries oriented along the deformation axis. The lamellar normals tilt away from the deformation axis with increasing strain, keeping the lamellar spacing essentially constant. The effect of force applied perpendicular to the lamellae is to fold the layers into a "chevron" morphology, similar to other layered systems such as smectic liquid crystals. At high strain, plastic deformation and fracture of the glassy PS hinges of the "chevron" structure leads to symmetric kink boundaries parallel to the force axis. In addition, nucleation of kink band's around defects and propagation of the kink boundaries into adjacent regions can lead to a similar morphology. The lamellar spacing remains constant during perpendicular stretching, and the tilt angle of the lamellar normal follows the macroscopic deformation in an affine manner. Stretching at 45 degrees forms asymmetric kink boundaries parallel to the force axis. The major limbs of the kink band tilt with increasing strain so that the angle between the lamellar normal and the force axis increases from its initial value of 45 degrees, while the lamellar period remains constant. The minor limbs tilt in the opposite direction and exhibit dilation of the lamellar spacing. Eventually the layers rupture, forming voids at the kink-boundary interfaces. The tilt angle of the major-limb lamellae, as a function of strain, is less than predicted by the affine model. This study suggests a general deformation mechanism for a lamellar structure of alternating glassy and rubbery layers. The layered structure responds to deformation, in any direction other then parallel;to the layers, by creating new internal tilt-grain boundaries parallel to the deformation axis. At higher strain the layers yield and subsequently fracture at the kink-boundary interfaces. With increasing strain the lamellar stacks between the kink boundaries tilt toward the deformation axis until they are nearly parallel to it. Since the main features of this mechanism are independent of the initial orientation angle of the layers relative to the deformation axis, it is relevant also to polygranular, globally unoriented lamellar structures. C1 MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Thomas, EL (reprint author), MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. NR 51 TC 118 Z9 119 U1 5 U2 34 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 22 PY 2000 VL 33 IS 17 BP 6502 EP 6516 DI 10.1021/ma000513q PG 15 WC Polymer Science SC Polymer Science GA 348AK UT WOS:000088961400042 ER PT J AU Rockett, A Britt, JS Gillespie, T Marshall, C Al Jassim, MM Hasoon, F Matson, R Basol, B AF Rockett, A Britt, JS Gillespie, T Marshall, C Al Jassim, MM Hasoon, F Matson, R Basol, B TI Na in selenized Cu(In,Ga)Se-2 on Na-containing and Na-free glasses: distribution, grain structure, and device performances SO THIN SOLID FILMS LA English DT Article DE CuInSe2; photovoltaics; thin films; sodium; chalcogens; selenides ID CUINSE2; SODIUM AB We examined the effect of deposition of Na on Mo-coated glasses and the Na content of the substrate glass on standard production Cu(In1-xGax)Se-2 (CIGS)-based solar cells fabricated by selenization of Cu-Ga-In precursor thin films. Under optimal conditions, net Na content has a larger effect on the films than does the choice of substrate glass. Device performances improved with modest amounts of added Na on borosilicate glass. Device performances on soda-lime glass were not improved by adding Na. The supply of Na appears to have been adequate from the glass itself. A peak in device performance was found as a function of integrated Na in the CIGS layer as determined by secondary ion mass spectrometry (SIMS). The Na is found primarily in the areas of decreased grain size in the selenized CIGS where Ga is also found. S, deposited with the Na does not end up in the same place as does the Na. Rather, it tends to move toward the surface and accumulate in a buried layer. This is probably due to the reaction process rather than to the microstructure. Oxygen has no apparent effect on Na behavior in the CIGS. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Univ Illinois, Urbana, IL 61801 USA. Energy Photovolta Inc, Princeton, NJ 08543 USA. Lockheed Martin Astronaut, Denver, CO 80201 USA. Natl Renewable Energy Lab, Golden, CO USA. ISET Inc, Inglewood, CA 90301 USA. RP Rockett, A (reprint author), Univ Illinois, 1-107 ESB,1101 W Springfield Ave, Urbana, IL 61801 USA. RI Rockett, Angus/A-3218-2008; Rockett, Angus/B-5539-2013 OI Rockett, Angus/0000-0001-9759-8421 NR 14 TC 60 Z9 60 U1 2 U2 41 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 AUG 22 PY 2000 VL 372 IS 1-2 BP 212 EP 217 DI 10.1016/S0040-6090(00)01028-2 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 353HY UT WOS:000089269800029 ER PT J AU Chatterjee, A Kalia, RK Nakano, A Omeltchenko, A Tsuruta, K Vashishta, P Loong, CK Winterer, M Klein, S AF Chatterjee, A Kalia, RK Nakano, A Omeltchenko, A Tsuruta, K Vashishta, P Loong, CK Winterer, M Klein, S TI Sintering, structure, and mechanical properties of nanophase SiC: A molecular-dynamics and neutron scattering study SO APPLIED PHYSICS LETTERS LA English DT Article ID POWDERS AB Structure, mechanical properties, and sintering of nanostructured SiC (n-SiC) are investigated with neutron scattering and molecular-dynamics (MD) techniques. Both MD and the experiment indicate the onset of sintering around 1500 K. During sintering, the pores shrink while maintaining their morphology: the fractal dimension is similar to 2 and the surface roughness exponent is similar to 0.45. Structural analyses reveal that interfacial regions in n-SiC are disordered with nearly the same number of three- and fourfold coordinated Si atoms. The elastic moduli scale with the density as similar to rho(mu), where mu=3.4 +/- 0.1. (C) 2000 American Institute of Physics. [S0003-6951(00)04334-5]. C1 Louisiana State Univ, Dept Phys & Astron, Concurrent Comp Lab Mat Simulat, Baton Rouge, LA 70803 USA. Louisiana State Univ, Dept Comp Sci, Baton Rouge, LA 70803 USA. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Tech Univ Darmstadt, Dept Mat Sci, D-64287 Darmstadt, Germany. RP Chatterjee, A (reprint author), Louisiana State Univ, Dept Phys & Astron, Concurrent Comp Lab Mat Simulat, Baton Rouge, LA 70803 USA. RI Tsuruta, Kenji/B-2131-2011; Winterer, Markus/N-2069-2015 OI Tsuruta, Kenji/0000-0002-1447-2530; NR 17 TC 33 Z9 33 U1 0 U2 5 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 AUG 21 PY 2000 VL 77 IS 8 BP 1132 EP 1134 DI 10.1063/1.1289661 PG 3 WC Physics, Applied SC Physics GA 344ZU UT WOS:000088791600022 ER PT J AU Soyez, G Eastman, JA Thompson, LJ Bai, GR Baldo, PM McCormick, AW DiMelfi, RJ Elmustafa, AA Tambwe, MF Stone, DS AF Soyez, G Eastman, JA Thompson, LJ Bai, GR Baldo, PM McCormick, AW DiMelfi, RJ Elmustafa, AA Tambwe, MF Stone, DS TI Grain-size-dependent thermal conductivity of nanocrystalline yttria-stabilized zirconia films grown by metal-organic chemical vapor deposition SO APPLIED PHYSICS LETTERS LA English DT Article ID BARRIER COATINGS; NANOINDENTATION; CERAMICS; TIO2 AB A grain-size-dependent reduction in the room-temperature thermal conductivity of nanocrystalline yttria-stabilized zirconia is reported for the first time. Films were grown by metal-organic chemical vapor deposition with controlled grain sizes from 10 to 100 nm. For grain sizes smaller than approximately 30 nm, a substantial reduction in thermal conductivity was observed, reaching a value of less than one-third the bulk value at the smallest grain sizes measured. The observed behavior is consistent with expectations based on an estimation of the phonon mean-free path in zirconia. (C) 2000 American Institute of Physics. [S0003-6951(00)05034-8]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Reactor Engn Div, Argonne, IL 60439 USA. Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA. RP Eastman, JA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Eastman, Jeffrey/E-4380-2011; Stone, Donald/A-7496-2016; OI Eastman, Jeff/0000-0002-0847-4265 NR 19 TC 109 Z9 110 U1 2 U2 21 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 AUG 21 PY 2000 VL 77 IS 8 BP 1155 EP 1157 DI 10.1063/1.1289803 PG 3 WC Physics, Applied SC Physics GA 344ZU UT WOS:000088791600030 ER PT J AU Gim, Y Hudson, T Fan, Y Kwon, C Findikoglu, AT Gibbons, BJ Park, BH Jia, QX AF Gim, Y Hudson, T Fan, Y Kwon, C Findikoglu, AT Gibbons, BJ Park, BH Jia, QX TI Microstructure and dielectric properties of Ba1-xSrxTiO3 films grown on LaAlO3 substrates SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILMS; DEVICES AB We report a systematic study of the microstructure and dielectric properties of barium strontium titanate, Ba1-xSrxTiO3, films grown by laser ablation on LaAlO3 substrates, where x=0.1-0.9 at an interval of 0.1. X-ray diffraction analysis shows that when x < 0.4, the longest unit-cell axis is parallel to the plane of the substrate but perpendicular as x approaches 1. Dielectric constant versus temperature measurements show that the relative dielectric constant has a maximum value and that the peak temperatures corresponding to the maximum relative dielectric constant are about 70 degrees C higher when x less than or equal to 0.4 but similar when x > 0.4, compared with the peak temperatures of the bulk Ba1-xSrxTiO3. At room temperature, the dielectric constant and tunability are relatively high when x less than or equal to 0.4 but start to decrease rapidly as x increases. (C) 2000 American Institute of Physics. [S0003-6951(00)01534-5]. C1 Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Jia, QX (reprint author), Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Mail Stop K763, Los Alamos, NM 87545 USA. RI Park, Bae Ho/D-4840-2011; Jia, Q. X./C-5194-2008 NR 13 TC 137 Z9 148 U1 4 U2 15 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 AUG 21 PY 2000 VL 77 IS 8 BP 1200 EP 1202 AR PII [S0003-6951(00)01534-5] DI 10.1063/1.1289272 PG 3 WC Physics, Applied SC Physics GA 344ZU UT WOS:000088791600045 ER PT J AU Dahlbacka, G AF Dahlbacka, G TI A DOE program is turning swords into plowshares SO ELECTRONIC DESIGN LA English DT Editorial Material C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Dahlbacka, G (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PENTON MEDIA, INC PI CLEVELAND PA 1100 SUPERIOR AVE, CLEVELAND, OH 44114-2543 USA SN 0013-4872 J9 ELECTRON DES JI Electron. Des. PD AUG 21 PY 2000 VL 48 IS 17 BP 52 EP 52 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA 347ZT UT WOS:000088959700010 ER PT J AU Bond, DL Clark, DL Donohoe, RJ Gordon, JC Gordon, PL Keogh, DW Scott, BL Tait, CD Watkin, JG AF Bond, DL Clark, DL Donohoe, RJ Gordon, JC Gordon, PL Keogh, DW Scott, BL Tait, CD Watkin, JG TI A new structural class of lanthanide carbonates: Synthesis, properties, and X-ray structure of the one-dimensional ch sin complex [Co(NH3)(6)](6)[K-2(H2O)(10)]-[Nd-2(CO3)(8)](2)center dot 20H(2)O SO INORGANIC CHEMISTRY LA English DT Article ID RARE-EARTH CARBONATE; CRYSTAL-STRUCTURE; BURBANKITE; SOLUBILITY; NEPTUNIUM; DIFFUSION; EXAFS AB The neodymium tetracarbonate complex [Co(NH3)(6)](6)-[K-2(H2O)(10)][Nd-2(CO3)(8)](2). 20H(2)O (1) has bt:en prepared and characterized. A single-crystal X-ray diffraction study of 1 reveals a pseudo-one-dimensional infinite chain of nine-coordinate neodymium metal centers, each complexed by three bidentate carbonate ligands in a pseudoequatorial fashion, while a fourth bidentate carbonate group occupies an axial coordination site on each metal and acts as a mu(2)-eta(2),eta(1) bridge between adjacent chain units. C1 Univ Calif Los Alamos Natl Lab, NMT Div, Glenn T Seaborg Inst Transactinium Sci, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, CST Div 18, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Biosci Div 2, Los Alamos, NM 87545 USA. RP Gordon, PL (reprint author), Univ Calif Los Alamos Natl Lab, NMT Div, Glenn T Seaborg Inst Transactinium Sci, Mail Stop J514, Los Alamos, NM 87545 USA. RI Clark, David/A-9729-2011; Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 58 TC 15 Z9 15 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD AUG 21 PY 2000 VL 39 IS 17 BP 3934 EP + DI 10.1021/ic0001255 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 347ZL UT WOS:000088959100033 PM 11196793 ER PT J AU Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, AC Bennett, DP Charles, PA Cook, KH Drake, AJ Freeman, KC Geha, M Griest, K Groot, P Lehner, MJ Marshall, SL McGowan, KE Minniti, D Nelson, CA Peterson, BA Popowski, P Pratt, MR Quinn, PJ Sutherland, W Tomaney, AB Vandehei, T van Paradijs, J AF Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, AC Bennett, DP Charles, PA Cook, KH Drake, AJ Freeman, KC Geha, M Griest, K Groot, P Lehner, MJ Marshall, SL McGowan, KE Minniti, D Nelson, CA Peterson, BA Popowski, P Pratt, MR Quinn, PJ Sutherland, W Tomaney, AB Vandehei, T van Paradijs, J TI Searching for periodicities in the MACHO light curve of LMC X-2 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE binaries : close; stars : individual : LMC X-2; X-rays : stars ID X-RAY BINARIES; LARGE MAGELLANIC CLOUD; SPACED DATA; CYGNUS X-2; MASS; PHOTOMETRY; BULGE; HALO; STAR AB Using the exceptional long-term monitoring capabilities of the MACHO project, we present here the optical history of LMC X-2 for a continuous 6-yr period. These data were used to investigate the previously claimed periodicities for this source of 8.15 h and 12.54 d: we find upper limits of 0.10 mag and 0.09 mag, respectively. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Oxford, Dept Astrophys, Nucl Phys Lab, Oxford OX1 3RH, England. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 90064 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, CHEAF, NL-1098 SJ Amsterdam, Netherlands. Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England. Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. European So Observ, D-85748 Garching, Germany. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RP Alcock, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Quinn, Peter/B-3638-2013; Groot, Paul/K-4391-2016; OI Groot, Paul/0000-0002-4488-726X; Lehner, Matthew/0000-0003-4077-0985 NR 30 TC 3 Z9 3 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD AUG 21 PY 2000 VL 316 IS 4 BP 729 EP 733 DI 10.1046/j.1365-8711.2000.03511.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 350LP UT WOS:000089102700004 ER PT J AU Russell, LB Hunsicker, PR Kerley, MK Johnson, DK Shelby, MD AF Russell, LB Hunsicker, PR Kerley, MK Johnson, DK Shelby, MD TI Bleomycin, unlike other male-mouse mutagens, is most effective in spermatogonia, inducing primarily deletions SO MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS LA English DT Article DE germ-cell stage; spermatogonial mutations; deletions; specific-locus test; dominant-lethal test ID DOMINANT LETHAL MUTATIONS; INDUCED SPECIFIC-LOCUS; GERM-LINE MUTATIONS; DILUTION P LOCUS; MALE-MICE; COMPLEMENTATION ANALYSES; MOLECULAR ANALYSIS; FEMALE MICE; CELL STAGES; INDUCTION AB Dominant-lethal tests [P.D. Sudman, J,C. Rutledge, J.B. Bishop, W.M. Generoso, Bleomycin: female-specific dominant lethal effects in mice, Mutat. Res. 296 (1992) 205-217] had suggested that Bleomycin sulfate (Blenoxane), BLM, might be a female-specific mutagen. While confirming that BLM is indeed a powerful inducer of dominant-lethal mutations in females that fails to induce such mutations in postspermatogonial stages of males, we have shown in a specific-locus test that BLM is, in fact, mutagenic in males. This mutagenicity, however, is restricted to spermatogonia (stem-cell and differentiating stages), fur which the specific-locus mutation rate differed significantly (P < 0.008) from the historical control rate. In treated groups, dominant mutations, also, originated only in spermatogonia. With regard to mutation frequencies, this germ-cell-stage pattern is different from that for radiation and fur any other chemical studied to date, except ethylnitrosourea (ENU). However, the nature of the spermatogonial specific-locus mutations differentiates BLM from ENU as well, because BLM induced primarily (or, perhaps, exclusively) multilocus deletions. Heretofore, no chemical that induced specific-locus mutations in spermatogonia did not also induce specific-locus as well as dominant-lethal mutations in postspermatogonial stages, making the dominant lethal test, up till now, predictive of male mutagenicity in general. The BLM results now demonstrate that there are chemicals that can induce specific-locus mutations in spermatogonia without testing positive in postspermatogonial stages. Thus, BLM, while not female-specific, is unique, (a) in its germ-cell-stage specificity in males, and (b) in inducing a type of mutation (deletions) that is atypical for the responding germ-cell stages (spermatogonia). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. NIEHS, Res Triangle Pk, NC 27709 USA. RP Russell, LB (reprint author), Oak Ridge Natl Lab, Div Life Sci, Bldg 9210,POB 2009,MS 8077, Oak Ridge, TN 37831 USA. EM russelllb@ornl.gov FU NIEHS NIH HHS [Y1-ES-8048/O524-I119-AI] NR 41 TC 12 Z9 12 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1383-5718 J9 MUTAT RES-GEN TOX EN JI Mutat. Res. Genet. Toxicol. Environ. Mutagen. PD AUG 21 PY 2000 VL 469 IS 1 BP 95 EP 105 DI 10.1016/S1383-5718(00)00060-7 PG 11 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 350FY UT WOS:000089091300010 PM 10946246 ER PT J AU Quigg, C AF Quigg, C TI Questions of identity SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT ICFA/ECFA Workshop on Neutrino Factories based on muon Storage Rings (vFACT 99) CY JUL 05-09, 1999 CL LYON, FRANCE SP ICFA, ECFA DE NUFACT99; neutrino; oscillations; lyon; flavor ID DYNAMICAL SYMMETRY BREAKING; NEUTRINO OSCILLATIONS; ATMOSPHERIC NEUTRINOS; PARTICLE PHYSICS; LSND EXPERIMENT; STANDARD MODEL; DECAY; NU(MU)<-->NU(TAU); MASS AB As an introduction to vFact '99, the ICFA/ECFA Workshop on Neutrino Factories Based on Muon Storage Rings, I place the issues of neutrino properties and neutrino oscillations in the broader context of fermion flavor. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP Quigg, C (reprint author), Fermi Natl Accelerator Lab, Dept Theoret Phys, POB 500, Batavia, IL 60510 USA. NR 74 TC 5 Z9 5 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 2000 VL 451 IS 1 BP 1 EP 9 DI 10.1016/S0168-9002(00)00366-1 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 355LG UT WOS:000089386700002 ER PT J AU Harris, DA Para, A AF Harris, DA Para, A TI Neutrino oscillation appearance experiment using nuclear emulsion and magnetized iron SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT ICFA/ECFA Workshop on Neutrino Factories based on muon Storage Rings (vFACT 99) CY JUL 05-09, 1999 CL LYON, FRANCE SP ICFA, ECFA AB This report describes an apparatus that could be used to measure both the identity and charge of an outgoing lepton in a charged current neutrino interaction. This capability in a massive detector would allow the most comprehensive set of neutrino oscillation physics measurements. By measuring the six observable transitions between initial and final state neutrinos, one would be able to measure all elements of the neutrino mixing matrix, as well as search for CP violation, and matter effects. If the measured matrix is not unitary, then one would also have an unambiguous determination of sterile neutrinos. Emulsion is considered as the tracking medium, and different techniques are discussed for the application of a magnetic field. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Rochester, Rochester, NY 14853 USA. RP Harris, DA (reprint author), Fermi Natl Accelerator Lab, POB 500,MS220, Batavia, IL 60510 USA. NR 5 TC 4 Z9 4 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 2000 VL 451 IS 1 BP 173 EP 175 DI 10.1016/S0168-9002(00)00382-X PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 355LG UT WOS:000089386700023 ER PT J AU King, BJ AF King, BJ TI High-rate neutrino detectors for neutrino factories SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT ICFA/ECFA Workshop on Neutrino Factories based on muon Storage Rings (vFACT 99) CY JUL 05-09, 1999 CL LYON, FRANCE SP ICFA, ECFA DE NUFACT99; detectors; Muon Colliders; neutrino factories; CKM; charm AB Three types of high-rate neutrino detectors for neutrino interaction physics at neutrino factories are discussed. High-performance general-purpose detectors might collect event samples of the order of a billion events or more. This could greatly improve on the existing analyses of neutrino interactions and also lead to new and important analysis topics including, for example, precise determinations of the CKM matrix elements \V-ub\ and \V-cb\. The potential of such general-purpose detectors is illustrated with reference to a previously discussed detector (B.J. King, Neutrino physics at a Muon Colliders, Proceedings of the Workshop on Physics at the First Muon Collider and Front End of a Muon Collider, Fermilab, November 6-9, 1997) that is structured around a novel and compact vertexing and tracking neutrino target comprising a stack of CCD pixel devices. Design ideas and prospects are also discussed for two types of specialized detectors: (i) polarized targets filled with polarized solid protium-deuterium (HD), for unique and powerful studies of the nucleon's spin structure, and (ii) fully active liquid tracking targets with masses of several tonnes for precise determinations of the weak mixing angle, sin(2) theta(W), from the total cross-section for neutrino-electron scattering. All three detector types pose severe technical challenges but their utilization could add significantly to the physics motivation for neutrino factories. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP King, BJ (reprint author), Brookhaven Natl Lab, POB 5000, Upton, NY 11973 USA. NR 13 TC 4 Z9 4 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 2000 VL 451 IS 1 BP 198 EP 206 DI 10.1016/S0168-9002(00)00387-9 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 355LG UT WOS:000089386700028 ER PT J AU Geer, S Johnstone, C Neuffer, D AF Geer, S Johnstone, C Neuffer, D TI Design concepts for a muon storage ring neutrino source SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT ICFA/ECFA Workshop on Neutrino Factories based on muon Storage Rings (vFACT 99) CY JUL 05-09, 1999 CL LYON, FRANCE SP ICFA, ECFA AB We described a preliminary design study for a muon storage ring neutrino source that could be built as a step towards the first muon collider. In our design the neutrino beam is produced by 3 x 10(20) muon decays per year occurring within the straight section of a muon storage ring, and that intensity could be increased by upgrading the proton source intensity. The resulting neutrino flux is sufficient to produce hundreds of charged current interactions per year in a reasonable sized detector on the other side of the Earth. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Neuffer, D (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 15 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 2000 VL 451 IS 1 BP 255 EP 264 DI 10.1016/S0168-9002(00)00392-2 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 355LG UT WOS:000089386700035 ER PT J AU Palmer, RB Johnson, C Keil, E AF Palmer, RB Johnson, C Keil, E TI A cost-effective design for a neutrino factory SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT ICFA/ECFA Workshop on Neutrino Factories based on muon Storage Rings (vFACT 99) CY JUL 05-09, 1999 CL LYON, FRANCE SP ICFA, ECFA AB The design of a neutrino factory based on a muon storage ring draws upon several tried and tested technologies, upon existing design work For other accelerator projects, e.g. neutron spallation sources, but it also depends on the development of technical solutions to certain specific requirements. These include the efficient capture of muons in a large volume of phase-space, some reduction in overall phase-space volume by ionization cooling, fast acceleration to the desired energy to avoid unacceptable decay losses and storage in a decay ring optimized for its purpose as a neutrino source. There is Ilo obvious single combination of machines to achieve this aim. Here we present a scenario which relies to a large extent upon known technologies together with a relatively unambitious mix of new schemes. Some will be tried and tested during design and construction; others during the early operational phase of the facility leading to a staged upgrade path - a well-proven strategy in the development of accelerator complexes. (C) 2000 Elsevier Science B.V. All rights reserved. C1 CERN, Geneva, Switzerland. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Keil, E (reprint author), CERN, Geneva, Switzerland. NR 20 TC 17 Z9 17 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 2000 VL 451 IS 1 BP 265 EP 278 DI 10.1016/S0168-9002(00)00393-4 PG 14 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 355LG UT WOS:000089386700036 ER PT J AU Wilson, EJN Sessler, AM AF Wilson, EJN Sessler, AM TI Summary of scenarios working groups SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT ICFA/ECFA Workshop on Neutrino Factories based on muon Storage Rings (vFACT 99) CY JUL 05-09, 1999 CL LYON, FRANCE SP ICFA, ECFA DE neutrino factory; muon collection; scenario; polarization AB Three scenarios for a neutrino factory were discussed at the workshop. All were based upon muon collider studies differing principally in the proton driver each assumed. Differing assumptions concerning power on target, bunch structure and the use of cooling were ironed out, leaving one basic scenario downstream of the target. A list of R&D topics was compiled and prioritized. (C) 2000 Elsevier Science B.V. All rights reserved. C1 CERN, CH-1211 Geneva 23, Switzerland. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Wilson, EJN (reprint author), CERN, CH-1211 Geneva 23, Switzerland. NR 4 TC 0 Z9 0 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 2000 VL 451 IS 1 BP 279 EP 286 DI 10.1016/S0168-9002(00)00394-6 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 355LG UT WOS:000089386700037 ER PT J AU Collot, J Kirk, HG Mokhov, NV AF Collot, J Kirk, HG Mokhov, NV TI Pion production models and neutrino factories SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT ICFA/ECFA Workshop on Neutrino Factories based on muon Storage Rings (vFACT 99) CY JUL 05-09, 1999 CL LYON, FRANCE SP ICFA, ECFA DE target fragmentation; particle sources; targets AB Scenarios For the building of muon colliders or storage rings suitable for the generation of robust neutrino beams call for the generation of a prodigious quantity of pions. These pions are then conducted into a decay channel where the resulting muon decay products can be collected for cooling and subsequent acceleration. Central to this concept is the design and construction of a target which will be highly efficient in producing pions of both signs while mitigating the absorption of these pions before they decay. This design effort is being facilitated by using two computer codes FLUKA and MARS. We present comparisons of the two computer codes acid also present a comparison of these codes with available data. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Grenoble 1, CNRS, IN2P3, ISN, Grenoble, France. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Kirk, HG (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 12 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 2000 VL 451 IS 1 BP 327 EP 330 DI 10.1016/S0168-9002(00)00399-5 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 355LG UT WOS:000089386700043 ER PT J AU King, BJ AF King, BJ TI Rotating band pion production targets for muon colliders and neutrino factories SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT ICFA/ECFA Workshop on Neutrino Factories based on muon Storage Rings (vFACT 99) CY JUL 05-09, 1999 CL LYON, FRANCE SP ICFA, ECFA DE NUFACT99; targetry; muon colliders; neutrino factories AB An update is presented on a conceptual design for a pion production target station using a rotating cupronickel band and that was originally proposed for use at a muon collider facility with a 4 MW pulsed proton beam. After reviewing the salient design features and motivations for this target, ongoing studies are described that are attempting to benchmark the thermal stresses and radiation damage on the target band using data from the Fermilab antiproton source and other operating targets. Possible parameter optimizations and alternative technologies for the rotating band are surveyed, including discussion on the the various proton beam parameters that might be: encountered for rotating band targets at either muon colliders or neutrino factories. Finally, an outline is proposed for a possible R&D path towards capability for the actual construction of rotating band pion production targets. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP King, BJ (reprint author), Brookhaven Natl Lab, POB 5000, Upton, NY 11973 USA. NR 20 TC 2 Z9 2 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 2000 VL 451 IS 1 BP 335 EP 343 DI 10.1016/S0168-9002(00)00402-2 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 355LG UT WOS:000089386700045 ER PT J AU Neuffer, D AF Neuffer, D TI RF capture variations for the muon storage ring neutrino source SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT ICFA/ECFA Workshop on Neutrino Factories based on muon Storage Rings (vFACT 99) CY JUL 05-09, 1999 CL LYON, FRANCE SP ICFA, ECFA AB We present possible scenarios for capturing the long bunches of a muon source into a string of high-frequency bunches for cooling and acceleration into a muon storage ring for neutrinos. A matched solution using double-harmonic RF appears appropriate to the Palmer neutrino source scenario (R. Palmer, Muon Collider Note 46, 9/3/99, Proceedings of Lyon Workshop oil Neutrino Factories); however, different scenarios (i.e., with single stage RF rotation) may prefer an adiabatic solution to minimize phase-space dilution. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Accelerator Div, Batavia, IL 60510 USA. RP Neuffer, D (reprint author), Fermi Natl Accelerator Lab, Accelerator Div, POB 500,MS 220, Batavia, IL 60510 USA. NR 3 TC 0 Z9 0 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 2000 VL 451 IS 1 BP 367 EP 374 DI 10.1016/S0168-9002(00)00409-5 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 355LG UT WOS:000089386700051 ER PT J AU Johnstone, C Ohnuma, S AF Johnstone, C Ohnuma, S TI Large acceptance 30 GeV muon storage rings for neutrino production: lattice design SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT ICFA/ECFA Workshop on Neutrino Factories based on muon Storage Rings (vFACT 99) CY JUL 05-09, 1999 CL LYON, FRANCE SP ICFA, ECFA DE NUFACT99; neutrino; ring; lyon; factory AB Two competing goals control the lattice design of a muon storage ring for a neutrino factory [1]. One goal is achieving large transverse and longitudinal acceptances in order to minimize the degree of muon-beam cooling required. (This condition presumes large-emittance muon beams can be effectively accelerated.) The second is provision of a long insertion in which a significant fraction of the stored muons decay and produce a relatively colinear beam of neutrinos. In this work, a 30 GeV muon storage ring is presented which is optimized for acceptance acid maximal neutrino-beam production. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Houston, Houston, TX USA. RP Johnstone, C (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 5 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 2000 VL 451 IS 1 BP 379 EP 384 DI 10.1016/S0168-9002(00)00412-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 355LG UT WOS:000089386700053 ER PT J AU Yeston, JS McNamara, BK Bergman, RG Moore, CB AF Yeston, JS McNamara, BK Bergman, RG Moore, CB TI Flash infrared kinetics of the photochemistry of Tp*Rh(CO)(2) and Bp*Rh(CO)(2) in liquid xenon solution SO ORGANOMETALLICS LA English DT Article ID H BOND ACTIVATION; METAL-CARBONYL-COMPLEXES; CO SUBSTITUTION KINETICS; RESOLVED IR SPECTROSCOPY; NOBLE-GAS; (HBPZ'(3))RH(CO)(2) PZ'=3,5-DIMETHYLPYRAZOLYL; ROOM-TEMPERATURE; RARE-GASES; RHODIUM; XE AB The photochemistry of Tp*Rh(CO)(2) (1; Tp* = hydridotris(3,5-dimethylpyrazolyl)borate) in liquid xenon solution at -50 degrees C has been examined by flash IR kinetic spectroscopy. IR spectra of the solution taken 2 mu s after 308 nm photolysis exhibit two transient bands at 1976-1980 and. 1994-1998 cm(-1), respectively, both of which decay with the same first-order rate constant (k = 2 x 10(4) s(-1)). In the presence of excess CO, the rates of decay of both of these bands increase by an order of magnitude and correlate with the rate of recovery of the CO stretch of the parent complex. Photolysis of xenon solutions of Bp*Rh(CO)(2) (5; Bp* = dihydridobis(3,5-dimethylpyrazolyl)borate) produces a transient species with a single IR absorption at 1996-2000 cm(-1). Upon addition of pyridine to the solution, this transient photoproduct reacts to form the new, stable complex Bp*Rh(CO)(pyridine), with an IR absorption at 1978 cm(-1). On the basis of these results, the 1978 and 1996 cm(-1) bands observed upon photolysis of 1 are attributed to the solvates (eta(3)-Tp*)Rh(CO).Xe and (eta(2)-Tp*)Rh(CO). Xe (2 Xe and 3 Xe, respectively). Preliminary kinetic data for the reaction of 1 with cyclohexane in xenon solution indicate that both the 1978 and 1996 cm(-1) transient bands still appear and that their rates of decay correlate with formation of the Ph alkyl hydride product Tp*Rh(CO)(cyclohexyl)(H) (4), absorbing at 2032 cm(-1). C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Bergman, RG (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 30 TC 22 Z9 22 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD AUG 21 PY 2000 VL 19 IS 17 BP 3442 EP 3446 DI 10.1021/om000238w PG 5 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 347YF UT WOS:000088956200027 ER PT J AU Fujiwara, MC Adamczak, A Bailey, JM Beer, GA Beveridge, JL Faifman, MP Huber, TM Kammel, P Kim, SK Knowles, PE Kunselman, AR Maier, M Markushin, VE Marshall, GM Martoff, CJ Mason, GR Mulhauser, F Olin, A Petitjean, C Porcelli, TA Wozniak, J Zmeskal, J AF Fujiwara, MC Adamczak, A Bailey, JM Beer, GA Beveridge, JL Faifman, MP Huber, TM Kammel, P Kim, SK Knowles, PE Kunselman, AR Maier, M Markushin, VE Marshall, GM Martoff, CJ Mason, GR Mulhauser, F Olin, A Petitjean, C Porcelli, TA Wozniak, J Zmeskal, J CA TRIUMF Muonic Hydrogen Collaborati TI Resonant formation of d mu t molecules in deuterium: An atomic beam measurement of muon catalyzed dt fusion SO PHYSICAL REVIEW LETTERS LA English DT Article ID TIME-OF-FLIGHT; SOLID HYDROGEN; TRITIUM; GAS; EMISSION; MIXTURES; VACUUM; SYSTEM AB Resonant formation of d mu t molecules in collisions of muonic tritium (mu t) on D-2 was investigated using a beam of mu t atoms, demonstrating a new direct approach in muon catalyzed fusion studies. Strong epithermal resonances in d mu t formation were directly revealed fur the first time. From the time-of-flight analysis of 2036 +/- 116 dt fusion events, a formation rate consistent with 0.73 +/- (0.16)(meas) +/- (0.09)(model) times the theoretical prediction was obtained. For the largest peak at a resonance energy of 0.423 +/- 0.037 eV, this corresponds to a rate of (7.1 +/- 1.8) X 10(9) s(-1), more than an order of magnitude target than those at low energies. C1 Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 2A6, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. Inst Nucl Phys, PL-31342 Krakow, Poland. Chester Technol, Chester CH4 7QH, Cheshire, England. Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 2Y2, Canada. IV Kurchatov Atom Energy Inst, Russian Res Ctr, Moscow 123182, Russia. Gustavus Adolphus Coll, Dept Phys, St Peter, MN 56082 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Jeonbuk Natl Univ, Dept Phys, Jeonju 560756, South Korea. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Temple Univ, Dept Phys, Philadelphia, PA 19122 USA. Stanislaw Staszic Univ Min & Met, Fac Phys & Nucl Tech, PL-30059 Krakow, Poland. Austrian Acad Sci, Inst Medium Energy Phys, A-1090 Vienna, Austria. RP Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 2A6, Canada. EM Makoto.Fujiwara@cern.ch NR 49 TC 21 Z9 21 U1 0 U2 0 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 AUG 21 PY 2000 VL 85 IS 8 BP 1642 EP 1645 DI 10.1103/PhysRevLett.85.1642 PG 4 WC Physics, Multidisciplinary SC Physics GA 345ZT UT WOS:000088846100015 ER PT J AU Spoor, PS Swift, GW AF Spoor, PS Swift, GW TI Thermoacoustic separation of a He-Ar mixture SO PHYSICAL REVIEW LETTERS LA English DT Article ID DIFFUSION; GASES; FLOW AB We report observation of a new mixture-separation process: an insonified mixture of helium and argon in a narrow duct spatially separates along the acoustic-propagation axis. We measure mole-fraction differences across the ends of the duct as large as 7%. We measure initial separation flux densities as high as 10(-3) M-2 c, where M is the acoustic Mach number and c is the sound speed. This initial separation flux, as a function of both the amplitudes and the relative phasing of the pressure and velocity oscillations in the duct: agrees well with a recent theory involving oscillatings thermal diffusion in the acoustic boundary layer. C1 Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Spoor, PS (reprint author), Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, POB 1663, Los Alamos, NM 87545 USA. NR 17 TC 17 Z9 19 U1 6 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 21 PY 2000 VL 85 IS 8 BP 1646 EP 1649 DI 10.1103/PhysRevLett.85.1646 PG 4 WC Physics, Multidisciplinary SC Physics GA 345ZT UT WOS:000088846100016 ER PT J AU Labaune, C Baldis, HA Schifano, E Bauer, BS Maximov, A Ourdev, I Rozmus, W Pesme, D AF Labaune, C Baldis, HA Schifano, E Bauer, BS Maximov, A Ourdev, I Rozmus, W Pesme, D TI Enhanced forward scattering in the case of two crossed laser beams interacting with a plasma SO PHYSICAL REVIEW LETTERS LA English DT Article ID STIMULATED BRILLOUIN-SCATTERING; INERTIAL CONFINEMENT FUSION; ENERGY-TRANSFER; UNDERDENSE PLASMAS; FLOWING PLASMA; POWER TRANSFER; FILAMENTATION; INSTABILITIES AB The nonlinear enhancement of large-angle forward scattering of two identical laser beams propagating in a preformed plasma has been observed experimentally. The spectral analysis of the forward-scattered light shows two components, one which is unshifted with respect to the initial laser light frequency, and the other which is redshifted by a few angstroms. The redshifted component is found to be strongly enhanced in the case of crossed beam interaction in comparison with that of one beam illumination. Two-dimensional numerical simulations show that this enhancement is due to large-angle forward stimulated Brillouin scattering in which each beam serves as seed for the forward scattering of the other. C1 Ecole Polytech, CNRS, Lab Utilisat Lasers Intenses, F-91128 Palaiseau, France. Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Appl, Livermore, CA 94550 USA. Univ Alberta, Dept Phys, Inst Theoret Phys, Edmonton, AB T6G 2J1, Canada. Ecole Polytech, CNRS, Ctr Phys Theor, F-91128 Palaiseau, France. RP Labaune, C (reprint author), Ecole Polytech, CNRS, Lab Utilisat Lasers Intenses, F-91128 Palaiseau, France. NR 21 TC 24 Z9 24 U1 2 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 21 PY 2000 VL 85 IS 8 BP 1658 EP 1661 DI 10.1103/PhysRevLett.85.1658 PG 4 WC Physics, Multidisciplinary SC Physics GA 345ZT UT WOS:000088846100019 ER PT J AU Muller, J Liu, B Shvartsburg, AA Ogut, S Chelikowsky, JR Siu, KWM Ho, KM Gantefor, G AF Muller, J Liu, B Shvartsburg, AA Ogut, S Chelikowsky, JR Siu, KWM Ho, KM Gantefor, G TI Spectroscopic evidence for the tricapped trigonal prism structure of semiconductor clusters SO PHYSICAL REVIEW LETTERS LA English DT Article ID SIZED SILICON CLUSTERS; PHOTOELECTRON-SPECTROSCOPY; FINITE-TEMPERATURE; ELECTRONIC-STRUCTURES; ANIONS; SPECTRA; GEOMETRIES; SI; GERMANIUM; CATIONS AB We have obtained photoelectron spectra (PES) for silicon cluster anions with up to 20 atoms. Efficient cooling of species in the source has allowed us to resolve multiple features in the PES fur all sizes studied. Spectra for an extensive set of low-energy Si-n(-) isomers found by a global search have been simulated using density functional theory and pseudopotentials. Except for n = 12, calculations for Si-n(-) ground states agree with the measurements. This does not hold for other plausible geometries, Hence PES data validate the tricapped trigonal prism morphologies for medium-sized Si clusters. C1 Univ Konstanz, Fachbereich Phys, D-78457 Constance, Germany. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. York Univ, Dept Chem, N York, ON M3J 1P3, Canada. York Univ, Ctr Res Mass Spect, N York, ON M3J 1P3, Canada. Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. RP Muller, J (reprint author), Univ Konstanz, Fachbereich Phys, D-78457 Constance, Germany. RI Ogut, Serdar/B-1749-2012 NR 30 TC 77 Z9 79 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 21 PY 2000 VL 85 IS 8 BP 1666 EP 1669 DI 10.1103/PhysRevLett.85.1666 PG 4 WC Physics, Multidisciplinary SC Physics GA 345ZT UT WOS:000088846100021 ER PT J AU Jhi, SH Louie, SG Cohen, ML AF Jhi, SH Louie, SG Cohen, ML TI Electronic properties of oxidized carbon nanotubes SO PHYSICAL REVIEW LETTERS LA English DT Article ID GRAPHITE; ENERGY AB The effect of oxygenation on the electronic properties of semiconducting carbon nanotubes is studied from first principles. The O-2 is found to bind to a single-walled nanotube with an adsorption energy of about 0.25 eV and to dope semiconducting nanotubes with hole carriers. Weak hybridization between carbon and oxygen is predicted for the valence-band edge states. The calculated density of states shows that weak coupling leads to conducting states near the band gap. The oxygen-induced gap closing for large-diameter semiconducting tubes is discussed as well. The influence of oxygen on the magnetic property is also addressed through a spin-polarized calculation and compared to experiment. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Jhi, SH (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 15 TC 353 Z9 361 U1 6 U2 49 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 21 PY 2000 VL 85 IS 8 BP 1710 EP 1713 DI 10.1103/PhysRevLett.85.1710 PG 4 WC Physics, Multidisciplinary SC Physics GA 345ZT UT WOS:000088846100032 ER PT J AU Ichikawa, N Uchida, S Tranquada, JM Niemoller, T Gehring, PM Lee, SH Schneider, JR AF Ichikawa, N Uchida, S Tranquada, JM Niemoller, T Gehring, PM Lee, SH Schneider, JR TI Local magnetic order vs superconductivity in a layered cuprate SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; EARTH-DOPED LA2-XSRXCUO4; CHARGE-STRIPE ORDER; FERMI-LIQUID; PHASE; LA1.48ND0.4SR0.12CUO4; FLUCTUATIONS; SUBSTITUTION; SPINS; HOLES AB We report on the phase diagram for charge-stripe order in La1.6-xNd0.4SrxCuO4, determined by neutron and x-ray scattering studies and resistivity measurements. From an analysis of the in-plane resistivity motivated by recent nuclear-quadrupole-resonance studies, we conclude that the transition temperature for local charge ordering decreases monotonically with x, and hence that local antiferromagnetic order is uniquely correlated with the anomalous depression of superconductivity at x approximate to 1/8. This result is consistent with theories in which superconductivity depends on the existence of charge-stripe correlations. C1 Univ Tokyo, Sch Engn, Dept Superconduct, Bunkyo Ku, Tokyo 1138656, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. DESY, Hamburger Synchrotronstrahlungslabor, HASYLAB, D-22603 Hamburg, Germany. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. RP Ichikawa, N (reprint author), Kyoto Univ, Inst Chem Res, Uji 6110011, Japan. RI Tranquada, John/A-9832-2009; OI Tranquada, John/0000-0003-4984-8857; Gehring, Peter/0000-0002-9236-2046 NR 33 TC 189 Z9 190 U1 2 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 21 PY 2000 VL 85 IS 8 BP 1738 EP 1741 DI 10.1103/PhysRevLett.85.1738 PG 4 WC Physics, Multidisciplinary SC Physics GA 345ZT UT WOS:000088846100039 ER PT J AU Alonso, CT AF Alonso, CT TI Discovery and naming of element 106 (seaborgium). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 5-NUCL BP U3 EP U3 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300006 ER PT J AU Anderson, BB Mahannah, RN Sharma, VC Sanders, MA AF Anderson, BB Mahannah, RN Sharma, VC Sanders, MA TI Simultaneous ultraviolet-visible spectroscopic determination of plutonium and uranium in mixed oxides. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 54-NUCL BP U11 EP U11 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300055 ER PT J AU Anderson, BB Serkiz, SM Powell, KR McCarty, JE Sanders, MA AF Anderson, BB Serkiz, SM Powell, KR McCarty, JE Sanders, MA TI Utilization of a novel surface plasmon resonance probe for gas and liquid phase chemical sensing. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 26-NUCL BP U6 EP U6 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300027 ER PT J AU Angelici, RJ Gao, HR AF Angelici, RJ Gao, HR TI Rhodium complexes tethered on gold particles as catalysts for the hydrogenation of olefins. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 432-INOR BP U517 EP U517 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202795 ER PT J AU Anghel, I Reimus, PW AF Anghel, I Reimus, PW TI Colloid transport in fractured rock: Comparison of polystyrene and silica microspheres. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 43-COLL BP U232 EP U232 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201179 ER PT J AU Atkinson, DA Miller, CJ Daum, KA Ewing, RG AF Atkinson, DA Miller, CJ Daum, KA Ewing, RG TI Explosives detection using ion mobility spectrometry: What's next?. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 0 TC 0 Z9 0 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 136-ANYL BP U99 EP U99 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200463 ER PT J AU Bakac, A AF Bakac, A TI Reactions of carbon- and oxygen-centered radicals with transition metal complexes in aqueous solution. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 332-INOR BP U503 EP U503 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202698 ER PT J AU Baldelli, S Mailhot, G Ross, P Shen, YR Somorjai, GA AF Baldelli, S Mailhot, G Ross, P Shen, YR Somorjai, GA TI Potential dependent orientation of acetonitrile at the PT(111) electrode interface studied with sum frequency generation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Blaise Pascal, CNRS, UMR 6505, Photochim Mol & Macromol Lab, Aubiere, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 188-COLL BP U254 EP U254 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201324 ER PT J AU Barger, JR Tebo, BM Pecher, KH Chiu, V Villinski, JE Tonner, BP AF Barger, JR Tebo, BM Pecher, KH Chiu, V Villinski, JE Tonner, BP TI Kinetics and products of Mn oxide biomineralization by spores of the marine Bacillus, sp strain SG-1. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Stanford Synchrotron Radiat Lab, Stanford, CA USA. Univ Calif San Diego, Scripps Inst Oceanog, Div Marine Biol Res, La Jolla, CA 92093 USA. Univ Cent Florida, Dept Phys, Orlando, FL USA. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 105-ENVR BP U332 EP U332 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201727 ER PT J AU Bartelt, M AF Bartelt, M TI Simulations of submonolayer epitaxy and etching. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Sandia Natl Labs, Mat Modeling Dept, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 74-COLL BP U236 EP U236 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201210 ER PT J AU Becker, A Klock, W Duff, MC AF Becker, A Klock, W Duff, MC TI Heavy metal species in sediments of Lake Susser See, Germany. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Halle Wittenberg, Inst Geol Sci, D-06108 Halle, Germany. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 221-ENVR BP U351 EP U351 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201843 ER PT J AU Beecy, DJ Ferrell, F Carey, J AF Beecy, DJ Ferrell, F Carey, J TI Potential role of geologic storage of carbon dioxide in a sustainable longer term fossil fuels future. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US DOE, Off Fossil Energy, DOE FE 23, Germantown, MD 20874 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 80-FUEL BP U397 EP U397 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202110 ER PT J AU Bittner, EW Smith, MR Bockrath, BC AF Bittner, EW Smith, MR Bockrath, BC TI Characterization of adsorption on carbon nanotubes using a pulse mass analyzer. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 104-FUEL BP U401 EP U401 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202134 ER PT J AU Blanchard, DL Kurath, DE Rapko, BM Bontha, JR Johnson, ME AF Blanchard, DL Kurath, DE Rapko, BM Bontha, JR Johnson, ME TI Testing of Superlig (R) 639 for Tc removal from Hanford tank wastes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Battelle Pacific Northwest Div, Environm Technol Div, Radiochem Proc Grp, Richland, WA 99352 USA. Battelle Pacific Northwest Div, Environm Technol Div, Chem Separat & Slurry Proc Grp, Richland, WA USA. BNFL Inc, Fairfax, VA USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 87-IEC BP U425 EP U425 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202264 ER PT J AU Bliss, M Bowyer, SM Bryant, JL Clauss, TRW Wahl, KL AF Bliss, M Bowyer, SM Bryant, JL Clauss, TRW Wahl, KL TI Experiences and management of pregnant radiation workers at the Pacific Northwest National Laboratory. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RI Bliss, Mary/G-2240-2012 OI Bliss, Mary/0000-0002-7565-4813 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 14-CHAS BP U189 EP U189 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200967 ER PT J AU Boll, RA Glasgow, DC Mirzadeh, S AF Boll, RA Glasgow, DC Mirzadeh, S TI NAA quality control of actinium-225 for medical applications. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RI Boll, Rose/C-4138-2016 OI Boll, Rose/0000-0003-2507-4834 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 148-NUCL BP U24 EP U24 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300148 ER PT J AU Bond, AH Nash, KL Gelis, AV Jensen, MP AF Bond, AH Nash, KL Gelis, AV Jensen, MP TI Actinide release and matrix dissolution during experimental washing of Hanford sludge waste simulants. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 55-IEC BP U420 EP U421 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202232 ER PT J AU Bond, AH Nash, KL AF Bond, AH Nash, KL TI Join the separation science and technology subdivision of the ACS I&EC division! SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 32-IEC BP U417 EP U417 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202209 ER PT J AU Bowyer, TW Hayes, JC Reeder, PL Panisko, ME Pitts, WK McIntyre, JI Abel, KH Thompson, RC Heimbigner, TR Warner, RA AF Bowyer, TW Hayes, JC Reeder, PL Panisko, ME Pitts, WK McIntyre, JI Abel, KH Thompson, RC Heimbigner, TR Warner, RA TI Automated Radioxenon Sampler-Analyzer: Detection of radioactive xenon for the CTBT. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RI McIntyre, Justin/P-1346-2014 OI McIntyre, Justin/0000-0002-3706-4310 NR 0 TC 0 Z9 0 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 101-NUCL BP U17 EP U17 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300101 ER PT J AU Brown, DW AF Brown, DW TI Geothermal power production utilizing supercritical CO2 combined with deep earth carbon sequestration. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 94-FUEL BP U399 EP U399 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202124 ER PT J AU Brown, GM Bell, ZW Ho, CH Sloop, FV AF Brown, GM Bell, ZW Ho, CH Sloop, FV TI Gadolinium and boron-loaded silicone rubber scintillators. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Lockheed Martin Energy Syst, Oak Ridge, TN USA. RI Sloop, Jr., Frederick/J-2301-2016 OI Sloop, Jr., Frederick/0000-0001-6473-9507 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 153-NUCL BP U25 EP U25 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300153 ER PT J AU Buchanan, AC Britt, PF Koran, LJ AF Buchanan, AC Britt, PF Koran, LJ TI Thermolysis pathways for surface-immobilized diarylmethanes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 277-ORGN BP U76 EP U76 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300443 ER PT J AU Buchanan, MV AF Buchanan, MV TI Analytical chemistry at the interface of multidisciplinary science. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 143-ANYL BP U100 EP U100 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200470 ER PT J AU Buchholz, BA Haack, KW Vogel, JS Gilman, SD Gee, S Hammock, BD Wester, RC Hui, XY Maibach, HI AF Buchholz, BA Haack, KW Vogel, JS Gilman, SD Gee, S Hammock, BD Wester, RC Hui, XY Maibach, HI TI Measuring biomarkers of dermal exposure to atrazine in human urine using HPLC-accelerator MS. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RI Buchholz, Bruce/G-1356-2011; Gilman, Samuel/D-1635-2016 OI Gilman, Samuel/0000-0001-7208-3894 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 58-AGRO BP U55 EP U56 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200211 ER PT J AU Buchholz, BA Keating, GA Vogel, JS AF Buchholz, BA Keating, GA Vogel, JS TI Deposition of organophosphates in blood and brain tissue after low level exposure. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Buchholz, Bruce/G-1356-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 123-NUCL BP U21 EP U21 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300123 ER PT J AU Carpick, RW Sasaki, DY Burns, AR AF Carpick, RW Sasaki, DY Burns, AR TI Nanometer-scale structural, tribological, and optical properties of ultrathin poly(diacetylene) films. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Wisconsin, Madison, WI 53706 USA. Sandia Natl Labs, Biomol Mat & Interfaces Dept, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 247-POLY BP U292 EP U292 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301646 ER PT J AU Cary, DR O'Day, KE Bowers, AJ Zaitseva, NP Darrow, CB Lane, SM Peyser, TA Satcher, JH Heiss, AM Vachon, D AF Cary, DR O'Day, KE Bowers, AJ Zaitseva, NP Darrow, CB Lane, SM Peyser, TA Satcher, JH Heiss, AM Vachon, D TI New small-molecule glucose transducers based on naphthalimide dyes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. MiniMed Inc, Sylmar, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 43-ORGN BP U39 EP U39 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300209 ER PT J AU Chang, SG Huang, HP AF Chang, SG Huang, HP TI Dual alkaline approaches for the capture and disposal of carbon dioxide. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 44-FUEL BP U392 EP U392 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202075 ER PT J AU Charlton, WS Stanbro, WD Fearey, BL AF Charlton, WS Stanbro, WD Fearey, BL TI Determination of required instrument characteristics for on-stack stable noble gas monitoring. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Safeguard Syst Grp, Los Alamos, NM 87545 USA. US Dept Def, Off Arms Control & Implementat, Washington, DC USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 137-NUCL BP U23 EP U23 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300137 ER PT J AU Chen, J LeBoeuf, EJ Choi, SY Gu, BH AF Chen, J LeBoeuf, EJ Choi, SY Gu, BH TI Spectroscopic characterization of structural and functional properties of natural organic matter fractions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Vanderbilt Univ, Dept Civil & Environm Engn, Nashville, TN 37235 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 322-ENVR BP U366 EP U366 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201944 ER PT J AU Cheng, Q Zhu, SM Song, J Stevens, RC AF Cheng, Q Zhu, SM Song, J Stevens, RC TI Self-assembled redox amphiphilic vesicles on Au for the measurement of toxin binding. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 235-COLL BP U261 EP U262 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201370 ER PT J AU Chialvo, AA AF Chialvo, AA TI Molecular approach to solvation in highly compressible solvents. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Tennessee, Oak Ridge Natl Lab, Div Chem & Analyt Sci, Dept Chem Engn, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 188-PHYS BP U183 EP U183 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301006 ER PT J AU Chin, CJ Yiacoumi, S Tsouris, C AF Chin, CJ Yiacoumi, S Tsouris, C TI Aggregation of colloidal particles and breakup of aggregates. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Georgia Inst Technol, Sch Civil & Environm Engn, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 183-ENVR BP U345 EP U345 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201805 ER PT J AU Chitwood, DJ Johnson, MT Matonic, JH Ruggiero, GE Neu, MP AF Chitwood, DJ Johnson, MT Matonic, JH Ruggiero, GE Neu, MP TI Actinide complexes of microbially produced chelators. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 483-INOR BP U524 EP U524 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091202844 ER PT J AU Choi, SY Chen, J Gu, BH AF Choi, SY Chen, J Gu, BH TI Reductive dissolution of iron oxyhydroxides by different fractions of natural organic matter. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 319-ENVR BP U365 EP U366 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201941 ER PT J AU Chusuei, CC Goodman, DW Tarasevich, BJ Allara, DL Van Stipdonk, MJ English, RD Samples, CR Schweikert, EA AF Chusuei, CC Goodman, DW Tarasevich, BJ Allara, DL Van Stipdonk, MJ English, RD Samples, CR Schweikert, EA TI Cluster growth of hydroxyapatite on self-assembled monolayers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Texas A&M Univ, Dept Chem, College Stn, TX 77842 USA. Pacific NW Natl Lab, Div Mat Chem, Washington, DC 20010 USA. Penn State Univ, University Pk, PA 16802 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 124-COLL BP U244 EP U244 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201260 ER PT J AU Cochran, HD Salaniwal, S Cui, ST Cummings, PT AF Cochran, HD Salaniwal, S Cui, ST Cummings, PT TI Self-assembly of reverse micelles in supercritical CO2 by molecular dynamics simulation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 0 TC 1 Z9 1 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 145-COMP BP U298 EP U298 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091201596 ER PT J AU Collart, F AF Collart, F TI Identification of specific inhibitors of IMP dehydrogenase. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. Argonne Natl Lab, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 19-CARB BP U111 EP U111 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XU UT WOS:000166091200529 ER EF