FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Slominski, W Szwed, J AF Slominski, W Szwed, J TI On the electron structure function SO ACTA PHYSICA POLONICA B LA English DT Article ID PHOTON STRUCTURE; HARD SCATTERING; CROSS-SECTIONS; PHOTOPRODUCTION; HERA; APPROXIMATION; BOSONS AB The collinear QCD structure of the electron is studied within the Standard Model. The electron structure function is defined and calculated in leading logarithmic approximation. It shows important contribution from the interference of the intermediate electroweak bosons. The problem of momentum scales is extensively discussed. The master equations for the QCD parton densities inside the electron are constructed and solved numerically in the asymptotic region. Significant corrections to the naive evolution procedure are found. Phenomenological applications at present and future momentum scales are discussed. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Slominski, W (reprint author), JAGIELLONIAN UNIV,INST COMP SCI,REYMONTA 4,PL-30059 KRAKOW,POLAND. NR 23 TC 10 Z9 10 U1 0 U2 0 PU POLISH ACAD SCIENCES INST PHYSICS PI WARSAW PA AL LOTNIKOW 32-46, 02-668 WARSAW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD AUG PY 1996 VL 27 IS 8 BP 1887 EP 1913 PG 27 WC Physics, Multidisciplinary SC Physics GA VE918 UT WOS:A1996VE91800017 ER PT J AU Doebling, SW Peterson, LD Alvin, KF AF Doebling, SW Peterson, LD Alvin, KF TI Estimation of reciprocal residual flexibility from experimental modal data SO AIAA JOURNAL LA English DT Article ID STRUCTURAL DAMAGE DETECTION AB A technique is presented for estimating the residual flexibility between nonexcited structural degrees of freedom from experimental structural vibration data. Using this method, one can include the residual flexibility estimated from modal measurements in the computation of measured flexibility for experiments with incomplete reciprocity, i.e., when the response and excitation measurement sensors are not fully collocated. The method can also be used to estimate the unknown entries in the residual flexibility matrix for experimental component mode synthesis when excitations are not provided at all interface degrees of freedom. A general solution is presented that contains an unknown positive semidefinite contribution. The general solution satisfies modal orthogonality in the limit that all of the structural degrees of freedom are instrumented and when the positive semidefinite contribution lies in a nullspace defined by the stiffness matrix and the modal flexibility. With a limited number of measurements, modal orthogonality is shown to be satisfied to the extent that the measured modes are preserved by static condensation. A rank-deficient solution is presented that allows the residual to be used in the computation of the flexibility matrix without further modeling assumptions. Numerical and experimental results that demonstrate the application of the method to both flexibility matrix convergence and experimental component mode synthesis are presented. C1 UNIV COLORADO,DEPT AEROSP ENGN SCI,BOULDER,CO 80309. SANDIA NATL LABS,STRUCT DYNAM & VIBRAT CONTROL DEPT,ALBUQUERQUE,NM 87185. RP Doebling, SW (reprint author), LOS ALAMOS NATL LAB,DIV ENGN & APPL SCI,ENGN ANAL GRP,POB 1663,MAIL STOP P946,LOS ALAMOS,NM 87545, USA. NR 25 TC 37 Z9 37 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD AUG PY 1996 VL 34 IS 8 BP 1678 EP 1685 DI 10.2514/3.13289 PG 8 WC Engineering, Aerospace SC Engineering GA VA285 UT WOS:A1996VA28500020 ER PT J AU Sassi, AP Blanch, HW Prausnitz, JM AF Sassi, AP Blanch, HW Prausnitz, JM TI Phase equilibria for aqueous protein polyelectrolyte gel systems SO AICHE JOURNAL LA English DT Article ID POISSON-BOLTZMANN EQUATION; INTEGRAL-EQUATION; ACTIVITY-COEFFICIENTS; CONDENSATION THEORY; 2-PHASE SYSTEMS; DOUBLE-LAYER; WATER; MODEL; CHROMATOGRAPHY; ELECTROLYTES AB A molecular-thermodynamic analysis is directed toward predicting the partitioning of aqueous proteins into charged hydrogels. This analysis takes into account size exclusion by the network, electrostatic interactions, and the osmotic-pressure difference between a hydrogel and its surrounding solution. Electrostatic interactions in the polyelectrolyte gel can be described by Debye-Huckel theory, or the Mean Spherical Approximation, or Katchalsky's cell model for polyelectrolyte solutions. The cell model gives best agreement with experimental partition coefficients for cytochrome c. The quasi-electrostatic potential difference between a gel and its surrounding solution demonstrates how the electrostatic contribution to the protein partition coefficient depends on protein charge, gel-charge density, and solution ionic strength. Finally, a qualitative guide is presented for design of a polyelectrolyte gel such that it exhibits specified swelling and partitioning properties. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 87 TC 13 Z9 13 U1 2 U2 10 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0001-1541 J9 AICHE J JI AICHE J. PD AUG PY 1996 VL 42 IS 8 BP 2335 EP 2353 DI 10.1002/aic.690420823 PG 19 WC Engineering, Chemical SC Engineering GA VA864 UT WOS:A1996VA86400022 ER PT J AU Jankovic, JT Ihle, R Vick, DO AF Jankovic, JT Ihle, R Vick, DO TI Occupant generated carbon dioxide as a measure of dilution ventilation efficiency SO AMERICAN INDUSTRIAL HYGIENE ASSOCIATION JOURNAL LA English DT Article DE carbon dioxide decay; dilution ventilation efficiency; indoor air quality screening ID TRACER AB The lime rate of decay of occupant generated carbon dioxide after workers have left a work area can be used in indoor air quality screening. Tests in a dilution chamber proved the goodness-of-fit of a limited exponential decay model. Correlation coefficients for the log-linear plots of the chamber tests approached unity as did the ratios of actual airflow to calculated flow. The model was used to estimate the number of air changes per unit time at the point of sample collection. Multiplying the number of air changes per minute by the room volume gave the effective ventilation rate. Dividing the actual quantity of air entering the space by the effective quantity provided a measure of ventilation effectiveness, i.e., a measure of mixing. The number of room air changes measured by carbon dioxide decay was positively correlated with the evaluator's qualitative assessment of the ventilation effectiveness in several offices and laboratories. RP Jankovic, JT (reprint author), OAK RIDGE NATL LAB,OFF SAFETY & HLTH PROTECT,POB 2008,OAK RIDGE,TN 37831, USA. NR 8 TC 8 Z9 8 U1 0 U2 0 PU AMER INDUSTRIAL HYGIENE ASSOC PI FAIRFAX PA 2700 PROSPERITY AVE #250, FAIRFAX, VA 22031-4307 SN 0002-8894 J9 AM IND HYG ASSOC J JI Am. Ind. Hyg. Assoc. J. PD AUG PY 1996 VL 57 IS 8 BP 756 EP 759 DI 10.1202/0002-8894(1996)057<0756:OGCDAA>2.0.CO;2 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA VC305 UT WOS:A1996VC30500009 PM 8765206 ER PT J AU KsiezakReding, H Tracz, E Yang, LS Dickson, DW Simon, M Wall, JS AF KsiezakReding, H Tracz, E Yang, LS Dickson, DW Simon, M Wall, JS TI Ultrastructural instability of paired helical filaments from corticobasal degeneration as examined by scanning transmission electron microscopy SO AMERICAN JOURNAL OF PATHOLOGY LA English DT Article ID PROGRESSIVE SUPRANUCLEAR PALSY; MICROTUBULE-ASSOCIATED PROTEIN; ALZHEIMERS-DISEASE; NEUROFIBRILLARY TANGLES; TAU-PROTEINS; PICKS-DISEASE; HUMAN-BRAIN; ABNORMAL PHOSPHORYLATION; DIFFERENTIAL EXPRESSION; CYTOSKELETAL PATHOLOGY AB Paired helical filaments (PHFs) accumulate in the brains of subjects affected with Alzheimer's disease (AD) and certain other neurodegenerative disorders, including corticobasal degeneration (CBD). Electron microscope studies have shown that PHFs from CBD differ from those of AD by being wider and having a longer periodicity of the helical twist. Moreover, PHFs from CBD have been shown to be primarily composed of two rather than three highly phosphorylated polypeptides of tau (PHF-tau), with these polypeptides expressing no exons 3 and 10. To further explore the relationship between the heterogeneity of PHF-tau and the appearance of abnormal filaments, the ultrastructure and physical parameters such as mass per unit length and dimensions were compared in filaments from CBD and AD using high resolution scanning transmission electron microscopy (STEM). Filament-enriched fractions were isolated as Sarcosyl-insoluble pellets and for STEM studies, samples were freeze-dried without prior fixation or staining. Ultrastructurally, PHFs from CBD were shown to be a heterogeneous population as double- and single-stranded filaments could be identified based on their width and physical mass per unit length expressed in kilodaltons (kd) per nanometer (nm). Less abundant, double-stranded filaments had a maximal width of 29 win and a mass per unit length of 133 kd/nm, whereas three times more abundant single-stranded filaments were 15 nm wide and had a mass per unit length of 62 kd/nm. Double-stranded filaments also displayed a distinct axial region of less dense mass, which appeared to divide the PHFs into two protofilament-like strands. Furthermore, these filaments were frequently observed to physically separate along the long axis into two single strands or to break, longitudinally. In contrast, PHFs from AD were ultrastructurally stable and uniform both in their width (22 nm) and physical mass per unit length (104 kd/nm). The ultrastructural features indicate that filaments of CBD and AD differ both in stability and packing of tate and that CBD filaments, composed of two distinct protofilaments, are more labile under STEM conditions. As fixed and stained filaments from CBD have been shown to be stable and uniform in size by conventional transmission electron microscopy, STEM studies may be particularly suitable for detecting instability of unstained and unfixed filaments. The results also suggest that molecular heterogeneity and/or post-translational modifications of tau may strongly influence the morphology and stability of abnormal filaments. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RP KsiezakReding, H (reprint author), YESHIVA UNIV ALBERT EINSTEIN COLL MED,DEPT PATHOL,ROOM F-538,1300 MORRIS PK AVE,BRONX,NY 10461, USA. OI Dickson, Dennis W/0000-0001-7189-7917 FU NCRR NIH HHS [RR 01777]; NINDS NIH HHS [NS30027] NR 58 TC 37 Z9 38 U1 0 U2 0 PU AMER SOC INVESTIGATIVE PATHOLOGY, INC PI BALTIMORE PA 428 EAST PRESTON ST, BALTIMORE, MD 21202-3993 SN 0002-9440 J9 AM J PATHOL JI Am. J. Pathol. PD AUG PY 1996 VL 149 IS 2 BP 639 EP 651 PG 13 WC Pathology SC Pathology GA UZ763 UT WOS:A1996UZ76300028 PM 8702002 ER PT J AU Fearn, H James, DFV Milonni, PW AF Fearn, H James, DFV Milonni, PW TI Microscopic approach to reflection, transmission, and the Ewald-Oseen extinction theorem SO AMERICAN JOURNAL OF PHYSICS LA English DT Article AB We describe how the reflection and transmission of light at a dielectric interface can be understood starting from the fact that dielectrics are collections of molecules. More precisely, we consider from the microscopic perspective the interpretation and significance of the Ewald-Oseen extinction theorem of classical optics. The usual interpretation of the theorem is that an incident field is extinguished by the dipoles on the boundary and replaced by transmitted and reflected fields consistent with the Maxwell equations for the media. However, the extinction theorem is more appropriately regarded simply as a boundary condition effected by all the molecular scatterers, not just those at the boundary. To demonstrate this we take a microscopic approach to three familiar problems: (1) the electrostatic interaction of a point charge with a dielectric wall; (2) the reflection of a monochromatic plane wave at a dielectric interface; and (3) diffraction by an aperture. We show that the extinction of the incident field cannot be attributed to any finite dipole boundary layer, and in particular it does not involve any ''extinction theorem distance.'' (C) 1996 American Association of Physics Teachers. RP Fearn, H (reprint author), LOS ALAMOS NATL LAB,THEORET DIV T4,POB 1663,LOS ALAMOS,NM 87545, USA. RI James, Daniel/B-9805-2009 OI James, Daniel/0000-0003-3981-4602 NR 24 TC 21 Z9 21 U1 1 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD AUG PY 1996 VL 64 IS 8 BP 986 EP 995 DI 10.1119/1.18315 PG 10 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA VC882 UT WOS:A1996VC88200010 ER PT J AU Lipke, DL Aziz, SM Fagerland, JA Majesky, M Arcot, SS AF Lipke, DL Aziz, SM Fagerland, JA Majesky, M Arcot, SS TI Tenascin synthesis, deposition, and isoforms in monocrotaline-induced pulmonary hypertensive rat lungs SO AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY LA English DT Article DE cytotactin; hexabrachion; fibronectin; extracellular matrix ID EXTRACELLULAR-MATRIX PROTEIN; ALTERNATIVELY SPLICED FORMS; EXPRESSION; CYTOTACTIN; FIBRONECTIN; BINDING; MUSCLE; AORTA; CELLS; TISSUES AB Monocrotaline (MCT)-induced pulmonary hypertension is characterized by alterations in vascular extracellular matrix and neomuscularization of small blood vessels. Tenascin (TN) is a matrix glycoprotein which modulates cellular attachment, proliferation, and migration. The present study used immunohistochemistry and Northern analyses to examine the hypothesis that treatment of rats with the potent pneumotoxin MCT induces temporal alterations in TN synthesis/deposition in the affected lungs. MCT produced progressive pathological alterations in the cardiopulmonary system, including increased dry lung weight, right ventricular hypertrophy, and pulmonary hypertension by days 7, 14, and 21, respectively. TN positive foci were first observed in the parenchyma surrounding small muscularized pulmonary arteries in MCT-treated rats at day 4; these foci became both more pronounced and frequent as the disease progressed. TN was also observed in the media of the intrapulmonary artery at day 21. Northern analysis demonstrated increases in TN transcripts in MCT-treated rats as early as day 1. Furthermore, a unique transcript, apparently lacking some fibronectin type III-like units, was observed in mRNA extracted from these rats. These data demonstrate alterations in TN synthetic capacity and focal increases in TN deposition in lungs from MCT-treated rats and suggest that TN may be associated with the pathogenesis of pulmonary hypertension. C1 UNIV KENTUCKY, COLL PHARM, DIV PHARMACOL & EXPT THERAPEUT, LEXINGTON, KY 40536 USA. ABBOTT LABS, DEPT CELLULAR & MICROSCOP RES, ABBOTT PK, IL 60064 USA. BAYLOR COLL MED, DEPT PATHOL, HOUSTON, TX 77030 USA. LAWRENCE LIVERMORE NATL LAB, CTR HUMAN GENOME, LIVERMORE, CA 94551 USA. FU NHLBI NIH HHS [HL-36404, HL-02174, HL-43831] NR 33 TC 4 Z9 4 U1 0 U2 0 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 1040-0605 J9 AM J PHYSIOL-LUNG C JI Am. J. Physiol.-Lung Cell. Mol. Physiol. PD AUG PY 1996 VL 271 IS 2 BP L208 EP L215 PG 8 WC Physiology; Respiratory System SC Physiology; Respiratory System GA VD853 UT WOS:A1996VD85300004 PM 8770058 ER PT J AU VyasSomani, AC Aziz, SM Arcot, SA Gillespie, MN Olson, JW Lipke, DW AF VyasSomani, AC Aziz, SM Arcot, SA Gillespie, MN Olson, JW Lipke, DW TI Temporal alterations in basement membrane components in the pulmonary vasculature of the chronically hypoxic rat: Impact of hypoxia and recovery SO AMERICAN JOURNAL OF THE MEDICAL SCIENCES LA English DT Article DE fibronectin; laminin; type IV collagen; pulmonary hypertension ID MONOCROTALINE-TREATED RATS; SMOOTH-MUSCLE CELLS; HYPERTENSIVE RAT; RIGHT VENTRICLE; CAROTID-BODIES; HIGH-ALTITUDE; FIBRONECTIN; AORTA; EXPRESSION; LAMININ AB The hypoxic model of pulmonary hypertension was used to examine temporal alterations in the deposition of the basement membrane (BM) and components of fibronectin, laminin, and Type IV collagen within vascular, airway, and gas exchange compartments of the lung. Because hypoxic pulmonary hypertension is a reversible model of hypertension, changes in fibronectin and laminin synthesis/deposition in the recovering lung were also examined. Long-term hypoxic exposure produced decreases in body weight, increased right ventricular and lung dry weights and elevations in pulmonary arterial pressure. Immunohistochemical analysis revealed consistent and progressive increases in the deposition of fibronectin and laminin, but not type IV collagen, in the subendothelial and medial BMs of large and small pulmonary arteries, but not in airways or lung parenchyma. These changes were observed by day 4 of hypoxia and were most prominent in the conducting vasculature. Northern analysis showed a biphasic pattern of alterations in steady-state levels of BM component mRNA in hypoxic rats with early reductions at days 4 and 7 followed by increases at day 12. Recovery from 12 days of hypoxia resulted in regression of pulmonary hypertension and right ventricular hypertrophy but not increased lung weight. Immunohistochemical analysis of fibronectin, laminin, and type IV collagen levels in the vasculature showed a temporal regression to levels that were not remarkably different from time-matched controls at day 30 of recovery. Northern analysis of lungs from hypoxic-recovery rats revealed increased steady-state levels of mRNA for fibronectin, laminin, and type IV collagen at all time points. These data indicate that long-term hypoxic exposure elicits marked alterations in the synthetic capacity and deposition of the important cell attachment BM glycoproteins fibronectin and laminin. In addition, recovery from hypoxia appears to be characterized by a lack of increased fibronectin and laminin levels in the conducting vasculature, suggesting a marked and rapid reorganization of the vascular BMs on both hypoxic exposure and recovery from hypoxia. C1 UNIV KENTUCKY,COLL PHARM,DIV PHARMACOL & EXPT THERAPEUT,ALBERT B CHANDLER MED CTR,LEXINGTON,KY 40536. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA. FU NHLBI NIH HHS [HL36404, HL43831, HL02174] NR 46 TC 13 Z9 14 U1 0 U2 1 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0002-9629 J9 AM J MED SCI JI Am. J. Med. Sci. PD AUG PY 1996 VL 312 IS 2 BP 54 EP 67 DI 10.1097/00000441-199608000-00002 PG 14 WC Medicine, General & Internal SC General & Internal Medicine GA VB382 UT WOS:A1996VB38200002 PM 8701968 ER PT J AU Johnston, RO AF Johnston, RO TI Statistical artifacts in the ratio of discrete quantities - Reply SO AMERICAN STATISTICIAN LA English DT Letter RP Johnston, RO (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,POB 1663,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER STATIST ASSN PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0003-1305 J9 AM STAT JI Am. Stat. PD AUG PY 1996 VL 50 IS 3 BP 281 EP 281 PG 1 WC Statistics & Probability SC Mathematics GA VV331 UT WOS:A1996VV33100025 ER PT J AU Sutherland, JC Fisk, DJ Monteleone, DC Trunk, JG AF Sutherland, JC Fisk, DJ Monteleone, DC Trunk, JG TI A comparison of electrophoretic resolution for snapshot and finish-line imaging SO ANALYTICAL BIOCHEMISTRY LA English DT Article ID GEL-ELECTROPHORESIS; STRAND BREAKS; AGAROSE GELS; DNA LENGTH; FLUORESCENCE; QUANTITATION; FRAGMENTS; MOBILITY AB Finish-line imaging, in which DNA or other macromolecules are detected after electrophoresis for a constant distance, usually improves resolution compared to snapshot imaging, in which molecules are electrophoresed for a constant time in an apparatus of comparable dimensions. Resolving power, which is an objective measure of the ability of different separatory methods to detect closely spaced molecular species, can be used to compare directly the performance of systems employing both snapshot and finish-line imaging [E. A. Ribeiro and J. C. Sutherland, Anal. Biochem. 210, 378-388 (1993)]. Experimentally determined values of resolving power are influenced both by the method of imaging (snapshot vs finish-line) and by instrument-specific factors that affect resolution. Previous comparisons of the resolving power obtained with finish-line and snapshot imaging involved data sets acquired by different instruments with different instrumental resolutions. To reduce the influence of instrumental effects, we constructed a scanning laser fluorometer that can measure both snapshot and finish-line images of fluorochrome-labeled DNA. Snapshot and finish-line images of a DNA sample containing HaeII restriction fragments of the DNA from bacteriophage T7, which range in length from 474 to 6514 base pairs, were obtained under otherwise identical electrophoretic conditions. Snapshot and finish-line imaging give similar resolving powers for DNA molecules up to about 1.5 kbp long. For both imaging modes, maximum resolving power was achieved for DNA molecules between 2 and 3 kbp in length. For larger DNA molecules, finish-line imaging provided higher resolving power. The ratio of the resolving power of finish-line images to that of snapshot images increased monotonically as a function of DNA length. For the longest restriction fragments studied (6514 bp), the resolving power for finish-line images exceeded that of snapshot images by about 50%. (C) 1996 Academic Press, Inc. RP Sutherland, JC (reprint author), BROOKHAVEN NATL LAB, DEPT BIOL, UPTON, NY 11973 USA. NR 21 TC 3 Z9 3 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD AUG 1 PY 1996 VL 239 IS 2 BP 136 EP 144 DI 10.1006/abio.1996.0308 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VA593 UT WOS:A1996VA59300003 PM 8811892 ER PT J AU Tang, Q Harrata, AK Lee, CS AF Tang, Q Harrata, AK Lee, CS TI High-resolution capillary isoelectric focusing-electrospray ionization mass spectrometry for hemoglobin variants analysis SO ANALYTICAL CHEMISTRY LA English DT Article ID ELECTROPHORESIS; PROTEINS AB On-line capillary isoelectric focusing (CIEF)-electrospray ionization mass spectrometry (ESIMS) as a two-dimensional separation system is employed for high-resolution analysis of hemoglobin variants A, C, S, and F. The effects of moving ionic boundary inside the CIEF capillary and MS scan rate on the separation resolution and mass detection of hemoglobin variants are investigated. The formation of a moving ionic boundary due to the replacement of background electrolyte counterions with sheath liquid counterions can be minimized by combining cathodic mobilization with a gravity-induced hydrodynamic flow. Hemoglobin variants F and A, with a pf difference of 0.05 pH unit, are almost baseline resolved and identified in CIEF-ESIMS. The concentration detection limit for each hemoglobin variant is in the range of 10(-8) M, comparable to that obtained in two-dimensional gel electrophoresis using silver staining. initial preconcentration during the focusing step and the use of single-ion monitoring scan mode are responsible for improving detection limits. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. NR 9 TC 50 Z9 51 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1996 VL 68 IS 15 BP 2482 EP 2487 DI 10.1021/ac960169o PG 6 WC Chemistry, Analytical SC Chemistry GA VA003 UT WOS:A1996VA00300016 PM 21619194 ER PT J AU Tomkins, BA Griest, WH AF Tomkins, BA Griest, WH TI Determinations of N-nitrosodimethylamine at part-per-trillion concentrations in contaminated groundwaters and drinking waters featuring carbon-based membrane extraction disks SO ANALYTICAL CHEMISTRY LA English DT Article ID PESTICIDES; STABILITY AB A new solid-phase extraction procedure extracts N-nitrosodimethylamine (NDMA) at part-per-trillion (ng/L) concentrations from aqueous samples using a C-18 (reversed-phase) membrane extraction disk layered over a recently introduced carbon-based extraction disk, The reversed-phase disk removes nonpolar water-insoluble neutrals and is set aside; the carbon-based disk is extracted with a small volume of dichloromethane. NDMA is quantified in the organic extract using a gas chromatograph equipped with both a short-path thermal desorber and a chemiluminescent nitrogen detector, The detection limit for the procedure, calculated using two statistically unbiased protocols, is 3 ng of NDMA/L; the analyte recovery is similar to 57%. A related procedure substitutes a standard automatic sampler for the short-path thermal desorber and is suitable for determining NDMA in heavily contaminated (> 300 ng of NDMA/L) aqueous samples, The detection limit for the procedure, calculated in the same manner as above, is 300 ng of NDMA/L, with an analyte recovery of similar to 64%. The detection limits and measured recovery values are comparable to those observed in earlier work, in which a conventional continuous overnight extraction with dichloromethane was used to remove NDMA from the aqueous samples. The newer procedures described herein offer a 50-fold savings in extraction time and a 100-fold reduction in dichloromethane consumed per sample while maintaining the wide range (3-4 orders of magnitude concentrations of NDMA) observed for the original procedures used in tandem, Authentic contaminated groundwaters are extracted using both the conventional and disk-based extraction procedures and analyzed; the observed NDMA concentrations are virtually identical over a target range spanning 100-10000 ng of NDMA/L. RP Tomkins, BA (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,ORGAN CHEM SCIT,POB 2008,OAK RIDGE,TN 37831, USA. OI Tomkins, Bruce/0000-0001-8520-1415 NR 20 TC 35 Z9 40 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1996 VL 68 IS 15 BP 2533 EP 2540 DI 10.1021/ac9601573 PG 8 WC Chemistry, Analytical SC Chemistry GA VA003 UT WOS:A1996VA00300022 PM 8694259 ER PT J AU Jankowiak, R Zamzow, D Ding, W Small, GJ AF Jankowiak, R Zamzow, D Ding, W Small, GJ TI Capillary electrophoresis-fluorescence line-narrowing system for on-line structural characterization of molecular analytes SO ANALYTICAL CHEMISTRY LA English DT Article ID BENZOPYRENE DNA-ADDUCTS; ELECTROKINETIC CHROMATOGRAPHY; GEL-ELECTROPHORESIS; MOUSE SKIN; IDENTIFICATION; SPECTROMETRY; QUANTITATION; SPECTROSCOPY; ERYTHROCYTE; SEPARATIONS AB We have demonstrated, for the first time, that capillary electrophoresis (CE) can be interfaced with low-temperature fluorescence line-narrowing (FLN) spectroscopy for on-line structural characterization. Detection by laser-induced fluorescence spectroscopy, under fluorescence non-line-narrowing and Line-narrowing conditions, provides three-dimensional electropherograms and FLN spectra, which lead to significantly improved overall resolution and allow for structural characterization (''fingerprinting'') of molecular analytes. This novel CE-FLN system consists of a modular CE system, instrumentation for FLN spectroscopy, and a specially designed capillary cryostat (CC). An absorbance detector serves to determine the migration rates of analytes. After the 77 K fluorescence-based electropherogram is generated, the temperature of the capillary is lowered to 4.2 K for high-resolution FLN characterization. Automated translation of the CG and capillary in the direction of the capillary axis allows the separated analytes to be sequentially characterized by fluorescence spectroscopy as the capillary is translated through the laser excitation region. Detection of fluorescence from stationary CE-separated analytes significantly improves the accuracy of quantitation and structural characterization. We believe that this interfacing represents an exciting addition to the rapidly evolving field of CE, providing a new and powerful tool for chemical analysis. The first application of the CE-FLN system to a mixture of polycyclic aromatic hydrocarbons is presented; prospects and future applications of CE-FLN are briefly addressed. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 41 TC 27 Z9 27 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1996 VL 68 IS 15 BP 2549 EP 2553 DI 10.1021/ac960251j PG 5 WC Chemistry, Analytical SC Chemistry GA VA003 UT WOS:A1996VA00300024 PM 21619200 ER PT J AU Fowler, JS Fazzini, E Volkow, ND AF Fowler, JS Fazzini, E Volkow, ND TI Deprenyl and levodopa and Parkinson's disease progression SO ANNALS OF NEUROLOGY LA English DT Letter ID BRAIN C1 NYU,NEW YORK,NY 10029. RP Fowler, JS (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 3 TC 5 Z9 5 U1 0 U2 0 PU LITTLE BROWN CO PI BOSTON PA 34 BEACON STREET, BOSTON, MA 02108-1493 SN 0364-5134 J9 ANN NEUROL JI Ann. Neurol. PD AUG PY 1996 VL 40 IS 2 BP 267 EP 268 DI 10.1002/ana.410400228 PG 2 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA VC689 UT WOS:A1996VC68900027 PM 8773616 ER PT J AU Deka, C Steinkamp, JA AF Deka, C Steinkamp, JA TI Time-resolved fluorescence-decay measurement and analysis on single cells by flow cytometry SO APPLIED OPTICS LA English DT Article ID LIFETIME MEASUREMENTS; LEAST-SQUARES; KINETICS; DNA; DYE AB A novel method is described for the measurement and analysis of fluorescence decays of individual cells and particles in flow. It combines the rapid measurement capabilities of a flow cytometer and the robust measurement and analysis procedures of time-domain fluorescence-lifetime spectroscopy. For excitation we use a cw laser that is pulse modulated by an electro-optic modulator. The characteristics and the repetition rate of the excitation pulses can be easily adjusted to accommodate fluorescence decays with a wide range of lifetimes. (C) 1996 Optical Society of America C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NR 26 TC 12 Z9 12 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD AUG 1 PY 1996 VL 35 IS 22 BP 4481 EP 4489 DI 10.1364/AO.35.004481 PG 9 WC Optics SC Optics GA VA289 UT WOS:A1996VA28900023 PM 21102863 ER PT J AU Li, YL Pretzler, G Fill, EE Nilsen, J AF Li, YL Pretzler, G Fill, EE Nilsen, J TI Study of anomalous lasing behavior on the two J=0-1 transitions in Ne-like V SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID X-RAY LASERS; PREPULSE TECHNIQUE; ZINC; NM AB We present an experimental report on the recent observation of lasing at 26.1 and 30.4 nm on the 3p(1)S(0)-3s(3)P(1), [termed G(0-1)] and 3p(1)S(0)-3s(1)P(1) [termed E(0-1)] transitions in Ne-like V, in which the normally weak G(0-1) transition was observed to lase more strongly than the E(0-1) transition. The experiment was performed on the Asterix IV iodine laser with a prepulse 5.23 ns before the main pulse. At a target length of about 2.5 cm, it was found that, while the G(0-1) and E(0-1) lines have comparable intensities in V, the E(0-1) line dominates spectra from Mn, Cr, Ti and Sc, which have adjacent nuclear charges. It was also found that the two lasers in V also have different temporal histories and spatial distributions. This is in contrast to the LASNEX + XRASER simulation, which predicts virtually similar temporal and spatial behavior for the two transitions. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Li, YL (reprint author), MAX PLANCK INST QUANTUM OPT,HANS KOPFERMANN STR 1,D-85748 GARCHING,GERMANY. NR 24 TC 6 Z9 6 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD AUG PY 1996 VL 63 IS 2 BP 125 EP 130 DI 10.1007/BF01095261 PG 6 WC Optics; Physics, Applied SC Optics; Physics GA VA196 UT WOS:A1996VA19600006 ER PT J AU Mincher, BJ Liekhus, K Arbon, RE AF Mincher, BJ Liekhus, K Arbon, RE TI PCB radiolysis in isooctane in the presence of ozone SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID POLYCHLORINATED-BIPHENYLS; HYDROXYL RADICALS; DECHLORINATION; 2-PROPANOL AB In a single set of experiments we have investigated the effect of ozone on the radiation chemistry of PCB 155 in isooctane. The results suggest that PCB decomposition in this oil-like alkane solution is inhibited by ozone, probably due to the ozone-electron capture reaction. Hydroxyl radicals generated by ozone-electron capture apparently do not play a role in PCB decomposition in this matrix. Copyright (C) 1996 Elsevier Science Ltd RP Mincher, BJ (reprint author), IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. RI Mincher, Bruce/C-7758-2017 NR 9 TC 7 Z9 13 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD AUG PY 1996 VL 47 IS 8 BP 713 EP 715 DI 10.1016/0969-8043(96)00060-7 PG 3 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VH992 UT WOS:A1996VH99200001 ER PT J AU Scarpitta, SC Fisenne, IM AF Scarpitta, SC Fisenne, IM TI Cerenkov counting as a complement to liquid scintillation counting SO APPLIED RADIATION AND ISOTOPES LA English DT Article AB A commercially available spectrometer was calibrated for liquid scintillation (LS) and Cerenkov counting efficiency (CCE) using National Institute of Standards and Technology traceable solutions. The CCE increased linearly over a 3 order of magnitude range in K-40 beta activity, and by 42% per MeV as beta-energies increased from 0.300 to 3.54 MeV, achieving a maximum value of 80% for Ru-106/Rh-106. The CCE can be enhanced by 10-15% when a wavelength shifter is used. A comparison of the data showed that the CCE was typically 20-50% less than the LS counting efficiency for beta-particles with maximum energies >1 MeV. Applications that utilize sequential CCE and LS counting to quantitate activity concentrations are discussed for samples containing two beta-emitting nuclides of differing energies. Published by Elsevier Science Ltd RP Scarpitta, SC (reprint author), US DOE,ENVIRONM MEASUREMENTS LAB,NEW YORK,NY 10014, USA. NR 22 TC 3 Z9 3 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD AUG PY 1996 VL 47 IS 8 BP 795 EP 800 DI 10.1016/0969-8043(96)00061-9 PG 6 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VH992 UT WOS:A1996VH99200016 ER PT J AU Duan, YX Li, YM Du, ZH Jin, QH Olivares, JA AF Duan, YX Li, YM Du, ZH Jin, QH Olivares, JA TI Instrumentation and fundamental studies on glow discharge-microwave-induced plasma (GD-MIP) tandem source for optical emission spectrometry SO APPLIED SPECTROSCOPY LA English DT Article DE tandem source; glow discharge; microwave plasma; optical emission spectrometry; instrumentation; fundamental study ID ATOMIC-EMISSION; EXCITATION TEMPERATURES; ATMOSPHERIC-PRESSURE; LAMP; HELIUM; TORCH; SURFATRON; DENSITIES; METALS; ARGON AB Instrumentation and fundamental studies on glow discharge-microwave-induced plasma (GD-MIP) tandem source are described in this paper. Mutual effects among parameters, vacuum pressure, discharge current, voltage, and microwave power are examined with different cathode materials. Sputtering rates with and without microwave boost are measured under various experimental conditions. The experimental results demonstrate that the introduction of a microwave plasma will significantly decrease the sampling rate. A possible mechanism for the more uniform erosion obtained with microwave plasma boosting is suggested and discussed. Excitation temperatures are measured with the line-pair method and Boltzmann plot. A considerable increase in the excitation temperature (from about 3500 to 4200 K by using the line-pair method) is found with the addition of microwave plasma boosting. A comparison of the behavior of glow discharge alone and the GD-MIP tandem source is made. Significant enhancements in signal intensities are observed. The experimental results suggest that the excitation temperature plays an important role in signal enhancement. C1 JILIN UNIV,DEPT CHEM,CHANGCHUN 130023,PEOPLES R CHINA. RP Duan, YX (reprint author), LOS ALAMOS NATL LAB,CST-9,MS J514,LOS ALAMOS,NM 87545, USA. NR 37 TC 6 Z9 7 U1 1 U2 1 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD AUG PY 1996 VL 50 IS 8 BP 977 EP 984 DI 10.1366/0003702963905259 PG 8 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA VD855 UT WOS:A1996VD85500006 ER PT J AU AlKhanbashi, A Hansen, MG Wachter, EA AF AlKhanbashi, A Hansen, MG Wachter, EA TI Improved fiber-optic method for monitoring emulsion composition using Raman scattering SO APPLIED SPECTROSCOPY LA English DT Article DE emulsion polymerization; Raman scattering; process monitoring; epi-illumination; optical fibers; fiber-optic probe ID SPECTROSCOPY; PROBE; POLYMERIZATION C1 UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN 37831. NR 19 TC 10 Z9 10 U1 0 U2 0 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD AUG PY 1996 VL 50 IS 8 BP 1089 EP 1092 DI 10.1366/0003702963905268 PG 4 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA VD855 UT WOS:A1996VD85500022 ER PT J AU Zunger, A Wang, LW AF Zunger, A Wang, LW TI Theory of silicon nanostructures SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium on Si Heterostructures - From Physics to Devices CY SEP 11-14, 1995 CL IRAKLION, GREECE ID POROUS SILICON; QUANTUM CONFINEMENT; SEMICONDUCTOR CLUSTERS; ELECTRONIC-STRUCTURE; OPTICAL-PROPERTIES; SIZE DEPENDENCE; BAND-GAP; DOTS; PHOTOLUMINESCENCE; NANOCRYSTALLITES AB Empirical pseudopotential plane wave theory is used to study the electronic and optical properties of thousand atom hydrogen passivated Si quantum dots, wires and films. The properties studied include: (1) band gap vs. size; (2) band gap vs. shape; (3) total electronic density of state and optical absorption spectra: (4) dielectric constant vs. size. The results are compared with tight binding and other model calculations. Comparison with recent experimental data is discussed. RP Zunger, A (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 33 TC 113 Z9 115 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1996 VL 102 BP 350 EP 359 DI 10.1016/0169-4332(96)00078-5 PG 10 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA VJ861 UT WOS:A1996VJ86100073 ER PT J AU Pickens, RM Jagoe, CH AF Pickens, RM Jagoe, CH TI Relationships between precipitation and surface water chemistry in three Carolina Bays SO ARCHIV FUR HYDROBIOLOGIE LA English DT Article ID DECLINING AMPHIBIAN POPULATIONS; TOTAL ORGANIC-CARBON; ULTRAVIOLET ABSORBANCE; HYDROLOGY AB Samples of surface water and bulk precipitation were collected bi-weekly for more than 2 1/2 years at three Carolina bays along a 25 km transect located on the Savannah River Site, South Carolina, U.S.A. Carolina bays are freshwater wetlands, the most abundant lentic systems of natural origin on the southeastern US coastal plain. Precipitation chemistry was similar at all sites; mean pH was 4.56, and the major ions were H+, 34.7% of total cations, and SO4--, 47.1% of total anions. H+ was positively correlated with SO4-- in precipitation, implying anthropogenic acids influence precipitation chemistry in this region. All three bays, Rainbow Bay (RE), Thunder Bay (TB), and Ellenton Bay (EB), contained soft (specific conductivity 5-90 mu S/cm), acidic water (pH 4.0-5.9) with dissolved organic matter (DOM) from 4-60 mg/L. The major cations for RE, TB, and EB, respectively, were: Mg++ (31.6% of total); Na+ (26% of total); and Ca++(30.8% of total). DOM was the major anion for all bays, and SO4-- represented 14 to 28% of all anions. H+ was not correlated with DOM or SO4-- in any of the three bays. In each bay, ionic concentrations varied over time. SO4-- concentrations were significantly higher in Rainbow Bay than Thunder Bay or Ellenton Bay, and H+ concentrations were significantly higher in Thunder Bay than in the other two bays. This suggests that different biogeochemical processes may influence pH and other chemical variables in each bay. Precipitation and shallow groundwater are dominant water sources for these bays, but for all three bays changes in surface water H+ were not directly correlated with precipitation loading of H+, NO3-, or SO4--. However, ratios of SO4--: Cl- in all three bays and in precipitation were higher than would be expected if marine aerosols were the major SO4-- source, suggesting that atmospheric inputs of anthropogenic acids may influence bay chemistry. RP Pickens, RM (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,PO DRAWER E,AIKEN,SC 29802, USA. NR 36 TC 5 Z9 6 U1 0 U2 3 PU E SCHWEIZERBART'SCHE VERLAGS PI STUTTGART PA NAEGELE U OBERMILLER JOHANNESSTRASSE 3A, D 70176 STUTTGART, GERMANY SN 0003-9136 J9 ARCH HYDROBIOL JI Arch. Hydrobiol. PD AUG PY 1996 VL 137 IS 2 BP 187 EP 209 PG 23 WC Limnology; Marine & Freshwater Biology SC Marine & Freshwater Biology GA VE914 UT WOS:A1996VE91400004 ER PT J AU Napolitano, GE Shantha, NC Hill, WR Luttrell, AE AF Napolitano, GE Shantha, NC Hill, WR Luttrell, AE TI Lipid and fatty acid compositions of stream periphyton and Stoneroller Minnows (Campostoma anomalum): Trophic and environmental implications SO ARCHIV FUR HYDROBIOLOGIE LA English DT Article ID WATER; ALGAE; FISH; PHYTOPLANKTON; TEMPERATURE; PESTICIDES; CULTURE AB Lipids and fatty acids were analyzed in the herbivorous minnow (Campostoma anomalum) and its predominant food (periphyton) in three streams in eastern Tennessee (East Fork Poplar Creek, Hinds Creek and White Oak Creek). Fatty acid markers were used to explore the trophic relationship between the fish and its algal food. C. anomalum are lipid-rich fish, with a high potential for uptake of hydrophobic pollutants. The mean lipid content of the minnows was 6.5 % of the wet weight in the carcasses, and 26.5 % of the digestive tract. The concentrations of polychlorinated biphenyls (PCBs) in the fish carcasses and guts were directly proportional to the lipid contents of these body portions. Microscopic examination of periphyton in the guts, and the analysis of fatty acid markers showed that green algae dominated periphyton ingested by the minnows in East Fork Poplar Creek (similar to 90 % of the ingested algal biomass was from chlorophytes). The fatty acid profiles of the minnow guts (including their gut contents), and their lipid stores in East Fork Poplar Creek also reflected extensive ingestion of green algae indicated by an abundance of a fatty acid marker a-linolenic acid (18:3 omega 3), at 13 % of the total fatty acids. A relatively low biomass of diatoms, and a correspondingly low concentration of a fatty acid characteristic of diatoms (eicosapentaenoic acid, 20:5 omega 3) occurred in periphyton from both Hinds Creek and White Oak Creek. Nevertheless, taxonomic and lipid analyses of the minnow gut contents showed that in White Oak Creek diatoms constituted a disproportionately large share of the minnows' diet. The discrepancy in fatty acid profiles between the portion of periphyton in this stream and the gut contents of C. anomalum suggests that the minnows do not consume all portions of the periphyton equally. These results emphasize the applicability of fatty acid analysis to reveal trophic linkages in aquatic ecosystems. C1 UNIV KENTUCKY, FOOD SCI SECT, DEPT ANIM SCI, LEXINGTON, KY 40545 USA. UNIV VIRGINIA, DEPT BIOL, CHARLOTTESVILLE, VA 22903 USA. RP Napolitano, GE (reprint author), OAK RIDGE NATL LAB, DIV ENVIRONM SCI, POB 2008, OAK RIDGE, TN 37831 USA. RI Chandrasekaran, Shantha/A-7515-2011 NR 35 TC 14 Z9 14 U1 4 U2 21 PU E SCHWEIZERBARTSCHE VERLAGSBUCHHANDLUNG PI STUTTGART PA NAEGELE U OBERMILLER, SCIENCE PUBLISHERS, JOHANNESSTRASSE 3A, D 70176 STUTTGART, GERMANY SN 0003-9136 J9 ARCH HYDROBIOL JI Arch. Hydrobiol. PD AUG PY 1996 VL 137 IS 2 BP 211 EP 225 PG 15 WC Limnology; Marine & Freshwater Biology SC Marine & Freshwater Biology GA VE914 UT WOS:A1996VE91400005 ER PT J AU Hayashi, K Thabit, G Bogdanske, JJ Mascio, LN Markel, MD AF Hayashi, K Thabit, G Bogdanske, JJ Mascio, LN Markel, MD TI The effect of nonablative laser energy on the ultrastructure of joint capsular collagen SO ARTHROSCOPY LA English DT Article DE joint capsule; laser; collagen; electron microscopy; ultrastructure ID SHOULDER INSTABILITY; FIBRIL FORMATION; INVITRO; YAG AB This study was designed to evaluate the effect of laser energy at nonablative levels on the ultrastructure of joint capsular collagen. The femoropatellar joint capsules of six mature New Zealand white rabbits were harvested immediately after death. Specimens were divided into three treatment groups (5, 10, and 15 watts) and one control group. Laser energy was applied using a holmium:YAG laser. Transmission electron microscopy showed significant ultrastructural alterations in collagenous architecture for all laser treatment groups, with increased fibril cross-sectional diameter for each of the treated groups, The fibrils began to lose their distinct edges and their periodical cross-striations at subsequently higher energy densities. A morphometric analysis showed that each subsequently higher laser energy caused a significant increase in collagen fibril diameter. Ultrastructural alteration of collagen fibril architecture caused by the thermal effect of laser energy is probably the dominant mechanism of laser-induced tissue shrinkage. C1 UNIV WISCONSIN,SCH VET MED,DEPT SURG SCI,COMPARAT ORTHOPAED RES LAB,MADISON,WI 53706. SPORTS ORTHOPED & REHABIL MED ASSOCIATES,MENLO PK,CA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. FU NCRR NIH HHS [RR 001192] NR 40 TC 105 Z9 112 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0749-8063 J9 ARTHROSCOPY JI Arthroscopy PD AUG PY 1996 VL 12 IS 4 BP 474 EP 481 DI 10.1016/S0749-8063(96)90043-2 PG 8 WC Orthopedics; Surgery SC Orthopedics; Surgery GA VC876 UT WOS:A1996VC87600013 PM 8864007 ER PT J AU Gregg, MD Becker, RH White, RL Helfand, DJ McMahon, RG Hook, IM AF Gregg, MD Becker, RH White, RL Helfand, DJ McMahon, RG Hook, IM TI The first bright QSO survey SO ASTRONOMICAL JOURNAL LA English DT Article ID QUASARS AB The FIRST radio survey provides a new resource for constructing a large quasar sample, With source positions accurate to better than 1 '' and a point source sensitivity limit of 1 mJy, it reaches 50 times deeper than previous radio catalogs, We report here on the results of the pilot phase for a FIRST Bright Quasar Survey (FBQS), Based on matching the radio catalog from the initial 300 deg(2) of FIRST coverage with the optical catalog from the Automated Plate Machine (APM) digitization of Palomar Sky Survey plates, we have defined a sample of 219 quasar candidates brighter than E = 17.50, We have obtained optical spectroscopy for 151 of these and classified 25 others from the literature, yielding 69 quasars or Seyfert 1 galaxies, of which 51 are new identifications. The brightest new quasar has an E magnitude of 14.6 and z = 0.91; four others are brighter than E = 16, The redshifts range from z = 0.12 to 3.42. Half of the detected objects are radio quiet with L(21-cm) < 10(32.5) ergs/s. We use the results of this pilot survey to establish criteria for the FBQS that will produce a quasar search program which will be 70% efficient and 95% complete to a 21-cm flux density limit of 1.0 mJy. (C) 1996 American Astronomical Society. C1 UNIV CALIF DAVIS, DAVIS, CA 95616 USA. SPACE TELESCOPE SCI INST, BALTIMORE, MD 21218 USA. COLUMBIA UNIV, COLUMBIA ASTROPHYS LAB, NEW YORK, NY 10027 USA. UNIV CAMBRIDGE, INST ASTRON, CAMBRIDGE CB3 0HA, ENGLAND. UNIV CALIF BERKELEY, BERKELEY, CA 94720 USA. RP Gregg, MD (reprint author), LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. OI McMahon, Richard/0000-0001-8447-8869 NR 11 TC 100 Z9 102 U1 0 U2 0 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 AUG PY 1996 VL 112 IS 2 BP 407 EP 415 DI 10.1086/118024 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ553 UT WOS:A1996UZ55300007 ER PT J AU Minniti, D Meylan, G KisslerPatig, M AF Minniti, D Meylan, G KisslerPatig, M TI Globular cluster halos around dwarf elliptical galaxies SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies, individual, the Fornax dSph, NGC 185, NGC 147, NGC 205; galaxies, star clusters; globular clusters, individual, Ter 7 ID LOCAL GROUP; SPHEROIDAL GALAXY; M31; PHOTOMETRY; SYSTEMS; SEARCH; METALLICITIES; SAGITTARIUS; ABUNDANCES; NGC-185 AB Dwarf galaxies are thought to be one of the building elements of spiral galaxies like the Milky Way, adding their globular clusters (GCs) to the halo when they merge. However, nearby dwarf elliptical galaxies have few or no GCs, complicating the study of their contribution in the context of halo formation. In order to improve on the statistics, we have constructed a master-dE galaxy by combining the data from several well studied dEs in the Local Group, scaling the projected distances in units of core radius. Using this master dE, we address the following basic questions: Are there halos of GCs around dEs? If so, are they flattened in a way similar to the host galaxies or are they more spherical? The answers to the above questions might give some clues about the formation of galaxies. We also examine the metallicity distribution of the GC system of this master dE galaxy. Using this information, we argue that the metal-rich globular cluster Ter 7 is unlikely to be a member of the recently discovered Sgr dwarf galaxy. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Minniti, D (reprint author), EUROPEAN SO OBSERV, KARL SCHWARZSCHILD STR 2, D-85748 GARCHING, GERMANY. NR 54 TC 21 Z9 21 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 AUG PY 1996 VL 312 IS 1 BP 49 EP 54 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VC218 UT WOS:A1996VC21800011 ER PT J AU Gandhi, R Quigg, C Reno, MH Sarcevic, I AF Gandhi, R Quigg, C Reno, MH Sarcevic, I TI Ultrahigh-energy neutrino interactions SO ASTROPARTICLE PHYSICS LA English DT Review DE neutrino astronomy; neutrino-nucleon scattering; neutrino-electron scattering ID INELASTIC EP-SCATTERING; COSMIC-RAY NEUTRINOS; PARTON DISTRIBUTIONS; ATMOSPHERIC NEUTRINOS; SOLAR NEUTRINOS; GALACTIC NUCLEI; CROSS-SECTIONS; AIR SHOWERS; TOP-QUARK; SMALL-X AB Cross sections for the interactions of ultrahigh-energy neutrinos with nucleons are evaluated in the light of new information about nucleon structure functions, For 10(20) eV neutrinos, the cross section is about 2.4 times previous estimates, We also review the cross sections for neutrino interactions with atomic electrons, Some consequences for interaction rates in the Earth and for event rates from generic astrophysical sources in large-scale detectors are noted. C1 FERMILAB NATL ACCELERATOR LAB, DEPT THEORET PHYS, BATAVIA, IL 60510 USA. CORNELL UNIV, FLOYD R NEWMAN LAB NUCL STUDIES, ITHACA, NY 14853 USA. UNIV IOWA, DEPT PHYS & ASTRON, IOWA CITY, IA 52242 USA. UNIV ARIZONA, DEPT PHYS, TUCSON, AZ 85721 USA. RP MEHTA RES INST, 10 KASTURBA GANDHI MARG, ALLAHABAD 211002, UTTAR PRADESH, INDIA. OI Reno, Mary Hall/0000-0001-6264-3990 NR 162 TC 371 Z9 373 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 EI 1873-2852 J9 ASTROPART PHYS JI Astropart Phys. PD AUG PY 1996 VL 5 IS 2 BP 81 EP 110 DI 10.1016/0927-6505(96)00008-4 PG 30 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VE116 UT WOS:A1996VE11600001 ER PT J AU Brainerd, TG Blandford, RD Smail, I AF Brainerd, TG Blandford, RD Smail, I TI Weak gravitational lensing by galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, fundamental parameters; galaxies, halos; gravitational lensing ID IMAGE DISTORTION; EVOLUTION; SCALE; HALOS; MASS AB We report a detection of weak, tangential distortion of the images of cosmologically distant, faint galaxies due to gravitational lensing by foreground galaxies. A mean image polarization of (p) = 0.011 +/- 0.006 (95% confidence bounds) is obtained for 3202 pairs of source (23 < r(s) less than or equal to 24) and lens (20 (20 less than or equal to r(d) less than or equal to 23) galaxies with projected separations of 5 '' less than or equal to theta 34 ''. Averaged over annuli of inner radius 5 '' and outer radius theta(max), the signal is string for lens-source separations of theta(max) less than or similar to 90 '' consistent with quasi-isothermal galaxy halos extending to large radii (greater than or similar to 100 h(-1) kpc). The observed polarization is also consistent with the signal expected on the basis of simulations incorporating measured properties of local galaxies and modest extrapolations of the observed redshift distribution of faint galaxies (to which the results are somewhat sensitive). From the simulations we obtain formal best-fit model parameters for the dark halos of the lens galaxies that consist of a characteristic circular velocity of V* similar to 220 +/- 80 km s(-1) and characteristic radial extent of s* greater than or similar to 100 h(-1) kpc. The predicted polarization based on the model is relatively insensitive to the characteristic radial extent of the halos, s*, and very small halos (s* similar to 10 h(-1) kpc) are excluded only at the 2 sigma level. The formal best-fit halo parameters imply typical masses for the lens galaxies within a radius of 100 h(-1) kpc on the order of 1.0(-0.5)(+1.2) x 10(12) h(-1) M. (90% confidence bounds), in agreement with recent dynamical estimates of the masses of local spiral galaxies. This is particularly encouraging as the lensing and dynamical mass estimators rely on different sets of assumptions. Contamination of the gravitational lensing signal by a population of tidally distorted satellite galaxies can be ruled out with reasonable confidence. The prospects for corroborating and improving this measurement seem good, especially using deep HST archival data. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. CALTECH,PASADENA,CA 91125. OBSERV CARNEGIE INST WASHINGTON,PASADENA,CA 91101. RI Smail, Ian/M-5161-2013; Brainerd, Tereasa /H-4479-2014 OI Smail, Ian/0000-0003-3037-257X; NR 29 TC 284 Z9 284 U1 2 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1996 VL 466 IS 2 BP 623 EP 637 DI 10.1086/177537 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ546 UT WOS:A1996UZ54600003 ER PT J AU Long, KS Charles, PA Blair, WP Gordon, SM AF Long, KS Charles, PA Blair, WP Gordon, SM TI A deep X-ray image of M33 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, individual (M33); supernova remnants; X-rays, galaxies; X-rays, ISM ID SUPERNOVA-REMNANTS; MORPHOLOGY; EMISSION; GALAXY AB A 50.4 ks ROSAT Position Sensitive Proportional Counter image of the nearby spiral galaxy M33 reveals 37 sources within 15' of the nucleus brighter than 7 x 10(35) ergs s(-1). There are at least 13 additional sources farther from the nucleus, most of which are likely to be associated with M33 as well. Most of the bright sources that had been detected with Einstein in the same region are still visible. The bulk of the sources in the galaxy are associated with Population I tracers. Several of the sources are time variable. There are 10 sources in the image that lie within 20 '' of optically identified supernova remnants (SNRs) in M33. The spectra of these sources are soft compared with most other sources of comparable brightness, and therefore it is likely that most of these X-ray sources are SNRs. Based on the identification of sources in M33, it appears likely that ROSAT hardness ratios of this type can be used to separate SNRs and compact sources in other nearby normal galaxies as well. The northern and the southern spiral arms of M33 appear as diffuse features in the X-ray image. There is additional diffuse (or unresolved source) emission throughout the inner portions of M33. The diffuse emission is softer than the faint point sources and the SNRs in the survey, and is well fitted in terms of a bremsstrahlung spectrum with kT similar to 0.4 keV and log N-H similar to 20.6. C1 UNIV OXFORD,DEPT ASTROPHYS,OXFORD OX1 3RH,ENGLAND. JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Long, KS (reprint author), SPACE TELESCOPE SCI INST,3700 SAN MARTIN DR,BALTIMORE,MD 21218, USA. NR 26 TC 46 Z9 46 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1996 VL 466 IS 2 BP 750 EP & DI 10.1086/177548 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ546 UT WOS:A1996UZ54600014 ER PT J AU Link, B Epstein, RI AF Link, B Epstein, RI TI Statistics of gamma-ray burst temporal asymmetry SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays, bursts; methods, statistical AB We study the temporal asymmetry of over 600 bursts from the BATSE 3B catalog, encompassing a 200-fold range in peak flux. By comparing the rates of rise and fall of the flux near the highest peak of each burst, we find that about two-thirds of the bursts exhibit a preferred asymmetry in the sense that the flux rises more rapidly than it falls, confirming the conclusions of previous studies employing smaller databases. The probability that the observed time asymmetry is a statistical fluctuation is less than 10(-5); therefore, models that predict time symmetry of the burst profile are ruled out. We find no statistically significant correlation between burst temporal asymmetry and peak flux. This result is consistent with both cosmological and local interpretations of the gamma-ray burst phenomenon. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Link, B (reprint author), MONTANA STATE UNIV,DEPT PHYS,BOZEMAN,MT 59717, USA. NR 15 TC 10 Z9 10 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1996 VL 466 IS 2 BP 764 EP 767 DI 10.1086/177550 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ546 UT WOS:A1996UZ54600016 ER PT J AU Eastman, RG Schmidt, BP Kirshner, R AF Eastman, RG Schmidt, BP Kirshner, R TI The atmospheres of Type II supernovae and the expanding photosphere method SO ASTROPHYSICAL JOURNAL LA English DT Article DE radiative transfer; stars, atmospheres; stars, distances; supernovae, general ID EXTRAGALACTIC DISTANCE SCALE; LOW-DENSITY PHOTOSPHERES; SPHERICALLY SYMMETRIC FLOWS; LARGE MAGELLANIC CLOUD; LIGHT CURVES; SPECTRAL FLUX; CEPHEID VARIABLES; HUBBLE CONSTANT; MASSIVE STARS; SN-1993J AB The Expanding Photosphere Method (EPM) determines distances to Type II supernova (SNe II) by comparing the photospheric angular size with the expansion velocity measured from spectral lines. The photospheres of SNe II are low density and are dominated by electron scattering, and consequently the photospheric flux is dilute relative to a Planck function at the best-fitting continuum color temperature The reliability of EPM distances depends on understanding how the dilution is related to physical properties of the supernova atmosphere. To study this, we have calculated 63 different model atmospheres relevant to SNe II. The excitation, ionization, and thermal structure are described for the case of high effective temperature in which the atmosphere is completely ionized, and for the case of cooler effective temperatures in which the photosphere is formed in a region of recombining hydrogen. The general spectral features of both cases are discussed. We explore how the computed spectrum changes with density structure, helium abundance, metallicity, expansion rate, and luminosity or effective temperature. The most important variable in determining spectral appearance is the effective temperature. The amount by which the emergent flux is dilute relative to the best-fitting blackbody depends on a number of factors, most important of which are the temperature and, in short-wavelength bandpasses, density at the photosphere. For each of the models we derive distance correction factors for application in EPM, using the four filter combinations {BV}, {VIc}, {BVIc}, and {JHK}. The main differences may be expressed in terms of the observable color temperature and a slowly varying dependence on density. Functional fits to the distance correction factor are provided which can be used to estimate the photospheric angular size from broadband photometry. The effect of uncertain dust extinction on angular size is shown to be small. This work places EPM on a firm theoretical foundation and substantiates the Hubble constant measurement by Schmidt et al. of H-0 = 73 +/- 7. C1 AUSTRALIAN NATL UNIV, MT STROMLO & SIDING SPRING OBSERV, WESTON, ACT 2611, AUSTRALIA. HARVARD SMITHSONIAN CTR ASTROPHYS, CAMBRIDGE, MA 02138 USA. RP Eastman, RG (reprint author), LAWRENCE LIVERMORE NATL LAB, GEN STUDIES GRP, LIVERMORE, CA 94550 USA. OI Schmidt, Brian/0000-0001-6589-1287 NR 64 TC 122 Z9 124 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1996 VL 466 IS 2 BP 911 EP 937 DI 10.1086/177563 PN 1 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ546 UT WOS:A1996UZ54600029 ER PT J AU Provencal, JL Shipman, HL Thejll, P Vennes, S Bradley, PA AF Provencal, JL Shipman, HL Thejll, P Vennes, S Bradley, PA TI Ultraviolet spectroscopy of the DBV white dwarf star GD 358 SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars, individual (GD 358); stars, oscillations; ultraviolet, stars; white dwarfs ID TELESCOPE OBSERVATIONS; PG-1159 STARS; HELIUM; HYDROGEN; GD-358; HOT; TEMPERATURES; ATMOSPHERES; SAMPLE; THICK AB We report on analysis of UV spectra of the DBV GD 358 obtained with the Goddard High Resolution Spectrograph (GHRS) aboard the Hubble Space Telescope (HST). We confirm the detection of He II (1640 Angstrom and C II (1335 Angstrom reported by Sion et al. in 1988. The He II feature indicates a temperature of 27,000 +/- 1000 K, somewhat higher than previous estimates. We derive a carbon abundance -5.75 < log [n(C)/n(He)] < -5.55. In addition, we detect, for the first time, hydrogen in the spectrum. Whether this hydrogen is either photospheric or interstellar, the inferred photospheric upper limit is log [n(H)/n(He)] < -5, translating into a mass of <5 x 10(-18)M*. We discuss the implications of these findings on GD 358's asteroseismologically determined structure and the impact on theories of white dwarf formation and evolution. C1 NIELS BOHR INST,DK-2100 COPENHAGEN,DENMARK. UNIV CALIF BERKELEY,CTR EUV ASTROPHYS,BERKELEY,CA 94720. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Provencal, JL (reprint author), UNIV DELAWARE,DEPT PHYS & ASTRON,NEWARK,DE 19716, USA. RI Thejll, Peter/K-2959-2012; Vennes, Stephane/G-9903-2014; OI Thejll, Peter/0000-0002-5074-699X NR 33 TC 19 Z9 19 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1996 VL 466 IS 2 BP 1011 EP 1017 DI 10.1086/177571 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ546 UT WOS:A1996UZ54600037 ER PT J AU Abney, M Epstein, RI Olinto, AV AF Abney, M Epstein, RI Olinto, AV TI Observational constraints on the internal structure and dynamics of the vela pulsar SO ASTROPHYSICAL JOURNAL LA English DT Article DE magnetic fields; stars, evolution; stars, interiors; stars, neutron ID NEUTRON-STARS; SUPERFLUID CORE; QUARK STARS; DECAY AB We show that the short spin-up time observed for the Vela pulsar during the 1988 ''Christmas'' glitch implies that the coupling time of the pulsar core to its crust is less than similar to 10 s. Ekman pumping cannot explain the fast core-crust coupling and a more effective coupling is necessary. The internal magnetic field of the Vela pulsar can provide the necessary coupling if the field threads the core with a magnitude that exceeds 10(13) G for a normal interior and 10(11) G for a superconducting interior. These lower bounds favor the hypothesis that the interior of neutron stars contains superfluid neutrons and protons and challenge the notion that pulsar magnetic fields decay over million year timescales or that magnetic flux is expelled from the core as the star slows. C1 UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. RP Abney, M (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 31 TC 19 Z9 19 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1996 VL 466 IS 2 BP L91 EP L94 DI 10.1086/310171 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ547 UT WOS:A1996UZ54700010 ER PT J AU Iglesias, CA Rose, SJ AF Iglesias, CA Rose, SJ TI Corrections to bremsstrahlung and Thomson scattering at the solar center SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun, interior ID OPACITIES; INTERIOR; DEGENERACY; PLASMA; DENSE AB Corrections to inverse bremsstrahlung and Thomson scattering at the solar center from several physical effects are investigated. The major corrections are shown to be present in current stellar opacity calculations while usually neglected effects only introduce small errors. C1 RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. UNIV BIRMINGHAM,DEPT PHYS & SPACE SCI,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. RP Iglesias, CA (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. OI Rose, Steven/0000-0001-6808-6355 NR 26 TC 15 Z9 15 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1996 VL 466 IS 2 BP L115 EP L118 DI 10.1086/310172 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ547 UT WOS:A1996UZ54700015 ER PT J AU Turner, MS Truran, JW Schramm, DN Copi, CJ AF Turner, MS Truran, JW Schramm, DN Copi, CJ TI Cosmological implications of the first measurement of the local ISM abundance of He-3 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology, theory; galaxy, abundances; galaxy, evolution; ISM, abundances; nuclear reactions, nucleosynthesis, abundances ID BIG-BANG NUCLEOSYNTHESIS; RED GIANT STARS; INTERSTELLAR-MEDIUM; PRIMORDIAL NUCLEOSYNTHESIS; DEUTERIUM; SOLAR; EVOLUTION; HELIUM; CIRCULATION; C-12/C-13 AB Deuterium plays a crucial role in testing big bang nucleosynthesis. However, its chemical evolution is intertwined with that of He-3. Gloeckler & Geiss's new measurement of the He-3 abundance and the Hubble Space Telescope measurement of D, both in the local ISM today, can be compared to the presolar nebula abundances of D and He-3. Within the uncertainties, the sum of D + He-3 relative to hydrogen is unchanged. This indicates that over the past 4.5 Gyr there has been at most modest stellar production of He-3, in contradiction with stellar modeling, or modest stellar destruction of He-3, in contradiction with efficient ''solar spoons.'' The constancy of D + He-3 alleviates some of the cosmic tension between the big bang He-4 abundance and those of D and He-3. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP Turner, MS (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637, USA. NR 51 TC 14 Z9 14 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1996 VL 466 IS 2 BP L59 EP L62 DI 10.1086/310173 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ547 UT WOS:A1996UZ54700002 ER PT J AU Weston, RE AF Weston, RE TI Possible greenhouse effects of tetrafluoromethane and carbon dioxide emitted from aluminum production SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE aluminum production; atmospheric halocarbons; global warming; radiative forcing; tetrafluoromethane ID STRATOSPHERE; CLIMATE; HALOCARBONS; ATMOSPHERE; TRENDS; MODEL; CF4 AB Tetrafluoromethane (CF4) is an extremely stable gas which strongly absorbs infrared radiation at similar to 8 mu m, and therefore is capable of influencing the greenhouse effect. No natural sources have been identified, and the major anthropogenic source appears to be the electrolytic smelting of alumina to produce aluminum. Measurements of CF4 concentrations in the atmosphere are reviewed, and these are combined with aluminum production rates to provide an estimate of 1.3-3.6 kg of CF4 emitted per ton of aluminum produced for the period up to similar to 1985. Aluminum production also requires large amounts of electrical energy, leading to the emission, of as much as 22 tons of carbon dioxide per ton of aluminum due to fossil fuel combustion in power plants; The,present day contribution of hydroelectric power reduces this figure to about 14 tons of carbon dioxide per ton of aluminum. An estimate of the relative radiative trapping of CF4 and CO2 emitted in aluminum production during this same period (1900-1985) indicates that the effect of CF4 is about one-third that of the CO2 formed by. aluminum production. However, the emission of fluorocarbons from modem aluminum electrolysis cells is much lower than previous estimates indicate, and this factor is considered in estimating potential long-term global warming effects of CF4 and CO2 from aluminum production. Possible processes leading to removal of CF4 from the atmosphere are described. Copyright (C) 1996 Elsevier Science Ltd RP Weston, RE (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,POB 5000,UPTON,NY 11973, USA. NR 47 TC 12 Z9 12 U1 2 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD AUG PY 1996 VL 30 IS 16 BP 2901 EP 2910 DI 10.1016/1352-2310(95)00499-8 PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UN628 UT WOS:A1996UN62800010 ER PT J AU Akhmedova, SN Pushnova, EA Anisimov, S Bogdanova, LA Bova, LK Schwartz, EI AF Akhmedova, SN Pushnova, EA Anisimov, S Bogdanova, LA Bova, LK Schwartz, EI TI CYP2D6 genotyping in a Russian population using a novel approach for identification of the CYP2D6A mutation SO BIOCHEMICAL AND MOLECULAR MEDICINE LA English DT Article ID GENETIC-POLYMORPHISM; DRUG-METABOLISM; DEBRISOQUINE; HYDROXYLATION; SUSCEPTIBILITY; CANCER; MEPHENYTOIN; PHENOTYPES; OXIDATION; SEQUENCE AB The frequency of 29A and 29B mutations in the CYP2D6 gene, the most common mutations among Caucasoid PM (debrisoquine 4-hydroxylase defficient) individuals, has been analyzed in the Russian population. For the detection of the 29A mutation, a new one-step ARMS PCR approach has been developed. The frequency of the 29B mutant allele in Russians appeared to be significantly lower than in other Caucasoid populations, and this observation can be explained by the mixed origin of the population inhabiting Russia, Comparative analysis of the mutation frequencies among individuals of various ages showed no age-related differences. (C) 1996 Academic Press, Inc. C1 PETERSBURG INST NUCL PHYS,GATCHINA 188350,ST PETERSBURG R,RUSSIA. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. ST PETERSBURG PEDIAT MED ACAD,DEPT MED GENET,ST PETERSBURG 194100,RUSSIA. ST PETERSBURG MUNICIPAL GERIATR CTR,ST PETERSBURG 196066,RUSSIA. NR 17 TC 0 Z9 1 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1077-3150 J9 BIOCHEM MOL MED JI Biochem. Mol. Med. PD AUG PY 1996 VL 58 IS 2 BP 234 EP 236 DI 10.1006/bmme.1996.0054 PG 3 WC Biochemistry & Molecular Biology; Medicine, Research & Experimental SC Biochemistry & Molecular Biology; Research & Experimental Medicine GA VB361 UT WOS:A1996VB36100014 PM 8812745 ER PT J AU Krauter, P Martinelli, R Williams, K Martins, S AF Krauter, P Martinelli, R Williams, K Martins, S TI Removal of Cr(VI) from ground water by Saccharomyces cerevisiae SO BIODEGRADATION LA English DT Article DE Saccharomyces cerevisiae; bioaccumulation; chromium; ground water ID HEAVY-METAL; ESCHERICHIA-COLI; REDUCTION; ACCUMULATION; BACTERIA; CHROMIUM; MICROORGANISMS; CHROMATE AB Chromium can be removed from ground water by the unicellular yeast, Saccharomyces cerevisiae. Local ground water maintains chromium as CrO42- because of bicarbonate buffering and pH and Eh conditions (8.2 and +343 mV, respectively). In laboratory studies, we used commercially available, nonpathogenic S. cerevisiae to remove hexavalent chromium [Cr(VI)] from ground water. The influence of parameters such as temperature, pH, and glucose concentration on Cr(VI) removal by yeast were also examined. S. cerevisiae removed Cr(VI) under aerobic and anaerobic conditions, with a slightly greater rate occurring under anaerobic conditions. Our kinetic studies reveal a reaction rate (V-max) of 0.227 mg h(-1) (g dry wt biomass)(-1) and a Michaelis constant (Km) of 145 mg/l in natural ground water using mature S. cerevisiae cultures. We found a rapid (within 2 minutes) initial removal of Cr(VI) with freshly hydrated cells [55-67 mg h(-1) (g dry wt biomass)(-1)] followed by a much slower uptake [0.6-1.1 mg h(-1) (g dry wt biomass)(-1)] that diminished with time. A materials-balance for a batch reactor over 24 hours resulted in an overall shift in redox potential from +321 to +90 mV, an increase in the bicarbonate concentration (150-3400 mg/l) and a decrease in the Cr(VI) concentration in the effluent (1.9-0 mg/l). C1 LAWRENCE LIVERMORE NATL LAB,HLTH & ECOL ASSESSMENT DIV,LIVERMORE,CA 94550. RP Krauter, P (reprint author), LAWRENCE LIVERMORE NATL LAB,ENVIRONM PROTECT DEPT,LIVERMORE,CA 94550, USA. NR 22 TC 53 Z9 56 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0923-9820 J9 BIODEGRADATION JI Biodegradation PD AUG PY 1996 VL 7 IS 4 BP 277 EP 286 DI 10.1007/BF00115741 PG 10 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA VY775 UT WOS:A1996VY77500001 PM 8987886 ER PT J AU Katul, G Hsieh, CI Oren, R Ellsworth, D Phillips, N AF Katul, G Hsieh, CI Oren, R Ellsworth, D Phillips, N TI Latent and sensible heat flux predictions from a uniform pine forest using surface renewal and flux variance methods SO BOUNDARY-LAYER METEOROLOGY LA English DT Article ID COHERENT STRUCTURES; UNSTABLE CONDITIONS; TURBULENT TRANSFER; LAYER TURBULENCE; DECIDUOUS FOREST; WAVELET ANALYSIS; LOCAL ISOTROPY; SHEAR-STRESS; TEMPERATURE; CANOPY AB A surface renewal model that links organized eddy motion to the latent and sensible heat fluxes is tested with eddy correlation measurements carried out in a 13 m tall uniform Loblolly pine plantation in Duke Forest, Durham, North Carolina. The surface renewal model is based on the occurance of ramp-like patterns in the scalar concentration measurements. To extract such ramp-like patterns from Eulerian scalar concentration measurements, a newly proposed time-frequency filtering scheme is developed and tested. The time-domain filtering is carried out using compactly-supported orthonormal wavelets in conjunction with the ''Universal Wavelet Thresholding'' approach of Donoho and Johnstone, while the frequency filtering is carried out by a band-pass sine filter centered around the ramp-occurrence Frequency as proposed by other studies. The method was separately tested for heat and water vapour with good agreement between eddy correlation flux measurements and model predictions. The usefulness of the flux-variance method to predict sensible and latent heat fluxes is also considered. Our measurements suggest that the simple flux-variance method reproduces the measured heat and momentum fluxes despite the fact that the variances were measured within the roughness sublayer and not in the surface layer. Central to the predictions of water vapour fluxes using the flux-variance approach is the similarity between heat and water vapour transport by the turbulent air flow. This assumption is also investigated for this uniform forest terrain. C1 DUKE UNIV,CTR HYDROL SCI,DURHAM,NC 27708. CALTECH,JET PROP LAB,PASADENA,CA 91109. BROOKHAVEN NATL LAB,BIOSYST & PROC SCI DIV,UPTON,NY 11973. RP Katul, G (reprint author), DUKE UNIV,SCH ENVIRONM,DURHAM,NC 27708, USA. RI Katul, Gabriel/A-7210-2008; OI Katul, Gabriel/0000-0001-9768-3693; Ellsworth, David/0000-0002-9699-2272 NR 89 TC 63 Z9 64 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD AUG PY 1996 VL 80 IS 3 BP 249 EP 282 PG 34 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VU198 UT WOS:A1996VU19800003 ER PT J AU Taylor, SR AF Taylor, SR TI Analysis of high-frequency P-g/L(g) ratios from NTS explosions and western US earthquakes SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID UNITED-STATES EARTHQUAKES; SPECTRAL DISCRIMINATION; NUCLEAR-EXPLOSIONS; YIELD ESTIMATION; NEURAL NETWORKS; REGIONAL DATA; WAVES AB The high-frequency P-g/L(g) discriminant is studied between frequencies of 0.5 and 10 Hz using 294 NTS explosions and 114 western U.S. earthquakes recorded at four broadband seismic stations operated by Lawrence Livermore National Laboratory. The stations are located at distances of about 200 to 400 km from the Nevada Test Site (NTS). Event magnitudes ranged from about 2.5 to 6.5, and propagation paths for the earthquakes range from approximately 175 to 1300 km. The discriminant is shown to be very effective and displays improved separation between earthquakes and explosions as frequency is increased. Because of propagation effects, it is important to apply distance corrections directly to the amplitude ratios or to the magnitude-corrected amplitudes prior to computing the ratios. Multivariate discrimination analysis using both maximum-likelihood Gaussian classifiers and a backpropagation neural network show that approximately 95% of the events can be correctly identified. Both classification procedures were designed to handle missing data filled in using a nearest-neighbor algorithm. Except for a few notable exceptions, most of the earthquake misclassifications occur for m(b) < 4, which is expected for events having reduced signal-to-noise ratios. All of the explosion misclassifications occur for m(b) > 4, suggesting a source or near-source effect rather than an effect of poor signal-to-noise ratio. The explosions that were misclassified were typically of magnitude large enough to be classified correctly by m(b)/M(s) or Love-wave energy. The main drawback of-the P-g/L(g) discriminant is that, because of signal-to-noise considerations and propagation effects, the number of measurements are reduced considerably at higher frequencies. It is expected that the problem will be amplified as magnitudes are reduced and event-receiver distances are increased. RP Taylor, SR (reprint author), LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545, USA. NR 29 TC 48 Z9 55 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD AUG PY 1996 VL 86 IS 4 BP 1042 EP 1053 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VD746 UT WOS:A1996VD74600012 ER PT J AU Jarpe, SP Kasameyer, PW AF Jarpe, SP Kasameyer, PW TI Validation of a procedure for calculating broadband strong-motion time histories with empirical Green's functions SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID STRONG GROUND MOTION; LOMA-PRIETA EARTHQUAKE; IMPERIAL-VALLEY; SAN-FRANCISCO; WAVE-FORM; CALIFORNIA; INVERSION; RUPTURE; AFTERSHOCKS; MODELS AB We quantitatively evaluate the validity of an approach to calculating strong ground motion time histories that involves the kinematic modeling of earthquake rupture by using recorded empirical Green's functions to constrain the propagation path and site contribution in the period range 0.05 to 2.0 sec, leaving only the contribution of the source to be specified. In addition, we use numerical Green's functions for long periods (>10 sec) where the average crustal structure is assumed to be well known. In the intermediate band (2 to 10 sec) where site and path effects are still important but empirical Green's functions have small signal-to-noise ratios, we use an arbitrary smoothing method to connect the numerical and empirical Green's function synthetics. The evaluation presented here consists of comparing actual recordings of the Loma Prieta earthquake at 26 sites to syntheses from a simple source model similar to what is thought to have occurred during the Loma Prieta earthquake. We show that the standard error between observed and predicted response spectra is less than or equal to errors from other methods for periods between 0.05 and 0.4 sec and is significantly less than regression methods based on pre-Loma Prieta empirical strong-motion data at periods between 0.5 and 5.0 sec. The strong ground motion prediction methodology that we are validating provides an accurate, defendable means to characterize site and path effects and, therefore, allows the uncertainties in the predicted hazard to be due to unresolved issues about the earthquake source such as the geological constraints of a particular fault and details about the physics of earthquakes. This methodology produces accurate and realistic acceleration and displacement time histories, which are becoming increasingly important for modeling the nonlinear response of large, distributed structures and soft soils. The implication for strong ground motion prediction is that a range of representations of-an earthquake source based on physically realistic parameters can be used to generate a suite of possible time histories that represent the range of ground motion for that specific site and earthquake. In addition, in the future, as more information about a particular fault and earthquakes in general becomes available, the uncertainty in ground-motion prediction should decrease. RP Jarpe, SP (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808 L-205,LIVERMORE,CA 94551, USA. NR 61 TC 19 Z9 21 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD AUG PY 1996 VL 86 IS 4 BP 1116 EP 1129 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VD746 UT WOS:A1996VD74600018 ER PT J AU Zitzelsberger, H Szucs, S Robens, E Weier, HU Hofler, H Bauchinger, M AF Zitzelsberger, H Szucs, S Robens, E Weier, HU Hofler, H Bauchinger, M TI Combined cytogenetic and molecular genetic analyses of fifty-nine untreated human prostate carcinomas SO CANCER GENETICS AND CYTOGENETICS LA English DT Article ID IN-SITU HYBRIDIZATION; FLUORESCENCE INSITU HYBRIDIZATION; CHROMOSOME REARRANGEMENTS; DNA HYBRIDIZATION; CANCER; ADENOCARCINOMA; TISSUE; CELLS; FISH; ABNORMALITIES AB G-banding analyses and molecular gene-tie investigations (fluorescence in situ hybridization (FISH) and loss of heterozygosity (LOH) studies) were performed in 59 tumor and nontumorous samples of human prostate carcinoma. Clonal chromosome aberrations were detected in 16 tumors of which nine were poorly differentiated (G3) and 11 in an advanced stage (pT3). Six cases showed numerical chromosome aberrations, The most common numerical aberrations were trisomy 7 and loss of the Y chromosome each present in three tumors, Clonal structural aberrations were detected in 12 tumors. Deletions could be observed in two cases affecting chromosome 6q23 and in two cases affecting chromosomal region 16q, A structural variant of the pericentromeric heterochromatin of chromosome 9 became apparent in six cases. The Y chromosome was involved in clonal translocations in two cases, additionally an inversion occurred on chromosome 19 in one case. All clonal chromosomal changes were found exclusively in the tumor sample, For an analysis of the pericentromeric heterochromatin of chromosome 9, FISH using a chromosome 9-specific sat III DNA probe was carried out on metaphase preparations of tumor and nontumorous tissues of two cases showing var(9)(qh). The FISH data suggest a deletion in the pericentromeric heterochromatin. Loss of heterozygosity studies on chromosomal regions 10q and 16q were carried out because both chromosomes were frequently affected by nonclonal structural aberrations. Loss of heterozygosity could be verified in 11 cases. C1 GSF FORSCHUNGSZENTRUM UNWELT & GESUNDHEIT GMBH,INST STRAHLENBIOL,MUNICH,GERMANY. TECH UNIV MUNICH,INST PATHOL & PATHOL ANAT,D-8000 MUNICH,GERMANY. GSF FORSCHUNGSZENTRUM UNWELT & GESUNDHEIT GMBH,INST PATHOL,MUNICH,GERMANY. LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA. NR 45 TC 20 Z9 20 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0165-4608 J9 CANCER GENET CYTOGEN JI Cancer Genet. Cytogenet. PD AUG PY 1996 VL 90 IS 1 BP 37 EP 44 DI 10.1016/0165-4608(96)00065-9 PG 8 WC Oncology; Genetics & Heredity SC Oncology; Genetics & Heredity GA VE550 UT WOS:A1996VE55000007 PM 8780745 ER PT J AU Tanner, MM Tirkkonen, M Kallioniemi, A Isola, J Kuukasjarvi, T Collins, C Kowbel, D Guan, XY Trent, J Gray, JW Meltzer, P Kallioniemi, OP AF Tanner, MM Tirkkonen, M Kallioniemi, A Isola, J Kuukasjarvi, T Collins, C Kowbel, D Guan, XY Trent, J Gray, JW Meltzer, P Kallioniemi, OP TI Independent amplification and frequent co-amplification of three nonsyntenic regions on the long arm of chromosome 20 in human breast cancer SO CANCER RESEARCH LA English DT Article ID COMPARATIVE GENOMIC HYBRIDIZATION; DNA AMPLIFICATION; SEQUENCES; TUMORS AB DNA amplification at 20q13.2 is common in breast cancer, correlates with poor prognosis, and may reflect location of an important oncogene. Recently, other regions along 20q were also found to undergo amplification. Here, amplification levels and patterns of co-amplification were analyzed by interphase fluorescence in situ hybridization at 14 loci along 20q in 146 uncultured breast carcinomas and 14 cell lines. Three regions were independently amplified in uncultured tumors: RMC20C001 region at 20q13.2 (highly amplified in 9.6% of the cases), PTPN1 region 3 Mb proximal (6.2%), and AIB3 region at 20q11 (6.2%), Co-amplifications involving two or three of these regions were seen in 11 of the 19 highly amplified tumors. The results suggest that three distinct nonsyntenic regions along 20q may be important and that complex chromosomal rearrangements underlie their frequent co-amplification in breast cancer. C1 TAMPERE UNIV, FIN-33101 TAMPERE, FINLAND. NIH, CANC GENET LAB, NATL CTR HUMAN GENOME RES, BETHESDA, MD 20892 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV LIFE SCI, BERKELEY, CA 94720 USA. UNIV CALIF SAN FRANCISCO, DEPT LAB MED, DIV MOL CYTOMETRY, SAN FRANCISCO, CA 94143 USA. RP Tanner, MM (reprint author), TAMPERE UNIV HOSP, INST MED TECHNOL, CANC GENET LAB, BOX 607, FIN-33101 TAMPERE, FINLAND. RI Guan, Xin-Yuan/A-3639-2009; Kallioniemi, Olli/H-5111-2011; Kallioniemi, Olli/H-4738-2012; OI Guan, Xin-Yuan/0000-0002-4485-6017; Kallioniemi, Olli/0000-0002-3231-0332; Kallioniemi, Olli/0000-0002-3231-0332; Kallioniemi, Anne/0000-0003-3552-8158 FU NCI NIH HHS [CA58207] NR 20 TC 168 Z9 168 U1 1 U2 8 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA PUBLIC LEDGER BLDG, SUITE 816, 150 S. INDEPENDENCE MALL W., PHILADELPHIA, PA 19106 SN 0008-5472 J9 CANCER RES JI Cancer Res. PD AUG 1 PY 1996 VL 56 IS 15 BP 3441 EP 3445 PG 5 WC Oncology SC Oncology GA UZ288 UT WOS:A1996UZ28800012 PM 8758909 ER PT J AU Hall, LL Thng, JPH Guo, XW Teplitz, RL Bradbury, EM AF Hall, LL Thng, JPH Guo, XW Teplitz, RL Bradbury, EM TI A brief staurosporine treatment of mitotic cells triggers premature exit from mitosis and polyploid cell formation SO CANCER RESEARCH LA English DT Article ID LYSINE-RICH HISTONE; NUCLEAR-DNA CONTENT; PROTEIN-KINASES; POTENT INHIBITOR; MAMMALIAN-CELLS; MAMMARY ADENOCARCINOMAS; PULMONARY CYTOLOGY; SODIUM-BUTYRATE; IMAGE-ANALYSIS; FISSION YEAST AB At any point during the progression of many tumor types, cells can develop a hyperploid DNA content. Hyperploid tumors are significantly more aggressive, with a higher growth rate and a poor patient prognosis, Yeast genetics have implicated three important genes involved in DNA ploidy changes: cdc2, cyclin b, and a specific inhibitor of the p34(cdc2)/cyclin B kinase, rum1. Mutations in these genes uncoupled the dependence of mitosis on DNA replication in the fission yeast, Saccharomyces pombe, It was proposed that the inactivation of the mitotic kinase complex, p34(cdc2)/cyclin B, induces a G(1) state wherein the cells re-replicate their DNA without an intervening mitosis. We show in this report that treatment of only M phase-arrested mouse cells, with the protein kinase inhibitor staurosporine, induced polyploidy, Nocodazole-arrested metaphase FT210 cells were pulsed with 100 ng/ml of staurosporine for 1 h, This 1-h treatment results in the inhibition of the mitotic p34(cdc2) kinase. The inhibition of the mitotic kinases leads to a reduction in the histone H1 and H3 mitotic-associated phosphorylations, chromosome decondensation, and nuclear membrane reformation. When released into normal growth medium, these cells are reset to a G(1) state, re-replicate their DNA without completing mitosis, and become octaploid. C1 MCGILL UNIV,JEWISH GEN HOSP,LADY DAVIS INST,BLOOMFIELD CTR RES AGING,MONTREAL,PQ H3T 1E2,CANADA. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. RP Hall, LL (reprint author), UNIV CALIF DAVIS,SCH MED,DEPT BIOL CHEM,DAVIS,CA 95616, USA. FU NIGMS NIH HHS [GM45890] NR 76 TC 41 Z9 42 U1 0 U2 0 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA PUBLIC LEDGER BLDG, SUITE 816, 150 S. INDEPENDENCE MALL W., PHILADELPHIA, PA 19106 SN 0008-5472 J9 CANCER RES JI Cancer Res. PD AUG 1 PY 1996 VL 56 IS 15 BP 3551 EP 3559 PG 9 WC Oncology SC Oncology GA UZ288 UT WOS:A1996UZ28800030 PM 8758926 ER PT J AU Lingle, RL Ge, NH Jordan, RE McNeill, JD Harris, CB AF Lingle, RL Ge, NH Jordan, RE McNeill, JD Harris, CB TI Femtosecond studies of electron tunneling at metal-dielectric interfaces (vol 205, pg 191, 1996) SO CHEMICAL PHYSICS LA English DT Correction, Addition C1 UNIV CALIF BERKELEY,EO LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Lingle, RL (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI McNeill, Jason/E-5389-2011 NR 1 TC 19 Z9 19 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD AUG 1 PY 1996 VL 208 IS 2 BP 297 EP 298 DI 10.1016/0301-0104(96)00136-X PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UY674 UT WOS:A1996UY67400010 ER PT J AU Tutterow, VC Doolin, JH Paul, BO AF Tutterow, VC Doolin, JH Paul, BO TI Energy-efficient pumping systems SO CHEMICAL PROCESSING LA English DT Article C1 HYDRAUL INST,PARSIPPANY,NJ. RP Tutterow, VC (reprint author), ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,WASHINGTON,DC, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU PUTMAN PUBL CO PI CHICAGO PA 301 E ERIE STREET, CHICAGO, IL 60611 SN 0009-2630 J9 CHEM PROCESS JI Chem. Process. PD AUG PY 1996 VL 59 IS 8 BP 30 EP & PG 5 WC Engineering, Chemical SC Engineering GA VC715 UT WOS:A1996VC71500005 ER PT J AU Raman, NK Anderson, MT Brinker, CJ AF Raman, NK Anderson, MT Brinker, CJ TI Template-based approaches to the preparation of amorphous, nanoporous silicas SO CHEMISTRY OF MATERIALS LA English DT Review ID MESOPOROUS MOLECULAR-SIEVES; SOL-GEL METHOD; STRUCTURE-DIRECTION; HYDROCARBON TEMPLATES; KNUDSEN DIFFUSIVITIES; PLASMA OXIDATION; POROUS MATERIALS; ACID CATALYST; THIN-FILMS; MCM-41 AB This review discusses two classes of organic template-derived amorphous silicas distinguished by the nature of template-matrix interactions and the extent to which subsequent processing dictates the final pore morphology. First we discuss surfactant-templated silicas where the template-matrix interaction is via non-covalent bonding mechanisms and the pore structure is established in the solution stage. We then discuss silicas templated by organic ligands covalently bonded to the siloxane network where subsequent processing strongly influences the final pore structure. C1 UNIV NEW MEXICO, NSF, CTR MICROENGINEERED CERAM, ALBUQUERQUE, NM 87131 USA. SANDIA NATL LABS, CERAM SYNTH & INORGAN CHEM DEPT, ADV MAT LAB, ALBUQUERQUE, NM 87106 USA. NR 169 TC 610 Z9 614 U1 17 U2 183 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 EI 1520-5002 J9 CHEM MATER JI Chem. Mat. PD AUG PY 1996 VL 8 IS 8 BP 1682 EP 1701 DI 10.1021/cm960138+ PG 20 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VC732 UT WOS:A1996VC73200016 ER PT J AU Calvert, P Rieke, P AF Calvert, P Rieke, P TI Biomimetic mineralization in and on polymers SO CHEMISTRY OF MATERIALS LA English DT Review ID DIRECTED INORGANIC CRYSTALLIZATION; COMPRESSED LANGMUIR MONOLAYERS; SELF-ASSEMBLED MONOLAYERS; MOLECULAR-SIEVE CRYSTALS; AIR-WATER-INTERFACE; X-RAY-DIFFRACTION; CALCIUM-CARBONATE; AMPHIPHILIC ALCOHOLS; ORIENTED NUCLEATION; ACID MONOLAYERS AB Biological mineralization leads to the development of finely scaled, highly controlled inorganic precipitates in organic matrixes. mainly exercised through lattice-matching epitaxy between the protein or polysaccharide matrix and the mineral. We discuss the importance of such heterogeneous nucleation versus other forms of kinetic control of mineralization. We review progress in synthetic systems for mineralization from solution at Langmuir monolayers and Langmuir-Blodgett films, at surface-adsorbed monolayers and in polymer films. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Calvert, P (reprint author), UNIV ARIZONA, ARIZONA MAT LAB, TUCSON, AZ 85712 USA. NR 112 TC 137 Z9 138 U1 2 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD AUG PY 1996 VL 8 IS 8 BP 1715 EP 1727 DI 10.1021/cm960126o PG 13 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VC732 UT WOS:A1996VC73200018 ER PT J AU Bley, RA Kauzlarich, SM Davis, JE Lee, HWH AF Bley, RA Kauzlarich, SM Davis, JE Lee, HWH TI Characterization of silicon nanoparticles prepared from porous silicon SO CHEMISTRY OF MATERIALS LA English DT Article ID BLUE-LIGHT EMISSION; INFRARED-SPECTROSCOPY; VISIBLE LUMINESCENCE; SMALL PARTICLES; SI; NANOCRYSTALS; GAS AB Nanometer-sized silicon particles have been produced by ultrasonic dispersion of thin sections of porous silicon (PS) in organic solvents. The particles have been characterized by HRTEM (high-resolution transmission electron microscopy), FTIR (Fourier transform infrared) spectroscopy, and fluorescence spectroscopy. HRTEM shows both aggregates of and monodispersed crystallite particles of Si. The larger aggregates range in size from 20 to 50 nm and are made up of small crystallites with diameters of 2-10 nm. Monodispersed crystallites ranged in size from 2-10 nm. All the particles have an amorphous layer of SiO2. The photoluminescence (PL) spectrum shows two peaks: a red peak at around 680 nm, which is typical for PS and a blue peak between 415 and 446 nm, which is not typical for as-prepared PS. As a function of increased excitation intensity, the blue peak grows at the expense of the red. This is discussed in light of photoluminescence lifetime data. The red luminescence is attributed to quantum confinement. The blue luminescence is attributed to either extremely small Si crystallites or (Si(II))(0) defects embedded in the oxide matrix. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF DAVIS,DEPT APPL SCI,DAVIS,CA 95616. RP Bley, RA (reprint author), UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616, USA. NR 28 TC 70 Z9 70 U1 3 U2 36 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD AUG PY 1996 VL 8 IS 8 BP 1881 EP 1888 DI 10.1021/cm950608k PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VC732 UT WOS:A1996VC73200034 ER PT J AU Kane, MS Goellner, JF Foley, HC DiFrancesco, R Billinge, SJL Allard, LF AF Kane, MS Goellner, JF Foley, HC DiFrancesco, R Billinge, SJL Allard, LF TI Symmetry breaking in nanostructure development of carbogenic molecular sieves: Effects of morphological pattern formation on oxygen and nitrogen transport SO CHEMISTRY OF MATERIALS LA English DT Article ID CARBON; SEPARATION; ADSORBENTS; PARTICLES AB A comprehensive study has been undertaken to establish the primary factors that control transport of oxygen and nitrogen in polymer-derived carbogenic molecular sieves (CMS). Characterization of the nanostructure of CMS derived from poly(furfuryl alcohol) (PFA) indicates that significant physical and chemical reorganization occurs as a function of synthesis temperature. Spectroscopic measurements show a drastic decrease in oxygen and hydrogen functionality with increasing pyrolysis temperature. Structural reorganization and elimination of these heteroatoms lead to a measurable increase in the unpaired electron density in these materials. High-resolution transmission electron microscopy and powder neutron diffraction are used to probe the corresponding changes in the physical structural features in the CMS. These indicate that as the pyrolysis temperature is increased, the structure of the CMS transforms from one that is disordered and therefore highly symmetric to one that is more ordered on a length scale of 15 Angstrom and hence less symmetric. This structural transformation process, one of symmetry breaking and pattern formation, is often observed in other nonlinear dissipative systems, but not in solids. Symmetry breaking provides the driving force for these high-temperature reorganizations, but unlike most dissipative systems, these less-symmetric structures remain frozen in place when energy is no longer applied. The impact of these nanostructural reorganizations on the molecular sieving character of the CMS is studied in terms of the physical separation of oxygen and nitrogen. These results show that the effective diffusivities of oxygen and nitrogen in the CMS vary by more than an order of magnitude across the range of synthesis temperatures studied. Although the electronic nature of the CMS leads to higher equilibrium capacity for oxygen, it is the physical nanostructure which governs the separation of these two molecules. It is concluded that the primary separation mechanism is steric and configurational in nature, a conclusion in good agreement with the general features of the kinetic hypothesis conjectured by earlier workers. C1 MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. RP Kane, MS (reprint author), UNIV DELAWARE,DEPT CHEM ENGN,CTR CATALYT SCI & TECHNOL,NEWARK,DE 19716, USA. NR 40 TC 29 Z9 29 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD AUG PY 1996 VL 8 IS 8 BP 2159 EP 2171 DI 10.1021/cm960085w PG 13 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VC732 UT WOS:A1996VC73200069 ER PT J AU Carrado, KA Thiyagarajan, P Elder, DL AF Carrado, KA Thiyagarajan, P Elder, DL TI Polyvinyl alcohol clay complexes formed by direct synthesis SO CLAYS AND CLAY MINERALS LA English DT Article DE clays; direct synthesis; hectorite; hydrothermal crystallization; polymer clays; polyvinyl alcohol; PVA ID INVERSE GAS-CHROMATOGRAPHY; HYDROTHERMAL CRYSTALLIZATION; LAYERED SILICATE; MINERALS; INTERCALATION; MONTMORILLONITE; NANOCOMPOSITES; MICA AB Synthetic hectorite clay minerals were hydrothermally crystallized with direct incorporation of a series of five water-soluble polyvinyl alcohols (PVA) of molecular weights from 9000-146,000, The molecular weight of PVA had little effect on the success of hydrothermal hectorite synthesis, d-spacing or the amount of polymer incorporated. The basal spacings range from 19.5 Angstrom to 20.8 Angstrom and the amount of polymer incorporated ranges from 20 wt.% to 23 wt.%. incorporation of PVA within the clay interlayers, along with Li(I) ions to compensate the lattice charge, is indicated. Thermal gravimetric analysis and small angle neutron scattering were used to further examine the polymer-clay systems. Small PVA-clay crystallites that are coated with excess PVA are indicated. Removal of the polymer does not alter the extended synthetic clay network, and the nitrogen BET surface area increases from <5 m(2)/g to >200 m(2)/g. C1 ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. RP Carrado, KA (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 32 TC 62 Z9 63 U1 2 U2 14 PU CLAY MINERALS SOCIETY PI BOULDER PA PO BOX 4416, BOULDER, CO 80306 SN 0009-8604 J9 CLAY CLAY MINER JI Clay Clay Min. PD AUG PY 1996 VL 44 IS 4 BP 506 EP 514 DI 10.1346/CCMN.1996.0440409 PG 9 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA VF393 UT WOS:A1996VF39300009 ER PT J AU Superko, HR AF Superko, HR TI Cost-effective treatment of coronary artery disease - The new imperative SO CLINICAL CARDIOLOGY LA English DT Article DE cholesterol; low-density lipoprotein cholesterol; small low-density lipoprotein; lipoproteins; cost analysis; lipoprotein subclass ID MONITORED ATHEROSCLEROSIS REGRESSION; LOW-DENSITY LIPOPROTEINS; HEART-DISEASE; MYOCARDIAL-INFARCTION; ANGIOGRAPHIC BENEFIT; CLINICAL EVENTS; FOLLOW-UP; CHOLESTEROL; PROGRESSION; RISK AB Large lipid-lowering clinical trials have demonstrated a significant reduction in cardiovascular events and the need for cardiovascular procedures. These clinical end point trials used relatively weak treatment modalities, and when the cost savings of the reduced number of events is balanced against the estimated cost of treatment, the average difference is approximately $1,500 per patient per year. Arteriographic trials have used similar or more aggressive lipoprotein therapy over shorter periods of time. Estimates of cost savings from reduced clinical events balanced against the cost of treatment in these studies indicate a wide spectrum of estimated patient costs. These estimates range between a cost of $2,273 per patient per year to a cost savings of -$901 per patient per year. Extrapolation to the United States population with coronary artery disease (CAD) suggests that greater than one billion dollars per year could be saved if patients with CAD received similar treatment and responded in a similar manner. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA. RP Superko, HR (reprint author), CHOLESTEROL GENET & HEART DIS INST,1875 SO GRANT ST,SUITE 700,SAN MATEO,CA 94402, USA. OI Superko, H. Robert/0000-0002-3542-0393 NR 40 TC 3 Z9 3 U1 1 U2 1 PU CLINICAL CARDIOLOGY PUBL CO PI MAHWAH PA PO BOX 832, MAHWAH, NJ 07430-0832 SN 0160-9289 J9 CLIN CARDIOL JI Clin. Cardiol. PD AUG PY 1996 VL 19 IS 8 BP 650 EP 655 PG 6 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA VA797 UT WOS:A1996VA79700011 PM 8864339 ER PT J AU Murray, PE AF Murray, PE TI Numerical simulation of coalescence of inviscid drops at a solid surface SO COMMUNICATIONS IN NUMERICAL METHODS IN ENGINEERING LA English DT Article DE inviscid drops; coalescence; boundary element method ID OSCILLATIONS AB A numerical method is used to simulate the motion of inviscid drops colliding and coalescing at a solid surface. The equations of motion are solved by a boundary element method in which the free surface of the drop is represented by a moving grid. The numerical results include the configuration of the drop during coalescence and the kinetic and potential energies. A numerical example is used to demonstrate the way in which coalescence affects the configuration of the free surface. RP Murray, PE (reprint author), LOCKHEED IDAHO TECHNOL CO,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 8 TC 2 Z9 2 U1 1 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1069-8299 J9 COMMUN NUMER METH EN JI Commun. Numer. Methods Eng. PD AUG PY 1996 VL 12 IS 8 BP 447 EP 454 DI 10.1002/(SICI)1099-0887(199608)12:8<447::AID-CNM978>3.0.CO;2-L PG 8 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA VD300 UT WOS:A1996VD30000001 ER PT J AU Grein, CH Benedek, R delaRubia, T AF Grein, CH Benedek, R delaRubia, T TI Epitaxial growth simulation employing a combined molecular dynamics and Monte Carlo approach SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Virtual MBE CY JUN 15-17, 1995 CL HUGHES RES LABS, MALIBU, CA SP NIST, Ctr Theory & Comp Mat Sci HO HUGHES RES LABS ID FILM GROWTH; VAPOR-DEPOSITION; BEAM EPITAXY; MBE GROWTH; SILICON; GERMANIUM; SI1-XGEX; SURFACE; SI AB The epitaxial growth of Ge on Si(001) is simulated by employing a hybrid approach based on molecular dynamics to describe the initial kinetic behavior of deposited adatoms and Monte Carlo displacements to account for subsequent equilibration. This method is well suited to describe initial nucleation and growth. Stillinger-Weber potentials are employed to describe interatomic interactions. C1 UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550. NR 30 TC 12 Z9 12 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD AUG PY 1996 VL 6 IS 2 BP 123 EP 126 DI 10.1016/0927-0256(96)00025-0 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA VJ932 UT WOS:A1996VJ93200003 ER PT J AU Tsao, JY AF Tsao, JY TI A review of reflection mass spectrometry during III/V MBE SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Virtual MBE CY JUN 15-17, 1995 CL HUGHES RES LABS, MALIBU, CA SP NIST, Ctr Theory & Comp Mat Sci HO HUGHES RES LABS ID MOLECULAR-BEAM EPITAXY; SURFACE-STOICHIOMETRY; GAAS; GROWTH; DESORPTION; ALGAAS; AS-4; ALAS; INAS AB This paper reviews the use of line-of-sight mass spectrometry for in situ monitoring during MBE of III/V heterostructures. This technique is not yet widely used, in part because of the scarcity of effusion cell ports in most MBE reactors devoted to device growth. However, as our ability to model (either from first principles or using rate equations) surface dynamics and epitaxial growth increases in sophistication, these kinds of measurements may play an important role in model development and validation. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 15 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD AUG PY 1996 VL 6 IS 2 BP 140 EP 148 DI 10.1016/0927-0256(96)00028-6 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA VJ932 UT WOS:A1996VJ93200006 ER PT J AU Kouzes, RT Meyers, JD Wulf, WA AF Kouzes, RT Meyers, JD Wulf, WA TI Collaboratories: Doing science on the Internet SO COMPUTER LA English DT Article AB The term collaboratory was coined when William Wulf merged ''collaboration'' and ''laboratory'' to describe a ''...center without walls, in which the nation's researchers can perform their research without regard to geographical location-interacting with colleagues, accessing instrumentation, sharing data and computational resources, and accessing information in digital libraries.'' To what degree can we realize this potential? Computer scientists working with domain specialists have made progress on several fronts to facilitate immersive electronic interaction. A new paradigm for intimate collaboration among scientists is thus emerging that will accelerate the development and dissemination of basic knowledge, optimize the use of research instruments, and minimize the time between discovery and application. However, both technical and sociological. challenges remain. A collaboratory is a new, artificial environment that must be socially acceptable to the people who participate, and it must improve their ability to work. Many computing tools must be brought together and integrated to allow seamless interaction. Some of these tools, such as electronic mail and the WWW, are already in wide use, while others, like tele-presence, are still being created. C1 UNIV VIRGINIA, CHARLOTTESVILLE, VA 22903 USA. PACIFIC NW NATL LAB, ENVIRONM MOL SCI LAB, DEPT COMP & INFORMAT SCI, RICHLAND, WA 99352 USA. RP Kouzes, RT (reprint author), W VIRGINIA UNIV, DOE DISTRIBUTED COLABORATORY EXPT ENVIRONM PROJEC, MORGANTOWN, WV 26506 USA. OI Myers, James/0000-0001-8462-650X NR 10 TC 81 Z9 81 U1 0 U2 6 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0018-9162 J9 COMPUTER JI Computer PD AUG PY 1996 VL 29 IS 8 BP 40 EP + DI 10.1109/2.532044 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA VC371 UT WOS:A1996VC37100015 ER PT J AU Sjolander, K Karplus, K Brown, M Hughey, R Krogh, A Mian, IS Haussler, D AF Sjolander, K Karplus, K Brown, M Hughey, R Krogh, A Mian, IS Haussler, D TI Dirichlet mixtures: A method for improved detection of weak but significant protein sequence homology SO COMPUTER APPLICATIONS IN THE BIOSCIENCES LA English DT Article ID ACID SUBSTITUTION MATRICES; STRUCTURAL SIMILARITIES; PROFILE ANALYSIS; ALIGNMENT; DATABASES; BLOCKS; SENSITIVITY; MODELS AB We present a method for condensing the information in multiple alignments of proteins into a mixture of Dirichlet densities over amino acid distributions. Dirichlet mixture densities are designed to be combined with observed amino acid frequencies to form estimates of expected amino acid probabilities at each position in a profile, hidden Mai kov model or other statistical model. These estimates give a statistical model greater generalization capacity, so that remotely related family members can be more reliably recognized by the model. This paper corrects the previously published formula for estimating these expected probabilities, and contains complete derivations of the Dirichlet mixture formulas, methods for optimizing the mixtures to match particular databases, and suggestions for efficient implementation. C1 SANGER CTR, HINXTON CB10 1RQ, CAMBS, ENGLAND. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV LIFE SCI, BERKELEY, CA 94720 USA. RP UNIV CALIF SANTA CRUZ, BASKIN CTR COMP ENGN & INFORMAT SCI, APPL SCI BLDG, SANTA CRUZ, CA 95064 USA. RI Karplus, Kevin/B-8099-2009; Krogh, Anders/M-1541-2014 OI Krogh, Anders/0000-0002-5147-6282 FU NIGMS NIH HHS [GM17129] NR 47 TC 215 Z9 219 U1 0 U2 4 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0266-7061 J9 COMPUT APPL BIOSCI JI Comput. Appl. Biosci. PD AUG PY 1996 VL 12 IS 4 BP 327 EP 345 PG 19 WC Computer Science, Interdisciplinary Applications SC Computer Science GA VM025 UT WOS:A1996VM02500009 PM 8902360 ER PT J AU Choi, J Demmel, J Dhillon, I Dongarra, J Ostrouchov, S Petitet, A Stanley, K Walker, D Whaley, RC AF Choi, J Demmel, J Dhillon, I Dongarra, J Ostrouchov, S Petitet, A Stanley, K Walker, D Whaley, RC TI ScaLAPACK: A portable linear algebra library for distributed memory computers - Design issues and performance SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article; Proceedings Paper CT 10th European Summer School on Computing Techniques in Physics - High Performance Computing in Science CY SEP 05-14, 1995 CL SKALSKY DVUR, CZECH REPUBLIC SP European Phys Soc, Computat Phys Grp, German Phys Soc, Siemens Nixdorf Czech Republic, Westinghouse Elect Corp ID SUBPROGRAMS; SET AB This paper outlines the content and performance of ScaLAPACK, a collection of mathematical software for linear algebra computations on distributed memory computers. The importance of developing standards for computational and message passing interfaces is discussed. We present the different components and building blocks of ScaLAPACK. This paper outlines the difficulties inherent in producing correct codes for networks of heterogeneous processors. We define a theoretical model of parallel computers dedicated to linear algebra applications: the Distributed Linear Algebra Machine (DLAM). This model provides a convenient framework for developing parallel algorithms and investigating their scalability, performance and programmability. Extensive performance results on various platforms are presented and analyzed with the help of the DLAM. Finally, this paper briefly describes future directions for the ScaLAPACK library and concludes by suggesting alternative approaches to mathematical libraries, explaining how ScaLAPACK could be integrated into efficient and user-friendly distributed systems. C1 UNIV CALIF BERKELEY,DIV COMP SCI,BERKELEY,CA 94720. OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. RP Choi, J (reprint author), UNIV TENNESSEE,DEPT COMP SCI,KNOXVILLE,TN 37996, USA. RI Walker, David/B-7978-2010; Whaley, R./G-4234-2011; Dongarra, Jack/E-3987-2014; OI Walker, David/0000-0002-1360-6330 NR 17 TC 66 Z9 66 U1 0 U2 4 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 AUG PY 1996 VL 97 IS 1-2 BP 1 EP 15 DI 10.1016/0010-4655(96)00017-3 PG 15 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA VD453 UT WOS:A1996VD45300003 ER PT J AU Martin, JT AF Martin, JT TI The growing international influence on Fortran standardization SO COMPUTER STANDARDS & INTERFACES LA English DT Article DE international standards; strategic plan; WG5; Fortran 95 AB Fortran was the first programming language to be standardized. That standardization effort was initiated and completed within the United States, resulting in the 1966 standard. Today, standards in the field of information technology are truly international standards. This article describes how Fortran standardization made that transition. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5489 J9 COMP STAND INTER JI Comput. Stand. Interfaces PD AUG PY 1996 VL 18 IS 4 BP 321 EP 322 DI 10.1016/0920-5489(96)01009-4 PG 2 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA VL415 UT WOS:A1996VL41500008 ER PT J AU Stockwell, CA Mulvey, M Vinyard, GL AF Stockwell, CA Mulvey, M Vinyard, GL TI Translocations and the preservation of allelic diversity SO CONSERVATION BIOLOGY LA English DT Article ID MOSQUITOFISH GAMBUSIA-AFFINIS; GENETIC-VARIABILITY; ATLANTIC SALMON; HATCHERY STOCK; BIOCHEMICAL GENETICS; ACRIDOTHERES-TRISTIS; NATURAL-POPULATIONS; BROWN TROUT; CONSERVATION; GROWTH AB Translocation is a tool commonly used for the conservation of threatened and endangered fish species. Despite extensive use, the biological implications of translocation remain poorly understood. Of particular interest is the effect of translocation on genetic variability. Maintenance of genetic variability in these ''refuge'' populations is assumed to be important for both short- and long-term success. We examined allozyme variability at 16 loci for western mosquitofish (Gambusia affinis) populations with known histories of introduction. Refuge populations had significantly lower levels of heterozygosity. Refuge populations also had considerably lower levels of allelic diversity than parental populations. All losses were of relatively rare alleles (frequency less than 0.1 in parental population). These losses were probably due to an undocumented bottleneck early in the introduction history. These results were surprising because the initial transplant involved 900 fish and because mosquitofish have numerous reproductive traits that should minimize the effects of bottlenecks on genetic diversity. A literature review revealed the genetic variability is often reduced in refuge populations and that such reductions typically involve the loss of alleles. We suggest that translocated populations be examined periodically for losses of genetic variability. C1 UNIV NEVADA,DEPT BIOL,BIOL RESOURCES RES CTR,RENO,NV 89557. UNIV NEVADA,PROGRAM ECOL EVOLUT & CONSERVAT BIOL,RENO,NV 89557. RP Stockwell, CA (reprint author), SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 54 TC 75 Z9 78 U1 3 U2 21 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD AUG PY 1996 VL 10 IS 4 BP 1133 EP 1141 DI 10.1046/j.1523-1739.1996.10041133.x PG 9 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA VC103 UT WOS:A1996VC10300030 ER PT J AU Tuberville, TD Gibbons, JW Greene, JL AF Tuberville, TD Gibbons, JW Greene, JL TI Invasion of new aquatic habitats by male freshwater turtles SO COPEIA LA English DT Article ID KINOSTERNON-SUBRUBRUM; PSEUDEMYS-SCRIPTA; SOUTH-CAROLINA; POPULATIONS; MOVEMENT RP Tuberville, TD (reprint author), SAVANNAH RIVER ECOL LAB,PO DRAWER E,AIKEN,SC 29802, USA. NR 20 TC 20 Z9 20 U1 1 U2 4 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS BUSINESS OFFICE PI CARBONDALE PA SOUTHERN ILLINOIS UNIV, DEPT ZOOLOGY, CARBONDALE, IL 62901-6501 SN 0045-8511 J9 COPEIA JI Copeia PD AUG 1 PY 1996 IS 3 BP 713 EP 715 DI 10.2307/1447536 PG 3 WC Zoology SC Zoology GA VB033 UT WOS:A1996VB03300022 ER PT J AU Vaidya, RU Hersman, LE Zurek, AK Butt, DP Laurinavichius, KS Shcherbakova, VA Vishniveckji, SA Golovchenko, NP AF Vaidya, RU Hersman, LE Zurek, AK Butt, DP Laurinavichius, KS Shcherbakova, VA Vishniveckji, SA Golovchenko, NP TI Microbiologically-influenced corrosion of aluminium 6061 and Al2O3 particle-reinforced aluminium 6061 composite under anaerobic conditions and elevated temperatures: The effect on the UTS and strain to failure SO CORROSION PREVENTION & CONTROL LA English DT Article ID METAL MATRIX COMPOSITES; BEHAVIOR; ALLOYS AB MICROBIOLOGICALLY-INFLUENCED corrosion (MIC) of aluminium alloy 6061 and an Al2O3 particle-reinforced 6061 matrix composite was performed under continuous fermentation conditions of several thermophilic, anaerobic, bacteria. The effect of various types of metabolic reactions, several different reduction/oxidation potentials, pH, and temperatures, were also studied. This information was correlated to the rate of corrosion, ultimate tensile strength (UTS), and strain-to-failure of the unreinforced alloy and composite samples. Exposure to thermophilic bacterial species led to a significant decrease in the strain-to-failure of the unreinforced alloy and composite samples. Decrease in the UTS df the alloy and composite samples was bacterial-species specific. Although the temperature and pH of the media did not correlate with specimen corrosion and decreased mechanical properties, reduction in the mechanical properties occurred concurrently with aluminium extraction surface pitting, and nicotinamide adenine dinucleotide reduction/oxidation during the corrosion process. C1 RUSSIAN ACAD SCI,INST BIOCHEM & PHYSIOL MICROORGANISMS,PUSHCHINO 142292,RUSSIA. RP Vaidya, RU (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 29 TC 1 Z9 1 U1 0 U2 2 PU SCIENTIFIC SURVEYS LTD PI BEACONSFIELD PA PO BOX 21, BEACONSFIELD, BUCKS, ENGLAND HP9 1NS SN 0010-9371 J9 CORROS PREVENT CONTR JI Corrosion Prev. Control PD AUG PY 1996 VL 43 IS 4 BP 101 EP & PG 9 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA VL759 UT WOS:A1996VL75900003 ER PT J AU Jeong, S Schultz, JH Takayasu, M Vysotsky, V Michael, PC Warnes, W Shen, S AF Jeong, S Schultz, JH Takayasu, M Vysotsky, V Michael, PC Warnes, W Shen, S TI Ramp-rate limitation experiments using a hybrid superconducting cable SO CRYOGENICS LA English DT Article DE ramp-rate limitation; hybrid cable; cable-in-conduit conductor; pulse coil ID CONDUCTORS AB Ramp-rate limitation experiments were done in a new facility at the MIT (Massachusetts Institute of Technology) Plasma Fusion Center. The features of this new facility include (1) a superconducting pulse coil that can superimpose high ramp-down rates, up to 25 T s(-1), (2 T in 80 ms) at a background field up to 5 T, (2) new power supplies that can supply high rates of dl/dt and dB/dt to the sample under test and (3) a forced-flow supercritical helium system for cooling CICCs (Cable-in-Conduit Conductors). This paper discusses the results of the ramp-rate limitation experiments on a 27-strand hybrid Nb3Sn cable. The cable was tested under field ramps of up to 2.5 T s(-1) with various operating currents. It did not quench with dB/dt, field and average strand currents that were simultaneously above the operating range of TPX-PF (Tokamak Physics Experiment Poloidal Field) coils. Further ramp-rate limitation experiments revealed that the tested 27-strand hybrid cable has very high transient stability at ramped fields, extending out to average strand currents that are nearly triple the TPX-PF operating current. (C) 1996 Elsevier Science Limited C1 MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139. OREGON STATE UNIV,CORVALLIS,OR 97331. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. OI Vysotsky, vysotsky@ieee.org/0000-0003-4947-7072; Michael, Philip/0000-0003-4906-6169 NR 11 TC 13 Z9 13 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD AUG PY 1996 VL 36 IS 8 BP 623 EP 629 DI 10.1016/0011-2275(96)00057-4 PG 7 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA VA512 UT WOS:A1996VA51200009 ER PT J AU Price, DL AF Price, DL TI Intermediate-range order in glasses SO CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE LA English DT Review ID SHARP DIFFRACTION PEAK; NEUTRON-DIFFRACTION; CHALCOGENIDE GLASSES; MOLECULAR-DYNAMICS; VITREOUS SILICA; SIO2; ALLOYS; LIQUID; TEMPERATURE; SIMULATIONS AB Intermediate-range order in glasses exists in different forms in molecular glasses, pure and modified network glasses, and fast ion conducting glasses. Recent work has shown that both intermediate-range order and ionic conductivity in glasses is enhanced by increasing the free volume of the network. RP Price, DL (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Price, David Long/A-8468-2013 NR 55 TC 18 Z9 18 U1 0 U2 1 PU CURRENT SCIENCE LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 1359-0286 J9 CURR OPIN SOLID ST M JI Curr. Opin. Solid State Mat. Sci. PD AUG PY 1996 VL 1 IS 4 BP 572 EP 577 DI 10.1016/S1359-0286(96)80075-1 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA VH554 UT WOS:A1996VH55400017 ER PT J AU Sutherland, JC AF Sutherland, JC TI What's Latin for quintillion? SO DATAMATION LA English DT Letter RP Sutherland, JC (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CAHNERS-DENVER PUBLISHING CO PI HIGHLANDS RANCH PA 8773 S RIDGELINE BLVD, HIGHLANDS RANCH, CO 80126-2329 SN 0011-6963 J9 DATAMATION JI Datamation PD AUG PY 1996 VL 42 IS 14 BP 8 EP 8 PG 1 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA VC223 UT WOS:A1996VC22300006 ER PT J AU Babin, M Morel, A Claustre, H Bricaud, A Kolber, Z Falkowski, PG AF Babin, M Morel, A Claustre, H Bricaud, A Kolber, Z Falkowski, PG TI Nitrogen- and irradiance-dependent variations of the maximum quantum yield of carbon fixation in eutrophic, mesotrophic and oligotrophic marine systems SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID PHOTOSYNTHETIC ENERGY-CONVERSION; CYCLIC ELECTRON FLOW; SPECTRAL ABSORPTION-COEFFICIENTS; ISOCHRYSIS-GALBANA HAPTOPHYCEAE; STEADY-STATE DESCRIPTION; WESTERN NORTH-ATLANTIC; PHOTOSYSTEM-II; PHYTOPLANKTON PHOTOSYNTHESIS; LIGHT UTILIZATION; CHLOROPHYLL CONCENTRATION AB Natural variability of the maximum quantum yield of carbon fixation (phi C-max), as determined from the initial slope of the photosynthesis-irradiance curve and from light absorption measurements, was studied at three sites in the northeast tropical Atlantic representing typical eutrophic, mesotrophic and oligotrophic regimes. At the eutrophic and mesotrophic sites, where the mixed layer extended deeper than the euphotic layer, all photosynthetic parameters were nearly constant with depth, and phi C-max averaged between 0.05 and 0.03 mol C (mel quanta absorbed)(-1), respectively. At the oligotrophic site, a deep chlorophyll maximum (DCM) existed and phi C-max varied from ca 0.005 in the upper nutrient-depleted mixed layer to 0.063 below the DCM in stratified waters. Firstly, phi C-max was found roughly to covary with nitrate concentration between sites and with depth at the oligotrophic site, and secondly, it was found to decrease with increasing relative concentrations of non-photosynthetic pigments. The extent of phi C-max variations directly related to nitrate concentration was inferred from variations in the fraction of functional PS2 reaction centers (f), measured using fast repetition rate fluorometry. Covariations between f and nitrate concentration indicate that the latter factor may be responsible for a 2-fold variation in phi C-max. Moreover, partitioning light absorption between photosynthetic and non-photosynthetic pigments suggests that the variable contribution of the non-photosynthetic absorption may explain a 3-fold variation in phi C-max, as indicated by variations in the effective absorption cross-section of photosystem 2 (sigma(PS2)). Results confirm the role of nitrate in phi C-max variation, and emphasize those of light and vertical mixing. Copyright (C) 1996 Elsevier Science Ltd C1 CNRS, F-06230 VILLEFRANCHE SUR MER, FRANCE. BROOKHAVEN NATL LAB, DIV OCEANOG & ATMOSPHER SCI, UPTON, NY 11973 USA. RP Babin, M (reprint author), UNIV PARIS 06, PHYS & CHIM MARINES LAB, BP 8, F-06230 VILLEFRANCHE SUR MER, FRANCE. RI CLAUSTRE, Herve/E-6877-2011 OI CLAUSTRE, Herve/0000-0001-6243-0258 NR 97 TC 187 Z9 193 U1 0 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD AUG PY 1996 VL 43 IS 8 BP 1241 EP 1272 DI 10.1016/0967-0637(96)00058-1 PG 32 WC Oceanography SC Oceanography GA VU623 UT WOS:A1996VU62300006 ER PT J AU Feng, Z Anders, S Anders, A Ager, JW Brown, IG Komvopoulos, K Bogy, DB AF Feng, Z Anders, S Anders, A Ager, JW Brown, IG Komvopoulos, K Bogy, DB TI Diamond growth on hard carbon films SO DIAMOND AND RELATED MATERIALS LA English DT Article DE diamond-like carbon (dlc) pretreatment; diamond nucleation; CVD diamond growth; pretreatment ID CHEMICAL-VAPOR-DEPOSITION; THIN-FILMS; NUCLEATION; SILICON; DENSITY; VACUUM; BEAMS AB A three-step process for enhancing the nucleation density of diamond on unscratched silicon substrates using microwave-plasma-enhanced chemical vapor deposition is described. Hard diamond-like carbon (die) films with thickness in the range 5-100 nm were first formed on smooth (100) silicon surfaces using a vacuum-are plasma deposition technique at room temperature. The dlc-coated silicon substrates were subsequently subjected to a low-temperature pretreatment with a methane-rich plasma for an hour before switching to the diamond nucleation conditions. To investigate the effect of the die film structure on diamond nucleation, experiments with silicon substrates coated with evaporated carbon films approximately 50-100 MI thick were also performed under similar pretreatment and diamond nucleation conditions. Diamond films with nucleation density about 2 x 10(8) cm(-2) were obtained with pretreated die films, depending on the film thickness and the pretreatment time, whereas in the absence of the pretreatment and/or with evaporated carbon films the diamond nucleation density was less than 10(4)cm(-2). The significant enhancement in diamond nucleation density obtained with pretreated die films is attributed to the inherently high etching resistance of the films resulting from the high fraction of sp(3) bonds. The actual nucleation sites might be very fine carbon or, possibly, SiC particles produced by etching back the die film. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT ENGN MECH,BERKELEY,CA 94720. RI Anders, Andre/B-8580-2009; Raoux, Simone/G-3920-2016; OI Anders, Andre/0000-0002-5313-6505; Ager, Joel/0000-0001-9334-9751 NR 20 TC 4 Z9 4 U1 1 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD AUG PY 1996 VL 5 IS 10 BP 1080 EP 1086 DI 10.1016/0925-9635(96)00518-3 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA VH527 UT WOS:A1996VH52700004 ER PT J AU Gratz, AJ Fisler, DK Bohor, BF AF Gratz, AJ Fisler, DK Bohor, BF TI Distinguishing shocked from tectonically deformed quartz by the use of the SEM and chemical etching SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE scanning electron microscopy; etching; quartz; deformation; shock metamorphism ID CRETACEOUS-TERTIARY BOUNDARY; VOLCANIC EJECTA; TOBA CALDERA; DYNAMIC DEFORMATION; POSSIBLE RELEVANCE; METAMORPHISM; SITE AB Multiple sets of crystallographically-oriented planar deformation features (PDFs) are generated by high-strain-rate shock waves at pressures of > 12 GPa in naturally shocked quartz samples. On surfaces, PDFs appear as narrow (50-500 nm) lamellae filled with amorphosed quartz (diaplectic glass) which can be etched with hydrofluoric acid or with hydrothermal alkaline solutions. In contrast, slow-strain-rate tectonic deformation pressure produces wider, semi-linear and widely spaced arrays of dislocation loops that are not glass filled. Etching samples with HF before examination in a scanning electron microscope (SEM) allows for unambiguous visual distinction between glass-filled PDFs and glass-free tectonic deformation arrays in quartz. This etching also reveals the internal 'pillaring' often characteristic of shock-induced PDFs. This technique is useful for easily distinguishing between shock and tectonic deformation in quartz, but does not replace optical techniques for characterizing the shock features. C1 SANDIA NATL LABS,DEPT GEOCHEM,ALBUQUERQUE,NM 87123. LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. US GEOL SURVEY,DENVER,CO 80225. NR 33 TC 24 Z9 24 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 PY 1996 VL 142 IS 3-4 BP 513 EP 521 DI 10.1016/0012-821X(96)00099-4 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VG528 UT WOS:A1996VG52800017 ER PT J AU Loehle, C Li, BL AF Loehle, C Li, BL TI Habitat destruction and the extinction debt revisited SO ECOLOGICAL APPLICATIONS LA English DT Article DE endangered species; extinction-debt model; extinction theory; habitat fragmentation; landscapes; spatial scale, importance of; species-area curve ID COMPETITIVE COEXISTENCE; METAPOPULATION DYNAMICS; MODEL; PLANTS AB A very important published analysis of the problem of habitat destruction (Tilman et al. 1994 [Nature 371:65-66]) concluded that such destruction may lead to an extinction debt, which is the irreversible, preferential loss of competitive species following a prolonged transient or delay after the habitat destruction. We analyzed this model using analytic and simulation techniques. Relating this analytic model to real-world situations shows that it applies to scattered permanent devegetation of small patches and to across-the-board decreases in fecundity such as could be caused by pollution. For repeated spatially random disturbance, we develop a new model that shows an even more severe extinction-debt effect. For larger fragments of remnant vegetation, such as forest woodlots, we argue that the assumptions of-the model are violated but that an extinction debt nevertheless occurs due to gradual stochastic elimination of species that are very rare and isolated in these fragments. For habitat destruction on regional scales (reduction in ecosystem area without disturbance in remnant areas), one must, in contrast, apply species-area relations based on the distribution of-different habitat types (e.g., elevational and rainfall gradients, physiographic and edaphic variability). Such an analysis predicts rapid, not delayed, loss of all types of species, not just competitive types. We conclude that the extinction-debt effect is real and arises in three different models, but relating the models to real-world conservation problems must be done with care. C1 TEXAS A&M UNIV,DEPT IND ENGN,CTR BIOSYST MODELLING,COLLEGE STN,TX 77843. RP Loehle, C (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 27 TC 72 Z9 83 U1 5 U2 44 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 1996 VL 6 IS 3 BP 784 EP 789 DI 10.2307/2269483 PG 6 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UZ412 UT WOS:A1996UZ41200024 ER PT J AU Townsend, AR Braswell, BH Holland, EA Penner, JE AF Townsend, AR Braswell, BH Holland, EA Penner, JE TI Spatial and temporal patterns in terrestrial carbon storage due to deposition of fossil fuel nitrogen SO ECOLOGICAL APPLICATIONS LA English DT Article DE atmospheric chemistry; cultivation; forest carbon; global carbon cycle; N limitation; NOy deposition ID FOREST ECOSYSTEMS; ATMOSPHERIC CARBON; LATITUDINAL DISTRIBUTION; SOILS; CO2; CULTIVATION; POLLUTION; BIOSPHERE; CLIMATE; DIOXIDE AB Fertilization of the biosphere by nitrogen deposition represents an important connection between atmospheric chemistry and the global carbon cycle. We describe a modeled estimate of terrestrial carbon storage arising from deposition of nitrogen derived from fossil fuels that accounts for spatial distributions in deposition and vegetation types, turnover of plant and soil carbon pools, and the cumulative effects of deposition, Vegetation type has a pronounced effect on C uptake; the combination of high C:N ratios and long lifetimes in wood may create a significant sink in forests, but much of the nitrogen falls on cultivated areas and grasslands, where there is limited capacity for long-term carbon storage. We estimate 1990 net carbon uptake due to deposition of fossil-fuel N to be between 0.3 and 1.3 Pg C/yr [1 Pg = 10(15) g], depending on the fraction of C allocated to wood, with a best estimate of 0.44-0.74 Pg/yr. Cumulative C storage since 1845 is estimated to be about 25% of the proposed terrestrial sink for anthropogenic CO2. Continued exposure to high N deposition, however, will decrease the extent of N limitation in terrestrial ecosystems, thereby limiting the persistence of any N-derived carbon sink. C1 NATL CTR ATMOSPHER RES,DIV ATMOSPHER CHEM,BOULDER,CO 80307. UNIV NEW HAMPSHIRE,COMPLEX SYST RES CTR,DURHAM,NH 03824. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RI Penner, Joyce/J-1719-2012; Braswell, Bobby/D-6411-2016 OI Braswell, Bobby/0000-0002-4061-9516 NR 47 TC 255 Z9 295 U1 6 U2 75 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 1996 VL 6 IS 3 BP 806 EP 814 DI 10.2307/2269486 PG 9 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UZ412 UT WOS:A1996UZ41200027 ER PT J AU Li, J Janata, J Josowicz, M AF Li, J Janata, J Josowicz, M TI Application of poly(cyclophosphazene) for potentiometric detection of tributyl phosphate vapor SO ELECTROANALYSIS LA English DT Article DE tributyl phosphate; work function; gas sensor; charge-transfer; poly(cyclophosphazene) AB Potentiometric sensing layer for detection of tributyl phosphate (TBP) in the concentration range from 1.1 ppb up to 8.8 ppm is described. The high sensitivity to TBP is based on a specific charge-transfer interaction that occurs between iodine species and the oxygen atom of the phosphoryl group of TBP. Thr iodine is incorporated electrochemically or chemically into a chemically inert poly(cyclophosphazene-benzoquinone), PPBQ, matrix. The bulk involvement of the new material in the interaction with the TBP vapor leads to modulation of its Fermi level. The number of moles of charge shared bq the TBP with the sensitive layer is between 0.8 to 0.9 in the range of concentrations between 0.27 and 8.8 ppm. The interaction is highly reversible and reproducible. RP Li, J (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LABS, POB 999, RICHLAND, WA 99352 USA. NR 15 TC 10 Z9 11 U1 0 U2 1 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD AUG-SEP PY 1996 VL 8 IS 8-9 BP 778 EP 783 DI 10.1002/elan.1140080814 PG 6 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA VL038 UT WOS:A1996VL03800013 ER PT J AU Woodward, LA Mulvey, M Newman, MC AF Woodward, LA Mulvey, M Newman, MC TI Mercury contamination and population-level responses in chironomids: Can allozyme polymorphism indicate exposure? SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE allozyme; mercury; chironomids; Wahlund effect; population genetics ID GAMBUSIA-AFFINIS BAIRD; INORGANIC MERCURY; NATURAL POPULATIONS; MARINE ORGANISMS; MOSQUITOFISH; SELECTION; POLLUTION; GENOTYPE; CADMIUM; DEATH AB Allozyme frequencies of Chironomus plumosus were determined along a gradient of sediment mercury concentrations in a contaminated lake. We examined whether allozyme frequencies could be used to distinguish populations along the gradient or between contaminated and reference sites. No significant correlations were found between allozyme frequencies and contamination, but an overall deficit of heterozygotes (in nine of 13 loci examined) was found at all sites sampled. While toxicant stress could be the cause, a more parsimonious explanation would be sampling over a patchy population structure leading to a heterozygote deficiency (i.e., Wahlund effect). Examination of allozyme frequencies along a transect indicated that the observed deficiency of heterozygote genotypes was due to sampling across some fine-scale substructuring of the populations. The findings of these studies lend a note of caution regarding the use of allozymes to infer population effects of contaminants or their potential use as biomarkers. Studies must define population structure, naturally occurring variation within and among populations, and relevant ecological factors in conjunction with the presence of xenobiotics and their concentrations. C1 UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, AIKEN, SC 29802 USA. RP Woodward, LA (reprint author), UNIV CALIF DAVIS, DAVIS, CA 95616 USA. NR 28 TC 11 Z9 11 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0730-7268 EI 1552-8618 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD AUG PY 1996 VL 15 IS 8 BP 1309 EP 1316 DI 10.1897/1551-5028(1996)015<1309:MCAPLR>2.3.CO;2 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA VF371 UT WOS:A1996VF37100008 ER PT J AU Inoue, T Cronkite, EP Hirabayashi, Y Yoshida, K Bullis, JF Umemura, T AF Inoue, T Cronkite, EP Hirabayashi, Y Yoshida, K Bullis, JF Umemura, T TI Myelodysplasia after life-time treatment of azidothymidine (AZT)-implication of histopathological details and stem cell kinetics SO EXPERIMENTAL HEMATOLOGY LA English DT Meeting Abstract C1 NATL INST HLTH SCI,CELL & MOL TOXICOL DIV,TOKYO,JAPAN. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. NATL INST RADIOL SCI,DIV BIOL & ONCOL,CHIBA,JAPAN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CARDEN JENNINGS PUBL CO LTD PI CHARLOTTESVILLE PA BLAKE CTR, STE 200, 1224 W MAIN ST, CHARLOTTESVILLE, VA 22903 SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD AUG PY 1996 VL 24 IS 9 BP 71 EP 71 PG 1 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA VC092 UT WOS:A1996VC09200071 ER PT J AU Nilsson, SK Dooner, MS Tiarks, CY Weier, HUG Quesenberry, PJ AF Nilsson, SK Dooner, MS Tiarks, CY Weier, HUG Quesenberry, PJ TI Homing of primitive stem cells into the marrow of nonablated murine hosts. SO EXPERIMENTAL HEMATOLOGY LA English DT Meeting Abstract C1 UNIV MASSACHUSETTS,MED CTR,CTR CANC,WORCESTER,MA. LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA. RI Nilsson, Susie/C-5563-2015 OI Nilsson, Susie/0000-0002-7926-7335 NR 0 TC 0 Z9 0 U1 0 U2 0 PU CARDEN JENNINGS PUBL CO LTD PI CHARLOTTESVILLE PA BLAKE CTR, STE 200, 1224 W MAIN ST, CHARLOTTESVILLE, VA 22903 SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD AUG PY 1996 VL 24 IS 9 BP 81 EP 81 PG 1 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA VC092 UT WOS:A1996VC09200081 ER PT J AU PavlovicKentera, V Lezaic, V Clemons, G Djukanovic, L AF PavlovicKentera, V Lezaic, V Clemons, G Djukanovic, L TI Serum erythropoietin levels after renal transplantation: Ratio between observed to expected values. SO EXPERIMENTAL HEMATOLOGY LA English DT Meeting Abstract C1 INST MED RES,BELGRADE,YUGOSLAVIA. INST UROL & NEPHROL,BELGRADE,YUGOSLAVIA. LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CARDEN JENNINGS PUBL CO LTD PI CHARLOTTESVILLE PA BLAKE CTR, STE 200, 1224 W MAIN ST, CHARLOTTESVILLE, VA 22903 SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD AUG PY 1996 VL 24 IS 9 BP 217 EP 217 PG 1 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA VC092 UT WOS:A1996VC09200216 ER PT J AU Breneman, JW Briner, JF Ramsey, MJ Director, A Tucker, JD AF Breneman, JW Briner, JF Ramsey, MJ Director, A Tucker, JD TI Cytogenetic results from a chronic feeding study of MeIQx in mice SO FOOD AND CHEMICAL TOXICOLOGY LA English DT Article ID COOKED FOOD MUTAGENS; RADIATION IN-VITRO; HETEROCYCLIC AMINES; 2-AMINO-3,8-DIMETHYLIMIDAZO<4,5-F>QUINOXALINE MEIQX; ARYLNITRENIUM IONS; MOUSE; CARCINOGENICITY; DNA; IQ; METABOLISM AB The primary food mutagens found in cooked meat are the heterocyclic aromatic amines, including 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx). High dose, acute exposures of MeIQx produce hepatic tumours in some mouse and rat strains. By assaying chromosome damage it may be possible to correlate aberrations with exposure to a mutagen. Whole chromosome painting by fluorescence in situ hybridization allows the rapid screening of metaphase chromosomes for rearrangements. This technique was applied to female mice (C57BL/6) chronically fed 100-400 ppm MeIQx for up to 6 months. Two tissues, blood and bone marrow, were screened with multicolour whole chromosome painting probes (1, 2, 3 and 8). The mice showed no outward signs of toxicity at any dose and very few chromosome aberrations were observed. A slight but significant increase in sister chromatid exchanges (SCE) was seen at 400 ppm in blood at 6 months. When MeIQx was removed from the diet for 1 month there was an apparent decline in SCEs only for animals previously given the 400 ppm diet. Published by Elsevier Science Ltd C1 LAWRENCE LIVERMORE NATL LAB, BIOL & BIOTECHNOL RES PROGRAM, LIVERMORE, CA 94551 USA. W VIRGINIA UNIV, COLL AGR & FORESTRY, DIV PLANT & SOIL SCI, MORGANTOWN, WV 26506 USA. FU NCI NIH HHS [CA55861] NR 37 TC 11 Z9 11 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0278-6915 J9 FOOD CHEM TOXICOL JI Food Chem. Toxicol. PD AUG PY 1996 VL 34 IS 8 BP 717 EP 724 DI 10.1016/0278-6915(96)00043-9 PG 8 WC Food Science & Technology; Toxicology SC Food Science & Technology; Toxicology GA VP412 UT WOS:A1996VP41200007 PM 8883473 ER PT J AU Wilmot, TR Ellsworth, DS Tyree, MT AF Wilmot, TR Ellsworth, DS Tyree, MT TI Base cation fertilization and liming effects on nutrition and growth of Vermont sugar maple stands SO FOREST ECOLOGY AND MANAGEMENT LA English DT Article DE Acer saccharum; calcium; forest fertilization; nutrients; potassium; tree growth ID FOLIAR NUTRIENT STATUS; QUEBEC APPALACHIANS; SOUTHEASTERN QUEBEC; LOWER LAURENTIANS; NORTHERN VERMONT; CROWN CONDITION; FOREST DECLINE; SOIL; CHEMISTRY; DIEBACK AB Soil and foliar nutrition, crown condition, and wood growth were measured in three mature sugar maple stands in northern Vermont before and after fertilization with base cations (107 kg ha(-1) K, 53 kg ha(-1) Ca and 11 kg ha(-1) Mg) with or without 3000 kg ha(-1) supplemental lime in order to test the effectiveness of such treatments in ameliorating base cation deficiencies in sugar maple (Acer saccharum Marsh.). Pre-fertilization analyses indicated multiple cation deficiencies in these stands, since foliar K, Ca and Mg were all near or below sufficiency standards suggested for sugar maple, Fertilization with cations in addition to liming elevated soil pH from 3.6 to 4.5 in the first year after treatment, and elevated soil pH was maintained over two additional growing seasons along with significantly improved soil Ca and decreased soil Al. Foliar K, Ca and P concentrations were all significantly improved (P < 0.05) compared with controls for the three growing seasons following the first treatment, while only foliar K concentration showed significant improvement in plots treated with the base cation fertilizer without lime. By the third growing season following treatment, trees in limed plots had significantly less crown dieback than controls or trees in plots treated with the base cation fertilizer alone. Diameter growth showed marginal improvement in the plots treated with cations, annual. diameter growth increased 200% compared with controls in the limed plots, Despite these positive results, the long term contribution of increased soil pH and soil calcium to soil nutrient pools and root distribution remains to be determined, as does the sustainability of growth increases, We conclude that in northern Vermont sugar maple stands on relatively infertile podzols with low pH, base cation limitations may be especially important in controlling sugar maple tree health or growth, while fertilization to ameliorate base cation deficiencies may be effective only at relatively high base cation addition rates. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,BIOSYST & PROC SCI DIV,UPTON,NY 11973. UNIV VERMONT,PROCTOR MAPLE RES CTR,UNDERHILL CTR,VT 05490. US FOREST SERV,NE FOREST EXPT STN,BURLINGTON,VT 05402. OI Ellsworth, David/0000-0002-9699-2272 NR 35 TC 53 Z9 55 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1127 J9 FOREST ECOL MANAG JI For. Ecol. Manage. PD AUG PY 1996 VL 84 IS 1-3 BP 123 EP 134 DI 10.1016/0378-1127(96)03743-7 PG 12 WC Forestry SC Forestry GA VH048 UT WOS:A1996VH04800011 ER PT J AU Brannan, CJ Curtis, CW Cronauer, DC AF Brannan, CJ Curtis, CW Cronauer, DC TI Effect of solvent swelling and catalyst impregnation on the liquefaction of Black Thunder coal SO FUEL PROCESSING TECHNOLOGY LA English DT Article DE swelling solvents; liquefaction ID MACROMOLECULAR STRUCTURE; SWOLLEN COALS; BENEFICIATION; PRETREATMENT; BEHAVIOR AB The effect of swelling untreated and SO2-treated Black Thunder coals on coal liquefaction behavior was investigated. Catalyst precursors including Molyvan L, molybdenum naphthenate, and nickel octoate were introduced into swelling solvents consisting of tetrahydrofuran (THF), isopropanol, or methanol at typical loadings of 700 ppm of active metal. Coal liquefaction reactions were performed at 385 and 410 degrees C using 1-methylnaphthalene, dihydroanthracene, or coal-derived V1074 as liquefaction solvents. The efficacy of the process was measured by using coal conversion to THF-soluble materials. Pyrene was added to the liquefaction feed to provide a measure of catalyst hydrogenation activity. Swelling of coal in the presence of a catalyst prior to liquefaction should increase the accessibility of the interstitial structure to the catalyst and, therefore, increase coal reactivity at liquefaction conditions; however, this concept was valid with only one catalyst system. Only the addition of molybdenum naphthenate with added excess sulfur resulted in improved conversion of Black Thunder (WY sub-bituminous) coal. No improvement with the addition of either Molyvan L or nicker octoate was observed. The addition of all of the catalyst precursors resulted in increased pyrene hydrogenation; therefore, there was not a direct correlation of hydrogenation and coal conversion catalytic activities. C1 AUBURN UNIV,DEPT CHEM ENGN,AUBURN,AL 36849. ARGONNE NATL LAB,CHM 200,ARGONNE,IL 60439. NR 27 TC 8 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD AUG PY 1996 VL 48 IS 2 BP 173 EP 187 DI 10.1016/S0378-3820(96)01035-1 PG 15 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA VU559 UT WOS:A1996VU55900006 ER PT J AU Bartels, HW Cheng, E Gaeta, M Merrill, B Petti, D AF Bartels, HW Cheng, E Gaeta, M Merrill, B Petti, D TI Decay heat removal in the ITER outline design SO FUSION ENGINEERING AND DESIGN LA English DT Article AB Decay heat densities are fairly small in ITER when compared to fission plants. The global decay heat in the water cooled shielding blanket design of ITER (fusion power 1.5 GW) is about 20 MW at shutdown and decreases to 1.5 MW after one day after which it stays fairly constant (1 MW after one month). These numbers are calculated assuming pulsed operation of ITER. With active blanket cooling in operation the removal of this decay heat does not pose any problem. Active vacuum vessel cooling alone can limit in-vessel temperatures to below 500 degrees C which is required to limit H-2 production from long-term Be-steam reactions. Several strategies to deal with decay heat in situations ranging from normal operation to beyond design basis accidents (occurrence rate of event sequence < 10(-6) per yr) are analyzed. In beyond design basis states it is important to access the heat sink of the magnets and/or cryostat. To promote passive decay heat removal one has to optimize the radial thermal conductivity through blanket and radiation transport between the blanket and vacuum vessel. C1 TSI RES INC,SOLANA BEACH,CA 92075. IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. RP Bartels, HW (reprint author), ITER SAN DIEGO JWS,11025 N TORREY PINES RD,LA JOLLA,CA 92037, USA. NR 24 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD AUG PY 1996 VL 31 IS 3 BP 203 EP 219 DI 10.1016/0920-3796(96)00523-6 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VF265 UT WOS:A1996VF26500001 ER PT J AU Smith, DL Ikeda, Y Uno, Y AF Smith, DL Ikeda, Y Uno, Y TI An investigation into the possibility of performing radiography with gamma rays emitted from water made radioactive by irradiation with 14 MeV D-T fusion neutrons (vol 31, pg 41, 1996) SO FUSION ENGINEERING AND DESIGN LA English DT Correction, Addition C1 JAPAN ATOM ENERGY RES INST,DEPT REACTOR ENGN,FUS NEUTRON LAB,TOKAI,IBARAKI 31911,JAPAN. RP Smith, DL (reprint author), ARGONNE NATL LAB,TECHNOL DEV DIV,ARGONNE,IL 60439, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD AUG PY 1996 VL 31 IS 4 BP 333 EP 333 PG 1 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VK254 UT WOS:A1996VK25400006 ER PT J AU Holst, LS Langin, D Mulder, H Laurell, H Grober, J Bergh, A Mohrenweiser, HW Edgren, G Holm, C AF Holst, LS Langin, D Mulder, H Laurell, H Grober, J Bergh, A Mohrenweiser, HW Edgren, G Holm, C TI Molecular cloning, genomic organization, and expression of a testicular isoform of hormone-sensitive lipase SO GENOMICS LA English DT Article ID CHOLESTEROL ESTER HYDROLASE; SALT-STIMULATED LIPASE; ADIPOSE-TISSUE; GENE-EXPRESSION; CDNA CLONING; RAT; SEQUENCE; CELLS; PURIFICATION; LOCALIZATION AB By catalyzing the rate-limiting step in adipose tissue lipolysis, hormone sensitive lipase (HSL) is an important regulator of energy homeostasis. The role and importance of HSL in tissues other than adipose are poorly understood. We report here the cloning and expression of a testicular isoform, designated HSL(tes). Due to an addition of amino acids at the NH2-termini, rat and human HSL(tes) consist of 1068 and 1076 amino acids, respectively, compared to the 768 and 775 amino acids, respectively, of the adipocyte isoform (HSL(adi)). A novel exon of 1.2 kb, encoding the human testis-specific amino acids, was isolated and mapped to the HSL gene, 16 kb upstream of the exons encoding HSL(adi). The transcribed mRNA of 3.9 kb was specifically expressed in testis. No significant similarity with other known proteins was found for the testis-specific sequence. The amino acid composition differs from the HSL(adi) sequence, with a notable hydrophilic character and a high content of prolines and glutamines. COS cells, transfected by the 3.9-kb human testis cDNA, expressed a protein of the expected molecular mass (M(r) approximate to 120,000) that exhibited catalytic activity similar to that of HSL(adi). Immunocytochemistry localized HSL to elongating spermatids and spermatozoa; HSL was not detected in interstitial cells. (C) 1996 Academic Press, Inc. C1 UNIV TOULOUSE 3,FAC MED,INST LOUIS BUGNARD,F-31062 TOULOUSE,FRANCE. LUND UNIV,DEPT PHYSIOL SCI,S-22100 LUND,SWEDEN. UMEA UNIV,DEPT PATHOL,S-90187 UMEA,SWEDEN. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. LUND UNIV,DEPT MOL & CELL BIOL,SECT CELL & MATRIX BIOL,S-22100 LUND,SWEDEN. RP Holst, LS (reprint author), LUND UNIV,DEPT MOL & CELL BIOL,SECT MOL SIGNALLING,POB 94,S-22100 LUND,SWEDEN. RI Mulder, Hindrik/E-1045-2012 NR 34 TC 70 Z9 77 U1 0 U2 6 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD AUG 1 PY 1996 VL 35 IS 3 BP 441 EP 447 PG 7 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA VB758 UT WOS:A1996VB75800005 PM 8812477 ER PT J AU Stubbs, L Carver, EA Shannon, ME Kim, J Geisler, J Generoso, EE Stanford, BG Dunn, WC Mohrenweiser, H Zimmermann, W Watt, SM Ashworth, LK AF Stubbs, L Carver, EA Shannon, ME Kim, J Geisler, J Generoso, EE Stanford, BG Dunn, WC Mohrenweiser, H Zimmermann, W Watt, SM Ashworth, LK TI Detailed comparative map of human chromosome 19q and related regions of the mouse genome SO GENOMICS LA English DT Article ID EXPRESSED SEQUENCE TAGS; SITU HYBRIDIZATION MAP; GENETIC-LINKAGE MAP; CDNA CLONING; MOLECULAR-CLONING; GROWTH-FACTOR; T-COMPLEX; SARCOPLASMIC-RETICULUM; HIGH-RESOLUTION; MURINE HOMOLOG AB One of the larger contiguous blocks of mouse-human genomic homology includes the proximal portion of mouse chromosome 7 and the long arm of human chromosome 19. Previous studies have demonstrated the close relationship between the two regions, but have also indicated significant rearrangements in the relative orders of homologous mouse and human genes. Here we present the genetic locations of the homologs of 42 human chromosome 19q markers in the mouse, with an emphasis on genes also included in the human chromosome 19 physical map. Our results demonstrate that despite an overall inversion of sequences relative to the centromere, apparent ''transpositions'' of three gene-rich segments, and a local inversion of markers mapping near the 19q telomere, gene content, order, and spacing are remarkably well conserved throughout the lengths of these related mouse and human regions. Although most human 19q markers have remained genetically linked in mouse, one small human segment forms a separate region of homology between human chromosome 19q and mouse chromosome 17. Three of the four rearrangements of mouse versus human 19q sequences involve segments that are located directly adjacent to each other in 19q13.3-q13.4, suggesting either the coincident occurrence of these events or their common association with unstable DNA sequences. These data permit an unusually in-depth examination of this large region of mouse-human genomic homology and provide an important new tool to aid in the mapping of genes and associated phenotypes in both species. (C) 1996 Academic Press, Inc. C1 UNIV TENNESSEE,OAK RIDGE SCH BIOMED SCI,OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA 94551. UNIV FREIBURG,INST IMMUNOBIOL,D-79104 FREIBURG,GERMANY. JOHN RADCLIFFE HOSP,INST MOL MED,MRC,MOL HAEMATOL UNIT,OXFORD OX3 9DU,ENGLAND. RP Stubbs, L (reprint author), OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37831, USA. OI Stubbs, Lisa/0000-0002-9556-1972 NR 66 TC 71 Z9 71 U1 1 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD AUG 1 PY 1996 VL 35 IS 3 BP 499 EP 508 DI 10.1006/geno.1996.0390 PG 10 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA VB758 UT WOS:A1996VB75800012 PM 8812484 ER PT J AU Davisson, ML Criss, RE AF Davisson, ML Criss, RE TI Na-Ca-Cl relations in basinal fluids SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID TECTONICALLY EXPELLED FLUIDS; SALINE FORMATION WATERS; NORTHERN COAST RANGES; MICHIGAN BASIN; FRIO FORMATION; CHEMICAL EVOLUTION; SEDIMENTARY BASIN; ISOTOPE CHEMISTRY; ROCK INTERACTION; PERMIAN HALITE AB A new mathematical transformation of Na, Ca, and Cl concentrations in numerous basinal fluids around the world produces a linear slope of unity between the milliequivalencies of Na and Ca cations. The transformation entails a simple milliequivalent comparison between the excess Ca and the Na deficit relative to seawater reference ratios. The relevant parameters are: Ca-excess = [Ca-meas - (Ca/Cl)(sw) Cl-meas] 2/40.08, Na-deficit = [(Na/Cl)(sw) Cl-meas - Na-meas] 1/22.99, where the concentrations (in mg/L) of the ions measured (meas) in a sample are referred to those in seawater (sw), and the numerical constants convert the results to meq/L. For >800 samples from numerous fluid reservoirs, with Cl concentrations that range from approximately 1-300 g/L and host lithologies from carbonates to granites, a highly correlated regression termed the Basinal Fluid Line (BFL) is found: Ca-excess = 0.967 (Na-deficit) + 140.3 R = 0.981 The unit slope of the BFL indicates a net cation exchange ratio of 2 Na for 1 Ca. The excess-deficit parameters show no correlation to Mg or K. If a single predominating reaction is presumed to control the BFL, only albitization of plagioclase by 2 Na for 1 Ca exchange is plausible. The BFL offers no support for a predominating reaction involving the 1:1 exchange of Na for Ca that has also been proposed for albitization reactions, nor for the hypothesis that dolomitization produces the elevated Ca contents of basinal fluids. The BFL may incorporate the effects of other water-rock reactions provided that they involve a net exchange of 2 Na for 1 Ca in sedimentary basins. The small y-intercept of 140.3 of the BFL is generally consistent with an origination of the brines from seawater, which would plot at the origin of an excess-deficit graph, However, for regressions derived for fluids from individual basins, the y-intercepts increase with increasing salinity of their fluids, consistent with model predictions for dissolution of halite into either a seawater or freshwater parent, followed by 2 Na for 1 Ca exchange. Because the hydrosphere is dominated by seawater and the upper crust by feldspar minerals, the BFL arguably represents the overall product of cation exchange of high salinity fluids in deep continental environments. C1 WASHINGTON UNIV,DEPT EARTH & PLANETARY SCI,ST LOUIS,MO 63130. RP Davisson, ML (reprint author), LAWRENCE LIVERMORE NATL LAB,ISOTOPE SCI DIV,POB 808 L-231,LIVERMORE,CA 94550, USA. NR 63 TC 71 Z9 89 U1 1 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 1996 VL 60 IS 15 BP 2743 EP 2752 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VC088 UT WOS:A1996VC08800002 ER PT J AU Gu, BH Mehlhorn, TL Liang, LY McCarthy, JF AF Gu, BH Mehlhorn, TL Liang, LY McCarthy, JF TI Competitive adsorption, displacement, and transport of organic matter on iron oxide .2. Displacement and transport SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID CARBOXYL-GROUP STRUCTURES; HUMIC SUBSTANCES; AQUIFER MATERIAL; WATER INTERFACE; SUWANNEE RIVER; SANDY AQUIFER; FULVIC-ACID; COLUMNS; MODELS; RETENTION AB The competitive interactions between organic matter compounds and mineral surfaces are poorly understood, yet these interactions may play a significant role in the stability and co-transport of mineral colloids and/or environmental contaminants. In this study, the processes of competitive adsorption, displacement, and transport of Suwannee River natural organic matter (SR-NOM) are investigated with several model organic compounds in packed beds of iron oxide-coated quartz columns. Results demonstrated that strongly-binding organic compounds are competitively adsorbed and displace those weakly-bound organic compounds along the flow path. Among the four organic compounds studied, polyacrylic acid (PAA) appeared to be the most competitive, whereas SR-NOM was more competitive than phthalic and salicylic acids. The transport of SR-NOM is found to involve a complex competitive interaction and displacement of different NOM subcomponents. A diffuse adsorption and sharp desorption front (giving an appearance of irreversible adsorption) of the SR-NOM breakthrough curves are explained as being a result of the competitive time-dependent adsorption and displacement processes between different organic components within the SR-NOM. The stability and transport of iron oxide colloids varied as one organic component competitively displaces another. Relatively large quantities of iron oxide colloids are transported when the more strongly-binding PAA competitively displaces the weakly-binding SR-NOM or when SR-NOM competitively displaces phthalic and salicylic acids. Results of this study suggest that the chemical composition and hence the functional behavior of NOM (e.g., in stabilizing mineral colloids and in complexing contaminants) can change along its flow path as a result of the dynamic competitive interactions between heterogeneous NOM subcomponents. Further studies are needed to better define and quantify these NOM components as well as their roles in contaminant partitioning and transport. RP Gu, BH (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Gu, Baohua/B-9511-2012; Liang, Liyuan/O-7213-2014 OI Gu, Baohua/0000-0002-7299-2956; Liang, Liyuan/0000-0003-1338-0324 NR 39 TC 59 Z9 63 U1 0 U2 29 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 1996 VL 60 IS 16 BP 2977 EP 2992 DI 10.1016/0016-7037(96)00157-3 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VC980 UT WOS:A1996VC98000004 ER PT J AU Farges, F Brown, GE Rehr, JJ AF Farges, F Brown, GE Rehr, JJ TI Coordination chemistry of Ti(IV) in silicate glasses and melts .1. XAFS study of titanium coordination in oxide model compounds SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Review ID X-RAY-ABSORPTION; MULTIPLE-SCATTERING CALCULATIONS; NEAR-EDGE STRUCTURE; CRYSTAL-STRUCTURE; TI; SPECTRA; XANES; SYSTEM; SPECTROSCOPY; EXAFS AB The coordination environment of Ti(IV) in a variety of Ti-bearing crystalline oxide and silicate model compounds has been studied using Ti K-edge x-ray absorption fine structure (XAFS) spectroscopy at ambient temperature and pressure in order to provide a quantitative basis for interpreting Ti K-edge XAFS spectra of silicate glasses and melts (Parts II, III, and IV: Farges and Brown, 1996; Farges et al., 1996a,b). Pre-edge features of Ti K-edge XAFS spectra can be used to derive. accurate information on the local coordination environment of Ti only if both pre-edge position and heights are considered. Using these features, it is also possible to distinguish between one coordination environment vs. a mixture of several others (e.g., Ti-[5] vs. Ti-[4] + Ti-[6]). Quantitative analysis of the Ti x-ray absorption near edge structure (XANES) spectra, based on abinitio multiple-scattering calculations for a variety of Ti-containing clusters and anharmonic analysis of the normalized XAFS oscillations. show that O first neighbors and alkali/alkaline-earth second neighbors around Ti contribute to the XAFS spectra. However, second neighbors are more prominent in the XANES region because the effects of disorder associated with these contributions are less important in this region than in the extended XAFS (EXAFS) region. Therefore, XANES spectra can be used to probe the degree of disorder in the medium-range structural environment around Ti in crystalline and amorphous materials, including Ti-bearing aperiodic structures, such as metamict, glassy, and molten compounds. C1 UNIV PARIS 12, CNRS, UA 734, F-93166 NOISY LE GRAND, FRANCE. UNIV PARIS 12, LURE, F-93166 NOISY LE GRAND, FRANCE. STANFORD UNIV, DEPT GEOL & ENVIRONM SCI, STANFORD, CA 94305 USA. STANFORD UNIV, STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA 94305 USA. UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. RP UNIV PARIS 12, LAB PHYS & MECAN GEOMAT, F-93166 NOISY LE GRAND, FRANCE. NR 121 TC 187 Z9 187 U1 7 U2 41 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 1996 VL 60 IS 16 BP 3023 EP 3038 DI 10.1016/0016-7037(96)00144-5 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VC980 UT WOS:A1996VC98000007 ER PT J AU Farges, F Brown, GE Navrotsky, A Gan, H Rehr, JJ AF Farges, F Brown, GE Navrotsky, A Gan, H Rehr, JJ TI Coordination chemistry of Ti(IV) in silicate glasses and melts .2. Glasses at ambient temperature and pressure SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID X-RAY-ABSORPTION; MULTIPLE-SCATTERING CALCULATIONS; BOND-VALENCE PARAMETERS; CRYSTAL-STRUCTURE; EXAFS; XANES; TI; ENVIRONMENTS; TITANIUM; MINERALS AB The coordination environment of Ti(IV) in a number of Ti-silicate and Ti-aluminosilicate glasses has been determined by x-ray absorption fine structure (XAFS) spectroscopy at the Ti K-edge at ambient temperature and pressure. These glasses contain 2.7-30.5 wt% TiO2 and varying amounts of Na2O, K2O, or CaO (5.0-38.7 wt%) and Al2O3 (0-11.9 wt%), and have NBO/T ratios ranging from 0.07-0.81. Quantitative analysis of the Ti XANES spectra, based on ab initio multiple-scattering calculations for a variety of Ti-containing clusters, and anharmonic analysis of the normalized XAFS oscillations suggest the presence of three types of atoms around Ti: O first neighbors, (Si, Ti)-second neighbors, and alkali third neighbors. Five-coordinated Ti, Ti-[5], is the dominant Ti species in the glasses most concentrated in Ti (>16 wt% TiO2) and is located in distorted square pyramids ((TiO)-Ti-[5])O-4), with one short Ti=O titanyl distance (1.67-1.70 +/- 0.03 Angstrom) and four long Ti-O distances (1.94-1.95 +/- 0.02 Angstrom). In addition, minor amounts of Ti-[4] were detected, the proportion of Ti-[4] increasing in the order: Na glasses < K glasses. Ti-[4] is the dominant Ti species in the potassic glasses with the lowest TiO2 contents (approximate to 3-6 wt%) and highest NBO/T ratio. The relative amount of Ti-[4] increases in the order: Ca glass < K glass. Finally, Ti-[6] is a minor species (<20%) when detected in these glasses. The presence of Ti-(Si, Ti) correlations near 3.2-3.4 +/- 0.1 Angstrom, as in crystalline Na-2((TiO)-Ti-[5])SiO4, is consistent with (TiO5)-Ti-[5] and SiO4/TiO5 polyhedra sharing corners in these glasses, with Ti-O-(Si, Ti) angles of approximate to 120 degrees-130 degrees +/- 10 degrees, Quantitative analysis of the Ti K-edge XANES for the K-bearing glasses suggests the presence K around Ti, in good agreement with bond-valence predictions, which indicate that Ti-[5] is most likely to bond to both nonbridging oxygens (one O in short Ti=O titanyl bonds) and bridging oxygens (four O in long Ti-O bonds), thus can act as a new type of Q(4) specie with one additional nonbridging oxygen. Then, we propose [5]Ti to behave simultaneously a network former and a network modifier, with the network former role dominant. Bond valence models explain why the relative proportions of Ti-[4] and Ti-[5] change when the type of low field strength cation or the type of network-forming cation (Si vs. P) changes in oxide glasses. These models also provide a structural basis for the study Of glasses and melts at higher temperatures (see Part III of this study). C1 UNIV PARIS 12, CNRS, UA 734, F-93166 NOISY LE GRAND, FRANCE. UNIV PARIS 12, LURE, F-93166 NOISY LE GRAND, FRANCE. STANFORD UNIV, DEPT GEOL & ENVIRONM SCI, STANFORD, CA 94305 USA. STANFORD UNIV, STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA 94305 USA. PRINCETON UNIV, DEPT GEOL & GEOPHYS SCI, PRINCETON, NJ 08544 USA. UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. RP UNIV PARIS 12, LAB PHYS & MECAN GEOMAT, F-93166 NOISY LE GRAND, FRANCE. NR 65 TC 99 Z9 99 U1 5 U2 22 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 1996 VL 60 IS 16 BP 3039 EP 3053 DI 10.1016/0016-7037(96)00145-7 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VC980 UT WOS:A1996VC98000008 ER PT J AU Farges, F Brown, GE Navrotsky, A Gan, H Rehr, JR AF Farges, F Brown, GE Navrotsky, A Gan, H Rehr, JR TI Coordination chemistry of Ti(IV) in silicate glasses and melts .3. Glasses and melts from ambient to high temperatures SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID X-RAY-ABSORPTION; MULTIPLE-SCATTERING CALCULATIONS; SI-29 NMR; LIQUIDS; SPECTROSCOPY; DIFFRACTION; SYSTEMS; SPECTRA; RUTILE; EXAFS AB The local structural environment of Ti in five Na-, K-, and Ca-titanosilicate glass/melts with TiO2 concentrations ranging from 2.7-30.5 wt% has been determined by in situ Ti K-edge x-ray absorption fine structure (XAFS) spectroscopy at temperatures ranging from 293-1650 K. In parallel, two Ti-model compounds (Ni2.6Ti0.7O4 spinel and TiO2 rutile) were studied under the same conditions to better understand the effects of temperature (anharmonicity) on the XAFS spectra. Temperature-induced anharmonicity was found to vary, largely as a function of the Ti-coordination, and increases significantly around Ti with increasing temperature when present as Ti-[6]. In contrast, anharmonicity appears negligible around Ti-[4] at temperatures below 1200 K. We predict that anharmonicity should be weak around Ti-[5] as well. No clear evidence was found for a significant change in the average nearest-neighbor coordination environment of Ti in the Na- and K-titanosilicate glasses and melts that exhibit anomalous heat capacities variations just above their glass transition temperatures, T-g (860-930 K). The small (predicted and measured) linear thermal expansion of the ((TiO2+)-Ti-[5])-O bond in these systems at high temperature is expected to have an insignificant effect on the local environment of Ti-[5] during the glass-to-supercooled liquid transition. In the most dilute Ti-glass studied (KS1; 2.7 wt% TiO2), the local environment around Ti-[4] (especially the second-neighbor alkalis) is relatively ordered at ambient temperature, but this order decreases dramatically above T-g. Lower quench rates appear to favor Ti-[4] over Ti-[5]. The origin of the observed anomalous positive variations in heat capacities of these melts may be related to significant changes in the medium-range environment around Ti above T-g including the disappearance of percolation domains involving interfaces between alkali-rich and network-former rich regions during structural relaxation at T-g; these percolation domains are related to the dual structural role of Ti in silicate glass/melts (acting simultaneously as network former and network modifier). C1 UNIV PARIS 12,CNRS,UA 734,F-93166 NOISY LE GRAND,FRANCE. UNIV PARIS 12,LURE,F-93166 NOISY LE GRAND,FRANCE. STANFORD UNIV,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. PRINCETON UNIV,DEPT GEOL & GEOPHYS SCI,PRINCETON,NJ 08544. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. RP Farges, F (reprint author), UNIV PARIS 12,LAB PHYS & MECAN GEOMAT,F-93166 NOISY LE GRAND,FRANCE. NR 41 TC 79 Z9 79 U1 2 U2 21 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 1996 VL 60 IS 16 BP 3055 EP 3065 DI 10.1016/0016-7037(96)00146-9 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VC980 UT WOS:A1996VC98000009 ER PT J AU Happell, JD Wallace, DWR AF Happell, JD Wallace, DWR TI Methyl iodide in the Greenland/Norwegian Seas and the tropical Atlantic Ocean: Evidence for photochemical production SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEAWATER; ATMOSPHERE; MACROALGAE; KELP; CH3I; AIR AB CH3I was measured in open ocean waters during two cruises to the tropical Atlantic Ocean and a late fall cruise to the Greenland and Norwegian Seas (GSNS). In warm, tropical surface waters subject to high solar irradiance, average CH3I saturation anomalies were positive (1.5-7.7 pmol kg(-1)), indicating a sea-to-air flux. This contrasted with negative saturation anomalies (-0.65 +/- 0.02 pmol kg(-1)) measured in cold surface waters of the open ocean GSNS subject to low-light. High latitude oceans may therefore be a significant sink for atmospheric CH3I during the fall and winter. The locations and/or seasons where samples were analyzed were all characterized by relatively low biological production and the CH3I saturation anomaly along 19 degrees S decreased from 7.7 +/- 0.6 to 3.4 +/- 0.4 pmol kg(-1) when entering a more productive upwelling zone. Taken together these observations suggest a chemical, as opposed to biological, production mechanism for this compound in the open ocean. Within the open ocean of the GSNS, multiple linear regression between the observed CH3I saturation anomaly and variables including light intensity, water temperature, CFC-11 saturation (indicator of gas exchange and deep mixing), and distance from the Norwegian Coastal Current (indicator of coastal or southern sources) showed that light intensity was the only significant predictor, explaining 79% of the variance. Photochemical production may, therefore be dominant source of CH3I within the open ocean and this may have important implications for the large-scale, seasonal cycling of iodine between the ocean and the atmosphere. RP Happell, JD (reprint author), BROOKHAVEN NATL LAB,DIV OCEANOG & ATMOSPHER SCI,DEPT APPL SCI,BLDG 318,UPTON,NY 11973, USA. NR 26 TC 66 Z9 68 U1 0 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1996 VL 23 IS 16 BP 2105 EP 2108 DI 10.1029/96GL01764 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VA620 UT WOS:A1996VA62000027 ER PT J AU Novakov, T Corrigan, CE AF Novakov, T Corrigan, CE TI Cloud condensation nucleus activity of the organic component of biomass smoke particles SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AEROSOLS; EMISSIONS; FOREST; HAZE AB Natural and anthropogenic water-soluble inorganic aerosol species are efficient cloud condensation nuclei (CCN). Biomass smoke particles, although composed mostly of organic material, are also known to be efficient CCN. However because smoke particles consist of mixtures of organic and inorganic species, it has not been established whether the organic component is intrinsically CCN active or is intrinsically inactive and rendered CCN active only through association with water-soluble inorganic species. Here we report results of laboratory experiments on smoke particles produced by combustion of eucalyptus, redwood, and cellulose which show that their water-soluble organic fraction is principally derived from smoldering combustion of the cellulosic fuel content. Because cellulose smoke particles are entirely organic, water soluble, and CCN active (at 0.5% and 0.3% supersaturation), we conclude that the water-soluble organic species in smoke particles from smoldering biomass combustion are responsible for their intrinsic CCN activity. RP Novakov, T (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,MS-73,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 18 TC 131 Z9 134 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1996 VL 23 IS 16 BP 2141 EP 2144 DI 10.1029/96GL01971 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VA620 UT WOS:A1996VA62000036 ER PT J AU Elphic, RC Weiss, LA Thomsen, MF McComas, DJ Moldwin, MB AF Elphic, RC Weiss, LA Thomsen, MF McComas, DJ Moldwin, MB TI Evolution of plasmaspheric ions at geosynchronous orbit during times of high geomagnetic activity SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAGNETOSPHERIC PLASMA ANALYZER; OUTER PLASMASPHERE; BULGE REGION; DYNAMICS AB The evolution of the plasmasphere, the region of relatively dense cold plasma surrounding the Earth, is strongly dependent on magnetospheric activity. Here we report on plasmaspheric evolution as observed at geosynchronous orbit in association with magnetopause crossings and storm sudden commencements (SSCs). The occurrence frequency distributions at geosynchronous orbit of both magnetopause-associated and SSC-associated plasmaspheric ions is peaked near 1400 LT, with an overall range from 1000 LT to beyond 1800 LT. This is greatly skewed from the average plasmaspheric distribution at 6.6 R(E), which peaks closer to 1800 LT. The evolution of SSC-associated plasmaspheric ions is tracked using a superposed epoch analysis: lower-activity SSCs produce minor changes from the pre-SSC local time distribution; after geomagnetically-effective SSCs, the ions appear almost immediately at earlier local times, spanning the late morning to dusk local time sector for hours. These observations are consistent with (1) a push of plasmaspheric material inward over the spacecraft due to magnetospheric compression and (2) the prompt penetration of a convection electric field. C1 FLORIDA INST TECHNOL,DEPT PHYS & SPACE SCI,MELBOURNE,FL 32901. RP Elphic, RC (reprint author), LOS ALAMOS NATL LAB,SPACE & ATMOSPHER SCI GRP,MS D466,LOS ALAMOS,NM 87545, USA. RI Moldwin, Mark/F-8785-2011 OI Moldwin, Mark/0000-0003-0954-1770 NR 14 TC 73 Z9 74 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 1 PY 1996 VL 23 IS 16 BP 2189 EP 2192 DI 10.1029/96GL02085 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VA620 UT WOS:A1996VA62000048 ER PT J AU Dagle, GE Weller, RE Filipy, RE Watson, CR Buschbom, RL AF Dagle, GE Weller, RE Filipy, RE Watson, CR Buschbom, RL TI The distribution and effects of inhaled Pu-239(NO3)(4) deposited in the liver of dogs SO HEALTH PHYSICS LA English DT Article DE dogs; tumors; plutonium; inhalation ID BEAGLE DOGS; TUMORS; THOROTRAST; PLUTONIUM AB The distribution and effects of inhaled Pu-239(NO3)(4) deposited in the liver of dogs were studied in five groups of 20 beagles exposed to initial lung depositions ranging from 1.0 to 520 Bq g(-1) lung. Following life-span observations, the liver contained 40 +/- 1% of the final body deposition of plutonium, second only to the skeleton. The liver-to-skeleton ratio of deposited plutonium for total organ was 0.8, or 3.5 when expressed on a per-gram basis, There was no effect of exposure level on liver-to-skeleton ratios, Autoradiographs showed that the dose rate delivered to parenchymal cells was higher than evident from radiochemical analysis of the whole organ, Elevated levels of serum liver enzymes were observed in groups with mean liver concentrations of 1.3 Bq g(-1) and liver doses of 3 Gy or higher, Nodular hyperplasia of liver and bile-duct hyperplasia were observed, Liver tumors, principally of bile-duct epithelium, were late-occurring and mere observed at lower exposure levels at which life span was not shortened by lung or bone tumors. C1 PACIFIC NW NATL LAB, RICHLAND, WA 99352 USA. RP Dagle, GE (reprint author), WASHINGTON STATE UNIV, US TRANSURANIUM & URANIUM REGISTRIES, 100 SPROUT RD, TRI CITIES, RICHLAND, WA 99352 USA. RI WSU, USTUR/I-1056-2013 NR 29 TC 6 Z9 6 U1 0 U2 4 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 AUG PY 1996 VL 71 IS 2 BP 198 EP 205 DI 10.1097/00004032-199608000-00011 PG 8 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 UY099 UT WOS:A1996UY09900014 PM 8690603 ER PT J AU Toohey, RE Kathren, RL AF Toohey, RE Kathren, RL TI The probability of developing cancer due to a large dose of radiation - Response SO HEALTH PHYSICS LA English DT Letter C1 WASHINGTON STATE UNIV, US TRANSURANIUM & URANIUM REGISTRIES, RICHLAND, WA 99352 USA. RP Toohey, RE (reprint author), OAK RIDGE INST SCI & EDUC, RADIAT INTERNAL DOSE INFORMAT CTR, OAK RIDGE, TN 37831 USA. RI WSU, USTUR/I-1056-2013 NR 0 TC 0 Z9 0 U1 0 U2 2 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 AUG PY 1996 VL 71 IS 2 BP 248 EP 249 PG 2 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 UY099 UT WOS:A1996UY09900022 ER PT J AU Dolbeare, F AF Dolbeare, F TI Bromodeoxyuridine: A diagnostic tool in biology and medicine .3. Proliferation in normal, injured and diseased tissue, growth factors, differentiation, DNA replication sites and in situ hybridization SO HISTOCHEMICAL JOURNAL LA English DT Review ID CENTRAL-NERVOUS-SYSTEM; CELL NUCLEAR ANTIGEN; TUMOR-NECROSIS-FACTOR; RAT SPINAL-CORD; FLOW CYTOMETRIC ANALYSIS; BRDU ANTIBODY TECHNIQUE; SMOOTH-MUSCLE CELLS; THYMIDINE ANALOG 5-BROMO-2-DEOXYURIDINE; LABELED OLIGONUCLEOTIDE PROBES; MURINE ERYTHROLEUKEMIA-CELLS AB This paper is a continuation of parts I (history, methods and cell kinetics) and II (clinical applications and carcinogenesis) published previously (Dolbeare, 1995 Histochem. J. 27, 339, 923). Incorporation of bromodeoxyuridine (BrdUrd) into DNA is used to measure proliferation in normal, diseased and injured tissue and to follow the effect of growth factors. Immunochemical detection-of BrdUrd can be used to determine proliferative characteristics of differentiating tissues and to obtain birth dates for actual differentiation events. Studies are also described in which BrdUrd is used to follow the order of DNA replication in specific chromosomes, DNA replication sites in the nucleus and to monitor DNA repair. BrdUrd incorporation has been used as a tool for in situ hybridization experiments. RP Dolbeare, F (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL PROGRAM,LIVERMORE,CA 94551, USA. NR 531 TC 81 Z9 87 U1 2 U2 4 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0018-2214 J9 HISTOCHEM J JI Histochem.J. PD AUG PY 1996 VL 28 IS 8 BP 531 EP 575 DI 10.1007/BF02331377 PG 45 WC Cell Biology SC Cell Biology GA VK467 UT WOS:A1996VK46700001 PM 8894660 ER PT J AU Lu, B Lu, YC Cheng, JL Schneider, RP Zolper, JC Goncher, G AF Lu, B Lu, YC Cheng, JL Schneider, RP Zolper, JC Goncher, G TI Gigabit-per-second cryogenic optical link using optimized low-temperature AlGaAs-GaAs vertical-cavity surface-emitting lasers SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID SERIES RESISTANCE; OPERATION AB We describe the design of GaAs-AlGaAs vertical-cavity surface-emitting lasers (VCSEL's) that are optimized for operation at very low temperatures and the experimental demonstration of a free-space optical interconnect for cryogenic electronic systems using a VCSEL, We demonstrate high-speed modulation of the optical link at a data rate of up to 2 Gb/s at 77 K, with a very low bit-error rate of <10(-13), and thermally stable operation is achieved over a wide range of cryogenic temperatures without laser bias current compensation, Cryogenic VCSEL's with excellent lasing characteristics have been achieved over the entire temperature range from 150 K to 6 K, including high output power (22 mW), high power-conversion efficiency (32%), high slope efficiency (similar to 100%), low threshold voltage (1.75 V) and current (1.7 mA), as well as a high-modulation bandwidth (12 GHz) for a 16 mu m diameter device at 80 K. C1 UNIV NEW MEXICO,CTR HIGH TECHNOL MAT,ALBUQUERQUE,NM 87131. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. TEKTRONIX INC,BEAVERTON,OR 97077. NR 22 TC 7 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 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD AUG PY 1996 VL 32 IS 8 BP 1347 EP 1359 DI 10.1109/3.511547 PG 13 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA VA814 UT WOS:A1996VA81400010 ER PT J AU Bibeau, C Trenholme, JB Payne, SA AF Bibeau, C Trenholme, JB Payne, SA TI Pulse length and terminal-level lifetime dependence of energy extraction for neodymium-doped phosphate amplifier glass SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID CRYSTALS AB On the basis of detailed numerical calculations, we have;formulated an empirical expression for the saturation fluence in neodymium-doped phosphate amplifier glass that explicitly depends upon the ratio of the pulse width to the terminal-level lifetime, The empirical expression, when substituted within the Frantz-Nodvik solution for energy extraction, can be used to determine the impact of the lower level lifetime on the energy extracted from Nd:phosphate glass amplifiers, We used our empirical solution to model experimental gain-saturation data and determine the terminal-level lifetime, We compared this value with two independent experiments and found that all three experiments yielded similar results, The terminal-level lifetime of LG-750 at room temperature is found to be 253 ps +/- 50 ps. RP Bibeau, C (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. RI Trenholme, John/M-4805-2016 OI Trenholme, John/0000-0003-3673-6653 NR 17 TC 8 Z9 8 U1 0 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD AUG PY 1996 VL 32 IS 8 BP 1487 EP 1496 DI 10.1109/3.511562 PG 10 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA VA814 UT WOS:A1996VA81400025 ER PT J AU Smith, RE Sullivan, CT Vawter, GA Hadley, GR Wendt, JR Snipes, MB Klem, JF AF Smith, RE Sullivan, CT Vawter, GA Hadley, GR Wendt, JR Snipes, MB Klem, JF TI Reduced coupling loss using a tapered-rib adiabatic-following fiber coupler SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article ID QUANTUM-WELL LASERS; WAVE-GUIDE; BEAMWIDTH TRANSFORMERS; INP AB We present the design and experimental demonstration of a tapered-rib adiabatic-following fiber coupler (TRAF-FiC), This device is an adaptation of a Shani-Henry mode converter fabricated in (Al)GaAs and designed to increase the coupling efficiency of conventional optical fibers to tightly-confined semiconductor rib waveguide devices, This approach offers the potential of significantly reducing fiber butt coupling losses from the typical values of 7 to 10 dB to values of <1 dB, This long-standing packaging problem is one of the major impediments to the widespread acceptance of semiconductor-based optoelectronics. Moreover, the design can be implemented with minimal increase in fabrication complexity since it uses only a straightforward modification to epitaxial growth, and one additional lithography and etching step. RP Smith, RE (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 14 TC 10 Z9 10 U1 2 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD AUG PY 1996 VL 8 IS 8 BP 1052 EP 1054 DI 10.1109/68.508735 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA UY957 UT WOS:A1996UY95700031 ER PT J AU Gover, JE Peterson, MA AF Gover, JE Peterson, MA TI Guest editorial: A grass roots political role for IEEE-USA SO IEEE TRANSACTIONS ON ENGINEERING MANAGEMENT LA English DT Editorial Material RP Gover, JE (reprint author), SANDIA NATL LABS,EXECUT STAFF ORG,LIVERMORE,CA 94550, USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9391 J9 IEEE T ENG MANAGE JI IEEE Trans. Eng. Manage. PD AUG PY 1996 VL 43 IS 3 BP 239 EP 245 DI 10.1109/TEM.1996.511834 PG 7 WC Business; Engineering, Industrial; Management SC Business & Economics; Engineering GA VB945 UT WOS:A1996VB94500002 ER PT J AU Nijim, YW Stearns, SD Mikhael, WB AF Nijim, YW Stearns, SD Mikhael, WB TI Differentiation applied to lossless compression of medical images SO IEEE TRANSACTIONS ON MEDICAL IMAGING LA English DT Article AB Lossless compression of medical images using a proposed differentiation technique is explored, This scheme is based on computing weighted differences between neighboring pixel values, The performance of the proposed approach, for the lossless compression of magnetic resonance (MR) images and ultrasonic images, is evaluated and compared with the lossless linear predictor and the lossless Joint Photographic Experts Group (JPEG) standard, The residue sequence of these techniques is coded using arithmetic: coding, The proposed scheme yields compression measures, in terms of bits per pixel, that are comparable with or lower than those obtained using the linear predictor and the lossless JPEG standard, respectively, with 8-b medical images, The advantages of the differentiation technique presented here over the linear predictor are: 1) the coefficients of the differentiator are known by the encoder and the decoder, which eliminates the need to compute or encode these coefficients, and 2) the computational complexity is greatly reduced, These advantages are particularly attractive in real time processing for compressing and decompressing medical images. C1 UNIV CENT FLORIDA,DEPT ELECT ENGN,ORLANDO,FL 32816. VELA RES,ST PETERSBURG,FL 33716. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 8 TC 11 Z9 11 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0278-0062 J9 IEEE T MED IMAGING JI IEEE Trans. Med. Imaging PD AUG PY 1996 VL 15 IS 4 BP 555 EP 559 DI 10.1109/42.511758 PG 5 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Computer Science; Engineering; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA VA943 UT WOS:A1996VA94300015 PM 18215936 ER PT J AU Matthews, PJ Berenc, T Schoenfeld, F Feinerman, AD Kang, YW Kustom, R AF Matthews, PJ Berenc, T Schoenfeld, F Feinerman, AD Kang, YW Kustom, R TI Electromagnetic field measurements on a millimeter wave linear accelerator SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article AB Perturbational field strength measurements suitable for use on a proposed 120-GHz 50-MeV electron linear accelerator are described, The measurements are used to determine the R/Q of the device, where R is the shunt impedance. The perturbation is achieved by the use of hollow metallic cylinders with diameters ranging from 25 to 127 mu m which are approximately 500 mu m long. The cylinders were fabricated by sputtering aluminum through a shadow mask onto silica optical fibers as well as nylon surgical thread, The perturbational ''form factors'' for such a geometry are experimentally determined using a pillbox cavity, The measured values for the form factors are compared to theoretical estimations, which result in simple analytical expressions, The measured form factors are also compared to values calculated from a finite difference model of the perturbing object, The R/Q for various accelerating modes is measured on a 12-GHz model of the 120-GHz structure. Results are compared to predictions from a finite difference model of the accelerating structure. C1 ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439. BERLINER ELEKTRONENSPEICHERING GESELL SYNCHROTONS,BERLIN,GERMANY. UNIV ILLINOIS,CHICAGO,IL 60607. RP Matthews, PJ (reprint author), USN,RES LAB,DIV OPT SCI,WASHINGTON,DC 20375, USA. NR 14 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD AUG PY 1996 VL 44 IS 8 BP 1401 EP 1409 DI 10.1109/22.536022 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA VC774 UT WOS:A1996VC77400002 ER PT J AU Comanor, KA Virador, PRG Moses, WW AF Comanor, KA Virador, PRG Moses, WW TI Algorithms to identify detector Compton scatter in PET modules SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1995 Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY OCT 21-28, 1995 CL SAN FRANCISCO, CA ID PIN PHOTODIODE; DESIGN; DEPTH AB Using Monte Carlo simulation, we investigate algorithms to identify and correct for detector Compton scatter in hypothetical PET modules with 3x3x30 mm EGO crystals coupled to individual photosensors. Rather than assume a particular design, we study three classes of detectors: (1) with energy resolution limited by counting statistics, (2) with energy resolution limited by electronic noise, and (3) with depth of interaction (DOI) measurement capability. For the first two classes, selecting the channel with the highest signal as the crystal of interaction yields a 22-25% misidentification fraction (MIF) for all reasonable noise fwhm to signal (N/S) ratios (i.e. <0.5 at 511 keV). Algorithms that attempt to correctly position events that undergo forward Compton scatter using only energy information can reduce the MIF to 12%, and can be easily realized with counting statistics limited detectors but can only be achieved with very low noise values for noise limited detectors. When using position of interaction to identify forward scatter, a MTF of 12% can be obtained if the detector has good energy and position resolution. RP Comanor, KA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 7 TC 39 Z9 39 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1996 VL 43 IS 4 BP 2213 EP 2218 DI 10.1109/23.531884 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA VD777 UT WOS:A1996VD77700006 ER PT J AU Hsieh, YL Gullberg, GT Zeng, GL Huesman, RH AF Hsieh, YL Gullberg, GT Zeng, GL Huesman, RH TI Image reconstruction using a generalized natural pixel basis SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1995 Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY OCT 21-28, 1995 CL SAN FRANCISCO, CA ID LINEAR INVERSE PROBLEMS; DISCRETE-DATA; DECOMPOSITION AB The solution q of the imaging equation Mq=FGq=p (F is the projector and G is a generalized backprojector) is determined using least squares, thus various basis functions can be used as an expansion for the reconstructed image. In this paper a generalized natural pixel basis is chosen to allow flexibility in formulating the vector space for the solution q. The singular value decomposition (SVD) method is used to solve for q, and the final image is obtained by backprojecting q: p = Gq, and sampling p at a discrete array of points. Truncated parallel and non-truncated fan beam projection measurements were used to demonstrate that the solution q to Mq=FGq=p can be defined wherein, for example, if F is a fan beam projection operator, G can be a parallel backprojection operator defined based upon natural pixels. It is demonstrated that different backprojection geometries can give almost equivalent reconstructions of non-truncated projections. For truncated projections the estimation of q that covers the entire projection of the object is effective in reducing ring artifacts; however, using more projection bins is much more effective in preserving the resolution than is increasing the projection bin width. Also, a generalized natural pixel basis better models the geometric response of a collimator used in SPECT, therefore reconstructions of fan beam projections using generalized natural pixels are shown to have better resolution than those that use the filtered backprojection algorithm. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Hsieh, YL (reprint author), UNIV UTAH,DEPT RADIOL,SALT LAKE CITY,UT 84132, USA. NR 14 TC 14 Z9 14 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1996 VL 43 IS 4 BP 2306 EP 2319 DI 10.1109/23.531896 PN 1 PG 14 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA VD777 UT WOS:A1996VD77700018 ER PT J AU Schaich, PC Clark, GA Sengupta, SK Ziock, KP AF Schaich, PC Clark, GA Sengupta, SK Ziock, KP TI Automatic image analysis for detecting and quantifying gamma-ray sources in coded-aperture images SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article AB We report the development of an automatic image analysis system that detects gamma-ray source regions in images obtained from a coded aperture, gamma-ray imager. The number of gamma sources in the image Is not known prior to analysis, The system counts the number (Ii) of gamma sources detected in the image and estimates the lower bound for the probability that the number of sources in the image is K. The system consists of a two-stage pattern classification scheme in which the probabilistic neural network is used in the supervised learning mode, The algorithms were developed and tested using real gamma-ray images from controlled experiments in which the number and location of depleted uranium source disks in the scene are known, The novelty of the work lies in the creative combination of algorithms and the successful application of the algorithms to real images of gamma-ray sources. C1 UNIV CALIF DAVIS,CTR IMAGE PROC & INTEGRATED COMPUTING,CIPIC,DAVIS,CA 95616. RP Schaich, PC (reprint author), LAWRENCE LIVERMORE NATL LAB,L-156,LIVERMORE,CA 94551, USA. NR 21 TC 7 Z9 7 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1996 VL 43 IS 4 BP 2419 EP 2426 DI 10.1109/23.531791 PN 2 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA VD778 UT WOS:A1996VD77800011 ER PT J AU Carlsten, BE Haynes, WB AF Carlsten, BE Haynes, WB TI Discrete monotron oscillator SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID KLYSTRON AMPLIFIERS; ELECTRON-BEAM; CAVITY; PHYSICS AB We theoretically and numerically investigate the operation and behavior of the discrete monotron oscillator, a novel high-power microwave source. The discrete monotron differs from conventional monotrons and transit time oscillators by shielding the electron beam from the monotron cavity's RF fields except at two distinct locations, This makes the discrete monotron act more like a klystron than a distributed traveling wave device. As a result, the oscillator has higher efficiency and can operate with higher beam powers than other single cavity oscillators and has more stable operation without requiring a seed input signal than mildly relativistic, intense-beam klystron oscillators. RP Carlsten, BE (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544, USA. NR 16 TC 5 Z9 7 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 1996 VL 24 IS 4 BP 1249 EP 1258 DI 10.1109/27.536572 PG 10 WC Physics, Fluids & Plasmas SC Physics GA VH229 UT WOS:A1996VH22900008 ER PT J AU Kavicky, JA Shahidehpour, SM AF Kavicky, JA Shahidehpour, SM TI Parallel path aspects of transmission modeling SO IEEE TRANSACTIONS ON POWER SYSTEMS LA English DT Article DE power systems operations; transmission open access; parallel paths ID MULTIAREA AB This paper examines the present methods and modeling techniques available to address the effects of parallel flows resulting from various firm and short-term energy transactions. A survey of significant methodologies is conducted to determine the present status of parallel flow transaction modeling. The strengths and weaknesses of these approaches are identified to suggest areas of further modeling improvements. The motivating force behind this research is to improve transfer capability assessment accuracy by suggesting a real-time modeling environment that adequately represents the influences of parallel flows while recognizing operational constraints and objectives. C1 IIT,DEPT ELECT & COMP ENGN,CHICAGO,IL 60616. RP Kavicky, JA (reprint author), ARGONNE NATL LAB,DECIS & INFORMAT SCI DIV,ARGONNE,IL 60439, USA. NR 27 TC 14 Z9 14 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-8950 J9 IEEE T POWER SYST JI IEEE Trans. Power Syst. PD AUG PY 1996 VL 11 IS 3 BP 1180 EP 1186 DI 10.1109/59.535589 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA VE603 UT WOS:A1996VE60300015 ER PT J AU Sharan, RN Schneeweiss, FHA Feinendegen, LE AF Sharan, RN Schneeweiss, FHA Feinendegen, LE TI Neutrons affect ADP-ribosylation of proteins in human kidney T1-cells in vitro SO INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS LA English DT Article ID DNA; POLY(ADP-RIBOSYL)ATION; MECHANISM; CHROMATIN; REPAIR; DAMAGE AB ADP-ribosylation (ADPR) of proteins has been shown to be involved with a variety of cellular responses in which chromatin organization and functions are affected. In order to look into this response, human kidney Tl-cells were exposed in vitro to various doses up to 3 Gy of 6 MeV neutrons and compared with the effect caused by gamma photons. Whereas in case of neutrons the maximal inhibition of ADPR was reversed at 0.37 qt that in case of gamma-rays occurred at 1.5 Gy. For the reversal of inhibition of ADPR of proteins in Tl-cells, neutrons were about 4-fold more efficient as compared to gamma rays. C1 FORSCHUNGSZENTRUM JULICH, RES CTR, INST MED, D-52425 JULICH, GERMANY. US DOE, CTN, MED APPLICAT & BIOPHYS RES DIV, WASHINGTON, DC 20585 USA. RP Sharan, RN (reprint author), NE HILL UNIV, SCH LIFE SCI, DEPT BIOCHEM, RADIAT & MOL BIOL UNIT, SHILLONG 793022, MEGHALAYA, INDIA. RI Sharan, Rajeshwar/L-3007-2016 OI Sharan, Rajeshwar/0000-0002-7120-8023 NR 22 TC 6 Z9 7 U1 0 U2 0 PU NATL INST SCIENCE COMMUNICATION PI NEW DELHI PA DR K S KRISHNAN MARG, NEW DELHI 110 012, INDIA SN 0301-1208 J9 INDIAN J BIOCHEM BIO JI Indian J. Biochem. Biophys. PD AUG PY 1996 VL 33 IS 4 BP 281 EP 284 PG 4 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA VA799 UT WOS:A1996VA79900005 PM 8936817 ER PT J AU Amundson, SA Chen, DJ Okinaka, RT AF Amundson, SA Chen, DJ Okinaka, RT TI Alpha particle mutagenesis of human lymphoblastoid cell lines SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID DOUBLE-STRAND BREAKS; GRADIENT GEL-ELECTROPHORESIS; DENSELY IONIZING-RADIATION; DIPLOID HUMAN-LYMPHOBLASTS; THYMIDINE KINASE LOCUS; MUTATION-INDUCTION; MYELOID-LEUKEMIA; TK-LOCUS; X-RAYS; DNA AB Despite being derived from the same donor, the human lymphoblastoid cell lines WTK1 and TK6 have markedly different responses to low LET radiation. We originally observed that WTK1 was more resistant to the cytotoxic effects of X-irradiation, but significantly more sensitive to mutation induction at both the TK and HPRT loci. In an effort to better understand these properties, we have examined the effects of alpha-particles on these cells. Relative to TK6, WTK1 has enhanced survival and mutation after both X-ray and alpha-particle exposure. While the HPRT locus was significantly more mutable in WTK1 as a function of alpha-particle versus X-ray dose, the TK locus was only slightly more sensitive to alpha-particle mutagenesis. In addition, the slowly growing TK mutants that constitute the majority of X-ray-induced TK mutants of TK6 were recovered in lower proportions following alpha-particle exposures. This is consistent with the further finding that in both cell lines, loss of heterozygosity occurred in a smaller fraction of ct-induced TK mutants than X-ray-induced mutants. These results are consistent with our previous model suggesting that WTK1 has an error-prone repair pathway that is either missing or deficient in TK6, and further suggest that this pathway may be involved in the processing of alpha-particle-induced damage. C1 LOS ALAMOS NATL LAB,LIFE SCI DIV LS6,LOS ALAMOS,NM. FU NCI NIH HHS [CA5644] NR 53 TC 9 Z9 9 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD AUG PY 1996 VL 70 IS 2 BP 219 EP 226 DI 10.1080/095530096145210 PG 8 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VF329 UT WOS:A1996VF32900011 PM 8794851 ER PT J AU Schreyer, HL Neilsen, MK AF Schreyer, HL Neilsen, MK TI Discontinuous bifurcation states for associated smooth elasticity and damage with isotropic elasticity SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article ID FLUTTER INSTABILITY; PLANE-STRAIN; ELASTOPLASTICITY; LOCALIZATION; DEFORMATION AB For many constitutive equations the tangent tensor consists of a rank one modification to the isotropic elasticity tensor with a total of two elasticity parameters and one parameter describing the current state of inelasticity. For small deformations, general expressions are derived for the loss of ellipticity, the corresponding normal to the bifurcation plane and the mode of discontinuous bifurcation for the velocity gradient. If the principal basis of an evolution tensor is used, the current stress or strain state is characterized by two additional parameters. The small number of material and state parameters makes it feasible to use contour plots to illustrate all possible combinations that can provide a discontinuous bifurcation. These bifurcation maps can be used to illustrate the bifurcation properties of a particular plasticity or continuum damage constitutive model. Conversely, the bifurcation maps can be used in conjunction with experimental data on bifurcation features to assist in the development of constitutive equations that provide the correct failure criterion for a given material under all possible stress paths. C1 SANDIA NATL LABS,ENGN & MFG MECH DEPT,ALBUQUERQUE,NM 87185. RP Schreyer, HL (reprint author), UNIV NEW MEXICO,DEPT MECH ENGN,ALBUQUERQUE,NM 87131, USA. NR 28 TC 19 Z9 19 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD AUG PY 1996 VL 33 IS 20-22 BP 3239 EP 3256 DI 10.1016/0020-7683(96)00001-7 PG 18 WC Mechanics SC Mechanics GA UV406 UT WOS:A1996UV40600020 ER PT J AU Joslyn, C AF Joslyn, C TI Aggregation and completion of random sets with distributional fuzzy measures SO INTERNATIONAL JOURNAL OF UNCERTAINTY FUZZINESS AND KNOWLEDGE-BASED SYSTEMS LA English DT Article DE general information theory; distributional random sets; complete random sets; decomposable fuzzy measures ID INFORMATION AB The two known information theories, probability and possibility theory, are based on t-conorm decomposable fuzzy measures, so that bijective mappings exist between their set-valued measures and their point-valued distributions. Further, their random set (Dempster-Shafer evidence theoretical) interpretations have simple topological structures, with bijective mappings between the subset focal elements and the point singletons. We introduce the concepts of distributional and aggregable random sets and random set completion, and first use them as a model in which to cast probability and possibility measures and distributions. Then, towards the goal of deriving new forms of information theory, general Sugeno conorm decomposable fuzzy measures and ring-like aggregable random sets with set-intersection structural aggregation are examined, but it is shown that in these two cases no new information theories are forthcoming. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 39 TC 5 Z9 5 U1 2 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-4885 J9 INT J UNCERTAIN FUZZ JI Int. J. Uncertainty Fuzziness Knowl.-Based Syst. PD AUG PY 1996 VL 4 IS 4 BP 307 EP 329 DI 10.1142/S0218488596000184 PG 23 WC Computer Science, Artificial Intelligence SC Computer Science GA VP432 UT WOS:A1996VP43200001 ER PT J AU Hagelberg, CR Bennett, AF Jones, DA AF Hagelberg, CR Bennett, AF Jones, DA TI Local existence results for the generalized inverse of the vorticity equation in the plane SO INVERSE PROBLEMS LA English DT Article ID OCEAN CIRCULATION; MODEL; ASSIMILATION AB We prove the finite-time existence of a solution to the Euler-Lagrange equations corresponding to the necessary conditions for minimization of a functional defining variational assimilation of observational data into the two-dimensional, incompressible Euler equations. The data are given by linear functionals acting on the space of functions representing vorticity. The data are sparse and available on a fixed space-time domain. The objective of the data assimilation is to obtain an estimate of the vorticity which minimizes a cost functional and is analogous to a distributed parameter control problem. The cost functional is the sum of a weighted squared error in the dynamics, the initial condition, and in the misfit to the observed data. Vorticity estimates which minimize the cost functional are obtained by solving the corresponding system of Euler-Lagrange equations. The Euler-Lagrange system is a coupled two-point boundary value problem in time. An application of the Schauder fixed-point theorem establishes the existence of a least one solution to the system. Iterative methods for generating solutions have proven useful in applications in meteorology and oceanography. C1 COLL OCEAN & ATMOSPHER SCI,CORVALLIS,OR 97331. ARIZONA STATE UNIV,DEPT MATH,TEMPE,AZ 85287. RP Hagelberg, CR (reprint author), LOS ALAMOS NATL LAB,EES-5 MS C400,LOS ALAMOS,NM 87545, USA. RI Hagelberg, Carl/E-9554-2014 OI Hagelberg, Carl/0000-0002-2073-3127 NR 19 TC 12 Z9 12 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0266-5611 J9 INVERSE PROBL JI Inverse Probl. PD AUG PY 1996 VL 12 IS 4 BP 437 EP 454 DI 10.1088/0266-5611/12/4/007 PG 18 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA VC811 UT WOS:A1996VC81100007 ER PT J AU Gibaud, A Wang, J Tolan, M Vignaud, G Sinha, SK AF Gibaud, A Wang, J Tolan, M Vignaud, G Sinha, SK TI An X-ray scattering study of laterally modulated structures: Investigation of coherence and resolution effects with a grating SO JOURNAL DE PHYSIQUE I LA English DT Article ID TRUNCATION RODS; SURFACES; DIFFRACTION AB An X-ray scattering experiment at small angle of incidence from the laterally modulated structure of a grating is reported. The attention is mainly focused on the determination of the linewidth of the different diffracted orders observed in transverse scans parallel to the surface of the grating. It is shown that the width of the different orders decreases when the incident angle increases and that the evolution of the width is consistent with the evolution of the instrumental resolution. It is also shown that if the spatial coherence of the beam is defined by the angular apertures of the incident and outgoing beams a identical behavior is expected at least when the diffracted orders are well separated. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. CHRISTIAN ALBRECHTS UNIV KIEL,INST EXPTL PHYS,D-2300 KIEL 1,GERMANY. EUROPEAN SYNCHROTRON RADIAT FACIL,F-38043 GRENOBLE,FRANCE. RP Gibaud, A (reprint author), UNIV MAINE,FAC SCI,URA 807 CNRS,EQUIPE PHYS ETAT CONDENSE,BP 535,F-72017 LE MANS,FRANCE. NR 10 TC 8 Z9 8 U1 0 U2 3 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4304 J9 J PHYS I JI J. Phys. I PD AUG PY 1996 VL 6 IS 8 BP 1085 EP 1094 PG 10 WC Physics, Multidisciplinary SC Physics GA UX989 UT WOS:A1996UX98900008 ER PT J AU Holstege, DM Galey, FD Johnson, B Seiber, JN AF Holstege, DM Galey, FD Johnson, B Seiber, JN TI Determination of alkaloid exposure in a model ruminant (goat) using a multiresidue screening method SO JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY LA English DT Article DE alkaloid; analysis; Delphinium barbeyi; Conium maculatum; Nicotiana glauca; Datura wrightii; Taxus baccata; ruminant; goat ID HEMLOCK CONIUM-MACULATUM; CATTLE; TOXICOSIS; TOXICITY; PLANTS AB A new multiresidue analytical screen for estimating alkaloid exposure in livestock has been evaluated on biological samples from goats dosed with sublethal amounts of five plants known to cause acute poisoning in animals. The plant species selected were Conium maculatum (poison hemlock), Nicotiana glauca (tree tobacco), Delphinium barbeyi (larkspur), Datura wrightii (jimsonweed), and Taxus baccata (English yew). Animals were euthanized when toxic signs developed or when 3-7 hours had passed after the dose. The liver, kidney, rumen contents, abomasal contents, urine, and serum from each animal were examined for the presence of alkaloids. Alkaloid contents were determined by GC with nitrogen-phosphorus detection, GC/MS, and a modified commercial thin layer chromatography system. Alkaloids from the plants were detected at levels greater than 1 mu g/g in samples of rumen and abomasal contents and in most urine, kidney and liver samples. No alkaloids were detected in serum samples at concentrations greater than 0.5 mu g/g. The multiresidue screening method enabled identification and quantitation of alkaloids in biological samples from goats dosed with sub-lethal amounts of the five plants. C1 LAWRENCE LIVERMORE NATL LAB,DEPT ENVIRONM TOXICOL,DAVIS,CA 95616. RP Holstege, DM (reprint author), LAWRENCE LIVERMORE NATL LAB,CALIF VET DIAGNOST LAB SYST,TOXICOL LAB,DAVIS,CA 95616, USA. NR 26 TC 6 Z9 6 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-8561 J9 J AGR FOOD CHEM JI J. Agric. Food Chem. PD AUG PY 1996 VL 44 IS 8 BP 2310 EP 2315 DI 10.1021/jf950091x PG 6 WC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology SC Agriculture; Chemistry; Food Science & Technology GA VC709 UT WOS:A1996VC70900062 ER PT J AU Marking, GA Young, VG Franzen, HF AF Marking, GA Young, VG Franzen, HF TI New group V kappa-phases SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE kappa-phases; group V elements; X-ray crystal structure; neutron diffraction; superconductivity ID TA-NB-S; CRYSTAL-STRUCTURE; TERNARY-SYSTEM; COMPOUND; TANTALUM AB New kappa-phases (P. Rautala and J.T. Norton, Trans. AIME 194 (1952) 1045; A. Harsta and S. Rundqvist, J. Solid State Chem., 70 (1987) 210) were discovered and crystallographically characterized in the Zr-Ta-S, Zr-Nb-S, Zr-V-S, Hf-Nb-S, and Hf-V-S systems. A kappa-phase was also identified in the Hf-Ta-S system through Guinier powder diffraction. These compounds are the first examples of the kappa-phase structure containing the Group V transition metals, Ta, Nb, and V. The Ta and Nb kappa-phases exhibit the largest volumes (by about 13%) and the largest amounts of second row nonmetal per formula unit of the known kappa-phases. X-ray single-crystal diffraction experiments were used to determine metal site occupancies in these kappa-phases, and it was found that statistical mixing of the metals primarily on one site occurred for the Ta and Nb compounds. Refinements of the X-ray intensity data indicated that the octahedral nonmetal sites (denoted X2) are less than fully occupied by sulfur in the Ta and Nb kappa-phases and less than fully occupied by oxygen in the V kappa-phases. Combined neutron and X-ray powder refinements reliably determined that these nonmetal X2 sites are occupied by a mixture of sulfur, oxygen, and vacancies in the Zr-Nb-S and Zr-Ta-S kappa-phases. The kappa-phases in the Zr-Nb-S (G. Marking et al., Phys. Rev. B, 48 (1993) 16630) and Hf-Nb-S systems were found to be superconductors with T(c)s of 10.35 K and between 6 and 7 K respectively. C1 IOWA STATE UNIV,AMES LAB,DOE,AMES,IA 50011. NR 46 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD AUG 1 PY 1996 VL 241 IS 1-2 BP 98 EP 111 DI 10.1016/0925-8388(96)02349-3 PG 14 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA VG432 UT WOS:A1996VG43200017 ER PT J AU Klesnar, H Aselage, TL Morosin, B Kwei, GH Lawson, AC AF Klesnar, H Aselage, TL Morosin, B Kwei, GH Lawson, AC TI The diboride compounds of molybdenum: MoB2-x and Mo2B5-y SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE molybdenum diboride; phase relations; structure; neutron diffraction ID TRANSITION-METAL BORIDES; CRYSTALS; BORON AB The phase relations of the molybdenum diboride compounds MoB2-x and Mo2B5-y and the structure of Mo2B5-y have been re-examined with samples prepared between 1400 and 1800 degrees C. Two types of six-membered boron ring, nearly planar and puckered, occur within the Mo2B5-y structure. The sites at the centers of the puckered rings may be unoccupied (K' layers) or occupied by boron atoms (K layers). Neutron diffraction refinements show that these sites are completely unoccupied (K' layers) in Mo2B5-y samples of several batch compositions. This result, combined with the insensitivity of the unit cell dimensions of Mo2B5-y to batch composition, shows that this phase has a narrow single phase region, with y close to unity, between 1400 and 1800 degrees C. MoB2-x also has a narrow single-phase region centered at about 61 at.% boron over this temperature range. C1 SANDIA NATL LABS,LIVERMORE,CA 94550. RP Klesnar, H (reprint author), UNIV NEW MEXICO,SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 14 TC 29 Z9 29 U1 1 U2 8 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD AUG 1 PY 1996 VL 241 IS 1-2 BP 180 EP 186 DI 10.1016/0925-8388(96)02294-3 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA VG432 UT WOS:A1996VG43200029 ER PT J AU Serimaa, R Etelaniemi, V Serimaa, O Laitalainen, T Bienenstock, A AF Serimaa, R Etelaniemi, V Serimaa, O Laitalainen, T Bienenstock, A TI An improved regularization technique for analysis of anomalous X-ray scattering data; Platinum uridine blue sulfate as an example SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID SMALL-ANGLE SCATTERING; MAXIMUM-ENTROPY METHOD; AMORPHOUS MATERIALS; INTEGRAL-EQUATIONS; CRYSTAL-STRUCTURE; PYRIMIDINE BLUES; ALPHA-PYRIDONATE; COMPLEXES; DIFFRACTION; LIGANDS AB A new iterative way to apply the Tikhonov regularization method for solving partial structure factors from anomalous X-ray scattering data is presented. It is used to obtain the regularized Pt-Pt partial structure factor in a complex amorphous material, platinum uridine blue, containing many atomic species, utilizing experimental anomalous wide-angle X-ray scattering data. Since only platinum has a suitable absorption edge for the measurement, the problem is very much ill-posed, and without regularization only unreliable solutions are obtained. The average Pt-Pt distances, determined from the Pt-Pt partial distribution function, are 3.0 and 5.7 Angstrom and the coordination number at 3.0 Angstrom is about 1. Accordingly, the dominating Pt-structures of Pt-uridine blue are dinuclear. The success of this method indicates that we may use anomalous scattering to obtain important, detailed information about the structure of very complex amorphous materials. C1 CTR COMP SCI,FIN-02101 ESPOO,FINLAND. UNIV HELSINKI,DEPT CHEM,FIN-00014 HELSINKI,FINLAND. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. RP Serimaa, R (reprint author), UNIV HELSINKI,DEPT PHYS,POB 9,FIN-00014 HELSINKI,FINLAND. NR 47 TC 11 Z9 11 U1 1 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 1996 VL 29 BP 390 EP 402 DI 10.1107/S0021889895016979 PN 4 PG 13 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA VF650 UT WOS:A1996VF65000013 ER PT J AU Dragoi, D Watkins, TR Kozaczek, KJ AF Dragoi, D Watkins, TR Kozaczek, KJ TI Interpreting oscillatory Bragg peak positions SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID ORIENTATION AB This work describes a detector-fixed method in which X-ray photons are collected on different points of the sensitive area of the detector without movement of the detector and which is suitable for measuring a single-crystal orientation using (omega, phi) rotations. This method was used to determine the orientation of a silicon wafer whose (100) plane makes a small angle (misorientation angle) with the surface. omega scans of the 400 reflection were measured as a function of phi while chi and 28 were fixed at 0 and 69 degrees, respectively. C1 OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. RP Dragoi, D (reprint author), UNIV DENVER,DENVER,CO 80210, USA. RI Watkins, Thomas/D-8750-2016 OI Watkins, Thomas/0000-0002-2646-1329 NR 7 TC 0 Z9 0 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 1996 VL 29 BP 493 EP 494 DI 10.1107/S0021889896000684 PN 4 PG 2 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA VF650 UT WOS:A1996VF65000030 ER PT J AU He, L Franzen, HF Johnson, DC AF He, L Franzen, HF Johnson, DC TI Synthesis and characterization of Pt-Ti4O7 microelectrode arrays SO JOURNAL OF APPLIED ELECTROCHEMISTRY LA English DT Article ID DISK ELECTRODE; DIFFUSION CURRENT; DETECTORS AB The synthesis of Pt-Ti4O7 microelectrode arrays is achieved from mixtures of TiO2 and Ti2O3 powders plus Pt particles by a thermal procedure commonly used in solid-state chemistry. Data obtained for the Pt-Ti4O7 materials by X-ray diffractometry and scanning electron microscopy are consistent with the existence of heterogeneous mixtures of Pt particles imbedded within the conductive Ti4O7 matrices. Rotated disc electrodes (RDEs) constructed from pure Pt and from the Pt-Ti4O7 materials are compared on the basis of their voltammetric and amperometric response for I- and H2O2 in 0.10M H2SO4. The observed enhancement of current densities for the Pt-Ti4O7 RDEs is rationalized on the basis of the behaviour expected for microelectrode arrays. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP He, L (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011, USA. NR 27 TC 23 Z9 23 U1 2 U2 17 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0021-891X J9 J APPL ELECTROCHEM JI J. Appl. Electrochem. PD AUG PY 1996 VL 26 IS 8 BP 785 EP 793 DI 10.1007/BF00683740 PG 9 WC Electrochemistry SC Electrochemistry GA VD870 UT WOS:A1996VD87000002 ER PT J AU Verboncoeur, JP Parker, GJ Penetrante, BM Morgan, WL AF Verboncoeur, JP Parker, GJ Penetrante, BM Morgan, WL TI Comparison of collision rates in particle-in-cell, Monte Carlo, and Boltzmann codes SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RF GLOW-DISCHARGES; CROSS-SECTIONS; IONIZATION; MODEL AB Computational modeling is a key tool for studying collisional plasma discharges, including capacitive, inductive, and de discharges. This work compares electron-neutral collision rates for a particle-in-cell code, a Monte Carlo code, a convected scheme Boltzmann code, and a spherical harmonic expansion Boltzmann code. In addition, comparisons with swarm experiments are presented where available. The comparison is performed over a range of reduced fields, E/N, appropriate to ac plasma display panels. The background gas is neon, with a simplified set of representative reactions. Ion and space charge effects are neglected. (C) 1996 American Institute of Physics. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. KINEMA RES & SOFTWARE, MONUMENT, CO 80132 USA. NR 21 TC 11 Z9 11 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1996 VL 80 IS 3 BP 1299 EP 1303 DI 10.1063/1.362929 PG 5 WC Physics, Applied SC Physics GA VA594 UT WOS:A1996VA59400007 ER PT J AU Woodworth, JR Riley, ME Meister, DC Aragon, BP Le, MS Sawin, HH AF Woodworth, JR Riley, ME Meister, DC Aragon, BP Le, MS Sawin, HH TI Ion energy and angular distributions in inductively coupled radio frequency discharges in argon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RF REFERENCE CELL; GLOW-DISCHARGES; PLASMA; BOMBARDMENT; DENSITY; SHEATH; MODEL; AR AB We report measurements of the energies and angular distributions of positive ions in an inductively coupled argon plasma in a Gaseous Electronics Conference Reference Cell. Use of two separate ion detectors allowed measurement of ion energies and fluxes as a function of position as well as ion angular distributions on the discharge centerline. The inductive drive on our system produced high plasma densities (up to 10(12)/cm(3) electron densities) and relatively stable plasma potentials. As a result, ion energy distributions typically consisted of a single feature well separated from zero energy. Mean ion energy was independent of rf power and Varied inversely with pressure, decreasing from 29 to 12 eV as pressure increased from 2.4 to 50 mTorr, The half-widths of the ion angular distributions in these experiments varied from 5 degrees to 9 degrees, or equivalently, the transverse temperatures varied from 0.18 to 0.29 eV with the distributions broadening as either pressure or rf power was increased. (C) 1996 American Institute of Physics. C1 MIT,DEPT ELECT ENGN,CAMBRIDGE,MA 02139. RP Woodworth, JR (reprint author), SANDIA NATL LABS,LASER OPT & REMOTE SENSING DEPT,ALBUQUERQUE,NM 87185, USA. NR 40 TC 82 Z9 82 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1996 VL 80 IS 3 BP 1304 EP 1311 DI 10.1063/1.362977 PG 8 WC Physics, Applied SC Physics GA VA594 UT WOS:A1996VA59400008 ER PT J AU Lee, DH Park, B Poker, DB Riester, L Feng, ZC Baglin, JEE AF Lee, DH Park, B Poker, DB Riester, L Feng, ZC Baglin, JEE TI Surface hardness enhancement in ion-implanted amorphous carbon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID NITRIDE THIN-FILMS; NITROGEN IMPLANTATION; RAMAN-SPECTROSCOPY; GLASSY-CARBON; SUPERHARD; DIAMOND; SCATTERING; GRAPHITE; SOLIDS AB The feasibility of producing carbon nitride has been studied by ion implantation into amorphous carbon. Thin films were formed with 100 keV N+ or 80 keV C+ ions al various target temperatures and ion doses. The apparent surface hardness measured by nanoindentation with load-displacement data shows an optimum value of 22.3 +/- 0.4 GPa with the ion dose of 2 X 10(17) N+/cm(2) implanted at -100 degrees C, while the hardness of the unimplanted amorphous carbon is 6.0 +/- 0.2 GPa. Self-implantation by carbon also produces similar hardness enhancement with a narrow temperature window. The maximum enhanced surface hardness is well correlated with the asymmetric diffuse peak at around 1500 cm(-1) in Raman spectroscopy. (C) 1996 American Institute of Physics. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. IBM CORP,ALMADEN RES CTR,SAN JOSE,CA 95120. RP Lee, DH (reprint author), GEORGIA INST TECHNOL,SCH MAT SCI & ENGN,ATLANTA,GA 30332, USA. RI Park, Byungwoo/F-5431-2013 NR 25 TC 17 Z9 17 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1996 VL 80 IS 3 BP 1480 EP 1484 DI 10.1063/1.363017 PG 5 WC Physics, Applied SC Physics GA VA594 UT WOS:A1996VA59400031 ER PT J AU Weir, ST Mitchell, AC Nellis, WJ AF Weir, ST Mitchell, AC Nellis, WJ TI Electrical resistivity of single-crystal Al2O3 shock-compressed in the pressure range 91-220 GPa (0.91-2.20 Mbar) SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PHASE-TRANSITION; TEMPERATURES; SAPPHIRE AB The electrical resistivity of single-crystal Al2O3 was measured at shock pressures in the range 91-220 GPa. Shock pressures were generated by impacts of hypervelocity projectiles accelerated with a two-stage light-gas gun. The resistivity varied from 170 to 20 Ohm cm in the pressure range 91-180 GPa and then rapidly decreased to 0.2 Ohm cm at 220 GPa. (C) 1996 American Institute of Physics. RP Weir, ST (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Weir, Samuel/H-5046-2012 NR 17 TC 44 Z9 48 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1996 VL 80 IS 3 BP 1522 EP 1525 DI 10.1063/1.362946 PG 4 WC Physics, Applied SC Physics GA VA594 UT WOS:A1996VA59400039 ER PT J AU Dimos, D AlShareef, HN Warren, WL Tuttle, BA AF Dimos, D AlShareef, HN Warren, WL Tuttle, BA TI Photoinduced changes in the fatigue behavior of SrBi2Ta2O9 and Pb(Zr,Ti)O-3 thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FERROELECTRIC CAPACITORS; HYSTERESIS CHANGES; ELECTRODES; CERAMICS; LIGHT AB It is shown that SrBi2Ta2O9(SBT) thin films can be made to exhibit significant polarization fatigue by electric-field cycling under broad-band, optical illumination. Photoinduced fatigue is also observed for Pb(Zr,Ti)O-3 (PZT) thin-film capacitors with (La,Sr)CoO3 (LSCO) electrodes. These results demonstrate that both the Pt/SBT/Pt and the LSCO/PZT/LSCO systems are susceptible to fatigue effects, which are attributed primarily to pinning of domain walls due to charge trapping. Capacitors that have been fatigued under illumination can be fully rejuvinated by applying a dc saturating bias with light or by electric-field cycling without light, which indicates an intrinsic, field-assisted recovery mechanism. We suggest that fatigue is essentially a competition between domain wall pinning and unpinning and that domain pinning is not necessarily absent in these nominally fatigue-free systems, but rather these systems are ones in which unpinning occurs at least as rapidly as any pinning. In both cases, the extent of photoinduced fatigue decreases with increased cycling voltage, indicating the relative importance of field-assisted unpinning. Finally, the observation of photoinduced fatigue implies that increased injection rates, potentially due to oxygen vacancy accumulation, may account for the electrode dependence on fatigue in PZT thin films. RP Dimos, D (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Alshareef, Husam Niman/A-2000-2015 OI Alshareef, Husam Niman/0000-0001-5029-2142 NR 29 TC 157 Z9 159 U1 1 U2 21 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1996 VL 80 IS 3 BP 1682 EP 1687 DI 10.1063/1.362968 PG 6 WC Physics, Applied SC Physics GA VA594 UT WOS:A1996VA59400064 ER PT J AU Vergara, G HerreraGomez, A Spicer, WE AF Vergara, G HerreraGomez, A Spicer, WE TI Electron transverse energy distribution in GaAs negative electron affinity cathodes: Calculations compared to experiments SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB The transverse momentum of photoelectrons released from a negative electron affinity GaAs cathode is small compared with other thermonic or field emission electron sources. A low photoelectron transverse momentum in vacuum promises highly focused, low-energy beams useful for numerous applications. A simplified theory for electron emission from GaAs predicts much lower electron transverse momentum than those previously measured experimentally. To address this theory-experiment mismatch, Monte Carlo based calculations were compared with experimental data. We checked the possibility of there being electron scattering in the Cs,O layer; however, none of the scattering checked (isotropically distributed, cosine distributed, and Rutherford scattering) properly fit the experimental results. The assumption of conservation of the parallel component of the crystal momentum k during the emission is mainly believed to be responsible for the calculation-theory disagreement. The best simulation-experiment fit was obtained through a relaxation of the conditions imposed on the transverse momentum inside and outside of the semiconductor when an ideal interface is considered. We obtained the best results by assuming that the effective mass of the electron inside GaAs is equal to the effective mass of the electron in vacuum. Two independent experiments confirmed that in both cases, this same-mass approximation gives the best fit. The physical meaning of this is not clear, but it seems to be related to the amorphous nature of the Cs,O layer. We conclude that the way to get lower electron transverse energy spread cathodes is to study alternative activation methods and new materials with smaller effective electron masses. (C) 1996 American Institute of Physics. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. CTR INVEST & DESARROLLO ARMADA,MADRID 28033,SPAIN. UAQ,CINVESTAV,LAB INVEST MAT,QUERETARO 76010,MEXICO. RP Vergara, G (reprint author), STANFORD UNIV,STANFORD ELECTR LABS,STANFORD,CA 94305, USA. RI Vergara Ogando, German/B-9706-2015 OI Vergara Ogando, German/0000-0002-9406-1335 NR 15 TC 16 Z9 17 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1996 VL 80 IS 3 BP 1809 EP 1815 DI 10.1063/1.362992 PG 7 WC Physics, Applied SC Physics GA VA594 UT WOS:A1996VA59400083 ER PT J AU Welipitiya, D He, YL Zhang, JD Oden, PI Thundat, T Warmack, RJ Gobulukoglu, I Shan, ZS Sellmyer, DJ Dowben, PA AF Welipitiya, D He, YL Zhang, JD Oden, PI Thundat, T Warmack, RJ Gobulukoglu, I Shan, ZS Sellmyer, DJ Dowben, PA TI Fabrication of large arrays of micron-scale magnetic features by selective area organometallic chemical vapor deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SCANNING TUNNELING MICROSCOPE; EPITAXIAL GD FILMS; PHASE-TRANSITIONS; GROWTH; DECOMPOSITION; ANISOTROPY; PALLADIUM; LITHOGRAPHY; HYSTERESIS; PARTICLES AB We demonstrate that it is possible to deposit a wide range of magnetic features, using photoassisted selective area organometallic chemical vapor deposition. Large arrays of identical micron-scale Ni features were deposited on a Si(111) wafer by this method. Their magnetic properties were studied by alternating gradient force magnetometry as well as magnetic force microscopy. Our morphological and magnetic measurements show that the structures are spatially well defined, and the magnetic properties are related to the structural shapes of the features. This method can be adapted to the fabrication of smaller-scale magnetic and electronic devices. (C) 1996 American Institute of Physics. C1 UNIV NEBRASKA,CTR MAT RES & ANAL,LINCOLN,NE 68588. UNIV NEBRASKA,DEPT PHYS & ASTRON,LINCOLN,NE 68588. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,HLTH SCI RES DIV,MOL IMAGING GRP,OAK RIDGE,TN 37831. NR 62 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1996 VL 80 IS 3 BP 1867 EP 1871 DI 10.1063/1.362999 PG 5 WC Physics, Applied SC Physics GA VA594 UT WOS:A1996VA59400090 ER PT J AU King, PE Nyman, MD AF King, PE Nyman, MD TI Modeling and control of an electric arc furnace using a feedforward artificial neural network SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Previous studies have shown that the electric arc furnace is chaotic in nature and hence standard control techniques are not effective. However, human (heuristic) control is used every day on electric arc furnaces. A furnace operator assesses the performance of the furnace and makes judgments based on past experience and intuition. In order to improve the effectiveness of this control, a qualitative understanding of the operating conditions of the furnace is required. Artificial neural networks are capable of learning the system dynamics of the electric arc furnace. This article describes a feedforward neural network trained to model arc furnace electrical wave forms taken from an experimental arc furnace. The output of this model is then used in estimating the future state of the furnace for control purposes. RP King, PE (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 14 TC 12 Z9 13 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1996 VL 80 IS 3 BP 1872 EP 1877 DI 10.1063/1.363000 PG 6 WC Physics, Applied SC Physics GA VA594 UT WOS:A1996VA59400091 ER PT J AU Wos, L AF Wos, L TI The power of combining resonance with heat SO JOURNAL OF AUTOMATED REASONING LA English DT Article DE automated reasoning; hot list strategy; resonance strategy; proof checking ID STRATEGY AB In this article, I present experimental evidence of the value of combining two strategies each of which has proved powerful in various contexts. The resonance strategy gives preference (for directing a program's reasoning) to equations or formulas that have the same shape (ignoring variables) as one of the patterns supplied by the researcher to be used as a resonator. The hot list strategy rearranges the order in which conclusions are drawn, the rearranging caused by immediately visiting and, depending on the value of the heat parameter, even immediately revisiting a set of input statements chosen by the researcher; the chosen statements are used to complete applications of inference rules rather than to initiate them. Combining these two strategies often enables an automated reasoning program to attack deep questions and hard problems with far more effectiveness than using either alone. The use of this combination in the context of cursory proof checking produced most unexpected and satisfying results, as I show here. I present the material (including commentary) in the spirit of excerpts from an experimenter's notebook, thus meeting the frequent request to illustrate how a researcher can make wise choices from among the numerous options offered by McCune's automated reasoning program OTTER. I include challenges and topics for research and, to aid the researcher, in the Appendix a sample input file and a number of intriguing proofs. C1 ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. NR 15 TC 4 Z9 4 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-7433 J9 J AUTOM REASONING JI J. Autom. Reasoning PD AUG PY 1996 VL 17 IS 1 BP 23 EP 81 PG 59 WC Computer Science, Artificial Intelligence SC Computer Science GA VF045 UT WOS:A1996VF04500002 ER PT J AU Wilson, AK Bhattacharyya, MH AF Wilson, AK Bhattacharyya, MH TI Calcium-induced gene changes in bone cells. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 ARGONNE NATL LAB,ARGONNE,IL 60439. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD AUG PY 1996 VL 11 SU 1 BP M386 EP M386 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA VA495 UT WOS:A1996VA49500733 ER PT J AU Lane, NE Thompson, JM Haupt, DL Breunig, T Kinney, JH AF Lane, NE Thompson, JM Haupt, DL Breunig, T Kinney, JH TI The early changes in osteoclast activity and trabecular connectivity in a rat model of estrogen deficiency SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 UNIV CALIF SAN FRANCISCO,SAN FRANCISCO,CA 94143. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD AUG PY 1996 VL 11 SU 1 BP S514 EP S514 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA VA495 UT WOS:A1996VA49500493 ER PT J AU Ryaby, JT Magee, FP Haupt, DL Kinney, JH AF Ryaby, JT Magee, FP Haupt, DL Kinney, JH TI Reversal of osteopenia in ovariectomized rats with combined magnetic fields as assessed by X-ray tomographic microscopy. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 ORTHOLOG CORP,PHOENIX,AZ. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD AUG PY 1996 VL 11 SU 1 BP S564 EP S564 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA VA495 UT WOS:A1996VA49500544 ER PT J AU Kinney, JH Ladd, AJC Haupt, DL Majumdar, S AF Kinney, JH Ladd, AJC Haupt, DL Majumdar, S TI A predictive model for assessing bone properties. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV CALIF SAN FRANCISCO,SAN FRANCISCO,CA 94143. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD AUG PY 1996 VL 11 SU 1 BP T423 EP T423 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA VA495 UT WOS:A1996VA49501239 ER PT J AU Fisher, IA Bell, AT AF Fisher, IA Bell, AT TI A comparative study of CO and CO2 hydrogenation over Rh/SiO2 SO JOURNAL OF CATALYSIS LA English DT Article ID SUPPORTED RHODIUM CATALYSTS; CARBON-MONOXIDE HYDROGENATION; PROMOTED RH(111) SURFACE; RH-CATALYSTS; METAL-OXIDES; PRODUCT DISTRIBUTIONS; TITANIA OVERLAYERS; KINETIC-PARAMETERS; THERMAL-DESORPTION; SILICA CATALYSTS AB The hydrogenation of CO and CO2 over Rh/SiO2 have been investigated for the purpose of identifying the similarities and differences between these two reaction systems. In situ infrared spectroscopy was used to characterize the surface of the catalyst. Exposure of the catalyst to CO or CO2 produced very similar infrared spectra in which the principal features are those for linearly and bridge-bonded CO. In the case of CO2 adsorption, a band for weakly adsorbed CO2 could also be observed. For identical reaction conditions the rate of CO2 hydrogenation to methane is higher than that for CO hydrogenation. The activation energy for CO hydrogenation is 23.2 kcal/mol and that for CO2 hydrogenation is 16.6 kcal/mol. The partial pressure dependances on H-2 and COz (z = 1, 2) are 0.67 and -0.80, respectively, for CO hydrogenation, and 0.53 and -0.46, respectively, for CO2 hydrogenation. Infrared spectroscopy reveals that under reaction conditions the catalyst surface is nearly saturated by adsorbed CO. The spectra observed during CO and CO2 hydrogenation are similar, the principal difference being that the CO coverage during CO hydrogenation is somewhat higher than that during CO2 hydrogenation. The CO coverage is insensitive to Hz partial pressure, but increases slightly with increasing COz partial pressure. Transient-response experiments demonstrate that the adsorbed CO is a critical intermediate in both reaction systems. It is proposed that the rate determining step in the formation of methane is the dissociation of H2CO, produced by the stepwise hydrogenation of adsorbed CO. A rate expression derived from the proposed mechanism properly describes the experimentally observed reaction kinetics both under steady-state and transient-response conditions. (C) 1996 Academic Press, Inc. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. RP Fisher, IA (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV CHEM SCI,BERKELEY,CA 94720, USA. NR 88 TC 78 Z9 79 U1 3 U2 44 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9517 J9 J CATAL JI J. Catal. PD AUG PY 1996 VL 162 IS 1 BP 54 EP 65 DI 10.1006/jcat.1996.0259 PG 12 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA VE260 UT WOS:A1996VE26000006 ER PT J AU Soran, PD Neal, EE Smith, B Mullen, KI AF Soran, PD Neal, EE Smith, B Mullen, KI TI On-line surfactant monitoring by foam generation SO JOURNAL OF CHEMICAL EDUCATION LA English DT Article ID LIQUID-LIQUID-EXTRACTION; ANIONIC SURFACTANTS; ABSORPTION C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. DUKE UNIV,DURHAM,NC 27706. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. NR 16 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD AUG PY 1996 VL 73 IS 8 BP 819 EP 821 PG 3 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA VA561 UT WOS:A1996VA56100052 ER PT J AU Feller, D Apra, E Nichols, JA Bernholdt, DE AF Feller, D Apra, E Nichols, JA Bernholdt, DE TI The structure and binding energy of K+-ether complexes: A comparison of MP2, RI-MP2, and density functional methods SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR WAVE-FUNCTIONS; CONFIGURATION-INTERACTION CALCULATIONS; GAUSSIAN-BASIS SETS; BENCHMARK CALCULATIONS; SYSTEMATIC SEQUENCES; DIATOMIC HYDRIDES; CROWN-ETHERS; AB-INITIO; GAS-PHASE; ATOMS AB The structures and binding energies of several cation:ether complexes (K+:dimethyl ether, K+:dimethoxyethane, K+:12-crown-4 and K+:18-crown-6) were determined with second and fourth order perturbation theory using correlation consistent basis sets. Several of these are the largest correlated calculations yet attempted on crown ethers. The observed systematic convergence to the complete basis set limit provides a standard by which the accuracy of previous studies can be measured and facilitates the calibration of density functional methods. Recent Fouler transform ion cyclotron resonance experiments predicted K+:18-crown-6 binding energies which were significantly smaller than ab initio calculations. None of the potential sources of error examined in the present study were large enough to explain this difference. Although the 6-31+G* basis set used in an earlier theoretical study was smaller than the smallest of the correlation consistent basis sets, with suitable correction for basis set superposition error, it appears capable of yielding binding energies within several kcal/mol of the basis set limit. Perturbation theory calculations exploiting the ''resolution of the identity'' approximation were found to faithfully reproduce binding energies and conformational differences. Although the cation-ether interaction is dominated by classical electrostatics, the accuracy of density functional techniques was found to be quite sensitive to the choice of functionals. The local density SVWN procedure performed well for binding energies and conformational differences, while underestimating K+O distances by up to 0.08 Angstrom. The gradient-corrected Becke-Lee-Yang-Parr functional underestimated the K+:12c4 binding energy by 4-7 kcal/mol or 15%. (C) 1996 American Institute of Physics. RP PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Apra, Edoardo/F-2135-2010; OI Apra, Edoardo/0000-0001-5955-0734; Nichols, Jeffrey/0000-0001-5454-9726 NR 52 TC 54 Z9 54 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 AUG 1 PY 1996 VL 105 IS 5 BP 1940 EP 1950 DI 10.1063/1.472082 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UZ525 UT WOS:A1996UZ52500020 ER PT J AU Hummer, G Szabo, A AF Hummer, G Szabo, A TI Calculation of free-energy differences from computer simulations of initial and final states SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PHOTOSYNTHETIC REACTION CENTER; ELECTRON-TRANSFER; MOLECULAR-DYNAMICS; IONIZABLE GROUPS; PROTEINS; HYDRATION; WATER; MODEL; POTENTIALS; LYSOZYME AB A class of simple expressions of increasing accuracy for the free-energy difference between two states is derived based on numerical thermodynamic integration. The implementation of these formulas requires simulations of the initial and fnal (and possibly a few intermediate) states. They involve higher free-energy derivatives at these states which are related to the moments of the probability distribution of the perturbation. Given a specified number of such derivatives, these integration formulas are optimal in the sense that they are exact to the highest possible order of free-energy perturbation theory. The utility of this approach is illustrated for the hydration free energy of water. This problem provides a quite stringent test because the free energy is a highly nonlinear function of the charge so that even fourth order perturbation theory gives a very poor estimate of the free-energy change. Our results should prove most useful for complex, computationally demanding problems where foe-energy differences arise primarily from changes in the electrostatic interactions (e.g., electron transfer, charging of ions, protonation of amino acids in proteins). (C) 1996 American Institute of Physics. C1 LOS ALAMOS NATL LAB, CTR NONLINEAR STUDIES, LOS ALAMOS, NM 87545 USA. NIDDKD, CHEM PHYS LAB, NIH, BETHESDA, MD 20892 USA. RP Hummer, G (reprint author), LOS ALAMOS NATL LAB, THEORET BIOL & BIOPHYS GRP T10, MS K710, LOS ALAMOS, NM 87545 USA. RI Szabo, Attila/H-3867-2012; Hummer, Gerhard/A-2546-2013 OI Hummer, Gerhard/0000-0001-7768-746X NR 45 TC 114 Z9 116 U1 4 U2 24 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1996 VL 105 IS 5 BP 2004 EP 2010 DI 10.1063/1.472068 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UZ525 UT WOS:A1996UZ52500026 ER PT J AU Kalyuzhnyi, YV Cummings, PT AF Kalyuzhnyi, YV Cummings, PT TI Solution of the Chandler-Silbey-Ladanyi equation for the multicomponent hard-sphere site-site molecular fluid: Percus-Yevick approximation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIRECTIONAL ATTRACTIVE FORCES; STATISTICAL MECHANICAL MODELS; PROPER INTEGRAL-EQUATIONS; GREEN-YVON EQUATION; ANALYTIC SOLUTION; RISM EQUATION; CHEMICAL-REACTIONS; CHAIN FLUIDS; DUMBBELL FLUID; POLYMER MELTS AB The analytical solution of the Chandler-Silbey-Ladanyi Percus-Yevick (CSL-PY) approximation for multicomponent molecular site-site fluids is presented. The molecules are modeled by a collection of an arbitrary number of hard-sphere sites of any size and geometrical arrangement, provided only that all sites are in contact and the bonding distance is equal to the contact distance between the sites of the molecule. Assuming an additional approximation for the intramolecular correlation between the molecular sites not bonded directly the solution is extended to the case of flexible molecules. A closed-form analytical expression for the compressibility equation of state is derived. In the case of the linear flexible chain model polymer system, this equation of state coincides with the equation of state derived earlier [Y. C. Chiew, Mel. Phys. 70, 129 (1990)]. Comparison of the theory with computer simulation results shows that predictions of the CSL-PY theory for the compressibility pressure of the star polymer system is fairly accurate, while the structural predictions for linear chain n-mers are quantitatively accurate only for the systems of dimers. (C) 1996 American Institute of Physics. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. INST CONDENSED MATTER PHYS,UA-290011 LVOV,UKRAINE. RP Kalyuzhnyi, YV (reprint author), UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996, USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 65 TC 15 Z9 16 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1996 VL 105 IS 5 BP 2011 EP 2019 DI 10.1063/1.472069 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UZ525 UT WOS:A1996UZ52500027 ER PT J AU Lee, SH Cummings, PT AF Lee, SH Cummings, PT TI Shear viscosity of model mixtures by nonequilibrium molecular dynamics .2. Effect of dipolar interactions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSPORT PROCESSES; LIQUID; SIMULATION; KRYPTON; ARGON; FLOW AB a recent paper [Lee and Cummings, J. Chem. Phys. 99, 3919 (1993)], we presented nonequilibrium molecular dynamics calculations of the shear viscosity of pure liquid argon, pure liquid krypton, and argon/krypton liquid mixtures at constant temperature (T=135 K) and pressure (P=40 bar) as the base case for a consistent study of the role of intermolecular potentials on the transport properties of molecular liquids and their mixtures. In this paper, nonequilibrium molecular dynamics is used to study the shear viscosity of pure dipolar fluids, polar/nonpolar fluid mixtures, and polar/polar fluid mixtures at the same temperature and pressure. The fluids are assumed to interact via Lennard-Jones intermolecular potentials augmented by point dipole/point dipole potentials in the case of polar/polar interactions. By comparing the computed shear viscosity with that for corresponding nonpolar pure fluids and mixtures, the effect of dipolar interactions on the shear viscosity can be clearly delineated. (C) 1996 American Institute of Physics. C1 UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. KYUNGSUNG UNIV,DEPT CHEM,PUSAN 608736,SOUTH KOREA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 18 TC 17 Z9 17 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1996 VL 105 IS 5 BP 2044 EP 2055 DI 10.1063/1.472073 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UZ525 UT WOS:A1996UZ52500031 ER PT J AU Kaufman, EN Little, MH Selvaraj, PT AF Kaufman, EN Little, MH Selvaraj, PT TI Recycling of FGD gypsum to calcium carbonate and elemental sulfur using mixed sulfate-reducing bacteria with sewage digest as a carbon source SO JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY LA English DT Article DE gypsum sludge; sulfate-reducing bacteria; sulfur; calcium carbonate; flue gas desulfurization ID MICROBIAL REDUCTION; HYDROGEN-SULFIDE; ELECTRON-DONORS; GAS; DIOXIDE; REMOVAL; ENERGY AB A combined chemical and biological process for the recycling of flue gas desulfurization (FGD) gypsum into calcium carbonate and elemental sulfur is demonstrated. In this process, a mixed culture of sulfate-reducing bacteria (SRB) utilizes sewage digest as its carbon source to reduce FGD gypsum to hydrogen sulfide. The sulfide is then oxidized to elemental sulfur via reaction with ferric sulfate, and accumulating calcium ions are precipitated to calcium carbonate using carbon dioxide. Employing anaerobically digested-municipal sewage sludge (AD-MSS) medium as a carbon source, SRB in serum bottles demonstrated an FGD gypsum reduction rate of 8 mg dm(-3) h(-1) (10(9) cells)(-1). A chemostat with continuous addition of both AD-MSS medium and gypsum exhibited sulfate reduction rates as high as 1.3 kg FGD gypsum m(-3) day(-1). The increased biocatalyst density afforded by cell immobilization in a columnar reactor allowed a productivity of 152 mg SO4 dm(-3) h(-1) or 6.6 kg FGD gypsum m(-3) day(-1). Both reactors demonstrated 100% conversion of sulfate, with 75-100% recovery of elemental sulfur and as high as 70% COD utilization. Calcium carbonate was recovered from the reactor effluent upon precipitation using carbon dioxide. The formation of two marketable products-elemental sulfur and calcium carbonate-from FGD gypsum sludge, combined with the use of a low-cost carbon source and further improvements in reactor design, promises to offer an attractive alternative to the landfilling of FGD gypsum. RP Kaufman, EN (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,BIOPROC RES & DEV CTR,OAK RIDGE,TN 37831, USA. NR 32 TC 16 Z9 16 U1 2 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0268-2575 J9 J CHEM TECHNOL BIOT JI J. Chem. Technol. Biotechnol. PD AUG PY 1996 VL 66 IS 4 BP 365 EP 374 DI 10.1002/(SICI)1097-4660(199608)66:4<365::AID-JCTB520>3.0.CO;2-1 PG 10 WC Biotechnology & Applied Microbiology; Chemistry, Multidisciplinary; Engineering, Environmental; Engineering, Chemical SC Biotechnology & Applied Microbiology; Chemistry; Engineering GA VB665 UT WOS:A1996VB66500006 ER PT J AU Straughan, B Walker, DW AF Straughan, B Walker, DW TI Two very accurate and efficient methods for computing eigenvalues and eigenfunctions in porous convection problems SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID SPURIOUS EIGENVALUES; SPECTRAL METHODS; STABILITY; EQUATION; LAYER AB We develop the compound matrix method and the Chebyshev tau method to be applicable to linear and nonlinear stability problems for convection in porous media, in a natural way. It is shown how to obtain highly accurate answers to problems which may be stiff, and spurious eigenvalues are avoided. A detailed analysis is provided for a porous convection problem of much current interest, namely convection with a horizontally varying temperature gradient. (C) 1996 Academic Press, Inc. C1 UNIV GLASGOW,DEPT MATH,GLASGOW G12 8QW,LANARK,SCOTLAND. RP Straughan, B (reprint author), OAK RIDGE NATL LAB,MATH SCI SECT,POB 2008,OAK RIDGE,TN 37831, USA. RI Walker, David/B-7978-2010; OI Walker, David/0000-0002-1360-6330 NR 26 TC 57 Z9 57 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD AUG PY 1996 VL 127 IS 1 BP 128 EP 141 DI 10.1006/jcph.1996.0163 PG 14 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA VB430 UT WOS:A1996VB43000011 ER PT J AU Yoo, SS Rodricks, B Sivananthan, S Faurie, JP Montano, PA AF Yoo, SS Rodricks, B Sivananthan, S Faurie, JP Montano, PA TI Synchrotron x-ray photoconductor detector arrays made on MBE grown CdTe SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 1995 US Workshop on the Physics and Chemistry of Mercury Cadmium Telluride and Other IR Materials CY OCT 10-12, 1995 CL BALTIMORE, MD DE linear array photoconductor; molecular beam epitaxy (MBE) CdTe; synchrotron x-ray; x-ray detector ID MOLECULAR-BEAM EPITAXY; DEPOSITED CDTE; MISORIENTED SI(001); CDTE(111)B; FILMS AB We have been fabricating x-ray photoconductor linear array detectors using molecular beam epitaxially (MBE) grown (111)B undoped CdTe layers on (100) Si substrates. A novel technique was developed to remove the Si and to mount the fragile MBE grown CdTe layers onto insulating ceramic substrates. 256 channel linear photoconductor array devices were fabricated on the resulting CdTe layers. The resistivity of MBE (111)B CdTe was high (>10(8) Omega cm) enough to utilize the material for low energy (8 similar to 25 keV) x-ray detectors. The stability of the detectors are satisfactory, and they were tested at room temperature routinely for over a year. The performance of the photoconductor was greatly improved when the detector was cooled to 230K. Due to its reduced dark current at low temperatures, the dynamic range of the detector response increased to nearly four decades at 230K. C1 ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. RP Yoo, SS (reprint author), UNIV ILLINOIS,DEPT PHYS,MICROPHYS LAB,CHICAGO,IL 60607, USA. NR 28 TC 3 Z9 3 U1 1 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD AUG PY 1996 VL 25 IS 8 BP 1306 EP 1311 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA VC702 UT WOS:A1996VC70200028 ER PT J AU VanScyoc, JM Lund, JC Morse, DH Antolak, AJ Olsen, RW James, RB Schieber, M Yoon, H Goorsky, MS Toney, J Schlesinger, TE AF VanScyoc, JM Lund, JC Morse, DH Antolak, AJ Olsen, RW James, RB Schieber, M Yoon, H Goorsky, MS Toney, J Schlesinger, TE TI Material inhomogeneities in Cd1-xZnxTe and their effects on large volume gamma-ray detectors SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 1995 US Workshop on the Physics and Chemistry of Mercury Cadmium Telluride and Other IR Materials CY OCT 10-12, 1995 CL BALTIMORE, MD DE CdZnTe; gamma-ray detectors AB Cadmium zinc telluride (Cd1-xZnxTe or CZT) has shown great promise as a material for room temperature x-ray and gamma-ray detectors. In particular, polycrystalline material grown by the high pressure Bridgman method with nominal Zn fraction (x) from 0.1 to 0.2 has been used to fabricate high resolution gamma-ray spectrometers with resolution approaching that of cooled high-purity Ge. For increased sensitivity, large areas (> 1 cm(2)) are required, and for good sensitivity to high energy gamma photons, thick detectors (on the order of 1 cm) are required. Thus, there has been a push for the development of CZT detectors with a volume greater than 1 cm(3). However, nonuniformities in the material over this scale degrade the performance of the detectors. Variations in the zinc fraction, and thus the bandgap, and changes in the impurity distributions, both of which arise from the selective segregation of elements during crystal growth,result in spectral distortions. In this work, several materials characterization techniques were combined with detector evaluations to determine the materials properties limiting detector performance. Materials measurements were performed on detectors found to have differing performance. Measurements conducted include infrared transmission, particle induced x-ray emission, photoluminescence, and triaxial x-ray diffraction. To varying degrees, these measurements reveal that ''poor-performance'' detectors exhibit higher nonuniformities than ''spectrometer-grade'' detectors. This is reasonable, as regions of CZT material with different properties will give different localized spectral responses, which combine to result in a degraded spectrum for the total device. C1 UNIV CALIF LOS ANGELES,DEPT MAT SCI & ENGN,LOS ANGELES,CA 90024. CARNEGIE MELLON UNIV,DEPT ELECT & COMP ENGN,PITTSBURGH,PA 15213. RP VanScyoc, JM (reprint author), SANDIA NATL LABS,ADV ELECTR MFG DEPT,LIVERMORE,CA 94550, USA. NR 6 TC 8 Z9 8 U1 1 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD AUG PY 1996 VL 25 IS 8 BP 1323 EP 1327 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA VC702 UT WOS:A1996VC70200031 ER PT J AU Tang, Y AF Tang, Y TI Heuristic-based algorithm for active control SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article AB A simple effective control algorithm, free from the problem of time delay, is proposed. It is a closed-open loop control. The control force is applied to the structure at the current time to cancel the portion of the system velocity that is induced by the response and the external load at the preceding time step. This control concept is motivated by the fact that, for a single degree of freedom (SDOF) structure subjected to external loadings, the energy of the external load is imparted to the structure by changing the structural velocity. A simple, closed-form equation is used to compute the control force for SDOF systems, and for multiple degree-of-freedom (MDOF) systems, it is used in conjunction with the mode-superposition method. Numerical examples are used to demonstrate the effectiveness of the proposed control algorithm. A strategy for coping with the spillover effect is also proposed. The results of the examples show that the proposed control algorithm can reduce the maximum structural response by one order of magnitude and has the ability to reduce the peak that occurs during the first few cycles of the time history, an ability that linear control laws lack. Unlike most control algorithms that deal with the state space of the system that usually involves complex-valued eigenvalues and eigenvectors, the proposed control algorithm deals with the real-valued normal modes of the system. RP Tang, Y (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD AUG PY 1996 VL 122 IS 8 BP 801 EP 803 DI 10.1061/(ASCE)0733-9399(1996)122:8(801) PG 3 WC Engineering, Mechanical SC Engineering GA UX997 UT WOS:A1996UX99700014 ER PT J AU Neugebauer, M Goldstein, BE Smith, EJ Feldman, WC AF Neugebauer, M Goldstein, BE Smith, EJ Feldman, WC TI Ulysses observations of differential alpha-proton streaming in the solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MINOR IONS; HELIUM; ACCELERATION; HYDROGEN; SHOCK AB Data from the solar wind spectrometer on the Ulysses spacecraft are used to study the differential streaming between the alpha particles and protons in the solar wind over the heliographic distance range of 1.3 to 5.4 AU and latitudes from 0 degrees to +/- 80 degrees during the period December 1990 through September 1995. The study is based on 6-hour averages of the parameter V-alpha p = \V-alpha - V-p\ where V-alpha and V-p are the vector velocities of the alpha particles and protons, respectively. it is found that V-alpha p decreases with increasing distance from the Sun and with decreasing solar wind speed. The distance and velocity dependencies can be combined into a single dependence on travel time T from the Sun to the point of observation, with V-alpha p declining, on the average, as T--0.70+/-0.07. After normalization by this travel time factor, there is no residual dependence of V-alpha p on heliographic latitude thus ruling out any rotational effects on either the acceleration or deceleration of the alphas relative to the protons. There is also no significant difference in the normalized values of V-alpha p between quasi-stationary and transient (coronal mass ejection) flows. The ratios V-alpha p/V-wave where V-A is the Alfven speed, and V-alpha p/V-wave, where V-wave is the observed propagation speed of Alfvenic fluctuations, both decline with increasing distance from the Sun, but V-alpha p/V-wave remains in the range of 1.0 to 1.5 out to a travel time of 5 or 10 days. There are weak correlations between the normalized value of V-alpha p and the amplitudes of fluctuations in both the magnitude and the direction of the interplanetary magnetic field. Although V-alpha p anticorrelates strongly with the ratio of the Coulomb collision time to the solar wind expansion time, it is believed that the correlation is not evidence of a cause and effect relation between those two parameters over much of the solar wind regime observed by Ulysses. Where comparisons are possible, the Ulysses data closely agree with extrapolations of the Helios data to greater solar distances. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Neugebauer, M (reprint author), CALTECH,JET PROPULS LAB,PASADENA,CA, USA. NR 25 TC 59 Z9 59 U1 3 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1996 VL 101 IS A8 BP 17047 EP 17055 DI 10.1029/96JA01406 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VB700 UT WOS:A1996VB70000001 ER PT J AU GonzalezEsparza, JA Balogh, A Forsyth, RJ Neugebauer, M Smith, EJ Phillips, JL AF GonzalezEsparza, JA Balogh, A Forsyth, RJ Neugebauer, M Smith, EJ Phillips, JL TI Interplanetary shock waves and large-scale structures: Ulysses' observations in and out of the ecliptic plane SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; SOLAR-WIND STREAM; INTERACTION REGIONS; PLASMA OBSERVATIONS; OUTER HELIOSPHERE; SECTOR STRUCTURE; 1-AU; EVOLUTION; SOUTH; AU AB We present a study of 153 fast shock waves and their relation to other large-scale features in the solar wind: corotating interaction regions (CIRs), interplanetary counterparts of coronal mass ejections (ICMEs), and the magnetic sector structure, observed by Ulysses from October 1990 to the south solar polar pass in the summer of 1994. This is a comprehensive statistical study of interplanetary shock waves and their possible causes between 1 and 5.4 AU, in particular, out of the ecliptic. We identify six different heliographic intervals with distinct dynamic characteristics and shock wave populations (transient and corotating shocks). We present maps of large-scale features, which provide a general context to studies of particular events observed by Ulysses and a comparison of Ulysses observations with results from other missions. From our analysis of the associations between interplanetary shocks and their possible causes we find that I;he strongest in-ecliptic shock waves were leading CIRs about 4-5 AU. The strongest out-of-ecliptic shock waves were attributed to diverse causes at about 20 degrees south. We observed many quasi-parallel (theta(Bn) < 45 degrees) corotating shocks; in fact, most of the corotating reverse shocks detected during the in-ecliptic trajectory were quasi-parallel. The correlation between transient forward shocks and ICMEs (ejecta signatures) is similar to previous results within 1 AU: during the in-ecliptic trajectory Ulysses detected 25 ICMEs and 31 transient forward shocks, 13 of which were associated with ICMEs. The out-of-ecliptic results show an analogous correlation. After the Jupiter flyby we observed a significant number of nonrecurrent reverse shocks that do not show any association with ICMEs. This type of shock, instead of being driven by supermagnetosonic plasma clouds, might be produced by a different mechanism. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RI Gonzalez-Esparza, J. Americo/A-6720-2013 NR 45 TC 19 Z9 19 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1996 VL 101 IS A8 BP 17057 EP 17071 DI 10.1029/96JA00685 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VB700 UT WOS:A1996VB70000002 ER PT J AU Liewer, PC Karmesin, SR Brackbill, JU AF Liewer, PC Karmesin, SR Brackbill, JU TI Hydrodynamic instability of the heliopause driven by plasma-neutral charge-exchange interactions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID LOCAL INTERSTELLAR-MEDIUM; SOLAR-WIND; RADIO-EMISSION; TERMINATION SHOCK; HELIOSPHERE; INTERFACE; SYSTEM AB Results from time-dependent two-dimensional hydrodynamic simulations of the global heliosphere suggest that drag between the plasma ions and the interstellar neutrals, caused by charge-exchange collisions, may cause the heliopause to be hydrodynamically unstable. Both ions and neutrals are treated as fluids coupled by charge-exchange collisions. The neutral-ion drag is proportional to the plasma density and introduces an effective gravity in the direction of the neutral flow, which, because the interstellar plasma is much denser than the heliosheath plasma, causes a Rayleigh-Taylor-like instability to develop. The heliopause Is unstable only near the stagnation point at the ''nose'' of the heliosphere. In the simulations, the heliopause is seen to oscillate nonlinearly about its equilibrium position with a timescale of the order of a hundred years and amplitudes of tens of AUs. Growth rates from the Simulations are in reasonable agreement with theoretical estimates. The possible stabilizing influence of energetic solar wind neutrals, neglected in the present model, is discussed. Implications of this instability on the interpretation of the Voyager 2-3 kHz emissions are also discussed. C1 UNIV CALIF LOS ALAMOS NATL LAB T3,LOS ALAMOS,NM 87545. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP Liewer, PC (reprint author), CALTECH,PASADENA,CA 91125, USA. NR 21 TC 63 Z9 63 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1996 VL 101 IS A8 BP 17119 EP 17127 DI 10.1029/96JA00606 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VB700 UT WOS:A1996VB70000007 ER PT J AU Winske, D Omidi, N AF Winske, D Omidi, N TI A nonspecialist's guide to kinetic simulations of space plasmas SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID QUASI-PERPENDICULAR SHOCK; ION-ACOUSTIC INSTABILITY; HYBRID SIMULATIONS; ELECTRON DYNAMICS; PARTICLE CODE; 2-DIMENSIONAL SIMULATIONS; BOW SHOCKS; COLLISIONLESS; WAVES; MODEL AB The basic concepts involved in formulating and analyzing simulations of kinetic space plasmas are presented for readers with little background in simulation methods. Issues related to choosing the appropriate physics models and numerical algorithms, such as the correct representation for the plasma, proper description of the electromagnetic fields, geometric effects, initial and boundary conditions, and diagnostics, are discussed. Some of the strengths and limitations of the various approaches are also described. Explicit examples involving the simulation of collisionless shocks are presented to illustrate these points. Questions related to numerical accuracy and verification of the results are also examined and again illustrated through appropriate examples. C1 UNIV CALIF SAN DIEGO, ECE DEPT, LA JOLLA, CA 92093 USA. RP LOS ALAMOS NATL LAB, XPA, MAIL STOP B259, LOS ALAMOS, NM 87545 USA. NR 75 TC 49 Z9 49 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1996 VL 101 IS A8 BP 17287 EP 17303 DI 10.1029/96JA00982 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VB700 UT WOS:A1996VB70000020 ER PT J AU Than, C Morimoto, H Andres, H Williams, PG AF Than, C Morimoto, H Andres, H Williams, PG TI Tritium and deuterium labelling studies of alkali metal borohydrides and their application to simple reductions SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE lithium borohydride; sodium borohydride; potassium borohydride; tritiated borane; boron NMR; tritium NMR; deuterium NMR ID SODIUM-BOROHYDRIDE; ORGANIC-SYNTHESIS; SOLVENTS; UTILITY; AMINES AB Simple and facile syntheses of highly deuterated and tritiated LiBH4, NaBH4 and KBH4 were achieved by hydrogen isotope exchange with deuterium or tritium gas at elevated temperatures. The exchange products were characterized by boron, proton and deuterium or tritium NMR spectroscopy. The extent of isotope (H-2 or H-3) incorporation was calculated from the patterns of B-11 NMR spectra. Several samples of tritiated NaBH4 were treated with BF3-Et(2)O to produce tritiated borane-THF complex, which is an electrophilic reducing agent. The utility of both the borohydride reagents and borane-THF complex in labelling reactions was confirmed by exemplary reductions leading to specifically labelled products. The extent and orientation of labelling in the reduction products was assessed by a combination of radio-HPLC analysis, H-1, H-2 or H-3 NMR and mass spectrometry. C1 SANDOZ PHARMA LTD,CHEM RES & DEV,CH-4002 BASEL,SWITZERLAND. RP Than, C (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV BIOL STRUCT,NATL TRITIUM LABELLING FACIL,BERKELEY,CA 94720, USA. NR 55 TC 18 Z9 18 U1 0 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD AUG PY 1996 VL 38 IS 8 BP 693 EP 711 DI 10.1002/(SICI)1099-1344(199608)38:8<693::AID-JLCR883>3.0.CO;2-4 PG 19 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA UZ480 UT WOS:A1996UZ48000001 ER PT J AU Jaiswal, DK Morimoto, H Trump, EL Williams, PG Wemmer, DE AF Jaiswal, DK Morimoto, H Trump, EL Williams, PG Wemmer, DE TI Synthesis of high specific activity tritium labelled [2-H-3]-adenosine-5'-triphosphate SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE tritiodehalogenation; ATP; tritium gas; tritium NMR; HPLC ID SPECTROSCOPY AB A procedure for high level tritium labelling at the C2-H position of adenosine 5'-triphosphate ([2-H-3]-ATP, 1), based on the tritiodehalogenation reaction of 2-bromoadenosine 5'-triphosphate (2) has been elaborated. This precursor was prepared in a six-step synthesis from guanosine. The tritiodehalogenation of (2) for three hours over palladium oxide in phosphate buffer yielded tritium labelled ATP with high specific activity, in good chemical yield. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT BIOL STRUCT,BERKELEY,CA 94720. DEF RES & DEV ESTAB,GWALIOR 474002,INDIA. EMPORIA STATE UNIV,DIV PHYS SCI,EMPORIA,KS 66801. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF SAN FRANCISCO,DEPT PHARMACEUT CHEM,SAN FRANCISCO,CA 94143. RP Jaiswal, DK (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NATL TRITIUM LABELLING FACIL,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD AUG PY 1996 VL 38 IS 8 BP 743 EP 752 PG 10 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical; Pharmacology & Pharmacy SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA UZ480 UT WOS:A1996UZ48000005 ER PT J AU Fordham, EJ Mitra, PP Latour, LL AF Fordham, EJ Mitra, PP Latour, LL TI Effective diffusion times in multiple-pulse PFG diffusion measurements in porous media SO JOURNAL OF MAGNETIC RESONANCE SERIES A LA English DT Article ID NMR DIFFUSION; PROBE; COEFFICIENT; FLUIDS AB Expressions for the effective diffusion times in multiple-gradient pulse diffusion measurements in liquid-saturated porous media are derived. This is necessary since the diffusion coefficient is time dependent. The results are needed for quantitative interpretation of the results of PFG diffusion measurements using the multiple-alternating-gradient schemes which are preferred for the majority of porous systems. The essence of the calculation and the results for ''square'' and ''sine'' pulse shapes have appeared previously, but without derivation. The details of this somewhat technical calculation may be needed by users. (C) 1996 Academic Press, Inc. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11952. RP Fordham, EJ (reprint author), SCHLUMBERGER CAMBRIDGE RES LTD,MADINGLEY RD,CAMBRIDGE CB3 0HG,ENGLAND. NR 10 TC 31 Z9 32 U1 0 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1064-1858 J9 J MAGN RESON SER A JI J. Magn. Reson. Ser. A PD AUG PY 1996 VL 121 IS 2 BP 187 EP 192 DI 10.1006/jmra.1996.0159 PG 6 WC Physics, Atomic, Molecular & Chemical SC Physics GA VB314 UT WOS:A1996VB31400012 ER PT J AU Belk, MC Smith, MH AF Belk, MC Smith, MH TI Pelage coloration in oldfield mice (Peromyscus polionotus): Antipredator adaptation? SO JOURNAL OF MAMMALOGY LA English DT Article DE Peromyscus polionotus; crypsis; conspicuousness; pelage color; small mammals; predation ID SELECTION; PATTERNS AB Reflectance spectra (in full light and moonlight) of dorsal pelage of 469 adult oldfield mice (Peromyscus polionotus) comprising nine regional samples were compared to reflectance spectra of corresponding surface and subsurface soil samples to test for a selective effect of predation on color of pelage. Mice were slightly more reddish in hue, generally had more chroma, and were less reflective than soil at all locations. Color of pelage within locations was not significantly correlated with color of soil. Among all locations, brightness of pelage and soil were significantly positively cell-elated. Among mainland locations, there was a significant positive correlation between pelage and subsurface soil brightness. Difference between pelage color of mice and soil color (crypsis) did not differ between island and mainland locations. Regional patterns of variation in brightness of pelage provide support for the role of predation as a selective force affecting color of pelage in oldfield mice. However, variation in hue and chroma and differences in crypsis did not support a selective-predation hypothesis. C1 BRIGHAM YOUNG UNIV,DEPT ZOOL,PROVO,UT 84602. UNIV GEORGIA,SCH FOREST RESOURCES,INST ECOL,DEPT GENET,ATHENS,GA 30602. RP Belk, MC (reprint author), SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802, USA. NR 19 TC 18 Z9 18 U1 3 U2 52 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD AUG PY 1996 VL 77 IS 3 BP 882 EP 890 DI 10.2307/1382694 PG 9 WC Zoology SC Zoology GA VD373 UT WOS:A1996VD37300028 ER PT J AU Paul, BK Baskaran, S AF Paul, BK Baskaran, S TI Issues in fabricating manufacturing tooling using powder-based additive freeform fabrication SO JOURNAL OF MATERIALS PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT 12th International Conference on Computer Aided Production Engineering CY AUG 05-07, 1996 CL COOKEVILLE, TN DE rapid prototyping; freeform fabrication; powder issues; manufacturing tooling; benchmarking AB Recent interest has emerged for the development of ''tool-less'' processes capable of producing freeform geometries of metal and ceramic. One important application of such processes would be the rapid acquisition of manufacturing tooling including molds and dies. The basis of this paper is the review of additive freeform fabrication (AFF) processes that utilize particulate materials in processing freeform geometries. Current commercial AFF techniques include stereolithography, solid ground curing, selective laser sintering, fused deposition modeling, and laminated object manufacturing. Different approaches to direct metal or ceramic AFF using these processes have yielded a variety of results. The intent of the paper is to describe the various AFF techniques, summarize the powder processing capabilities of each, and identify some of the issues involved with applying these capabilities to manufacturing tooling. Equipment capabilities evaluated include speed, dimensional accuracy, surface roughness, material properties, work envelope, and cost. C1 PACIFIC NW NATL LAB, RICHLAND, WA 99352 USA. RP Paul, BK (reprint author), OREGON STATE UNIV, 118 COVELL HALL, CORVALLIS, OR 97330 USA. NR 18 TC 27 Z9 27 U1 3 U2 41 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0924-0136 J9 J MATER PROCESS TECH JI J. Mater. Process. Technol. PD AUG PY 1996 VL 61 IS 1-2 BP 168 EP 172 DI 10.1016/0924-0136(96)02482-X PG 5 WC Engineering, Industrial; Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA VD242 UT WOS:A1996VD24200026 ER PT J AU Taylor, DJ Dent, DZ Braski, DN Fabes, BD AF Taylor, DJ Dent, DZ Braski, DN Fabes, BD TI Boron loss in furnace- and laser-fired, sol-gel derived borosilicate glass films SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID INFRARED-ABSORPTION; SILICON; WATER AB Borosilicate glass films were made by the sol-gel method from tetraethoxysilane and trimethylborate precursors. The precursor or glass composition at each stage of processing was analyzed to determine the sources of boron loss. The films were heated in a furnace and with a laser to compare boron volatilization by the two heating methods. The films were characterized by infrared spectroscopy, ellipsometry, induction-charged plasma spectroscopy, and Auger microscopy. The highest losses of boron occurred during coating and low temperature (<500 degrees C) furnace firing. Films with the highest boron concentrations were made by dip coating and rapid firing, either with a laser or by placing them into a hot furnace. Infrared spectroscopy revealed Si-O-B bonds, indicating incorporation of boron into the borosilicate glass structure for laser- and furnace-fired films. C1 OAK RIDGE NATL LAB, HIGH TEMP MAT LAB, OAK RIDGE, TN 37831 USA. RP Taylor, DJ (reprint author), UNIV ARIZONA, DEPT MAT SCI & ENGN, TUCSON, AZ 85721 USA. NR 22 TC 12 Z9 13 U1 0 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1996 VL 11 IS 8 BP 1870 EP 1873 DI 10.1557/JMR.1996.0237 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA VB449 UT WOS:A1996VB44900004 ER PT J AU Odom, RW Grossbeck, ML AF Odom, RW Grossbeck, ML TI In-depth and ion image analysis of minor and trace constituents in V-Cr-Ti alloy welds SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SPECTROMETRY AB This paper describes the application of dynamic secondary ion mass spectrometry (SIMS) to the study of the chemistry of welds in V-Cr-Ti alloys and presents preliminary data on the distribution of minor and trace elements (H, C, N, O, P, S, and Cl) in welds produced by gas tungsten are (GTA) and electron beam techniques. The motivation for this research is to develop techniques that determine correlations between the concentration and distribution of trace elements in alloy metal welds and the physical properties of the weld. To this end, quantitative SIMS techniques were developed for N, O, and S analysis in vanadium alloy welds using an ion implantation/relative sensitivity factor methodology. The data presented in this paper demonstrate that trace compositions and distributions of selected welds correlate, at least qualitatively, with such properties as microhardness and tensile elongation. These data support continuing these investigations to develop microanalysis methods that quantitatively correlate weld composition with mechanical properties. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Odom, RW (reprint author), CHARLES EVANS & ASSOCIATES,REDWOOD CITY,CA 94063, USA. NR 18 TC 2 Z9 2 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1996 VL 11 IS 8 BP 1923 EP 1933 DI 10.1557/JMR.1996.0243 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA VB449 UT WOS:A1996VB44900010 ER PT J AU Lefevre, MJ Speck, JS Schwartz, RW Dimos, D Lockwood, SJ AF Lefevre, MJ Speck, JS Schwartz, RW Dimos, D Lockwood, SJ TI Microstructural development in sol-gel derived lead zirconate titanate thin films: The role of precursor stoichiometry and processing environment SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID TIME TEXTURE TRANSITION; INTRINSIC NONSTOICHIOMETRY; LIQUID PRECURSORS; PZT; CRYSTALLIZATION; CERAMICS; GROWTH AB The role of precursor stoichiometry and local firing environment on the microstructural development of sol-gel derived lead zirconate titanate (PZT) thin films was investigated. Typically, excess Pb is added to films to compensate for PbO volatilization during heat treatment. Here, it is shown that the use of stoichiometric precursors with either a PbO atmosphere powder or a PbO overcoat during the crystallization heat treatment is an attractive and viable alternative method for control of film stoichiometry. Using these approaches, we have fabricated single phase perovskite thin films with microstructures and electrical properties (P-r similar to 36 mu C/cm(2) and E(c) similar to 45 kV/cm) comparable to those of films using optimized solution chemistries and excess Pb additions. The potential advantage of increasing PbO partial pressure, or activity, during firing versus excess Pb additions is discussed from the standpoint of a proposed crystallization scenario based on the kinetic competition between Pb loss and the nucleation and growth rates of the perovskite phase. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Lefevre, MJ (reprint author), UNIV CALIF SANTA BARBARA,DEPT MAT,SANTA BARBARA,CA 93106, USA. RI Speck, James/H-5646-2011 NR 26 TC 77 Z9 77 U1 0 U2 14 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1996 VL 11 IS 8 BP 2076 EP 2084 DI 10.1557/JMR.1996.0261 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA VB449 UT WOS:A1996VB44900028 ER PT J AU Gao, Y Jia, J Loehman, RE Ewsuk, KG Fahrenholtz, WG AF Gao, Y Jia, J Loehman, RE Ewsuk, KG Fahrenholtz, WG TI Microstructure and composition of Al-Al2O3 composites made by reactive metal penetration SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID DIRECTED OXIDATION; ALUMINUM AB The microstructure of Al-Al2O3 composites made by reactive penetration of Al (or Al alloy) into ceramic (mullite or kaolin) preforms has been investigated using transmission electron microscopy (TEM). The Al-Al2O3 composites were found to contain a mutually-interconnected network of Al and Al2O3 NO crystallographic orientation was observed between the Al and Al2O3 phase. Impurities and pores in the ceramic preforms were found to have a strong effect on the microstructure of the composites. The impurities resulted in formation of small particles in the Al2O3 grains of Al-Al2O3 composites, whereas the porosity yielded a varied ratio of Al to Al2O3 in the composites. The growth rate of the Al-Al2O3 composites was found to depend on the microstructure and composition of the ceramic preforms as well as the composition of the reactive metals. Pure aluminium penetrated into a dense mullite faster than into a porous mullite at temperatures below 1200 degrees C. Addition of Mg to Al reduced the growth rate, whereas a continuous phase of amorphous SiO2 in the ceramic preforms increased the growth rate. C1 NEW MEXICO INST MIN & TECHNOL,DEPT MAT ENGN,SOCORRO,NM 87801. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. UNIV NEW MEXICO,ALBUQUERQUE,NM 87106. OI Fahrenholtz, William/0000-0002-8497-0092 NR 16 TC 10 Z9 12 U1 0 U2 1 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD AUG 1 PY 1996 VL 31 IS 15 BP 4025 EP 4032 DI 10.1007/BF00352664 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA VB331 UT WOS:A1996VB33100015 ER PT J AU Liu, HP Mitton, JB AF Liu, HP Mitton, JB TI Tissue-specific maternal and paternal mitochondrial DNA in the freshwater mussel, Anodonta grandis grandis SO JOURNAL OF MOLLUSCAN STUDIES LA English DT Article ID INHERITANCE; MYTILUS; HETEROPLASMY C1 UNIV COLORADO,DEPT ENVIRONM POPULAT & ORGANISM BIOL,BOULDER,CO 80309. RP Liu, HP (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0260-1230 J9 J MOLLUS STUD JI J. Molluscan Stud. PD AUG PY 1996 VL 62 BP 393 EP 394 DI 10.1093/mollus/62.3.393 PN 3 PG 2 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA VJ756 UT WOS:A1996VJ75600014 ER PT J AU Morimoto, Y Weeks, RA Magruder, RH Zuhr, RA AF Morimoto, Y Weeks, RA Magruder, RH Zuhr, RA TI Optical and electron paramagnetic resonance spectra of silica glass implanted with oxygen ions SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 13th University Conference on Glass Science - Optical and Electrical Properties of Glasses CY AUG 09-11, 1995 CL RENSSELAER POLYTECH INST, TROY, NY SP Amer Ceram Soc, Asahi Glass Fdn, Corning Inc, Heraeus Amersil Inc, Hoya Corp, Natl Sci Fdn, Nippon Elect Glass Co, Nippon Sheet Glass Co, USN, Off Naval Res, Schott Glass Technol Inc HO RENSSELAER POLYTECH INST AB Oxygen ions (O+) were implanted into high purity silica glass, Coming 7940, at liquid nitrogen temperature and at energies of 50, 160 keV and 5 MeV, with a dose range from 1 X 10(15) to 3 X 10(16) ions/cm(2). Helium ions (He+) were also implanted into Coming 7940 at liquid nitrogen temperature and at 35 keV and 160 keV to doses of 1 X 10(17) ions/cm(2) to compare with O+ implantation. Optical absorption measurements were made on the ion implanted samples in the range of 1.8 to 6.2 eV. In samples O+ implanted at 50 and 160 keV, the optical density at around 2.0 eV was zero, while the optical densities increased with increasing photon energy, and absorption bands at around 3, 5 and 5.8 eV were resolved. Absorption bands at. 5 and 5.8 eV were resolved in the 5 MeV implanted sample and their absorbencies were higher by factor of more than 2 than those in the 50 and 160 keV implanted samples. For He+ implanted samples optical density increased as a function of photon energy up to 6 eV, and in addition a band at 5 eV was resolved in every sample. X-band electron paramagnetic resonance (EPR) spectra were measured at 77 K for oxygen-related centers and at room temperature for E' centers prior to and after ion implantation of samples. Two paramagnetic states, E' centers and peroxy radicals, were detected after O+ or He+ implantation. The peroxy radical (FOR) was the dominant defect in O+ implanted samples, while the numbers of E' centers and PORs induced in He+ implanted samples were the same. Since the detected numbers of PORs were < 2% of the number of implanted O+, most of the implanted O+ must exist in forms which have not yet been detected in EPR measurements. The 5 eV band, assigned to PORs, increased with increasing oxygen dose and was also larger when the implant energy was 5 MeV. A reaction between E' centers and oxygen is proposed. C1 VANDERBILT UNIV,DEPT APPL & ENGN SCI,NASHVILLE,TN 37240. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 15 TC 10 Z9 10 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 AUG PY 1996 VL 203 BP 55 EP 61 DI 10.1016/0022-3093(96)00334-1 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA VL859 UT WOS:A1996VL85900009 ER PT J AU Morimoto, Y Weeks, RA Barnes, AV Tolk, NH Zuhr, RA AF Morimoto, Y Weeks, RA Barnes, AV Tolk, NH Zuhr, RA TI Electron dose dependence and oxygen implantation effect on cathodoluminescence intensity in synthetic silica glass SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 13th University Conference on Glass Science - Optical and Electrical Properties of Glasses CY AUG 09-11, 1995 CL RENSSELAER POLYTECH INST, TROY, NY SP Amer Ceram Soc, Asahi Glass Fdn, Corning Inc, Heraeus Amersil Inc, Hoya Corp, Natl Sci Fdn, Nippon Elect Glass Co, Nippon Sheet Glass Co, USN, Off Naval Res, Schott Glass Technol Inc HO RENSSELAER POLYTECH INST ID INDUCED LUMINESCENCE; AMORPHOUS SIO2; DEFECTS; CRYSTALLINE; QUARTZ; IONS AB A luminescence band at 2.75 eV in silica glass, Coming 7940, excited with 1 keV electron beam was measured as a function of beam current and dose. The initial luminescent intensities at 2.75 eV, taken within 1 s of the beginning of irradiation, were proportional to the beam current in the range 0.8 to 12.7 mu A/mm(2). The luminescent intensities as a function of dose were observed at current densities of 3.0, 4.8, and 12.7 mu A/mm(2). The intensities increased Linearly for doses < 0.1 C/cm(2) (the first stage) and the rate of growth decreased at that dose (the second stage) until the maximum intensity (the third stage). The intensity then decreased with increasing electron dose and did not recover (the fourth stage). Although the luminescent intensities differed for each beam current, the four stages were identical for these three current densities. We propose that these four stages are created by competition between generation and destruction of luminescent centers. We attribute the change in rate of increase, the subsequent maximum followed by the decrease to a loss of oxygen from the irradiated spot. Oxygen ion implantation was performed (dose of 3 X 10(16) ions/cm(2) at 50 keV) and the initial intensity of the 2.75 eV band on the first stage was enhanced by a factor of 8. The luminescence centers were created by oxygen ion implantation, therefore, the centers are related to oxygen. C1 VANDERBILT UNIV,DEPT APPL & ENGN SCI,NASHVILLE,TN 37240. VANDERBILT UNIV,DEPT PHYS & ASTRON,NASHVILLE,TN 37235. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 25 TC 17 Z9 17 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 AUG PY 1996 VL 203 BP 62 EP 68 DI 10.1016/0022-3093(96)00335-3 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA VL859 UT WOS:A1996VL85900010 ER PT J AU Anderson, TS Magruder, RH Weeks, RA Zuhr, RA AF Anderson, TS Magruder, RH Weeks, RA Zuhr, RA TI Effects of substrate temperature and nominal dose on the microstructure and optical properties of indium implanted high purity silica SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 13th University Conference on Glass Science - Optical and Electrical Properties of Glasses CY AUG 09-11, 1995 CL RENSSELAER POLYTECH INST, TROY, NY SP Amer Ceram Soc, Asahi Glass Fdn, Corning Inc, Heraeus Amersil Inc, Hoya Corp, Natl Sci Fdn, Nippon Elect Glass Co, Nippon Sheet Glass Co, USN, Off Naval Res, Schott Glass Technol Inc HO RENSSELAER POLYTECH INST ID ION-IMPLANTATION; FUSED-SILICA; GLASS; SILVER; GOLD AB Two series of nanometer dimension metal colloid-glass composites have been fabricated by ion implantation of In in high purity silica glass. One series was implanted at different substrate temperatures while holding the dose constant at 6x10(16) ions/cm(2). Substrate temperatures used were similar to 100, 273, 463 and 673 K. The second series was implanted with doses of 3, 6, 9, and 12 x 10(16) ions/cm(2) while holding the substrate temperature constant at 100 K. The properties of these series of samples were measured using backscattering transmission (RBS), transmission electron microscopy (TEM), and optical spectroscopy. RBS results show that a bimodal distribution of the ions occurs for all doses and substrate temperatures. TEM measurements show that spherical colloids are formed and the mean particle size is a function of nominal dose and substrate temperature during implantation. The colloids formed at the higher substrate temperature are amorphous while they have crystalline structure for the lower substrate temperature. The optical spectra exhibit a 1/lambda dependence with an absorption peak centered at similar to 260 nm due to the surface plasmon resonance of the In particles. The optical properties are also a function of nominal dose and substrate temperature during implantation. C1 VANDERBILT UNIV,DEPT APPL & ENGN SCI,NASHVILLE,TN 37240. OAK RIDGE NATL LAB,DIV SOLID STATE,SURFACE MODIFICAT & CHARACTERIZAT FACIL,OAK RIDGE,TN. NR 17 TC 15 Z9 15 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 AUG PY 1996 VL 203 BP 114 EP 119 DI 10.1016/0022-3093(96)00341-9 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA VL859 UT WOS:A1996VL85900018 ER PT J AU Sidebottom, DL Green, PF Brow, RK AF Sidebottom, DL Green, PF Brow, RK TI Scaling behavior in the conductivity of alkali oxide glasses, polymers, and doped crystals SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 13th University Conference on Glass Science - Optical and Electrical Properties of Glasses CY AUG 09-11, 1995 CL RENSSELAER POLYTECH INST, TROY, NY SP Amer Ceram Soc, Asahi Glass Fdn, Corning Inc, Heraeus Amersil Inc, Hoya Corp, Natl Sci Fdn, Nippon Elect Glass Co, Nippon Sheet Glass Co, USN, Off Naval Res, Schott Glass Technol Inc HO RENSSELAER POLYTECH INST ID DIELECTRIC RESPONSE; AC CONDUCTIVITY; RELAXATION AB Although the frequency dependent conductivity, sigma(omega) of ion-containing glasses displays power law dispersion (sigma(omega) approximate to omega(n)) that can usually be described by a master curve, several findings have suggested that this scaling fails at low temperatures as indicated by a temperature dependence of the scaling exponent, n. This behavior is investigated in the frequency range between 1 Hz and 10(6) Hz for different materials including alkali metaphophate glasses and a polymer. Two distinct regimes of conductive behavior, sigma(I) and sigma(II), are identified. The first, sigma(I), is strongly temperature dependent and appears to obey a master curve representation. The second, sigma(II), exhibits only a weak temperature dependence with a roughly linear frequency dependence. A strong depression of sigma(I) occurs for the mixed alkali case, but sigma(II) is unaffected and occurs at roughly the same location in all the alkali compositions studied. It is proposed that sigma(II) does not arise from cation motion, but rather originates from a second mechanism likely involving small distortions of the underlying glassy matrix. This assignment of sigma(II) is further supported by the approximately universal location of sigma(II), to within an order of magnitude, of a variety of materials, including a polymer electrolyte and doped crystal. Since sigma(I)(T) and sigma(II)(T approximate to const.) are viewed as separate phenomena, the temperature dependence of the scaling exponent is shown to result merely from a superposition of these two contributions and does not indicate any intrinsic failure of the scaling property of sigma(I). RP Sidebottom, DL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 18 TC 40 Z9 40 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 AUG PY 1996 VL 203 BP 300 EP 305 DI 10.1016/0022-3093(96)00362-6 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA VL859 UT WOS:A1996VL85900046 ER PT J AU Hasegawa, A Youngblood, GE Jones, RH AF Hasegawa, A Youngblood, GE Jones, RH TI Effect of irradiation on the microstructure of Nicalon fibers SO JOURNAL OF NUCLEAR MATERIALS LA English DT Letter ID SIC FIBERS; BEHAVIOR AB Microstructural analyses were performed by TEM on two types of Nicalon fibers (CG and Hi) after neutron irradiation at nominally 1040 degrees C to a relatively high dose (43 dpa). For comparison, microstructural analyses also were performed on unirradiated fibers that were thermally annealed at 1010 degrees C for a time equivalent to the irradiation exposure time. No grain growth was observed for either type of unirradiated, but thermally annealed Nicalon fibers. However, significant grain growth was observed to have taken place in the irradiated Nicalon-CG fiber, presumably irradiation induced. In contrast, no significant amount of grain growth was observed in the irradiated Hi-Nicalon fibers. Void and other irradiation defect structures were not observed in either fiber. For such extreme irradiation conditions (43 dpa at 1040 degrees C), the Hi-Nicalon fiber exhibits a much higher degree of microstructural stability than Nicalon-CG fiber. Composite SiC/SiC made with Hi-Nicalon promises to also exhibit improved irradiation performance. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Hasegawa, A (reprint author), TOHOKU UNIV, DEPT NUCL ENGN, AOBA KU, SENDAI, MIYAGI 98077, JAPAN. NR 13 TC 10 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PD AUG PY 1996 VL 231 IS 3 BP 245 EP 248 DI 10.1016/0022-3115(96)00387-X PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA VH538 UT WOS:A1996VH53800009 ER PT J AU Nakamura, Y Yoshino, R Pomphrey, N Jardin, SC AF Nakamura, Y Yoshino, R Pomphrey, N Jardin, SC TI Acceleration mechanism of vertical displacement event and its amelioration in tokamak disruptions SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE vertical displacement event; tokamak disruption; plasma pressure drop; plasma current quench; positional instability; tokamak simulation code; n-index; JT-60U tokamak; stabilizing shell; eddy currents; halo current AB Vertical displacement events (VDEs), which are frequently observed in disruptive discharges of elongated tokamaks, are investigated using the Tokamak Simulation Code. We show that disruption events such as a sudden plasma pressure drop (beta(p) collapse) and the subsequent plasma current quench (I-p quench) can accelerate VDEs due to the adverse destabilizing effect of the resistive shell, which has previously been thought to stabilize VDEs. In a tokamak with a surrounding shell which is asymmetric with respect to the geometric midplane, the I-p quench also causes an additional VDE acceleration due to the vertical imbalance of the attractive force. While the shell-geometry characterizes the VDE dynamics, the growth rate of VDEs depends strongly on the magnitude of the beta(p) collapse, the speed of the I-p quench and the n-index of the plasma equilibrium just before the disruption. An amelioration of I-p quench-induced VDEs was experimentally established in the JT-60U tokamak by optimizing the vertical location of the plasma just prior to the disruption. The JT-60U vacuum vessel is shown to be suitable for preventing the beta(p) collapse-induced VDE. C1 PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ 08543 USA. RP JAPAN ATOM ENERGY RES INST, NAKA FUS RES ESTAB, NAKA, IBARAKI 31101, JAPAN. RI Jardin, Stephen/E-9392-2010; pomphrey, neil/G-4405-2010 NR 21 TC 3 Z9 3 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0022-3131 EI 1881-1248 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD AUG PY 1996 VL 33 IS 8 BP 609 EP 619 DI 10.1080/18811248.1996.9731967 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VJ472 UT WOS:A1996VJ47200001 ER PT J AU Redmond, J Parker, G AF Redmond, J Parker, G TI Actuator placement based on reachable set optimization for expected disturbance SO JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS LA English DT Article DE vibration suppression; actuator placement; reachable set; optimization ID CONTROLLABILITY; SPACECRAFT AB This paper examines the role of the control objective and the control time in determining fuel-optimal actuator placement for structural control. A general theory is developed that can be easily extended to include alternative performance metrics such as energy and time-optimal control. The performance metric defines a convex admissible control set which leads to a max-min optimization problem expressing optimal location as a function of initial conditions and control time. A solution procedure based on a nested genetic algorithm is presented and applied to an example problem. Results indicate that the optimal placement varies widely as a function of both control time and disturbance location. An approximate fitness function is presented to alleviate the computational burden associated with finding exact solutions. This function is shown to accurately predict the optimal actuator locations for a 6th-order system, and is further demonstrated on a 12th-order system. RP Redmond, J (reprint author), SANDIA NATL LABS,STRUCT DYNAM & VIBRAT CONTROL DEPT,TECH STAFF,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 19 TC 8 Z9 8 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-3239 J9 J OPTIMIZ THEORY APP JI J. Optim. Theory Appl. PD AUG PY 1996 VL 90 IS 2 BP 279 EP 300 DI 10.1007/BF02189999 PG 22 WC Operations Research & Management Science; Mathematics, Applied SC Operations Research & Management Science; Mathematics GA UZ768 UT WOS:A1996UZ76800003 ER PT J AU Berges, JA Falkowski, PG AF Berges, JA Falkowski, PG TI Cell-associated proteolytic enzymes from marine phytoplankton SO JOURNAL OF PHYCOLOGY LA English DT Article DE Clp protease; enzyme activity; marine phytoplankton; pH optima; protein degradation; protease inhibitors; proteases ID CHLAMYDOMONAS-REINHARDTII; PROTEINS; PURIFICATION; AMINOPEPTIDASE; PROTEASES; LEAVES; CHLOROPLASTS; DEGRADATION; CYANOBACTERIA; LIMITATION AB Despite their central importance in cell metabolism, little is known about proteases in marine phytoplankton. We surveyed caseinolytic and leucine aminopeptidase (LAP) activities in log-phase cultures of the chlorophyte Dunaliella tertiolecta Butcher, the diatom Thalassiosira weissflogii (Gru.) Fryxell et Hasle, the chrysophyte Isochrysis galbana Parke, the coccolithophorid Emiliania huxleyi (Lohm.) Hay et Mohler, and the cyanobacterium Synechococcus sp. (WH 5701). LAP activity was very low at pH < 6 and peaked between pH 7.5 and 8.5 in all species, whereas caseinolytic activity in most species showed only minor peaks in the pH 4-5 range and broad maxima above pH 8. Thus, acidic vacuolar proteases apparently represented only a small fraction of total protease activity. Attempts to classify proteases using selective inhibitors were inconclusive. Neither the serine/cysteine protease inhibitor leupeptin nor the aspartic protease inhibitor pepstatin A inhibited caseinolytic or LAP activity in any species. The metalloprotease inhibitor EDTA was only effective against LAP activity in some species, causing average decreases of 30-50%, whereas the cysteine/serine protease inhibitor phenyl methyl sulfonyl fluoride achieved at best a 30-60% decrease in caseinolytic activity. Caseinolytic activities were remarkably stable. At pH 7.5 and 25 degrees C, extracts of D. tertiolecta, E. huxleyi, and Synechococcus showed no changes in activity after 24 h, whereas activity declined by less than 50% in the other species. Incubation of cell extracts for 1 h at 25 degrees C in pH 7.5 buffer did not alter patterns of cell proteins, suggesting that endogenous proteases did not effectively degrade endogenous proteins. Casein zymograms were used to identify >200-and <20-kDa proteases in homogenates of log-phase T. weissflogii; only the smaller protease was found in D. tertiolecta. Antibodies to the ATPase subunit (C) of the conserved, chloroplastic Clp protease from Pisum cross-reacted wit proteins in Synechococcus, D. tertiolecta, and I. galbana, but no cross-reactions were found for any species with antibodies against the ClpP subunit from either E. coli or Nicotiana. Our results show that phytoplankton contain a diverse complement of proteases with novel characteristics. C1 BROOKHAVEN NATL LAB, DIV OCEANOG & ATMOSPHER SCI, UPTON, NY 11973 USA. RI Berges, John /D-9520-2012 OI Berges, John /0000-0002-3124-4783 NR 46 TC 28 Z9 28 U1 0 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0022-3646 EI 1529-8817 J9 J PHYCOL JI J. Phycol. PD AUG PY 1996 VL 32 IS 4 BP 566 EP 574 DI 10.1111/j.0022-3646.1996.00566.x PG 9 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA VD568 UT WOS:A1996VD56800009 ER PT J AU Truhlar, DG Garrett, BC Klippenstein, SJ AF Truhlar, DG Garrett, BC Klippenstein, SJ TI Current status of transition-state theory SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Review ID ACTIVATED-RATE-PROCESSES; POTENTIAL-ENERGY SURFACES; CHEMICAL-REACTION RATES; PROTON-TRANSFER REACTIONS; CUMULATIVE REACTION PROBABILITIES; THERMAL RATE CONSTANTS; AB-INITIO DYNAMICS; PHASE-SPACE THEORY; MECHANICAL RATE CONSTANTS; DENSITY-FUNCTIONAL THEORY AB We present an overview of the current status of transition-state theory and its generalizations. We emphasize (i) recent improvements in available methodology for calculations on complex systems, including the interface with electronic structure theory, (ii) progress in the theory and application of transition-state theory to condensed-phase reactions, and (iii) insight into the relation of transition-state theory to accurate quantum dynamics and tests of its accuracy via comparisons with both experimental and other theoretical dynamical approximations. C1 UNIV MINNESOTA, INST SUPERCOMP, MINNEAPOLIS, MN 55455 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. CASE WESTERN RESERVE UNIV, DEPT CHEM, CLEVELAND, OH 44106 USA. RP UNIV MINNESOTA, DEPT CHEM, MINNEAPOLIS, MN 55455 USA. RI Garrett, Bruce/F-8516-2011; Truhlar, Donald/G-7076-2015; OI Truhlar, Donald/0000-0002-7742-7294; Klippenstein, Stephen/0000-0001-6297-9187 NR 841 TC 1096 Z9 1105 U1 32 U2 264 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 1 PY 1996 VL 100 IS 31 BP 12771 EP 12800 DI 10.1021/jp953748q PG 30 WC Chemistry, Physical SC Chemistry GA VA595 UT WOS:A1996VA59500008 ER PT J AU Butler, LJ Neumark, DM AF Butler, LJ Neumark, DM TI Photodissociation dynamics SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Review ID INTERNAL ENERGY-DISTRIBUTION; LASER-INDUCED FLUORESCENCE; INTRAMOLECULAR VIBRATIONAL REDISTRIBUTION; ENHANCED MULTIPHOTON IONIZATION; PRODUCT-STATE DISTRIBUTIONS; PHOTOFRAGMENT TRANSLATIONAL SPECTROSCOPY; RESOLVED FTIR EMISSION; 1ST ABSORPTION-BAND; VECTOR CORRELATIONS; PHOTO-DISSOCIATION AB Advances in the study of photodissociation dynamics over the past 30 years are reviewed. An overview of experimental techniques that have been developed to extract photofragment energy and angular distributions is presented, followed by a discussion on several current topics of interest in the field of photodissociation. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637. RP Butler, LJ (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 214 TC 81 Z9 83 U1 1 U2 32 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 1 PY 1996 VL 100 IS 31 BP 12801 EP 12816 DI 10.1021/jp953518b PG 16 WC Chemistry, Physical SC Chemistry GA VA595 UT WOS:A1996VA59500009 ER PT J AU Moore, GB Smith, IWM AF Moore, GB Smith, IWM TI State-resolved studies of reactions in the gas phase SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Review ID POTENTIAL-ENERGY SURFACE; DIFFERENTIAL CROSS-SECTIONS; INDUCED FLUORESCENCE DETERMINATION; PHOTOFRAGMENT YIELD SPECTROSCOPY; UNIMOLECULAR REACTION DYNAMICS; FLEXIBLE TRANSITION-STATES; HIGH COLLISION ENERGIES; VIBRATIONAL-EXCITATION; DISSOCIATION THRESHOLD; RATE CONSTANTS AB During the first years of The Journal of Physical Chemistry, chemists were just beginning to understand chemical reactions in gases as sequences of elementary reaction steps. Basic models of reaction dynamics were developed in succeeding decades which provided powerful qualitative insight into reaction mechanisms and rate constants. In recent decades, the development of molecular beam and laser technologies has allowed us to look into the transition state region at the dynamics of chemical bond formation and breaking. State-selective preparation of reactants and state-resolved detection of products with velocity and angle resolution permit exacting quantitative test of dynamical theories. Thanks to the ability to calculate accurate nb initio potential energy surfaces and solve Schroedinger's equation for reactive scattering dynamics, the simplest reactions are now understood quantitatively at the most fundamental level possible. The concepts and models thus developed, along with ever more powerful experimental and computational tools, are rapidly being applied to more complex reactions. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. UNIV BIRMINGHAM, SCH CHEM, BIRMINGHAM B15 2TT, W MIDLANDS, ENGLAND. RP UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. NR 224 TC 4 Z9 4 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 1 PY 1996 VL 100 IS 31 BP 12848 EP 12865 PG 18 WC Chemistry, Physical SC Chemistry GA VA595 UT WOS:A1996VA59500012 ER PT J AU Nozik, AJ Memming, R AF Nozik, AJ Memming, R TI Physical chemistry of semiconductor-liquid interfaces SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Review ID SOLAR-ENERGY CONVERSION; HETEROGENEOUS PHOTOCATALYTIC OXIDATION; MATCHED SUPERLATTICE ELECTRODES; HOT CARRIER INJECTION; PHOTOELECTROCHEMICAL CELLS; QUANTUM-WELLS; EFFICIENT SOLAR; PHOTOASSISTED ELECTROLYSIS; ARTIFICIAL PHOTOSYNTHESIS; PHOTOCURRENT SPECTROSCOPY AB The science describing semiconductor-liquid interfaces is highly interdisciplinary, broad in scope, interesting, and of importance to various emerging technologies. We present a review of the basic physicochemical principles of semiconductor-liquid interfaces, including their historical development, and describe the major technological applications that are based on these scientific principles. C1 INST SOLARENERGIE FORSCH GMBH HANNOVER,D-30165 HANNOVER,GERMANY. RP Nozik, AJ (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 205 TC 555 Z9 561 U1 18 U2 210 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 1 PY 1996 VL 100 IS 31 BP 13061 EP 13078 DI 10.1021/jp953720e PG 18 WC Chemistry, Physical SC Chemistry GA VA595 UT WOS:A1996VA59500027 ER PT J AU HeadGordon, M AF HeadGordon, M TI Quantum chemistry and molecular processes SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID DENSITY-FUNCTIONAL THERMOCHEMISTRY; ELECTRON CORRELATION; EXCHANGE; DYNAMICS; HYPERPOLARIZABILITIES; SIMULATIONS AB This article gives an overview of modem electronic structure theory, which is the development of approximate quantum mechanical methods for calculating the ground and excited electronic states of molecules. A series of seven topics are discussed which have contributed to the present state of the field and that illustrate in a general way some of the essential physical models and approximations that underpin electronic structure calculations. These topics begin from the definition of theoretical model chemistries and the treatment of electron correlation by wave function-based techniques and density functional theory, for both molecular energies and a range of molecular properties. Beyond these main theoretical issues, questions of chemical interpretation, computational algorithms, and the modeling of surrounding environment are also discussed. Collectively these topics define many of the classes of chemical problems which can be reliably and feasibly solved by such calculations at present, and conversely they also serve to define a number of unresolved challenges for the future. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP HeadGordon, M (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 83 TC 174 Z9 174 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 1 PY 1996 VL 100 IS 31 BP 13213 EP 13225 DI 10.1021/jp953665+ PG 13 WC Chemistry, Physical SC Chemistry GA VA595 UT WOS:A1996VA59500037 ER PT J AU Alivisatos, AP AF Alivisatos, AP TI Perspectives on the physical chemistry of semiconductor nanocrystals SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CDSE QUANTUM DOTS; SOLID PHASE-TRANSITION; X-RAY PHOTOELECTRON; SIZE DEPENDENCE; MELTING TEMPERATURE; POROUS SILICON; OPTICAL-PROPERTIES; ELECTRONIC STATES; ROOM-TEMPERATURE; PHONON COUPLINGS AB Semiconductor nanocrystals exhibit a wide range of size-dependent properties. Variations in fundamental characteristics ranging from phase transitions to electrical conductivity can be induced by controlling the size of the crystals, The present status and new opportunities for research in this area of materials physical chemistry are reviewed. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY NATL LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. RI Alivisatos , Paul /N-8863-2015 OI Alivisatos , Paul /0000-0001-6895-9048 NR 93 TC 2667 Z9 2718 U1 56 U2 610 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 1 PY 1996 VL 100 IS 31 BP 13226 EP 13239 DI 10.1021/jp9535506 PG 14 WC Chemistry, Physical SC Chemistry GA VA595 UT WOS:A1996VA59500038 ER PT J AU Tycko, R Reimer, JA AF Tycko, R Reimer, JA TI Optical pumping in solid state nuclear magnetic resonance SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID LASER-POLARIZED XE-129; GAAS QUANTUM-WELLS; HIGH-PURITY GAAS; SPIN-EXCHANGE; CROSS-POLARIZATION; GALLIUM-ARSENIDE; ELECTRONIC-PROPERTIES; ALKALI FULLERIDES; POLYMER SURFACE; PUMPED XENON AB An important current trend in solid state nuclear magnetic resonance (NMR) is the growing exploitation of optical pumping of nuclear spin polarizations as a means of enhancing and localizing NMR signals. Recent work has been concentrated in two areas, namely optically pumped NMR in semiconductors and optical pumping of noble gases. Progress in these two areas, including technical developments and new applications in physical chemistry, condensed matter physics, and biomedical sciences, is reviewed. Likely directions for future developments are suggested. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. RP Tycko, R (reprint author), NIDDKD,CHEM PHYS LAB,NIH,BETHESDA,MD 20892, USA. NR 74 TC 57 Z9 57 U1 4 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 1 PY 1996 VL 100 IS 31 BP 13240 EP 13250 DI 10.1021/jp953667u PG 11 WC Chemistry, Physical SC Chemistry GA VA595 UT WOS:A1996VA59500039 ER PT J AU Tinoco, I AF Tinoco, I TI Nucleic acid structures, energetics, and dynamics SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Review ID SINGLE DNA-MOLECULES; STRANDED DUPLEX DNA; RNA DOUBLE HELIX; FIELD GEL-ELECTROPHORESIS; OXYTRICHA TELOMERIC DNA; RIBOSOMAL-RNA; 3-DIMENSIONAL STRUCTURE; BASE-PAIRS; SEQUENCE DEPENDENCE; HAMMERHEAD RIBOZYME AB In 1953 DNA was shown to be a double helix of hydrogen-bonded complementary bases. Since then, knowledge of nucleic acid structures, thermodynamic stabilities, and dynamics of conformational changes has grown exponentially. This knowledge has led to the development of the biotechnology industry, the identification of plants and animals from a few cells, and many advances in the diagnosis and treatment of diseases. All the methods of physical chemistry have been used to characterize the primary structures (sequences), the secondary structures (base pairing), and the tertiary structures (folded 3D conformations) of the nucleic acids. The interactions of nucleic acids with themselves, with proteins, and with small-molecule ligands control their many functions, Novel methods are being developed to probe the structures and functions of nucleic acids. These include methods to study a single molecule and methods to select, amplify, and characterize one sequence among 10(17) different sequences. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY NATL LAB, DIV STRUCT BIOL, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. NR 156 TC 30 Z9 30 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 1 PY 1996 VL 100 IS 31 BP 13311 EP 13322 DI 10.1021/jp953053p PG 12 WC Chemistry, Physical SC Chemistry GA VA595 UT WOS:A1996VA59500044 ER PT J AU Haider, Q Liu, LC AF Haider, Q Liu, LC TI A mesonic model of rho-baryon-baryon vertices SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID VERTEX FORM-FACTORS; PI-N SCATTERING; EXCHANGE MODEL; NUCLEON SCATTERING; CHARGE-EXCHANGE; DELTA; DISTRIBUTIONS AB The coupling constants and form factors of the rho NN, rho N Delta and rho Delta Delta vertices are studied with a composite model. These form factors satisfy a set of coupled integral equations with the Born amplitudes and higher-order interactions dominated, respectively, by two-pion intermediate states and pi-loop corrections to the vertices. Upon solving the relevant equations self-consistently, we found that the loop corrections are unimportant for the rho NN vertex but quite significant for the rho N Delta and rho Delta Delta vertices. With the known values of pi-baryon, omega-baryon, rho pi pi and rho omega pi coupling constants as inputs, the model predicts a f(rho NN) compatible with that given by the meson-exchange potentials, but a slightly weaker f(rho N Delta). The composite model also predicts soft rho-baryon-baryon form factors having a momentum-space range between 400 and 500 MeV c(-1), in agreement with other recent theoretical findings. We discuss the implications of our findings on nuclear reaction studies. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Haider, Q (reprint author), FORDHAM UNIV,DEPT PHYS,BRONX,NY 10458, USA. NR 43 TC 6 Z9 7 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD AUG PY 1996 VL 22 IS 8 BP 1187 EP 1214 DI 10.1088/0954-3899/22/8/008 PG 28 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA VC651 UT WOS:A1996VC65100008 ER PT J AU Uras, RA AF Uras, RA TI Use of a viscoelastic model for the seismic response of base-isolated buildings SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Due to recent developments in elastomer technology seismic isolation using elastomer bearings is rapidly becoming an acceptable design tool to enhance structural seismic margins and to protect people and equipment from earthquake damage. With proper design of isolators, high-energy seismic input motions can be transformed into low-frequency, low-energy harmonic motions, and the accelerations acting on the isolated building may be significantly reduced. Several alternatives exist for the modeling of the isolators. This study is concerned with the use of a viscoelastic model to produce the seismic response of base-isolated buildings. The in-house finite element computer code, SISEC has been modified to incorporate a viscoelastic spring element, and several simulations are performed. Then, the computed results have been compared with the corresponding observed data recorded at the test facility. RP Uras, RA (reprint author), ARGONNE NATL LAB,REACTOR ENGN DIV,9700 S CASS AVE,BLDG 208,ARGONNE,IL 60439, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD AUG PY 1996 VL 118 IS 3 BP 374 EP 383 DI 10.1115/1.2842203 PG 10 WC Engineering, Mechanical SC Engineering GA VD533 UT WOS:A1996VD53300016 ER PT J AU Jenkins, D Winston, R Bliss, J OGallagher, J Lewandowski, A Bingham, C AF Jenkins, D Winston, R Bliss, J OGallagher, J Lewandowski, A Bingham, C TI Solar concentration of 50,000 achieved with output power approaching 1 kW SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID PERFORMANCE; SUN AB We have achieved a 50,000 +/- 3,000 times concentration of sunlight using a unique dielectric nonimaging concentrator in an experiment performed at the National Renewable Energy Laboratory. The scale of the experiment is several times larger than that of previous experiments. Total output power approaching 1 kW passes through a 4.6 mm diameter aperture. An extractor tip is added to the concentrator profile which allows measurement of flux levels using an air calorimeter, This new device has the potential to allow the use of dielectric concentrators at larger scale for thermal electric power generation. We report on the implications of this experiment for the future use of dielectric concentrators. C1 UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. NATL RENEWAL ENERGY LAB,GOLDEN,CO 80401. NR 11 TC 8 Z9 11 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD AUG PY 1996 VL 118 IS 3 BP 141 EP 145 DI 10.1115/1.2870882 PG 5 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA VD785 UT WOS:A1996VD78500001 ER PT J AU James, GH Carne, TG Veers, PS AF James, GH Carne, TG Veers, PS TI Damping measurements using operational data SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB We have measured modal damping using strain-gauge data from an operating wind turbine. This new technique for measuring modal damping is easier and less expensive than previously used methods. Auto-correlation and crass-can elation functions of the strain-gauge data have been shown to consist of decaying sinusoids which correspond to the modal frequencies and damping ratios of the wind turbine. We have verified the method by extracting damping values from an analytically generated data set. Actual operating response data from the DOE/Sandia 34-m Test Bed has been used to calculate modal clamping ratios as a function of rotor rotation rate. This capability will allow more accurate fatigue life prediction and control. RP James, GH (reprint author), SANDIA NATL LABS,EXPTL STRUCT DYNAM TESTING,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 16 TC 8 Z9 9 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD AUG PY 1996 VL 118 IS 3 BP 190 EP 193 DI 10.1115/1.2870943 PG 4 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA VD785 UT WOS:A1996VD78500009 ER PT J AU Ho, PC Palmer, DA AF Ho, PC Palmer, DA TI Ion association of dilute aqueous sodium hydroxide solutions to 600 degrees C and 300 MPa by conductance measurements SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE conductivity; aqueous; sodium hydroxide; ion association; temperature; pressure ID HIGH-TEMPERATURES; WATER; CONDUCTIVITY; PRESSURES; 0-DEGREES-C AB The limiting molar conductances Lambda(o) and ion association constants of dilute aqueous NaOH solutions (< 0.01 mol-kg(-1)) were determined by electrical conductance measurements at temperatures from 100 to 600 degrees C and pressures up to 300 MPa. The limiting molar conductances of NaOH(aq) were found to increase with increasing temperature up to 300 degrees C and with decreasing water density rho(w). At temperatures greater than or equal to 400 degrees C, and densities between 0.6 to 0.8 g-cm(-3). Lambda(o) is nearly temperature-independent but increases linearly with decreasing density, and then decreases at densities <0.6 g-cm(-3). This phenomenon is largely due to the breakdown of the hydrogen-bonded structure of water The molal association constants K-Am for NaOH(aq) increase with increasing temperature and decreasing density. The logarithm of the moiai nssncialion consrant can be represenred os a function of temperature (Kelvin) and the logarithm of the density of water by log K-Am = 2.477 - 951.53/T - (9.307 - 3482.8/T)log rho(w) (25-600 degrees C) which includes selected data taken from the literature, or by log K-Am = 1.648 - 370.31/T - (13.215 - 6300.5/T)log rho(w) (400-600 degrees C) which is based solely,on results from the present study over this temperature range (and to 300 MPa) where the measurements are most precise. RP Ho, PC (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 32 TC 72 Z9 74 U1 1 U2 7 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD AUG PY 1996 VL 25 IS 8 BP 711 EP 729 DI 10.1007/BF00973780 PG 19 WC Chemistry, Physical SC Chemistry GA VK385 UT WOS:A1996VK38500001 ER PT J AU Johnston, DC Chou, FC Borsa, F Carretta, P Lascialfari, A Gooding, RJ Salem, NM Vos, KJE Cho, JH Torgeson, DR AF Johnston, DC Chou, FC Borsa, F Carretta, P Lascialfari, A Gooding, RJ Salem, NM Vos, KJE Cho, JH Torgeson, DR TI Phase separation kinetics in La2CuO4+delta and inhomogeneous hole doping in the antiferromagnetic regime(03.3.CO;2-C PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA VB996 UT WOS:A1996VB99600006 ER PT J AU Richardson, TJ Ross, PN AF Richardson, TJ Ross, PN TI FTIR spectroscopy of metal oxide insertion electrodes: Thermally induced phase transitions in LixMn2O4 spinels SO MATERIALS RESEARCH BULLETIN LA English DT Article DE oxides; infrared spectroscopy; energy storage; phase transitions ID MANGANESE-DIOXIDE; LITHIUM; LIMN2O4; EXTRACTION AB LixMn2O4 spinels with x = 0.1, 1.0 and 2.0 were examined by Fourier transform infrared spectroscopy at temperatures ranging from -150 to 250 degrees C. The occurrence of a reversible phase transition near 10 degrees C in LiMn2O4 was confirmed. The thermal decomposition of Li0.1Mn2O4 to beta-MnO2 was studied as a function of time and temperature. The instability of this material in its charged state raises some concern about its viability in rechargeable lithium cells. RP Richardson, TJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 13 TC 32 Z9 33 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0025-5408 J9 MATER RES BULL JI Mater. Res. Bull. PD AUG PY 1996 VL 31 IS 8 BP 935 EP 941 DI 10.1016/S0025-5408(96)00079-7 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA UZ373 UT WOS:A1996UZ37300006 ER PT J AU More, JJ AF More, JJ TI Global methods for nonlinear complementarity problems SO MATHEMATICS OF OPERATIONS RESEARCH LA English DT Article DE nonlinear complementarity; nonlinear least squares; convergence ID TRUST REGION ALGORITHMS; NONSMOOTH NEWTON METHOD; VARIATIONAL-INEQUALITIES; CONTINUATION METHOD; OPTIMIZATION PROBLEMS; SIMPLE BOUNDS; CONVERGENCE; EQUATIONS; MINIMIZATION; CONSTRAINTS AB Global methods for nonlinear complementarity problems formulate the problem as a system of nonsmooth nonlinear equations, or use continuation to trace a path defined by a smooth system of nonlinear equations. We formulate the nonlinear complementarity problem as a bound-constrained nonlinear least squares problem. Algorithms based on this formulation are applicable to general nonlinear complementarity problems, can be started from any nonnegative starting point, and each iteration only requires the solution of systems of linear equations. Convergence to a solution of the nonlinear complementarity problem is guaranteed under reasonable regularity assumptions. The converge rate is e-linear, e-superlinear, or a-quadratic, depending on the tolerances used to solve the subproblems. RP More, JJ (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 51 TC 44 Z9 46 U1 0 U2 0 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 SN 0364-765X J9 MATH OPER RES JI Math. Oper. Res. PD AUG PY 1996 VL 21 IS 3 BP 589 EP 614 DI 10.1287/moor.21.3.589 PG 26 WC Operations Research & Management Science; Mathematics, Applied SC Operations Research & Management Science; Mathematics GA VV423 UT WOS:A1996VV42300006 ER PT J AU Fahrenholtz, WG Ewsuk, KG Loehman, RE Tomsia, AP AF Fahrenholtz, WG Ewsuk, KG Loehman, RE Tomsia, AP TI Formation of structural intermetallics by reactive metal penetration of Ti and Ni oxides and aluminates SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on In Situ Reactions for Synthesis of Composites, Ceramics, and Intermetallics, at the 124th TMS Annual Meeting CY FEB 12-16, 1995 CL LAS VEGAS, NV SP ASM MSD, SMD Composites Comm, Minerals Met & Mat Soc, MDMD Powder Mat Comm AB Alumina-aluminum composites can be prepared by reactive metal penetration (RMP) of mullite by aluminum. The process is driven by a strong negative free energy for the reaction (8 + x)Al + 3Al(6)Si(2)O(13) --> 13Al(2)O(3) + 6Si + xAl. Thermodynamic calculations reveal that titanium oxide, aluminum titanate, nickel oxide, and nickel aluminate all have a negative free energy of reaction with aluminum from 298 to 1800 K, indicating that it may be possible to form alumina-intermetallic composites by reactions of the type (2 + x)Al + (3/y) MO(y) --> Al2O3 + Al(x)M(3/y). Experiments revealed that aluminum reacts with titanium oxide, nickel oxide, and nickel aluminate, but not aluminum titanate, at 1673 K. Reaction with the stoichiometric amount of aluminum (x = 0) leads to the formation of alumina and either titanium or nickel. In some cases, reactions with excess aluminum (x > 0) produce intermetallic compounds such as TiAl3 and NiAl. C1 SANDIA NATL LABS,TECH STAFF,ALBUQUERQUE,NM 87106. SANDIA NATL LABS,UNIV PROGRAMS & ADV MAT DEPT,ALBUQUERQUE,NM 87106. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Fahrenholtz, WG (reprint author), UNIV NEW MEXICO,DEPT CHEM & NUCL ENGN,ALBUQUERQUE,NM 87106, USA. OI Fahrenholtz, William/0000-0002-8497-0092 NR 10 TC 20 Z9 20 U1 0 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD AUG PY 1996 VL 27 IS 8 BP 2100 EP 2104 DI 10.1007/BF02651864 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VC633 UT WOS:A1996VC63300006 ER PT J AU Ewsuk, KG Glass, SJ Loehman, RE Tomsia, AP Fahrenholtz, WG AF Ewsuk, KG Glass, SJ Loehman, RE Tomsia, AP Fahrenholtz, WG TI Microstructure and properties of Al2O3-Al(Si) and Al2O3-Al(Si)-Si composites formed by in situ reaction of Al with aluminosilicate ceramics SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on In Situ Reactions for Synthesis of Composites, Ceramics, and Intermetallics, at the 124th TMS Annual Meeting CY FEB 12-16, 1995 CL LAS VEGAS, NV SP ASM MSD, SMD Composites Comm, Minerals Met & Mat Soc, MDMD Powder Mat Comm ID METAL INFILTRATION; TOUGHNESS AB Al2O3-Al(Si) and Al2O3-Al(Si)-Si composites have been formed by in situ reaction of molten Al with aluminosilicate ceramics. This reactive metal penetration (RMP) process is driven by a strongly negative Gibbs energy for reaction, In the Al/mullite system, Al reduces mullite to produce alpha-Al2O3 and elemental Si, With excess Al (i.e., x > 0), a composite of alpha-Al2O3, Al(Si) alloy, and Si can be formed. Ceramic-metal composites containing up to 30 vol pct Al(Si) were prepared by reacting molten Al with dense, aluminosilicate ceramic preforms or by reactively hot pressing Al and mullite powder mixtures. Both reactive metal-forming techniques produce ceramic composite bodies consisting of a fine-grained alumina skeleton with an interpenetrating Al(Si) metal phase. The rigid alumina ceramic skeletal structure dominates composite physical properties such as the Young's modulus, hardness, and the coefficient of thermal expansion, while the interpenetrating ductile Al(Si) metal phase contributes to composite fracture toughness. Microstructural analysis of composite fracture surfaces shows evidence of ductile metal failure of Al(Si) ligaments, Al2O3-Al(Si) and Al2O3-Al(Si)-Si composites produced by in situ reaction of aluminum with mullite have improved mechanical properties and increased stiffness relative to dense mullite, and composite fracture toughness increases with increasing Al(Si) content. C1 SANDIA NATL LABS,UNIV PROGRAMS & ADV MAT LAB,ALBUQUERQUE,NM 87185. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV NEW MEXICO,DEPT CHEM & NUCL ENGN,ALBUQUERQUE,NM 87106. RP Ewsuk, KG (reprint author), SANDIA NATL LABS,TECH STAFF,POB 5800,ALBUQUERQUE,NM 87185, USA. OI Fahrenholtz, William/0000-0002-8497-0092 NR 26 TC 30 Z9 31 U1 1 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD AUG PY 1996 VL 27 IS 8 BP 2122 EP 2129 DI 10.1007/BF02651867 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VC633 UT WOS:A1996VC63300009 ER PT J AU Abraham, DP McDeavitt, SM Park, J AF Abraham, DP McDeavitt, SM Park, J TI Microstructure and phase identification in type 304 stainless steel-zirconium alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID ZR; IRRADIATION; ZIRCALOY-2; SYSTEM AB Stainless steel-zirconium alloys have been developed at Argonne National Laboratory to contain radioactive metal isotopes isolated from spent nuclear fuel. This article discusses the various phases that are formed in as-cast alloys of type 304 stainless steel and zirconium that contain up to 92 wt pct Zr. Microstructural characterization was performed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), and crystal structure information was obtained by X-ray diffraction. Type 304SS-Zr alloys with 5 and 10 wt pct Zr have a three-phase microstructure-austenite, ferrite, and the Laves intermetallic, Zr(Fe,Cr,Ni)(2+x), whereas alloys with 15, 20, and 30 wt pct Zr contain only two phases-ferrite and Zr(Fe,Cr,Ni)(2+x). Alloys with 45 to 67 wt pct Zr contain a mixture of Zr(Fe,Cr,Ni)(2+x) and Zr-2(Ni,Fe), whereas alloys with 83 and 92 wt pct Zr contain three phases-alpha-Zr, Zr-2(Ni,Fe), and Zr(Fe,Cr,Ni)(2+x). Fe3Zr-type and Zr3Fe-type phases were not observed in the type 304SS-Zr alloys. The changes in alloy microstructure with zirconium content have been correlated to the Fe-Zr binary phase diagram. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. RP Abraham, DP (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 29 TC 27 Z9 27 U1 0 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD AUG PY 1996 VL 27 IS 8 BP 2151 EP 2159 DI 10.1007/BF02651870 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VC633 UT WOS:A1996VC63300012 ER PT J AU Park, JS Verhoeven, JD AF Park, JS Verhoeven, JD TI Directional solidification of white cast iron SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID C-SI ALLOYS; FE-C; MORPHOLOGICAL TRANSITIONS; GROWTH; TE AB Several studies of the ledeburite eutectic (Fe-Fe3C), in pure Fe-C alloys have shown that it has a lamellar morphology under plane front growth conditions. The structure of ledeburite in white cast irons, Fe-C-Si, consists of a rod morphology. It is generally not possible to produce plane front growth of Fe-C-Si eutectic alloys in the Fe-Fe3C form, because at the slow growth rates required for plane front growth, the Fe3C phase is replaced by graphite. By using small additions of Te, the growth of graphite was suppressed, and the plane front growth of the ledeburite eutectic in Fe-C-Si alloys was carried out with Si levels up to 1 wt pet. It was found that the growth morphology became a faceted rod morphology at 1 wt pet Si, but in contrast to the usual rod morphology of white cast irons, the rod phase was Fe3C rather than iron. It was shown that the usual rod morphology only forms at the sides of the two-phase cellular or dendritic growth fronts in Fe-C-Si alloys. Possible reasons for the inability of plane front directional solidification to produce the usual rod morphology in Fe-C-Si alloys are discussed. Also, data are presented on the spacing of the lamellar eutectic in pure Fe-C ledeburite, which indicates that this system does not follow the usual lambda(2)V = constant relation of regular eutectics. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT MAT SCI & ENGN, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. RP Park, JS (reprint author), HONGIK UNIV, DEPT MET ENGN, CHOCHIWON 339800, SOUTH KOREA. NR 25 TC 19 Z9 20 U1 3 U2 6 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD AUG PY 1996 VL 27 IS 8 BP 2328 EP 2337 DI 10.1007/BF02651887 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VC633 UT WOS:A1996VC63300029 ER PT J AU Smith, WS Kao, CYJ AF Smith, WS Kao, CYJ TI Numerical simulations of the marine stratocumulus-capped boundary layer and its diurnal variation SO MONTHLY WEATHER REVIEW LA English DT Article ID RADIATIVE PROPERTIES; MIXED LAYER; SOLAR-RADIATION; CLOUDS; MODEL; FIRE; ATMOSPHERE; GATE AB A high-resolution one-dimensional version of a second-order turbulence radiative-convective model, developed at Los Alamos National Laboratory, is used to simulate the diurnal cycle of the marine stratocumulus cloud-capped boundary layer. The fidelity of the model to the underlying physics is assessed by comparing the model simulation to data taken at San Nicolas Island during the intensive field observation (IFO) of the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE), conducted during June and July 1987. The model is able to reproduce the observed diurnal cycle of the liquid water content, cloud-base height, radiative heating or cooling rates, and the mean and turbulence variables fairly well. The mechanisms that cause the diurnal variation and the decoupling of the boundary layer are examined. The possible role of an imposed diurnal cycle for the subsidence in inducing the cloud-top diurnal cycle observed during the FIRE IFO is also addressed. Three regimes of subsidence influence are identified for the stratocumulus-capped boundary layer. Regimes I and III are characterized by vertical propagation of the inversion height and erratic fluctuation of turbulence in the region of the inversion. Regime II is characterized by a continuum of quasi-equilibrium states that can exist for a range of subsidence values. In this regime, the boundary layer height is fairly insensitive to changes in the subsidence. The boundary layer behavior implied for these regimes is used to explore the effect of a diurnally Varying subsidence rate on the diurnal cycle for the cloud-top height. C1 NEW MEXICO STATE UNIV,DEPT PHYS,LAS CRUCES,NM 88003. RP Smith, WS (reprint author), LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,EES-5,MAIL STOP D-401,LOS ALAMOS,NM 87545, USA. NR 36 TC 11 Z9 12 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD AUG PY 1996 VL 124 IS 8 BP 1803 EP 1816 DI 10.1175/1520-0493(1996)124<1803:NSOTMS>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VB338 UT WOS:A1996VB33800011 ER PT J AU Phillips, JM AF Phillips, JM TI Workshop identifies opportunities for materials researchers SO MRS BULLETIN LA English DT Editorial Material RP Phillips, JM (reprint author), SANDIA NATL LABS, SURFACE & SENSOR CONTROLLED PROC DEPT, LIVERMORE, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD AUG PY 1996 VL 21 IS 8 BP 13 EP 13 PG 1 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA VD210 UT WOS:A1996VD21000015 ER PT J AU Collins, G Rej, DJ AF Collins, G Rej, DJ TI Plasma processing of advanced materials SO MRS BULLETIN LA English DT Article C1 CTR RECH PHYS PLASMAS,LAUSANNE,SWITZERLAND. LOS ALAMOS NATL LAB,TECH STAFF,LOS ALAMOS,NM 87545. RP Collins, G (reprint author), AUSTRALIAN NUCL SCI & TECHNOL ORG,DIV MAT,PLASMA SURFACE ENGN GRP,MENAI,NSW 2234,AUSTRALIA. RI Collins, George/C-7984-2009 NR 0 TC 9 Z9 9 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0883-7694 J9 MRS BULL JI MRS Bull. PD AUG PY 1996 VL 21 IS 8 BP 26 EP 31 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA VD210 UT WOS:A1996VD21000018 ER PT J AU Mahamuni, S Bendre, BS Leppert, VJ Smith, CA Cooke, D Risbud, SH Lee, HWH AF Mahamuni, S Bendre, BS Leppert, VJ Smith, CA Cooke, D Risbud, SH Lee, HWH TI ZnO nanoparticles embedded in polymeric matrices SO NANOSTRUCTURED MATERIALS LA English DT Article ID SIZE QUANTIZATION; PHOTOCHEMISTRY; PARTICLES; COLLOIDS; CLUSTERS; CDS AB Highly stable, wurtzite quantum sized ZnO colloids encapsulated in polymers have been synthesized. The particles can be obtained in a powder form and are partially redissolvable in organic media. A shift in the optical absorption spectrum confirms quantum size effects. Stationary fluorescence measurements exhibit excitonic as well as trapped fluorescence. The intensity of trapped fluorescence changes with capping. The time resolved fluorescence measurements indicate considerably short decay times. C1 UNIV CALIF DAVIS,DEPT CHEM ENGN & MAT SCI,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Mahamuni, S (reprint author), UNIV PUNE,DEPT PHYS,PUNE 411007,MAHARASHTRA,INDIA. NR 14 TC 38 Z9 40 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD AUG PY 1996 VL 7 IS 6 BP 659 EP 666 DI 10.1016/0965-9773(96)00043-8 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA VD622 UT WOS:A1996VD62200008 ER PT J AU Boyer, K Solem, JC Longworth, JW Borisov, AB Rhodes, CK AF Boyer, K Solem, JC Longworth, JW Borisov, AB Rhodes, CK TI Biomedical three-dimensional holographic microimaging at visible, ultraviolet and X-ray wavelengths SO NATURE MEDICINE LA English DT Article C1 UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607. MCR TECHNOL CORP,CHICAGO,IL 60610. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. IIT,DEPT PHYS,CHICAGO,IL 60616. UNIV TSUKUBA,TSUKUBA,IBARAKI 305,JAPAN. NR 11 TC 24 Z9 24 U1 0 U2 2 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1078-8956 J9 NAT MED JI Nat. Med. PD AUG PY 1996 VL 2 IS 8 BP 939 EP 941 DI 10.1038/nm0896-939 PG 3 WC Biochemistry & Molecular Biology; Cell Biology; Medicine, Research & Experimental SC Biochemistry & Molecular Biology; Cell Biology; Research & Experimental Medicine GA UZ804 UT WOS:A1996UZ80400044 PM 8705867 ER PT J AU Gourley, PL AF Gourley, PL TI Semiconductor microlasers: A new approach to cell-structure analysis SO NATURE MEDICINE LA English DT Article RP Gourley, PL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 19 TC 22 Z9 22 U1 0 U2 1 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1078-8956 J9 NAT MED JI Nat. Med. PD AUG PY 1996 VL 2 IS 8 BP 942 EP 944 DI 10.1038/nm0896-942 PG 3 WC Biochemistry & Molecular Biology; Cell Biology; Medicine, Research & Experimental SC Biochemistry & Molecular Biology; Cell Biology; Research & Experimental Medicine GA UZ804 UT WOS:A1996UZ80400045 PM 8705868 ER PT J AU Dong, LM Parkin, S Trakhanov, SD Rupp, B Simmons, T Arnold, KS Newhouse, YM Innerarity, TL Weisgraber, KH AF Dong, LM Parkin, S Trakhanov, SD Rupp, B Simmons, T Arnold, KS Newhouse, YM Innerarity, TL Weisgraber, KH TI Novel mechanism for defective receptor binding of apolipoprotein E2 in type III hyperlipoproteinemia SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID HUMAN-E APOPROTEIN; DOMAIN; SITE; POLYMERASE; PROTEIN AB The defective binding of apolipoprotein (ape) E2 to lipoprotein receptors, an underlying cause of type III hyperlipoproteinemia, results from replacement of Arg 158 with Cys, disrupting the naturally occurring salt bridge between Asp 154 and Arg 158. A new bond between Asp 154 and Arg 150 is formed, shifting Arg 150 out of the receptor binding region. Elimination of the 154-150 salt bridge by site-directed mutagenesis of Asp 154 to Ala restored the receptor binding activity to near normal levels. The X-ray crystal structure of apoE2 Ala 154 demonstrated that Arg 150 was relocated within the receptor binding region. Our results demonstrate that defective binding of apoE2 occurs by a novel mechanism of the replacement of one salt bridge with another. C1 UNIV CALIF SAN FRANCISCO,GLADSTONE INST CARDIOVASC DIS,SAN FRANCISCO,CA 94141. UNIV CALIF SAN FRANCISCO,INST CARDIOVASC RES,SAN FRANCISCO,CA 94141. UNIV CALIF SAN FRANCISCO,DEPT PATHOL,SAN FRANCISCO,CA 94141. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. RI Parkin, Sean/E-7044-2011 NR 30 TC 87 Z9 88 U1 2 U2 6 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD AUG PY 1996 VL 3 IS 8 BP 718 EP 722 DI 10.1038/nsb0896-718 PG 5 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA VA150 UT WOS:A1996VA15000017 PM 8756331 ER PT J AU Diercks, DR Muscara, J Shack, WJ AF Diercks, DR Muscara, J Shack, WJ TI Steam generator tube integrity program SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB The degradation of steam generator tubes in pressurized water nuclear reactors continues to be a serious problem, and the US Nuclear Regulatory Commission (NRC) is developing a performance-based rule and regulatory guide for steam generator tube integrity. To support the evaluation of industry-proposed implementation of these performance-based criteria, the NRC is sponsoring a new research program at Argonne National Laboratory on steam generator tubing degradation. The objective of the new program is to provide the necessary experimental data and predictive correlations and models that will permit the NRC to independently evaluate the integrity of steam generator tubes. The technical work in the program is divided into four tasks, (1) assessment of inspection reliability, (2) research on in-service inspection technology, (3) research on degradation modes and integrity, and (4) development of methodology and technical assessments for current and emerging regulatory issues. The objectives of and planned research activities under each of these four tasks are described here. C1 US NUCL REGULATORY COMMISS,OFF NUCL REGULATORY RES,WASHINGTON,DC 20555. RP Diercks, DR (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 8 TC 8 Z9 8 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD AUG PY 1996 VL 165 IS 1-2 BP 143 EP 149 DI 10.1016/0029-5493(96)01234-4 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VN057 UT WOS:A1996VN05700010 ER PT J AU Pilch, MM Yan, H Theofanous, TG AF Pilch, MM Yan, H Theofanous, TG TI The probability of containment failure by direct containment heating in Zion SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article ID LOWER HEAD; RUPTURE AB This paper is the first step in the resolution of the direct containment heating (DCH) issue for the Zion nuclear power plant using the risk oriented accident analysis methodology (ROAAM). This paper includes the definition of a probabilistic framework that decomposes the DCH problem into three probability density functions that reflect the most uncertain initial conditions (UO2 mass, zirconium oxidation fraction, and steel mass). Uncertainties in the initial conditions are significant, but our quantification approach is based on establishing reasonable bounds that are not unnecessarily conservative. To this end, we also make use of the ROAAM ideas of enveloping scenarios and 'splintering'. Two causal relations (CRs) are used in this framework: CR1 is a model that calculates the peak pressure in the containment as a function of the initial conditions, and CR2 is a model that returns the frequency of containment failure as a function of pressure within the containment. Uncertainty in CR1 is accounted for by the use of two independently developed phenomenological models, the convection-limited containment heating model and the two-cell equilibrium model, and by probabilistically distributing the key parameter in both, which is the ratio of the melt entrainment time to the system blowdown time constant. The two phenomenological models have been compared with an extensive database including recent integral simulations at two different physical scales (1:10-scale in the Surtsey facility at Sandia National Laboratories and 1:40-scale in the COREXIT facility at Argonne National Laboratory). The loads predicted by these models were significantly lower than those from previous parametric calculations. The containment load distributions do not intersect the containment strength (fragility) curve in any significant way, resulting in containment failure probabilities less than 10(-3) for all scenarios considered. Sensitivity analyses did not show any areas of large sensitivity. The feasibility of extrapolating containment loads distributions to most other pressurized water reactors is explored. C1 UNIV CALIF SANTA BARBARA,CTR RISK STUDIES,SANTA BARBARA,CA 93106. UNIV CALIF SANTA BARBARA,DEPT CHEM & NUCL ENGN,SANTA BARBARA,CA 93106. RP Pilch, MM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 34 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD AUG PY 1996 VL 164 IS 1-3 BP 1 EP 36 DI 10.1016/0029-5493(96)01227-7 PG 36 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VH292 UT WOS:A1996VH29200002 ER PT J AU Pilch, MM Allen, MD AF Pilch, MM Allen, MD TI Closure of the direct containment heating issue for Zion SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB This paper, which was originally published in more detail (M.M. Pilch, M.D. Alien, D.L. Knudsen, D.W. Stamps and E.L. Tadios, Rep. NUREG/CR-6075, Supplement 1, 1994b (Sandia National Laboratories, Albuquerque, NM)), provides closure of the direct containment heating (DCH) issue for the Zion plant. It incorporates the comments and suggestions of the peer reviewers of NUREG/CR-6075 (M.M. Pilch, H. Yan, and T.G. Theofanous, Rep. NUREG/ CR-6075, SAND93-1535, 1994a (Sandia National Laboratories, Albuquerque, NM)) and specifically includes assessments of four new splinter scenarios defined in working group meetings and modeling enhancements recommended by the working groups. In the four new scenarios, consistency of the initial conditions has been implemented by using insights from systems-level codes. SCDAP/RELAP5 was used to analyze three short-term station blackout cases with different leak rates. In all three cases, the hot leg or surge line failed well before the lower head and thus the primary system depressurized to a point where DCH was no longer considered a threat. However, these calculations were continued to lower head failure in order to gain insights that were useful in establishing the initial and boundary conditions. The most useful insights are that the reactor coolant system pressure is low at vessel breach, metallic blockages in the core region do not melt and relocate into the lower plenum, and melting of upper plenum steel is correlated with hot leg failure. The SCDAP/RELAP5 output was used as input to CONTAIN to assess the containment conditions at vessel breach. The containment-side conditions predicted by CONTAIN are similar to those originally specified in NUREG/CR-6075. The methodology originally developed in NUREG/CR-6075 (M.M. Pilch, H. Yan, and T.G. Theofanous, Rep. NUREG/CR-6075, SAND93-1535, 1994a (Sandia National Laboratories, Albuquerque, NM)) was used to analyze the new splinter scenarios. Some modeling enhancements in response to working group discussions were implemented for these analyses. The entrainment of hydrogen pre-existing in the atmosphere into a burning jet was examined more carefully. In addition, the impact of DCH-induced deflagrations on DCH loads was quantified. A new computational tool-the two-cell equilibrium-Latin hypercube sampling (TCE-LHS) code-was developed for this effort to perform Monte Carlo sampling of the scenario distributions. The TCE-LHS code was benchmarked against the original Scenario I calculations in NUREG/CR-6075 performed using the ALPHA code, which is based on the method of discrete probability distributions. The results were in excellent agreement. The analyses of the new scenarios showed no intersection of the load distributions and the containment fragility curves, and thus the containment failure probability was negligible for each scenario. These supplemental analyses complete closure of the DCH issue for Zion. RP Pilch, MM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 23 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD AUG PY 1996 VL 164 IS 1-3 BP 37 EP 60 DI 10.1016/0029-5493(96)01229-0 PG 24 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VH292 UT WOS:A1996VH29200003 ER PT J AU Pilch, MM AF Pilch, MM TI A two-cell equilibrium model for predicting direct containment heating SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB This paper discusses two adiabatic equilibrium models. Assessment and validation of the separate effects (kinetic) models and the parameters (i.e. particle size) that control them are not required. The first, a single-cell equilibrium model, places a true upper bound on direct containment heating (DCH) loads. This upper bound, when compared with the entire DCH database, often far exceeds experiment observations by a margin too large to be useful in reactor analyses. The single-cell model is used as a conceptual seed for a two-cell model. A two-cell equilibrium (TCE) model is developed that captures the dominant mitigating features of containment compartmentalization and the noncoherence of the entrainment and blowdown processes. The existing DCH database has been used to extensively validate the TCE model. DCH loads are shown to be insensitive to physical scale and details of the subcompartment geometry. A simple model is developed to predict the coherence of debris dispersal and reactor coolant system blowdown. The coherence ratio is independent of physical scale and only weakly dependent on cavity design. RP Pilch, MM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 70 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD AUG PY 1996 VL 164 IS 1-3 BP 61 EP 94 DI 10.1016/0029-5493(96)01230-7 PG 34 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VH292 UT WOS:A1996VH29200004 ER PT J AU Pilch, MM AF Pilch, MM TI Hydrogen combustion during direct containment heating events SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article ID FLAMMABILITY LIMITS; MIXTURES; TEMPERATURES; AIR AB Direct containment heating (DCH) has the potential to cause short-term overpressure failure of the containment in a nuclear power plant that has experienced a core melt accident. This paper addresses the possible modes of hydrogen combustion in the dome region of a pressurized water reactor containment building during a DCH event. The combustion modes considered are: combustion of hot hydrogen jets, deflagrations, volumetric combustion, and mixing limited combustion. The limits for each combustion mode are defined and interpreted in the context of both experiment and reactor applications. With the exception of jet combustion, heat transfer to structures can significantly limit the contribution of hydrogen combustion to peak containment pressures on the DCH time scale. Implementation of these hydrogen combustion models into the two-cell equilibrium model is discussed. RP Pilch, MM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 32 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD AUG PY 1996 VL 164 IS 1-3 BP 117 EP 136 DI 10.1016/0029-5493(96)01228-9 PG 20 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VH292 UT WOS:A1996VH29200006 ER PT J AU Pilch, MM AF Pilch, MM TI Continued enlargement of the initial failure site in the reactor pressure vessel SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB Molten core material is considerably hotter than the melting point of the RPV steel; consequently, cerium discharge could be accompanied by rapid ablation of the hole initially formed in the RPV by tube ejection or creep rupture. In rupture scenarios, the formation of a hole creates a localized stress concentration that might cause the initial failure to propagate to a much larger size. These processes not only accelerate cerium discharge, but the resulting hole size has a direct influence on RCS blowdown, debris fragmentation, dispersal of debris from the cavity, and subsequent containment phenomena. The final hole size plays a central role in the quantification of the coherence ratio, which defines the coherency of melt dispersal and RCS blowdown in the two-cell equilibrium (TCE) model. This paper develops a model for the final hole size after ablation. The applicability of the model to both experiment and reactor analyses is addressed. The ablation model is validated against existing experiment data, but extrapolation outside the database is required for NPP applications. Sensitivity studies are performed over the extremes of the controlling parameters. Simple analysis suggests that RCS depressurization effectively eliminates any possibility of continued enlargement of a rupture once it is formed. RP Pilch, MM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD AUG PY 1996 VL 164 IS 1-3 BP 137 EP 146 DI 10.1016/0029-5493(96)01231-9 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VH292 UT WOS:A1996VH29200007 ER PT J AU Blanchat, TK Allen, MD AF Blanchat, TK Allen, MD TI Experiments to investigate DCH phenomena with large-scale models of the Zion and Surry nuclear power plants SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB The Surtsey Test Facility and the Containment Technology Test Facility (CTTF) at Sandia National Laboratories (SNL) have been used to perform scaled experiments for the Nuclear Regulatory Commission (NRC) that simulate high-pressure melt ejection (HPME) accidents in a nuclear power plant (NPP). These experiments are designed to investigate the effects of direct containment heating (DCH) phenomena on the containment load. High-temperature, chemically reactive alumino (thermitic) melt is ejected by high-pressure steam into a scale model of either the Zion or Surry NPP. Integral effects tests under prototypic conditions have been performed to investigate the effects of dispersal of molten core materials on DCH loads, and to study the effects of Westinghouse plant configurations on DCH loads. In Westinghouse plants, there is (1) an intermediate compartment that is large compared with the reactor cavity but small compared with the main containment volume, and (2) no significant line-of-sight pathway for debris transport from the cavity to the main containment volume. Containment compartmentalization is the dominant mitigating feature for Zion, Surry, and most other pressurized water reactors. Experimental results will be used to further assess the applicability of existing DCH models to Westinghouse plants on DCH loads. RP Blanchat, TK (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 14 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD AUG PY 1996 VL 164 IS 1-3 BP 147 EP 174 DI 10.1016/0029-5493(96)01218-6 PG 28 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VH292 UT WOS:A1996VH29200008 ER PT J AU Binder, JL Spencer, BW AF Binder, JL Spencer, BW TI Investigations into the physical phenomena and mechanisms that effect direct containment heating loads SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB Integral direct containment heating (DCH) experiment results are presented. The results are analyzed and discussed for the insights they have given into understanding the important physical phenomena and mechanisms that effect DCH loads to the containment. Particular attention is paid to (1) debris dispersal from the cavity and containment structure trapping, (2) hydrogen production and combustion, (3) the importance of difference in cerium simulants used in integral DCH experiments and (4) cerium debris quenching by flooded cavities. It is found that much has been learned about DCH phenomena that can be used for modeling and assessing potential containment loads. RP Binder, JL (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 11 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD AUG PY 1996 VL 164 IS 1-3 BP 175 EP 199 DI 10.1016/0029-5493(96)01219-8 PG 25 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VH292 UT WOS:A1996VH29200009 ER PT J AU Washington, KE Stuart, DS AF Washington, KE Stuart, DS TI Comparison of CONTAIN and TCE calculations for direct containment heating of Surry SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB This paper presents the results of several CONTAIN code calculations used to model direct containment heating (DCH) loads for the Surry plant. The results of these calculations are compared with the results obtained using the two-cell equilibrium (TCE) model for the same set of initial and boundary conditions. This comparison is important because both models have been favorably validated against the available DCH database, yet there are potentially important modeling differences. The comparisons are to quantitatively assess the impact of these differences. A major conclusion of this study is that, for the accident conditions studied and for a broad range of sensitivity cases, the peak pressures predicted by both TCE and CONTAIN are well below the failure pressure for the Surry containment. RP Washington, KE (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD AUG PY 1996 VL 164 IS 1-3 BP 201 EP 210 DI 10.1016/0029-5493(96)01220-4 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VH292 UT WOS:A1996VH29200010 ER PT J AU Zweben, SJ Budny, RV Cheng, CZ Frederickson, ED Fu, GY Mikkelsen, DR Schmidt, GL Scott, SD Spong, DA Bush, CE Chang, Z Darrow, DS Fonck, RJ Grisham, LR Mazzucato, E Nazikian, R Owens, DK Park, HK Paul, SF Schivell, JF Strachan, JD Synakowski, EJ Taylor, G Young, KM AF Zweben, SJ Budny, RV Cheng, CZ Frederickson, ED Fu, GY Mikkelsen, DR Schmidt, GL Scott, SD Spong, DA Bush, CE Chang, Z Darrow, DS Fonck, RJ Grisham, LR Mazzucato, E Nazikian, R Owens, DK Park, HK Paul, SF Schivell, JF Strachan, JD Synakowski, EJ Taylor, G Young, KM TI Search for alpha driven TAEs at lowered ion temperature in TFTR DT discharges SO NUCLEAR FUSION LA English DT Article ID INDUCED ALFVEN EIGENMODES; FUSION TEST REACTOR; DIII-D; TOROIDICITY; MODES; STABILITY; TOKAMAK; PLASMAS; DEUTERIUM; EXCITATION AB An experiment was performed in TFTR DT plasmas in an attempt to destabilize the alpha particle driven toroidicity-induced Alfven eigenmodes (TAEs) by reducing their thermal ion Landau damping. The thermal ion Landau damping was reduced by transiently lowering the ion temperature using either helium (He) gas puffs or deuterium (D) or lithium (Li) pellet injection during neutral beam injection (NBI) into DT supershots. The ion temperature was successfully lowered from T-i(0) approximate to 20 keV to T-i(0) approximate to 10 keV in about 0.2 s; however, no alpha driven TAEs were observed. Theoretical analyses of the TAE instability of these DT discharges indicate that the alpha pressure required for TAE stability still remained greater than that actually obtained in this experiment, mainly because of the effects of beam ion Landau damping. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. UNIV WISCONSIN,MADISON,WI. RP Zweben, SJ (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Spong, Donald/C-6887-2012; Cheng, Chio/K-1005-2014 OI Spong, Donald/0000-0003-2370-1873; NR 45 TC 10 Z9 10 U1 1 U2 6 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 AUG PY 1996 VL 36 IS 8 BP 987 EP 1008 DI 10.1088/0029-5515/36/8/I04 PG 22 WC Physics, Fluids & Plasmas SC Physics GA XY893 UT WOS:A1996XY89300005 ER PT J AU Kruger, SE Budny, RV Callen, JD Chang, Z Skinner, CH Strachan, JD AF Kruger, SE Budny, RV Callen, JD Chang, Z Skinner, CH Strachan, JD TI Investigations of tritium recycling in TFTR using the DT neutron rate SO NUCLEAR FUSION LA English DT Letter ID SUPERSHOT AB During deuterium-only neutral beam injected discharges, tritium from earlier deuterium-tritium (DT) discharges is released from the vessel limiters and walls to cause a DT neutron count rate comparable to the DD neutron count rate. A measure of the tritium density in the plasma based on neutron rate measurements is defined and used to determine which parameters influence tritium influx to the plasma core. The tritium density is observed to decrease in a sequence of deuterium-only supershots and to depend on the amount of tritium injected in prior DT shots and on the amount of tritium present in the limiter. A weak correlation is also observed with the plasma current, but not with beam power, hydrogen influx, carbon influx, visible bremsstrahlung, lithium pellet injection, blooms or disruptions. C1 UNIV WISCONSIN,MADISON,WI. RP Kruger, SE (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 7 TC 2 Z9 2 U1 1 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 AUG PY 1996 VL 36 IS 8 BP 1053 EP 1056 DI 10.1088/0029-5515/36/8/I09 PG 4 WC Physics, Fluids & Plasmas SC Physics GA XY893 UT WOS:A1996XY89300010 ER PT J AU Stroth, U Murakami, M Dory, RA Yamada, H Okamura, S Sano, F Obiki, T AF Stroth, U Murakami, M Dory, RA Yamada, H Okamura, S Sano, F Obiki, T TI Energy confinement scaling from the international stellarator database SO NUCLEAR FUSION LA English DT Article ID ADVANCED TOROIDAL FACILITY; NEUTRAL BEAM; HELIOTRON-E; H-MODE; VII-A; PLASMAS; TORSATRON; TRANSPORT; DEVICES; PHYSICS AB An international stellarator database on global energy confinement is presented. It comprises a total of 859 discharges from the ATF, CHS and Heliotron-E heliotron/torsatrons and the W7-A and W7-AS shearless stellarators. Some design aspects and operation techniques of the different devices are discussed. The data in the database represent electron cyclotron heated (ECH) and neutral beam injection (NBI) heated discharges in the L mode confinement regime. Results from enhanced confinement regimes such as H mode will be reported elsewhere. Regression expressions for the energy confinement time are given for the individual devices, for the subsets of heliotron/torsatrons and shearless stellarators and for the combined dataset. The combined scaling ISS-95 is found to describe satisfactorily a large tokamak L mode dataset. The aspects of comparing stellarator and tokamak data are discussed on the basis of various scaling expressions. In order to make this database available to interested colleagues, the structure of the database, which is described in detail, is organized in a similar way as the ITER confinement databases. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN USA. NATL INST FUS SCI, NAGOYA, AICHI, JAPAN. KYOTO UNIV, PLASMA PHYS LAB, UJI 611, JAPAN. RP Stroth, U (reprint author), EURATOM IPP ASSOC, MAX PLANCK INST PLASMAPHYS, GARCHING, GERMANY. NR 43 TC 211 Z9 213 U1 1 U2 10 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0029-5515 EI 1741-4326 J9 NUCL FUSION JI Nucl. Fusion PD AUG PY 1996 VL 36 IS 8 BP 1063 EP 1077 DI 10.1088/0029-5515/36/8/I11 PG 15 WC Physics, Fluids & Plasmas SC Physics GA XY893 UT WOS:A1996XY89300012 ER PT J AU Hogan, JT Hillis, DL AF Hogan, JT Hillis, DL TI Helium transport and exhaust in tokamaks - Report on the 3rd International Workshop Held at Charleston, South Carolina, United States of America, 25-28 September 1995 SO NUCLEAR FUSION LA English DT Article ID OF-AMERICA RP Hogan, JT (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 3 TC 2 Z9 2 U1 0 U2 0 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 AUG PY 1996 VL 36 IS 8 BP 1079 EP 1090 DI 10.1088/0029-5515/36/8/412 PG 12 WC Physics, Fluids & Plasmas SC Physics GA XY893 UT WOS:A1996XY89300013 ER PT J AU Wunstorf, R Bugg, WM Walter, J Garber, FW Larson, D AF Wunstorf, R Bugg, WM Walter, J Garber, FW Larson, D TI Investigations of donor and acceptor removal and long term annealing in silicon with different boron/phosphorus ratios SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY ID IMPURITY CONCENTRATION; DETECTORS AB Studies of radiation damage of silicon detectors have shown that in most elementary particle physics applications, the major problem caused by non-ionizing interactions in silicon will be the change in the concentration of the electrically active impurity states. For many silicon applications in high radiation environments, the increase in the relative acceptor concentration during long term room temperature annealing is the limiting factor. The first step in developing radiation hardened silicon is to identify the defects which are responsible for this effect. In earlier work, we developed a model which describes the experimentally observed fast neutron induced changes in the net electrically active impurity concentration and provides a method to determine the phosphorus and boron concentration of the starting material. Our previous work has been extended with experiments using silicon with different original boron/phosphorus ratios, larger neutron fluences and to long term room temperature annealing. The donor removal rate of phosphorus was measured and the acceptor removal rate of boron evaluated. Extending our model, we propose that slow restoration of the damage induced boron interstitial back to its original substitutional state is responsible for the acceptor increase observed during long term annealing. This model, which involves only the behavior of the known shallow donors and accepters present in the starting material, fits our data and the data of other experimenters without the need to invoke unidentified deep levels. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. INTRASPEC INC,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 14 TC 21 Z9 21 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 1 PY 1996 VL 377 IS 2-3 BP 228 EP 233 DI 10.1016/0168-9002(96)00217-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600010 ER PT J AU Li, Z Li, CJ Eremin, V Verbitskaya, E AF Li, Z Li, CJ Eremin, V Verbitskaya, E TI Investigation on the N-eff reverse annealing effect using TSC/I-DLTS: Relationship between neutron induced microscopic defects and silicon detector electrical degradations SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY ID RADIATION-DAMAGE; RESISTIVITY AB Neutron induced defect levels in high resistivity silicon detectors have been studied using a current-based macroscopic defect analysis system: thermally stimulated current (TSC) and current deep level transient spectroscopy (I-DLTS). These studies have been correlated to the traditional C-V, I-V, and transient current and charge techniques (TCT/TChT) after neutron radiation and subsequent thermal anneals. It has been found that the increases of the space charge density, N-eff, in irradiated detectors after thermal anneals (N-eff reverse anneal) correspond to the increases of deep levels in the silicon bandgap. In particular, increases of the double vacancy center (V-V and V-V-- -) and/or C-i-O-i level have good correlations with the N-eff reverse anneal. It has also been observed that the leakage current of highly irradiated (Phi(n) > 10(13) n/cm(2)) detectors increases after thermal anneals, which is different from the leakage current annealing behavior of slightly irradiated (Phi(n) < 10(13) n/cm(2)) detectors. It is apparent that V-V center and/or C-i-O-i level play important roles in both N-eff and leakage current degradations for highly irradiated high resistivity silicon detectors. C1 CHINESE ACAD SCI,INST SEMICOND,BEIJING 100083,PEOPLES R CHINA. RP Li, Z (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Verbitskaya, Elena/D-1521-2014 NR 18 TC 19 Z9 19 U1 1 U2 5 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 1 PY 1996 VL 377 IS 2-3 BP 265 EP 275 DI 10.1016/0168-9002(95)01410-1 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600014 ER PT J AU Walton, JT Krofcheck, D ODonnell, R Odyniec, G Partlan, MD Wang, NW AF Walton, JT Krofcheck, D ODonnell, R Odyniec, G Partlan, MD Wang, NW TI P-type silicon drift detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY AB Preliminary results on 16 cm(2), position-sensitive silicon drift detectors, fabricted for the first time on p-type silicon substrates, are presented. The detectors were designed, fabricated, and tested recently at LBL and show interesting properties which make them attractive for use in future physics experiments. A pulse count rate of approximately 8 x 10(6) s(-1) was demonstrated by the p-type silicon drift detectors. This count rate estimate was derived by measuring simultaneous tracks produced by a laser which was collimated using a photolithographic mask. RP Walton, JT (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 7 TC 0 Z9 0 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 1 PY 1996 VL 377 IS 2-3 BP 357 EP 361 DI 10.1016/0168-9002(96)00215-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600026 ER PT J AU Faschingbauer, U Agakichiev, G Baur, R Ceretto, F Dress, A Fraenkel, Z Fuchs, C Gatti, E Glassel, P Hess, F Hemberger, M delosHeros, CP Holl, P Irmscher, D Jacob, C Kemmer, J Minaev, Y Panebrattsev, Y Pfeiffer, A Ravinovich, I Razin, S Rehak, P Sampietro, M SChukraft, J Shimanskiy, S Socol, E Specht, HJ TelZur, G Tserruya, I Ullrich, T Voigt, C Wurm, JP Yurevich, V AF Faschingbauer, U Agakichiev, G Baur, R Ceretto, F Dress, A Fraenkel, Z Fuchs, C Gatti, E Glassel, P Hess, F Hemberger, M delosHeros, CP Holl, P Irmscher, D Jacob, C Kemmer, J Minaev, Y Panebrattsev, Y Pfeiffer, A Ravinovich, I Razin, S Rehak, P Sampietro, M SChukraft, J Shimanskiy, S Socol, E Specht, HJ TelZur, G Tserruya, I Ullrich, T Voigt, C Wurm, JP Yurevich, V TI Doublet of 3 in cylindrical silicon drift detectors in the CERES experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY AB We report on the performance of a doublet of 3 in. cylindrical silicon drift detectors installed as an upgrade of the CERES/NA45 electron pair spectrometer for the Pb-beam at the CERN SPS. The silicon detectors provide external particle tracking and background rejection of conversions and close Dalitz pairs. Results on vertex reconstruction and rejection from a Pb test-run in 1994 are presented. C1 JINR,RU-141980 DUBNA,RUSSIA. UNIV HEIDELBERG,INST PHYS,D-69120 HEIDELBERG,GERMANY. WEIZMANN INST SCI,IL-76100 REHOVOT,ISRAEL. POLITECN MILAN,I-20133 MILAN,ITALY. KETEK GMBH,D-85764 OBERSCHLEISSHEIM,GERMANY. BROOKHAVEN NATL LAB,UPTON,NY 11973. CERN,CH-1211 GENEVA 23,SWITZERLAND. RP Faschingbauer, U (reprint author), MAX PLANCK INST KERNPHYS,D-69117 HEIDELBERG,GERMANY. RI Sampietro, Marco/A-3732-2016; OI Sampietro, Marco/0000-0003-4825-9612; Perez de los Heros, Carlos/0000-0002-2084-5866 NR 9 TC 11 Z9 11 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 1 PY 1996 VL 377 IS 2-3 BP 362 EP 366 DI 10.1016/0168-9002(95)01403-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600027 ER PT J AU Holl, P Rehak, P Ceretto, F Faschingbauer, U Wurm, JP Castoldi, A Gatti, E AF Holl, P Rehak, P Ceretto, F Faschingbauer, U Wurm, JP Castoldi, A Gatti, E TI A 55 cm(2) cylindrical silicon drift detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY AB AZTEC, a large area cylindrical silicon drift detector was designed, produced and tested. AZTEC will be the building block of the NA45 and WA98 micro vertex detectors at CERN. Two AZTEC detectors are placed down stream from the target to measure trajectories of charged particles produced in the forward direction. The active area of AZTEC is practically the full usable surface of a 100 mm diameter wafer. The electrons drift radially from the center towards the outside. The sensing anodes are located at a radius of 42 mm. The center of the wafer is cut out and forms a passage for the non interacting beam, With a minimal radius for this hole the active region of the drift detector starts at an inner radius of 3.1 mm. Any larger radius can be selected if necessary. With this geometry and a typical operating voltage the maximum drift time is less than 4 mu s. Due to constrains in the mask layout the readout region and field electrodes are designed along the 360 sides of a symmetric polygon. All structures on one surface of the wafer are rotated by 0.5 degrees with respect to the other surface, In the middle plane of the detector, where the electrons are mostly transported, the effective geometry is close to a smoothed polygon with 720 sides, cancelling practically ail effects of the non-perfect cylindrical symmetry. The radial position of fast charged particles is measured by the electron drift time within the detector. The drift velocity can be monitored by 48 injection points at three different radii. The azimuthal angle is measured by the 360 readout anodes. Each anode is subdivided into five segments, which are interlaced with the neighbouring anodes. By this methode the azimuthal resolution is improved and corresponds to a 720 channel read out. C1 MAX PLANCK INST NUCL PHYS, D-69117 HEIDELBERG, GERMANY. UNIV MILAN, DEPT FIS, I-20133 MILAN, ITALY. POLITECN MILAN, I-20133 MILAN, ITALY. RP Holl, P (reprint author), BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. NR 3 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 1 PY 1996 VL 377 IS 2-3 BP 367 EP 374 DI 10.1016/0168-9002(96)00027-7 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600028 ER PT J AU Castoldi, A Rehak, P Holl, P AF Castoldi, A Rehak, P Holl, P TI A new silicon drift detector with reduced lateral diffusion SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY AB We present a method to reduce the effect of diffusion in the direction transverse to the drift in silicon drift detectors. This is achieved by creating regions of deep p-implant parallel to the drift direction that act as rigid guidelines during the drift of the charge cloud generated by a radiation interaction. The influence of the deep implanted accepters on the lateral confining held is discussed. A prototype has been designed, fabricated and tested. First experimental results are reported which demonstrate the achieved reduction of the lateral width of the electron cloud with respect to free broadening. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. MPI HALBLEITERLAB,D-81245 MUNICH,GERMANY. RP Castoldi, A (reprint author), UNIV MILAN,DIPARTIMENTO FIS,VIA CELORIA 16,I-20133 MILAN,ITALY. NR 9 TC 31 Z9 31 U1 0 U2 4 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 1 PY 1996 VL 377 IS 2-3 BP 375 EP 380 DI 10.1016/0168-9002(96)00019-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600029 ER PT J AU Bellwied, R Beuttenmueller, R Chen, W DiMassimo, D Dou, L Dyke, H French, A Hall, JR Hoffmann, GW Humanic, T Kotov, I Kraner, HW Liaw, CJ Lynn, D Paganis, S Ray, L Read, D Rykov, VL Pandey, SU Pruneau, C Schambach, J Sedlmeir, J Vilkelis, G Wilson, WK AF Bellwied, R Beuttenmueller, R Chen, W DiMassimo, D Dou, L Dyke, H French, A Hall, JR Hoffmann, GW Humanic, T Kotov, I Kraner, HW Liaw, CJ Lynn, D Paganis, S Ray, L Read, D Rykov, VL Pandey, SU Pruneau, C Schambach, J Sedlmeir, J Vilkelis, G Wilson, WK TI Development of large linear silicon drift detectors for the STAR experiment at RHIC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY ID PERFORMANCE; CHAMBER AB Large area linear Silicon Drift Detectors (SDD) are being developed for high energy and relativistic heavy ion collider experiments. SDDs have been proposed for the inner tracking detector in the STAR experiment at the BNL relativistic heavy ion collider to become operational in 1999. The Silicon Vertex Tracker (SVT) will consist of a three layer barrel structure composed of 216 individual detectors, each 6.3 x 6.3 cm(2). Prototypes, including one-way drift detectors (4.5 x 4.5 cm(2)) and bi-directional drift detectors (6 x 6 cm(2)) have been manufactured,and their properties have been studied. Design considerations, as well as test results, are presented in this article. Recent work has focused on minimizing the inactive guard structure area in order to optimize tracking efficiency. Particular attention is given to discussion of parameters that are sensitive to the reduced guard structure area, such as leakage current, maximum voltage and drift non-linearities. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV TEXAS,AUSTIN,TX 78712. WAYNE STATE UNIV,DETROIT,MI 48202. OI PAGANIS, STATHES/0000-0002-1950-8993 NR 10 TC 32 Z9 32 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 1 PY 1996 VL 377 IS 2-3 BP 387 EP 392 DI 10.1016/0168-9002(96)00024-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600031 ER PT J AU Fazzi, A Rehak, P AF Fazzi, A Rehak, P TI ''Gate-to-gate'' BJT obtained from the double-gate input JFET to reset charge preamplifiers SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY AB A novel charge restoration mechanism to reset charge sensitive preamplifiers is presented. The ''gate-to-gate'' Bipolar Junction Transistor transversal to the input JFET with independent top and bottom gates is exploited as a ''reset transistor'' embodied in the preamplifier input device. The p-n junction between the bottom gate and the channel is forward-biased by a proper feedback loop supplying the necessary restoration current to the input node capacitance through the top gate-channel reversed-biased junction. The continuous reset mode is here analysed with reference to the DC stability, the pulse response and the noise behaviour. Experimental results are reported. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Fazzi, A (reprint author), POLITECN MILAN,DIPARTIMENTO INGN NUCL,VIA PONZIO 34-3,I-20133 MILAN,ITALY. NR 6 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 1 PY 1996 VL 377 IS 2-3 BP 453 EP 458 DI 10.1016/0168-9002(96)00238-0 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600042 ER PT J AU Becker, R Grillo, A Jacobsen, R Johnson, R Kipnis, I Levi, M Luo, L Manfredi, PF Nyman, M Re, V Roe, N Shapiro, S AF Becker, R Grillo, A Jacobsen, R Johnson, R Kipnis, I Levi, M Luo, L Manfredi, PF Nyman, M Re, V Roe, N Shapiro, S TI Signal processing in the front-end electronics of BaBar vertex detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY AB The microstrip vertex detector in BaBar experiment will be read out by a purposely designed front-end chip. The chip performs amplification and analog-to-digital conversion to retain the information of the charge induced on the readout strips. It stores the digital data during the trigger latency time and associates the incoming trigger with the relevant hit data, Data are buffered and sent off in sparsified form when a readout command is received. The present paper discusses the signal processing performed by the chip. C1 UNIV PAVIA,DIPARTIMENTO ELETTR,I-27100 PAVIA,ITALY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF SANTA CRUZ,INST PARTICLE PHYS,SANTA CRUZ,CA 95064. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. OI Re, Valerio/0000-0003-0697-3420 NR 3 TC 15 Z9 15 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 1 PY 1996 VL 377 IS 2-3 BP 459 EP 464 DI 10.1016/0168-9002(96)00251-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600043 ER PT J AU Lund, JC Olsen, RW James, RB VanScyoc, JM Eissler, EE Blakeley, MM Glick, JB Johnson, CJ AF Lund, JC Olsen, RW James, RB VanScyoc, JM Eissler, EE Blakeley, MM Glick, JB Johnson, CJ TI Performance of a coaxial geometry Cd1-xZnxTe detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY AB For many years, coaxial geometry detectors have been the preferred configuration for large volume high purity germanium detectors. Recently, developments in Cd1-xZnxTe crystal growth and detector fabrication have enabled the construction of coaxial geometry Cd1-xZnxTe detectors for the first time. We report on the performance of a coaxial geometry Cd1-xZnxTe detector operated as a gamma ray spectrometer. The pulse height spectra obtained from this detector were analyzed using a theory developed by Sakai for use with germanium detectors and good agreement was obtained between the predictions of Sakai's theory and the results measured in our laboratory. We also comment on some possible improvements that could be made to future coaxial geometry Cd1-xZnxTe detectors. C1 EV PROD,SAXONBURG,PA 16056. RP Lund, JC (reprint author), SANDIA NATL LABS,MS 9162,LIVERMORE,CA 94551, USA. NR 5 TC 10 Z9 10 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 1 PY 1996 VL 377 IS 2-3 BP 479 EP 483 DI 10.1016/0168-9002(96)00256-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600047 ER PT J AU Schieber, M Lund, JC Olsen, RW McGregor, DS VanScyoc, JM James, RB Soria, E Bauser, E AF Schieber, M Lund, JC Olsen, RW McGregor, DS VanScyoc, JM James, RB Soria, E Bauser, E TI Material properties and room-temperature nuclear detector response of wide bandgap semiconductors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th European Symposium on Semiconductor Detectors CY MAY 07-JUL 10, 1995 CL SCHLOSS ELMAU, GERMANY ID MERCURIC IODIDE AB Several semiconductor materials for room-temperature X-ray and gamma-ray detectors, including HgI2, Cd1-xZnxTe (CZT), GaAs, and PbI2 have been studied at Sandia National Laboratories, California. A comparison of the spectral response of these detectors will be given and related to material properties, such as charge carrier drift length, crystal purity, structural perfection, acid material stoichiometry, as well as to the crystal growth techniques and device fabrication processes published elsewhere. Room-temperature detector spectral responses for each of these materials are presented, for photon energies in the range of 5.9 to 662 keV. CZT and HgI2 detectors demonstrate excellent energy resolution over the entire energy range, while PbI2 detectors exhibit reasonable response only up to about 30 keV. Some of the semi-insulating GaAs detectors fabricated from vertical gradient freeze materials show good spectral resolution for lower energies up to similar to 60 keV, whereas other SI-GaAs detectors studied at Sandia function only as counters. Finally, some predictions on the future materials development of these wide bandgap semiconductors for room-temperature radiation detector applications will be discussed. C1 SANDIA NATL LABS,MAT DEV & DIAGNOST,LIVERMORE,CA 94550. MAX PLANCK INST FESTKORPERFORSCH,D-70506 STUTTGART,GERMANY. HEBREW UNIV JERUSALEM,JERUSALEM,ISRAEL. RP Schieber, M (reprint author), SANDIA NATL LABS,ADV ELECTR MFG TECHNOL,MS 9162,LIVERMORE,CA 94550, USA. NR 13 TC 16 Z9 20 U1 1 U2 4 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 1 PY 1996 VL 377 IS 2-3 BP 492 EP 495 DI 10.1016/0168-9002(96)00030-7 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VA996 UT WOS:A1996VA99600050 ER PT J AU Zappala, A Bajt, S Gigante, GE Hanson, AL AF Zappala, A Bajt, S Gigante, GE Hanson, AL TI Applications of EDXRF in the conservation of acid papers using a synchrotron light microbeam SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID RADIATION AB Paper can be produced from various raw materials, which give rise to differences in the permanence and durability of the paper product, Modern paper is characterised by a tendency to discolor and become brittle, both problems being generally related to the high acidity of these papers, In order to avoid the loss of historical paper documents to this discoloration and embrittlement, many approaches have been developed to deacidify the high acid papers, However, there is a problem to verify the effectiveness of the different strategies. For this work a synchrotron X-ray microprobe was used to study the distributions of elements, related to the deacidification treatments, within papers treated with specific processes. These elemental distributions can serve as indicators of the effectiveness of each individual process. The microprobe is located at beamline X-26A at the Brookhaven National Laboratory, National Synchrotron Light Source and utilised a 7 X 10 mu m(2) collimated beam of X-rays from the synchrotron. Scans were performed transverse to paper sections to obtain elemental distribution through the sample, Some preliminary results of measurements on treated and untreated paper samples are presented. C1 UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. UNIV UDINE,DIPARTIMENTO STORIA & TUTELA BENI CULTURALI,I-33100 UDINE,ITALY. UNIV CHICAGO,CTR ADV RADIAT SOURCES,CHICAGO,IL 60637. BROOKHAVEN NATL LAB,CHICAGO,IL. RI Bajt, Sasa/G-2228-2010; OI Gigante, Giovanni Ettore/0000-0001-5943-9366 NR 8 TC 6 Z9 7 U1 0 U2 2 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 AUG PY 1996 VL 117 IS 1-2 BP 145 EP 150 DI 10.1016/0168-583X(96)00221-2 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VC427 UT WOS:A1996VC42700024 ER PT J AU Pedersen, D Weller, RA Weller, MR Montemayor, VJ Banks, JC Knapp, JA AF Pedersen, D Weller, RA Weller, MR Montemayor, VJ Banks, JC Knapp, JA TI Sputtering and migration of trace quantities of transition metal atoms on silicon SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID BACKSCATTERING; SPECTROMETRY; SENSITIVITY AB We have investigated the behavior of low levels of transition metal atoms on silicon surfaces subject to nitrogen bombardment. Submonolayer coverages of gold, iron, copper, molybdenum and tungsten were deposited on [100] silicon surfaces. Samples were analyzed using 270 keV He+ time-of-flight backscattering before and after irradiation with 6 mC of 270 keV N+ at current levels in the hundreds of nanoamps. The yield of sputtered metallic atoms ranged from 1.0 X 10(-3) per incident nitrogen ion to 3.3 X 10(-3) per incident ion. Lower yields were correlated with migration of the metallic species into the silicon. The implications for ultra-high sensitivity measurement of contamination on silicon wafers by time-of-flight heavy-ion backscattering spectrometry are discussed. C1 VANDERBILT UNIV,NASHVILLE,TN 37235. MIDDLE TENNESSEE STATE UNIV,MURFREESBORO,TN 37132. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 9 TC 3 Z9 3 U1 0 U2 2 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 AUG PY 1996 VL 117 IS 1-2 BP 170 EP 174 DI 10.1016/0168-583X(96)00225-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VC427 UT WOS:A1996VC42700028 ER PT J AU Sickafus, KE Yu, N Nastasi, M AF Sickafus, KE Yu, N Nastasi, M TI Radiation resistance of the oxide spinel: The role of stoichiometry on damage response SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 8th International Conference on Radiation Effects in Insulators (REI-8) - Beam Interactions with Materials and Atoms CY SEP 11-15, 1995 CL CATANIA, ITALY SP Catania Univ, Phys Dept, Catania Univ, Dept Chem Sci, Catania Ric Consortium ID NEUTRON-IRRADIATION DAMAGE; ION-IRRADIATION; CERAMICS AB Stoichiometric and non-stoichiometric magnesio-aluminate spinel single crystals (compositions MgO . Al2O3 and MgO . 3Al(2)O(3), respectively) were irradiated with both 400 keV and 1.5 MeV Xe ions under cryogenic and room temperature conditions, in order to compare the irradiation damage response of these isostructural compounds. Overall, stoichiometric spinel was found to be more resistant to irradiation damage (microstructural alterations) than the non-stoichiometric compound. At room temperature, non-stoichiometric spinel transforms to a metastable crystalline structure at an ion dose representing 1 to 2 displacements per atom (dpa), while this transformation is not observed in stoichiometric spinel to a dose of 10 dpa. Furthermore, under cryogenic conditions, both stoichiometric and non-stoichiometric spinel undergo a metastable phase transformation, followed by a transformation to an aperiodic structure, and they do so at similar ion doses. RP Sickafus, KE (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. NR 17 TC 30 Z9 30 U1 1 U2 6 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 AUG PY 1996 VL 116 IS 1-4 BP 85 EP 91 DI 10.1016/0168-583X(96)00015-8 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VG592 UT WOS:A1996VG59200016 ER PT J AU Zinkle, SJ Snead, LL AF Zinkle, SJ Snead, LL TI Influence of irradiation spectrum and implanted ions on the amorphization of ceramics SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 8th International Conference on Radiation Effects in Insulators (REI-8) - Beam Interactions with Materials and Atoms CY SEP 11-15, 1995 CL CATANIA, ITALY SP Catania Univ, Phys Dept, Catania Univ, Dept Chem Sci, Catania Ric Consortium ID SIC SINGLE-CRYSTALS; TO-AMORPHOUS TRANSITION; SILICON-CARBIDE; HIGH-RESOLUTION; MGAL2O4 SPINEL; DAMAGE; DISPLACEMENT; MICROSTRUCTURE; INSULATORS; ACCUMULATION AB Polycrystalline specimens of alumina (Al2O3), magnesium aluminate spinel (MgAl2O4), magnesia (MgO), silicon nitride (Si3N4) and silicon carbide (SiC) were irradiated with various ions at temperatures between 200 and 450 K, and the microstructures were examined following irradiation using cross section transmission electron microscopy. Amorphization was not observed in any of the irradiated oxide ceramics, despite damage energy densities up to similar to 70 keV/atom (similar to 70 displacements per atom). On the other hand, SiC readily amorphized after damage levels of similar to 0.4 dpa at room temperature. Silicon nitride exhibited intermediate behavior, irradiation with Fe ions at room temperature produced amorphization in the implanted ion region after damage levels of similar to 1 dpa. However, irradiated regions outside of the implanted ion region did not amorphize even after damage levels in excess of 5 dpa. The amorphous layer in the Fe-implanted region of Si3N4 did not appear if the specimen was simultaneously irradiated with 1 MeV He+ ions at room temperature. By comparison with published results, it is concluded that the implantation of certain chemical species has a pronounced effect on amorphization threshold dose of all five materials. Intense ionizing radiation inhibits amorphization in Si3N4, but does not appear to significantly influence the amorphization behavior of SiC. RP OAK RIDGE NATL LAB, DIV MET & CERAM, POB 2008, OAK RIDGE, TN 37831 USA. OI Zinkle, Steven/0000-0003-2890-6915 NR 59 TC 137 Z9 137 U1 10 U2 47 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X EI 1872-9584 J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD AUG PY 1996 VL 116 IS 1-4 BP 92 EP 101 DI 10.1016/0168-583X(96)00016-X PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VG592 UT WOS:A1996VG59200017 ER PT J AU McHargue, CJ Ren, SX Sklad, PS Allard, LF Hunn, J AF McHargue, CJ Ren, SX Sklad, PS Allard, LF Hunn, J TI Preparation of manometer-size dispersions of iron in sapphire by ion implantation and annealing SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 8th International Conference on Radiation Effects in Insulators (REI-8) - Beam Interactions with Materials and Atoms CY SEP 11-15, 1995 CL CATANIA, ITALY SP Catania Univ, Phys Dept, Catania Univ, Dept Chem Sci, Catania Ric Consortium AB Some of the metal ions implanted into sapphire (alpha-Al2O3) are often present as metallic colloids or dispersions. Nano-composites of iron colloids in sapphire were prepared by implantation of 160 keV Fe-56 at room temperature, The colloids were coarsened by annealing in the temperature range of 973 to 1673 K in a reducing atmosphere. Rutherford backscattering-ion channeling (RBS) and transmission electron microscopy (TEM) were used to determine the lattice damage as well as the nature, size and distribution of the iron. Second phase particles having diameters of 1-3 nm, and accounting for 45% of the implanted iron at a fluence of I x 10(17) Fe/cm(2) were identified by electron diffraction as having the alpha-Fe (body-centered cubic) structure. Annealing samples implanted at lower fluences produced metallic iron particles (3-20 nm diam.) with attached voids. The matrix was amorphous at 2 x 10(17) Fe/cm(2) and contained ''strings'' of crystalline iron particles (5-10 nm). Annealing in the reducing atmosphere produced iron platelets several hundreds nanometers long by 25-35 nm thick. It was observed that a range of particle sizes and shapes can be obtained by choice of implantation and/or annealing parameters. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP McHargue, CJ (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 5 TC 26 Z9 27 U1 0 U2 4 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 AUG PY 1996 VL 116 IS 1-4 BP 173 EP 177 DI 10.1016/0168-583X(96)00123-1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VG592 UT WOS:A1996VG59200033 ER PT J AU Weber, WJ Wang, LM Yu, N AF Weber, WJ Wang, LM Yu, N TI The irradiation-induced crystalline-to-amorphous phase transition in alpha-SiC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 8th International Conference on Radiation Effects in Insulators (REI-8) - Beam Interactions with Materials and Atoms CY SEP 11-15, 1995 CL CATANIA, ITALY SP Catania Univ, Phys Dept, Catania Univ, Dept Chem Sci, Catania Ric Consortium ID INDUCED AMORPHIZATION; SINGLE-CRYSTALS; SILICON-CARBIDE; TEMPERATURE; DEPENDENCE; IMPLANTATION; ENERGY AB The ion-beam-induced crystalline-to-amorphous phase transition in single crystal alpha-SiC has been studied as a function of irradiation temperature. The evolution of the amorphous state has been followed in situ in specimens irradiated with 1.5 MeV Xe+ ions over the temperature range from 20 to 475 K using the HVEM-tandem facility at Argonne National Laboratory. Specimens also have been irradiated at 170 and 370 K with 360 keV Ar+ ions, acid the damage accumulation process followed in situ by Rutherford backscattering spectroscopy in channeling geometry using dual-beam facilities at Los Alamos National Laboratory. The displacement dose for complete amorphization in alpha-SiC at 20 K is 0.25 dpa and increases with temperature in two stages, The simultaneous recovery process associated with the high-temperature stage(above 100 K) has an activation energy of 0.12 +/- 0.02 eV. The critical temperature above which amorphization does not occur is 485 K under these irradiation conditions. Dechanneling results are consistent with disordering occurring by the local accumulation of defects and show a decrease in disordering rate with increasing temperature. C1 UNIV NEW MEXICO,DEPT EARTH & PLANETARY SCI,ALBUQUERQUE,NM 87131. LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RP Weber, WJ (reprint author), PACIFIC NW NATL LAB,POB 999,RICHLAND,WA 99352, USA. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 20 TC 67 Z9 67 U1 1 U2 16 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 AUG PY 1996 VL 116 IS 1-4 BP 322 EP 326 DI 10.1016/0168-583X(96)00066-3 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VG592 UT WOS:A1996VG59200061 ER PT J AU Budinger, TF Brennan, KM Moses, WW Derenzo, SE AF Budinger, TF Brennan, KM Moses, WW Derenzo, SE TI Advances in positron tomography for oncology SO NUCLEAR MEDICINE AND BIOLOGY LA English DT Article; Proceedings Paper CT Conference on New Trends in Nuclear Oncology CY SEP 27-29, 1995 CL NAPLES, ITALY DE PET instrumentation; spatial resolution; annihilation photons; photon interactions; resolution components; crystal penetration; statistics ID MATHEMATICAL REMOVAL; RETRACTABLE SEPTA; EMISSION; PET; RESOLUTION; CAMERA AB Development of PET instrumentation over the past 42 years has moved from simple dual-detector coincidence scanners, to proposed systems having 60,000 detectors and simultaneous coverage of 15-cm regions of the body with spatial resolutions better than 4 mm. The principal determinants of positron emission tomography (PET) instrumentation advances are positron range, noncollinearity of the annihilation photons, scattering, random event rates, detector size, efficiency, speed and light output; capability to correct for depth of crystal interaction, attenuation compensation, axial coverage, and rapid data analysis and presentation. While general-purpose systems with 2-mm resolution are expected, special purpose PET devices are being built for breast and brain tumor studies with resolutions from 1.7 to 5 mm. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY NATL LAB, CTR FUNCT IMAGING, 1 CYCLOTRON RD, MAIL STOP 55-121, BERKELEY, CA 94720 USA. FU NHLBI NIH HHS [HL25840] NR 25 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0969-8051 EI 1872-9614 J9 NUCL MED BIOL JI Nucl. Med. Biol. PD AUG PY 1996 VL 23 IS 6 BP 659 EP 667 DI 10.1016/0969-8051(96)00063-7 PG 9 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA VH671 UT WOS:A1996VH67100003 PM 8940706 ER PT J AU Kaul, R Allen, M Bradbury, EM Wenman, WM AF Kaul, R Allen, M Bradbury, EM Wenman, WM TI Sequence specific binding of chlamydial histone H1-like protein SO NUCLEIC ACIDS RESEARCH LA English DT Article ID ESCHERICHIA-COLI; NUCLEOTIDE-SEQUENCE; DNA-REPLICATION; REGULATED GENE; TRACHOMATIS; H1; TRANSCRIPTION; PLASMID; HOMOLOG; EXPRESSION AB Chlamydia trachomatis is one of the few prokaryotic organisms known to contain proteins that bear homology to eukaryotic histone H1. Changes in macromolecular conformation of DNA mediated by the histone Hi-like protein (Hell appear to regulate stage specific differentiation, We have developed a cross-linking immunoprecipitation protocol to examine in vivo protein-DNA interaction by immune precipitating chlamydial Hcl cross linked to DNA, Our results strongly support the presence of sequence specific binding sites on the chlamydial plasmid and hcl gene upstream of its open reading frame, The preferential binding sites were mapped to 520 bp BamHI-XhoI and 547 bp BamHI-DraI DNA fragments on the plasmid and hcl respectively, Comparison of these two DNA sequences using Bestfit program has identified a 24 bp region with >75% identity that is unique to the chlamydial genome. Double-stranded DNA prepared by annealing complementary oligonucleotides corresponding to the conserved 24 bp region bind Hcl, in contrast to control sequences with similar A+T ratios, Further, Hcl binds to DNA in a strand specific fashion, with preferential binding for only one strand. The site specific affinity to plasmid DNA was also demonstrated by atomic force microscopy data images. Binding was always followed by coiling, shrinking and aggregation of the affected DNA, Very low protein-DNA ratio was required if incubations were carried out in solution, However, if DNA was partially immobilized on mica substrate individual strands with dark foci were still visible even after the addition of excess Hc1. C1 UNIV CALIF DAVIS,SCH MED,DEPT PEDIAT,DIV INFECT DIS,DAVIS,CA 95616. UNIV CALIF DAVIS,DEPT BIOL CHEM,DAVIS,CA 95616. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NR 41 TC 7 Z9 7 U1 0 U2 0 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD AUG 1 PY 1996 VL 24 IS 15 BP 2981 EP 2989 DI 10.1093/nar/24.15.2981 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VB832 UT WOS:A1996VB83200018 PM 8760883 ER PT J AU Parinov, S Barsky, V Yershov, G Kirillov, E Timofeev, E Belgovskiy, A Mirzabekov, A AF Parinov, S Barsky, V Yershov, G Kirillov, E Timofeev, E Belgovskiy, A Mirzabekov, A TI DNA sequencing by hybridization to microchip octa- and decanucleotides extended by stacked pentanucleotides SO NUCLEIC ACIDS RESEARCH LA English DT Article ID NUCLEIC-ACID HYBRIDIZATION; PRIMERS; 5-NITROINDOLE; STABILITY; HEXAMERS; ARRAYS; BASES AB The efficiency of sequencing by hybridization to an oligonucleotide microchip grows with an increase in the number and in the length of the oligonucleotides; however, such increases raise enormously the complexity of the microchip and decrease the accuracy of hybridization, We have been developing the technique of contiguous stacking hybridization (CSH) to circumvent these shortcomings, Stacking interactions between adjacent bases of two oligonucleotides stabilize their contiguous duplex with DNA, The use of such stacking increases the effective length of microchip oligonucleotides, enhances sequencing accuracy and allows the sequencing of longer DNA. The effects of mismatches, base composition, length and other factors on the stacking are evaluated, Contiguous stacking hybridization of DNA with immobilized 8mers and one or two 5mers labeled with two different fluorescent dyes increases the effective length of sequencing oligonucleotides from 8 to 13 and 18 bases, respectively, The incorporation of all four bases or 5-nitroindole as a universal base into different positions of the Smers permitted a decrease in the number of additional rounds of hybridization, Contiguous stacking hybridization appears to be a promising approach to significantly increasing the efficiency of sequencing by hybridization. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. VA ENGELHARDT MOL BIOL INST,JOINT HUMAN GENOME PROGRAM,MOSCOW 117984,RUSSIA. NR 23 TC 76 Z9 79 U1 1 U2 7 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD AUG 1 PY 1996 VL 24 IS 15 BP 2998 EP 3004 DI 10.1093/nar/24.15.2998 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VB832 UT WOS:A1996VB83200020 PM 8760885 ER PT J AU Smith, RE Warren, ME Wendt, JR Vawter, GA AF Smith, RE Warren, ME Wendt, JR Vawter, GA TI Polarization-sensitive subwavelength antireflection surfaces on a semiconductor for 975 nm SO OPTICS LETTERS LA English DT Article ID GRATINGS AB We present the results of subwavelength antireflection surfaces etched into GaAs for use at 975 nm. These surfaces comprise linear gratings with periods less than the wavelength of light in GaAs. The structure appears as a homogeneous birefringent film. For one of the two polarizations, the film is directly analogous to the well-known quarter-wavelength antireflection coating. For the other polarization there is little effect on the surface reflectivity. (C) 1996 Optical Society of America RP Smith, RE (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 11 TC 26 Z9 27 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD AUG 1 PY 1996 VL 21 IS 15 BP 1201 EP 1203 DI 10.1364/OL.21.001201 PG 3 WC Optics SC Optics GA UZ825 UT WOS:A1996UZ82500037 PM 19876299 ER PT J AU Mei, J Cooper, BR Lawson, AC Roberts, JA Cotton, JD AF Mei, J Cooper, BR Lawson, AC Roberts, JA Cotton, JD TI Atom-specific thermal vibration amplitudes in stoichiometric NiAl: Agreement of neutron diffraction and ab initio-based molecular dynamics SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID POWDER DIFFRACTION; DEBYE TEMPERATURES AB The use of Rietveld refinement using powder neutron diffraction data provides a unique means to measure the atom-species-specific mean square thermal displacements; while molecular dynamics (MD) using ab initio-based atomistic potentials provides a means of calculating predictively these same quantities without any fitting or use of experimental data whatsoever. In this paper application of this neutron-diffraction-based technique to a metallic system is reported for the first time and it is found that the differences in thermal amplitudes for Ni and Al are in close agreement with our ab initio-based MD predictions, and that absolute values are about a third greater. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87546. RP Mei, J (reprint author), W VIRGINIA UNIV,DEPT PHYS,MORGANTOWN,WV 26506, USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD AUG PY 1996 VL 74 IS 2 BP 169 EP 175 DI 10.1080/01418639608240334 PG 7 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VB667 UT WOS:A1996VB66700004 ER PT J AU Larese, JZ Asmussen, B Adams, MA Carlile, C Martin, D Ferrand, M AF Larese, JZ Asmussen, B Adams, MA Carlile, C Martin, D Ferrand, M TI Rotational tunneling studies of methane films adsorbed on MgO: Crossover from two-to-three dimensions? SO PHYSICA B LA English DT Article; Proceedings Paper CT International Workshop on Quantum Tunnelling of Atoms and Molecules in Solids (QTAMS 95) CY OCT 04-07, 1995 CL CHATEAU BAUME, SEYSSINS, FRANCE SP ILL, CNRS HO CHATEAU BAUME ID NEUTRON-SCATTERING; SURFACE AB High-resolution inelastic neutron scattering techniques have been used to investigate the rotational tunneling properties of methane films adsorbed on the (100) face of MgO surfaces. The monolayer solid forms a square-root 2 x root 2 R45 degrees commensurate lattice. Methane vapor pressure isotherms and elastic diffraction studies indicate that four or five discrete layering transitions occur. Results will be presented which illustrate the tunneling properties of monolayer and bilayer CH4. The possibility of observing a crossover from two-dimensional to three-dimensional behavior will also be discussed. C1 CHRISTIAN ALBRECHTS UNIV KIEL,INST EXPT PHYS,D-2300 KIEL,GERMANY. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. INST MAX VON LAUE PAUL LANGEVIN,GRENOBLE,FRANCE. RP Larese, JZ (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Martin y Marero, David/B-3094-2008 OI Martin y Marero, David/0000-0002-8969-0735 NR 7 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD AUG PY 1996 VL 226 IS 1-3 BP 221 EP 223 DI 10.1016/0921-4526(96)00308-0 PG 3 WC Physics, Condensed Matter SC Physics GA VH548 UT WOS:A1996VH54800040 ER PT J AU Nilsen, J Beiersdorfer, P Widmann, K Decaux, V Elliott, SR AF Nilsen, J Beiersdorfer, P Widmann, K Decaux, V Elliott, SR TI Energies of neon-like n=4 to n=2 resonance lines SO PHYSICA SCRIPTA LA English DT Article ID HIGHLY CHARGED IONS; X-RAY-SPECTRA; ISOELECTRONIC SEQUENCE; SELF-ENERGY; LAMB SHIFT; TRANSITIONS; SPECTROSCOPY; LASERS; ATOMS; IRON AB A multi-configuration Dirac-Fock method is used to calculate the energies of the n = 4 --> n = 2 resonance lines for neon-like ions with nuclear charge Z from 18 to 92. These results are compared with calculations done by the Z-expansion method and the model potential method. High resolution measurements done at the EBIT facility are presented for several high-Z ions and provide an important benchmark against which the various code results are compared. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 34 TC 5 Z9 5 U1 2 U2 3 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD AUG PY 1996 VL 54 IS 2 BP 183 EP 187 DI 10.1088/0031-8949/54/2/012 PG 5 WC Physics, Multidisciplinary SC Physics GA VB290 UT WOS:A1996VB29000012 ER PT J AU Benioff, P AF Benioff, P TI Quantum ballistic evolution in quantum mechanics: Application to quantum computers SO PHYSICAL REVIEW A LA English DT Article ID TURING-MACHINES; COMPUTATION; UNIVERSAL; MODELS; GATE AB Quantum computers are important examples of processes M-hose evolution can be described in terms of iterations of single-step operators or their adjoints. Based on this, Hamiltonian evolution of processes with associated step operators T is investigated here. The main limitation of this paper is to processes which evolve quantum ballistically, i.e., motion restricted to a collection of nonintersecting or distinct paths on an arbitrary basis. The main goal of this paper is proof of a theorem which gives necessary and sufficient conditions that T must satisfy so that there exists a Hamiltonian description of quantum ballistic evolution for the process, namely, that T is a partial isometry and is orthogonality preserving and stable on some basis. Simple examples of quantum ballistic evolution for quantum Turing machines with one and with more than one type of elementary step are discussed. It is seen that for nondeterministic machines the basis set can be quite complex with much entanglement present. It is also proven that, given a step operator T for an arbitrary deterministic quantum Turing machine, it is decidable if T is stable and orthogonality preserving, and if quantum ballistic evolution is possible. The proof fails if T is a step operator for a nondeterministic machine, it is an open question if such a decision procedure exists for nondeterministic machines. This problem does not occur in classical mechanics. Also the definition of quantum Turing machines used here is compared with that used by other authors. RP Benioff, P (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 45 TC 15 Z9 15 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1996 VL 54 IS 2 BP 1106 EP 1123 DI 10.1103/PhysRevA.54.1106 PG 18 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VD676 UT WOS:A1996VD67600017 ER PT J AU Segner, F Breinig, M Desai, DD Wig, A Straus, L AF Segner, F Breinig, M Desai, DD Wig, A Straus, L TI Recoil-ion charge-state-resolved electron-production cross sections at 55 degrees for 1 MeV/u C5+ on He and Ar SO PHYSICAL REVIEW A LA English DT Article ID BINARY-ENCOUNTER ELECTRONS; ATOM COLLISIONS; ANGULAR-DISTRIBUTION; PEAK; IONIZATION; DEPENDENCE; ENERGY; 0-DEGREES; PARTICLES; EMISSION AB Recoil-ion charge-state-resolved doubly differential cross sections for ejecting electrons at similar to 55 degrees with respect to the incident beam direction in collisions between 1 MeV/u C5+ projectiles and Ar and He targets have been measured. Electrons with kinetic energies between 100 and 1250 eV have been detected. A prominent feature in the electron energy distributions is the binary-encounter peak. Experimental results are compared with binary-encounter electron production cross sections obtained using the impulse approximation and with theoretical predictions from many-body classical trajectory Monte Carlo calculations. An enhancement in the fraction of electrons detected with singly charged He recoil ions and a corresponding decrease in the fraction detected in coincidence with doubly charged He recoil ions as a function of the electron energy have been observed near the binary-encounter electron energy. This structure has been predicted by recent many-body classical trajectory Monte Carlo calculations. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Segner, F (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 30 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1996 VL 54 IS 2 BP 1385 EP 1393 DI 10.1103/PhysRevA.54.1385 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VD676 UT WOS:A1996VD67600042 ER PT J AU Kravis, SD Abdallah, M Cocke, CL Lin, CD Stockli, M Walch, B Wang, YD Olson, RE Rodriguez, VD Wu, W Pieksma, M Watanabe, N AF Kravis, SD Abdallah, M Cocke, CL Lin, CD Stockli, M Walch, B Wang, YD Olson, RE Rodriguez, VD Wu, W Pieksma, M Watanabe, N TI Single ionization of He by low-velocity protons and C6+: Ejected electron momentum distributions SO PHYSICAL REVIEW A LA English DT Article ID ION-ATOM COLLISIONS; DIFFERENTIAL CROSS-SECTIONS; SADDLE-POINT ELECTRONS; HIGHLY-CHARGED IONS; IONIZING COLLISIONS; PROJECTILE-CHARGE; IMPACT; EMISSION; HYDROGEN; ENERGY AB A technique for electron spectroscopy which yields full two-dimensional momentum distributions for continuum electrons has been used to study ejected electrons from single ionization of lie by C6+ and proton projectiles at low velocities. Projectile velocities of 1.63, 1.38, and 1.16 a.u, for C6+ and 2.39, 1.71, 1.15, .85, and 0.63 a.u. for protons were used. All spectra show much broader distributions along the beam than transverse to the beam. For the case of proton bombardment, the spectra are strongly influenced by both target and projectile potentials, maximizing near the velocity of the saddle in the potential between the two, receding ion cores for the lowest projectile velocities. For C6+ projectiles, the spectra appear to be dominated by the projectile potential and the center of the distribution is strongly shifted toward the projectile velocity. Theoretical results from the continuum-distorted-wave-eikonal-initial state and classical-trajectory-Monte Carlo methods are in rather good agreement with the proton data but do not agree well with the C6+ data. C1 UNIV MISSOURI,ATOM & MOL RES LAB,ROLLA,MO 65439. UNIV MISSOURI,DEPT PHYS,ROLLA,MO 65439. UNIV BUENOS AIRES,DEPT FIS,RA-1428 BUENOS AIRES,DF,ARGENTINA. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RIKEN,INST PHYS & CHEM RES,WAKO,SAITAMA 35101,JAPAN. RP Kravis, SD (reprint author), KANSAS STATE UNIV,DEPT PHYS,JR MACDONALD LAB,MANHATTAN,KS 66506, USA. RI WATANABE, Naoki/A-7451-2012; Lin, c d/D-7312-2012 OI Lin, c d/0000-0003-4847-8938 NR 31 TC 44 Z9 44 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 AUG PY 1996 VL 54 IS 2 BP 1394 EP 1403 DI 10.1103/PhysRevA.54.1394 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VD676 UT WOS:A1996VD67600043 ER PT J AU Bannister, ME AF Bannister, ME TI Absolute cross sections for electron-impact single ionization of Ne-q+ (q=2,4-6) ions SO PHYSICAL REVIEW A LA English DT Article ID BE-LIKE IONS; GAS IONS; NE-2+; AR-2+; KR-2+; XE-2+; VII AB Absolute total cross sections for electron-impact single ionization of Ne-q+ (q=2,4-6) ions have been measured using a crossed-beams technique from below the ground-state ionization threshold to 800 eV with typical total uncertainties near the peak of the cross sections ranging from 9% for Ne2+ to 13% for Ne6+. Details of the apparatus and experimental procedures used in this study are presented along with a discussion of the experimental uncertainties. The measured cross sections for all four ions are dominated by direct ionization and are in excellent agreement with the Lotz semiempirical formula. Ionization rate coefficients and fitting parameters calculated from the measured cross sections are also reported. RP Bannister, ME (reprint author), OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831, USA. OI Bannister, Mark E./0000-0002-9572-8154 NR 27 TC 43 Z9 43 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1996 VL 54 IS 2 BP 1435 EP 1444 DI 10.1103/PhysRevA.54.1435 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VD676 UT WOS:A1996VD67600047 ER PT J AU Shaw, PS Arp, U Southworth, SH AF Shaw, PS Arp, U Southworth, SH TI Measuring nondipolar asymmetries of photoelectron angular distributions SO PHYSICAL REVIEW A LA English DT Article ID SYNCHROTRON RADIATION; CROSS-SECTIONS; PHOTOIONIZATION; SPECTROMETER; RETARDATION; PARAMETERS; MULTIPOLE AB In theories of photoelectron angular distributions at soft-x-ray energies from 1 to 10 keV, first-order corrections to the dipole approximation give rise to two nondipolar asymmetry parameters in addition to the well-known dipolar asymmetry parameter beta. The nondipolar parameters characterize the forward-backward asymmetry with respect to the propagation vector of the photon beam. Experimentally, the measurement of the nondipolar effect has been hampered because of the complications resulting from the three-parameter angular distribution. In this paper, we suggest various experimental approaches to the measurement of the three asymmetry parameters using partially linearly polarized x rays, corresponding to measurements on synchrotron radiation; beamlines. We describe methods to extract the asymmetry parameters using such approaches. C1 NATL INST STAND & TECHNOL,QUANTUM METROL DIV,GAITHERSBURG,MD 20899. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP Shaw, PS (reprint author), NATL INST STAND & TECHNOL,OPT TECHNOL DIV,GAITHERSBURG,MD 20899, USA. RI Arp, Uwe/C-2854-2009 NR 23 TC 26 Z9 26 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1996 VL 54 IS 2 BP 1463 EP 1472 DI 10.1103/PhysRevA.54.1463 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VD676 UT WOS:A1996VD67600052 ER PT J AU Martin, J Shore, BW Bergmann, K AF Martin, J Shore, BW Bergmann, K TI Coherent population transfer in multilevel systems with magnetic sublevels .3. Experimental results SO PHYSICAL REVIEW A LA English DT Article ID STIMULATED RAMAN-SCATTERING; ADIABATIC PASSAGE; VIBRATIONAL LEVELS; DELAYED PULSES; LASER-PULSES; BEAM; INVERSION; CONTINUUM; LIGHT AB The technique of stimulated Raman adiabatic passage (STIRAP) has become an established procedure for producing complete population inversion in atoms or molecules via application of Stokes and pump pulses in a counterintuitive sequence. Previously we reported on numerical and analytical investigations showing some of the additional and important phenomena that arise when some of the levels involved have nonzero angular momentum, the field polarization directions have no simplifying symmetries, and Zeeman splitting lifts the magnetic sublevel degeneracy. Here we verify our theoretical findings using the metastable neon system: P-3(0) double left right arrow(3)P(1) double left right arrow(3)P(2) with the corresponding angular momentum sequence J=0 double left right arrow J=1 double left right arrow J=2. In particular, we demonstrate that it is possible to transfer ail population from the single initial state to any single selectable final magnetic sublevel M. Selectivity can be achieved either by choosing special laser polarization angles or, for fixed polarizations, by tuning the two lasers into two-photon resonance between the initial and desired final state. The complete control of magnetic sublevel population enabled by this procedure extends the customary experimental methods for producing oriented or aligned beams of atoms. In addition, we demonstrate very clearly the previous prediction that population transfer may fail for certain sets of parameters (detunings, Rabi frequencies, and polarization angles). C1 UNIV KAISERSLAUTERN,FACHBEREICH PHYS,D-67653 KAISERSLAUTERN,GERMANY. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RI BERGMANN, KLAAS/D-5543-2011 NR 28 TC 101 Z9 101 U1 0 U2 11 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 AUG PY 1996 VL 54 IS 2 BP 1556 EP 1569 DI 10.1103/PhysRevA.54.1556 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VD676 UT WOS:A1996VD67600064 ER PT J AU Shi, ZP Cooke, JF Zhang, ZY Klein, BM AF Shi, ZP Cooke, JF Zhang, ZY Klein, BM TI Structural, magnetic, and electronic properties of Fe/Au monatomic multilayers SO PHYSICAL REVIEW B LA English DT Article ID FE-PT; SUPERLATTICES; FERROMAGNETS; INTERFACES; ALLOYS; L1(0); PD AB An Fe/Au monatomic multilayer, consisting of alternating single Fe and An layers, has been studied by means of the self-consistent full-potential linearized augmented plane wave method. We show by total energy minimization that this artificial thin film is in the tetragonal L1(0) ordered structure with the ratio of the interlayer spacing to the intralayer lattice constant at 0.865. In this configuration, the magnetic moment in each monolayer, the spin-polarized electronic density of slates, and the corresponding band structure are calculated. The results;ire discussed in connection with recent experiments. C1 UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP Shi, ZP (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 19 TC 23 Z9 23 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 5 BP 3030 EP 3032 DI 10.1103/PhysRevB.54.3030 PG 3 WC Physics, Condensed Matter SC Physics GA VC596 UT WOS:A1996VC59600018 ER PT J AU Zinkin, MP McMorrow, DF Hill, JP Cowley, RA Lussier, JG Gibaud, A Grubel, G Sutter, C AF Zinkin, MP McMorrow, DF Hill, JP Cowley, RA Lussier, JG Gibaud, A Grubel, G Sutter, C TI Synchrotron x-ray-scattering study of the normal-incommensurate phase transition in Rb2ZnCl4 SO PHYSICAL REVIEW B LA English DT Article ID 2 LENGTH SCALES; MAGNETIC CRITICAL FLUCTUATIONS; CRITICAL-BEHAVIOR; NEUTRON-SCATTERING; SRTIO3; SYSTEMS; HOLMIUM; ORIGIN; ERBIUM; POINT AB The results of high-resolution synchrotron x-ray-scattering experiments on the normal-incommensurate phase transition in Rb2ZnCl4 are reported. Measured critical exponents for the intensities of the first three harmonics of the incommensurate modulation wave below T-c agree well with theoretical predictions for the n=2, D=3 (SD-XY) universality class. The scattering observed above T-c corrresponds to critical fluctuations on two distinct length scales: the critical exponents for the short length scale component of the scattering agree with those expected for the 3D-XY universality class. The value found for the exponent of the inverse correlation length of the long length scale component is nu(s)=0.7+/-0.2. A comparison of data taken in Laue and Bragg geometries at different photon energies suggests that the second length scale scattering originates in the near-surface region. Possible explanations of the two length scale behavior are discussed. C1 RISO NATL LAB,DEPT SOLID STATE PHYS,DK-4000 ROSKILDE,DENMARK. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV MAINE,FAC SCI,URA 807 CNRS,F-72017 LE MANS,FRANCE. EUROPEAN SYNCHROTRON RADIAT FACIL,F-38043 GRENOBLE,FRANCE. RP Zinkin, MP (reprint author), UNIV OXFORD,CLARENDON LAB,PARKS RD,OXFORD OX1 3PU,ENGLAND. RI McMorrow, Desmond/C-2655-2008 OI McMorrow, Desmond/0000-0002-4947-7788 NR 33 TC 15 Z9 15 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 5 BP 3115 EP 3124 DI 10.1103/PhysRevB.54.3115 PG 10 WC Physics, Condensed Matter SC Physics GA VC596 UT WOS:A1996VC59600036 ER PT J AU Kerr, WC Butler, EN AF Kerr, WC Butler, EN TI Self-consistent mean-field theory of asymmetric first-order structural phase transitions SO PHYSICAL REVIEW B LA English DT Article ID 1ST-ORDER; FLUCTUATIONS AB The paper presents a self-consistent mean-field theory for a lattice-dynamical model that exhibits a first-order structural phase transition. in this model the phase transition is produced because the high-energy structure has lower vibrational frequencies than those of the low-energy structure. This mechanism produces higher entropy in the higher-energy structure and thereby drives a phase transition. These structure-dependent frequencies are produced by anharmonicity in the interparticle interaction, The approximate theory of the transition given here reduces the exact coupled equations of motion to a single mean-field equation by replacing coupling terms between neighbors with appropriate averages. This step produces an effective potential that is used to calculate self-consistently the averages that appear in it. Thermodynamic properties calculated by this method show that the system has a first-order phase transition for sufficiently large strength of the interparticle anharmonicity. Further properties of the system obtained by this method include a discontinuous change in the shape of the average displacement and free-energy vs temperature relations as a function of the anharmonicity strength. This feature may be related to the hysteresis seen in previously performed computer simulations on the model, The effective potential also determines the displacement probability distribution function. For the parameter values studied here this distribution has a single maximum with only small asymmetry above this maximum. C1 WAKE FOREST UNIV,OLIN PHYS LAB,WINSTON SALEM,NC 27109. RP Kerr, WC (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 5 BP 3184 EP 3199 DI 10.1103/PhysRevB.54.3184 PG 16 WC Physics, Condensed Matter SC Physics GA VC596 UT WOS:A1996VC59600044 ER PT J AU Jiang, X Ice, GE Sparks, CJ Robertson, L Zschack, P AF Jiang, X Ice, GE Sparks, CJ Robertson, L Zschack, P TI Local atomic order and individual pair displacements of Fe46.5Ni53.5 and Fe22.5Ni77.5 from diffuse x-ray scattering studies SO PHYSICAL REVIEW B LA English DT Article ID ABSORPTION FINE-STRUCTURE; MONTE-CARLO METHOD; SHORT-RANGE ORDER; SOLID-SOLUTIONS; ANOMALOUS DISPERSION; ALLOYS; INVAR; FE; NI; SPECTROSCOPY AB We have recovered the local atomic structures in a fee Fe46.5Ni53.5 solid solution near an equilibrium temperature of 600 degrees C with an improved version of the recently demonstrated three x-ray energy (3 lambda) method. We have also reevaluated the 3 lambda data from a Fe22.5Ni77.5 crystal which significantly changed the results. Both the Warren-Cowley short-range order parameters alpha and the first moment of the mean static displacements for Fe-Fe, Fe-Ni, and Ni-Ni pairs are recovered. Comparisons of the alpha's from Fe22.5Ni77.5 with neutron-scattering results show good agreement, and both compositions have alpha's with a strong similarity to those from Cu3Au quenched from above the ordering temperature. Displacements from the average lattice of less than 0.001 Angstrom can be recovered. For both Fe46.5Ni53.5 and Fe22.5Ni77.5 the average Fe-Fe first-neighbor distance of 2.564(5) Angstrom is much larger than the average derived from the lattice spacing for the alloys and is independent of concentration. However, the Ni-Ni, first-neighbor distance follows the average lattice, and the Fe-Ni first-neighbor distances are smaller than average. Both the Ni-Ni and Fe-Ni first-neighbor distances increase with Fe concentration. The relatively large and strongly chemically specific bond distances observed here may be a more meaningful concept for understanding the magnet properties of these Ni-rich alloys than the relative lesser change in volume of the Fe atom. RP OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. NR 70 TC 47 Z9 48 U1 0 U2 12 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 AUG 1 PY 1996 VL 54 IS 5 BP 3211 EP 3226 DI 10.1103/PhysRevB.54.3211 PG 16 WC Physics, Condensed Matter SC Physics GA VC596 UT WOS:A1996VC59600046 ER PT J AU Guo, MY Bhatt, RN Huse, DA AF Guo, MY Bhatt, RN Huse, DA TI Quantum Griffiths singularities in the transverse-field Ising spin glass SO PHYSICAL REVIEW B LA English DT Article ID ANTI-FERROMAGNETIC SYSTEMS; BEHAVIOR; MODEL; EQUILIBRIUM; RELAXATION; CHAINS AB We report a Monte Carlo study of the effects of fluctuations in the bond distribution of Ising spin glasses in a transverse magnetic field, in the paramagnetic phase In the T-->0 limit. Rare, strong fluctuations give rise to Griffiths singularities, which can dominate the zero-temperature behavior of these quantum systems, as originally demonstrated by McCoy for one-dimensional (d=1) systems. Our simulations are done on a square lattice in d=2 and a cubic lattice in d=3, for a Gaussian distribution of nearest neighbor (only) bonds. In d=2, where the linear susceptibility was found to diverge at the critical transverse field strength Gamma(c) for the order-disorder phase transition at T=0, the average nonlinear susceptibility chi(nl) diverges in the paramagnetic phase for Gamma well above Gamma(c), is is also demonstrated in the accompanying paper by Rieger and Young. In d=3, the linear susceptibility remains finite at Gamma(c), and while Griffiths singularity effects are certainly observable in the paramagnetic phase, the nonlinear susceptibility appears to diverge only rather close to Gamma(c). These results show that Griffiths singularities remain persistent in dimensions above one (where they are known to be strong), though their magnitude decreases monotonically with increasing dimensionality (there bring no Griffiths singularities in the limit of infinite dimensionality). C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP Guo, MY (reprint author), PRINCETON UNIV,DEPT ELECT ENGN,PRINCETON,NJ 08544, USA. NR 28 TC 73 Z9 73 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 5 BP 3336 EP 3342 DI 10.1103/PhysRevB.54.3336 PG 7 WC Physics, Condensed Matter SC Physics GA VC596 UT WOS:A1996VC59600059 ER PT J AU Abrikosov, IA James, P Eriksson, O Soderlind, P Ruban, AV Skriver, HL Johansson, B AF Abrikosov, IA James, P Eriksson, O Soderlind, P Ruban, AV Skriver, HL Johansson, B TI Magnetically induced crystal structure and phase stability in Fe1-cCoc SO PHYSICAL REVIEW B LA English DT Article ID GROUND-STATE PROPERTIES; GENERALIZED GRADIENT APPROXIMATION; TRANSITION-METALS; ELECTRONIC-STRUCTURE; BAND THEORY; FE-CO; ALLOYS; IRON; INSTABILITIES; DENSITY AB We present an ab initio determination of the crystallographic phase stability of Fe-Co alloys as a function of concentration, using the coherent potential approximation. A bcc --> hcp phase transition is found at a concentration of 85 at.% of Co, in good agreement with the experimental phase diagram. We demonstrate that for the Pe-rich random alloys magnetism-stabilizes the bce phase relative to the close-packed fee and hcp phases. Magnetism also favors the partially ordered alpha' phase relative to the random bce alloy. This unique relation between magnetism and phase stability for the Fe-Co alloys is analyzed by a spin-polarized canonical d-band model. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. TECH UNIV DENMARK, CTR ATOM SCALE MAT PHYS, DK-2800 LYNGBY, DENMARK. TECH UNIV DENMARK, DEPT PHYS, DK-2800 LYNGBY, DENMARK. RP Abrikosov, IA (reprint author), UNIV UPPSALA, DEPT PHYS, CONDENSED MATTER THEORY GRP, S-75121 UPPSALA, SWEDEN. RI Ruban, Andrei/B-7457-2012; Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 33 TC 59 Z9 59 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 5 BP 3380 EP 3384 DI 10.1103/PhysRevB.54.3380 PG 5 WC Physics, Condensed Matter SC Physics GA VC596 UT WOS:A1996VC59600063 ER PT J AU Grimsditch, M Kumar, S Fullerton, EE AF Grimsditch, M Kumar, S Fullerton, EE TI Brillouin light scattering study of Fe/Cr/Fe (211) and (100) trilayers SO PHYSICAL REVIEW B LA English DT Article ID INTERLAYER EXCHANGE; SANDWICH STRUCTURES; SPIN-WAVE; MAGNETORESISTANCE; SUPERLATTICES; CR; OSCILLATIONS; FE/CR(211); TRANSITION AB The magnitude of the bilinear and biquadratic interlayer coupling strengths between Fe layers separated by Cr spacer layers is investigated by means of Brillouin light scattering, magneto-optic Kerr rotation, and magnetoresistance techniques. A data analysis scheme, which treats all three data sets on an equal footing, yields self-consistent anisotropy and interlayer coupling parameters extracted independently from the three techniques. The values of the bilinear and biquadratic coupling strengths are compared for simultaneously grown (211) and (100) Fe/Cr samples. The approach not only provides reliable values for the coupling strengths but also highlights the complementarity of these techniques in uniquely determining the magnetic parameters. RP Grimsditch, M (reprint author), ARGONNE NATL LAB, DIV MAT SCI, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 25 TC 40 Z9 40 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 5 BP 3385 EP 3393 DI 10.1103/PhysRevB.54.3385 PG 9 WC Physics, Condensed Matter SC Physics GA VC596 UT WOS:A1996VC59600064 ER PT J AU Belanger, DP Wang, J Slanic, Z Han, SJ Nicklow, RM Lui, M Ramos, CA Lederman, D AF Belanger, DP Wang, J Slanic, Z Han, SJ Nicklow, RM Lui, M Ramos, CA Lederman, D TI Magnetic order in the random-field Ising film Fe0.52Zn0.48F2 SO PHYSICAL REVIEW B LA English DT Article ID LOWER CRITICAL DIMENSION; LONG-RANGE ORDER; NEUTRON-SCATTERING; CRITICAL-BEHAVIOR; INDUCED DOMAINS; MODEL; ANTIFERROMAGNETS; TRANSITION; CROSSOVER; SYSTEM AB The extinction-free neutron scattering for a 3.4 mu m epitaxial film of the dilute antiferromagnet Fe0.52Zn0.48F2 has been studied near The (100) antiferromagnetic Bragg point. For the H=0 Bragg scattering we observe the random-exchange Ising model behavior I similar to\t\(2 beta) with beta=0.35. For 00. The main feature of this construction is the absence of screening of the dissipative transversal gauge field generated by the spinons. This dissipative gauge field is responsible for the non-Fermi-liquid behavior, which is manifested in the free energy and single-particle Green function. The deviation from Fermi-liquid behavior is due to the U(1) gauge field, and at long distances a new exponent due to the holes is identified. Experimental consequences are discussed. C1 LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. RP CUNY CITY COLL, DEPT PHYS, NEW YORK, NY 10031 USA. NR 20 TC 1 Z9 1 U1 0 U2 0 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 AUG 1 PY 1996 VL 54 IS 6 BP 4293 EP 4299 DI 10.1103/PhysRevB.54.4293 PG 7 WC Physics, Condensed Matter SC Physics GA VD677 UT WOS:A1996VD67700089 ER PT J AU Bao, W Broholm, C Honig, JM Metcalf, P Trevino, SF AF Bao, W Broholm, C Honig, JM Metcalf, P Trevino, SF TI Itinerant antiferromagnetism in the Mott compound V1.973O3 SO PHYSICAL REVIEW B LA English DT Article ID SPIN-DENSITY-WAVE; ELECTRON FERROMAGNETISM; MAGNETIC FLUCTUATIONS; QUANTITATIVE ASPECTS; NEUTRON-SCATTERING; TEMPERATURE; NICKEL; SUPERCONDUCTIVITY; EXCITATIONS; DEPENDENCE AB The doping-induced metallic state of the Mott system V2-yO3 has spin-density-wave order for T centered at each antiferromagnetic Bragg point. The q, omega. and T dependence of magnetic fluctuations can be described by the self-consistent renormalization theory for weak itinerant antiferromagnets developed by Moriya, Hasegawa, and Nakayama. Thermodynamic properties below similar to 10T(N) are quantitatively accounted for by this theory in its simplest form with only four parameters, which are determined by our neutron-scattering experiment. C1 JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. PURDUE UNIV,W LAFAYETTE,IN 47907. USA,RES LAB,ADELPHI,MD 20783. RP Bao, W (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Broholm, Collin/E-8228-2011; Bao, Wei/E-9988-2011 OI Broholm, Collin/0000-0002-1569-9892; Bao, Wei/0000-0002-2105-461X NR 38 TC 25 Z9 25 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 6 BP R3726 EP R3729 PG 4 WC Physics, Condensed Matter SC Physics GA VD677 UT WOS:A1996VD67700015 ER PT J AU Dai, P Zhang, JD Mook, HA Liou, SH Dowben, PA Plummer, EW AF Dai, P Zhang, JD Mook, HA Liou, SH Dowben, PA Plummer, EW TI Experimental evidence for the dynamic Jahn-Teller effect in La0.65Ca0.35MnO3 SO PHYSICAL REVIEW B LA English DT Article ID DOUBLE-EXCHANGE; TRANSPORT-PROPERTIES; MAGNETORESISTANCE; LA1-XSRXMNO3; RESISTIVITY; TEMPERATURE; SYSTEMS; FILMS; MODEL AB Recently, it has been argued that a strong electron-phonon interaction arising from the Jahn-Teller splitting of the outer Mn d level plays a crucial role in understanding the nonmetal-to-metal transition observed in the La(1-x)A(x)MnO(3) (A = Ca,Sr,Ba) system. We show, by neutron powder diffraetion, that La0.65Ca0.35MnO3 exhibits an anomalous volume and oxygen/manganese displacement change around T-c, in qualitative agreement with the theoretical prediction. C1 UNIV NEBRASKA,DEPT PHYS & ASTRON,LINCOLN,NE 68588. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP Dai, P (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. RI Dai, Pengcheng /C-9171-2012 OI Dai, Pengcheng /0000-0002-6088-3170 NR 28 TC 234 Z9 241 U1 0 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 6 BP R3694 EP R3697 PG 4 WC Physics, Condensed Matter SC Physics GA VD677 UT WOS:A1996VD67700007 ER PT J AU Trivedi, N Scalettar, RT Randeria, M AF Trivedi, N Scalettar, RT Randeria, M TI Superconductor-insulator transition in a disordered electronic system SO PHYSICAL REVIEW B LA English DT Article ID COHERENCE LENGTH SUPERCONDUCTORS; U HUBBARD-MODEL; BOSE SYSTEMS; LOCALIZATION; FILMS; 2D AB We study an electronic model of a two-dimensional s-wave superconductor in a random potential using quantum Monte Carlo simulations. The superfluid density and the strength of the delta function in the optical conductivity are found to vanish beyond a critical disorder. We calculate the temperature-dependent resistivity rho(dc)(T) for a highly disordered interacting Fermi system, Using this we identify the nonsuperconducting state as an insulator. C1 TATA INST FUNDAMENTAL RES,THEORET PHYS GRP,BOMBAY 400005,MAHARASHTRA,INDIA. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP Trivedi, N (reprint author), ARGONNE NATL LAB,MAT SCI DIV 223,ARGONNE,IL 60439, USA. NR 22 TC 63 Z9 63 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 6 BP R3756 EP R3759 PG 4 WC Physics, Condensed Matter SC Physics GA VD677 UT WOS:A1996VD67700023 ER PT J AU Tyson, TA Conradson, SD Farrow, RFC Jones, BA AF Tyson, TA Conradson, SD Farrow, RFC Jones, BA TI Observation of internal interfaces in PtxCo1-x(x approximate to 0.7) alloy films: A likely cause of perpendicular magnetic anisotropy SO PHYSICAL REVIEW B LA English DT Article ID CO-PT; CO/PT MULTILAYERS; PHASE-TRANSITION; MBE-GROWTH; FE FILMS; MICROSTRUCTURE; CROSSOVER; UHV AB X-ray-absorption measurements of the local structure about Pt and Co in thin polycrystalline Pt0.72Co0.28 alloy films, which exhibit perpendicular magnetic anisotropy, indicate that the gross structure is fee. However. the data reveal a directional anisotropy in the number of Co-Co bonds with an excess of Co-Co bonds in the film plane, consistent with two-dimensional clustering of Co. The resulting internal interfaces are analogous to those in Co/Pt multilayers suggesting a similar mechanism for the perpendicular magnetic anisotropy in these alloys. C1 IBM CORP,DIV RES,ALMADEN RES CTR,SAN JOSE,CA 95120. RP Tyson, TA (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 43 TC 79 Z9 81 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 6 BP R3702 EP R3705 PG 4 WC Physics, Condensed Matter SC Physics GA VD677 UT WOS:A1996VD67700009 ER PT J AU Yatskar, A Budraa, NK Beyermann, WP Canfield, PC Budko, SL AF Yatskar, A Budraa, NK Beyermann, WP Canfield, PC Budko, SL TI Heavy-electron behavior in single-crystal YbNi2B2C SO PHYSICAL REVIEW B LA English DT Article ID BULK SUPERCONDUCTIVITY; STATE; MAGNETISM; TMNI2B2C; HONI2B2C; YBBIPT AB We have measured the magnetic susceptibility, specific heat, and electrical resistivity on single crystals of the intermetallic borocarbide YbNi2B2C. An enhanced linear contribution is observed in the specific heat with a Sommerfeld coefficient of 530 mJ/mol K-2, indicative of a heavy-electron system with a Kondo temperature similar to 10 K. The magnetic susceptibility, which is anisotropic and Curie-Weiss-like at high temperature, is also consistent with our interpretation of a strongly correlated ground state at low temperatures and crystal-electric-field excitations at higher temperatures. At T=1.8 K, the Wilson ratio is determined to be: 0.85 using the high-temperature effective moment. The resistivity shows a quadratic temperature dependence below 1.5 K with a T-2 coefficient of 1.2 mu Omega cm K-2. Unlike the other members of the series RNi(2)B(2)C (R=Y. Gd-Lu), YbNi2B2C does not order above our lowest measurement temperature of 0.34 K. The suppression of superconductivity in YbNi2B2C is consistent with a significantly enhanced hybridization between the conduction electrons and the 4f states. C1 AMES LAB,AMES,IA 50011. IOWA STATE UNIV,AMES,IA 50011. RP Yatskar, A (reprint author), UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521, USA. RI Canfield, Paul/H-2698-2014 NR 35 TC 75 Z9 75 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1996 VL 54 IS 6 BP R3772 EP R3775 PG 4 WC Physics, Condensed Matter SC Physics GA VD677 UT WOS:A1996VD67700027 ER PT J AU Wilson, AN Timar, J SharpeySchafer, JF Crowell, B Carpenter, MP Janssens, RVF Blumenthal, DJ Ahmad, I Astier, A Azaiez, F Bergstrom, M Ducroux, L Gall, BJP Hannachi, F Khoo, TL Korichi, A Lauritsen, T LopezMartens, A Meyer, M Nisius, D Paul, ES Porquet, MG Redon, N Wilson, JN Nakatsukasa, T AF Wilson, AN Timar, J SharpeySchafer, JF Crowell, B Carpenter, MP Janssens, RVF Blumenthal, DJ Ahmad, I Astier, A Azaiez, F Bergstrom, M Ducroux, L Gall, BJP Hannachi, F Khoo, TL Korichi, A Lauritsen, T LopezMartens, A Meyer, M Nisius, D Paul, ES Porquet, MG Redon, N Wilson, JN Nakatsukasa, T TI Collective and quasiparticle excitations in superdeformed Hg-190 SO PHYSICAL REVIEW C LA English DT Article ID OCTUPOLE CORRELATIONS; EXCITED BANDS; EUROGAM ARRAY; NUCLEI; DY-152; SPIN; VIBRATION; DETECTOR; STATES; LINE AB Superdeformed (SD) States of Hg-190 have been studied with the Eurogam Phase 2 gamma-ray spectrometer using the Gd-160(S-34,4n) reaction. Two new excited SD bands have been found and identified as belonging to this nucleus, bringing the total number of SD bands in Hg-190 to 4. One of the new bands has a dynamic moment of inertia that is very similar to that of the yrast SD band of Hg-190 and most other SD bands in the A similar to 190 region. In contrast, the other band has a dynamic moment of inertia which is mainly constant as a function of rotational frequency and exhibits a dramatic increase at the lowest frequencies. The observed dynamic moments of inertia are compared with the results of random phase approximation calculations based on the cranked shell model. Finally, the known excited SD band has been extended towards lower frequencies and new transitions have been found linking this band to the yrast SD band. The extracted B(EI) values of the new linking transitions give further support for the possible octupole vibrational character of this band. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. INST PHYS NUCL,INST NATL PHYS NUCL & PHYS PARTICULES,CNRS,F-69622 VILLEURBANNE,FRANCE. INST NUCL PHYS,INST NATL PHYS NUCL & PHYS PARTICULES,CNRS,F-91405 ORSAY,FRANCE. CTR RECH NUCL,F-67037 STRASBOURGIMENT,FRANCE. CTR SPECTROMETRIE NUCL & SPECTROMETRIE MASSE,INST NATL PHYS NUCL & PHYS PARTICULES,CNRS,F-91406 ORSAY,FRANCE. AECL RES,CHALK RIVER LABS,CHALK RIVER,ON K0J 1J0,CANADA. RP Wilson, AN (reprint author), UNIV LIVERPOOL,OLIVER LODGE LAB,POB 147,LIVERPOOL L69 3BX,MERSEYSIDE,ENGLAND. RI Carpenter, Michael/E-4287-2015; Nakatsukasa, Takashi/O-9995-2014; OI Carpenter, Michael/0000-0002-3237-5734; Wilson, Anna/0000-0001-6928-1689 NR 25 TC 40 Z9 41 U1 0 U2 1 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 AUG PY 1996 VL 54 IS 2 BP 559 EP 567 DI 10.1103/PhysRevC.54.559 PG 9 WC Physics, Nuclear SC Physics GA VE860 UT WOS:A1996VE86000014 ER PT J AU Babu, BRS Zhu, SJ Ramayya, AV Hamilton, JH Peker, LK Wang, MG Ginter, TN Kormicki, J Ma, WC Cole, JD Aryaeinejad, R ButlerMoore, K Dardenne, YX Drigert, MW TerAkopian, GM Oganessian, YT Rasmussen, JO Asztalos, S Lee, LY Macchiavelli, AO Chu, SY Gregorich, KE Mohar, MF Prussin, S Stoyer, MA Lougheed, RW Moody, KJ Wild, JF AF Babu, BRS Zhu, SJ Ramayya, AV Hamilton, JH Peker, LK Wang, MG Ginter, TN Kormicki, J Ma, WC Cole, JD Aryaeinejad, R ButlerMoore, K Dardenne, YX Drigert, MW TerAkopian, GM Oganessian, YT Rasmussen, JO Asztalos, S Lee, LY Macchiavelli, AO Chu, SY Gregorich, KE Mohar, MF Prussin, S Stoyer, MA Lougheed, RW Moody, KJ Wild, JF TI Identification of gamma transitions in Ba-147, Ce-149, and Nd-151,Nd-153 SO PHYSICAL REVIEW C LA English DT Article ID SPIN AB The gamma transitions in Ba-147, Ce-149, and (ND)-N-151,153 have been identified from gamma-gamma-gamma, gamma-gamma, x-gamma, and x-gamma-gamma coincidence studies of spontaneous fission of Cf-252. The yrast positive parity band in Ce-149 is assigned to an i(13/2), neutron favored signature. The yrast negative parity band in Ce-149 is assigned a h(9/2) proton favored signature. The positive parity band in Nd-151 corresponds to the positive parity band in Ce-149. The negative parity band in Nd-153 corresponds to the negative parity bands of Ce-149 and Er-161. Th, band observed in Ba-147 is built on the h(9/2) orbital. The plots for J(1) in these isotopes are remarkably similar, supporting our assignments. C1 TSING HUA UNIV, DEPT PHYS, BEIJING 100084, PEOPLES R CHINA. JOINT INST HEAVY ION RES, OAK RIDGE, TN 37831 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. ORISE, OAK RIDGE, TN 37831 USA. MISSISSIPPI STATE UNIV, DEPT PHYS, MISSISSIPPI STATE, MS 39762 USA. IDAHO NATL ENGN LAB, IDAHO FALLS, ID 83415 USA. JOINT INST NUCL RES, DUBNA 141980, RUSSIA. LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. UNIV CALIF BERKELEY, DEPT NUCL ENGN, BERKELEY, CA 94720 USA. RP Babu, BRS (reprint author), VANDERBILT UNIV, DEPT PHYS, NASHVILLE, TN 37235 USA. NR 10 TC 17 Z9 18 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1996 VL 54 IS 2 BP 568 EP 571 DI 10.1103/PhysRevC.54.568 PG 4 WC Physics, Nuclear SC Physics GA VE860 UT WOS:A1996VE86000015 ER PT J AU Hauschild, K Wadsworth, R Clark, RM Hibbert, IM Fallon, P Macchiavelli, AO Fossan, DB Schnare, H Thorslund, I Nolan, PJ Semple, AT Walker, L AF Hauschild, K Wadsworth, R Clark, RM Hibbert, IM Fallon, P Macchiavelli, AO Fossan, DB Schnare, H Thorslund, I Nolan, PJ Semple, AT Walker, L TI Triaxial bands in Ce-133 SO PHYSICAL REVIEW C LA English DT Article ID ROTATIONAL BANDS; SUPERDEFORMED MINIMUM; NUCLEI; SHAPES AB An experiment performed on the early implementation of the GAMMASPHERE array to populate the high-spin states in Ce-133 has revealed the presence of several rotational structures with energy spacings of Delta E(gamma)similar to 100 keV. Some of these bands exhibit a backbend at (h) over bar omega similar to 0.6 MeV and are observed to high rotational frequencies-(h) over bar omega similar to 0.85 MeV. These characteristics are very different from those observed for any other rotational bands in this mass region. The properties of these new structures will be discussed within the framework of cranked Strutinsky-Woods-Saxon calculations. Currently, these bands are thought to be based on triaxial nuclear shapes. C1 UNIV YORK,DEPT PHYS,YORK YO1 5DD,N YORKSHIRE,ENGLAND. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. UNIV LIVERPOOL,OLIVER LODGE LAB,LIVERPOOL L69 3BX,MERSEYSIDE,ENGLAND. RI Hauschild, Karl/A-6726-2009 NR 21 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1996 VL 54 IS 2 BP 613 EP 619 DI 10.1103/PhysRevC.54.613 PG 7 WC Physics, Nuclear SC Physics GA VE860 UT WOS:A1996VE86000020 ER PT J AU Lazarev, YA Lobanov, YV Oganessian, YT Utyonkov, VK Abdullin, FS Polyakov, AN Rigol, J Shirokovsky, IV Tsyganov, YS Iliev, S Subbotin, VG Sukhov, AM Buklanov, GV Gikal, BN Kutner, VB Mezentsev, AN Subotic, K Wild, JF Longheed, RW Moody, KJ AF Lazarev, YA Lobanov, YV Oganessian, YT Utyonkov, VK Abdullin, FS Polyakov, AN Rigol, J Shirokovsky, IV Tsyganov, YS Iliev, S Subbotin, VG Sukhov, AM Buklanov, GV Gikal, BN Kutner, VB Mezentsev, AN Subotic, K Wild, JF Longheed, RW Moody, KJ TI alpha decay of (273)110: Shell closure at N=162 SO PHYSICAL REVIEW C LA English DT Article ID STABILITY; ELEMENTS; NUCLEI AB In bombardments of Pu-244 with S-34 we discovered the alpha-decaying nuclide (273)110. We conducted an extensive off-line search of the raw data for event sequences which fit the expected pattern of implantation in a position-sensitive detector and subsequent decay of (273)110 and its descendants. We observed one three-member sequence of genetically linked alpha decays, resulting in E(alpha)=11.35 MeV, a half-life of 0.3(-0.2)(+1.3) ms, and a production cross section of about 0.4 pb for (273)110. Other possible (273)110 event chains were also observed. The measured a-particle energy for the N=163 nuclide (273)110 provides direct evidence for a neutron shell closure at N=162. C1 JOINT INST NUCL RES, DUBNA 141980, RUSSIA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. INST NUCL SCI VINCA, YU-11001 BELGRADE, YUGOSLAVIA. NR 19 TC 151 Z9 152 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 EI 1089-490X J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1996 VL 54 IS 2 BP 620 EP 625 DI 10.1103/PhysRevC.54.620 PG 6 WC Physics, Nuclear SC Physics GA VE860 UT WOS:A1996VE86000021 ER PT J AU Forest, JL Pandharipande, VR Pieper, SC Wiringa, RB Schiavilla, R Arriaga, A AF Forest, JL Pandharipande, VR Pieper, SC Wiringa, RB Schiavilla, R Arriaga, A TI Femtometer toroidal structures in nuclei SO PHYSICAL REVIEW C LA English DT Article ID DEUTERON ELASTIC-SCATTERING; HIGH MOMENTUM-TRANSFER; MAGNETIC FORM-FACTOR; TENSOR POLARIZATION; ELECTRON-SCATTERING; EXCHANGE MODEL; CROSS-SECTION; LIGHT-NUCLEI; HE-3; CONFIGURATIONS AB The two-nucleon density distributions in states with isospin T=0, spin S=1, and projection M(S)=0 and +/- 1 are studied in H-2, He-3,He-4, Li-6,Li-7, and O-16. The equidensity surfaces for M(S)=0 distributions are found to be toroidal in shape, while those of M(S)=+/-1 have dumbbell shapes at large density. The dumbbell shapes are generated by rotating tori. The toroidal shapes indicate that the tensor.correlations have near maximal strength at r<2 fm in all these nuclei:. They provide new insights and simple explanations of the structure and electromagnetic form factors of the deuteron, the quasideuteron model, and the dp, nd, and alpha d L=2 (D-wave) components in He-3, He-4, and Li-6. The toroidal distribution has a maximum-density diameter of similar to 1 fm and a half-maximum density thickness of similar to 0.9 fm. Many realistic models of nuclear forces predict these values, which are supported by the observed electromagnetic form factors of the deuteron, and also predicted by classical Skyrme effective Lagrangians, related to QCD in the limit of infinite colors. Due to the rather small size of this structure, it could have a revealing relation to certain aspects of QCD. Experiments to probe this structure and its effects in nuclei are suggested. Pair distribution functions in other T,S channels are also discussed; those in T,S= 1,1 have anisotropies expected from one-pion-exchange interactions. The tensor correlations in T,S=0,1 states are found to deplete the number of T,S=1,0 pairs in nuclei and cause a reduction in nuclear binding energies via many-body effects. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. CONTINUOUS ELECTRON BEAM ACCELERATOR FACIL CTR,THEORY GRP,NEWPORT NEWS,VA 23606. OLD DOMINION UNIV,DEPT PHYS,NORFOLK,VA 23529. UNIV LISBON,CTR FIS NUCL,P-1699 LISBON,PORTUGAL. RP Forest, JL (reprint author), UNIV ILLINOIS,DEPT PHYS,1110 W GREEN ST,URBANA,IL 61801, USA. RI Wiringa, Robert/M-4970-2015; Arriaga, Ana/N-2369-2015 OI Arriaga, Ana/0000-0002-8113-7425 NR 57 TC 134 Z9 134 U1 0 U2 4 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 AUG PY 1996 VL 54 IS 2 BP 646 EP 667 DI 10.1103/PhysRevC.54.646 PG 22 WC Physics, Nuclear SC Physics GA VE860 UT WOS:A1996VE86000024 ER PT J AU Chapman, S Nix, JR AF Chapman, S Nix, JR TI Realistic expanding source model for invariant one-particle multiplicity distributions and two-particle correlations in relativistic heavy-ion collisions SO PHYSICAL REVIEW C LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; BOSE-EINSTEIN CORRELATIONS; HIGH-ENERGY COLLISIONS; PION INTERFEROMETRY; RESONANCE DECAYS; CROSS TERM; EXPANSION; RADII AB We present a realistic expanding source model with nine parameters that are necessary and sufficient to describe the main physics occurring during hydrodynamical freeze-out of the excited hadronic matter produced in relativistic heavy-ion collisions. As a first test of the model, we compare it to data from central Si + Au collisions at p(lab)/A=14.6 GeV/c measured in experiment E-802 at the Brookhaven Alternating Gradient Synchrotron. An overall chi(2) per degree of freedom of 1.055 is achieved for a fit to 1416 data points involving invariant pi(+), pi(-), K+, and K- one-particle multiplicity distributions and pi(+) and K+ two-particle correlations. The 99%-confidence region of parameter space is identified, leading to one-dimensional error estimates on the nine fitted parameters and other calculated physical quantities. Three of the most important results are the freeze-out temperature, longitudinal proper time, and baryon density along the symmetry axis. For these we find values of 92.9 +/- 4.4 MeV, 8.2 +/- 2.2 fm/c, and 0.0222(-0.0069)(+0.0096) fm(-3), respectively. RP Chapman, S (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 37 TC 29 Z9 29 U1 0 U2 1 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 AUG PY 1996 VL 54 IS 2 BP 866 EP 881 DI 10.1103/PhysRevC.54.866 PG 16 WC Physics, Nuclear SC Physics GA VE860 UT WOS:A1996VE86000049 ER PT J AU Urban, W Phillips, WR Durell, JL Jones, MA Leddy, M Pearson, CJ Smith, AG Varley, BJ Ahmad, I Morss, LR Bentaleb, M Lubkiewicz, E Schulz, N AF Urban, W Phillips, WR Durell, JL Jones, MA Leddy, M Pearson, CJ Smith, AG Varley, BJ Ahmad, I Morss, LR Bentaleb, M Lubkiewicz, E Schulz, N TI Octupole correlations in neutron rich, odd-A lanthanum nuclei SO PHYSICAL REVIEW C LA English DT Article ID DEFORMATION; FISSION; REGION; BANDS AB Neutron-rich, odd-Z nuclei La-145 and La-147 populated in spontaneous fission of Cm-248 were studied using the EUROGAM array. The experiment indicates the presence of similar octupole correlations in the studied La isotopes as found in the barium core nuclei. Alternating-parity structures were found in La-145, indicating enhanced octupole correlations, as observed in Ba-144, while in La-147 octupole effects are weakened by alignment phenomena, as seen in the core nucleus Ba-146. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV LOUIS PASTEUR STRASBOURG 1,IN2P3 CNRS,CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. RP Urban, W (reprint author), UNIV MANCHESTER,DEPT PHYS & ASTRON,MANCHESTER M13 9PL,LANCS,ENGLAND. NR 17 TC 31 Z9 33 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 AUG PY 1996 VL 54 IS 2 BP 945 EP 948 DI 10.1103/PhysRevC.54.945 PG 4 WC Physics, Nuclear SC Physics GA VE860 UT WOS:A1996VE86000057 ER PT J AU Batchelder, JC Toth, KS Zganjar, EF Moltz, DM Bingham, CR Ognibene, TJ Powell, J Rowe, MW AF Batchelder, JC Toth, KS Zganjar, EF Moltz, DM Bingham, CR Ognibene, TJ Powell, J Rowe, MW TI Determination of the Po-190 alpha reduced width SO PHYSICAL REVIEW C LA English DT Article ID DECAY; ISOTOPES; STATE AB The isotope Po-190 was produced in the Sm-144(Ti-48,2n) reaction and its alpha-decay energy and half-life were measured to be 7.49(4) MeV and 2.0(-1.0)(+0.5) ms, respectively. These data compare as follows with preliminary values reported by Quint et al.: E(alpha) = 7482(20) keV and a T-1/2 = 9.6(-4.4)(+47) ms. While the two energies agree, the half-lives differ by a factor of almost 5. The earlier data yield an ct reduced width which is much smaller than those of neighboring nuclides; our Po-190 energy and half-life result in a width that fits the overall alpha-decay-rate systematics in the mass region above the Z = 82 closed shell. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,BERKELEY,CA 94720. UNIV TENNESSEE,KNOXVILLE,TN 37996. RP Batchelder, JC (reprint author), LOUISIANA STATE UNIV,BATON ROUGE,LA 70803, USA. NR 13 TC 7 Z9 7 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 AUG PY 1996 VL 54 IS 2 BP 949 EP 951 DI 10.1103/PhysRevC.54.949 PG 3 WC Physics, Nuclear SC Physics GA VE860 UT WOS:A1996VE86000058 ER PT J AU Bailey, B Berger, EL Gordon, LE AF Bailey, B Berger, EL Gordon, LE TI Production of a prompt photon in association with a charm quark at next-to-leading order in QCD SO PHYSICAL REVIEW D LA English DT Article ID ALPHA-S CALCULATION; P(P)OVER-BAR COLLIDERS AB A second order O(alpha(s)(2)) calculation in perturbative quantum chromodynamics of the two particle inclusive cross section is presented for the reaction p + (p) over bar --> gamma+ c + X for large values of the transverse momentum of the prompt photon and charm quark. The combination of analytic and Monte Carlo integration methods used here to perform phase-space integrations facilitates the imposition of photon isolation restrictions and other selections of relevance in experiments. Differential distributions are provided for various observables. Positive correlations in rapidity are predicted. C1 ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439. RP Bailey, B (reprint author), ECKERD COLL,DEPT PHYS,ST PETERSBURG,FL 33711, USA. NR 23 TC 20 Z9 20 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 AUG 1 PY 1996 VL 54 IS 3 BP 1896 EP 1907 DI 10.1103/PhysRevD.54.1896 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VA662 UT WOS:A1996VA66200006 ER PT J AU Beneke, M Rothstein, IZ AF Beneke, M Rothstein, IZ TI Hadroproduction of quarkonium in fixed-target experiments SO PHYSICAL REVIEW D LA English DT Article ID QCD ANALYSIS; J/PSI; FRAGMENTATION; CHARMONIUM; COLLISIONS; TEVATRON; GEV/C; DECAY; PSI' AB We analyze charmonium and bottomonium production at fixed-target experiments. We find that the inclusion of color octet production channels removes large discrepancies between experiment and the predictions of the color singlet model for the total production cross section. Furthermore, including octet contributions accounts for the observed direct to total J/psi production ratio. As found earlier for photoproduction of quarkonia, a fit to fixed-target data requires smaller color octet matrix elements than those extracted from high-p(t) production at the Fermilab Tevatron. We argue that this difference can be explained by systematic differences in the velocity expansion for collider and fixed-target predictions. While the color octet mechanism thus appears to be an essential part of a satisfactory description of fixed-target data important discrepancies remain for the chi(c1)/chi(c2) production ratio and J/psi (psi') polarization. These discrepancies, as well as the differences between pion- and proton-induced collisions, emphasize the need for including higher twist effects in addition to the color octet mechanism. C1 UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. RP Beneke, M (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 31 TC 125 Z9 128 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 AUG 1 PY 1996 VL 54 IS 3 BP 2005 EP 2016 DI 10.1103/PhysRevD.54.2005 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VA662 UT WOS:A1996VA66200014 ER PT J AU Worah, MP AF Worah, MP TI New supersymmetric CP-violating contribution to neutral meson mixing SO PHYSICAL REVIEW D LA English DT Article ID STANDARD MODEL; B-DECAYS; ASYMMETRIES; MATRIX AB We study the contribution to flavor-changing neutral current processes from box diagrams with light Higgsinos and squarks. Starting with just the Cabibbo-Kobayashi-Maskawa (CKM) phase, we find contributions to the K-0 and B-0 meson mass matrices that are out of phase with the standard model contributions in the case of substantial mixing between the up-type squarks. This difference in phase could be large enough to be detected at the proposed B factories, with interesting implications for the unitarity triangle of CKM matrix elements. RP Worah, MP (reprint author), STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 21 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 1996 VL 54 IS 3 BP 2198 EP 2203 DI 10.1103/PhysRevD.54.2198 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VA662 UT WOS:A1996VA66200035 ER PT J AU Lampert, MA Dawson, JF Cooper, F AF Lampert, MA Dawson, JF Cooper, F TI Time evolution of the chiral phase transition during a spherical expansion SO PHYSICAL REVIEW D LA English DT Article ID ENERGY-MOMENTUM TENSOR; QUANTUM-FIELD-THEORY; LARGE-N; COLLISIONS; CONDENSATE; DOMAINS; MODELS AB We examine the nonequilibrium time evolution of the hadronic plasma produced in a relativistic heavy ion collision, assuming a spherical expansion into the vacuum. We study the 0(4) linear sigma model to leading order in a large-N expansion. Starting at a temperature above the phase transition, the system expands and cools, finally settling into the broken symmetry vacuum state. We consider the proper time evolution of the effective pion mass, the order parameter [sigma], and the particle number distribution. We examine several different initial conditions and look for instabilities (exponentially growing long wavelength modes) which can lead to the formation of disoriented chiral condensates (DCC's). We find that instabilities exist for proper times which are less than 3 fm/c. We also show that an experimental signature of domain growth is an increase in the low momentum spectrum of outgoing pions when compared to an expansion in thermal equilibrium. In comparison to particle production during a longitudinal expansion, we find that in a spherical expansion the system reaches the ''out'' regime much faster and more particles get produced. However the size of the unstable region, which is related to the domain size of DCC's, is not enhanced. C1 LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. RP UNIV NEW HAMPSHIRE, DEPT PHYS, DURHAM, NH 03824 USA. NR 29 TC 69 Z9 69 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 AUG 1 PY 1996 VL 54 IS 3 BP 2213 EP 2221 DI 10.1103/PhysRevD.54.2213 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VA662 UT WOS:A1996VA66200037 ER PT J AU ArkaniHamed, N Cheng, HC Hall, LJ AF ArkaniHamed, N Cheng, HC Hall, LJ TI Supersymmetric theory of flavor with radiative fermion masses SO PHYSICAL REVIEW D LA English DT Article ID SYMMETRY-BREAKING; QUARK MASS; UNIFICATION; DECAY; SUPERGRAVITY; MATRIX; MODELS; SEARCH; SO(10); SU(5) AB Supersymmetric theories involving a spontaneously broken flavor symmetry can lead to fermion masses which vanish at the tree level but are generated by radiative corrections. In the context of supersymmetric theories with minimal low energy field content we discuss which fermion masses and mixings may be obtained radiatively, and find that constraints from flavor-changing phenomenology imply that only the first generation fermion masses and some (but not all) CKM mixings can naturally come from radiative corrections. We also consider general conditions on theories of flavor which guarantee the existence of tree-level massless fermions while having nontrivial CKM matrix elements at the tree level. Two complete models of flavor are presented. In the first model, all first generation fermion masses are radiatively generated. In the second model, the electron and up quark mass are due to radiative corrections whereas the down mass appears at the tree level, as does a successful prediction for the Cabibbo angle sin theta(c)=root m(d)/m(s). C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP ArkaniHamed, N (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. NR 35 TC 31 Z9 31 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 AUG 1 PY 1996 VL 54 IS 3 BP 2242 EP 2260 DI 10.1103/PhysRevD.54.2242 PG 19 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VA662 UT WOS:A1996VA66200040 ER PT J AU Berger, EL Gordon, LE AF Berger, EL Gordon, LE TI Analytic calculation of prompt photon plus associated heavy flavor at next-to-leading order in QCD SO PHYSICAL REVIEW D LA English DT Article ID DIFFERENTIAL CROSS-SECTION; HADRON-COLLISIONS; QUARK PRODUCTION; P(P)OVER-BAR COLLIDERS; COMPTON-SCATTERING; CHARM; DISTRIBUTIONS; SINGLE; PROTON AB Contributions through second order, O(alpha(s)(2)), in perturbative quantum chromodynamics are calculated analytically for inclusive associated production of a prompt photon and a charm quark at large values of transverse momentum in high energy hadron-hadron collisions. Seven partonic subprocesses contribute at order alpha(s)(2). We find important corrections to the lowest order, O(alpha(s)), subprocess cg-->gamma c. We demonstrate to what extent data from p+(p) over bar-->gamma+c+X may serve to measure the charm quark density in the nucleon. RP Berger, EL (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. NR 40 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 1996 VL 54 IS 3 BP 2279 EP 2294 DI 10.1103/PhysRevD.54.2279 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VA662 UT WOS:A1996VA66200043 ER PT J AU Lombardo, MP Kogut, JB Sinclair, DK AF Lombardo, MP Kogut, JB Sinclair, DK TI Pathologies of quenched lattice QCD at nonzero density and its effective potential SO PHYSICAL REVIEW D LA English DT Article ID FINITE-DENSITY; SIMULATIONS; TEMPERATURE; SPECTRUM; FERMIONS AB We simulate lattice QCD at nonzero baryon density and zero temperature in the quenched approximation, both in the scaling region and in the infinite coupling limit. We investigate the nature of the forbidden region - the range of chemical potential where the simulations grow prohibitively expensive, and the results, when available, are puzzling if not unphysical. At weak coupling we explore the sensitivity of these pathologies to the lattice size, and find that using a large lattice (64X16(3)) does not remove them. The effective potential sheds considerable light on the problems in the simulations, and gives a clear interpretation of the forbidden region. The strong coupling simulations are particularly illuminating on this point. C1 DESY, D-22603 HAMBURG, GERMANY. UNIV ILLINOIS, DEPT PHYS, URBANA, IL 61801 USA. ARGONNE NATL LAB, HEP DIV, ARGONNE, IL 60439 USA. RP FORSCHUNGSZENTRUM JULICH, HLRZ, POSTFACH 1913, D-52425 JULICH, GERMANY. NR 23 TC 33 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 AUG 1 PY 1996 VL 54 IS 3 BP 2303 EP 2316 DI 10.1103/PhysRevD.54.2303 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VA662 UT WOS:A1996VA66200045 ER PT J AU Carone, CD Hall, LJ Murayama, H AF Carone, CD Hall, LJ Murayama, H TI Supersymmetric theory of flavor and R parity SO PHYSICAL REVIEW D LA English DT Article ID DISCRETE GAUGE-SYMMETRY; MASS MATRIX MODELS; PROTON DECAY; STANDARD MODEL; BARYON NUMBER; HORIZONTAL SYMMETRIES; BROKEN SUPERSYMMETRY; UNIFIED THEORIES; FERMION MASSES; LEPTON NUMBER AB We construct a renormalizable, supersymmetric theory of flavor and R parity based on the discrete flavor group (S-3)(3). The model can account for all the masses and mixing angles of the standard model, while maintaining sufficient squark degeneracy to circumvent the supersymmetric flavor problem. By starting with a simpler set of flavor symmetry-breaking fields than we have suggested previously, we construct an economical Froggatt-Nielsen sector that generates the desired elements of the fermion Yukawa matrices. With the particle content above the flavor scale completely specified, we show that all renormalizable R-parity-violating interactions involving the ordinary matter fields are forbidden by the flavor symmetry. Thus, R parity arises as an accidental symmetry in our model. Planck-suppressed operators that violate R parity, if present, can be rendered harmless by taking the flavor scale to be less than or similar to 8x10(10) GeV. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Carone, CD (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. RI Murayama, Hitoshi/A-4286-2011 NR 64 TC 31 Z9 31 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 AUG 1 PY 1996 VL 54 IS 3 BP 2328 EP 2339 DI 10.1103/PhysRevD.54.2328 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VA662 UT WOS:A1996VA66200047 ER PT J AU Boettcher, S Paczuski, M AF Boettcher, S Paczuski, M TI Ultrametricity and memory in a solvable model of self-organized criticality SO PHYSICAL REVIEW E LA English DT Article ID PUNCTUATED-EQUILIBRIUM; 1/F NOISE; BIOLOGICAL EVOLUTION; INVASION PERCOLATION; FIELD-THEORY; EARTHQUAKES; DYNAMICS; AVALANCHES; GROWTH AB Slowly driven dissipative systems may evolve to a critical state where long periods of apparent equilibrium are punctuated by intermittent avalanches of activity. We present a self-organized critical model of punctuated equilibrium behavior in the context of biological evolution, and solve it in the limit that the number of independent traits for each species diverges. We derive an exact equation of motion for the avalanche dynamics from the microscopic rules. In the continuum Limit, avalanches propagate via a diffusion equation with a nonlocal, history dependent potential representing memory. This nonlocal potential gives rise to a non-Gaussian (fat) tail for the subdiffusive spreading of activity. The probability for the activity to spread beyond a distance r in time s decays as root(24/pi)s(-3/2)x(1/3)exp[-3/4x(1/3)] for the x=r(4)/s much greater than 1. The potential represents a hierarchy of time scales that is dynamically generated by the ultrametric structure of avalanches, which can be quantified in terms of ''backward'' avalanches. In addition, a number of other correlation functions characterizing the punctuated equilibrium dynamics are determined exactly. C1 UNIV OKLAHOMA,DEPT PHYS & ASTRON,NORMAN,OK 73019. RP Boettcher, S (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Boettcher, Stefan/G-2640-2010 OI Boettcher, Stefan/0000-0003-1273-6771 NR 45 TC 25 Z9 25 U1 2 U2 7 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 AUG PY 1996 VL 54 IS 2 BP 1082 EP 1095 DI 10.1103/PhysRevE.54.1082 PG 14 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VD674 UT WOS:A1996VD67400020 ER PT J AU Stahl, K Artioli, G Hanson, JC AF Stahl, K Artioli, G Hanson, JC TI The dehydration process in the zeolite laumontite: A real-time synchrotron X-ray powder diffraction study SO PHYSICS AND CHEMISTRY OF MINERALS LA English DT Article AB The dehydration process of the natural zeolite laumontite Ca4Si16Al8O48. 18 H2O has been studied in situ by means of powder diffraction and X-ray synchrotron radiation. Powder diffraction profiles suitable for Rietveld refinements were accumulated in time intervals of 5 minutes using a position sensitive detector (CPS-120 by INEL), while the temperature increased in steps of about 5 K. The synchronization of accumulation time and temperature plateau allowed collection of 62 temperature-resolved powder patterns in the range 310-584 K, whose analysis produced a dynamic picture of the laumontite structure response to dehydration. The first zeolitic water molecules diffusing out of the channels are those not bonded to the Ca cations and located in the W(1) site, whose occupancy drops smoothly to 10% during heating to 349 K, while the sample in the capillary is still submerged in water. The remaining W(1) and 60% of W(5) water molecules are expelled rather sharply at about 370 K. At this temperature all remaining water submerging the powder crystallites is lost, the structure contains about 13 water molecules/cell, and the crystal structure is that of leonhardite. On continued heating 80% of the water molecules from the W (2) site are lost between 420 and 480 K, while a small amount of the diffusing water is reinserted in the W(5) site. The occupancy factor of the W(8) site decreases starting at 480 K, and reaches a maximum loss of 20% at 584 K. The combined occupancy of the Ca-coordinated W(2) and W(8) water sites never falls much below two, so that the Ca cations in the channels, which are bonded to four framework oxygen atoms, are nearly six-coordinated in the explored temperature range. The water loss is accompanied by large changes in the unit cell dimensions. Except at 367 K, where the excess surrounding water is leaving, all changes in cell. dimensions are gradual. The loss of the hydrogen bonded W(1) and W(5) water molecules is related to most of the unit cell volume reduction below 370 K, as shown by the contraction of the a-, b- and c-axes and the increase in the monoclinic angle. Loss of the Ca-coordinated W(2) and W(8) water molecules has a small effect on the unit cell volume as the continued contraction of the a- and c-axes is counter-balanced by a large expansion in the b-axis and a decrease in the monoclinic beta angle. C1 LUND UNIV,S-22100 LUND,SWEDEN. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Hanson, jonathan/E-3517-2010; Artioli, Gilberto/F-2149-2015; OI Artioli, Gilberto/0000-0002-8693-7392; Stahl, Kenny/0000-0002-4459-3026 NR 14 TC 35 Z9 35 U1 2 U2 10 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0342-1791 J9 PHYS CHEM MINER JI Phys. Chem. Miner. PD AUG PY 1996 VL 23 IS 6 BP 328 EP 336 PG 9 WC Materials Science, Multidisciplinary; Mineralogy SC Materials Science; Mineralogy GA VD850 UT WOS:A1996VD85000002 ER PT J AU Burakovsky, L AF Burakovsky, L TI First order quark-gluon/hadron transition may affect cosmological nucleosynthesis SO PHYSICS LETTERS B LA English DT Article DE nucleosynthesis; nucleation; inhomogeneities; surface tension; quark-gluon/hadron transition ID HADRON PHASE-TRANSITION; QCD SUM-RULES; PRIMORDIAL NUCLEOSYNTHESIS; EARLY UNIVERSE; FINITE-TEMPERATURE; INTERFACE TENSION; SURFACE-TENSION; QUANTUM CHROMODYNAMICS; RESONANCE PHYSICS; STRANGE MATTER AB In a model of a first order quark-gluon/hadron phase transition in which the hadronic phase is considered as vacuum bubbles growing in the quark-gluon background with chiral symmetry broken inside the bubble, we find the estimate for the length scale associated with inhomogeneities originated during the transition, 10 m less than or similar to l less than or similar to 40 m, being sufficient to produce significant effects on cosmological nucleosynthesis. RP Burakovsky, L (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,T-8,LOS ALAMOS,NM 87545, USA. NR 61 TC 4 Z9 4 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 1 PY 1996 VL 382 IS 1-2 BP 13 EP 18 DI 10.1016/0370-2693(96)00517-5 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA UY758 UT WOS:A1996UY75800003 ER PT J AU Michael, R Barakat, MB Bart, S Chrien, RE Clark, BC Ernst, DJ Hama, S Hicks, KH Hinton, W Hungerford, EV Jiang, MF Kishimoto, T Kormanyos, CM Kurth, LJ Lee, L Mayes, B Peterson, RJ Pinsky, L Sawafta, R Sutter, R Tang, L Wise, JE AF Michael, R Barakat, MB Bart, S Chrien, RE Clark, BC Ernst, DJ Hama, S Hicks, KH Hinton, W Hungerford, EV Jiang, MF Kishimoto, T Kormanyos, CM Kurth, LJ Lee, L Mayes, B Peterson, RJ Pinsky, L Sawafta, R Sutter, R Tang, L Wise, JE TI K+ elastic scattering from C and Li-6 at 715 MeV/c SO PHYSICS LETTERS B LA English DT Article ID TOTAL CROSS-SECTIONS; NUCLEUS SCATTERING; IMPULSE APPROXIMATION; KAONS AB Elastic differential cross sections for K+ mesons scattered from C-nat and Li-6 targets have been measured at an incident momentum of 715 MeV/c and at angles of 7 degrees to 42 degrees in the laboratory frame. The experimental cross sections agree, within errors, with two different parameter-free impulse approximation calculations. To reduce the effects of the systematic errors, the ratio of the experimental cross sections for C-nat to Li-6 is compared to the theoretical values, and these ratios do not agree with theory. This discrepancy suggests either a density-dependent alteration of K+-nucleon amplitudes or a failure of the optical potential calculations to describe these nuclides adequately. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. HAMPTON UNIV,HAMPTON,VA 23668. HIROSHIMA UNIV ECON,HIROSHIMA 73101,JAPAN. OSAKA UNIV,TOYONAKA,OSAKA 560,JAPAN. OHIO STATE UNIV,COLUMBUS,OH 43210. TRIUMF,VANCOUVER,BC V6T 2A3,CANADA. UNIV COLORADO,BOULDER,CO 80309. UNIV HOUSTON,HOUSTON,TX 77204. VANDERBILT UNIV,NASHVILLE,TN 37235. RP Michael, R (reprint author), OHIO UNIV,ATHENS,OH 45701, USA. NR 30 TC 34 Z9 36 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 1 PY 1996 VL 382 IS 1-2 BP 29 EP 34 DI 10.1016/0370-2693(96)00664-8 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA UY758 UT WOS:A1996UY75800006 ER PT J AU Ahmad, S Bonner, BE Chan, CS Clement, JM Efremov, SV Efstathiadis, E Eiseman, SE Etkin, A Foley, KJ Hackenburg, RW Kramer, MA Lindenbaum, SJ Longacre, RS Love, WA Marx, J Mutchler, GS Platner, ED Saulys, AC Schroeder, LS Themann, HW Zhao, K Zhu, Y AF Ahmad, S Bonner, BE Chan, CS Clement, JM Efremov, SV Efstathiadis, E Eiseman, SE Etkin, A Foley, KJ Hackenburg, RW Kramer, MA Lindenbaum, SJ Longacre, RS Love, WA Marx, J Mutchler, GS Platner, ED Saulys, AC Schroeder, LS Themann, HW Zhao, K Zhu, Y TI Lambda production by 11.6 Alpha GeV/c Au beam on Au target SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEUS COLLISIONS; STRANGE AB We present the first measurement at AGS energies of the rapidity and transverse mass distributions for Lambda production with Au beam on Au target. The measurements cover the rapidity region of 2.0-3.2 and transverse momenta of 0.0-1.4 GeV/c. The results are compared with the predictions of two models. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. CUNY CITY COLL,NEW YORK,NY 10031. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Ahmad, S (reprint author), RICE UNIV,HOUSTON,TX 77251, USA. NR 13 TC 56 Z9 56 U1 0 U2 2 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 1 PY 1996 VL 382 IS 1-2 BP 35 EP 39 DI 10.1016/0370-2693(96)00642-9 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA UY758 UT WOS:A1996UY75800007 ER PT J AU Burrows, PN Masuda, H Muller, D Ohnishi, Y AF Burrows, PN Masuda, H Muller, D Ohnishi, Y TI Application of ''optimised'' perturbation theory to determination of alpha(s)(M(Z)(2)) from hadronic event shape observables in e(+)e(-) annihilation SO PHYSICS LETTERS B LA English DT Article ID ELECTRON-POSITRON ANNIHILATION; JET PRODUCTION-RATES; CONSTANT ALPHA-S; QUANTUM CHROMODYNAMICS; E+E-ANNIHILATION; ENERGY CORRELATIONS; Z0 RESONANCE; CROSS-SECTIONS; LEADING ORDER; Z-DECAYS AB We have applied so-called ''optimised'' perturbation theory to resolve the renormalisation-scale (mu) ambiguity of exact O(alpha(s)(2)) QCD calculations of event shape observables in e(+)e(-) --> hadrons. We fitted the optimised predictions for 15 observables to hadronic Z(0) decay data from the SLD experiment to determine alpha(s)(M(Z)(2)). Comparing with results using the physical scale mu = M(Z) we found no reduction in the scatter among alpha(s)(M(Z)(2)) values from the 15 observables, implying that the O(alpha(s)(2)) predictions with optimised scales are numerically no closer to the exact all-orders results than those with the physical scale. C1 STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. NAGOYA UNIV, NAGOYA, AICHI 464, JAPAN. RP MIT, 77 MASSACHUSETTS AVE, CAMBRIDGE, MA 02139 USA. NR 56 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD AUG 1 PY 1996 VL 382 IS 1-2 BP 157 EP 164 DI 10.1016/0370-2693(96)00570-9 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA UY758 UT WOS:A1996UY75800025 ER PT J AU Ambrogiani, M Armstrong, TA Bettoni, D Bharadwaj, V Biino, C Borreani, G Broemmelsiek, D Buzzo, A Calabrese, R Ceccucci, A Cester, R Church, M Dalpiaz, P Dalpiaz, PF Dibenedetto, R Dimitroyannis, D Fabbri, M Fast, J Gianoli, A Ginsburg, CM Gollwitzer, K Hahn, A Hasan, MA Hsueh, S Lewis, R Luppi, E Macri, M Majewska, AM Mandelkern, M Marchetto, F Marinelli, M Marques, J Marsh, W Martini, M Masuzawa, M Menichetti, E Migliori, A Mussa, R Palestini, S Pallavicini, M Pastrone, N Patrignani, C Peoples, J Pesando, L Petrucci, F Pia, MG Pordes, S Rapidis, PA Ray, R Reid, J Rinaudo, G Roccuzzo, B Rosen, J Santroni, A Sarmiento, M Savrie, M Scalisi, A Schultz, J Seth, KK Smith, A Smith, GA Sozzi, M Trokenheim, S Weber, MF Werkema, S Zhang, Y Zhao, J Zioulas, G AF Ambrogiani, M Armstrong, TA Bettoni, D Bharadwaj, V Biino, C Borreani, G Broemmelsiek, D Buzzo, A Calabrese, R Ceccucci, A Cester, R Church, M Dalpiaz, P Dalpiaz, PF Dibenedetto, R Dimitroyannis, D Fabbri, M Fast, J Gianoli, A Ginsburg, CM Gollwitzer, K Hahn, A Hasan, MA Hsueh, S Lewis, R Luppi, E Macri, M Majewska, AM Mandelkern, M Marchetto, F Marinelli, M Marques, J Marsh, W Martini, M Masuzawa, M Menichetti, E Migliori, A Mussa, R Palestini, S Pallavicini, M Pastrone, N Patrignani, C Peoples, J Pesando, L Petrucci, F Pia, MG Pordes, S Rapidis, PA Ray, R Reid, J Rinaudo, G Roccuzzo, B Rosen, J Santroni, A Sarmiento, M Savrie, M Scalisi, A Schultz, J Seth, KK Smith, A Smith, GA Sozzi, M Trokenheim, S Weber, MF Werkema, S Zhang, Y Zhao, J Zioulas, G TI Light-quark meson spectroscopy SO PHYSICS OF ATOMIC NUCLEI LA English DT Article; Proceedings Paper CT 3rd International Conference on Nucleon-Antinucleon Physics CY SEP 11-16, 1995 CL INST THEORET & EXPTL PHYS, MOSCOW, RUSSIA SP Russian Acad Sci, Dept Nucl Phys, Russian Fdn Basic Res, Inst Theoret & Exptl Phys, Int Sci Fdn, INFN, Lab Nazl Frascati, Italy HO INST THEORET & EXPTL PHYS ID CALORIMETER AB In-flight data for proton-antiproton annihilation to 3 pi(0) and pi(0)2 eta in E760 experiment at Fermilab are presented. Data show resonance structures in the 1500 and 2000 MeV/c regions, where glueball states are predicted. A phenomenological amplitude analysis is ongoing. C1 UNIV FERRARA,I-44100 FERRARA,ITALY. PENN STATE UNIV,UNIVERSITY PK,PA 16802. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IST NAZL FIS NUCL,I-10125 TURIN,ITALY. UNIV TURIN,I-10125 TURIN,ITALY. UNIV CALIF IRVINE,IRVINE,CA 92717. IST NAZL FIS NUCL,I-16146 GENOA,ITALY. UNIV GENOA,I-16146 GENOA,ITALY. NORTHWESTERN UNIV,EVANSTON,IL 60208. PENN STATE UNIV,YORK,PA 17403. RP Ambrogiani, M (reprint author), IST NAZL FIS NUCL,I-44100 FERRARA,ITALY. RI Pia, Maria Grazia/C-7034-2012; Sozzi, Marco/H-1674-2011; Luppi, Eleonora/A-4902-2015; Calabrese, Roberto/G-4405-2015; Pallavicini, Marco/G-5500-2012; Gianoli, Alberto/H-5544-2015; Patrignani, Claudia/C-5223-2009 OI Pia, Maria Grazia/0000-0002-3579-9639; Mussa, Roberto/0000-0002-0294-9071; Sozzi, Marco/0000-0002-2923-1465; Luppi, Eleonora/0000-0002-1072-5633; Calabrese, Roberto/0000-0002-1354-5400; Pallavicini, Marco/0000-0001-7309-3023; Gianoli, Alberto/0000-0002-2456-8667; Patrignani, Claudia/0000-0002-5882-1747 NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD AUG PY 1996 VL 59 IS 8 BP 1307 EP 1311 PG 5 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA VG182 UT WOS:A1996VG18200005 ER PT J AU Amsler, C Armstrong, DS Baker, CA Barnett, BM Batty, CJ Benayoun, M Beuchert, K Birien, P Blum, P Bossingham, R Braune, K Brose, J Bugg, DV Case, T Cooper, A Cramer, O Crowe, KM Degener, T Dietz, HP Djaoshvili, N vonDombrowski, S Doser, M Dunnweber, W Engelhardt, D Englert, M Faessler, MA Giarritta, P Hackmann, R Haddock, RP Heinsius, FH Herz, M Hessey, NP Hidas, P Holzhaussen, C Illinger, P Jamnik, D Kalinowsky, H Kalteyer, B Kammle, B Kiel, T Kisiel, J Klempt, E Koch, H Kolo, C Kunze, M Lakata, M Landua, R Ludemann, J Matthay, J McCrady, R Merlo, JP Meyer, CA Montanet, L Noble, A Ouared, R OuldSaada, F Peters, K Pinder, CN Pinder, G Ravndal, S Regenfus, C Schafer, E Schmidt, P Schutrumpf, M Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Urner, D Volcker, C Walter, F Walther, D Wiedner, U Winter, N Zoll, J Zou, BS Zupancic, C AF Amsler, C Armstrong, DS Baker, CA Barnett, BM Batty, CJ Benayoun, M Beuchert, K Birien, P Blum, P Bossingham, R Braune, K Brose, J Bugg, DV Case, T Cooper, A Cramer, O Crowe, KM Degener, T Dietz, HP Djaoshvili, N vonDombrowski, S Doser, M Dunnweber, W Engelhardt, D Englert, M Faessler, MA Giarritta, P Hackmann, R Haddock, RP Heinsius, FH Herz, M Hessey, NP Hidas, P Holzhaussen, C Illinger, P Jamnik, D Kalinowsky, H Kalteyer, B Kammle, B Kiel, T Kisiel, J Klempt, E Koch, H Kolo, C Kunze, M Lakata, M Landua, R Ludemann, J Matthay, J McCrady, R Merlo, JP Meyer, CA Montanet, L Noble, A Ouared, R OuldSaada, F Peters, K Pinder, CN Pinder, G Ravndal, S Regenfus, C Schafer, E Schmidt, P Schutrumpf, M Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Urner, D Volcker, C Walter, F Walther, D Wiedner, U Winter, N Zoll, J Zou, BS Zupancic, C TI Antiproton annihilation at rest in liquid deuterium SO PHYSICS OF ATOMIC NUCLEI LA English DT Article; Proceedings Paper CT 3rd International Conference on Nucleon-Antinucleon Physics CY SEP 11-16, 1995 CL INST THEORET & EXPTL PHYS, MOSCOW, RUSSIA SP Russian Acad Sci, Dept Nucl Phys, Russian Fdn Basic Res, Inst Theoret & Exptl Phys, Int Sci Fdn, INFN, Lab Nazl Frascati, Italy HO INST THEORET & EXPTL PHYS ID SPECTROMETER; LEAR AB The branching ratios (Br) for the Pontecorvo reactions (p) over bar d --> n pi(0), n eta, n omega, n eta' and Delta(0)(1232)pi(0) are presented. The data were obtained at LEAR by stopping antiprotons in a liquid deuterium target. Outgoing mesons have been fully reconstructed. Assuming charge independence, Br((p) over bar d --> n pi(0)) was compared with measurements of the reaction (p) over bar d --> p pi(-). No substantial difference between Br's for the Pontecorvo reaction (p) over bar d --> p pi(-) in liquid and gaseous deuterium has been observed. The pi(0) pi(0)n Dalitz plot was used to identify the reaction (p) over bar d --> Delta(0) pi(0). C1 CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. UNIV MUNICH,D-80333 MUNICH,GERMANY. UNIV MAINZ,D-55099 MAINZ,GERMANY. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV LONDON QUEEN MARY & WESTFIELD COLL,LONDON E1 4NS,ENGLAND. UNIV KARLSRUHE,D-76021 KARLSRUHE,GERMANY. UNIV HAMBURG,D-22761 HAMBURG,GERMANY. CERN,CH-1211 GENEVA,SWITZERLAND. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. HUNGARIAN ACAD SCI,H-1525 BUDAPEST,HUNGARY. UNIV BONN,D-53115 BONN,GERMANY. RUHR UNIV BOCHUM,D-44780 BOCHUM,GERMANY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. SILESIAN UNIV,INST PHYS,PL-40007 KATOWICE,POLAND. RP Amsler, C (reprint author), UNIV ZURICH,CH-8057 ZURICH,SWITZERLAND. NR 9 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD AUG PY 1996 VL 59 IS 8 BP 1415 EP 1420 PG 6 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA VG182 UT WOS:A1996VG18200022 ER PT J AU Charlton, M Laricchia, G Feng, X Hangst, JS Hvelplund, P Knudsen, H Merrison, JP Uggerhoj, E Holzscheiter, MH Hughes, RJ AF Charlton, M Laricchia, G Feng, X Hangst, JS Hvelplund, P Knudsen, H Merrison, JP Uggerhoj, E Holzscheiter, MH Hughes, RJ TI Antihydrogen synthesis by collisions between antiprotons and positronium atoms SO PHYSICS OF ATOMIC NUCLEI LA English DT Article; Proceedings Paper CT 3rd International Conference on Nucleon-Antinucleon Physics CY SEP 11-16, 1995 CL INST THEORET & EXPTL PHYS, MOSCOW, RUSSIA SP Russian Acad Sci, Dept Nucl Phys, Russian Fdn Basic Res, Inst Theoret & Exptl Phys, Int Sci Fdn, INFN, Lab Nazl Frascati, Italy HO INST THEORET & EXPTL PHYS ID RARE-GAS SOLIDS; THERMAL-ACTIVATION; SLOW POSITRONS; PENNING TRAP; PHYSICS; IMPROVEMENT; MODERATION; ENERGIES; SURFACES; FILMS AB We overview the progress made recently in pursuit of antihydrogen formation by the interaction of cold antiprotons, held in a Penning frap, with injected positronium atoms. We describe the relevant details of the antiproton catching scheme, based upon the PS200 trap, and our goals before antihydrogen can be observed. A method of accumulating low-energy positrons to provide the required large bursts of positronium atoms is described. The antihydrogen-formation rate for the simplest reaction is estimated, and its implications for the production and detection scenario are examined. An experiment to observe the charge-conjugate reaction, namely hydrogen formation in proton-positronium collisions, is summarized. C1 AARHUS UNIV,INST PHYS & ASTRON,DK-800 AARHUS C,DENMARK. LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. RP Charlton, M (reprint author), UNIV LONDON UNIV COLL,DEPT PHYS & ASTRON,GOWER ST,LONDON WC1E 6BT,ENGLAND. OI merrison, jonathan/0000-0003-4362-6356 NR 47 TC 0 Z9 0 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD AUG PY 1996 VL 59 IS 8 BP 1474 EP 1481 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA VG182 UT WOS:A1996VG18200031 ER PT J AU Nadiga, BT Margolin, LG Smolarkiewicz, PK AF Nadiga, BT Margolin, LG Smolarkiewicz, PK TI Different approximations of shallow fluid flow over an obstacle SO PHYSICS OF FLUIDS LA English DT Article ID BOUSSINESQ EQUATIONS; WAVE-PROPAGATION; WATER; OCEAN; FORM AB Three different sets of shallow water equations, representing different levels of approximation are considered. The numerical solutions of these different equations for flow past bottom topography in several different flow regimes are compared. For several cases the full Euler solutions are computed as a reference, allowing the assessment of the relative accuracies of the different approximations. Further, the differences between the dispersive shallow water (DSW) solutions and those of the highly simplified, hyperbolic shallow water (SW) equations is studied as a guide to determining what level of approximation is required for a particular flow. First, the Green-Naghdi (GN) equations are derived as a vertically-integrated rational approximation of the Euler equations, and then the generalized Boussinesq (gB) equations are obtained under the further assumption of weak nonlinearity. A series of calculations, each assuming different values of a set of parameters-undisturbed upstream Froude number, and the height and width of the obstacle, are then presented and discussed. In almost all regions of the parameter space, the SW and DSW theories yield different results; it is only when the flows are entirely subcritical or entirely supercritical and when the obstacles are very wide compared to the depth of the fluid that the SW and DSW theories are in qualitative and quantitative agreement. It is also found that while the gB solutions are accurate only for small bottom topographies (less than 20% of the undisturbed fluid depth), the GN solutions are accurate for much larger topographies (up to 65% of the undisturbed fluid depth). The limitation of the gB approximation to small topographies is primarily due to the generation of large amplitude upstream propagating solitary waves at transcritical Froude numbers, and is consistent with previous analysis. The GN approximation, which makes no assumptions about the size of the nonlinearity, is thus verified to be a better system to use in cases where the bottom topographies are large or when the bottom topographies are moderate but the flow transcritical. (C) 1996 American Institute of Physics. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. RP Nadiga, BT (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 30 TC 28 Z9 28 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD AUG PY 1996 VL 8 IS 8 BP 2066 EP 2077 DI 10.1063/1.869009 PG 12 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA UX897 UT WOS:A1996UX89700008 ER PT J AU Shaing, KC Zarnstorff, MC Hsu, CT AF Shaing, KC Zarnstorff, MC Hsu, CT TI Orbit squeezing in a magnetic well SO PHYSICS OF PLASMAS LA English DT Article ID EDGE ELECTRIC-FIELD; H-MODE; TOKAMAK AB It is shown that the size of a charged particle's drift orbit is squeezed, i.e., reduced, in a magnetic well in tokamak plasmas. The squeezing factor depends on the energy of the particle, being larger for higher-energy particles. Therefore, for high-energy particles, the size of the drift orbit depends only on the magnetic geometry. These energy-independent drift orbits are also observed [J.A. Rome and Y.-K. M. Ping, Nucl. Fusion 19, 1193 (1979)]. The implications on the core confinement improvement physics and the confinement of the advanced fuel are discussed. (C) 1996 American Institute of Physics. C1 PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Shaing, KC (reprint author), UNIV TEXAS,INST FUS STUDIES,AUSTIN,TX 78712, USA. NR 11 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1996 VL 3 IS 8 BP 2843 EP 2845 DI 10.1063/1.871642 PG 3 WC Physics, Fluids & Plasmas SC Physics GA VA463 UT WOS:A1996VA46300001 ER PT J AU Peurrung, AJ Barlow, SE AF Peurrung, AJ Barlow, SE TI Characteristics of a weakly ionized non-neutral plasma SO PHYSICS OF PLASMAS LA English DT Article ID PURE ELECTRON-PLASMA; NONNEUTRAL PLASMA; TRANSPORT; EQUILIBRIA; COLLISIONS; THEOREM; CLOUDS; COLUMN; MASS AB A scheme that allows stable confinement of a weakly ionized non-neutral plasma is discussed. The method requires the forced rotation of the neutral gas within the trap about an axis that roughly coincides with the trap's magnetic and mechanical axes. A number of the basic equilibrium and nonequilibrium properties of such a trapped plasma are calculated. (C) 1996 American Institute of Physics. RP Peurrung, AJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 23 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1996 VL 3 IS 8 BP 2859 EP 2863 DI 10.1063/1.871645 PG 5 WC Physics, Fluids & Plasmas SC Physics GA VA463 UT WOS:A1996VA46300004 ER PT J AU Carreras, BA Newman, D Lynch, VE Diamond, PH AF Carreras, BA Newman, D Lynch, VE Diamond, PH TI A model realization of self-organized criticality for plasma confinement SO PHYSICS OF PLASMAS LA English DT Article ID TRANSPORT; AVALANCHES; DYNAMICS AB A model for plasma transport near marginal stability is presented. The model is based on subcritical resistive pressure-gradient-driven turbulence. Three-dimensional nonlinear calculations based on this model show effective transport for subcritical mean profiles. This model exhibits some of the characteristic properties of self-organized criticality. Perturbative transport techniques are used to elucidate the transport properties. Propagation of positive and negative pulses is studied. The observed results suggest a possible explanation of the apparent nonlocal effects observed with perturbative experiments in tokamaks. (C) 1996 American Institute of Physics. C1 UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. RP Carreras, BA (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Lynch, Vickie/J-4647-2012 OI Lynch, Vickie/0000-0002-5836-7636 NR 24 TC 185 Z9 185 U1 1 U2 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1996 VL 3 IS 8 BP 2903 EP 2911 DI 10.1063/1.871650 PG 9 WC Physics, Fluids & Plasmas SC Physics GA VA463 UT WOS:A1996VA46300010 ER PT J AU Redi, MH Budny, RV McCune, DC Miller, CO White, RB AF Redi, MH Budny, RV McCune, DC Miller, CO White, RB TI Simulations of alpha particle ripple loss from the International Thermonuclear Experimental Reactor SO PHYSICS OF PLASMAS LA English DT Article ID TFTR; DIFFUSION; TOKAMAKS; IONS AB Calculations of collisional stochastic ripple loss of alpha particles from the new 20 toroidal field (TF) coil International Thermonuclear Experimental Reactor (ITER) [Plasma Physics and Controlled Nuclear Fusion Research (International Atomic Energy Agency, Vienna, 1991), Vol. 3, p. 239] predict small alpha ripple losses, less than 0.4%, close to the loss calculated for the full current operation of the earlier 24 TF coil design. An analytic fit is obtained to the ITER ripple data field demonstrating the nonlinear height dependence of the ripple minimum for D-shaped ripple contours. In contrast to alpha loss simulations for the Tokamak Fusion Test Reactor (TFTR) [Fusion Technol. 21, 1324 (1992)], a simple Goldston, White, and Boozer stochastic loss criterion [Phys. Rev. Lett. 47, 647 (1981)] ripple loss model is found to require an increased renormalization of the stochastic threshold delta(s)/delta(GWB)>1. Effects of collisions, sawtooth broadening, and reversal of the grad-B drift direction are included in the particle following simulations. (C) 1996 American Institute of Physics. RP Redi, MH (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI White, Roscoe/D-1773-2013 OI White, Roscoe/0000-0002-4239-2685 NR 32 TC 16 Z9 17 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1996 VL 3 IS 8 BP 3037 EP 3042 DI 10.1063/1.871640 PG 6 WC Physics, Fluids & Plasmas SC Physics GA VA463 UT WOS:A1996VA46300024 ER PT J AU White, RB Goldston, RJ Redi, MH Budny, RV AF White, RB Goldston, RJ Redi, MH Budny, RV TI Ripple-induced energetic particle loss in tokamaks SO PHYSICS OF PLASMAS LA English DT Article ID CROSS-SECTION; TRANSPORT; DIFFUSION; IONS; PLASMAS; SYSTEMS; TFTR AB The threshold for stochastic transport of high energy trapped particles in a tokamak due to toroidal field ripple is calculated by explicit construction of primary resonances, and a numerical examination of the route to chaos. Critical field ripple amplitude is determined for loss. The expression is given in magnetic coordinates and makes no assumptions regarding shape or up-down symmetry. An algorithm is developed including the effects of prompt axisymmetic orbit loss, ripple trapping, convective banana flow, and stochastic ripple loss, which gives accurate ripple loss predictions for representative Tokamak Fusion Test Reactor [R. Hawryluk, Plasma Phys. Controlled Fusion 33, 1509 (1991)] and International Thermonuclear Experimental Reactor [K. Tomabechi, Proceedings of the 12th International Conference on Plasma Physics and Controlled Nuclear Fusion Research (International Atomic Energy Agency, Vienna, 1989), Vol. 3, p. 214] equilibria. The algorithm is extended to include the effects of collisions and drag, allowing rapid estimation of alpha particle loss in tokamaks. (C) 1996 American Institute of Physics. RP White, RB (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI White, Roscoe/D-1773-2013 OI White, Roscoe/0000-0002-4239-2685 NR 30 TC 31 Z9 31 U1 1 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1996 VL 3 IS 8 BP 3043 EP 3054 DI 10.1063/1.871641 PG 12 WC Physics, Fluids & Plasmas SC Physics GA VA463 UT WOS:A1996VA46300025 ER PT J AU Fruchtman, A AF Fruchtman, A TI A vacuum sheath propagation along a cathode SO PHYSICS OF PLASMAS LA English DT Article ID PLASMA OPENING SWITCH; HALL FIELD; PENETRATION; DIODE AB The velocity of propagation of a vacuum sheath along the cathode is calculated. A regime of parameters is identified in which, surprisingly, this velocity is lower for higher currents. (C) 1996 American Institute of Physics. C1 WEIZMANN INST SCI,DEPT PARTICLE PHYS,IL-76100 REHOVOT,ISRAEL. PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. NR 12 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1996 VL 3 IS 8 BP 3111 EP 3115 DI 10.1063/1.871657 PG 5 WC Physics, Fluids & Plasmas SC Physics GA VA463 UT WOS:A1996VA46300031 ER PT J AU Catto, PJ Knoll, DA Krasheninnikov, SI AF Catto, PJ Knoll, DA Krasheninnikov, SI TI Two-body similarity and its violation in tokamak edge plasmas SO PHYSICS OF PLASMAS LA English DT Article AB Scaling laws found under the assumption that two-body collisions dominate can be effectively used to benchmark complex multi-dimensional codes dedicated to investigating tokamak edge plasmas. The applicability of such scaling laws to the interpretation of experimental data, however, is found to be restricted to the relatively low plasma densities (<10(19) m(-3)) at which multistep processes, which break the two-body collision approximation, are unimportant. (C) 1996 American Institute of Physics. C1 IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. IV KURCHATOV ATOM ENERGY INST,MOSCOW 123182,RUSSIA. RP Catto, PJ (reprint author), MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139, USA. NR 8 TC 8 Z9 8 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1996 VL 3 IS 8 BP 3191 EP 3193 DI 10.1063/1.871624 PG 3 WC Physics, Fluids & Plasmas SC Physics GA VA463 UT WOS:A1996VA46300042 ER PT J AU Wietfeldt, FE Norman, EB AF Wietfeldt, FE Norman, EB TI The 17 keV neutrino SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE neutrino mass; kink searches ID DOUBLE-BETA-DECAY; INTERNAL BREMSSTRAHLUNG SPECTRUM; 17-KEV NEUTRINO; HEAVY-NEUTRINO; MASSIVE NEUTRINOS; ELECTRON-CAPTURE; MUON MOMENTUM; PION DECAY; NU-E; SEARCH AB A controversy over the possible existence of a 17 keV mass state coupled to the electron neutrino occurred during the period 1985-1993. A number of independent experiments found evidence for this state in nuclear decay spectra, while others did not. Ultimately a consensus that the 17 keV neutrino does not exist was reached. We review and evaluate the experiments that reported evidence for and against the 17 keV neutrino, and discuss the various issues of experimental systematics that contributed to the development and resolution of the controversy. We attempt to distill the lessons learned from this experience and draw some general conclusions that are relevant to future research. C1 UNIV CALIF BERKELEY,DIV NUCL SCI,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. NR 114 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD AUG PY 1996 VL 273 IS 3 BP 150 EP 197 PG 48 WC Physics, Multidisciplinary SC Physics GA VD336 UT WOS:A1996VD33600001 ER PT J AU Blume, M Elliott, R AF Blume, M Elliott, R TI Walter Marshall - Obituary SO PHYSICS TODAY LA English DT Item About an Individual C1 UNIV OXFORD,OXFORD,ENGLAND. RP Blume, M (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD AUG PY 1996 VL 49 IS 8 BP 82 EP 82 DI 10.1063/1.2807745 PN 1 PG 1 WC Physics, Multidisciplinary SC Physics GA VA660 UT WOS:A1996VA66000023 ER PT J AU Noyes, P AF Noyes, P TI Thomas Kuhn 1922-96 - Obituary SO PHYSICS WORLD LA English DT Item About an Individual RP Noyes, P (reprint author), STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 1 TC 0 Z9 0 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8585 J9 PHYS WORLD JI Phys. World PD AUG PY 1996 VL 9 IS 8 BP 50 EP 51 PG 2 WC Physics, Multidisciplinary SC Physics GA VA703 UT WOS:A1996VA70300028 ER PT J AU Burr, FA Burr, B Scheffler, BE Blewitt, M Wienand, U Matz, EC AF Burr, FA Burr, B Scheffler, BE Blewitt, M Wienand, U Matz, EC TI The maize repressor-like gene intensifier1 shares homology with the r1/b1 multigene family of transcription factors and exhibits missplicing SO PLANT CELL LA English DT Article ID NUCLEOTIDE-SEQUENCE; REGULATORY GENE; RECOMBINANT INBREDS; ANTHOCYANIN PATHWAY; DNA; PROTEINS; INTRON; EXPRESSION; RICH; ENCODES AB The recessive mutation intensifier1 of maize apparently causes an overall increase in flavonoid production in the aleurone, The mechanism by which this is achieved is not understood. We have succeeded in cloning the intensifier1 gene by transposon tagging with Suppressor-mutator and found, by sequence analyses, that it shares homology with known transcription factors in the anthocyanin pathway, in particular the r1/b1 multigene family in maize. Two cDNAs and a genomic clone were completely sequenced, and together they showed that the transcripts were misspliced. The frequency of missplicing was investigated by polymerase chain reaction analyses and sequencing of the individual introns. These studies indicate that very little functional transcript was made. Indeed, missplicing may be a mechanism for reducing the levels of a transcription factor that, when present, acts as a repressor of anthocyanin biosynthesis. C1 UNIV HAMBURG,INST ALLGEMEINE BOT,D-22609 HAMBURG,GERMANY. UNIV HAMBURG,BOT GARDENS,D-22609 HAMBURG,GERMANY. RP Burr, FA (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. OI Scheffler, Brian/0000-0003-1968-8952 NR 42 TC 63 Z9 80 U1 1 U2 6 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 1040-4651 J9 PLANT CELL JI Plant Cell PD AUG PY 1996 VL 8 IS 8 BP 1249 EP 1259 PG 11 WC Biochemistry & Molecular Biology; Plant Sciences; Cell Biology SC Biochemistry & Molecular Biology; Plant Sciences; Cell Biology GA VE732 UT WOS:A1996VE73200004 PM 8776895 ER PT J AU Opgenorth, DC Smart, CD Louws, FJ deBruijn, FJ Kirkpatrick, BC AF Opgenorth, DC Smart, CD Louws, FJ deBruijn, FJ Kirkpatrick, BC TI Identification of Xanthomonas fragariae field isolates by rep-PCR genomic fingerprinting SO PLANT DISEASE LA English DT Article ID POLYMERASE CHAIN-REACTION; REPETITIVE DNA-SEQUENCES; BACTERIA; STRAINS AB Xanthomonas fragariae, the causal organism of angular leaf spot on cultivated strawberry (Fragaria x ananassa), is an economically important pathogen of nursery stock in California. The ability to reliably detect this pathogen in a timely manner is crucial for the production and timely distribution of disease-free nursery stock. Pathogenicity testing for this disease requires excessive time, and the bacterium grows slowly on standard culture medium. A medium, similar to that used for culturing Xylella fastidiosa, allowed more consistent recovery of X. fragariae ii-om infected strawberry plants. Using the polymerase chain reaction (PCR) with primers that anneal to dispersed repetitive bacterial sequences (rep-PCR), we generated genomic fingerprints of reference strains oi X. fragariae (ATCC 33239 and 33240). These fingerprints were used, in turn, to accurately identify X. fragariae field isolates collected over the last 5 years from nurseries in California. The rep-PCR fingerprint results agree with pathogenicity test results, require much less time than the pathogenicity test, and have greater specificity than indirect enzyme-linked immunosorbent assay for identifying X. fragariae from field plants. For these reasons, rep-PCR is the fastest and most accurate method for the current identification of X. fragariae and it constitutes a useful tool for the production of disease-free strawberry nursery stocks. C1 UNIV CALIF DAVIS,DEPT PLANT PATHOL,DAVIS,CA 95616. CALIF DEPT FOOD & AGR,SACRAMENTO,CA 95814. MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,NSF CTR MICROBIAL ECOL,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT MICROBIOL,E LANSING,MI 48824. NR 30 TC 33 Z9 39 U1 1 U2 3 PU AMER PHYTOPATHOLOGICAL SOC PI ST PAUL PA 3340 PILOT KNOB ROAD, ST PAUL, MN 55121 SN 0191-2917 J9 PLANT DIS JI PLANT DIS. PD AUG PY 1996 VL 80 IS 8 BP 868 EP 873 PG 6 WC Plant Sciences SC Plant Sciences GA UY568 UT WOS:A1996UY56800008 ER PT J AU Kaye, SM AF Kaye, SM TI Fifth IAEA technical committee meeting US-Japan workshop on H-mode Physics - Preface SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Editorial Material RP Kaye, SM (reprint author), PRINCETON UNIV,PPPL,PRINCETON,NJ 08544, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1089 EP 1089 PG 1 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200001 ER PT J AU Goldston, RJ AF Goldston, RJ TI Reactor compatibility of the H-mode SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB ID REVERSED MAGNETIC SHEAR; HIGH-BETA-P; CONFINEMENT; STABILITY AB H-mode operation presents challenges for ITER and for reactor application in the areas of performance, accessibility, sustainability and divertor compatibility. Some issues are more severe for ITER, while others are more problematic for an economic fusion reactor producing 3 MW m(-2) of neutron flux to its walls. The problems that are more severe for ITER include the power requirements for the H-mode, and confinement uncertainties. Problems which are more severe for a reactor include capability for high beta* operation, the role of the Greenwald density limit, and divertor compatibility. Within the present ITER concept, it would be very helpful to have a well defined upgrade path for the auxiliary heating systems, including options for strong profile control. The world fusion research programme should maintain a major focus on improving the reactor compatibility of the H-mode, with an eye to the special advantages of H-mode plasmas with strong shaping. RP Goldston, RJ (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1161 EP 1172 DI 10.1088/0741-3335/38/8/008 PG 12 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200008 ER PT J AU Shaing, KC Hsu, CT Zhang, YZ AF Shaing, KC Hsu, CT Zhang, YZ TI Extended H-mode theory and critical local parameters SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB ID EDGE ELECTRIC-FIELD; POLOIDAL ROTATION; TRANSITION; TOKAMAK AB H-mode theory (Shaing and Crume Jr 1989 Phys. Rev. Lett. 63 2369) is extended to include realistic effects such as charge-exchange momentum loss and the magnetic stresses. Local critical plasma parameters for the onset of the bifurcation are obtained and can be compared quantitatively with experimental measurements. It is concluded that local critical parameters are more meaningful in quantifying H-mode transition than the global power threshold scaling law. C1 PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. INT CTR THEORET PHYS,TRIESTE,ITALY. RP Shaing, KC (reprint author), UNIV TEXAS,INST FUS STUDIES,AUSTIN,TX 78712, USA. NR 16 TC 0 Z9 0 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1331 EP 1335 DI 10.1088/0741-3335/38/8/032 PG 5 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200032 ER PT J AU Ware, AS Terry, PW Diamond, PH Carreras, BA AF Ware, AS Terry, PW Diamond, PH Carreras, BA TI Transport reduction via shear flow modification of the cross phase SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB ID GRADIENT-DRIVEN TURBULENCE; TRANSITION; GENERATION AB As a model example of the effect of E x B shear flow on the cross phase between electrostatic potential and pressure fluctuations, a nonlinear theory of resistive pressure gradient driven turbulence (RPGDT) in a shear flow is presented. This work builds on numerical studies of RPGDT, which have shown that both flow shear and curvature can affect the cross phase as well as the fluctuation levels. In this work, we show that the effect of shear flow on transport can be expressed through the temporal response of pressure to potential. It is shown heuristically that even in the case where the fluctuation levels are not modified, the flow shear still acts to reduce the phase angle between potential and pressure fluctuations, thereby suppressing transport. The scaling of the cross phase with flow shear and flow curvature is presented. C1 UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Ware, AS (reprint author), UNIV WISCONSIN,MADISON,WI 53706, USA. NR 11 TC 35 Z9 36 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1343 EP 1347 DI 10.1088/0741-3335/38/8/034 PG 5 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200034 ER PT J AU Bush, CE Budny, RV Sabbagh, SA Efthimion, PC Bell, RE Synakowski, EJ Taylor, G LeBlanc, B Paul, SF AF Bush, CE Budny, RV Sabbagh, SA Efthimion, PC Bell, RE Synakowski, EJ Taylor, G LeBlanc, B Paul, SF TI Combined H-modes in DD and DT plasmas in TFTR SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB ID TOKAMAK AB Circular limiter DD and DT H-modes have been obtained through transitions in supershot and high-poloidal-beta plasmas in TFTR. High tritium concentrations have been realized, with tritium fuelling mostly through the heating beams, varying from all D-0 to all T-0 beams. Density fluctuations were reduced by a factor of two across the plasma and T-i and V-phi profiles have features consistent with simultaneous transport barriers in the plasma core and edge. chi(i) values from TRANSP decrease by a factor of 2 to 5 in these regions at the transition and remain low until the onset of ELMs. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37830. RP Bush, CE (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Sabbagh, Steven/C-7142-2011 NR 7 TC 2 Z9 2 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1353 EP 1357 DI 10.1088/0741-3335/38/8/036 PG 5 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200036 ER PT J AU Janos, A Hastie, J McGuire, K Fredrickson, E AF Janos, A Hastie, J McGuire, K Fredrickson, E TI Bursts of electron cyclotron emission during ELMs and high beta disruptions in TFTR SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB AB Large ELM events in TFTR are often accompanied by short, intense bursts of electron cyclotron emission. A unique combination of two fast grating polychromator instruments located at different toroidal positions is used to measure the emission and characterize these bursts, which exhibit strong toroidal asymmetries. Bursts are compared to those which occur early in the thermal quench phase of high beta disruptions, the only other time that bursts occur with comparable robustness. In these disruptions, bursts are localized to the vicinity of the ballooning mode, a medium toroidal mode number (n = 10-20) precursor, localized toroidally, poloidally, and radially, which triggers the disruption. Rapid loss of particles and sudden rapid cooling occurs. In both cases, bursting can be explained not in terms of excitation of enhanced emission but rather in the reduction of absorption of thermal emission. Bursting is consistent with a modification of the electron distribution function f(e) due to a rapid energy or particle exchange between hot electrons and cold electrons from the edge, momentarily reducing the velocity gradient of f(e) in the thermal region. This model is qualitatively and quantitatively consistent with experiment, predicting for example emission enhancement factors of approximate to 10. RP Janos, A (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 10 TC 5 Z9 5 U1 2 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1373 EP 1379 DI 10.1088/0741-3335/38/8/039 PG 7 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200039 ER PT J AU Jong, RA Porter, GD Groebner, RJ Lasnier, CJ AF Jong, RA Porter, GD Groebner, RJ Lasnier, CJ TI Effect of ELMS on the SOL plasma in DIII-D SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB AB We have studied the evolution of the edge plasma in VH-mode discharges in DIII-D, by following the changes in the radial profiles of the density and temperature, in the core plasma near the separatrix and in the scrape-off-layer (SOL) plasma outside the separatrix. The electron density and temperature profiles in the SOL do not show any significant difference between the ELM-free H-mode and VH-mode phases of the discharge. In the ELMing phase, the density profile broadens during an ELM, forming a high-density (n(e) > 1 x 10(19) m(-3)) plateau that extends out into the SOL to the limit of the measurement. This plateau persists between the ELMs, although the density in the SOL does relax somewhat between the ELMs, with a characteristic time that can be greater than 10 ms, much longer than the sonic particle flow time to the divertor plates. The density scale length increases with the ELM background, as measured by the photodiode viewing the divertor floor nearest to, but outside, the outer strike point. The electron temperature profile in the SOL also broadens during an ELM, but the broad profile does not persist between ELMs. C1 GEN ATOM CO,SAN DIEGO,CA 92121. RP Jong, RA (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 7 TC 9 Z9 9 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1381 EP 1385 DI 10.1088/0741-3335/38/8/040 PG 5 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200040 ER PT J AU Lebedev, VB Diamond, PH Medvedev, MM Yushmanov, PN Carreras, BA AF Lebedev, VB Diamond, PH Medvedev, MM Yushmanov, PN Carreras, BA TI A simple dynamical model of edge localized mode phenomena SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB ID DIII-D; DISCHARGES; ENERGY AB A dynamical model of edge-localized mode (ELM) phenomena is presented. It combines the paradigms of the L-H transition mediated by electric field shear induced suppression and generation with a simplified description of MHD instability and with a transport analysis of the plasma edge. In the parameter regime characteristic of an H-mode plasma, the model exhibits a transition to stationary relaxation oscillations (i.e. stable limit cycle behaviour) corresponding to ELMs. The dependence of ELM frequency, amplitude etc on the heating power P-in and other control parameters is studied. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Lebedev, VB (reprint author), UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093, USA. NR 8 TC 1 Z9 1 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1397 EP 1400 DI 10.1088/0741-3335/38/8/043 PG 4 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200043 ER PT J AU Sesnic, S Bell, R Dunlap, J Kaita, R Kaye, S LeBlanc, B Okabayashi, M Ono, M Tighe, W AF Sesnic, S Bell, R Dunlap, J Kaita, R Kaye, S LeBlanc, B Okabayashi, M Ono, M Tighe, W TI Interaction of ELMs with the core transport barrier in CH-mode in PBX-M SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB ID HEATED DIVERTOR DISCHARGES; DIII-D; CONFINEMENT; TOKAMAK AB An addition of ion Bernstein wave power of only a tenth of the neutral beam power into an H-mode causes the formation of a core transport barrier. At the location of the barrier, reduced ELM losses in the soft x-ray profile are observed. During the IBW-modified ELM, one can observe enhanced fluctuations in the soft x-ray fluctuation profile over the whole of the observed frequency range. In the region of the core transport barrier, the enhancement of fluctuations seems to be strongly reduced. The ELM loss propagates to the core with a velocity greater than that which would be consistent with a normal energy diffusion process. C1 ORNL,OAK RIDGE,TN 37381. RP Sesnic, S (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1401 EP 1406 DI 10.1088/0741-3335/38/8/044 PG 6 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200044 ER PT J AU Hahm, TS Burrell, KH AF Hahm, TS Burrell, KH TI Role of flow shear in enhanced core confinement regimes SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB ID POLOIDAL ROTATION; SUPPRESSION; TRANSITION; TURBULENCE; TRANSPORT; TOKAMAK; PLASMA AB The importance of the E x B Bow shear in various enhanced confinement regimes is discussed in terms of the turbulence suppression criterion in general toroidal geometry. This criterion is then further generalized to include the poloidal angle dependence of the equilibrium electrostatic potential. The implication of the recently observed in-out asymmetry in the fluctuation behaviour in DIII-D VH-mode is discussed. C1 GEN ATOM CO,SAN DIEGO,CA 92186. RP Hahm, TS (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 18 TC 17 Z9 17 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1427 EP 1431 DI 10.1088/0741-3335/38/8/049 PG 5 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200049 ER PT J AU Lao, LL Burrell, KH Casper, TS Chan, VS Chu, MS Forest, CB Groebner, RJ Hinton, FL Kawano, Y Lazarus, EA LinLiu, YR Mauel, ME Meyer, WH Miller, RL Navratil, GA Osborne, TH Rettig, CL Rewoldt, G Rice, BW Stallard, BW Strait, EJ Taylor, TS Tang, WM Turnbull, AD Waltz, RE AF Lao, LL Burrell, KH Casper, TS Chan, VS Chu, MS Forest, CB Groebner, RJ Hinton, FL Kawano, Y Lazarus, EA LinLiu, YR Mauel, ME Meyer, WH Miller, RL Navratil, GA Osborne, TH Rettig, CL Rewoldt, G Rice, BW Stallard, BW Strait, EJ Taylor, TS Tang, WM Turnbull, AD Waltz, RE TI Confinement and stability of DIII-D negative central shear discharges SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB ID REVERSED MAGNETIC SHEAR AB Negative central magnetic shear (NCS) discharges with beta(N) less than or equal to 4, H less than or equal to 3 and up to 80% of the current non-inductively driven are reproducibly produced in the DIII-D tokamak. Strong peaking of T-i, plasma rotation and, in some cases, n(e) are observed inside the NCS region. Transport analysis shows that the core ion thermal diffusivity is substantially reduced and near the neoclassical value after the formation of the internal transport barrier. The negative central shear is necessary but not sufficient for the formation of this transport barrier. The power required for the formation appears to increase with the toroidal magnetic field. The high performance phase of H-mode NCS discharges often ends with an ELM-like collapse initiated from the edge whereas the L-mode discharges which have a more peaked pressure profile tend to end with a more global n = 1 MHD event. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. JAPAN ATOM ENERGY RES INST,NAKA,IBARAKI 31101,JAPAN. OAK RIDGE NATL LAB,OAK RIDGE,TN. COLUMBIA UNIV,NEW YORK,NY. UNIV CALIF LOS ANGELES,LOS ANGELES,CA. PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Lao, LL (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA, USA. OI Mauel, Michael/0000-0003-2490-7478 NR 7 TC 4 Z9 4 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1439 EP 1443 DI 10.1088/0741-3335/38/8/051 PG 5 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200051 ER PT J AU Osborne, TH Burrell, KH Chu, MS Forest, CB Lazarus, EA LaHaye, RJ Rettig, CL Rice, BW Staebler, GM Strait, EJ Taylor, TS Turnbull, AD AF Osborne, TH Burrell, KH Chu, MS Forest, CB Lazarus, EA LaHaye, RJ Rettig, CL Rice, BW Staebler, GM Strait, EJ Taylor, TS Turnbull, AD TI High performance low and high q discharges in DIII-D SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB ID CONFINEMENT AB The high performance H-mode regime on DIII-D has been extended to both low q and high q (high beta(p)) operation. In high current operation, VH-mode discharges were obtained for the first time with I-p(MA)/B-T(T)> 1. These discharges had q(95) = 3.4, H = 2.9, beta(N) = 3, and beta(T) tau(E) = beta(T) tau(E) was improved by approximately 50% over previous results. These discharges were obtained with neutral beam injection during the plasma current ramp up which maintained the axial q above 1. In low current operation, neutral beam heated discharges with 100% of the plasma current from non-inductive sources were obtained at high q, q(95) = 15, with beta(N) = 3.9, H = 3.1 and beta(p) = 4.9. These discharges represent an extension of the high performance regime to q(95) > 7.2, which was made possible by reduction in the locked mode low density limit, as the result of improvements in the magnetic field error correcting coils. These low current discharges do not exhibit some of the standard signatures of VH-mode, but appear to represent a new regime of improved PI-mode confinement. Similar, non-VH-mode, high energy confinement discharges were obtained at low density and moderate q. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. UNIV CALIF LOS ANGELES,LOS ANGELES,CA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Osborne, TH (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1451 EP 1454 DI 10.1088/0741-3335/38/8/053 PG 4 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200053 ER PT J AU Tighe, W LeBlanc, B Ono, M Sesnic, S AF Tighe, W LeBlanc, B Ono, M Sesnic, S TI Development of toroidal velocity and ion temperature shear during the IBW-induced, core H-mode in PBX-M SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 5th IAEA Technical Committee Meeting/US-Japan Workshop on H-Mode Physics CY SEP 18-20, 1995 CL PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ SP IAEA HO PRINCETON UNIV, PRINCETON PLASMA PHYS LAB ID TOKAMAK; PLASMA; POWER AB In this paper we examine the evolution of the gradients in toroidal velocity, V-phi, and ion temperature, T-i, during the CH-mode in PBX-M. This enhanced confinement mode develops from the H-mode following the application of IBW power and is characterized by strong density peaking and the formation of significant gradients in both toroidal velocity and ion temperature. The radial profiles of both the toroidal velocity and the ion temperature are obtained from the PBX-M charge exchange recombination spectroscopy (CHERS) diagnostic. A significant IBW power threshold is observed in the formation of the gradients. A power step of only 25 kW-from 200 to 225 kW-marks the onset. Details of the evolution of the gradients are given and, in particular, the variation with IBW power is described. RP Tighe, W (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08453, USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1996 VL 38 IS 8 BP 1469 EP 1474 DI 10.1088/0741-3335/38/8/057 PG 6 WC Physics, Fluids & Plasmas SC Physics GA VF192 UT WOS:A1996VF19200057 ER PT J AU Coverdale, CA Darrow, CB Decker, CD Naumova, NM Esirkepov, TZ Sakharov, AS Bulanov, SV Mori, WB Tzeng, KC AF Coverdale, CA Darrow, CB Decker, CD Naumova, NM Esirkepov, TZ Sakharov, AS Bulanov, SV Mori, WB Tzeng, KC TI Properties of the spectra of relativistically strong laser pulses in an underdense plasma SO PLASMA PHYSICS REPORTS LA English DT Article ID STIMULATED RAMAN-SCATTERING; IRRADIATED PLASMAS; BACKSCATTER; ULTRASHORT AB An experimental study and a particle-in-cell (PIG) simulation of the plasma-wave breaking and stimulated backward Raman scattering (SBRS) in the interaction of sub-picosecond laser pulses with an underdense plasma are carried out. The results of the experiment show that the spectrum of backscattered radiation is strongly modulated; the structure of modulations depends on the plasma density and the laser pulse intensity and exhibits pronounced symmetry. It is found that the SBRS saturates at the same pulse intensity at which the modulations of the SBRS spectrum appear. A one-dimensional PIC simulation also demonstrates the spectral modulation of scattered radiation as well as the appearance of modulations in the transmitted radiation spectrum during the pulse propagation. C1 RUSSIAN ACAD SCI,INST GEN PHYS,MOSCOW 117942,RUSSIA. MOSCOW INST PHYS & TECHNOL,MOSCOW 141700,RUSSIA. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. RP Coverdale, CA (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. RI Bulanov, Sergei/A-1721-2013 NR 26 TC 11 Z9 11 U1 1 U2 6 PU MAIK NAUKA/INTERPERIODICA PUBL PI WOODBURY PA C/O AMERICAN INST PHYSICS, 500 SUNNYSIDE BLVD, MEMBER SUBSCRIBER SERVICES, WOODBURY, NY 11797-2999 SN 1063-780X J9 PLASMA PHYS REP JI Plasma Phys. Rep. PD AUG PY 1996 VL 22 IS 8 BP 617 EP 624 PG 8 WC Physics, Fluids & Plasmas SC Physics GA VG179 UT WOS:A1996VG17900003 ER PT J AU Cohen, RH Rognlien, TD AF Cohen, RH Rognlien, TD TI Electron kinetics in radio-frequency magnetic fields of inductive plasma sources SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article ID SIMULATION; DISCHARGE; MODEL AB The influence of the radio-frequency (RF) electromagnetic field on electron dynamics in analysed both analytically and numerically, with an emphasis on the magnetic field, B, The magnetic field can be important for inductive plasma sources or other plasmas in which the rapid spatial decay of the electric field arising from a skin effect produces a large B via faraday's law. Principal consequences of including B are a change in the velocity component heated, a reduction in the electron density in the RF-fieid region, both instantaneous and time-averaged, and a reduction in the magnitude of the heating by the inductive fields, both at the level of individual particles and averaged over an isotropic distribution. We calculate analytical expressions for the instantaneous and averaged density reduction and the single-particle heating rates, and find good agreement with results from a multi-particle orbit code. We also give numerical results for the heating rate averaged over a Maxwellian distribution. The results are contrasted with those obtained previously when B was neglected. RP Cohen, RH (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 19 TC 44 Z9 44 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD AUG PY 1996 VL 5 IS 3 BP 442 EP 452 DI 10.1088/0963-0252/5/3/013 PG 11 WC Physics, Fluids & Plasmas SC Physics GA VF714 UT WOS:A1996VF71400013 ER PT J AU Bonivert, WD Cushnie, G AF Bonivert, WD Cushnie, G TI The Resource Center pilot program SO PLATING AND SURFACE FINISHING LA English DT Editorial Material C1 CAI ENGN,OAKTON,VA 22124. RP Bonivert, WD (reprint author), SANDIA NATL LABS,M-S 9404,BOX 969,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ELECTROPLATERS SOC INC PI ORLANDO PA 12644 RESEARCH PKWY, ORLANDO, FL 32826-3298 SN 0360-3164 J9 PLAT SURF FINISH JI Plat. Surf. Finish. PD AUG PY 1996 VL 83 IS 8 BP 36 EP 38 PG 3 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films SC Metallurgy & Metallurgical Engineering; Materials Science GA UZ227 UT WOS:A1996UZ22700015 ER PT J AU Bain, RL Overend, RP AF Bain, RL Overend, RP TI New gasification technology offers promise for biomass plants SO POWER ENGINEERING LA English DT Article RP Bain, RL (reprint author), NATL RENEWABLE ENERGY LAB,DEPT ENERGY,GOLDEN,CO, USA. OI Overend, Ralph/0000-0002-5442-0890 NR 2 TC 1 Z9 1 U1 0 U2 2 PU PENNWELL PUBL CO ENERGY GROUP PI TULSA PA 1421 S SHERIDAN RD PO BOX 1260, TULSA, OK 74101 SN 0032-5961 J9 POWER ENG JI Power Eng. PD AUG PY 1996 VL 100 IS 8 BP 32 EP & PG 4 WC Energy & Fuels; Engineering, Multidisciplinary SC Energy & Fuels; Engineering GA VC734 UT WOS:A1996VC73400021 ER PT J AU Singh, PP AF Singh, PP TI The origins of phase stability in ordered and disordered Ni-Pt alloys SO PRAMANA-JOURNAL OF PHYSICS LA English DT Article DE phase stability; ordered alloys; disordered alloys ID COHERENT-POTENTIAL-APPROXIMATION; GENERALIZED PERTURBATION METHOD; ATOMIC-SPHERE APPROXIMATION; SUBSTITUTIONAL ALLOYS; ELECTRONIC-STRUCTURE; COMPOSITIONAL ORDER; METALLIC ALLOYS; CHARGE; 1ST-PRINCIPLES AB Using the atomic-sphere approximation formulation of the Korringa-Kohn-Rostoker coherent potential approximation (KKR CPA) method, we have studied the effects of relativity on the electronic structure of ordered and substitutionally disordered Ni-Pt alloys. The inclusion of mass-velocity and Darwin terms are found to be essential for describing the experimentally observed ground-state properties. For the stability of disordered Ni-Pt alloys we find that, in addition to relativity, the minimization of charge-transfer effects are important. We also find that the treatment of ordering tendencies based on the band energy term alone is not sufficiently accurate for alloys with charge-transfer effects. Further analysis, in terms of basis functions, densities of states and non-spherically averaged charge densities, indicate the importance of s- and d-electrons of Pt for the stability of both ordered and disordered Ni-Pt alloys. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Singh, PP (reprint author), INDIAN INST TECHNOL,DEPT PHYS,BOMBAY 400076,MAHARASHTRA,INDIA. NR 23 TC 3 Z9 3 U1 1 U2 2 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0304-4289 J9 PRAMANA-J PHYS JI Pramana-J. Phys. PD AUG PY 1996 VL 47 IS 2 BP 99 EP 108 DI 10.1007/BF02847296 PG 10 WC Physics, Multidisciplinary SC Physics GA VM584 UT WOS:A1996VM58400001 ER PT J AU Fried, LE Souers, PC AF Fried, LE Souers, PC TI BKWC: An empirical BKW parametrization based on cylinder test data SO PROPELLANTS EXPLOSIVES PYROTECHNICS LA English DT Article AB A database containing mostly cylinder test data for 42 explosives composed of C, N, O, H, F, and Cl was collected. The resulting detonation velocities, C-J pressures, adiabat energies, and total energies of detonation were used to reparametrize the BKW equation of state for the CHEETAH thermochemical code. The resulting parameter set, referred to as BKWC, reproduces detonation velocities and adiabat energies better than previous BKW parameterizations. The BKWR equation of state is found to be slightly better in yielding C-J pressures. C1 Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94550 USA. RP Fried, LE (reprint author), Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94550 USA. RI Fried, Laurence/L-8714-2014 OI Fried, Laurence/0000-0002-9437-7700 NR 33 TC 31 Z9 31 U1 0 U2 4 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0721-3115 J9 PROPELL EXPLOS PYROT JI Propellants Explos. Pyrotech. PD AUG PY 1996 VL 21 IS 4 BP 215 EP 223 DI 10.1002/prep.19960210411 PG 9 WC Chemistry, Applied; Engineering, Chemical SC Chemistry; Engineering GA V2978 UT WOS:000169019700010 ER PT J AU Heller, J Kolbert, AC Larsen, R Ernst, M Bekker, T Baldwin, M Prusiner, SB Pines, A Wemmer, DE AF Heller, J Kolbert, AC Larsen, R Ernst, M Bekker, T Baldwin, M Prusiner, SB Pines, A Wemmer, DE TI Solid-state NMR studies of the prion protein H1 fragment SO PROTEIN SCIENCE LA English DT Article DE chemical shift; prion peptides; rotational resonance; secondary structure; solid-state NMR ID NUCLEAR-MAGNETIC-RESONANCE; ROTATIONAL RESONANCE; MAGIC-ANGLE; SECONDARY STRUCTURE; CHEMICAL-SHIFTS; CONFORMATIONAL TRANSITIONS; POLYCRYSTALLINE SOLIDS; TRANSGENIC MICE; CULTURED-CELLS; ALPHA-HELICES AB Conformational changes in the prion protein (PrP) seem to be responsible for prion diseases. We have used conformation-dependent chemical-shift measurements and rotational-resonance distance measurements to analyze the conformation of solid-state peptides lacking long-range order, corresponding to a region of PrP designated H1. This region is predicted to undergo a transformation of secondary structure in generating the infectious form of the protein. Solid-state NMR spectra of specifically C-13-enrrched samples of H1, residues 109-122 (MKHMAGAAAAGAVV) of Syrian hamster PrP, have been acquired under cross-polarization and magic-angle spinning conditions. Samples lyophilized from 50% acetonitrile/50% water show chemical shifts characteristic of a beta-sheet conformation in the region corresponding to residues 112-121, whereas samples lyophilized from hexafluoroisopropanol display shifts indicative of alpha-helical secondary structure in the region corresponding to residues 113-117. Complete conversion to the helical conformation was not observed and conversion from alpha-helix back to beta-sheet, as inferred from the solid-state NMR spectra, occurred when samples were exposed to water. Rotational-resonance experiments were performed on seven doubly C-13-labeled H1 samples dried from water. Measured distances suggest that the peptide is in an extended, possibly beta-strand, conformation. These results are consistent with the experimental observation that PrP can exist in different conformational states and with structural predictions based on biological data and theoretical modeling that suggest that H1 may play a key role in the conformational transition involved in the development of prion diseases. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,GRAD GRP BIOPHYS,BERKELEY,CA 94720. UNIV CALIF SAN FRANCISCO,DEPT NEUROL,SAN FRANCISCO,CA 94143. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. RI Ernst, Matthias/A-6732-2010; larsen, russell/H-3443-2013 OI Ernst, Matthias/0000-0002-9538-6086; FU NIA NIH HHS [AG02132, AG08967]; NINDS NIH HHS [NS14069] NR 53 TC 80 Z9 80 U1 1 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD AUG PY 1996 VL 5 IS 8 BP 1655 EP 1661 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VA138 UT WOS:A1996VA13800019 PM 8844854 ER PT J AU Chayen, NE Boggon, TJ Cassetta, A Deacon, A Gleichmann, T Habash, J Harrop, SJ Helliwell, JR Nieh, YP Peterson, MR Raftery, J Snell, EH Hadener, A Niemann, AC Siddons, DP Stojanoff, V Thompson, AW Ursby, T Wulff, M AF Chayen, NE Boggon, TJ Cassetta, A Deacon, A Gleichmann, T Habash, J Harrop, SJ Helliwell, JR Nieh, YP Peterson, MR Raftery, J Snell, EH Hadener, A Niemann, AC Siddons, DP Stojanoff, V Thompson, AW Ursby, T Wulff, M TI Trends and challenges in experimental macromolecular crystallography SO QUARTERLY REVIEWS OF BIOPHYSICS LA English DT Review ID PROTEIN CRYSTAL-GROWTH; X-RAY-DIFFRACTION; SYNCHROTRON LAUE METHOD; EGG-WHITE LYSOZYME; ANGLE NEUTRON-SCATTERING; DATA-COLLECTION SYSTEM; ELECTRON-DENSITY MAPS; WEISSENBERG CAMERA; RADIATION-DAMAGE; PHASE-DIAGRAM C1 UNIV MANCHESTER,DEPT CHEM,MANCHESTER M13 9PL,LANCS,ENGLAND. UNIV BASEL,DEPT CHEM,BASEL,SWITZERLAND. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. EUROPEAN MOL BIOL LAB,F-38042 GRENOBLE,FRANCE. ESRF,GRENOBLE,FRANCE. RP Chayen, NE (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,BIOPHYS SECT,LONDON SW7 2BZ,ENGLAND. RI stojanoff, vivian /I-7290-2012; Helliwell, John /C-4587-2014 OI stojanoff, vivian /0000-0002-6650-512X; Helliwell, John /0000-0002-0520-7540 FU Wellcome Trust NR 214 TC 70 Z9 72 U1 2 U2 10 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0033-5835 J9 Q REV BIOPHYS JI Q. Rev. Biophys. PD AUG PY 1996 VL 29 IS 3 BP 227 EP 278 PG 56 WC Biophysics SC Biophysics GA VY475 UT WOS:A1996VY47500002 PM 8968112 ER PT J AU Schwartz, JL Cowan, J Grdina, DJ Weichselbaum, RR AF Schwartz, JL Cowan, J Grdina, DJ Weichselbaum, RR TI Attenuation of G(2)-phase cell cycle checkpoint control is associated with increased frequencies of unrejoined chromosome breaks in human tumor cells SO RADIATION RESEARCH LA English DT Article ID HAMSTER OVARY CELLS; SINGLE-DONOR; LINES; RADIOSENSITIVITY; SENSITIVITY; DELAY; MUTATION; G2; APOPTOSIS; CAFFEINE AB To test the hypothesis that attenuation in G(2)-phase checkpoint control leads to elevated frequencies of unrejoined chromosome breaks in mitosis, the relationship between G(2)-phase cell cycle checkpoint control and unrejoined chromosome break frequencies after radiation exposure was examined in cells of 10 human tumor cell lines: 8 squamous cell carcinoma cell lines and 2 lymphoblastoid cell lines, Most of the delay in progression through the cell cycle seen in the first cell cycle after radiation exposure in these cell lines was due to blocks in G(2) phase, and there were large cell line-dependent variations in the length of the G(2)-phase block. There was a highly significant inverse correlation between the length of G(2)-phase delay after radiation exposure and the frequency of induced unrejoined chromosome breaks seen as chromosome terminal deletions in mitosis. This observation supports the hypothesis that the signal for G(2)-phase delay in mammalian cells is an unrejoined chromosome break and that attenuation of G(2)-phase checkpoint control allows cells with unrejoined breaks to progress into mitosis, Attenuation in G(2)-phase checkpoint control was not associated with alterations in the frequency of induced chromosome rearrangements, suggesting that most chromosome rearrangements develop prior to G(2) phase, and there was no significant relationship between the length of G(2)-phase delay and inherent radiation sensitivity, suggesting that unrejoined chromosome breaks are not the primary toxic lesion induced by radiation in mammalian cells. (C) 1996 by Radiation Research Society. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. UNIV CHICAGO,DEPT RADIAT & CELLULAR ONCOL,CHICAGO,IL 60637. FU NCI NIH HHS [CA-37435, CA 42596] NR 23 TC 29 Z9 31 U1 0 U2 0 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD AUG PY 1996 VL 146 IS 2 BP 139 EP 143 DI 10.2307/3579585 PG 5 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA VA384 UT WOS:A1996VA38400003 PM 8693063 ER PT J AU Schwartz, JL Mustafi, R Hughes, A DeSombre, ER AF Schwartz, JL Mustafi, R Hughes, A DeSombre, ER TI DNA and chromosome breaks induced by iodine-123-labeled estrogen in Chinese hamster ovary cells SO RADIATION RESEARCH LA English DT Article ID COLONY-FORMING ABILITY; MAMMALIAN-CELLS; CYTO-TOXICITY; HUMAN-LYMPHOCYTES; AUGER ELECTRONS; CANCER-CELLS; RECEPTOR; RADIOTOXICITY; RADIATION; DAMAGE AB The effects of the Auger electron-emitting isotope I-123, covalently bound to estrogen, on DNA single- and double-strand breakage and on chromosome breakage was determined in estrogen receptor-positive Chinese hamster ovary (CHO-ER) cells. Exposure to the I-123-labeled estrogen induced both single- and double-strand breaks with a ratio of single- to double-strand breaks of 2.8. The corresponding ratio with Co-60 gamma rays was 15.6. The dose response was biphasic, suggesting either that receptor sites are saturated at high doses, or that there is a nonrandom distribution of breaks induced by the I-123-labeled estrogen. The I-123-labeled estrogen treatment induced chromosome aberrations with an efficiency of about 1 aberration for each 1000 disintegrations per cell. This corresponds to the mean lethal dose of I-123-labeled estrogen for these cells, suggesting that the lethal event induced by the Auger electron emitter bound to estrogen is a chromosome aberration. Most of the chromosome-type aberrations were dicentrics and rings, suggesting that I-123-labeled estrogen-induced chromosome breaks are rejoined, The F ratio, the ratio of dicentrics to centric rings, was 5.8+/-1.7, which is similar to that seen with high-LET radiations. Our results suggest that I-123 bound to estrogen is an efficient clastogenic agent, the cytotoxic damage produced by I-123 bound to estrogen is very like damage induced by high-LET radiation, and the I-123 in the estrogen receptor-DNA complex is probably in proximity to the sugar-phosphate backbone of the DNA. (C) 1996 by Radiation Research Society. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. UNIV CHICAGO,DEPT RADIAT & CELLULAR ONCOL,CHICAGO,IL 60637. UNIV CHICAGO,BEN MAY INST,CHICAGO,IL 60637. NR 40 TC 6 Z9 7 U1 0 U2 0 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD AUG PY 1996 VL 146 IS 2 BP 151 EP 158 DI 10.2307/3579587 PG 8 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA VA384 UT WOS:A1996VA38400005 PM 8693065 ER PT J AU Ebbe, S Taylor, S Maurer, H Kullgren, B AF Ebbe, S Taylor, S Maurer, H Kullgren, B TI Uptake of indium-111-labeled platelets and indium-111 oxine by murine kidneys after total-body irradiation SO RADIATION RESEARCH LA English DT Article ID CULTURED ENDOTHELIAL-CELLS; RADIATION NEPHROPATHY; PROSTACYCLIN FORMATION; RABBIT PLATELETS; RELEASE; INJURY; ACID; INVITRO; PIG AB Radiation nephropathy is a well-known late manifestation of renal irradiation in human beings and experimental animals. Its pathogenesis is unclear, but vascular injury may play a role. Endotheliar cells have been demonstrated to manifest a variety of abnormalities within hours of exposure to radiation. In the present experiments mice were exposed to lethal doses of whole-body radiation, and the distribution of In-111-labeled platelets was evaluated during the first week after irradiation. The purpose was to determine if early abnormalities of endothelial cells would be manifested by altered sequestration of platelets in kidneys and other organs. It was found that the indium accumulated in the kidneys of irradiated mice to a greater extent than in nonirradiated mice, supporting the possibility of early vascular injury. In control experiments, administration of In-111-oxine was also followed by excessive accumulation of radioactivity in kidneys of irradiated mice, but the pattern of accumulation differed from that seen after injection of radiolabeled platelets. Renal hyperemia was not demonstrable with Cr-51-labeled red cells, renal vascular permeability was not detected with I-125-labeled albumin, and the pattern of renal uptake of plasma proteins labeled with Fe-59 or In-111 did not coincide with that seen from In-111 administered as labeled platelets or oxine. Renal uptake of In-111-oxine was not associated with alterations in urinary or fecal excretion or an increase in total-body retention of the radioisotope. The findings are consistent with the notion that renal vascular injury at the time of irradiation results in accumulation of platelets or platelet constituents during the first week after total-body irradiation of mice. (C) 1996 by Radiation Research Society. RP Ebbe, S (reprint author), LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 29 TC 7 Z9 7 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD AUG PY 1996 VL 146 IS 2 BP 216 EP 222 DI 10.2307/3579593 PG 7 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA VA384 UT WOS:A1996VA38400011 PM 8693071 ER PT J AU Wallen, SL Pfund, DM Fulton, JL Yonker, CR Newville, M Ma, YJ AF Wallen, SL Pfund, DM Fulton, JL Yonker, CR Newville, M Ma, YJ TI High-pressure, capillary x-ray absorption fine structure cell for studies of liquid and supercritical fluid solutions SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID XAFS AB A method is described to acquire x-ray absorption fine structure (XAFS) spectra of high-pressure liquid and supercritical fluid solutions. The technique employs a short length of fused-silica capillary tubing that has an inner diameter of 250 mu m and an outer diameter of 360 mu m. A hairpin bend is formed near the center of the capillary and the bend is then placed end-on directly in the focused x-ray beam. Fluorescence spectra were acquired in a 90 degrees geometry using a 13 element Ge detector. Demonstration XAFS spectra are reported for a Mn organometallic complex dissolved in subcritical and supercritical CO2. Although the maximum pressure of these studies was 160 bar, with slight modification, the method will be applicable to studies requiring pressures as high as 4 kbar. (C) 1996 American Institute of Physics. C1 PACIFIC NW LAB, ENVIRONM & ENERGY SCI DIV, RICHLAND, WA 99352 USA. UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. NR 7 TC 20 Z9 20 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 1996 VL 67 IS 8 BP 2843 EP 2845 DI 10.1063/1.1147115 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VC773 UT WOS:A1996VC77300027 ER PT J AU TonThat, DM Clarke, J AF TonThat, DM Clarke, J TI Direct current superconducting quantum interference device spectrometer for pulsed nuclear magnetic resonance and nuclear quadrupole resonance at frequencies up to 5 MHz SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID SQUID MAGNETOMETER; DC SQUID; FEEDBACK AB A spectrometer based on a de superconducting quantum interference device (SQUID) has been developed for the direct detection of nuclear magnetic resonance (NMR) or nuclear quadrupole resonance (NQR) at frequencies up to 5 MHz. The sample is coupled to the input coil of the niobium-based SQUID via a nonresonant superconducting circuit. The flux locked loop involves the direct offset integration technique with additional positive feedback in which the output of the SQUID is coupled directly to a low-noise preamplifier. Precession of the nuclear quadrupole spins is induced by a magnetic field pulse with the feedback circuit disabled; subsequently, flux locked operation is restored and the SQUID amplifies the signal produced by the nuclear free induction signal. The spectrometer has been used to detect Al-27 NQR signals in ruby (Al2O3[Cr3+]) at 359 and 714 kHz. (C) 1996 American Institute of Physics. C1 LAWRENCE LIVERMORE NATL LAB, DIV SCI MAT, BERKELEY, CA 94720 USA. RP TonThat, DM (reprint author), UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 16 TC 22 Z9 23 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 1996 VL 67 IS 8 BP 2890 EP 2893 DI 10.1063/1.1147122 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VC773 UT WOS:A1996VC77300036 ER PT J AU Baldwin, E AF Baldwin, E TI Emergency incident risk management - Kipp,JD, Loflin,ME SO RISK ANALYSIS LA English DT Book Review C1 OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN. RP Baldwin, E (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1996 VL 16 IS 4 BP 599 EP 599 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA VJ566 UT WOS:A1996VJ56600016 ER PT J AU Baldwin, E AF Baldwin, E TI Prudent practices in the laboratory - Natl-Res-Council SO RISK ANALYSIS LA English DT Book Review C1 OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN. RP Baldwin, E (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1996 VL 16 IS 4 BP 599 EP 599 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA VJ566 UT WOS:A1996VJ56600018 ER PT J AU Baldwin, E AF Baldwin, E TI Safety by objectives, 2nd edition - Peterson,D SO RISK ANALYSIS LA English DT Book Review C1 OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN. RP Baldwin, E (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1996 VL 16 IS 4 BP 599 EP 599 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA VJ566 UT WOS:A1996VJ56600017 ER PT J AU Baldwin, E AF Baldwin, E TI Foundations of rational choice under risk - Anand,P SO RISK ANALYSIS LA English DT Book Review C1 OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN. RP Baldwin, E (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1996 VL 16 IS 4 BP 599 EP 600 PG 2 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA VJ566 UT WOS:A1996VJ56600019 ER PT J AU Baldwin, E AF Baldwin, E TI The bloodborne pathogens standard - ONeal,JT SO RISK ANALYSIS LA English DT Book Review C1 OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN. RP Baldwin, E (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1996 VL 16 IS 4 BP 600 EP 600 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA VJ566 UT WOS:A1996VJ56600020 ER PT J AU Kim, WJ Sherby, OD Nieh, TG Frommeyer, G AF Kim, WJ Sherby, OD Nieh, TG Frommeyer, G TI Ingot-processed iron carbide (Fe-4.3wt%C) SO SCRIPTA MATERIALIA LA English DT Article ID SUPERPLASTIC BEHAVIOR C1 STANFORD UNIV, DEPT MAT SCI & ENGN, STANFORD, CA 94305 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. MAX PLANCK INST EISENFORSCH GMBH, D-40074 DUSSELDORF, GERMANY. RP Kim, WJ (reprint author), HONGIK UNIV, DEPT MET & SCI MAT, 72-1 SANGSU DONG, MAPO KU, SEOUL 121791, SOUTH KOREA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 10 TC 2 Z9 2 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD AUG 1 PY 1996 VL 35 IS 3 BP 299 EP 303 DI 10.1016/1359-6462(96)00151-0 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UU397 UT WOS:A1996UU39700001 ER PT J AU Kataoka, Y Perrin, J Hunter, N Milas, L Grdina, DJ AF Kataoka, Y Perrin, J Hunter, N Milas, L Grdina, DJ TI Antimutagenic effects of amifostine: Clinical implications SO SEMINARS IN ONCOLOGY LA English DT Article ID CHEMICAL RADIATION PROTECTORS; S-2-(3-AMINOPROPYLAMINO)-ETHYLPHOSPHOROTHIOIC ACID; S-2-(3-AMINOPROPYLAMINO)ETHYLPHOSPHOROTHIOIC ACID; RADIOPROTECTOR WR-2721; HODGKINS-DISEASE; NORMAL-TISSUES; V79 CELLS; WR-1065; MICE; DAMAGE C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. UNIV CHICAGO,DEPT RADIAT & CELLULAR ONCOL,CHICAGO,IL 60637. UNIV TEXAS,MD ANDERSON HOSP & TUMOR INST,HOUSTON,TX. NR 31 TC 37 Z9 37 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0093-7754 J9 SEMIN ONCOL JI Semin. Oncol. PD AUG PY 1996 VL 23 IS 4 SU 8 BP 53 EP 57 PG 5 WC Oncology SC Oncology GA VG260 UT WOS:A1996VG26000009 PM 8783668 ER PT J AU Sun, ZM AF Sun, ZM TI Reconstruction of source and medium parameters via wave-splitting and green function equations SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE inverse scattering; source; wave splitting; time dependent ID INVERSE SCATTERING; TIME DOMAIN; CYLINDER AB This paper apples the time-domain wave-splitting and the Green function concepts tu study two inverse problems involving an internal transient source embedded in a nondispersive inhomogeneous medium. These two inverse problems are (1) given the physical one-way travel time Green operator kernel (G) over bar(-) (0,t) and the source-space distribution function, reconstruct the wave-speed profile c(z) of the medium; (2) given the same kernel (G) over bar(-) (0,t) and the medium wave-speed function, recover tile source-space distribution profile p(z). Both numerical inversion algorithms and approximate-reconstruction formulas are presented. Several computational examples are given. RP Sun, ZM (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 19 TC 3 Z9 3 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PD AUG PY 1996 VL 56 IS 4 BP 1146 EP 1163 DI 10.1137/S0036139993250580 PG 18 WC Mathematics, Applied SC Mathematics GA UY321 UT WOS:A1996UY32100009 ER PT J AU Kim, JH AF Kim, JH TI Stochastic turning point problem in a one-dimensional refractive random multilayer SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE random medium; turning point; limit theorems ID ORDINARY DIFFERENTIAL EQUATIONS AB A one-dimensional model of random scattering is considered for a totally refracting random multilayer that has two separated spatial scales, i.e., deterministic macroscale and random microscale, The interplay of internal refraction and random multiple scattering for a turning point problem is analyzed with an intermediate scale of the wavelength. Two extended limit theorems for stochastic differential equations with a small parameter provide the characterization of the diffusion processes above and below the turning point, Both results are combined, and a global limit law for the phenomenon of the random phase is obtained. RP Kim, JH (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 13 TC 5 Z9 5 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PD AUG PY 1996 VL 56 IS 4 BP 1164 EP 1180 DI 10.1137/S0036139994277816 PG 17 WC Mathematics, Applied SC Mathematics GA UY321 UT WOS:A1996UY32100010 ER PT J AU Zhu, CY AF Zhu, CY TI Asymptotic convergence analysis of some inexact proximal point algorithms for minimization SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE proximal point algorithm; bundle method; convex minimization; linear convergence ID CONVEX MINIMIZATION AB In this paper, we prove that the inexact proximal point algorithm (FEA) in the form of Bonnans-Gilbert-Lemarechal-Sagastizabal's ''general algorithmic pattern'' (GAP-1) converges linearly under mild conditions. We also propose-another Variant (GAP-2) of inexact PPA that shares the same convergence property as GAP-1 but makes more sense numerically. Based on this essential result, we further prove the linear convergence for the outer iteration of the bundle method without requiring the differentiability of the objective function or the uniqueness of the solution. We also prove the linear convergence for the outer iteration of Correa-Lemarechal's ''implementable form'' of PPA and derive its rate. C1 ARGONNE NATL LAB,DIV COMP SCI,ARGONNE,IL 60439. NR 11 TC 5 Z9 5 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PD AUG PY 1996 VL 6 IS 3 BP 626 EP 637 DI 10.1137/S1052623494255923 PG 12 WC Mathematics, Applied SC Mathematics GA VC017 UT WOS:A1996VC01700006 ER PT J AU Winkler, JP Cherry, RS Schlesinger, WH AF Winkler, JP Cherry, RS Schlesinger, WH TI The Q(10) relationship of microbial respiration in a temperate forest soil SO SOIL BIOLOGY & BIOCHEMISTRY LA English DT Article ID CARBON; DECOMPOSITION; EVOLUTION; EMISSIONS; TURNOVER; STORAGE; FLUX AB Our objective was to study the effect of temperature on rates of soil respiration in the A-, E- and B-horizons of a temperate forest (Durham, North Carolina, USA). Soil samples were incubated for several months at 4, 15, 22 and 38 degrees C and respiration was measured frequently during incubation. For each soil horizon, rates of CO? evolution varied significantly with time of incubation and temperature. The A-horizon had the highest initial rates of soil respiration, followed by the B- and E-horizon soils for each temperature. The initial rates of respiration from the A-soil horizon increased with temperature in accordance with the Arrhenius equation. The Q(10) for the A horizon calculated from initial respiration rates varied from 1.9 to 1.7 over the temperature range of 4 degrees C to 28 degrees C. Generally rates of respiration decreased during the incubation, although the total fraction of carbon respired from the soil was small (<3%). Copyright (C) 1996 Elsevier Science Ltd C1 DUKE UNIV,DEPT BOT,DURHAM,NC 27708. DUKE UNIV,DEPT GEOL,DURHAM,NC 27708. IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. NR 28 TC 140 Z9 164 U1 1 U2 23 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-0717 J9 SOIL BIOL BIOCHEM JI Soil Biol. Biochem. PD AUG PY 1996 VL 28 IS 8 BP 1067 EP 1072 DI 10.1016/0038-0717(96)00076-4 PG 6 WC Soil Science SC Agriculture GA VK892 UT WOS:A1996VK89200012 ER PT J AU Ozer, N Rubin, MD Lampert, CM AF Ozer, N Rubin, MD Lampert, CM TI Optical and electrochemical characteristics of niobium oxide films prepared by sol-gel process and magnetron sputtering - A comparison SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE niobia; sol-gel deposition; DC magnetron sputtering; electrochromism; optical properties ID THIN-FILMS; ELECTROCHROMIC PROPERTIES; NB2O5 AB Electrochromic niobia (Nb2O5) coatings were prepared by the sol-gel-spin-coating and d.c. magnetron sputtering techniques. Parameters were investigated fbr the process fabrication of sol-gel spin coated Nb2O5 films exhibiting high coloration efficiency comparable with that d.c. magnetron sputtered niobia films. X-ray diffraction studies (XRD) showed that the sol-gel deposited and magnetron sputtered films heat treated at temperatures below:450 degrees C were amorphous, whereas those heat treated at higher temperatures were slightly crystalline. X-ray photoelectron spectroscopy (XPS) studies showed that the stoichiometry of the films was Nb2O5. The refractive index and electrochromic coloration were found to depend on the preparation technique. Both films showed low absorption and high transparency in the visible range. We found that the n, k values of the sol-gel deposited films to be lower than for the sputtered films. The n and k values were n=1.82 and k=3x10(-3), and n=2.28 and k=4x10(-3) at 530 nm for sol-gel deposited and sputtered films, respectively. The electrochemical behavior and structural changes were investigated in 1 M LiClO4/propylene carbonate solution. Using the electrochemical measurements and X-ray photoelectron spectroscopy, the probable electrode reaction with the lithiation and delithiation is Nb2O5+x Li++x e(-) <-> LixNb2O5. Cyclic voltametric (CV) measurements showed that both Nb2O5 films exhibits electrochemical reversibility beyond. 1200 cycles without change in performance. ''In situ'' optical measurement revealed that those films exhibit an electrochromic effect in the spectral range 300 < lambda < 2100 nm but remain unchanged in the infrared spectral range. The change in visible transmittance was 40% for 250 nm thick electrodes. Spectroelectrochemical measurements showed that spin coated films were essentially electrochromically equivalent to those prepared by d.c. magnetron sputter deposition. C1 LAWRENCE LIVERMORE NATL LAB,BLDG TECHNOL PROGRAM,BERKELEY,CA 94720. RP Ozer, N (reprint author), ISTANBUL UNIV,FAC SCI,DEPT PHYS,VEZNECILER,ISTANBUL,TURKEY. NR 17 TC 45 Z9 46 U1 6 U2 29 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 1 PY 1996 VL 40 IS 4 BP 285 EP 296 DI 10.1016/0927-0248(95)00147-6 PG 12 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA VA482 UT WOS:A1996VA48200001 ER PT J AU Eldridge, JE Xie, Y Schlueter, JA Williams, JM Naumann, D Roy, T AF Eldridge, JE Xie, Y Schlueter, JA Williams, JM Naumann, D Roy, T TI Infrared optical properties of the organic superconductor kappa(L)-(BEDT-TTF)(2)Cu(CF3)(4)center dot TCE (T-c=4K) SO SOLID STATE COMMUNICATIONS LA English DT Article DE organic crystals; optical properties; phenon; inelastic light scattering; light absorption and reflection ID ELECTRON-DONOR MOLECULE; TRANSITION; SALTS; TEMPERATURE; ANION; TC AB We present measurements of the polarized infrared reflectivity at 10 K from a single crystal of kappa(L)-(BEDT-TTF)(2)Cu(CF3)(4) . TCE, which is the first BEDT-TTF superconductor with an organometallic anion (T-c = 4 K). The resulting conductivity spectra are similar to those of the highest-T-c BEDT-TTF superconductors with polymeric anions such as (BEDT-TTF)(2)Cu[N(CN)(2)]Br, but show signs of the disorder which is present, and also show this compound to be less two-dimensional than (BEDT-TTF)(2)Cu[N(CN)(2)] Br. We have identified infrared and Raman features which are due to the vibrations of the CU(CF3)(4)(-) anion, and with the help of a small amount of group theory have assigned some of them to their symmetry species. Copyright (C) 1996 Elsevier Science Ltd C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. UNIV COLOGNE,INST ANORGAN CHEM,D-50939 COLOGNE,GERMANY. RP Eldridge, JE (reprint author), UNIV BRITISH COLUMBIA,DEPT PHYS,VANCOUVER,BC V6T 1Z1,CANADA. NR 17 TC 5 Z9 5 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD AUG PY 1996 VL 99 IS 5 BP 335 EP 340 DI 10.1016/0038-1098(96)00222-0 PG 6 WC Physics, Condensed Matter SC Physics GA UW871 UT WOS:A1996UW87100006 ER PT J AU Ying, ZC Wang, J Plummer, EW AF Ying, ZC Wang, J Plummer, EW TI Dynamics of the surface phase transformations in the K/Al(111) system SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium on Dynamical Quantum Processes on Solid Surfaces CY SEP 20-25, 1995 CL TOYONAKA, JAPAN DE alkali metal; aluminum; nonlinear optics; phase transformation; second harmonic generation; surface structure ID OPTICAL 2ND-HARMONIC GENERATION; METASTABLE ADSORPTION SITES; SIMPLE METALS; AL(111); RECONSTRUCTION; TRANSITION; IDENTIFICATION; CHEMISORPTION; DISORDER; NA AB Second harmonic generation has been used to study the dynamics of the phase transformations which occur for submonolayer films of potassium on the (111) face of aluminum. The second harmonic signal is very sensitive to the geometrical structure, symmetry, and electronic structure of the adsorbed layer. This system reveals an intricate phase diagram including two-dimensional condensation, co-existence regimes between a lattice gas and ordered islands, and order-preserving irreversible transformation. The latter transformation which occurs as a function of temperature shows a damped-oscillatory behavior. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,CHEM & BIOL PHYS SECT,OAK RIDGE,TN 37831. UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104. NR 28 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 1 PY 1996 VL 363 IS 1-3 BP 289 EP 295 DI 10.1016/0039-6028(96)00150-1 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA UZ624 UT WOS:A1996UZ62400041 ER PT J AU Waldfried, C McIlroy, DN Zhang, JD Dowben, PA Katrich, GA Plummer, EW AF Waldfried, C McIlroy, DN Zhang, JD Dowben, PA Katrich, GA Plummer, EW TI Determination of the surface Debye temperature of Mo(112) using valence band photoemission SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium on Dynamical Quantum Processes on Solid Surfaces CY SEP 20-25, 1995 CL TOYONAKA, JAPAN DE angle-resolved photoemission; low-energy electron diffraction; X-ray scattering, diffraction, and reflection ID ENERGY-ELECTRON-DIFFRACTION; ANGLE-RESOLVED-PHOTOEMISSION; ION-SCATTERING; STRUCTURAL-ANALYSIS; BI(111) SURFACE; LEED ANALYSIS; ANHARMONICITY; VIBRATIONS; CU(110); ADSORPTION AB The temperature dependence of the valence-band emission from the (112) surface of molybdenum has been studied with ultraviolet photoemission spectroscopy. Valence-band features arising from the bulk and surface states exhibit different temperature dependences. The results can be explained in terms of bulk and surface vibrational disorder. A surface (bulk) Debye temperature of 313 K (422 K) is extracted from the data. These numbers will be compared to surface Debye temperatures measured with different techniques and on other materials. The conclusion is that there are major inconsistencies in the reported ratio of the surface to bulk Debye temperature, presumably as a result of the approximations used to include thermal motion in the analysis. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. UNIV NEBRASKA,BEHLEN LAB PHYS,DEPT PHYS & ASTRON,LINCOLN,NE 68588. NATL ACAD SCI UKRAINE,INST PHYS,KIEV 252650,UKRAINE. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. NR 63 TC 46 Z9 47 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 1 PY 1996 VL 363 IS 1-3 BP 296 EP 302 DI 10.1016/0039-6028(96)00151-3 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA UZ624 UT WOS:A1996UZ62400042 ER PT J AU Burns, AR Stechel, EB Jennison, DR AF Burns, AR Stechel, EB Jennison, DR TI Aspects of electronically stimulated processes of chemisorbed molecules SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium on Dynamical Quantum Processes on Solid Surfaces CY SEP 20-25, 1995 CL TOYONAKA, JAPAN DE ammonia; density functional calculations; electron stimulated desorption (ESD); low index single crystal surfaces; molecular dynamics; nitrogen oxides; photon stimulated desorption; resonance enhanced multiphoton ionization mass spectroscopy (REMPI/MS) ID RESOLVED ANGULAR-DISTRIBUTIONS; POTENTIAL-ENERGY SURFACES; LASER-INDUCED DESORPTION; NEUTRAL PRODUCTS; PT(111); AMMONIA; DYNAMICS; NO; DISSOCIATION; CO AB We discuss recent insights into the dynamical nature of electron- and photon-stimulated surface processes for chemisorbed molecules. Much of what we have learned stems from the correlation of quantum-resolved data on the products with the nature of the excited state(s), the excitation lifetimes, and the multidimensional potential energy surfaces. The latter are particularly important when two or more degrees of freedom in the adsorbates determine the dynamics and yields. Rapid advances in local-density functional approximation calculations now allow us to characterize the multidimensional aspects of ground slate potential energy surfaces for chemisorbed molecules. RP Burns, AR (reprint author), SANDIA NATL LABS,MS 1413,ALBUQUERQUE,NM 87185, USA. RI Stechel, Ellen/B-1253-2012 NR 46 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 1 PY 1996 VL 363 IS 1-3 BP 303 EP 312 DI 10.1016/0039-6028(96)00152-5 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA UZ624 UT WOS:A1996UZ62400043 ER PT J AU Okada, M Baddorf, AP Zehner, DM Plummer, EW AF Okada, M Baddorf, AP Zehner, DM Plummer, EW TI Effects of hydrogen on the dynamics of the Mo0.95Re0.05(110) surface SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium on Dynamical Quantum Processes on Solid Surfaces CY SEP 20-25, 1995 CL TOYONAKA, JAPAN DE angle resolved photoemission; electron energy loss spectroscopy; hydrogen; low-energy electron diffraction (LEED); low-index single-crystal surfaces; molybdenum; rhenium ID PACKED METAL-SURFACES; W(110) SURFACE; COVERED W(110); SCATTERING; RECONSTRUCTION; MO(110) AB The effect of adsorbed H on the Mo0.95Re0.05(110) surface has been investigated. Results obtained from low-energy electron diffraction (LEED), high-resolution electron energy loss spectroscopy (HREELS) and angle-resolved ultraviolet photoemission spectroscopy (ARUPS) are presented. A (2 x 2) LEED pattern is observed for H coverages around theta similar to 0.5 ML and is attributed to reconstruction of the substrate. Ar higher coverages, a (1 x 1) pattern is observed. Two peaks are observed at loss energies of 99 and 153 meV in the HREELS spectra for the H-saturated Mo0.95Re0.05(110) surface consistent with a quasi-trigonal adsorption site. Both peaks show an isotopic shift, confirming that they are due to hydrogen vibrational modes. A two-dimensional Fermi surface was determined using ARUPS for the H-saturated Mo0.95Re0.05(110) surface. Fermi-surface nesting vectors were observed at the momentum predicted by theoretical calculations for H-saturated Mo(110) where a phonon anomaly is observed. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. RI Baddorf, Arthur/I-1308-2016 OI Baddorf, Arthur/0000-0001-7023-2382 NR 23 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 1 PY 1996 VL 363 IS 1-3 BP 416 EP 422 DI 10.1016/0039-6028(96)00170-7 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA UZ624 UT WOS:A1996UZ62400060 ER PT J AU Southworth, F AF Southworth, F TI Gravity models of spatial interaction behavior - Sen,A, Smith,TE SO TRANSPORTATION SCIENCE LA English DT Book Review RP Southworth, F (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 2 PU OPERATIONS RES SOC AMER PI BALTIMORE PA 1314 GUILFORD AVENUE BUSINESS OFFICE, BALTIMORE, MD 21202 SN 0041-1655 J9 TRANSPORT SCI JI Transp. Sci. PD AUG PY 1996 VL 30 IS 3 BP 270 EP 271 DI 10.1287/trsc.30.3.270 PG 2 WC Operations Research & Management Science; Transportation; Transportation Science & Technology SC Operations Research & Management Science; Transportation GA VG800 UT WOS:A1996VG80000007 ER PT J AU Sugg, DW Chesser, RK Dobson, FS Hoogland, JL AF Sugg, DW Chesser, RK Dobson, FS Hoogland, JL TI Population genetics meets behavioral ecology SO TRENDS IN ECOLOGY & EVOLUTION LA English DT Article ID MATING SYSTEMS; VARIABILITY; PHILOPATRY; DISPERSAL; DIVERSITY; MAMMALS; SIZES; FLOW AB Populations are often composed of more than just randomly mating subpopuations - many organisms form social groups with distinct patterns of mating and dispersal. Such patterns have received much attention in behavioral ecology, yet theories of population genetics rarely take social structures into account, Consequently, population geneticists often report high levels of apparent inbreeding and concomitantly low effective sizes, even for species that avoid mating between close kin. Recently, a view of gene dynamics has been introduced that takes dispersal and social structure into account. Accounting for social structure in population genetics leads to a different perspective on how genetic variation is partitioned and the rate at which genic diversity is lost in natural populations - a view that is more consistent with observed behaviors far the minimization of inbreeding. C1 UNIV GEORGIA,DEPT GENET,ATHENS,GA 30602. AUBURN UNIV,DEPT ZOOL & WILDLIFE SCI,AUBURN,AL 36849. UNIV MARYLAND,APPALACHIAN ENVIRONM LAB,FROSTBURG,MD 21532. RP Sugg, DW (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,DIV WILDLIFE ECOL & TOXICOL,AIKEN,SC 29802, USA. RI Hoogland, John/B-3950-2015 NR 34 TC 221 Z9 223 U1 2 U2 41 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0169-5347 J9 TRENDS ECOL EVOL JI Trends Ecol. Evol. PD AUG PY 1996 VL 11 IS 8 BP 338 EP 342 DI 10.1016/0169-5347(96)20050-3 PG 5 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA UX909 UT WOS:A1996UX90900017 PM 21237872 ER PT J AU McLaughlin, SB Wang, YC AF McLaughlin, SB Wang, YC TI Foliar phytochelatin levels as indicators of forest decline SO TRENDS IN PLANT SCIENCE LA English DT News Item ID SILENE-VULGARIS; ECOSYSTEMS; TOLERANCE; NUTRITION; ALUMINUM RP McLaughlin, SB (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37830, USA. NR 15 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 1360-1385 J9 TRENDS PLANT SCI JI Trends Plant Sci. PD AUG PY 1996 VL 1 IS 8 BP 249 EP 250 PG 2 WC Plant Sciences SC Plant Sciences GA VB149 UT WOS:A1996VB14900002 ER PT J AU Zhuang, X Shen, YR AF Zhuang, X Shen, YR TI The application of nonlinear optics to the study of polymers at interfaces SO TRENDS IN POLYMER SCIENCE LA English DT Review ID 2ND HARMONIC-GENERATION; SUM-FREQUENCY GENERATION; AIR-WATER-INTERFACE; 2ND-HARMONIC GENERATION; LIQUID-CRYSTAL; MOLECULAR MONOLAYERS; SURFACE; ALIGNMENT; SPECTROSCOPY; DYNAMICS AB Second-order nonlinear optical processes are forbidden in media with inversion symmetry but are allowed at surfaces and interfaces. They can therefore be used as a highly surface-specific tool for surface studies. Their many intrinsic advantages have made these surface techniques most powerful and versatile. This article shows how they can be applied to polymer interfaces with great success. C1 UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY NATL LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. NR 35 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-4793 J9 TRENDS POLYM SCI JI Trends Polym. Sci. PD AUG PY 1996 VL 4 IS 8 BP 258 EP 264 PG 7 WC Polymer Science SC Polymer Science GA VC528 UT WOS:A1996VC52800004 ER PT J AU Neelov, IM Lyulin, AV Torchinskii, FI Darinskii, AA Cooke, R AF Neelov, IM Lyulin, AV Torchinskii, FI Darinskii, AA Cooke, R TI Spectrum of relaxation times for the normal modes of deformed polymer chain: Numerical modeling SO VYSOKOMOLEKULYARNYE SOEDINENIYA SERIYA A & SERIYA B LA Russian DT Article ID BROWNIAN DYNAMICS; LOCAL DYNAMICS; FIELD; SIMULATION AB The local orientational chain mobility and the spectra of relaxation times were studied by methods of Brownian dynamics in a model polymer chain with retarded internal rotation, exposed in a strong external field of dipole symmetry. Variation of the orientational chain mobility with increasing field strength in this model is analogous to the pattern of mobility variation in a model of freely-jointed chain. The average amplitudes of rotation and the characteristic chain relaxation times decrease with increasing field strength, Elongation of the chain leads to splitting of the spectrum of relaxation times of the normal modes into the longitudinal and transverse components. In a dipole field, in contrast to the quadrupole field, these spectra vary in a qualitatively similar manner (albeit with some quantitative differences) with increasing field. Virtually all relaxation times of the normal modes (except for the most small-scale ones) decrease with increasing field strength. The main contribution to changes in the spectra of relaxation times is that due to variation of the equilibrium factors represented by the effective coefficients of elasticity of the normal modes. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Neelov, IM (reprint author), RUSSIAN ACAD SCI,INST MACROMOL CPDS,BOLSHOI PR 31,ST PETERSBURG 199004,RUSSIA. RI Neelov, Igor/M-5338-2014; Lyulin, Alexey/E-6704-2017; OI Neelov, Igor/0000-0002-5930-9892; Lyulin, Alexey/0000-0002-7533-3366; Неелов, Игорь/0000-0003-4187-6810 NR 21 TC 4 Z9 5 U1 0 U2 2 PU MEZHDUNARODNAYA KNIGA PI MOSCOW PA 39 DIMITROVA UL., 113095 MOSCOW, RUSSIA SN 0507-5475 J9 VYSOKOMOL SOEDIN JI Vysokomol. Soedin. PD AUG PY 1996 VL 38 IS 8 BP 1394 EP 1402 PG 9 WC Polymer Science SC Polymer Science GA VL486 UT WOS:A1996VL48600020 ER PT J AU Bogner, JE Sweeney, RE Coleman, D Huitric, R Ririe, GT AF Bogner, JE Sweeney, RE Coleman, D Huitric, R Ririe, GT TI Using isotopic and molecular data to model landfill gas processes SO WASTE MANAGEMENT & RESEARCH LA English DT Article DE landfill; landfill gas; stable isotopes; methane generation; methane oxidation; carbon dioxide; USA ID CARBON; METHANE; HYDROGEN; REFUSE AB Using a large data set, a preliminary investigation has been made to evaluate the usefulness of stable isotope ratios for improving our understanding of methane and carbon dioxide generation in landfills. Included are approximately 130 landfill gas samples from across the U.S.A., and 18 recent samples from: (1) an Argonne Laboratory study area in the Brea-Olinda Landfill, Orange County, California (U.S.A); and (2) several Los Angeles County landfills, California (U.S.A). The following isotope ratios were examined: delta(13)C for methane, delta(13)C for carbon dioxide and delta D for methane. Using simple ratio plots supplemented by mass-balance calculations, these data show promise for indicating the relative contributions of the four major carbon cycle processes in landfills, namely: (1) direct oxidation of organic material to carbon dioxide; (2) methane generation from fermentation (acetate cleavage); (3) methane generation from carbon dioxide reduction; and (4) methane oxidation to carbon dioxide by methanotrophic bacteria. Both the methane generation and oxidation reactions are central to an explanation of the trends discussed herein. The data also suggest that direct oxidation of organic matter in the refuse may be contributing to the observed isotopic ratios in some cases. The trends observed at the Brea-Olinda site were similar to trends using the large U.S. database, suggesting that isotopic techniques may be useful to better constrain carbon cycle processes common to all landfill settings. (C) 1996 ISWA RP Bogner, JE (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 16 TC 14 Z9 14 U1 0 U2 9 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0734-242X J9 WASTE MANAGE RES JI Waste Manage. Res. PD AUG PY 1996 VL 14 IS 4 BP 367 EP 376 DI 10.1006/wmre.1996.0037 PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VB041 UT WOS:A1996VB04100004 ER PT J AU Francois, O Gilmore, T Pinto, MJ Gorelick, SM AF Francois, O Gilmore, T Pinto, MJ Gorelick, SM TI A physically based model for air-lift pumping SO WATER RESOURCES RESEARCH LA English DT Article ID VERTICAL 2-PHASE FLOW; SLUG FLOW; AIRLIFT PUMPS; CHURN FLOW; BUBBLE; MOTION; TUBES; TRANSITION; PREDICTION; VELOCITY AB A predictive, physically based model for pumping water from a well using air injection (air-lift pumping) was developed for the range of flow rates that we explored in a series of laboratory experiments. The goal was to determine the air flow rate required to pump a specific flow rate of water in a given well, designed for in-well air stripping of volatile organic compounds from an aquifer. The model was validated against original laboratory data as well as data from the literature. A laboratory air-lift system was constructed that consisted of a 70-foot-long (21-m-long) pipe, 5.5 inches (14 cm) inside diameter, in which an air line of 1.3 inches (3.3 cm) outside diameter was placed with its bottom at different elevations above the base of the long pipe. Experiments were conducted for different levels of submergence, with water-pumping rates ranging from 5 to 79 gallons/min (0.32-4.4 L/s), and air flow ranging from 7 to 38 standard cubic feet/min (0.2-1.1 m(3) STP/min). The theoretical approach adopted in the model was based on an analysis of the system as a one-dimensional two-phase flow problem. The expression for the pressure gradient includes inertial energy terms, friction, and gas expansion versus elevation. Data analysis revealed that application of the usual drift-flux model to estimate the air void fraction is not adequate for the observed flow patterns: either slug or churn flow. We propose a modified drift-flux model that accurately predicts air-lift pumping requirements for a range of conditions representative of in-well air-stripping operations. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Francois, O (reprint author), STANFORD UNIV, DEPT GEOG & ENVIRONM SCI, STANFORD, CA 94305 USA. NR 47 TC 4 Z9 5 U1 2 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD AUG PY 1996 VL 32 IS 8 BP 2383 EP 2399 DI 10.1029/96WR00899 PG 17 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA VA834 UT WOS:A1996VA83400005 ER PT J AU Warren, TL Krajcinovic, D AF Warren, TL Krajcinovic, D TI Random Cantor set models for the elastic perfectly plastic contact of rough surfaces SO WEAR LA English DT Article DE cantor set; contact of rough surfaces; fractal representation ID FRACTAL DIMENSION AB The objective of this study was to formulate discrete and continuous spatial models to describe the elastic-perfectly plastic deformation of two rough surfaces in contact. The two surfaces in contact are assumed to exhibit fractal behavior and are modeled as an effective fractal surface compressed into a smooth rigid substrate. The rough self-affine fractal structure of the effective surface is approximated by a random Canter set representation embedded in two dimensions. Both of the proposed models admit analytical solutions whether the plastic deformation is volume conserving or not. Presented results illustrate the effects that volume conservation and initial surface structure have on the elastic-perfectly plastic deformation process. The results from the continuous model are compared with the results obtained from the discrete model, and existing experimental load displacement data for the deformation of a bead-blasted steel surface. C1 ARIZONA STATE UNIV,DEPT MECH & AEROSP ENGN,TEMPE,AZ 85287. RP Warren, TL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 29 TC 44 Z9 52 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD AUG PY 1996 VL 196 IS 1-2 BP 1 EP 15 DI 10.1016/0043-1648(95)06785-X PG 15 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA VB353 UT WOS:A1996VB35300001 ER PT J AU Kleinke, H Franzen, HF AF Kleinke, H Franzen, HF TI HfNixP - Intercalation of Ni into the three-dimensional compound NfP SO ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE LA English DT Article DE hafnium nickel phosphide; HfNixP; metal-rich phosphide; intercalation; crystal structure; electronic structure ID CRYSTAL-STRUCTURE AB The new compound HfNixP (x = 0.426(1), crystal structure. P6(3)/mmc, a = 3.737(1) Angstrom, c = 12.666(2) Angstrom, V = 153.21(7) Angstrom(3)) has been prepared by are-melting of HfP with nickel and subsequent annealing at 1400 degrees C. Its crystal structure can be considered as a filled HfP structure, with the Ni atoms inserted into the trigonal prismatic voids of the Hi sublattice. Since the neighboring trigonal Hf-6 prisms are centered by P atoms, each of the three rectangular Faces of the Hf6Ni prism is capped with one P atom. Altogether, the structure of HfNixP consists of alternating layers of Hf atoms with the packing sequence AABB. One P and the Ni position are situated between the eclipsed Hf layers, whereas the other P site between the A and B layers is surrounded by six Hf atoms in a staggered arrangement. The calculated density of states (Extended Huckel approximation) points to metallic conductivity; threedimensional metallic behavior is assumed because of the Hf-Hf bonding interactions along all three directions. RP Kleinke, H (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 41 TC 10 Z9 10 U1 0 U2 5 PU JOHANN AMBROSIUS BARTH VERLAG PI HEIDELBERG PA IM WEIHER 10, D-69121 HEIDELBERG, GERMANY SN 0044-2313 J9 Z ANORG ALLG CHEM JI Z. Anorg. Allg. Chem. PD AUG PY 1996 VL 622 IS 8 BP 1342 EP 1348 DI 10.1002/zaac.19966220812 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VD172 UT WOS:A1996VD17200011 ER PT J AU Toth, KS Batchelder, JC Moltz, DM Robertson, JD AF Toth, KS Batchelder, JC Moltz, DM Robertson, JD TI Identification of Pb-180 SO ZEITSCHRIFT FUR PHYSIK A-HADRONS AND NUCLEI LA English DT Article AB The alpha decay of the new isotope Pb-180 was observed in Ca-40 bombardments of Sm-144: E(alpha) = 7.23(4) MeV, and, T-1/2 = (4(-2)(+4)) ms. With this decay energy and the known mass of Hg-176, the mass excess of Pb-180 was calculated to be -1.98(5) MeV. C1 LOUISIANA STATE UNIV,BATON ROUGE,LA 70803. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV KENTUCKY,LEXINGTON,KY 40506. RP Toth, KS (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 10 TC 13 Z9 13 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0939-7922 J9 Z PHYS A-HADRON NUCL JI Z. Phys. A.-Hadrons Nuclei PD AUG PY 1996 VL 355 IS 3 BP 225 EP 226 DI 10.1007/s002180050103 PG 2 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA VC433 UT WOS:A1996VC43300003 ER PT J AU Wells, BO Birgeneau, RJ Chou, FC Endoh, Y Johnston, DC Kastner, MA Lee, YS Shirane, G Tranquada, JM Yamada, K AF Wells, BO Birgeneau, RJ Chou, FC Endoh, Y Johnston, DC Kastner, MA Lee, YS Shirane, G Tranquada, JM Yamada, K TI Intercalation and staging behavior in super-oxygenated La2CuO4+delta SO ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER LA English DT Article ID NEUTRON-DIFFRACTION; PHASE-SEPARATION; SUPERCONDUCTING LA2CUO4+DELTA; ELECTROCHEMICAL OXIDATION; CRYSTAL-STRUCTURE; LA2NIO4+DELTA; LA2CUO4.032; DELTA AB A high temperature electrochemical oxidation process has been used to produce large single crystals of La2CuO4+delta suitable for neutron scattering experiments. Below room temperature the oxygen-rich phases have structural superlattice scattering peaks which indicate new periodicities ranging from 2 to 6.6 layers perpendicular to the copper oxide planes. A model structure originally proposed for La2NiO4+delta can account for the superlattice peaks as a result of anti-phase domain boundaries between different tilt directions of the CuO6 octahedra. Within this model, the changes in CuO6 tilt directions are induced by segregated layers of interstitial oxygen which order in a manner similar to intercalants in graphite. This structural model thus clarifies previous work and establishes La2CuO4+delta as a unique Lamellar superconducting system with annealed disorder. C1 MIT, CTR MAT SCI & ENGN, CAMBRIDGE, MA 02139 USA. TOHOKU UNIV, DEPT PHYS, AOBA KU, SENDAI, MIYAGI 98077, JAPAN. IOWA STATE UNIV, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV, DEPT PHYS & ASTRON, AMES, IA 50011 USA. BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. RP Wells, BO (reprint author), MIT, DEPT PHYS, CAMBRIDGE, MA 02139 USA. RI Tranquada, John/A-9832-2009; Yamada, Kazuyoshi/C-2728-2009 OI Tranquada, John/0000-0003-4984-8857; NR 29 TC 69 Z9 69 U1 2 U2 12 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0722-3277 J9 Z PHYS B CON MAT JI Z. Phys. B-Condens. Mat. PD AUG PY 1996 VL 100 IS 4 BP 535 EP 545 DI 10.1007/s002570050158 PG 11 WC Physics, Condensed Matter SC Physics GA UY901 UT WOS:A1996UY90100008 ER PT J AU Abreu, P Adam, W Adye, T Agasi, E Ajinenko, I Aleksan, R Alekseev, GD Alemany, R Allport, PP Almehed, S Amaldi, U Amato, S Andreazza, A Andrieux, ML Antilogus, P Apel, WD Arnoud, Y Asman, B Augustin, JE Augustinus, A Baillon, P Bambade, P Barao, F Barate, R Barbi, M Barbiellini, G Bardin, DY Baroncelli, A Barring, O Barrio, JA Bartl, W Bates, MJ Battaglia, M Baubillier, M Baudot, J Becks, KH Begalli, M Beilliere, P Belokopytov, Y Benvenuti, AC Berggren, M Bertrand, D Bianchi, F Bigi, M Bilenky, MS Billoir, P Bloch, D Blume, M Blyth, S Bolognese, T Bonesini, M Bonivento, W Booth, PSL Borisov, G Bosio, C Bosworth, S Botner, O Boudinov, E Bouquet, B Bourdarios, C Bowcock, TJV Bozzo, M Branchini, P Brand, KD Brenke, T Brenner, RA Bricman, C Brillault, L Brown, RCA Bruckman, P Brunet, JM Bugge, L Buran, T Burgsmueller, T Buschmann, P Buys, A Cabrera, S Caccia, M Calvi, M Rozas, AJC Camporesi, T Canale, V Canepa, M Cankocak, K Cao, F Carena, F Carroll, L Caso, C Gimenez, MVC Cattai, A Cavallo, FR Cerrito, L Chabaud, V Chapkin, M Charpentier, P Chaussard, L Chauveau, J Checchia, P Chelkov, GA Chen, M Chierici, R Chliapnikov, P Chochula, P Chorowicz, V Chudoba, J Cindro, V Collins, P Contreras, JL Contri, R Cortina, E Cosme, G Cossutti, F Crawley, HB Crennell, D Crosetti, G Maestro, JC Czellar, S DahlJensen, E Dahm, J Dalmagne, B Dam, M Damgaard, G Dauncey, PD Davenport, M DaSilva, W Defoix, C Deghorain, A DellaRicca, G Delpierre, P Demaria, N DeAngelis, A DeBoer, W DeBrabandere, S DeClercq, C DeLaVaissiere, C DeLotto, B DeMin, A DePaula, L DeSaintJean, C Dijkstra, H DiCiaccio, L Djama, F Dolbeau, J Donszelmann, M Doroba, K Dracos, M Drees, J Drees, KA Dris, M Dufour, Y Edsall, D Ehret, R Eigen, G Ekelof, T Ekspong, G Elsing, M Engel, JP Ershaidat, N Erzen, B Santo, ME Falk, E Fassouliotis, D Feindt, M Fenyuk, A Ferrer, A Filippas, TA Firestone, A Fischer, PA Foeth, H Fokitis, E Fontanelli, F Formenti, F Franek, B Frenkiel, P Fries, DC Frodesen, AG Fruhwirth, R FuldaQuenzer, F Fuster, J Galloni, A Gamba, D Gandelman, M Garcia, C Garcia, J Gaspar, C Gasparini, U Gavillet, P Gazis, EN Gele, D Gerber, JP Gibbs, M Gokieli, R Golob, B Gopal, G Gorn, L Gorski, M Gouz, Y Gracco, V Graziani, E Grosdidier, G Grzelak, K Gumenyuk, S Gunnarsson, P Gunther, M Guy, J Hahn, F Hahn, S Hajduk, Z Hallgren, A Hamacher, K Hao, W Harris, FJ Hedberg, V Henriques, R Hernandez, JJ Herquet, P Herr, H Hessing, TL Higon, E Hilke, HJ Hill, TS Holmgren, SO Holt, PJ Holthuizen, D Hoorelbeke, S Houlden, M Hrubec, J Huet, K Hultqvist, K Jackson, JN Jacobsson, R Jalocha, P Janik, R Jarlskog, C Jarlskog, G Jarry, P JeanMarie, B Johansson, EK Jonsson, L Jonsson, P Joram, C Juillot, P Kaiser, M Kapusta, F Karafasoulis, K Karlson, M Karvelas, E Katsanevas, S Katsoufis, EC Keranen, R Khokhlov, Y Khomenko, BA Khovanski, NN King, B Kjaer, NJ Klein, H Klovning, A Kluit, P Koene, B Kokkinias, P Koratzinos, M Korcyl, K Kourkoumelis, C Kouznetsov, O Kramer, PH Krammer, M Kreuter, C Kronkvist, I Krumstein, Z Krupinski, W Kubinec, P Kucewicz, W Kurvinen, K Lacasta, C Laktineh, I Lamblot, S Lamsa, JW Lanceri, L Lane, DW Langefeld, P Last, I Laugier, JP Lauhakangas, R Leder, G Ledroit, F Lefebure, V Legan, CK Leitner, R Lemoigne, Y Lemonne, J Lenzen, G Lepeltier, V Lesiak, T Liko, D Lindner, R Lipniacka, A Lippi, I Loerstad, B Liken, JG Lopez, JM Loukas, D Lutz, P Lyons, L Maehlum, G Maio, A Malychev, V Mandl, F Marco, J Marco, R Marechal, B Margoni, M Marin, JC Mariotti, C Markou, A Maron, T MartinezRivero, C MartinezVidal, F Garcia, SMI Masik, J Matorras, F Matteuzzi, C Matthiae, G Mazzucato, M McCubbin, M McKay, R McNulty, R Medbo, J Merk, M Meroni, C Meyer, S Meyer, WT Michelotto, M Migliore, E Mirabito, L Mitaroff, WA Mjoernmark, U Moa, T Moeller, R Moenig, K Monge, MR Morettini, P Mueller, H Mundim, LM Murray, WJ Muryn, B Myatt, G Naraghi, F Navarria, FL Navas, S Nawrocki, K Negri, P Nemecek, S Neumann, W Neumeister, N Nicolaidou, R Nielsen, BS Nieuwenhuizer, M Nikolaenko, V Niss, P Nomerotski, A Normand, A Novak, M OberschulteBeckmann, W Obraztsov, V Olshevski, AG Onofre, A Orava, R Osterberg, K Ouraou, A Paganini, P Paganoni, M Pages, P Palka, H Papadopoulou, TD Papageorgiou, K Pape, L Parkes, C Parodi, F Passeri, A Pegoraro, M Peralta, L Pemegger, H Pernicka, M Perrotta, A Petridou, C Petrolini, A Petrovyck, M Phillips, HT Piana, G Pierre, F Pimenta, M Pindo, M Plaszcyzynski, S Podoborin, O Pol, ME Polok, G Poropat, P Pozdniakov, V Prest, M Privitera, P Pukhaeva, N Pullia, A Radojicic, D Ragazzi, S Rahman, H Ratoff, PN Read, AL Reale, M Rebecchi, P Redaelli, NG Regler, M Reid, D Benton, PB Resvanis, LK Richard, F Richardson, J Ridky, J Rinaudo, G Ripp, I Romero, A Roncagliolo, I Ronchese, P Roos, L Rosenberg, EI Rosso, E Roudeau, P Rovelli, T Ruckstuhl, W RuhlmannKleider, V Ruiz, A Rybicki, K Saarikko, H Sacquin, Y Sadovsky, A Sajot, G Salt, J Sanchez, J Sannino, M Schimmelpfennig, M Schneider, H Schwickerath, U Schyns, MAE Sciolla, G Scuri, F Seager, P Sedykh, Y Segar, AM Seitz, A Sekulin, R Shellard, RC Siccama, I Siegrist, P Simonetti, S Simonetto, F Sisakian, AN Sitar, B Skaali, TB Smadja, G Smirnov, N Smirnova, O Smith, GR Solovianov, O Sosnowski, R SouzaSantos, D Spassov, T Spiriti, E Sponholz, P Squarcia, S Stanescu, C Stapnes, S Stavitski, I Stichelbaut, F Stocchi, A Strauss, J Strub, R Stugu, B Szczekowski, M Szeptycka, M Tabarelli, T Tavernet, JP Tchikilev, O Tilquin, A Timmermans, J Tkatchev, LG Todorov, T Toet, DZ Tomaradze, A Tonazzo, A Tortora, L Transtromer, G Treille, D Trischuk, W Tristram, G Trombini, A Troncon, C Tsirou, A Turluer, ML Tyapkin, IA Tyndel, M Tzamarias, S Ueberschaer, B Ullaland, O Uvarov, V Valenti, G Vallazza, E VanderVelde, C VanApeldoorn, GW VanDam, P VanDoninck, WK VanEldik, J Vassilopoulos, N Vegni, G Ventura, L Venus, W Verbeure, F Verlato, M Vertogradov, LS Vilanova, D Vincent, P Vitale, L Vlasov, E Vodopyanov, AS Vrba, V Wahlen, H Walck, C Weierstall, M Weilhammer, P Weiser, C Wetherell, AM Wicke, D Wickens, JH Wielers, M Wilkinson, GR Williams, WSC Winter, M Witek, M Woschnagg, K Yip, K Yushchenko, O Zach, F Zaitsev, A Zalewska, A Zalewska, P Zavrtanik, D Zevgolatakos, E Zimin, NI Zito, M Zontar, D Zuberi, R Zucchelli, GC Zumerle, G AF Abreu, P Adam, W Adye, T Agasi, E Ajinenko, I Aleksan, R Alekseev, GD Alemany, R Allport, PP Almehed, S Amaldi, U Amato, S Andreazza, A Andrieux, ML Antilogus, P Apel, WD Arnoud, Y Asman, B Augustin, JE Augustinus, A Baillon, P Bambade, P Barao, F Barate, R Barbi, M Barbiellini, G Bardin, DY Baroncelli, A Barring, O Barrio, JA Bartl, W Bates, MJ Battaglia, M Baubillier, M Baudot, J Becks, KH Begalli, M Beilliere, P Belokopytov, Y Benvenuti, AC Berggren, M Bertrand, D Bianchi, F Bigi, M Bilenky, MS Billoir, P Bloch, D Blume, M Blyth, S Bolognese, T Bonesini, M Bonivento, W Booth, PSL Borisov, G Bosio, C Bosworth, S Botner, O Boudinov, E Bouquet, B Bourdarios, C Bowcock, TJV Bozzo, M Branchini, P Brand, KD Brenke, T Brenner, RA Bricman, C Brillault, L Brown, RCA Bruckman, P Brunet, JM Bugge, L Buran, T Burgsmueller, T Buschmann, P Buys, A Cabrera, S Caccia, M Calvi, M Rozas, AJC Camporesi, T Canale, V Canepa, M Cankocak, K Cao, F Carena, F Carroll, L Caso, C Gimenez, MVC Cattai, A Cavallo, FR Cerrito, L Chabaud, V Chapkin, M Charpentier, P Chaussard, L Chauveau, J Checchia, P Chelkov, GA Chen, M Chierici, R Chliapnikov, P Chochula, P Chorowicz, V Chudoba, J Cindro, V Collins, P Contreras, JL Contri, R Cortina, E Cosme, G Cossutti, F Crawley, HB Crennell, D Crosetti, G Maestro, JC Czellar, S DahlJensen, E Dahm, J Dalmagne, B Dam, M Damgaard, G Dauncey, PD Davenport, M DaSilva, W Defoix, C Deghorain, A DellaRicca, G Delpierre, P Demaria, N DeAngelis, A DeBoer, W DeBrabandere, S DeClercq, C DeLaVaissiere, C DeLotto, B DeMin, A DePaula, L DeSaintJean, C Dijkstra, H DiCiaccio, L Djama, F Dolbeau, J Donszelmann, M Doroba, K Dracos, M Drees, J Drees, KA Dris, M Dufour, Y Edsall, D Ehret, R Eigen, G Ekelof, T Ekspong, G Elsing, M Engel, JP Ershaidat, N Erzen, B Santo, ME Falk, E Fassouliotis, D Feindt, M Fenyuk, A Ferrer, A Filippas, TA Firestone, A Fischer, PA Foeth, H Fokitis, E Fontanelli, F Formenti, F Franek, B Frenkiel, P Fries, DC Frodesen, AG Fruhwirth, R FuldaQuenzer, F Fuster, J Galloni, A Gamba, D Gandelman, M Garcia, C Garcia, J Gaspar, C Gasparini, U Gavillet, P Gazis, EN Gele, D Gerber, JP Gibbs, M Gokieli, R Golob, B Gopal, G Gorn, L Gorski, M Gouz, Y Gracco, V Graziani, E Grosdidier, G Grzelak, K Gumenyuk, S Gunnarsson, P Gunther, M Guy, J Hahn, F Hahn, S Hajduk, Z Hallgren, A Hamacher, K Hao, W Harris, FJ Hedberg, V Henriques, R Hernandez, JJ Herquet, P Herr, H Hessing, TL Higon, E Hilke, HJ Hill, TS Holmgren, SO Holt, PJ Holthuizen, D Hoorelbeke, S Houlden, M Hrubec, J Huet, K Hultqvist, K Jackson, JN Jacobsson, R Jalocha, P Janik, R Jarlskog, C Jarlskog, G Jarry, P JeanMarie, B Johansson, EK Jonsson, L Jonsson, P Joram, C Juillot, P Kaiser, M Kapusta, F Karafasoulis, K Karlson, M Karvelas, E Katsanevas, S Katsoufis, EC Keranen, R Khokhlov, Y Khomenko, BA Khovanski, NN King, B Kjaer, NJ Klein, H Klovning, A Kluit, P Koene, B Kokkinias, P Koratzinos, M Korcyl, K Kourkoumelis, C Kouznetsov, O Kramer, PH Krammer, M Kreuter, C Kronkvist, I Krumstein, Z Krupinski, W Kubinec, P Kucewicz, W Kurvinen, K Lacasta, C Laktineh, I Lamblot, S Lamsa, JW Lanceri, L Lane, DW Langefeld, P Last, I Laugier, JP Lauhakangas, R Leder, G Ledroit, F Lefebure, V Legan, CK Leitner, R Lemoigne, Y Lemonne, J Lenzen, G Lepeltier, V Lesiak, T Liko, D Lindner, R Lipniacka, A Lippi, I Loerstad, B Liken, JG Lopez, JM Loukas, D Lutz, P Lyons, L Maehlum, G Maio, A Malychev, V Mandl, F Marco, J Marco, R Marechal, B Margoni, M Marin, JC Mariotti, C Markou, A Maron, T MartinezRivero, C MartinezVidal, F Garcia, SMI Masik, J Matorras, F Matteuzzi, C Matthiae, G Mazzucato, M McCubbin, M McKay, R McNulty, R Medbo, J Merk, M Meroni, C Meyer, S Meyer, WT Michelotto, M Migliore, E Mirabito, L Mitaroff, WA Mjoernmark, U Moa, T Moeller, R Moenig, K Monge, MR Morettini, P Mueller, H Mundim, LM Murray, WJ Muryn, B Myatt, G Naraghi, F Navarria, FL Navas, S Nawrocki, K Negri, P Nemecek, S Neumann, W Neumeister, N Nicolaidou, R Nielsen, BS Nieuwenhuizer, M Nikolaenko, V Niss, P Nomerotski, A Normand, A Novak, M OberschulteBeckmann, W Obraztsov, V Olshevski, AG Onofre, A Orava, R Osterberg, K Ouraou, A Paganini, P Paganoni, M Pages, P Palka, H Papadopoulou, TD Papageorgiou, K Pape, L Parkes, C Parodi, F Passeri, A Pegoraro, M Peralta, L Pemegger, H Pernicka, M Perrotta, A Petridou, C Petrolini, A Petrovyck, M Phillips, HT Piana, G Pierre, F Pimenta, M Pindo, M Plaszcyzynski, S Podoborin, O Pol, ME Polok, G Poropat, P Pozdniakov, V Prest, M Privitera, P Pukhaeva, N Pullia, A Radojicic, D Ragazzi, S Rahman, H Ratoff, PN Read, AL Reale, M Rebecchi, P Redaelli, NG Regler, M Reid, D Benton, PB Resvanis, LK Richard, F Richardson, J Ridky, J Rinaudo, G Ripp, I Romero, A Roncagliolo, I Ronchese, P Roos, L Rosenberg, EI Rosso, E Roudeau, P Rovelli, T Ruckstuhl, W RuhlmannKleider, V Ruiz, A Rybicki, K Saarikko, H Sacquin, Y Sadovsky, A Sajot, G Salt, J Sanchez, J Sannino, M Schimmelpfennig, M Schneider, H Schwickerath, U Schyns, MAE Sciolla, G Scuri, F Seager, P Sedykh, Y Segar, AM Seitz, A Sekulin, R Shellard, RC Siccama, I Siegrist, P Simonetti, S Simonetto, F Sisakian, AN Sitar, B Skaali, TB Smadja, G Smirnov, N Smirnova, O Smith, GR Solovianov, O Sosnowski, R SouzaSantos, D Spassov, T Spiriti, E Sponholz, P Squarcia, S Stanescu, C Stapnes, S Stavitski, I Stichelbaut, F Stocchi, A Strauss, J Strub, R Stugu, B Szczekowski, M Szeptycka, M Tabarelli, T Tavernet, JP Tchikilev, O Tilquin, A Timmermans, J Tkatchev, LG Todorov, T Toet, DZ Tomaradze, A Tonazzo, A Tortora, L Transtromer, G Treille, D Trischuk, W Tristram, G Trombini, A Troncon, C Tsirou, A Turluer, ML Tyapkin, IA Tyndel, M Tzamarias, S Ueberschaer, B Ullaland, O Uvarov, V Valenti, G Vallazza, E VanderVelde, C VanApeldoorn, GW VanDam, P VanDoninck, WK VanEldik, J Vassilopoulos, N Vegni, G Ventura, L Venus, W Verbeure, F Verlato, M Vertogradov, LS Vilanova, D Vincent, P Vitale, L Vlasov, E Vodopyanov, AS Vrba, V Wahlen, H Walck, C Weierstall, M Weilhammer, P Weiser, C Wetherell, AM Wicke, D Wickens, JH Wielers, M Wilkinson, GR Williams, WSC Winter, M Witek, M Woschnagg, K Yip, K Yushchenko, O Zach, F Zaitsev, A Zalewska, A Zalewska, P Zavrtanik, D Zevgolatakos, E Zimin, NI Zito, M Zontar, D Zuberi, R Zucchelli, GC Zumerle, G TI Determination of vertical bar V-cb vertical bar from the semileptonic decay B-0->D*(-)l(+)nu SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID QUARK EFFECTIVE THEORY; LUND MONTE-CARLO; JET FRAGMENTATION; E+E-PHYSICS; HEAVY; UPDATE AB Semileptonic decays B --> D*(-)l(+)nu X were selected from a sample of 3.1 million hadronic Z decays collected by the DELPHI detector at LEP. A topological search for semileptonic B decays to resonant and non-resonant D*(-)pi(+) states was performed and the ratio of the branching fractions: Br(B --> D*(-)l(+)nu X)/Br(B --> D*(-)l(+)nu X) + Br(B-0 --> D*(-)l(+)nu) = 0.19 +/- 0.10(stat) +/- 0.06(syst) was determined. Taking into account this contribution, the differential decay width of B-0 --> D*(-)l(+)nu was measured as a function of the momentum transfer from the B to the D*(-) in two separate analyses, using exclusive and inclusive methods of D*(-) reconstruction. The distributions were fitted over the full momentum transfer range to extract the product of /V-cb/ times the normalization of the decay form factor F(q(max)(2)): F(q(max)(2))/V-cb/ = (35.4 +/- 1.9(stat) +/- 2.4(syst)) . 10(-3). The value of /V-cb/ was computed using theoretical calculations of F(q(max?2), giving: /V-cb/ = (38.9 +/- 2.0(stat) +/- 2.6(syst) +/- 1.7(theory)) . 10(-3). The total branching fraction Br(B-0 --> D*(-)l(-)nu) was determined to be: Br(B-0 --> D*(-)l(+)nu) = (5.52 +/- 0.17(stat) +/- 0.68(syst))%. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. UNIV INSTELLING ANTWERP,DEPT PHYS,B-2610 WILRIJK,BELGIUM. FREE UNIV BRUSSELS,ULB,IIHE,B-1050 BRUSSELS,BELGIUM. UNIV MONS,FAC SCI,B-7000 MONS,BELGIUM. UNIV ATHENS,PHYS LAB,GR-10680 ATHENS,GREECE. UNIV BERGEN,DEPT PHYS,N-5007 BERGEN,NORWAY. UNIV BOLOGNA,DIPARTIMENTO FIS,I-40126 BOLOGNA,ITALY. IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. CTR BRASILEIRO PESQUISAS FIS,RJ-22290 RIO JANEIRO,BRAZIL. PONTIFICIA UNIV CATOLICA RIO DE JANEIRO,DEPT FIS,BR-22453 RIO JANEIRO,BRAZIL. UNIV ESTADUAL RIO DE JANEIRO,INST FIS,RIO JANEIRO,RJ,BRAZIL. COMENIUS UNIV BRATISLAVA,FAC MATH & PHYS,SK-84215 BRATISLAVA,SLOVAKIA. COLL FRANCE,PHYS CORPUSCULAIRE LAB,IN2P3 CNRS,F-75231 PARIS 05,FRANCE. CERN,CH-1211 GENEVA,SWITZERLAND. UNIV STRASBOURG 1,CTR RECH NUCL,IN2P3 CNRS,F-67037 STRASBOURG,FRANCE. DEMOKRITOS NATL CTR SCI RES,INST NUCL PHYS,GR-15310 ATHENS,GREECE. FZU,CAS,INST PHYS,DIV HIGH ENERGY PHYS,PRAGUE 18040 8,CZECH REPUBLIC. UNIV GENOA,DIPARTIMENTO FIS,I-16146 GENOA,ITALY. IST NAZL FIS NUCL,I-16146 GENOA,ITALY. UNIV GRENOBLE 1,INST NUCL SCI,IN2P3 CNRS,F-38026 GRENOBLE,FRANCE. SEFT,RES INST HIGH ENERGY PHYS,FIN-00014 HELSINKI,FINLAND. JOINT INST NUCL RES,DUBNA 101000,RUSSIA. UNIV KARLSRUHE,INST EXPT KERNPHYS,D-76128 KARLSRUHE,GERMANY. INST NUCL PHYS,PL-30055 KRAKOW,POLAND. UNIV MIN & MET KRAKOW,PL-30055 KRAKOW,POLAND. UNIV PARIS 11,ACCELERATEUR LINEAIRE LAB,IN2P3 CNRS,F-91405 ORSAY,FRANCE. UNIV LANCASTER,SCH PHYS & MAT,LANCASTER LA1 4YB,ENGLAND. FCUL,IST,LIP,P-1000 LISBON,PORTUGAL. UNIV LIVERPOOL,DEPT PHYS,LIVERPOOL L69 3BX,MERSEYSIDE,ENGLAND. UNIV PARIS 06,LPNHE,IN2P3 CNRS,F-75252 PARIS 05,FRANCE. UNIV PARIS 07,LPNHE,IN2P3 CNRS,F-75252 PARIS 05,FRANCE. LUND UNIV,DEPT PHYS,S-22363 LUND,SWEDEN. UNIV LYON 1,IPNL,IN2P3 CNRS,F-69622 VILLEURBANNE,FRANCE. UNIV COMPLUTENSE MADRID,E-28040 MADRID,SPAIN. UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. NIELS BOHR INST,DK-2100 COPENHAGEN 0,DENMARK. CHARLES UNIV,MFF,NUCL CTR,PRAGUE 18000,CZECH REPUBLIC. NIKHEF H,NL-1009 DB AMSTERDAM,NETHERLANDS. NATL TECH UNIV ATHENS,DEPT PHYS,GR-15773 ZOGRAFOS,GREECE. UNIV OSLO,DEPT PHYS,N-1000 OSLO 3,NORWAY. UNIV OVIEDO,DEPT FIS,OVIEDO 33006,SPAIN. UNIV OXFORD,DEPT PHYS,OXFORD OX1 3RH,ENGLAND. UNIV PADUA,DIPARTIMENTO FIS,I-35131 PADUA,ITALY. IST NAZL FIS NUCL,I-35131 PADUA,ITALY. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. UNIV ROMA TOR VERGATA,DIPARTIMENTO FIS,I-00173 ROME,ITALY. IST NAZL FIS NUCL,I-00173 ROME,ITALY. CENS,DAPNIA,DSM,F-91191 GIF SUR YVETTE,FRANCE. IST SUPER SANITA,IST NAZL FIS NUCL,I-00161 ROME,ITALY. UNIV CANTABRIA,CSIC,INST FIS CANTABRIA,SANTANDER 39006,SPAIN. INST HIGH ENERGY PHYS,PROTVINO,RUSSIA. UNIV LJUBLJANA,JOZEF STEFAN INST,SI-61000 LJUBLJANA,SLOVENIA. UNIV LJUBLJANA,DEPT PHYS,SI-61000 LJUBLJANA,SLOVENIA. UNIV STOCKHOLM,S-11385 STOCKHOLM,SWEDEN. UNIV TURIN,DIPARTIMENTO FIS SPERIMENTALE,I-10125 TURIN,ITALY. IST NAZL FIS NUCL,I-10125 TURIN,ITALY. UNIV TRIESTE,DIPARTMENTO FIS,I-34127 TRIESTE,ITALY. IST NAZL FIS NUCL,DIPARTMENTO FIS,I-34127 TRIESTE,ITALY. UNIV UDINE,IST FIS,I-33100 UDINE,ITALY. UNIV FED RIO DE JANEIRO,BR-21945970 RIO JANEIRO,BRAZIL. UNIV UPPSALA,DEPT RADIAT SCI,S-75121 UPPSALA,SWEDEN. UNIV VALENCIA,IFIC,CSIC,E-46100 BURJASSOT,SPAIN. UNIV VALENCIA,DFAMN,E-46100 BURJASSOT,SPAIN. AUSTRIAN ACAD SCI,INST HOCHENERGIEPHYS,A-1050 VIENNA,AUSTRIA. INST NUCL STUDIES,PL-00681 WARSAW,POLAND. UNIV WARSAW,PL-00681 WARSAW,POLAND. UNIV GESAMTHSCH WUPPERTAL,FACHBEREICH PHYS,D-42097 WUPPERTAL,GERMANY. RP Abreu, P (reprint author), UNIV AIX MARSEILLE 2,CPP,IN2P3 CNRS,F-13288 MARSEILLE 09,FRANCE. RI Contreras Gonzalez, Jose Luis/K-7255-2014; Navas, Sergio/N-4649-2014; Barrio, Juan/L-3227-2014; Zaitsev, Alexandre/B-8989-2017; Espirito Santo, Maria Catarina/L-2341-2014; Pimenta, Mario/M-1741-2013; gandelman, miriam/N-3739-2014; Ragazzi, Stefano/D-2463-2009; Cabrera Urban, Susana/H-1376-2015; Matorras, Francisco/I-4983-2015; Ferrer, Antonio/H-2942-2015; Rovelli, Tiziano/K-4432-2015; Smirnova, Oxana/A-4401-2013; Della Ricca, Giuseppe/B-6826-2013; Olshevskiy, Alexander/I-1580-2016; Paganoni, Marco/A-4235-2016; Dracos, Marcos/K-2335-2012; Hallgren, Allan/A-8963-2013; Botner, Olga/A-9110-2013; Michelotto, Michele/A-9571-2013; Mundim, Luiz/A-1291-2012; Yip, Kin/D-6860-2013; Marti-Garcia, Salvador/F-3085-2011; Monge, Maria Roberta/G-9127-2012; Nemecek, Stanislav/G-5931-2014; Ridky, Jan/H-6184-2014; Chudoba, Jiri/G-7737-2014; Fernandez, Ester/K-9734-2014; Nomerotski, Andrei/A-5169-2010; Katsanevas, Stavros/A-4297-2011; Ruiz, Alberto/E-4473-2011; branchini, paolo/A-4857-2011; Krammer, Manfred/A-6508-2010; De Saint Jean, Cyrille/E-8853-2011; Shellard, Ronald/G-4825-2012; Petrolini, Alessandro/H-3782-2011; Fruhwirth, Rudolf/H-2529-2012; de Paula, Leandro/I-9278-2012; Andreazza, Attilio/E-5642-2011; Verlato, Marco/J-4604-2012 OI Contreras Gonzalez, Jose Luis/0000-0001-7282-2394; Navas, Sergio/0000-0003-1688-5758; Barrio, Juan/0000-0002-0965-0259; Zaitsev, Alexandre/0000-0002-4961-8368; Espirito Santo, Maria Catarina/0000-0003-1286-7288; Pimenta, Mario/0000-0002-2590-0908; Ragazzi, Stefano/0000-0001-8219-2074; Matorras, Francisco/0000-0003-4295-5668; Ferrer, Antonio/0000-0003-0532-711X; Rovelli, Tiziano/0000-0002-9746-4842; Smirnova, Oxana/0000-0003-2517-531X; Della Ricca, Giuseppe/0000-0003-2831-6982; Olshevskiy, Alexander/0000-0002-8902-1793; Paganoni, Marco/0000-0003-2461-275X; Dracos, Marcos/0000-0003-0514-193X; Michelotto, Michele/0000-0001-6644-987X; Mundim, Luiz/0000-0001-9964-7805; Yip, Kin/0000-0002-8576-4311; Monge, Maria Roberta/0000-0003-1633-3195; Ridky, Jan/0000-0001-6697-1393; Ruiz, Alberto/0000-0002-3639-0368; Krammer, Manfred/0000-0003-2257-7751; Shellard, Ronald/0000-0002-2983-1815; Petrolini, Alessandro/0000-0003-0222-7594; de Paula, Leandro/0000-0002-4984-7734; Andreazza, Attilio/0000-0001-5161-5759; Verlato, Marco/0000-0003-1967-7655 NR 33 TC 48 Z9 48 U1 0 U2 5 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD AUG PY 1996 VL 71 IS 4 BP 539 EP 553 DI 10.1007/s002880050202 PG 15 WC Physics, Particles & Fields SC Physics GA VE207 UT WOS:A1996VE20700001 ER PT J AU Baur, R Breskin, A Chechik, R Drees, A Jacob, C Faschingbauer, U Fischer, P Fraenkel, Z Gatti, E Glassel, P Gunzel, T delosHeros, CP Hess, F Irmscher, D Lenkeit, B Olsen, LH Panebrattsev, Y Pfeiffer, A Ravinovich, I Rehak, P Schon, A Schukraft, J Sampietro, M Shor, A Specht, HJ Steiner, V Tapprogge, S TelZur, G Tserruya, I Ullrich, T Wurm, JP AF Baur, R Breskin, A Chechik, R Drees, A Jacob, C Faschingbauer, U Fischer, P Fraenkel, Z Gatti, E Glassel, P Gunzel, T delosHeros, CP Hess, F Irmscher, D Lenkeit, B Olsen, LH Panebrattsev, Y Pfeiffer, A Ravinovich, I Rehak, P Schon, A Schukraft, J Sampietro, M Shor, A Specht, HJ Steiner, V Tapprogge, S TelZur, G Tserruya, I Ullrich, T Wurm, JP TI Search for direct photons from S-Au collisions at 200 GeV/nucleon SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; HEAVY-ION COLLISIONS; QUARK-GLUON PLASMA; ETA-PRODUCTION; HADRON-PRODUCTION; DETECTORS; GEV/U; PAIRS; PI-0 AB The CERES experiment has measured inclusive photon production in S-Au collisions of 200 GeV/nucleon at the CERN SPS. No evidence for direct emission of photons was found. For the kinematic region 2.1 < y < 2.65 and 0.4 GeV/c < p(perpendicular to) < 2.0 GeV/c the yield and p(perpendicular to)-dependence of the observed photons are well reproduced by hadron decays. Furthermore, their production rate is found to be proportional to the charged particle density. The systematic errors comparing the measured and expected photon yield result in an upper limit of 14% for the emission of direct photons in central S-Au collisions. For a photon source with a yield depending quadratically on the charged particle density the limit can be reduced to 7%. C1 WEIZMANN INST SCI,IL-76100 REHOVOT,ISRAEL. MAX PLANCK INST KERNPHYS,D-69117 HEIDELBERG,GERMANY. POLITECN MILAN,I-20133 MILAN,ITALY. BROOKHAVEN NATL LAB,UPTON,NY 11973. CERN,CH-1211 GENEVA 23,SWITZERLAND. RP Baur, R (reprint author), UNIV HEIDELBERG,INST PHYS,D-69120 HEIDELBERG,GERMANY. RI BRESKIN, AMOS/K-1549-2012; Sampietro, Marco/A-3732-2016 OI Sampietro, Marco/0000-0003-4825-9612 NR 43 TC 26 Z9 26 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD AUG PY 1996 VL 71 IS 4 BP 571 EP 577 DI 10.1007/s002880050204 PG 7 WC Physics, Particles & Fields SC Physics GA VE207 UT WOS:A1996VE20700003 ER PT J AU Connick, RE Zhang, YX AF Connick, RE Zhang, YX TI Kinetics and mechanism of the oxidation of HSO3- by O-2 .2. The manganese(II)-catalyzed reaction SO INORGANIC CHEMISTRY LA English DT Article ID SULFUR-DIOXIDE OXIDATION; AQUEOUS S(IV) OXIDATION; METAL-IONS; CATALYZED AUTOXIDATION; SULFITE; PH AB The Mn2+-catalyzed oxidation of HSO3- by O-2 has been studied in the pH region 4.5 and at bisulfite ion concentrations from 1.5 x 10(-3) to 1.2 x 10(-2) M. The reaction was found to obey a three-term rate law: -d[O-2]/dt = k(alpha)[HSO3-](2) + k(beta)[HSO3-][Mn2+] + k(gamma)[Mn2+](2) with k(alpha) = 3.6 x 10(-3) M(-1) s(-1), k(beta) = 1.23 M(-1) s(-1), and k(gamma) = 98.6 M(-1) s(-1) at pH 4.50, 25 degrees C, and ionic strength 0.050 M. The kinetic behavior of the reaction resembles markedly that of the uncatalyzed reaction. The rate of the reaction is independent of oxygen concentration, S2O72- and HSO5- are intermediates in the reaction, and the reaction is catalyzed by S2O82- and strongly inhibited by methanol, The experimental results can be quantitatively explained by the addition to the uncatalyzed reaction mechanism of a chain propagation reaction involving Mn2+ and SO5.-. Among several alternatives, the manganese propagation may be represented as follows: (I) Mn2+ + SO5.- --> Mn(III) + HSO5-; (II) Mn(III) + HSO3- --> Mn2+ + SO3.-. The resulting mechanism leads to the three-term rate law where the first term is the uncatalyzed rate and the second term can be predicted quantitatively from the uncatalyzed rate and the last term. It was inferred from the yield of S2O72- that, unlike the reaction between SO5.- and HSO3-, there is little or no branching of the first reaction to form the SO4.- radical. The ratio of the rate constant of (I) to that of the reaction of SO5.- with HSO3- in the uncatalyzed reaction mechanism has been determined to be 124. The quantitative agreement between the experimental data and predictions for the effect of S2O82- has substantiated the validity of the proposed mechanism. The pH dependence of the reaction rate can be almost entirely accounted for by the pH dependence of the reaction between HSO5- and HSO3-, indicating that reaction I is independent of the hydrogen ion concentration in the pH region studied. While methanol inhibits the reaction, the quantitative discrepancy between predictions and experiments suggests that the reactions with alcohols are more complex than previously thought, Further work in this area is needed to understand fully the reaction mechanism when alcohol is present. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Connick, RE (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM,BERKELEY,CA 94720, USA. NR 32 TC 48 Z9 48 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JUL 31 PY 1996 VL 35 IS 16 BP 4613 EP 4621 DI 10.1021/ic951141i PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VB408 UT WOS:A1996VB40800015 ER PT J AU Guloy, AM Corbett, JD AF Guloy, AM Corbett, JD TI La(15)Ge(9)Z. Interstitial derivatives with an ordered superstructure of the Mn5Si3 structure type. Property trends in a series of homologous intermetallic phases SO INORGANIC CHEMISTRY LA English DT Article ID TRANSITION-METALS; CLUSTER PHASES; CHEMISTRY; SYSTEM; EARTH; HOST; HALIDES; ZR5SB3; MN; NI AB The phases La(15)Ge(9)Z, Z = Mn, Fe, Co, Ni, Cu, Ru, C, O, P, have been obtained from reactions of either the elements or suitable binary compounds in sealed Ta containers at 1200-1350 degrees C. All exhibit an ordered root 3a x root 3a x c superstructure of the Mn5Si3 type (La(5)Ge(3)Z, La(5)Ge(3)Z, P6(3)/mcm) in which two-thirds of the slightly distorted confacial chains of trigonal antiprisms (La6/2Ge6/2) have Z bound in alternate, contracted interstitial sites. The room-temperature structures for Z = Mn, Fe, Co, Ni, C, P were refined from single-crystal data (space group P6(3)mc, Z = 2; for the protypical Fe, a = 15.4810(2) Angstrom and c = 6.8768(3) Angstrom). The unit cell lengths and volumes and d(Z-Z) values show notably smaller variations with Z than in La(5)Ge(3)Z or related systems. The buffering effect of empty cavities in the commensurate chains and the weak La-La bonding appear to be responsible. Magnetic susceptibility data and XPS core shifts are reported for the Fe and, in part, the Co and Ni phases La(15)Ge(9)Z. All three are metallic with decreasing moments of similar to 1.83, similar to 0.3, and similar to 0 mu(3), respectively. In contrast, the Fe-richer La5Ge3Fe is a very soft ferromagnet at room temperature. Members of the sequence Fe, La5Ge3Fe, La15Ge9Fe exhibit regularly decreasing moments as well. The Fe 2p(3/2) core levels show a 1.7 eV decrease over the same series, i.e., increasing reduction, while an evidently regular oxidation of La from the element through La5Ge3 and La15Ge9Fe to La(5)e(3)Fe is indicated by a regular overall increase of 2.7 eV in La 3d(5/2) binding energies. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. NR 34 TC 43 Z9 43 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JUL 31 PY 1996 VL 35 IS 16 BP 4669 EP 4675 DI 10.1021/ic9515158 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VB408 UT WOS:A1996VB40800023 ER PT J AU Baltisberger, JH Xu, Z Stebbins, JF Wang, SH Pines, A AF Baltisberger, JH Xu, Z Stebbins, JF Wang, SH Pines, A TI Triple-quantum two-dimensional Al-27 magic-angle spinning nuclear magnetic resonance spectroscopic study of aluminosilicate and aluminate crystals and glasses SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MAS-NMR-SPECTROSCOPY; EARTH BOROALUMINATE CRYSTALS; SI-AL ORDER; QUADRUPOLAR NUCLEI; SATELLITE TRANSITIONS; LOCAL-STRUCTURE; LEUCITE; SI-29; SPECTRA; ANORTHITE AB A new two-dimensional magic-angle spinning NMR experiment(1,2) using multiple-quantum coherences of half-integer quadrupolar nuclei was used to study Al-27 sites in crystalline samples of leucite (KAlSi2O6), anorthite (CaAl2Si2O8), and kyanite (Al2SiO5), as well as CaAl2Si2O8 glass and a magnesium aluminoborate glass. In the crystals, multiple sites are partially resolved and new results for isotropic chemical shifts and quadrupolar parameters are derived, using data collected at a single magnetic field. Data for both leucite and anorthite are consistent with previous results that correlate chemical shifts with mean intertetrahedral bond angle. Signal can be obtained from sites with quadrupolar coupling constants as large as 9 MHz, but intensities are reduced. In the aluminoborate glass, peaks for sites with different Al coordination numbers are well separated. The lack of such features in CaAl2Si2O8 glass rules out the presence of significant quantities of AlO5 and AlO6 groups. C1 STANFORD UNIV,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305. BEREA COLL,DEPT CHEM,BEREA,KY 40404. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NR 31 TC 154 Z9 155 U1 2 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 31 PY 1996 VL 118 IS 30 BP 7209 EP 7214 DI 10.1021/ja9606586 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA VA026 UT WOS:A1996VA02600027 ER PT J AU Braun, J Limbach, HH Williams, PG Morimoto, H Wemmer, DE AF Braun, J Limbach, HH Williams, PG Morimoto, H Wemmer, DE TI Observation of kinetic tritium isotope effects by dynamic NMR. The tautomerism of porphyrin SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DOUBLE PROTON-TRANSFER; FREE-BASE PORPHYRINS; HH/HD/DD ISOTOPE; SOLID-STATE; MIGRATION; EXCHANGE; SOLVENT; MATRIX C1 LAWRENCE BERKELEY LAB,NATL TRITIUM LABELLING FACIL,BERKELEY,CA 94720. RP Braun, J (reprint author), FREE UNIV BERLIN,INST ORGAN CHEM,TAKUSTR 3,D-14195 BERLIN,GERMANY. RI Limbach, Hans-Heinrich/G-8858-2011 OI Limbach, Hans-Heinrich/0000-0002-2084-6359 NR 25 TC 71 Z9 71 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 31 PY 1996 VL 118 IS 30 BP 7231 EP 7232 DI 10.1021/ja954146n PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VA026 UT WOS:A1996VA02600036 ER PT J AU Vavasis, SA Ye, YY AF Vavasis, SA Ye, YY TI A primal-dual interior point method whose running time depends only on the constraint matrix SO MATHEMATICAL PROGRAMMING LA English DT Article DE interior point method; linear programming; complexity; strongly polynomial time; layered least squares; central path ID NONLINEAR GEOMETRY; SCALED PROJECTIONS; LINEAR-PROGRAMS; ALGORITHMS; PATH; PSEUDOINVERSES; TRAJECTORIES AB We propose a primal-dual ''layered-step'' interior point (LIP) algorithm for linear programming with data given by real numbers. This algorithm follows the central path, either with short steps or with a new type of step called a ''layered least squares'' (LLS) step. The algorithm returns an exact optimum after a finite number of steps-in particular, after O(n(3.5) c(A)) iterations, where c(A) is a function of the coefficient matrix. The LLS steps can be thought of as accelerating a classical path-following interior point method. One consequence of the new method is a new characterization of the central path: we show that it composed of at most n(2) alternating straight and curved segments, If the LIP algorithm is applied to integer data, we get as another corollary a new proof of a well-known theorem by Tardos that linear programming can be solved in strongly polynomial time provided that A contains small-integer entries. C1 UNIV IOWA,DEPT MANAGEMENT SCI,IOWA CITY,IA 52242. SANDIA NATL LABS,LIVERMORE,CA 94550. CORNELL UNIV,CORNELL THEORY CTR,ITHACA,NY 14853. RP Vavasis, SA (reprint author), CORNELL UNIV,DEPT COMP SCI,UPSON HALL,ITHACA,NY 14853, USA. NR 44 TC 64 Z9 67 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0025-5610 J9 MATH PROGRAM JI Math. Program. PD JUL 31 PY 1996 VL 74 IS 1 BP 79 EP 120 DI 10.1007/BF02592148 PG 42 WC Computer Science, Software Engineering; Operations Research & Management Science; Mathematics, Applied SC Computer Science; Operations Research & Management Science; Mathematics GA VD967 UT WOS:A1996VD96700007 ER PT J AU Cosman, M Hingerty, BE Luneva, N Amin, S Geacintov, NE Broyde, S Patel, DJ AF Cosman, M Hingerty, BE Luneva, N Amin, S Geacintov, NE Broyde, S Patel, DJ TI Solution conformation of the (-)-cis-anti-Benzo[a]pyrenyl-dG adduct opposite dC in a DNA duplex: Intercalation of the covalently attached BP ring into the helix with base displacement of the modified deoxyguanosine into the major groove SO BIOCHEMISTRY LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; DEOXYADENOSINE N-6-AMINO GROUP; DIASTEREOMERIC BENZOPYRENE 7,8-DIOL-9,10-EPOXIDES; NMR SOLUTION STRUCTURE; DG MISMATCH OPPOSITE; DIOL-EPOXIDE; OPTICAL ENANTIOMERS; TRANS ADDITION; NONANUCLEOTIDE DUPLEX; MAMMALIAN-CELLS AB This paper reports on the combined NMR-molecular mechanics computational studies of the solution structure of the (-)-cis-anti-[BP]dG adduct positioned opposite dC in the sequence context d(C1-C2-A3-T4-C5-[BP]G6-C7-T8-A9-C10-C11). d(G12-G13-T14-A15-G16-C17-G18-A19-T20-G21-G22) duplex [designated (-)-cis-anti-[BP]dG . dC 11-mer duplex]. This adduct is derived from cis addition at C-10 of (-)-anti-7(S),8(R)-dihydroxy-9(R),10(S)-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene [(-)-anti-BPDE] to the N-2 position of dG6 in this duplex sequence. The exchangeable and nonexchangeable protons of tile benzo[a]pyrenyl moiety and nucleic acid of the major conformation were assigned following analysis of two-dimensional NMR data sets in H2O and D2O solution, There was a general broadening of proton resonances for a three-nucleotide segment centered about the lesion site which resulted in a tentative assignment for the sugar protons of the C7 residue in the spectrum of the adduct duplex. The solution conformation of the major conformation of the (-)-cis-anti-[BP]dG . dC 11-mer duplex has been determined by incorporating DNA-DNA and intermolecular BP-DNA proton-proton distances defined by lower and upper bounds deduced from NOESY data sets as restraints in molecular mechanics computations in torsion angle space. The results establish that the covalently attached benzo[tr]pyrenyl ring intercalates between intact Watson-Crick dC5 . dG18 and dC7 . dG16 base pairs. The modified deoxyguanosine [BP]dG6 and its partner cytosine dC17 are looped out of the helix into the major groove, The purine ring of the [BP]dG6 residue is directed toward the 5'-end of the modified strand and stacks over the major groove edge of its 5'-side neighbor dC5 residue, The solution structure of the (-)-cis-anti-[BP]dG . dC 11-mer duplex is compared with those of die stereoisomeric (+)-trans-anti-[BP]dG [Cosman, M., et al. (1992) Proc. Natl, Acad. Sci. U.S.A. 89, 1914-1918], (-)-trans-anti[BP]dG [de los Santos, C., et al. (1992) Biochemistry 31, 5245-5252], and (+)-cis-anti-[BP]dG [Cosman, M., et al. (1993a) Biochemistry 32, 4146-4155] adducts positioned opposite dC in the same duplex sequence context. A key finding is that the long axes of the intercalated benzo[a]pyrenyl rings in the solution structures of the (+)- and (-)-cis-anti-[BP]dG . dC Il-mer duplexes are oriented in opposite directions with the benzylic ring directed toward the minor groove in the (+)-cis isomer and toward the major groove in the (-)-cis isomer. In addition, a comparison is also made with the solution structure of the (+)-trans-anti-[BP]dG adduct opposite a deletion site [Cosman, M., et al. ( 1994a) Biochemistry 33, 11507-11517] since this adduct duplex displays several conformational features in common with the structure of the (-)-cis-anti- [BP]dG . dC 11-mer duplex. The structures of both duplex adducts exhibit intercalation of the covalently attached ligand into the helix and displacement of the modified deoxyguanosine into the major groove. Studies of the biological activities of stereochemically defined BP-DNA adducts and the comparison of the solution structure of the (-)-cis-anti-[BP]dG . dC 11-mer duplex with its stereoisomeric counterparts should lead to new insights into the relationships between defined helical distortions and mutagenic specificity and activity. C1 MEM SLOAN KETTERING CANC CTR,CELLULAR BIOCHEM & BIOPHYS PROGRAM,NEW YORK,NY 10021. OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN 37831. AMER HLTH FDN,VALHALLA,NY 10595. NYU,DEPT BIOL,NEW YORK,NY 10003. NYU,DEPT CHEM,NEW YORK,NY 10003. FU NCI NIH HHS [CA-46533, CA-20851, CA-28038] NR 60 TC 74 Z9 75 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 30 PY 1996 VL 35 IS 30 BP 9850 EP 9863 DI 10.1021/bi9605346 PG 14 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VA025 UT WOS:A1996VA02500026 PM 8703959 ER PT J AU Holland, OW Fathy, D Sadana, DK AF Holland, OW Fathy, D Sadana, DK TI Formation of ultrathin, buried oxides in Si by O+ ion implantation SO APPLIED PHYSICS LETTERS LA English DT Article ID TECHNOLOGY; SILICON; CMOS AB A technique is presented for forming a silicon-on-insulator material with an ultrathin buried oxide by utilizing the separation by implantation of oxygen or SIMOX method. It overcomes the problem of oxide continuity encountered during standard SIMOX processing when the O+-implanted dose is scaled down to decrease the thickness of the buried oxide below similar to 0.1 mu m. To promote the formation of ultrathin buried oxides (during post-implantation annealing), the implantation process was modified to produce a microstructure which promotes coalescence of the oxygen into a continuous layer. This was accomplished by slightly modifying the standard (>500 degrees C) process so that the final increment of the dose is implanted near room temperature. This dose is chosen to selectively amorphize the region near the ion's range which will yield a high-defective layer during subsequent annealing. It is shown that this layer, which can consist of polysilicon, provides a template or guide upon which the oxide farms. Buried oxides prepared in this way are shown to be continuous and without Si inclusions while the standard process yields a broken layer with severe discontinuities. (C) 1995 American Institute of Physics. C1 N CAROLINA STATE UNIV,RALEIGH,NC 27695. IBM CORP,TJ WATSON RES CTR,YORKTOWN HTS,NY 10598. RP Holland, OW (reprint author), OAK RIDGE NATL LAB,BLDG 3003 MS-6048,OAK RIDGE,TN 37831, USA. NR 16 TC 34 Z9 35 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 29 PY 1996 VL 69 IS 5 BP 674 EP 676 DI 10.1063/1.117802 PG 3 WC Physics, Applied SC Physics GA UZ024 UT WOS:A1996UZ02400028 ER PT J AU Wignall, GD Alamo, RG Londono, JD Mandelkern, L Stehling, FC AF Wignall, GD Alamo, RG Londono, JD Mandelkern, L Stehling, FC TI Small-angle neutron scattering investigations of liquid-liquid phase separation in heterogeneous linear low-density polyethylene SO MACROMOLECULES LA English DT Article ID SATURATED-HYDROCARBON POLYMERS; BRANCHED POLYETHYLENES; BLENDS; FRACTIONATION; BEHAVIOR; THERMODYNAMICS; PARAMETER; MOLTEN; CHAINS; STATE AB The issue of multiple equilibrium phases in compositionally heterogeneous random copolymers has been addressed by a series of small-angle neutron scattering (SANS) experiments. An ethylene-hexene (EH) copolymer, representative of many linear low-density polyethylenes (LLDPE) has been shown to contain a dispersed minority phase (volume fraction, phi similar to 0.02) consisting of highly branched, amorphous material. The dispersed phase is eliminated to a good approximation by xylene extraction, which removes the low molecular weight and highly branched molecules. The extracted material contains a much higher fraction of branched molecules and hence has a greater proportion of the dispersed phase (phi similar to 0.2). These findings support the prediction of liquid-liquid phase separation for compositionally polydisperse LLDPEs, whereby the more highly branched molecules in the distribution may phase segregate, even if the overall branch content is low. C1 FLORIDA A&M UNIV,TALLAHASSEE,FL 32310. FLORIDA STATE UNIV,COLL ENGN,DEPT CHEM ENGN,TALLAHASSEE,FL 32310. FLORIDA STATE UNIV,INST MOL BIOPHYS,TALLAHASSEE,FL 32306. EXXON CHEM CO,PLAST & TECHNOL DIV,BAYTOWN,TX 77520. RP Wignall, GD (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. OI Wignall, George/0000-0002-3876-3244 NR 27 TC 41 Z9 41 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUL 29 PY 1996 VL 29 IS 16 BP 5332 EP 5335 DI 10.1021/ma960050h PG 4 WC Polymer Science SC Polymer Science GA VA221 UT WOS:A1996VA22100013 ER PT J AU Hongladarom, K Ugaz, VM Cinader, DK Burghardt, WR Quintana, JP Hsiao, BS Dadmun, MD Hamilton, WA Butler, PD AF Hongladarom, K Ugaz, VM Cinader, DK Burghardt, WR Quintana, JP Hsiao, BS Dadmun, MD Hamilton, WA Butler, PD TI Birefringence, X-ray scattering, and neutron scattering measurements of molecular orientation in sheared liquid crystal polymer solutions SO MACROMOLECULES LA English DT Article ID POLY(BENZYL GLUTAMATE) SOLUTIONS; ARAMID SOLUTIONS; IN-SITU; RHEOLOGY; FLOW; HYDROXYPROPYLCELLULOSE; BEHAVIOR; TEXTURE; ALIGNMENT; PBZT AB Recent studies of molecular orientation in sheared liquid crystalline polymers have often yielded contradictory results. To check the self-consistency of methods for quantitative measurements of molecular orientation, liquid crystalline solutions of (hydroxypropyl)cellulose [HPC] and poly(benzyl glutamate) [PEG] have been studied using flow birefringence, X-ray scattering, and neutron scattering. HPC X-ray scattering patterns show an arclike pattern with a distinct peak as a function of scattering vector, while PEG patterns show a more diffuse equitorial streak. These differences are attributed to more strongly correlated lateral packing in HPC solutions due to their higher concentration. Measurements of orientation in steady shear flow agree well among the three techniques. Lyotropic HPC and PEG solutions differ in orientation at low shear rates. KPC solutions exhibit near zero orientation at low rates, while X-ray and neutron scattering measurements confirm previous birefringence data showing a low shear rate plateau of moderate orientation in PEG. Differences with recent neutron scattering measurements on PEG solutions that show low orientation at low shear rate are attributed to choice of solvent, rather than choice of technique. X-ray and optical data are consistent in showing decreasing orientation in HPC solutions during relaxation, but discrepancies are found in relaxation of PEG solutions. Large increases in flow birefringence suggest substantial orientation enhancement. X-ray data on one PEG solution confirm increasing orientation, but X-ray and neutron scattering data on a more concentrated solution show only modest changes in orientation. It is suggested that flow birefringence fails in this case due to texture coarsening to the point where there is no longer effective averaging over the distribution of director orientations along the light path. C1 NORTHWESTERN UNIV,DEPT CHEM ENGN,EVANSTON,IL 60208. NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. DUPONT CO INC,CENT RES & DEV,WILMINGTON,DE 19880. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RI Burghardt, Wesley/B-7642-2009; Butler, Paul/D-7368-2011 NR 35 TC 81 Z9 81 U1 6 U2 42 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUL 29 PY 1996 VL 29 IS 16 BP 5346 EP 5355 DI 10.1021/ma960171h PG 10 WC Polymer Science SC Polymer Science GA VA221 UT WOS:A1996VA22100015 ER PT J AU Ahuja, S Dieckman, SL Gopalsami, N Raptis, AC AF Ahuja, S Dieckman, SL Gopalsami, N Raptis, AC TI H-1 NMR imaging and spectroscopy studies of the polymerization of acrylamide gels SO MACROMOLECULES LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; H-1-NMR; POLY(ACRYLAMIDE); MOTION; TIME AB H-1 nuclear magnetic resonance spectra and images have been acquired during polymerization of a mixture of soluble reactive methacrylamide (monomer) and N,N'-methylenebisacrylamide (cross-linking molecule). The mixture was polymerized by adding ammonium persulfate (initiator) and tetramethylethylenediamine (accelerator) to form long-chain, cross-linked polymers. Study of the time-varying spin-lattice relaxation times (T-1) during the polymerization was conducted at 25 and 35 degrees C and the variation of spectra and T-1 with respect to the extent of polymerization was determined. To verify homogeneous polymerization, multidimensional H-1 NMR imaging was utilized for in-situ monitoring of the process. The intensities from the images are modeled and the correspondence shows a direct extraction of T-1 data from the images. RP Ahuja, S (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,SENSORS INSTRUMENTAT & NONDESTRUCT EVALUAT SECT,ARGONNE,IL 60439, USA. NR 20 TC 12 Z9 12 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUL 29 PY 1996 VL 29 IS 16 BP 5356 EP 5360 DI 10.1021/ma960216e PG 5 WC Polymer Science SC Polymer Science GA VA221 UT WOS:A1996VA22100016 ER PT J AU Speir, RA AF Speir, RA TI Time will tell SO OIL & GAS JOURNAL LA English DT Letter RP Speir, RA (reprint author), US DOE,POLICY OFF,WASHINGTON,DC, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO ENERGY GROUP PI TULSA PA 1421 S SHERIDAN RD PO BOX 1260, TULSA, OK 74101 SN 0030-1388 J9 OIL GAS J JI Oil Gas J. PD JUL 29 PY 1996 VL 94 IS 31 BP 8 EP & PG 2 WC Energy & Fuels; Engineering, Petroleum SC Energy & Fuels; Engineering GA UZ818 UT WOS:A1996UZ81800002 ER PT J AU Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Wang, R Coan, TE Dominick, J Fadeyev, V Korolkov, I Lambrecht, M Sanghera, S Shelkov, V Stroynowski, R Volobouev, I Wei, G Artuso, M Efimov, A Gao, M Goldberg, M He, D Horwitz, N Kopp, S Moneti, GC Mountain, R Mukhin, Y Playfer, S Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Kinoshita, K Pomianowski, P Schrenk, S Cinabro, D Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Athanas, M Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Korte, CM Kutschke, R Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Cho, K Ford, WT Lohner, M Park, H Rankin, P Roy, K Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Dumas, DJ Ehrlich, R Elia, R Gaidarev, P Gittelman, B Gray, SW Hartill, DL Heltsley, BK Jones, CD Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Avery, P Prescott, C Yang, S Yelton, J Brandenburg, G Briere, RA Liu, T Saulnier, M Wilson, R Yamamoto, H Browder, TE Li, F Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Palmer, M Selen, M Thaler, JJ Edwards, KW McLean, KW Ogg, M Bellerive, A Britton, DI Janicek, R MacFarlane, DB Patel, PM Spaan, B Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Copty, N Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Kubota, Y Lattery, M Nelson, JK Patton, S Poling, R Riehle, T Savinov, V Alam, MS Kim, LJ Ling, Z Mahmood, AH ONeill, JJ Severini, H Sun, CR Timm, S Wappler, F Duboscq, JE Fulton, R Fujino, D Gan, KK Honscheid, K Kagan, H Kass, R Lee, J Sung, M Undrus, A White, C Wanke, R Wolf, A Zoeller, MM Fu, X Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miao, T Miller, DH Modesitt, M Shibata, EI Shipsey, IPJ Wang, PN AF Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Wang, R Coan, TE Dominick, J Fadeyev, V Korolkov, I Lambrecht, M Sanghera, S Shelkov, V Stroynowski, R Volobouev, I Wei, G Artuso, M Efimov, A Gao, M Goldberg, M He, D Horwitz, N Kopp, S Moneti, GC Mountain, R Mukhin, Y Playfer, S Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Kinoshita, K Pomianowski, P Schrenk, S Cinabro, D Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Athanas, M Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Korte, CM Kutschke, R Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Cho, K Ford, WT Lohner, M Park, H Rankin, P Roy, K Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Dumas, DJ Ehrlich, R Elia, R Gaidarev, P Gittelman, B Gray, SW Hartill, DL Heltsley, BK Jones, CD Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Avery, P Prescott, C Yang, S Yelton, J Brandenburg, G Briere, RA Liu, T Saulnier, M Wilson, R Yamamoto, H Browder, TE Li, F Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Palmer, M Selen, M Thaler, JJ Edwards, KW McLean, KW Ogg, M Bellerive, A Britton, DI Janicek, R MacFarlane, DB Patel, PM Spaan, B Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Copty, N Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Kubota, Y Lattery, M Nelson, JK Patton, S Poling, R Riehle, T Savinov, V Alam, MS Kim, LJ Ling, Z Mahmood, AH ONeill, JJ Severini, H Sun, CR Timm, S Wappler, F Duboscq, JE Fulton, R Fujino, D Gan, KK Honscheid, K Kagan, H Kass, R Lee, J Sung, M Undrus, A White, C Wanke, R Wolf, A Zoeller, MM Fu, X Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miao, T Miller, DH Modesitt, M Shibata, EI Shipsey, IPJ Wang, PN TI Observation of an excited charmed baryon decaying into Xi(c)(0)pi(+) SO PHYSICAL REVIEW LETTERS LA English DT Article ID STRANGENESS AB Using data recorded by the CLEO II detector at the Cornell Electron Storage Ring, we report the first observation of an excited charmed baryon decaying into Xi c(0) pi(+). The state has mass difference M(Xi(c)(0) pi(+)) - M(Xi(c)(0)) of 174.3 +/- 0.5 +/- 1.0 MeV/c(2), and a width of <3.1 MeV/c(2) (90% confidence level limit). We identify the new state as the Xi(c)(*+), the isospin partner of the recently discovered Xi(c)(0*). C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. SO METHODIST UNIV,DALLAS,TX 75275. SYRACUSE UNIV,SYRACUSE,NY 13244. VANDERBILT UNIV,NASHVILLE,TN 37235. VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. WAYNE STATE UNIV,DETROIT,MI 48202. CALTECH,PASADENA,CA 91125. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV COLORADO,BOULDER,CO 80309. CORNELL UNIV,ITHACA,NY 14853. UNIV FLORIDA,GAINESVILLE,FL 32611. HARVARD UNIV,CAMBRIDGE,MA 02138. UNIV HAWAII MANOA,HONOLULU,HI 96822. UNIV ILLINOIS,CHAMPAIGN URBANA,IL 61801. CARLETON UNIV,OTTAWA,ON K1S 5B6,CANADA. MCGILL UNIV,MONTREAL,PQ H3A 2T8,CANADA. ITHACA COLL,ITHACA,NY 14850. UNIV KANSAS,LAWRENCE,KS 66045. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. SUNY ALBANY,ALBANY,NY 12222. OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV OKLAHOMA,NORMAN,OK 73019. PURDUE UNIV,W LAFAYETTE,IN 47907. BINP,RU-630090 NOVOSIBIRSK,RUSSIA. RP Gibbons, L (reprint author), UNIV ROCHESTER,601 ELMWOOD AVE,ROCHESTER,NY 14627, USA. RI Schaffner, Stephen/D-1189-2011; Briere, Roy/N-7819-2014; OI Briere, Roy/0000-0001-5229-1039; Poling, Ronald/0000-0001-7305-4702; Bloom, Kenneth/0000-0002-4272-8900 NR 13 TC 50 Z9 51 U1 1 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 JUL 29 PY 1996 VL 77 IS 5 BP 810 EP 813 DI 10.1103/PhysRevLett.77.810 PG 4 WC Physics, Multidisciplinary SC Physics GA UY952 UT WOS:A1996UY95200005 ER PT J AU Phair, L Moretto, LG Wozniak, GJ deSouza, RT Bowman, DR Carlin, N Gelbke, CK Gong, WG Kim, YD Lisa, MA Lynch, WG Peaslee, GF Tsang, MB Zhu, F AF Phair, L Moretto, LG Wozniak, GJ deSouza, RT Bowman, DR Carlin, N Gelbke, CK Gong, WG Kim, YD Lisa, MA Lynch, WG Peaslee, GF Tsang, MB Zhu, F TI Reducibility and thermal and mass scaling in angular correlations from multifragmentation reactions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; AZIMUTHAL CORRELATION-FUNCTIONS; NONEQUILIBRIUM LIGHT PARTICLES; E/A = 35; REACTION PLANE; MEAN-FIELD; EMISSION; FRAGMENTS; DYNAMICS; AU-197 AB The azimuthal angular correlations of light charged particles and light intermediate mass fragments emitted from the reaction Ar-36 + Au-197 at E/A = 50 MeV are found to be reducible to the angular distributions of individual fragments. Thermal scaling is also observed in the coefficients of the angular correlations. Furthermore, the observed scaling with fragment mass seems to imply secondary emission from relatively small (A approximate to 15-30) primary fragments. C1 MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. MICHIGAN STATE UNIV,NATL SUPERCOND CYCLOTRON LAB,E LANSING,MI 48824. RP Phair, L (reprint author), LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. RI Carlin Filho, Nelson/C-2187-2012; Lynch, William/I-1447-2013; deSouza, Romualdo/P-5862-2015 OI Lynch, William/0000-0003-4503-176X; deSouza, Romualdo/0000-0001-5835-677X NR 25 TC 14 Z9 15 U1 1 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 JUL 29 PY 1996 VL 77 IS 5 BP 822 EP 825 DI 10.1103/PhysRevLett.77.822 PG 4 WC Physics, Multidisciplinary SC Physics GA UY952 UT WOS:A1996UY95200008 ER PT J AU LopezUrrutia, JRC Beiersdorfer, P Savin, DW Widmann, K AF LopezUrrutia, JRC Beiersdorfer, P Savin, DW Widmann, K TI Direct observation of the spontaneous emission of the hyperfine transition F=4 to F=3 in ground state hydrogenlike Ho-165(66+) in an electron beam ion trap SO PHYSICAL REVIEW LETTERS LA English DT Article AB We report the first direct laboratory measurement of the spontaneous emission due to the hyperfine splitting of the ground state of a highly charged hydrogenlike ion excited by electron collisions. The transition between the F = 4 and F = 3 levels of the 1s(2)S(1/2) configuration of hydrogenlike Ho-165(65+) was observed and its wavelength was determined to 5726.4 +/- 1.5 Angstrom. After taking into account relativistic, nuclear charge distribution, Bohr-Weisskopf, and QED corrections, we observe a significant deviation from commonly tabulated values of the nuclear dipole magnetic moment of this nucleus. RP LopezUrrutia, JRC (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Crespo Lopez-Urrutia, Jose R./F-7069-2011; Savin, Daniel/B-9576-2012 OI Crespo Lopez-Urrutia, Jose R./0000-0002-2937-8037; Savin, Daniel/0000-0002-1111-6610 NR 17 TC 119 Z9 120 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 29 PY 1996 VL 77 IS 5 BP 826 EP 829 PG 4 WC Physics, Multidisciplinary SC Physics GA UY952 UT WOS:A1996UY95200009 ER PT J AU Hamilton, JC AF Hamilton, JC TI Magic size effects for heteroepitaxial island diffusion SO PHYSICAL REVIEW LETTERS LA English DT Article ID CLUSTERS AB Activation energies for diffusion of small heteroepitaxial islands by nucleation and motion of a dislocation across the island are calculated using a Frenkel-Kontorova model. At ''magic island sizes'' the activation barriers for heteroepitaxial island diffusion are dramatically lowered. Total energy calculations and molecular dynamics simulations using the embedded atom method confirm the existence of a rapid diffusion process for two-dimensional islands. A signature of this process is a strongly temperature dependent activation energy for diffusion. RP Hamilton, JC (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94550, USA. NR 18 TC 57 Z9 57 U1 0 U2 5 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 JUL 29 PY 1996 VL 77 IS 5 BP 885 EP 888 DI 10.1103/PhysRevLett.77.885 PG 4 WC Physics, Multidisciplinary SC Physics GA UY952 UT WOS:A1996UY95200024 ER PT J AU Bulaevskii, LN Vinokur, VM Maley, MP AF Bulaevskii, LN Vinokur, VM Maley, MP TI Reversible magnetization of irradiated high-T-c superconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSON LOCALIZATION; VORTEX STATE; VORTICES; FLUCTUATIONS; BI2SR2CACU2O8 AB We calculate the free energy and equilibrium magnetization in highly anisotropic layered superconductors with strong defects produced by irradiation. We account for the entropy associated with different configurations of pancakes inside and outside of strong defects. We show how magnetization measurements provide information on pinning energy and how they determine the magnetic fields and temperatures at which pancake vortices are trapped inside strong defects. We discuss also the behavior of magnetization which may signal about decoupling of pancakes inside columnar defects. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Bulaevskii, LN (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 27 TC 34 Z9 34 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 JUL 29 PY 1996 VL 77 IS 5 BP 936 EP 939 DI 10.1103/PhysRevLett.77.936 PG 4 WC Physics, Multidisciplinary SC Physics GA UY952 UT WOS:A1996UY95200037 ER PT J AU Newman, DE Carreras, BA Diamond, PH AF Newman, DE Carreras, BA Diamond, PH TI The dynamics of sandpiles with a sheared flow SO PHYSICS LETTERS A LA English DT Article ID AVALANCHES AB Sheared wind on a sandpile model produces a decorrelation of transport events and eliminates events with scale lengths on the order of the box size. The effective diffusion coefficient changes its asymptotic behavior from D-eff alpha x(alpha), with alpha close to 1, to D-eff alpha x(0). These asymptotic limits are consistent with analytical calculations based on the Burgers equation and have implications for SOC theory as a paradigm for turbulent transport. C1 UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. RP Newman, DE (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 8 TC 19 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JUL 29 PY 1996 VL 218 IS 1-2 BP 58 EP 63 DI 10.1016/0375-9601(96)00359-3 PG 6 WC Physics, Multidisciplinary SC Physics GA UX646 UT WOS:A1996UX64600010 ER PT J AU Lee, YJ Galoforo, SS Berns, CM Blackburn, RV Huberman, E Corry, PM AF Lee, YJ Galoforo, SS Berns, CM Blackburn, RV Huberman, E Corry, PM TI Dual effect of 1 alpha,25-dihydroxyvitamin D-3 on hsp28 and PKC beta gene expression in phorbol ester-resistant human myeloid HL-525 leukemic cells SO BIOCHEMICAL PHARMACOLOGY LA English DT Article DE 1 alpha,25-dihydroxyvitamin D-3; HL-525; hsp28; PKC beta ID HEAT-SHOCK ELEMENT; PROTEIN KINASE-C; CHINESE-HAMSTER-CELLS; TUMOR NECROSIS FACTOR; 1,25-DIHYDROXYVITAMIN-D3 RECEPTOR; TRANSCRIPTIONAL ACTIVATION; INDUCED DIFFERENTIATION; STRESS PROTEINS; BINDING-PROTEIN; MESSENGER-RNA AB We investigated the effect of 1 alpha-25-dihydroxyvitamin D-3 [1,25-(OH)(2)D-3] on the expression of the 28-kDa heat shock protein gene (hsp28) and the protein kinase C beta gene (PKC beta) in the human myeloid HL-60 leukemic cell variant HL-525, which is resistant to phorbol ester-induced macrophage differentiation. Northern and western blot analysis showed little or no hsp28 gene expression in the HL-60 cell variant, HL-205, which is susceptible to such differentiation, while a relatively high basal level of hsp28 gene expression was observed in the HL-525 cells. However, both cell lines demonstrated heat shock-induced expression of this gene. During treatment with 50-300 nM 1,25-(OH)(2)D-3, a marked reduction of hsp28 gene expression along with an induction of PKC beta gene expression was observed in HL-525 cells. A gel mobility-shift assay demonstrated that the 1,25-(OH)(2)D-3-induced alteration of hsp28 gene expression was associated with decreased binding activity to the vitamin D-3 receptor-vitamin D-3 response element (VDR-VDRE), whereas binding to the heat shock transcription factor-heat shock element (HSF-HSE) was not altered. Our results suggest that the dual effect of 1,25-(OH)(2)D-3 on hsp28 and PKC beta gene expression is due to the different sequence composition of the vitamin D response element in the promoter region as well as an accessory factor for each gene or that 1,25-(OH)(2)D-3 increases PKC beta gene expression, which, in turn, negatively regulates the expression of the hsp28 gene or vice versa. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. RP Lee, YJ (reprint author), WILLIAM BEAUMONT HOSP,DEPT RADIAT ONCOL,RES LABS,3601 W 13 MILE RD,ROYAL OAK,MI 48073, USA. FU NCI NIH HHS [CA48000, CA44550] NR 45 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0006-2952 J9 BIOCHEM PHARMACOL JI Biochem. Pharmacol. PD JUL 26 PY 1996 VL 52 IS 2 BP 311 EP 319 DI 10.1016/0006-2952(96)00209-2 PG 9 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA UU383 UT WOS:A1996UU38300016 PM 8694856 ER PT J AU Chen, XY Kang, HS Shen, LX Chamorro, M Varmus, HE Tinoco, I AF Chen, XY Kang, HS Shen, LX Chamorro, M Varmus, HE Tinoco, I TI A characteristic bent conformation of RNA pseudoknots promotes -1 frameshifting during translation of retroviral RNA SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE RNA; pseudoknot; NMR; frameshifting; retroviruses ID IDENTIFICATION; SIGNAL; VIRUS AB The structures of four different RNA pseudoknots that provide one of the signals required for ribosomal frameshifting in mouse mammary tumor virus have been determined by NMR. The RNA pseudoknots have similar sequences and assume similar secondary structures, but show significantly different frameshifting efficiencies. The three-dimensional structures of one frameshifting and one non-frameshifting RNA pseudoknot had been determined previously by our group. Here we determine the structures of two new RNA pseudoknots, and relate the structures of all four pseudoknots to their frameshifting abilities. The two efficient frameshifting pseudoknots adopt characteristic bent conformations with stem 1 bending towards the major groove of stem 2. In contrast, the two poor frameshifting pseudoknots have structures very different from each other and from the efficient frameshifters. One has linear, coaxially stacked stems, the other has stems twisted and bent, but in the opposite direction to the efficient frameshifters. Changes in loop size that favor bending (shorter loops) increase frameshifting efficiency; longer loops that allow linear arrangement of the stems decrease frameshifting. Frameshifting pseudoknots in feline immunodeficiency virus and simian retrovirus have different loop sequences, but the sequences at their stem junctions imply the same bent conformation as in the mouse mammary tumor viral RNA. The requirement for a precise pseudoknot conformation for efficient frameshifting strongly implies that a specific interaction occurs between the viral RNA pseudoknot and the host protein-synthesizing machinery. (C) 1996 Academic Press Limited C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV BIOL STRUCT,BERKELEY,CA 94720. SRI INT,DIV LIFE SCI,MENLO PK,CA 94025. UNIV CALIF SANTA CRUZ,SINSHEIMER LABS,SANTA CRUZ,CA 95064. NCI,NIH,BETHESDA,MD 20892. FU NCI NIH HHS [CA12705]; NIGMS NIH HHS [GM10840] NR 14 TC 83 Z9 85 U1 0 U2 5 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JUL 26 PY 1996 VL 260 IS 4 BP 479 EP 483 DI 10.1006/jmbi.1996.0415 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UY986 UT WOS:A1996UY98600001 PM 8759314 ER PT J AU Altschuler, EL Lades, M Stong, R AF Altschuler, EL Lades, M Stong, R TI Finding Hamiltonian cycles SO SCIENCE LA English DT Letter C1 RICE UNIV,DEPT MATH,HOUSTON,TX 77005. RP Altschuler, EL (reprint author), LAWRENCE LIVERMORE NATL LAB,INST SCI COMP RES,LIVERMORE,CA 94551, USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUL 26 PY 1996 VL 273 IS 5274 BP 413 EP 414 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UY983 UT WOS:A1996UY98300004 ER PT J AU Thorn, RP Monks, PS Stief, LJ Kuo, SC Zhang, ZY Klemm, RB AF Thorn, RP Monks, PS Stief, LJ Kuo, SC Zhang, ZY Klemm, RB TI Photoionization efficiency spectrum, ionization energy, and heat, of formation of Br2O SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID HOBR; THERMOCHEMISTRY; RADICALS; BROMINE; BRO AB The photoionization efficiency (PIE) spectrum of Br2O was measured over the wavelength range lambda = 100-125 nm by using a photoionization mass spectrometer apparatus coupled to a synchrotron radiation source. A value of 10.26(4) +/- 0.01(1) eV was obtained for the adiabatic ionization energy of Br2O from analysis of the photoionization thresholds. Also, the appearance energy (AE) of BrO+ (from the dissociative ionization of Br2O) was determined from the PIE spectrum of BrO+ over the wavelength range lambda = 104-110 nm. Combining the AE(298) value, 11.71(4) +/- 0.01(4) eV, with known thermodynamic quantities yields a value for Delta(f)H degrees(298)(Br2O) = 107.1 +/- 3.5 kJ mol(-1). The value for Delta(f)H degrees(298)(Br2O) may be related to Delta(f)H degrees(298)(HOBr) through the equilibrium constant for the reaction Br2O + H2O reversible arrow 2HOBr. This leads to Delta(f)H degrees(298)(HOBr) = -60.0 +/- 3.5 kJ mol(-1). C1 NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RI Monks, Paul/H-6468-2016 OI Monks, Paul/0000-0001-9984-4390 NR 30 TC 29 Z9 29 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 25 PY 1996 VL 100 IS 30 BP 12199 EP 12203 PG 5 WC Chemistry, Physical SC Chemistry GA UY938 UT WOS:A1996UY93800012 ER PT J AU Smirnov, SN Braun, CL Greenfield, SR Svec, WA Wasielewski, MR AF Smirnov, SN Braun, CL Greenfield, SR Svec, WA Wasielewski, MR TI Giant dipole moment in a triad system. Mechanisms of anisotropic photoresponse in the transient dc conductivity of dipolar solutes SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ELECTRON-TRANSFER; CURRENTS; LIQUIDS AB A transient de conductivity method was used to observe formation of a giant dipole moment for the triad molecule MA-ANI-NI (methoxyaniline-aminonaphthalimide-dimethylphenyl-naphthalenediimide-octyl) in toluene. The independence of the dipole moment on excitation wavelength indicates high efficiency of intramolecular energy or (and) electron transfer. The effect of light polarization on the DC conductivity signal caused by a photoinduced increase in solute dipole moment is considered in detail. It is shown that the time variation of the signal includes information about structural anomalies in the angular distribution function of molecular dipoles and depends on light polarization even for zero ground state dipole moment. Nonzero ground state dipole moment and (or) electric field dependence of the charge transfer rate constants give an additional source for an anisotropic photoresponse signal. Analysis of the photoresponse and its anisotropy for the triad gives ground (mu g), first (mu(1)), and second (mu(2)) excited state dipole moments as follows: mu(g) = 12 +/- 5 D, mu(1) = 35 +/- 10, and mu(2) = 87 +/- 6 D. The lifetime of the giant dipole state is tau = 290 +/- 10 ns, and the molecule's rotational time is tau(r) = 1.6 +/- 0.15 ns. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. RP Smirnov, SN (reprint author), DARTMOUTH COLL,DEPT CHEM,HANOVER,NH 03755, USA. RI Smirnov, Sergei/H-8774-2016 NR 15 TC 15 Z9 15 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 25 PY 1996 VL 100 IS 30 BP 12329 EP 12336 DI 10.1021/jp960171j PG 8 WC Chemistry, Physical SC Chemistry GA UY938 UT WOS:A1996UY93800029 ER PT J AU Yang, MX Eng, J Kash, PW Flynn, GW Bent, BE Holbrook, MT Bare, SR Gland, JL Fischer, DA AF Yang, MX Eng, J Kash, PW Flynn, GW Bent, BE Holbrook, MT Bare, SR Gland, JL Fischer, DA TI Generation and reaction of vinyl groups on a Cu(100) surface SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ABSORPTION FINE-STRUCTURE; ENERGY-LOSS SPECTRA; BOND LENGTHS; SHAPE RESONANCES; METAL-SURFACES; ETHYLENE; NI(100); AG(111); DECOMPOSITION; ETHYLIDYNE AB The adsorption and reactions of vinyl bromide and vinyl iodide on a Cu(100) surface have been studied by temperature-programmed desorption in conjunction with near-edge X-ray absorption fine structure (NEXAFS) and work function change measurements. Vinyl bromide adsorbs molecularly on the surface at 100 K. The polarization dependence of the pi*(c=c) resonance indicates that the molecules lie with their pi bond within 28 +/- 5 degrees of parallel to the surface. Upon healing, both vinyl bromide and vinyl iodide decompose to generate surface vinyl groups, which adopt a tilted orientation on the surface. Both the molecular halides and the surface vinyl groups show a splitting of the pi*(c=c) NEXAFS resonance due to the inequivalence of the carbon atoms in these species. The position of the sigma*(c-c) shape resonances for these species indicates little change (<0.05 Angstrom) in C=C bond length due to adsorption and dissociation to form vinyl groups. Chemical displacement studies show that the C-Br bond cleavage in vinyl bromide occurs at 160 K. This dissociation temperature is confirmed by complementary NEXAFS and work function change measurement results. At 250 K, vinyl groups couple to yield 1,3-butadiene with 100% selectivity. C1 COLUMBIA UNIV,DEPT CHEM,NEW YORK,NY 10027. COLUMBIA UNIV,COLUMBIA RADIAT LAB,NEW YORK,NY 10027. DOW CHEM CO USA,MIDLAND,MI 48674. UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. NR 47 TC 24 Z9 24 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 25 PY 1996 VL 100 IS 30 BP 12431 EP 12439 DI 10.1021/jp952386j PG 9 WC Chemistry, Physical SC Chemistry GA UY938 UT WOS:A1996UY93800045 ER PT J AU Ahn, DJ Berman, A Charych, D AF Ahn, DJ Berman, A Charych, D TI Probing the dynamics of template-directed calcite crystalization with in situ FTIR SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID AIR-WATER-INTERFACE; LANGMUIR-BLODGETT-FILMS; REFLECTION-ABSORPTION SPECTROMETRY; X-RAY-DIFFRACTION; INFRARED SPECTROSCOPIC ANALYSIS; MONOLAYER FILMS; ORIENTED CRYSTALLIZATION; COMPRESSED MONOLAYERS; ELECTRON-DIFFRACTION; ACID MONOLAYERS AB Organic template-directed mineralization of calcite crystals has been probed in situ by external reflection-absorption FTIR spectroscopy in an effort to understand the dynamics of the organic-inorganic interface during crystal growth. The main focus is to elucidate structural changes that may occur in the organic template as crystal growth progresses. The nucleation face types of calcite were visually identified according to known crystal morphologies and by the corresponding carbonate stretching and deformation vibrational bands. Structural reorganization occurring in the organic template could be observed by intensity variations and frequency shifts in the methylene stretching bands of octadecanoic acid, octadecyl sulfate, and acidic polydiacetylenic lipid film, These organic templates nucleated calcite at the (010), (001), and (012) planes, respectively. The surfactant thin films uniquely adapt themselves in order to optimize the geometrical and stereochemical fit to the growing calcite crystals. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. RI Berman, Amir/F-1870-2012 NR 51 TC 57 Z9 57 U1 2 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 25 PY 1996 VL 100 IS 30 BP 12455 EP 12461 DI 10.1021/jp953536t PG 7 WC Chemistry, Physical SC Chemistry GA UY938 UT WOS:A1996UY93800048 ER PT J AU Zurek, WH AF Zurek, WH TI Cosmology - The shards of broken symmetry SO NATURE LA English DT Editorial Material ID STRINGS RP Zurek, WH (reprint author), LOS ALAMOS NATL LAB, THEORET ASTROPHYS GRP, POB 1663, LOS ALAMOS, NM 87545 USA. NR 10 TC 26 Z9 27 U1 0 U2 2 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUL 25 PY 1996 VL 382 IS 6589 BP 296 EP 298 DI 10.1038/382296a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UY950 UT WOS:A1996UY95000021 ER PT J AU Ruutu, VMH Eltsov, VB Gill, AJ Kibble, TWB Krusius, M Makhlin, YG Placais, B Volovik, GE Xu, W AF Ruutu, VMH Eltsov, VB Gill, AJ Kibble, TWB Krusius, M Makhlin, YG Placais, B Volovik, GE Xu, W TI Vortex formation in neutron-irradiated superfluid He-3 as an analogue of cosmological defect formation SO NATURE LA English DT Article ID COSMIC STRINGS; LIQUID-CRYSTALS AB TOPOLOGICAL defects formed during a rapid symmetry-breaking phase transition in the early Universe(1,2) could be responsible for seeding large-scale structure, for the anisotropy of the microwave background radiation, and for the predominance of matter over antimatter(3,4). The theory describing this cosmological phase transition is formally analogous to that describing the transition to the superfluid state in liquid He-3, so that in principle the process of cosmological defect formation can be modelled in the laboratory. Here we report the results of an experiment in which the 'primordial fireball' is mimicked using a neutron-induced nuclear reaction (n + He-3 --> p + He-3 + 0.76 MeV) to heat small regions of superfluid He-3 above the superfluid transition temperature. These bubbles of normal liquid cool extremely rapidly, and we find that their transition back to the superfluid state is accompanied the formation of a random network of vortices (the superfluid analogue of cosmic strings). We monitor the evolution of this defect state by rotating the superfluid sample, allowing vortices to escape from the network and thus be probed individually. Our results provide clear confirmation of the idea that topological defects form at a rapid second-order phase transition, and give quantitative support to the Kibble-Zurek mechanism(5,6) of cosmological defect formation. C1 HELSINKI UNIV TECHNOL, LOW TEMP LAB, SF-02150 ESPOO, FINLAND. PL KAPITZA PHYS PROBLEMS INST, MOSCOW 117334, RUSSIA. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND. LOS ALAMOS NATL LAB, DIV THEORET T6, LOS ALAMOS, NM 87545 USA. LD LANDAU THEORET PHYS INST, MOSCOW 117334, RUSSIA. ECOLE NORMALE SUPER, PHYS MAT CONDENSEE LAB, CNR, URA 1437, F-75231 PARIS 05, FRANCE. RI Volovik, Grigory/F-6396-2015; Eltsov, Vladimir/M-8767-2015; Placais, Bernard/E-3014-2016 OI Eltsov, Vladimir/0000-0002-6949-5334; Placais, Bernard/0000-0003-2408-7393 NR 17 TC 301 Z9 302 U1 2 U2 15 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUL 25 PY 1996 VL 382 IS 6589 BP 334 EP 336 DI 10.1038/382334a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UY950 UT WOS:A1996UY95000044 ER PT J AU Boller, A Okazaki, I Wunderlich, B AF Boller, A Okazaki, I Wunderlich, B TI Modulated differential scanning calorimetry in the glass transition region .3. Evaluation of polystyrene and poly(ethylene tetrephthalate) SO THERMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT 24th North-American-Thermal-Analysis-Society Conference CY SEP 10-13, 1995 CL SAN FRANCISCO, CA SP N Amer Thermal Anal Soc DE activation energy; glass transition; heat capacity; heat how calorimeter; MDSC; modulated calorimetry; poly(ethylene terephthalate); polystyrene; thermodynamics ID TEMPERATURE AB Modulated differential scanning calorimetry (MDSC)) presents a new method to evaluate the kinetics underlying the glass transition. Equations that were derived earlier to describe the various time effects in the glass transition, based on irreversible thermodynamics and the theory of liquids, are applied to quasi-isothermal MDSC experiments on amorphous polystyrene and poly(ethylene terephthalate). The analysis involves the computation of a phase angle for the change in the apparent heat capacity at the glass transition that becomes 60 degrees at the point of half-vitrification, followed by a determination of the activation energy as a function of modulation amplitude. Activation energies of 346 and 328 kJ mol(-1) were found for the respective polymers. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Boller, A (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 22 TC 38 Z9 39 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD JUL 25 PY 1996 VL 284 IS 1 BP 1 EP 19 DI 10.1016/0040-6031(96)02865-1 PG 19 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA VC198 UT WOS:A1996VC19800002 ER PT J AU Lyon, WS AF Lyon, WS TI DRAGNET-ORNL style SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-LETTERS LA English DT Article RP Lyon, WS (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 0236-5731 J9 J RADIOAN NUCL CH LE JI J. Radioanal. Nucl. Chem.-Lett. PD JUL 24 PY 1996 VL 213 IS 5 BP 311 EP 316 DI 10.1007/BF02162930 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA VH964 UT WOS:A1996VH96400001 ER PT J AU Sun, H Blatter, F Frei, H AF Sun, H Blatter, F Frei, H TI Cyclohexanone from cyclohexane and O-2 in a zeolite under visible light with complete selectivity SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ELECTRIC-FIELD; METHANE MOLECULE; AIR-OXIDATION; RED-LIGHT; ALKANES; BAND; PHOTOOXIDATION; IRRADIATION; DIFFRACTION; DIOXYGEN AB Irradiation of a cyclohexane and O-2-loaded zeolite NaY with green or blue light resulted in oxidation of the alkane to cyclohexyl hydroperoxide and cyclohexanone (plus water) as the sole products. The hydroperoxide was found to rearrange thermally to cyclohexanone without side reaction. Complete selectivity in terms of the final oxidation product cyclohexanone persists even at high (>40%) conversion of cyclohexane. The chemistry was monitored by in-situ FT-infrared spectroscopy and the visible reactant absorption by diffuse reflectance spectroscopy. The absorption is attributed to the cyclohexane O-2 charge-transfer transition, which is shifted from the UV into the visible by the very high electrostatic field of the zeolite matrix cage. At elevated temperature, cyclohexane is thermally oxidized by O-2 to the same products. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, CHEM BIODYNAM LAB, MS CALVIN LAB, BERKELEY, CA 94720 USA. NR 67 TC 100 Z9 107 U1 1 U2 15 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 JUL 24 PY 1996 VL 118 IS 29 BP 6873 EP 6879 DI 10.1021/ja953273g PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA UY871 UT WOS:A1996UY87100009 ER PT J AU Stocking, EM SanzCervera, JF Williams, RM Unkefer, CJ AF Stocking, EM SanzCervera, JF Williams, RM Unkefer, CJ TI Studies on the biosynthesis of paraherquamide A. Origin of the beta-methylproline ring SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CHEMICAL MODIFICATION; BREVIANAMIDE-B; PENICILLIUM-CHARLESII; ANTHELMINTIC ACTIVITY; ANTIPARASITIC AGENTS C1 COLORADO STATE UNIV,DEPT CHEM,FT COLLINS,CO 80523. LOS ALAMOS NATL LAB,NIH STABLE ISOTOPE RESOURCE,LOS ALAMOS,NM 87545. NR 27 TC 25 Z9 25 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 24 PY 1996 VL 118 IS 29 BP 7008 EP 7009 DI 10.1021/ja961322z PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA UY871 UT WOS:A1996UY87100029 ER PT J AU Benevides, JM Terwilliger, TC Vohnik, S Thomas, GJ AF Benevides, JM Terwilliger, TC Vohnik, S Thomas, GJ TI Raman spectroscopy of the Ff gene V protein and complexes with poly(dA): Nonspecific DNA recognition and binding SO BIOCHEMISTRY LA English DT Article ID GVP-SSDNA COMPLEX; TURN-HELIX MOTIF; MODEL COMPOUNDS; SULFHYDRYL INTERACTIONS; CYSTEINE CONFORMATION; NUCLEIC-ACIDS; FD; M13; BACTERIOPHAGE-M13; SCATTERING AB Raman spectra of crystals and solutions of the single-stranded DNA binding protein of bacteriophage Ff (gene V protein, gVp) and of solution complexes of gVp with single-stranded poly(deoxyadenylic acid) [poly(dA)] reveal the following: (i) The gVp secondary and tertiary structures are similar in solution and in the crystal and are dominated by beta-sheet domains, in agreement with NMR and X-ray findings, (ii) Subunit conformation and side chain environments of gVp are virtually unchanged over a wide range of salt concentration (0 < [NaCl] < 100 mM); however, the solution conformation of poly(dA) exhibits sensitivity to added salt. The perturbed Raman markers indicate subtle changes in helix backbone geometry with accompanying small differences in base stacking as the concentration of NaCl is changed. (iii) In complexes with poly(dA), neither the conformation of gVp nor its side chain environments are altered significantly in comparison to the free protein, This is the case at both high salt (nucleotide-to-subunit binding stoichiometry n = 4) and low salt (n = 3). (iv) The Raman signature of poly(dA) undergoes small perturbations upon gVp binding, indicative of small changes in base stacking and phosphodiester backbone conformation. The present results show that the different stoichiometric binding modes of gVp to poly(dA) are accomplished without significant changes in gVp subunit structure and with only modest changes in the single-stranded poly(dA) ligand. This contrasts sharply with sequence-specific double-stranded DNA binding proteins, such as the phage lambda and D108 repressors, which undergo substantial structural changes upon DNA binding, and which also alter more dramatically the Raman fingerprints of their DNA target sites. Thus, nonspecific and specific nucleic acid recognition modes are distinguishable by Raman spectroscopy. The Raman signature of gVp also allows examination of hydrogen bonding interactions of unique side chains within the hydrophobic core (cysteine 33) and at the binding interface (tyrosine 41). These are discussed in relation to the recently published gVp crystal structure. C1 UNIV MISSOURI,SCH BIOL SCI,DIV CELL BIOL & BIOPHYS,KANSAS CITY,MO 64110. LOS ALAMOS NATL LAB,STRUCT BIOL GRP,LOS ALAMOS,NM 87545. RI Terwilliger, Thomas/K-4109-2012 OI Terwilliger, Thomas/0000-0001-6384-0320 FU NIGMS NIH HHS [GM50776] NR 28 TC 18 Z9 19 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 23 PY 1996 VL 35 IS 29 BP 9603 EP 9609 DI 10.1021/bi952602e PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UY834 UT WOS:A1996UY83400035 PM 8755742 ER PT J AU Jamison, GM Saunders, RS Wheeler, DR Alam, TM McClain, MD Loy, DA Ziller, JW AF Jamison, GM Saunders, RS Wheeler, DR Alam, TM McClain, MD Loy, DA Ziller, JW TI Isolation and characterization of the molybdenum alkylidyne complex [(F3C)Me(2)CO]Mo-2(C-t-Bu)[N(Ar)P=C(H)(CMe(2)Ph)] and its conversion to a phosphamolybdacyclobutene SO ORGANOMETALLICS LA English DT Article ID COORDINATED PHOSPHORUS-COMPOUNDS; TRANSITION-METALS; PHOSPHAALKYNES; METATHESIS; TUNGSTEN; BONDS; CHEMISTRY AB Novel molybdenum alkylidyne [(F3C)Me(2)-CO]Mo-2(C-t-Bu)[N(Ar)P=C(H)(CMe(2)Ph)] (Ar = 2,6-(i-Pr)(2)C6H3; 3b) is formed in the reaction of tert-butylphosphaalkyne 2 with molybdenum alkylidene 1b. Alkylidyne 3b, which contains a formal (phosphaalkenyl)amido ligand, rearranges quantitatively at elevated temperature to form the alkoxide-shifted phosphamolybdacyclobutene 4b. Complexes 3b and 4b have been fully characterized by spectroscopic and X-ray crystallographic analysis; cleavage of the P=C-t-Bu triple bond in complex 3b is confirmed. C1 UNIV CALIF IRVINE,DEPT CHEM,IRVINE,CA 92717. RP Jamison, GM (reprint author), SANDIA NATL LABS,ORG 1812,POB 5800,MS 1407,ALBUQUERQUE,NM 87185, USA. RI Loy, Douglas/D-4847-2009 OI Loy, Douglas/0000-0001-7635-9958 NR 31 TC 9 Z9 9 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD JUL 23 PY 1996 VL 15 IS 15 BP 3244 EP 3246 DI 10.1021/om960418z PG 3 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA UZ016 UT WOS:A1996UZ01600002 ER PT J AU Wander, SA Miedaner, A Noll, BC Barkley, RM DuBois, DL AF Wander, SA Miedaner, A Noll, BC Barkley, RM DuBois, DL TI Chelate bite effects for [Pd(triphosphine)(solvent)](BF4)(2) in electrochemical CO2 reduction and the heterolytic cleavage of molecular hydrogen SO ORGANOMETALLICS LA English DT Article ID X-RAY CRYSTAL; RHODIUM-CATALYZED HYDROFORMYLATION; WATER GAS SHIFT; PALLADIUM COMPLEXES; (BF4)(2) COMPLEXES; LINEAR OLIGOPHOSPHAALKANES; DIPHOSPHINE LIGANDS; HYDRIDE COMPLEXES; CARBON-MONOXIDE; REACTIVITY AB A series of [Pd(triphosphine)(CH3CN)](BF4)(2) complexes has been prepared with different chelate bites, Stoichiometric reactions of these complexes with triethylphosphine, NaBH4, and H-2 have been studied, as well as the catalytic electrochemical reduction of CO2. AU of these reactions show significant chelate effects. [Pd(ttpE)(CH3CN)](BF4)(2) (where ttpE is bis(3-(diethylphosphino)propyl)phenylphosphine catalyzes the electrochemical reduction of CO2 to CO in acidic dimethylformamide solutions and reacts with NaBH4 or H-2 to form [Pd(ttpE)(H)](BF4). The latter complex is the decomposition product formed under catalytic conditions. X-ray diffraction studies of [Pd(ttpE)(CH3CN)]CBF4)(2) and [Pd(tpE)(H)](BF4) provide insight into possible steric origins of reactivity differences between the last two complexes and analogous complexes with smaller cheIate bites. [Pd(fttpE)(CH3CN)](BF4)(2) has a square-planar structure with one methylene group of the ethyl subtituents making a close contact with the nitrogen atom of acetonitrile. This steric interaction likely contributes to some of the reactitrity differences observed. [Pd(ttpE)(H)](BF4) also has a square-planar structure with the two terminal phosphol-us atoms of the triphosphine ligand distorted slightly toward the hydride ligand. Extended Hiickel molecular orbital calculations suggest thatsmall ckelate bites shift electrondensity onto the hydride ligand, making it more hydridic, while larger chelate bites shift electron density away from the hydride ligand, making it more acidic. C1 NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. NR 74 TC 27 Z9 27 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD JUL 23 PY 1996 VL 15 IS 15 BP 3360 EP 3373 DI 10.1021/om960072s PG 14 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA UZ016 UT WOS:A1996UZ01600020 ER PT J AU Mahan, GD Sofo, JO AF Mahan, GD Sofo, JO TI The best thermoelectric SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID KONDO RESONANCE; YBAL3; PHOTOEMISSION AB What electronic structure provides the largest figure of merit for thermoelectric materials? To answer that question, we write the electrical conductivity, thermopower, and thermal conductivity as integrals of a single function, the transport distribution, Then we derive the mathematical function for the transport distribution, which gives the largest figure of merit, A delta-shaped transport distribution is found to maximize the thermoelectric properties, This result indicates that a narrow distribution of the energy of the electrons participating in the transport process is needed for maximum thermoelectric efficiency, Some possible realizations of this idea are discussed. C1 OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. CTR ATOM BARILOCHE, INST BALSEIRO, RA-8400 SAN CARLOS BARILO, RIO NEGRO, ARGENTINA. RP UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. RI Sofo, Jorge/J-4415-2012; Sofo, Jorge/B-4344-2014 OI Sofo, Jorge/0000-0003-4513-3694; Sofo, Jorge/0000-0003-4513-3694 NR 16 TC 670 Z9 677 U1 20 U2 206 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 JUL 23 PY 1996 VL 93 IS 15 BP 7436 EP 7439 DI 10.1073/pnas.93.15.7436 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UY930 UT WOS:A1996UY93000003 PM 11607692 ER PT J AU Allerman, AA Biefeld, RM Kurtz, SR AF Allerman, AA Biefeld, RM Kurtz, SR TI InAsSb-based mid-infrared lasers (3.8-3.9 mu m) and light-emitting diodes with AlAsSb claddings and semimetal electron injection, grown by metalorganic chemical vapor deposition SO APPLIED PHYSICS LETTERS LA English DT Article AB Gain-guided, injection lasers using AlAsSb for optical confinement and a strained InAsSb/InAs multiquantum well active region were grown by metalorganic chemical vapor deposition. The semi-metal properties of a p-GaAsSb/n-InAs heterojunction are utilized as a source for injection of electrons into the active region of the laser. In pulsed mode, the laser operated up to 210 K with an emission wavelength of 3.8-3.9 mu m. We also report on the two-color emission of alight-emitting diode with two different active regions to demonstrate multistage operation of these ''unipolar'' devices. (C) 1996 American Institute of Physics. RP Allerman, AA (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 10 TC 53 Z9 54 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 22 PY 1996 VL 69 IS 4 BP 465 EP 467 DI 10.1063/1.118141 PG 3 WC Physics, Applied SC Physics GA WB364 UT WOS:A1996WB36400009 ER PT J AU Chang, JJ Warner, BE AF Chang, JJ Warner, BE TI Laser-plasma interaction during visible-laser ablation of methods SO APPLIED PHYSICS LETTERS LA English DT Article AB We have investigated the dynamics of high-radiance visible-laser interaction with a metal vapor plasma during laser ablation of aluminum and carbon steel. The experiment with a copper vapor laser reveals strong plasma-absorption induced ignition at laser intensities above 1-2 GW/cm(-2). Approximation based on hydrodynamic relations indicates that the vapor density at the end of the 40-ns laser pulse is 3 X 10(20)-1 X 10(21) cm(-3) with a pressure of a few thousand atmosphere at the target surface. This high-density vapor with a temperature exceeding 10 000 K leads to pronounced plasma absorption via photoionization. Plasma absorption via inverse bremsstrahlung is determined to be negligible because of a relatively low electron density, measured to be peaked at similar to 5 x 10(18) cm(-3). RP Chang, JJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,M-S L-463,LIVERMORE,CA 94551, USA. NR 10 TC 117 Z9 120 U1 0 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 22 PY 1996 VL 69 IS 4 BP 473 EP 475 DI 10.1063/1.118144 PG 3 WC Physics, Applied SC Physics GA WB364 UT WOS:A1996WB36400012 ER PT J AU Zolper, JC Rieger, DJ Baca, AG Pearton, SJ Lee, JW Stall, RA AF Zolper, JC Rieger, DJ Baca, AG Pearton, SJ Lee, JW Stall, RA TI Sputtered AlN encapsulant for high-temperature annealing of GaN SO APPLIED PHYSICS LETTERS LA English DT Article ID DEVICES AB Reactively sputtered AlN is shown by electrical characterization of Pt/Au Schottky diodes to be an effect encapsulant for GaN annealed at 1100 degrees C. Schottky diodes formed on GaN encapsulated with AIN during the anneal had low reverse leakage currents with breakdown voltages in excess of 40 V. In contrast, samples annealed without the AlN layer had 3-4 orders-of-magnitude higher reverse leakage currents. Atomic force microscopy images of as-grown and annealed samples also demonstrate an increase in surface roughness and a change in morphology of the uncapped samples following annealing. Auger electron spectroscopy supports the hypothesis that the AlN encapsulant is reducing N loss from the GaN substrate. N toss in the uncapped samples is expected to create an n(+)-region at the surface that accounts for the high reverse leakage current and improved Ohmic behavior for the uncapped samples. The use of AlN encapsulation will enable the realization of all ion implanted GaN metal semiconductor field effect transistors. (C) 1996 American Institute of Physics. C1 UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611. EMCORE CORP,SOMERSET,NJ 08873. RP Zolper, JC (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 18 TC 63 Z9 63 U1 1 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 22 PY 1996 VL 69 IS 4 BP 538 EP 540 DI 10.1063/1.117779 PG 3 WC Physics, Applied SC Physics GA WB364 UT WOS:A1996WB36400034 ER PT J AU Coffman, FL Cao, R Pianetta, PA Kapoor, S Kelly, M Terminello, LJ AF Coffman, FL Cao, R Pianetta, PA Kapoor, S Kelly, M Terminello, LJ TI Near-edge x-ray absorption of carbon materials for determining bond hybridization In mixed sp2/sp3 bonded materials SO APPLIED PHYSICS LETTERS LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; DIAMOND AB Near-edge x-ray absorption fine structure (NEXAFS) measurements were performed on a variety of carbon materials, covering a range of hybrid bonding character from pure sp3 type to pure sp2 type. Diamond, chemical vapor deposited (CVD) diamond films of varying quality. Diamond-like carbon (DLC) films. and graphite were examined with this technique and these measurements were compared with Raman spectroscopy results and scanning electron microscopy images of carbon film morphology. For the mixed sp2 and sp3 bonded DLC materials, NEXAFS does not suffer from tile large Raman cross-section difference between sp2 and sp3 type bonds, thus allowing unambiguous characterization of carbon thin films with a broader range of sp2/sp3 bonding ratios than possible with Raman spectroscopy alone. This capability was used to determine the transition point where the sequential-CVD carbon film growth technique produces predominately sp3 or sp2 bonded material. (C) 1996 American Institute of Physics. C1 STANFORD UNIV,STANFORD,CA 94309. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Coffman, FL (reprint author), STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309, USA. NR 10 TC 115 Z9 116 U1 4 U2 41 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 22 PY 1996 VL 69 IS 4 BP 568 EP 570 DI 10.1063/1.117789 PG 3 WC Physics, Applied SC Physics GA WB364 UT WOS:A1996WB36400044 ER PT J AU Wang, YL Bian, W Zhu, Y Cai, ZX Welch, DO Sabatini, RL Suenaga, M Thurston, TR AF Wang, YL Bian, W Zhu, Y Cai, ZX Welch, DO Sabatini, RL Suenaga, M Thurston, TR TI A kinetic mechanism for the formation of aligned (Bi,Pb)(2)Sr2Ca2Cu3O10 in a powder-in-tube processed tape SO APPLIED PHYSICS LETTERS LA English DT Article ID PHASE; BI2SR2CA2CU3O10+DELTA; TRANSFORMATION; GROWTH AB A two-step process is proposed for the Formation of c-axis aligned (Bi,Pb)(2)Sr2Ca2Cu3O10+delta [Bi(2:2:2:3)] platelets in a silver sheath. The process involves: (1) the formation of c-axis aligned (Bi,Pb)(2)Sr2CaCu2O8+delta at early stage of hear treatment and (2) the subsequent intercalation of Ca-Cu-O layers to form Bi(2:2:2:3). This is based on the measurements of (1) the rocking curves for c-axis alignment and the two theta scans for the Bi(2:2:2:3) conversion ratio, both by a transmission x-ray technique, and (2) a quantitative study of the phase conversion due to intercalation of Ca-Cu-O layers into existing Bi(2:2:1:2) by transmission electron microscopy. (C) 1996 American Institute of Physics. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Wang, YL (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 17 TC 56 Z9 56 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 22 PY 1996 VL 69 IS 4 BP 580 EP 582 DI 10.1063/1.117759 PG 3 WC Physics, Applied SC Physics GA WB364 UT WOS:A1996WB36400048 ER PT J AU Whitehead, J AF Whitehead, J TI Reusability in forefront SO AVIATION WEEK & SPACE TECHNOLOGY LA English DT Letter RP Whitehead, J (reprint author), LAWRENCE LIVERMORE NATL LAB,PHYS & SPACE TECHNOL DIRECTORATE,LIVERMORE,CA, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 SN 0005-2175 J9 AVIAT WEEK SPACE TEC JI Aviat. Week Space Technol. PD JUL 22 PY 1996 VL 145 IS 4 BP 6 EP 6 PG 1 WC Engineering, Aerospace SC Engineering GA UY082 UT WOS:A1996UY08200005 ER PT J AU Alm, T Ropke, G Sedrakian, A Weber, F AF Alm, T Ropke, G Sedrakian, A Weber, F TI D-3(2) pairing in asymmetric nuclear matter SO NUCLEAR PHYSICS A LA English DT Article DE BCS pairing; isospin asymmetry; neutron stars ID NEUTRON-STARS; SUPERFLUIDITY; SYSTEMS AB The superfluid D-3(2) pairing instability in isospin-asymmetric nuclear matter is studied, using the Paris nucleon-nucleon interaction as an input. It is found that the critical temperature associated with the transition to the superfluid phase becomes strongly suppressed with increasing isospin asymmetry, and vanishes for asymmetry parameter values alpha (= (n(n) - n(p))/(n(n) + n(p))) that are larger than several percent. It is shown that for neutron star models based on relativistic, field-theoretical equations of state, a large fraction of their interior may exist in a D-3(2)-paired supefluid phase. The implications of such a D-3(2) superfluid in massive neutron stars is discussed with respect to observable pulsar phenomena. Another interesting phenomenon, discussed in the paper, concerns the numerical finding of two critical superfluid temperatures for a given density in the case of isospin-asymmetric matter. Using the BCS cut-off ansatz, a mathematical expression for the critical temperature is derived which confirms this finding analytically. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV MUNICH,INST THEORET PHYS,D-80333 MUNICH,GERMANY. RP Alm, T (reprint author), UNIV ROSTOCK,AG THEORET VIELTEILCHENPHYS,MAX PLANCK GESELL,D-18051 ROSTOCK,GERMANY. NR 24 TC 32 Z9 32 U1 0 U2 1 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 JUL 22 PY 1996 VL 604 IS 4 BP 491 EP 504 DI 10.1016/0375-9474(96)00153-4 PG 14 WC Physics, Nuclear SC Physics GA UY534 UT WOS:A1996UY53400008 ER PT J AU ArkaniHamed, N Cheng, HC Hall, LJ AF ArkaniHamed, N Cheng, HC Hall, LJ TI A new supersymmetric framework for fermion masses SO NUCLEAR PHYSICS B LA English DT Article DE flavor symmetries; fermion masses; radiative electron mass; flavor mixings; R parity ID MATRIX MODELS; SUPERGRAVITY AB Supersymmetric theories involving a spontaneously broken flavor symmetry can solve the flavor-changing problem while having quark and lepton masses derived from both F and D terms. As an example, a theory of leptons is constructed in which holomorphy constrains the electron to be massless at tree level. The electron flavor symmetries are broken by D terms, leading to flavor mixing in the slepton mass matrices, which allows a radiative electron mass to be generated by the gauge interactions of supersymmetric QED. Such a radiative origin for the electron mass can be probed by searches for tau --> e gamma, and could be verified or eliminated by measurements of slepton pair production. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP ArkaniHamed, N (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. NR 15 TC 20 Z9 20 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JUL 22 PY 1996 VL 472 IS 1-2 BP 95 EP 108 DI 10.1016/0550-3213(96)00226-X PG 14 WC Physics, Particles & Fields SC Physics GA UX863 UT WOS:A1996UX86300005 ER PT J AU Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alitti, J Alvarez, G Alves, GA Amidi, E Amos, N Anderson, EW Aronson, SH Astur, R Avery, RE Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Bendich, J Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Bischoff, A Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C Cullenvidal, D Cummings, MAC Cutts, D Dahl, OI De, K Demarteau, M Denisenko, N Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Dixon, R Draper, P Drinkard, J Ducros, Y Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahey, S Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Franzini, P Fuess, S Gallas, E Galyaev, AN Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glebov, V Glenn, S Glicenstein, JF Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Graf, N Grannis, PD Green, DR Green, J Greenlee, H Griffin, G Grossman, N Grudberg, P Grunendahl, S Gu, WX Guglielmo, G Guida, JA Guida, JM Guryn, W Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hatcher, R Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Hu, T Huehn, T Igarashi, S Ito, AS James, E Jaques, J Jerger, SA Jiang, JZY JoffeMinor, T Johari, H Johns, K Johnson, M Johnstad, H Jonckheere, A Jones, M Jotlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kerth, L Kim, CL Kim, SK Klatchko, A Klima, B Klochkov, BI Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kourlas, J Kozelov, AC Kozlovski, EA Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Landsberg, G Lebrat, JF Leflat, A Li, H Li, J Li, YK LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Mani, S Mao, HS Margulies, S Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McKibben, T McKinley, J McMahon, T Melanson, HL Neto, JRTD Merritt, KW Miettinen, H Mincer, A DeMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P DaMotta, H Mudan, M Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Neis, E Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, CH Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peryshkin, A Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rao, MVS Rapidis, PA Rasmussen, L Read, AL Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, JB Sirotenko, V Smart, W Smith, A SMith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Taylor, TL Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Virador, PRG Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H Wen, F White, A White, JT Wightman, JA Wilcox, J Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alitti, J Alvarez, G Alves, GA Amidi, E Amos, N Anderson, EW Aronson, SH Astur, R Avery, RE Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Bendich, J Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Bischoff, A Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C Cullenvidal, D Cummings, MAC Cutts, D Dahl, OI De, K Demarteau, M Denisenko, N Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Dixon, R Draper, P Drinkard, J Ducros, Y Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahey, S Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Franzini, P Fuess, S Gallas, E Galyaev, AN Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glebov, V Glenn, S Glicenstein, JF Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Graf, N Grannis, PD Green, DR Green, J Greenlee, H Griffin, G Grossman, N Grudberg, P Grunendahl, S Gu, WX Guglielmo, G Guida, JA Guida, JM Guryn, W Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hatcher, R Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Hu, T Huehn, T Igarashi, S Ito, AS James, E Jaques, J Jerger, SA Jiang, JZY JoffeMinor, T Johari, H Johns, K Johnson, M Johnstad, H Jonckheere, A Jones, M Jotlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kerth, L Kim, CL Kim, SK Klatchko, A Klima, B Klochkov, BI Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kourlas, J Kozelov, AC Kozlovski, EA Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Landsberg, G Lebrat, JF Leflat, A Li, H Li, J Li, YK LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Mani, S Mao, HS Margulies, S Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McKibben, T McKinley, J McMahon, T Melanson, HL Neto, JRTD Merritt, KW Miettinen, H Mincer, A DeMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P DaMotta, H Mudan, M Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Neis, E Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, CH Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peryshkin, A Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rao, MVS Rapidis, PA Rasmussen, L Read, AL Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, JB Sirotenko, V Smart, W Smith, A SMith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Taylor, TL Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Virador, PRG Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H Wen, F White, A White, JT Wightman, JA Wilcox, J Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A TI Azimuthal decorrelation of jets widely separated in rapidity SO PHYSICAL REVIEW LETTERS LA English DT Article ID DIFFERENTIAL CROSS-SECTION; HADRON-COLLISIONS; DIJET PRODUCTION; DISTRIBUTIONS; SINGULARITY; GLUONS; QCD AB This study reports the first measurement of the azimuthal decorrelation between jets with pseudorapidity separation up to five units. The data were accumulated using the D0 detector during the 1992-1993 collider run of the Fermilab Tevatron at root s = 1.8 TeV. These results are compared to next-to-leading order (NLO) QCD predictions and to two leading-log approximations (LLA) where the leading-log terms are re-summed to all orders in alpha(S). The final state jets as predicted by NLO QCD show less azimuthal decorrelation than the data. The parton showering LLA Monte Carlo HERWIG describes the data well; an analytical LLA prediction based on Balitsky-Fadin-Kuraev-Lipatov resummation shows more decorrelation than the data. C1 UNIV LOS ANDES,BOGOTA,COLOMBIA. UNIV ARIZONA,TUCSON,AZ 85721. BOSTON UNIV,BOSTON,MA 02215. BROOKHAVEN NATL LAB,UPTON,NY 11973. BROWN UNIV,PROVIDENCE,RI 02912. UNIV BUENOS AIRES,BUENOS AIRES,DF,ARGENTINA. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV CALIF IRVINE,IRVINE,CA 92717. UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. CTR BRASILEIRO PESQUISAS FIS,LAFEX,RIO JANEIRO,BRAZIL. CTR INVEST & ESTUDIOS AVANZADOS,MEXICO CITY,DF,MEXICO. COLUMBIA UNIV,NEW YORK,NY 10027. UNIV DELHI,DELHI 110007,INDIA. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. UNIV HAWAII,HONOLULU,HI 96822. UNIV ILLINOIS,CHICAGO,IL 60607. INDIANA UNIV,BLOOMINGTON,IN 47405. IOWA STATE UNIV,AMES,IA 50011. KOREA UNIV,SEOUL 136701,SOUTH KOREA. KYUNGSUNG UNIV,PUSAN,SOUTH KOREA. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,BERKELEY,CA 94720. UNIV MARYLAND,COLLEGE PK,MD 20742. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. MOSCOW MV LOMONOSOV STATE UNIV,MOSCOW,RUSSIA. UNIV NEBRASKA,LINCOLN,NE 68588. NYU,NEW YORK,NY 10003. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV OKLAHOMA,NORMAN,OK 73019. PANJAB UNIV,CHANDIGARH 160014,INDIA. INST HIGH ENERGY PHYS,PROTVINO 142284,RUSSIA. PURDUE UNIV,W LAFAYETTE,IN 47907. RICE UNIV,HOUSTON,TX 77251. UNIV ESTADUAL RIO DE JANEIRO,RIO JANEIRO,BRAZIL. UNIV ROCHESTER,ROCHESTER,NY 14627. SEOUL NATL UNIV,SEOUL,SOUTH KOREA. SUNY STONY BROOK,STONY BROOK,NY 11794. TATA INST FUNDAMENTAL RES,BOMBAY 400005,MAHARASHTRA,INDIA. UNIV TEXAS,ARLINGTON,TX 76019. TEXAS A&M UNIV,COLLEGE STN,TX 77843. CENS,CEA,SERV PHYS PARTICULES,DEPT ASTROPHYS PHYS PARTICULES PHYS NUCL & INSTRU,GIF SUR YVETTE,FRANCE. NORTHEASTERN UNIV,BOSTON,MA 02115. RP Abachi, S (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. RI Sznajder, Andre/L-1621-2016; Aihara, Hiroaki/F-3854-2010; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Leflat, Alexander/D-7284-2012; Klyukhin, Vyacheslav/D-6850-2012; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013; Kim, Sun Kee/G-2042-2015; Chekulaev, Sergey/O-1145-2015; de Mello Neto, Joao/C-5822-2013; OI Sznajder, Andre/0000-0001-6998-1108; Aihara, Hiroaki/0000-0002-1907-5964; Klyukhin, Vyacheslav/0000-0002-8577-6531; De, Kaushik/0000-0002-5647-4489; Kim, Sun Kee/0000-0002-0013-0775; de Mello Neto, Joao/0000-0002-3234-6634; Baarmand, Marc/0000-0002-9792-8619 NR 31 TC 34 Z9 34 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 JUL 22 PY 1996 VL 77 IS 4 BP 595 EP 600 DI 10.1103/PhysRevLett.77.595 PG 6 WC Physics, Multidisciplinary SC Physics GA UY984 UT WOS:A1996UY98400003 ER PT J AU Ormand, WE Bortignon, PF Broglia, RA AF Ormand, WE Bortignon, PF Broglia, RA TI Temperature dependence of the width of the giant dipole resonance in Sn-120 and Pb-208 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HOT ROTATING NUCLEI; THERMAL FLUCTUATIONS; FINITE TEMPERATURE AB The giant-dipole resonance (GDR) in Sn-120 and Pb-208 is studied as a function of excitation energy, angular momentum, and intrinsic width. Theoretical evaluations of the full width at half maximum (FWHM) for the GDR strength function, are compared with recent experimental data and are found to be in overall agreement. Differences observed between Sn-120 and Pb-208,, attributed to strong shell corrections in Pb-208 favoring spherical shapes at low temperatures. At high temperature, the FWHM in Sn-120 exhibits effects due to the evaporation width of the compound nucleus. C1 OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. UNIV COPENHAGEN,NIELS BOHR INST,DK-2100 COPENHAGEN O,DENMARK. RP Ormand, WE (reprint author), UNIV TENNESSEE,DEPT PHYS,401 NIELSEN HALL,KNOXVILLE,TN 37996, USA. NR 28 TC 73 Z9 74 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 22 PY 1996 VL 77 IS 4 BP 607 EP 610 DI 10.1103/PhysRevLett.77.607 PG 4 WC Physics, Multidisciplinary SC Physics GA UY984 UT WOS:A1996UY98400006 ER PT J AU Billinge, SJL DiFrancesco, RG Kwei, GH Neumeier, JJ Thompson, JD AF Billinge, SJL DiFrancesco, RG Kwei, GH Neumeier, JJ Thompson, JD TI Direct observation of lattice polaron formation in the local structure of La1-xCaxMnO3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNETORESISTANCE; FILMS AB The local atomic structure of La1-xCaxMnO3 (x = 0.12, 0.21, and 0.25) has been studied using pair-distribution-function analysis of neutron powder-diffraction data. A change is seen in the local structure which can be correlated with the metal-insulator transition in the x = 0.21 and 0.25 samples. This local structural change is modeled as an isotropic collapse of oxygen towards Mn of magnitude delta = 0.12 Angstrom occurring on one in four Mn sites. We argue that this is the direct observation of lattice polaron formation, associated with the metal-insulator transition in these materials. C1 MICHIGAN STATE UNIV,CTR FUNDAMENTAL MAT RES,E LANSING,MI 48824. LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Billinge, SJL (reprint author), MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824, USA. NR 29 TC 372 Z9 373 U1 4 U2 26 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 JUL 22 PY 1996 VL 77 IS 4 BP 715 EP 718 DI 10.1103/PhysRevLett.77.715 PG 4 WC Physics, Multidisciplinary SC Physics GA UY984 UT WOS:A1996UY98400033 ER PT J AU Watson, GM Gibbs, D Lander, GH Gaulin, BD Berman, LE Matzke, H Ellis, W AF Watson, GM Gibbs, D Lander, GH Gaulin, BD Berman, LE Matzke, H Ellis, W TI X-ray scattering study of the magnetic structure near the (001) surface of UO2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID 1ST-ORDER BULK TRANSITIONS; DIFFRACTION AB We report glancing-incidence x-ray scattering studies of the magnetic structure observed near the (001) surface of the antiferromagnet UO2. Within about 50 Angstrom of the surface, the magnetic scattering intensity decreases continuously as the hulk Neel temperature is approached from below. This contrasts with the bulk transition, which is discontinuous. C1 COMMISS EUROPEAN COMMUNITIES, JOINT RES CTR, INST TRANSURANIUM ELEMENTS, D-76125 KARLSRUHE, GERMANY. MCMASTER UNIV, DEPT PHYS & ASTRON, HAMILTON, ON L8S 4M1, CANADA. BROOKHAVEN NATL LAB, NATL SYNCHROTRON LIGHT SOURCE, UPTON, NY 11973 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. RI Piper, Walter/B-7908-2009 NR 29 TC 39 Z9 39 U1 0 U2 4 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 JUL 22 PY 1996 VL 77 IS 4 BP 751 EP 754 DI 10.1103/PhysRevLett.77.751 PG 4 WC Physics, Multidisciplinary SC Physics GA UY984 UT WOS:A1996UY98400042 ER PT J AU Cook, JS AF Cook, JS TI Publish or perish SO SCIENTIST LA English DT Letter RP Cook, JS (reprint author), OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37831, USA. NR 2 TC 0 Z9 0 U1 1 U2 1 PU SCIENTIST INC PI PHILADELPHIA PA 3600 MARKET ST SUITE 450, PHILADELPHIA, PA 19104 SN 0890-3670 J9 SCIENTIST JI Scientist PD JUL 22 PY 1996 VL 10 IS 15 BP 11 EP 11 PG 1 WC Information Science & Library Science; Multidisciplinary Sciences SC Information Science & Library Science; Science & Technology - Other Topics GA UY899 UT WOS:A1996UY89900009 ER PT J AU Gill, AJ Kibble, TWB AF Gill, AJ Kibble, TWB TI Quench-induced vortices in the symmetry-broken phase of liquid He-4 SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID COSMIC STRINGS; SUPERFLUID-HELIUM; TRANSITIONS; DYNAMICS AB Motivated by the study of cosmological phase transitions, our understanding of the formation of topological defects during spontaneous symmetry breaking and the associated nonequilibrium field theory has recently changed. Experiments have been performed in superfluid He-4 to test the new ideas involved. in particular, it has been observed that a vortex density is seen immediately after pressure quenches from just below the lambda transition. We discuss possible interpretations of these vortices, conclude they are consistent with our ideas of vortex formation and propose a modification of the original experiments. C1 ISAAC NEWTON INST MATH SCI,CAMBRIDGE CB3 0EH,ENGLAND. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. HELSINKI UNIV TECHNOL,LOW TEMP LAB,SF-02150 ESPOO,FINLAND. RP Gill, AJ (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,S KENSINGTON,LONDON SW7 2BZ,ENGLAND. NR 25 TC 10 Z9 10 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD JUL 21 PY 1996 VL 29 IS 14 BP 4289 EP 4305 DI 10.1088/0305-4470/29/14/044 PG 17 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA VA532 UT WOS:A1996VA53200044 ER PT J AU Brown, PL Drummond, SE Palmer, DA AF Brown, PL Drummond, SE Palmer, DA TI Hydrolysis of magnesium(II) at elevated temperatures SO JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS LA English DT Article ID METAL-IONS; AQUEOUS-SOLUTIONS; CHLORIDE MEDIA; NACL MEDIA; 600-DEGREES-C; IONIZATION; CONSTANTS; PRESSURES; MOLAL AB A potentiometric titration technique utilising a a hydrogen-electrode concentration cell was applied to study the hydrolytic behaviour of the magnesium(II) ion in 0.10 and 1.0 mol kg(-1) sodium chloride at 60, 100, 150 and 200 degrees C. Data analysis indicates the presence of Mg2+ (aq) and the solid species Mg(OH)(2), (s), only. Independent measurements have confirmed that [Mg(OH)](+) (aq) is a negligible ionic species under the prevailing experimental conditions. Experimental evidence indicated that the solid species formed both rapidly and reversibly. The equilibrium quotients for brucite formation were determined for each temperature and ionic strength investigated and the corresponding enthalpy and entropy of formation calculated. Formation constants have also been calculated at zero ionic strength using the Debye-Huckel equation, and these data, together with some other literature data, comply with the equation log beta(12s)degrees = 2.49-(5847/T) where log beta(12s)degrees is the logarithm of the formation constant of brucite at zero ionic strength and T is the temperature in Kelvin. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Brown, PL (reprint author), AUSTRALIAN NUCL SCI & TECHNOL ORG,ENVIRONM DIV,PRIVATE MAIL BAG 1,MENAI,NSW 2234,AUSTRALIA. NR 24 TC 18 Z9 18 U1 1 U2 4 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0300-9246 J9 J CHEM SOC DALTON JI J. Chem. Soc.-Dalton Trans. PD JUL 21 PY 1996 IS 14 BP 3071 EP 3075 DI 10.1039/dt9960003071 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA UZ317 UT WOS:A1996UZ31700026 ER PT J AU Mezyk, SP Tateishi, M MacFarlane, R Bartels, DM AF Mezyk, SP Tateishi, M MacFarlane, R Bartels, DM TI pK(a) of the hydrazinium ion and the reaction of hydrogen atoms with hydrazine in aqueous solution SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID EPR MEASUREMENT; ARRHENIUS PARAMETERS; PULSE-RADIOLYSIS; WATER RADIOLYSIS; RATE-CONSTANT AB The techniques of electron pulse radiolysis and paramagnetic resonance free induction decay (FID) attenuation measurements have been used to determine Arrhenius parameters for the reaction of the hydrogen atom with N2H5+ and N2H4 in aqueous solution. At 41.6 degrees C, a scavenging rate constant of (5.8 +/- 1.9) x 10(6) dm(3) mol(-1) s(-1) was directly measured for the N2H5+ reaction, with a corresponding activation energy of 61.4 +/- 1.2 kJ mol(-1) over the temperature range 41.6-82.1 degrees C. The pK(a) of the hydrazinium ion was determined by absorption spectroscopy, and over the temperature range 0-80 degrees C, this equilibrium was well described by pK(a) = (2600 +/- 30)/T - (0.771 +/- 0.099). Using these values, and FID attenuation measurements in borax buffered solution over the temperature range 0.2-83.0 degrees C, the hydrogen atom rate constant for N2H4 reaction was calculated to be (6.74 +/- 0.23) x 10(7) dm(3) mol(-1) s(-1) (24.5 degrees C), with an activation energy of 16.28 +/- 0.80 kJ mol(-1). The reaction rate of H-. with N2H4 is consistent with a hydrogen atom abstraction, giving H-2 and (N2H3)-N-. radical as products, as in the gas phase. Based on the large activation enthalpy and entropy obtained for the reaction of hydrogen atoms with N2H5+, however, we suggest that this is more likely an addition-fragmentation process, to give (NH2)-N-., NH3 and (H+)(aq) as products. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP Mezyk, SP (reprint author), ATOM ENERGY CANADA LTD,WHITESHELL LABS,PINAWA,MB R0E 1L0,CANADA. NR 34 TC 12 Z9 12 U1 0 U2 7 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD JUL 21 PY 1996 VL 92 IS 14 BP 2541 EP 2545 DI 10.1039/ft9969202541 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UZ148 UT WOS:A1996UZ14800006 ER PT J AU Mehr, R Perelson, AS FridkisHareli, M Globerson, A AF Mehr, R Perelson, AS FridkisHareli, M Globerson, A TI Feedback regulation of T cell development in the thymus SO JOURNAL OF THEORETICAL BIOLOGY LA English DT Article ID BONE-MARROW CELLS; RECEPTOR TRANSGENIC MICE; THYMOCYTE DEVELOPMENT; IMMATURE THYMOCYTES; POSITIVE SELECTION; DIFFERENTIATION; COLONIZATION; KINETICS; LYMPHOCYTES; SUBSET AB Recent findings suggest that mature T cells in the thymus may regulate the growth and differentiation of immature thymocytes. Here we use mathematical modeling and computer simulations to identify the thymocyte subsets that might serve as targets for regulation, and the processes that might be affected by regulation. Our results suggest that thymocyte development is subject to regulation through two feedback loops: mature CD4(+) T cells exert a positive feedback on the single positive CD4(+)8(-) thymocyte compartment, by reducing CD4(+)8(-) cell death and possibly accelerating the differentiation of CD4(+)8(+) thymocytes into CD4(+)8(-) thymocytes; they may also exert a negative feedback on the double-positive CD4(+)8(+) thymocyte compartment, by reducing the proliferation or accelerating the maturation of these cells. (C) 1996 Academic Press Limited C1 WEIZMANN INST SCI,DEPT CELL BIOL,IL-76100 REHOVOT,ISRAEL. RP Mehr, R (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. OI Mehr, Ramit/0000-0002-4303-6834 FU NIAID NIH HHS [AI28433] NR 50 TC 29 Z9 30 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-5193 J9 J THEOR BIOL JI J. Theor. Biol. PD JUL 21 PY 1996 VL 181 IS 2 BP 157 EP 167 DI 10.1006/jtbi.1996.0122 PG 11 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA VE405 UT WOS:A1996VE40500005 PM 8935593 ER PT J AU Imel, GR Singleterry, RC Gillespie, GH McMichael, GE AF Imel, GR Singleterry, RC Gillespie, GH McMichael, GE TI Moderator design for accelerator driven neutron radiography sources SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 2nd International Topical Meeting on Neutron Radiography System Design and Characterization CY NOV 12-18, 1995 CL RIKKYO UNIV, INST ATOM ENERGY, NAGASAKA, JAPAN SP Inoue Fdn Sci, Atom Energy Soc Japan, Japanese Soc Non Destruct Inspect, Radiat Applicat Dev Assoc, Japan Atom Energy Res Inst, Tokai Estab, Rikkyo Univ, Inst Atom Energy HO RIKKYO UNIV, INST ATOM ENERGY AB This paper demonstrates the design of a moderator system that is capable obtaining image plane fluxes on the order of 10(6) n cm(-2) s(-1) from continuous wave linacs with currents of ten mA or less of protons in the range 2.5 to 4 MeV. A Monte Carlo code has been used to analyze target/moderator configurations that could be used with an accelerator such as Argonne's Continuous Wave Linac (ACWL). These analyses have shown the feasibility of using ACWL or other high current linacs to generate neutron beams with high intensity. C1 G H GILLESPIE ASSOCIATES INC,DEL MAR,CA 92014. ARGONNE NATL LAB,ARGONNE,IL 60439. RP Imel, GR (reprint author), ARGONNE NATL LAB,POB 2528,IDAHO FALLS,ID 83403, USA. NR 8 TC 5 Z9 7 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 JUL 21 PY 1996 VL 377 IS 1 BP 20 EP 22 DI 10.1016/0168-9002(96)00108-8 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA UY527 UT WOS:A1996UY52700005 ER PT J AU Cremers, DA Jeffries, J Miziolek, AW AF Cremers, DA Jeffries, J Miziolek, AW TI Feature issue on applied spectroscopy for sensors and chemical analysis: Introduction SO APPLIED OPTICS LA English DT Editorial Material C1 USA,RES LAB,ABERDEEN PROVING GROUND,MD 21005. RP Cremers, DA (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,GRP CST1,MS J565,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUL 20 PY 1996 VL 35 IS 21 BP 3991 EP 3991 DI 10.1364/AO.35.003991 PG 1 WC Optics SC Optics GA VA608 UT WOS:A1996VA60800001 PM 21102800 ER PT J AU Priedhorsky, WC AF Priedhorsky, WC TI Contrast and signal-to-noise ratio in long-distance starlight imaging SO APPLIED OPTICS LA English DT Article; Proceedings Paper CT OSA 1995 Annual Meeting CY 1995 CL PORTLAND, OR SP Opt Soc Amer DE photon counting; remote sensing; night vision; starlight imaging; microchannel plates ID ULTRAVIOLET AB A small telescope on an airplane or in low Earth orbit can, in principle, resolve ground objects under starlight with useful resolution. For an similar to 50-cm aperture and similar to 100-s exposure, one can obtain a resolution of tens of centimeters from an aircraft and a few meters from orbit. Such starlight images are photon poor, and feature detection depends on photon statistics. Scattered light, atmospheric absorption, and foreground airglow all degrade image contrast. I report an investigation into image signal-to-noise ratio using first-order analytical approximations. We find that, for a given angular resolution, the signal-to-noise ratio for spaceborne images is degraded approximately a factor of 1.7, compared with airborne images, by foreground airglow. Image signal-to-noise ratio improves as the passband moves to the red and as skies become brighter from artificial illumination. (C) 1996 Optical Society of America RP Priedhorsky, WC (reprint author), LOS ALAMOS NATL LAB, MAIL STOP D436, LOS ALAMOS, NM 87545 USA. OI Priedhorsky, William/0000-0003-0295-9138 NR 18 TC 1 Z9 1 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUL 20 PY 1996 VL 35 IS 21 BP 4173 EP 4179 DI 10.1364/AO.35.004173 PG 7 WC Optics SC Optics GA VA608 UT WOS:A1996VA60800028 PM 21102827 ER PT J AU Kankelborg, CC Walker, ABC Hoover, RB Barbee, TW AF Kankelborg, CC Walker, ABC Hoover, RB Barbee, TW TI Observation and modeling of soft X-ray bright points .1. Initial results SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun, corona; Sun, magnetic fields; Sun, transition region; Sun, X-rays, gamma rays ID SOLAR TELESCOPE ARRAY; TRANSITION REGION; CORONAL LOOPS; ENERGY-BALANCE; QUIET-SUN; YOHKOH AB The Multi-Spectral Solar Telescope Array was launched from White Sands Missile Range, New Mexico, on 1991 May 13 at 1905 UT. Full-disk, high-resoluton solar images were obtained in a variety of soft X-ray and far-ultraviolet wavelengths. The 193 Angstrom (Fe XII) and 44 Angstrom (Si XII) images show a large number of coronal bright points. The high spatial resolution of the Fe XII image allows many of the bright points to be resolved as tiny loops. Co-alignment of the soft X-ray images with the 1216 Angstrom Ly alpha image reveals that all the coronal bright points have counterparts in the transition region, often resolved as a pair of footpoints, which are brighter than neighboring elements of the chromospheric network. Moreover, comparison with the KPNO magnetogram shows dipole structures coincident with nearly all of the bright points. We present a quantitative analysis based on preliminary photometry of four of the bright points that were observed. By fitting a simple, numerical loop model to the photometric data, we estimate the magnitude of the coronal heating in these structures. The rate of heating per unit footpoint area is found to be similar to previous measurements for much larger coronal structures. Implications for heating of the chromosphere and lower transition region are also discussed. C1 NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, HUNTSVILLE, AL 35812 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP STANFORD UNIV, DEPT PHYS & APPL PHYS, STANFORD, CA 94305 USA. NR 30 TC 26 Z9 26 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1996 VL 466 IS 1 BP 529 EP + DI 10.1086/177529 PN 1 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UW721 UT WOS:A1996UW72100042 ER PT J AU Hu, MZC Norman, JM Faison, BD Reeves, ME AF Hu, MZC Norman, JM Faison, BD Reeves, ME TI Biosorption of uranium by Pseudomonas aeruginosa strain CSU: Characterization and comparison studies SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE biosorption; sorption; uranium; iron; Pseudomonas aeruginosa; bacteria; remediation ID RHIZOPUS-ARRHIZUS BIOMASS; PENICILLIUM BIOMASS; FUNGAL BIOMASS; METAL ADSORPTION; RECOVERY; ACCUMULATION; REMOVAL; VI; MICROORGANISMS; BIOTECHNOLOGY AB Pseudomonas aeruginosa strain CSU, a nongenetically engineered bacterial strain known to bind dissolved hexavalent uranium (as UO22+ and/or its cationic hydroxo complexes), was characterized with respect to its sorptive activity (equilibrium and dynamics). Living, heat-killed, permeabilized, and unreconstituted lyophilized cells were all capable of binding uranium. The uranium biosorption equilibrium could be described by the Langmuir isotherm. The rate of uranium adsorption increased following permeabilization of the outer and/or cytoplasmic membrane by organic solvents such as acetone. P. aeruginosa CSU biomass was significantly more sorptive toward uranium than certain novel, patented biosorbents derived from algal or fungal biomass sources. P. aeruginosa CSU biomass was also competitive with commercial cation-exchange resins, particularly in the presence of dissolved transition metals. Uranium binding by P. aeruginosa CSU was clearly pH dependent. Uranium loading capacity increased with increasing pH under acidic conditions, presumably as a function of uranium speciation and due to the H+ competition at some binding sites. Nevertheless, preliminary evidence suggests that this microorganism is also capable of binding anionic hexavalent uranium complexes. Ferric iron was a strong inhibitor of uranium binding to P. aeruginosa CSU biomass, and the presence of uranium also decreased the Fe3+ loading when the biomass was not saturated with Fe3+, suggesting that Fe3+ and uranium may share the same binding sites on biomass. Although the equilibrium loading capacity of uranium was greater than that of Fe3+, this biomass showed preference of binding Fe3+ over uranium. Thus, a two-stage process in which iron and uranium are removed in consecutive steps was proposed for efficient use of the biomass as a biosorbent in uranium removal from mine wastewater, especially acidic leachates. (C) 1996 John Wiley & Sons, Inc. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. OI Hu, Michael/0000-0001-8461-9684 NR 35 TC 101 Z9 108 U1 4 U2 24 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD JUL 20 PY 1996 VL 51 IS 2 BP 237 EP 247 DI 10.1002/(SICI)1097-0290(19960720)51:2<237::AID-BIT14>3.0.CO;2-J PG 11 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA UR420 UT WOS:A1996UR42000014 PM 18624334 ER PT J AU Margulies, L Dennis, KW Kramer, MJ McCallum, RW AF Margulies, L Dennis, KW Kramer, MJ McCallum, RW TI Effect of P(O-2) and Ag content on the decomposition pathway of Bi2Sr2CaCu2Ox SO PHYSICA C LA English DT Article DE Bi2212; P(O-2); Ag; phase relations ID CA-CU-O; PHASE-EQUILIBRIA; CRYSTALLINE PHASES; SYSTEM; BI2SR2CA1CU2O8+X; TEMPERATURE; PRESSURES; CHEMISTRY; PORTIONS AB The decomposition pathway of Bi2Sr2CaCu2Ox (Bi2212) with 0, 2 and 10 wt.% Ag added has been examined at 0.01, 0.21, and 1 bar P(O-2) by performing scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS) and microprobe analysis on oil quenched samples. A series of pseudo-ternary phase diagrams at each P(O-2) was constructed to describe the evolution of the phase assemblage with temperature. Ag showed limited solubility (2-3 wt.%) in the ceramic melt which depressed the reaction temperature of each step along the decomposition pathway. The first solid phases to form upon the peritectic decomposition of Bi2212 were Bi9Sr11Ca5Ox (9115) and (Sr1-xCax)(14)Cu24O41 (14,24) in 1 bar O-2, (9115) and (Sr1-xCax)CuO2 (11) in 0.21 bar O-2, and (11), (Sr1-xCax)(2)CuO3 (21) and Bi-2(Sr1-xCax)(3)O-x (23x) in 0.01 bar O-2. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NR 30 TC 24 Z9 26 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUL 20 PY 1996 VL 266 IS 1-2 BP 62 EP 74 DI 10.1016/0921-4534(96)00289-4 PG 13 WC Physics, Applied SC Physics GA UZ835 UT WOS:A1996UZ83500008 ER PT J AU Fritz, JS Freeze, RC Thornton, MJ Gjerde, DT AF Fritz, JS Freeze, RC Thornton, MJ Gjerde, DT TI Methods for concentrating metal ions prior to analysis by ion chromatography or capillary electrophoresis SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 8th International Ion Chromatography Symposium CY OCT 01-05, 1995 CL DALLAS, TX DE sample preparation; metal ions ID FUNCTIONAL-GROUP STRUCTURE; ANION-EXCHANGERS; SELECTIVITY; CAPACITY AB In ion chromatography and particularly in capillary electrophoresis, it is often necessary to preconcentrate metal ions to be determined and to remove larger amounts of matrix ions such as Na+, Mg2+, and Ca2+. Several general techniques for concentration of selected metal ions are reviewed and illustrated by specific examples. These techniques include the use of chelating resins and the formation of soluble complexes in solution with subsequent retention by ordinary solid-phase extraction (SPE) columns. Many of the chelating resins used in the past for preconcentration of metal cations have been relatively inefficient. More effective resins can be created by careful attention to the particle size and physical structure of the resin, its chelating capacity, and the selectivity and kinetics of the chelating groups present in the resin. Likewise, carefully designed soluble complexing reagents can be used effectively in conjunction with modem SPE techniques. These principles are illustrated by new types of chelating resins and reagents that we have prepared and tested. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. SARASEP INC,SANTA CLARA,CA 95054. RP Fritz, JS (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011, USA. NR 11 TC 17 Z9 17 U1 1 U2 1 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 JUL 19 PY 1996 VL 739 IS 1-2 BP 57 EP 61 DI 10.1016/0021-9673(96)00041-6 PG 5 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA UZ355 UT WOS:A1996UZ35500008 ER PT J AU Tanaka, K Ohta, K Fritz, JS AF Tanaka, K Ohta, K Fritz, JS TI Ion-exclusion chromatography of ethanolamines on an anion-exchange resin by elution with polyols and sugars SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 8th International Ion Chromatography Symposium CY OCT 01-05, 1995 CL DALLAS, TX DE mobile phase composition; stationary phases, LC; ethanolamines; polyols; sugars ID ALIPHATIC CARBOXYLIC-ACIDS; CONDUCTIVITY DETECTION; SEPARATION; COLUMN AB Ion-exclusion chromatography of mono-, di- and triethanolamines of different basicity (pK(b)) and hydrophobicity was investigated on a polystyrene-divinylbenzene (PS-DVB)-based strongly basic anion-exchange resin in the OH- form. Conductivity detection and UV detection at 200 nm were used. When water was as an eluent, the ethanoamines were separated from strong base (NaOH) but the resolution was low and some peaks were fronted. This is due mainly to adsorption as a side-effect in the ion-exclusion chromatography. To improve the peak shape and the peak resolution, aqueous eluents containing polyols or sugars with 1-8 alcoholic OH groups (methanol, ethylene glycol, glycerol, erythritol, xylitol, fructose, sorbitol and sucrose) were tested for the ion-exclusion chromatographic separation of ethanolamines. When aqueous eluents containing polygols or sugars were used, peak fronting was decreased drastically by increasing a number of OH groups in the polyols and sugars. This is due mainly to the increase in the hydrophilicity of the PS-DVB surface by the OH groups. When an aqueous fructose eluent was used, fructose was strongly adsorbed on the resin surface. By this permanent coating method, the ion-exclusion chromatographic separation of ethanolamines was accomplished successfully by elution with water with reasonable resolution and highly sensitive UV and conductimetric detection. C1 IOWA STATE UNIV,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. RP Tanaka, K (reprint author), NATL IND RES INST NAGOYA,KITA KU,1-1 HIRATE CHO,NAGOYA,AICHI 462,JAPAN. NR 13 TC 18 Z9 18 U1 1 U2 1 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 JUL 19 PY 1996 VL 739 IS 1-2 BP 317 EP 325 DI 10.1016/0021-9673(96)00050-7 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA UZ355 UT WOS:A1996UZ35500039 ER PT J AU Loeser, AG Shen, ZX Dessau, DS Marshall, DS Park, CH Fournier, P Kapitulnik, A AF Loeser, AG Shen, ZX Dessau, DS Marshall, DS Park, CH Fournier, P Kapitulnik, A TI Excitation gap in the normal state of underdoped Bi2Sr2CaCu2O8+delta SO SCIENCE LA English DT Article ID A-B PLANE; HIGH-TC; SPIN DYNAMICS; SUPERCONDUCTIVITY; RELAXATION; ANISOTROPY; CU AB Angle-resolved photoemission experiments reveal evidence of an energy gap in the normal state excitation spectrum of the cuprate superconductor Bi2Sr2CaCu2O8+delta. This gap exists only in underdoped samples and closes around the doping level at which the superconducting transition temperature T-c is a maximum. The momentum dependence and magnitude of the gap closely resemble those of the d(x2-y2) gap observed in the superconducting state. This observation is consistent with results from several other experimental techniques, which also indicate the presence of a gap in the normal stale. Some possible theoretical explanations for this effect are reviewed. C1 STANFORD UNIV, SOLID STATE LAB, STANFORD, CA 94305 USA. STANFORD UNIV, DEPT APPL PHYS, STANFORD, CA 94305 USA. RP STANFORD SYNCHROTRON RADIAT LAB, DEPT APPL PHYS, STANFORD, CA 94305 USA. NR 41 TC 797 Z9 804 U1 4 U2 49 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD JUL 19 PY 1996 VL 273 IS 5273 BP 325 EP 329 DI 10.1126/science.273.5273.325 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UY202 UT WOS:A1996UY20200029 ER PT J AU Lee, JW Tevault, CV Owens, TG Greenbaum, E AF Lee, JW Tevault, CV Owens, TG Greenbaum, E TI Oxygenic photoautotrophic growth without photosystem I SO SCIENCE LA English DT Article ID PHOTON REQUIREMENT; REACTION CENTERS; CHLAMYDOMONAS; EFFICIENCY AB Contrary to the prediction of the Z-scheme model of photosynthesis, experiments demonstrated that mutants of Chlamydomonas containing photosystem II (PSII) but lacking photosystem I (PSI) can grow photoautotrophically with O-2 evolution, using atmospheric CO2 as the sole carbon source. Autotrophic photosynthesis by PSI-deficient mutants was stable both under anaerobic conditions and in air (21 percent O-2) at an actinic intensity of 200 microeinsteins per square meter per second. This PSII photosynthesis, which was sufficient to support cell development and mobility, may also occur in wild-type green algae and higher plants. The mutants can survive under 2000 microeinsteins per square meter per second with air, although they have less resistance to photoinhibition. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. CORNELL UNIV,PLANT BIOL SECT,ITHACA,NY 14853. NR 21 TC 25 Z9 27 U1 1 U2 10 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUL 19 PY 1996 VL 273 IS 5273 BP 364 EP 367 DI 10.1126/science.273.5273.364 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UY202 UT WOS:A1996UY20200042 ER PT J AU Blum, O Lear, KL Hou, HQ Warren, ME AF Blum, O Lear, KL Hou, HQ Warren, ME TI Buried refractive microlenses formed by selective oxidation of AlGaAs SO ELECTRONICS LETTERS LA English DT Article DE aluminium gallium arsenide; oxidation ID LASERS AB The authors demonstrate a novel method of fabricating buried refractive microlenses formed by selective oxidation AlGaAs epitaxial layers on a GaAs substrate. By appropriate tailoring of the Al mole fraction in the vertical direction, a lens-shaped oxidation shape was achieved. Performance of the microlenses formed in this way was experimentally evaluated at 980 nm, and modelled theoretically. RP Blum, O (reprint author), SANDIA NATL LABS,DEPT 1312,MS0603,ALBUQUERQUE,NM, USA. NR 3 TC 9 Z9 9 U1 0 U2 1 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JUL 18 PY 1996 VL 32 IS 15 BP 1406 EP 1408 DI 10.1049/el:19960887 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA VA513 UT WOS:A1996VA51300056 ER PT J AU Shul, RJ McClellan, GB Pearton, SJ Abernathy, CR Constantine, C Barratt, C AF Shul, RJ McClellan, GB Pearton, SJ Abernathy, CR Constantine, C Barratt, C TI Comparison of dry etch techniques for GaN SO ELECTRONICS LETTERS LA English DT Article DE gallium nitride; etching ID HETEROSTRUCTURE AB Dry etching of GaN in Cl-2/H-2/CH4/Ar has been compared using electron cyclotron resonance (ECR), inductively coupled plasma (ICP), and reactive ion etch (RIE) systems. GaN etch rates and surface morphology were obtained as a function of RF power, and showed significant improvements under high density plasma conditions. C1 UNIV FLORIDA,GAINESVILLE,FL 32611. PLASMA THERM INC,ST PETERSBURG,FL 33716. RP Shul, RJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 5 TC 49 Z9 52 U1 1 U2 25 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JUL 18 PY 1996 VL 32 IS 15 BP 1408 EP 1409 DI 10.1049/el:19960943 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA VA513 UT WOS:A1996VA51300057 ER PT J AU Tran, K Scott, GW Funk, DJ Moore, DS AF Tran, K Scott, GW Funk, DJ Moore, DS TI Resonantly enhanced, degenerate four-wave mixing measurement of the cubic molecular hyperpolarizability of squaraine dyes at 700 nm SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID NONLINEAR OPTICAL SUSCEPTIBILITY; MULTIPLE FLUORESCENCE EMISSION; DOPED POLYMER SYSTEMS; ORGANIC SOLAR-CELLS; XEROGRAPHIC PROPERTIES; PHOTOCHEMISTRY; CHEMISTRY; SQUARYLIUM; SOLVENT; STATES AB We report the results of resonantly enhanced, degenerate four-wave mixing (DFWM) measurements of the cubic molecular hyperpolarizability coefficient (gamma) of four squaraine dyes. Different determinations of gamma were performed at 696 and 710 nm with both ultrashort (210 fs) and somewhat longer (3 ps) duration laser pulses using the forward wave geometry. Bis[4-(dimethylamino)phenyl]squaraine (H-Sq), bis[4-(dimethy lamino)-2-hydroxyphenyl]squaraine (HO-Sq), bis(2,4,6-trihydroxyphenyl)squaraine (3HO-Sq), and diazulenylsquaraine (Az-Sq) were investigated as a function of concentration in liquid solutions and polymer blends, enabling the calculation of gamma from the measured values of the third-order nonlinear susceptibilities, chi((3)), of these samples. All values of gamma for these squaraines were found to be negative with large absolute magnitudes, up to similar to 8 x 10(-32) in esu, ''units'' [9.9 X 10(-57) C m(4) V-3 (SI units)] for the real part of gamma for Az-Sq at 696 nm. [We discuss the conversion of esu units to SI units for the quadratic (beta) and cubic hyperpolarizability coefficients (gamma) in the Appendix of this paper, reporting our results throughout in both systems of units.] Significant imaginary contributions to gamma were also observed for Az-Sq, but not for the other squaraines as expected from differences in absorption at these wavelengths. The DFWM signals exhibited the expected cubic intensity dependence, polarization dependence, and instantaneous time response, effectively ruling out any contributions to the measured values of gamma from experimental artifacts. C1 UNIV CALIF RIVERSIDE,DEPT CHEM,RIVERSIDE,CA 92521. LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,LOS ALAMOS,NM 87545. RI Moore, David/C-8692-2013 NR 49 TC 25 Z9 26 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 18 PY 1996 VL 100 IS 29 BP 11863 EP 11869 DI 10.1021/jp960447n PG 7 WC Chemistry, Physical SC Chemistry GA UX961 UT WOS:A1996UX96100009 ER PT J AU Lian, TQ Bromberg, SE Asplund, MC Yang, H Harris, CB AF Lian, TQ Bromberg, SE Asplund, MC Yang, H Harris, CB TI Femtosecond infrared studies of the dissociation and dynamics of transition metal carbonyls in solution SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID STIMULATED RAMAN-SCATTERING; RESOLVED IR SPECTROSCOPY; ULTRAFAST TIME SCALES; VIBRATIONAL-RELAXATION; TRANSIENT ABSORPTION; PHOTOGENERATED CR(CO)5(ROH); COHERENT PHOTOCHEMISTRY; RECOMBINATION DYNAMICS; HIGH-PRESSURES; M(CO)6 M=CR AB The ultrafast dynamics of the dissociation of M(CO)(6) (M = Cr, W, Mo) in alkane solutions were studied by femtosecond IR spectroscopy. After UV photolysis at 295 nm, both the bleach of the parent molecules and the absorption of the pentacarbonyl intermediate were probed with 240 fs time resolution. Oscillatory perturbed free induction decay signals before t = 0 were observed and well characterized by realistic parameters of the system. The bleach recovery dynamics were found to be wavelength dependent, indicating that hot parent molecules are formed rind that the bleach recovery time is determined by the vibrational cooling time. The measured percentage bleach recovery in n-heptane is less than the expected value calculated from the photosubstitution quantum yield measurements, suggesting that the initial recovery of the bleach is faster than our time resolution. The kinetics in the A(1) vibrational mode region of the pentacarbonyl species have been measured to probe the formation and decay of the nascent product. The absorption of the product rises with an instrument response limited rate indicating that the formation of the product is much faster than 240 fs. The long time kinetics in this region reflect the vibrational cooling of the product. A fast decay with time constant of less than 300 fs is present in all the wavelengths probed, and its spectrum appears to resemble the early time spectrum of the hot pentacarbonyl species. This fast decay, observed in all three different metal carbonyls, is attributed to the fast geminate recombination of the pentacarbonyl with photodissociated CO ligand after only one to two collisions with the solvent cage. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV CHEM SCI,BERKELEY,CA 94720. RI Lian, Tianquan/L-8992-2013 OI Lian, Tianquan/0000-0002-8351-3690 NR 87 TC 110 Z9 110 U1 0 U2 35 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 18 PY 1996 VL 100 IS 29 BP 11994 EP 12001 DI 10.1021/jp9618035 PG 8 WC Chemistry, Physical SC Chemistry GA UX961 UT WOS:A1996UX96100024 ER PT J AU Griffiths, JA ElSayed, MA Capel, M AF Griffiths, JA ElSayed, MA Capel, M TI Effect of binding of lanthanide ions on the bacteriorhodopsin hexagonal structure: An x-ray study SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID DIVALENT-CATION BINDING; ELECTRON-SPIN RESONANCE; PURPLE MEMBRANE; SITES; MECHANISM; TRANSITION; SURFACE; LIGHT; BLUE; PH AB The effect of the bind;ng of trivalent lanthanide metal cations (Eu3+, Ho3+, and Dy3+) on the hexagonal structure of bacteriorhodopsin (bR) is investigated at different pH using x-Ray diffraction to examine films made by slow evaporation of the corresponding regenerated bR. It is observed that the lanthanide-regenerated bR (at a ratio of 2:1 metal ion to bR) does not form a 2D structure isomorphous to that of native bR or Ca2+-regenerated samples at low sample pH. The native bR hexagonal structure is recovered by titration of the sample with sodium hydroxide. The pH at which the hexagonal structure is recovered depends on the charge density of the lanthanide ion used for the regeneration. The higher the charge density of the ion, the higher the pH at which an isomorphous lattice is formed. A model is proposed in which at normal or low pH a complex bidentate and monodentate type binding (which disrupts the lattice hexagonal structure) exists between a lanthanide ion, the O- of PO2- groups, and/or the amino acid residues. Ar high pH, complexation with OH- takes place, which converts this binding to a simple monodentate type complete that leads to the recovery of the lattice structure. An equation is derived for the pH at which this conversion takes place and is found to be proportional to the binding constant of the lanthanide ions to the O- of the PO2- groups or the amino acid residues and inversely proportional to the binding constant of the lanthanide ion to the OH- groups. This predicts an increase of conversion pH with the charge-density of the lanthanide ion, as observed. C1 GEORGIA INST TECHNOL,SCH CHEM & BIOCHEM,ATLANTA,GA 30332. BROOKHAVEN NATL LABS,DEPT BIOL,UPTON,NY. NR 49 TC 2 Z9 2 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 18 PY 1996 VL 100 IS 29 BP 12002 EP 12007 DI 10.1021/jp960741f PG 6 WC Chemistry, Physical SC Chemistry GA UX961 UT WOS:A1996UX96100025 ER PT J AU Wu, HM Savikhin, S Reddy, NRS Jankowiak, R Cogdell, RJ Struve, WS Small, GJ AF Wu, HM Savikhin, S Reddy, NRS Jankowiak, R Cogdell, RJ Struve, WS Small, GJ TI Femtosecond and hole-burning studies of B800's excitation energy relaxation dynamics in the LH2 antenna complex of Rhodopseudomonas acidophila (strain 10050) SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RHODOBACTER-SPHAEROIDES; PURPLE BACTERIA; BACTERIOCHLOROPHYLL-A; DISPERSIVE KINETICS; REACTION CENTERS; STATE; BACTERIOPHEOPHYTIN; SPECTROSCOPY; TRIMERS; SPECTRA AB One- and two-color pump/probe femtosecond and hole-burning data are reported for the isolated B800-850 (LH2) antenna complex of Rhodopseudomonas acidophila (strain 10050). The two-color profiles are interpretable in terms of essentially monophasic B800-->B850 energy transfer with kinetics ranging from 1.6 to 1.1 ps between 19 and 130 K for excitation at or to the red of the B800 absorption maximum. The B800 zero-phonon hole profiles obtained at 4.2 K with burn frequencies located near or to the red of this maximum yielded a transfer time of 1.8 ps. B800 hole-burning data (4.2 K) are also reported for chromatophores at ambient pressure and pressures of 270 and 375 MPa. At ambient pressure the B800-B850 energy gap is 950 cm(-1), while at 270 snd 375 MPa it is close to 1000 and 1050 cm(-1), respectively. However, no dependence of the B800-->B850 transfer time on pressure was observed, consistent with data for the B800-850 complex of Rhodobacter sphaeroides. The resilience of the transfer rate to pressure-induced changes in the energy gap and the weak temperature dependence of the rare are consistent with the model that has the spectral overlap (of Forster theory) provided by the B800 fluorescence origin band and weak vibronic absorption bands of B850. However, both the time domain and hole-burning data establish that there is an additional relaxation channel for B800, which is observed when excitation is located to the blue of the B800 absorption maximum. Several explanations fur this faster channel are considered, including that it is due to intra-B800 energy transfer or a manifestation of coupling of B800 with quasi-degenerate upper exciton levels of the B850 molecules. The data indicate that it is not due to vibrational relaxation. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. UNIV GLASGOW,DEPT BOT,GLASGOW G12 8QQ,LANARK,SCOTLAND. NR 40 TC 89 Z9 97 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 18 PY 1996 VL 100 IS 29 BP 12022 EP 12033 DI 10.1021/jp9608178 PG 12 WC Chemistry, Physical SC Chemistry GA UX961 UT WOS:A1996UX96100027 ER PT J AU Yaron, U Gammel, PL Ramirez, AP Huse, DA Bishop, DJ Goldman, AI Stassis, C Canfield, PC Mortensen, K Eskildsen, MR AF Yaron, U Gammel, PL Ramirez, AP Huse, DA Bishop, DJ Goldman, AI Stassis, C Canfield, PC Mortensen, K Eskildsen, MR TI Microscopic coexistence of magnetism and superconductivity in ErNi2B2C SO NATURE LA English DT Article ID VORTEX LATTICE AB MAGNETISM and superconductivity are manifestations of two different ordered states into which metals can condense at low temperatures. In general these states are mutually exclusive(1); they do not coexist at the same place in a sample. The study of the interplay between these properties has recently been revitalized by the discovery(2,3) of a class of compounds with formula RNi(2)B(2)C (where R is a rare-earth element) which are both antiferromagnetic and superconducting at sufficiently low temperature(4). It has been suggested(5) that magnetic and superconducting order can coexist in these materials on an atomic scale. Here we use small-angle neutron scattering to study the structure of the superconducting vortex lattice in ErNi2B2C. Our results show that the development of magnetic order causes the vortex lines to disorder and rotate away from the direction of the applied magnetic field. This coupling of superconductivity and magnetism provides clear evidence for microscopic coexistence of magnetic and superconducting order, and indicates that magnetic superconductors may exhibit a range of unusual phenomena not observed in conventional superconductors. C1 AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RISO NATL LAB,DK-4000 ROSKILDE,DENMARK. RI Mortensen, Kell/A-5066-2009; Eskildsen, Morten/E-7779-2011; Canfield, Paul/H-2698-2014 OI Mortensen, Kell/0000-0002-8998-9390; NR 14 TC 116 Z9 117 U1 0 U2 5 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD JUL 18 PY 1996 VL 382 IS 6588 BP 236 EP 238 DI 10.1038/382236a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UX790 UT WOS:A1996UX79000043 ER PT J AU Awes, TC Bock, D Bock, R Clewing, G Garpman, S Glasow, R Gustafsson, HA Gutbrod, HH Holker, G Jacobs, P Kampert, KH Kolb, BW Lister, T Lohner, H Lund, I Obenshain, FE Oskarsson, A Otterlund, I Peitzmann, T Plasil, F Poskanzer, AM Purschke, M Ritter, HG Santo, R Schmidt, HR Siemiarczuk, T Sorensen, SP Steffens, K Steinhaeuser, P Stenlund, E Stuken, D Young, GR AF Awes, TC Bock, D Bock, R Clewing, G Garpman, S Glasow, R Gustafsson, HA Gutbrod, HH Holker, G Jacobs, P Kampert, KH Kolb, BW Lister, T Lohner, H Lund, I Obenshain, FE Oskarsson, A Otterlund, I Peitzmann, T Plasil, F Poskanzer, AM Purschke, M Ritter, HG Santo, R Schmidt, HR Siemiarczuk, T Sorensen, SP Steffens, K Steinhaeuser, P Stenlund, E Stuken, D Young, GR TI Azimuthal correlations in the target fragmentation region of high energy nuclear collisions SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; TRANSVERSE ENERGY; COLLECTIVE FLOW; PION EMISSION; 200-A GEV; MATTER; DISTRIBUTIONS; MULTIPLICITY; COMPRESSION; DEPENDENCE AB Results on the target mass dependence of proton and pion pseudorapidity distributions and of their azimuthal correlations in the target rapidity range -1.73 less than or equal to eta less than or equal to 1.32 are presented. The data have been taken with the Plastic-Ball detector set-up for 4.9 GeV p+Au collisions at the Berkeley BEVALAC acid for 200 A . GeV/c p-, O-, and S-induced reactions on different nuclei at the CERN-SPS. The yield of protons at backward rapidities is found to be proportional to the target mass. Although protons show a typical ''back-to-back'' correlation, a ''side-by-side'' correlation is observed for positive pions, which increases both with target mass and with impact parameter of a collision. The data can consistently be described by assuming strong rescattering phenomena including pion absorption effects in the entire excited target nucleus. C1 GESELL SCHWERIONENFORSCH MBH,D-64220 DARMSTADT,GERMANY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. LUND UNIV,S-22362 LUND,SWEDEN. UNIV MUNSTER,D-48149 MUNSTER,GERMANY. UNIV GRONINGEN,KVI,NL-9747 AG GRONINGEN,NETHERLANDS. UNIV TENNESSEE,KNOXVILLE,TN 37996. RP Awes, TC (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Peitzmann, Thomas/K-2206-2012; Lohner, Herbert/B-2397-2014; OI Peitzmann, Thomas/0000-0002-7116-899X; Lohner, Herbert/0000-0002-7441-739X; Kampert, Karl-Heinz/0000-0002-2805-0195 NR 25 TC 13 Z9 13 U1 0 U2 1 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 JUL 18 PY 1996 VL 381 IS 1-3 BP 29 EP 34 DI 10.1016/0370-2693(96)00601-6 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA UY500 UT WOS:A1996UY50000006 ER PT J AU Elliott, JB Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, DA Chacon, AD Chance, JL Choi, Y Costa, S Gilkes, ML Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, JC Lindenstruth, V Lisa, MA Lynen, U Matis, HS McMahan, M McParland, C Muller, WFJ Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Sann, H Scharenberg, R Scott, A Shao, Y Srivastava, BK Symons, TJM Tincknell, M Tuve, C Wang, S Warren, P Wieman, HH Wolf, K AF Elliott, JB Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, DA Chacon, AD Chance, JL Choi, Y Costa, S Gilkes, ML Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, JC Lindenstruth, V Lisa, MA Lynen, U Matis, HS McMahan, M McParland, C Muller, WFJ Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Sann, H Scharenberg, R Scott, A Shao, Y Srivastava, BK Symons, TJM Tincknell, M Tuve, C Wang, S Warren, P Wieman, HH Wolf, K TI Individual fragment yields and determination of the critical exponent sigma SO PHYSICS LETTERS B LA English DT Article DE multifragmentation; critical exponents ID PROTON-NUCLEUS INTERACTIONS; PERCOLATION CLUSTERS; MULTIFRAGMENTATION; COLLISIONS; MATTER; XENON AB We have studied the yield of individual. fragments formed in the projectile fragmentation of gold nuclei at 1 AGeV incident on a carbon target as a function of the total charge multiplicity, The yields of fragments of different nuclear charge peak at different multiplicities, We show that this behavior can be used to determine the critical exponent a. We obtain a =0.68+/-0.05, consistent with the liquid-gas value. C1 UNIV CATANIA,I-95129 CATANIA,ITALY. IST NAZL FIS NUCL,SEZ CATANIA,I-95129 CATANIA,ITALY. UNIV CALIF DAVIS,DAVIS,CA 95616. GSI DARMSTADT,D-64220 DARMSTADT,GERMANY. KENT STATE UNIV,KENT,OH 44242. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP Elliott, JB (reprint author), PURDUE UNIV,W LAFAYETTE,IN 47907, USA. RI Insolia, Antonio/M-3447-2015; TUVE', Cristina/P-3933-2015 OI Insolia, Antonio/0000-0002-9040-1566; TUVE', Cristina/0000-0003-0739-3153 NR 26 TC 41 Z9 41 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 JUL 18 PY 1996 VL 381 IS 1-3 BP 35 EP 39 DI 10.1016/0370-2693(96)00590-4 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA UY500 UT WOS:A1996UY50000007 ER PT J AU Brodsky, SJ Ma, BQ AF Brodsky, SJ Ma, BQ TI The quark-antiquark asymmetry of the nucleon sea SO PHYSICS LETTERS B LA English DT Article ID GOTTFRIED SUM; WAVE-FUNCTION; STRANGE SEA; PROTON; ROTATION; CHARM; SPIN AB Although the distributions of sea quarks and antiquarks generated by leading-twist QCD evolution through gluon splitting g --> (q) over bar q are necessarily CP symmetric, the distributions of nonvalence quarks and antiquarks which are intrinsic to the nucleon's bound state wavefunction need not be identical. In this paper we investigate the sea quark-antiquark asymmetries in the nucleon wavefunction which are generated by a light-cone model of energetically-favored meson-baryon fluctuations. The model predicts striking quark-antiquark asymmetries in the momentum and helicity distributions for the down and strange contributions to the proton structure function: the intrinsic d and s quarks in the proton sea are predicted to be negatively polarized, whereas the intrinsic (d) over bar and (s) over bar antiquarks give zero contributions to the proton spin, Such a picture is supported by experimental phenomena related to the proton spin problem and the violation of the Ellis-Jaffe sum rule. The light-cone meson-baryon fluctuation model also suggests a structured momentum distribution asymmetry for strange quarks and antiquarks which could be relevant to an outstanding conflict between two different determinations of the strange quark sea in the nucleon. The model predicts an excess of intrinsic d (d) over bar pairs over u (u) over bar pairs, as supported by the Gottfried sum rule violation. We also predict that the intrinsic charm and anticharm helicity and momentum distributions are not identical. C1 CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R CHINA. ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING 100039,PEOPLES R CHINA. KWANGHUA ACAD SCI,FAC NAT SCI,BEIJING 100081,PEOPLES R CHINA. RP Brodsky, SJ (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 37 TC 215 Z9 218 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 JUL 18 PY 1996 VL 381 IS 1-3 BP 317 EP 324 DI 10.1016/0370-2693(96)00597-7 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA UY500 UT WOS:A1996UY50000047 ER PT J AU Casteel, WJ Dixon, DA Mercier, HPA Schrobilgen, GJ AF Casteel, WJ Dixon, DA Mercier, HPA Schrobilgen, GJ TI The osmium(VIII) oxofluoro cations OsO2F3+ and F(cis-OsO2F3)(2)(+): Syntheses, characterization by F-19 NMR spectroscopy and Raman spectroscopy, X-ray crystal structure of F(cis-OsO2F3)(2)(Sb2F11-)-Sb-+, and density functional theory calculations of OsO2F3, ReO2F3, and F(cis-OsO2F3)(2)(+) SO INORGANIC CHEMISTRY LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; OXIDE FLUORIDES; TETRAFLUORIDE DIOXIDE; MOLECULAR GEOMETRIES; XENON(II) COMPOUNDS; ENERGIES; ADDUCTS; APPROXIMATION; VIBRATIONS; CHEMISTRY AB Osmium dioxide tetrafluoride, cis-OsO2F4, reacts with the strong fluoride ion accepters AsF5 and SbF5 in anhydrous HF and SbF5 solutions to form orange salts. Raman spectra are consistent with the formation of the fluorine-bridged diosmium cation F(cis-OsO2F3)(2)(+), as the AsF6- and Sb2F11- salts, respectively. The F-19 NMR spectra of the salts in HF solution are exchange-averaged singlets occurring at higher frequency than those of the fluorine environments of cis-OsO2F4. The F(cis-OsO2F3)(2)(Sb2F11-)-Sb-+ salt crystallizes in the orthorhombic space group Imma. At -107 degrees C, a = 12.838(3) Angstrom, b = 10.667(2) Angstrom, c = 11.323(2) Angstrom, V = 1550.7(8) Angstrom(3), and Z = 4. Refinement converged with R = 0.0469 [R(w) = 0.0500]. The crystal structure consists of discrete fluorine-bridged F(cisOsO(2)F(3))(2)(+) and Sb2F11- ions in which the fluorine bridge of the F(cis-OsO2F3)(2)(+) cation is trans to an oxygen atom (Os-O 1.676 Angstrom) of each OsO2F3 group. The angle at the bridge is 155.2(8)degrees with a bridging Os-F-b distance of 2.086(3) Angstrom. Two terminal fluorine atoms (Os-F 1.821 Angstrom) are cis to the two oxygen atoms (Os-O 1.750 Angstrom), and two terminal fluorine atoms of the OsO2F3 group are trans to one another (1.813 Angstrom). The OsO2F3+ cation was characterized by F-19 NMR and by Raman spectroscopy in neat SbF5 solution but was not isolable in the solid state. The NMR and Raman spectroscopic findings are consistent with a trigonal bipyramidal cation in which the oxygen atoms and a fluorine atom occupy the equatorial plane and two fluorine atoms are in axial positions. Density functional theory calculations show that the crystallographic structure of F(Cis-OSO2F3)(2)(+) is the energy-minimized structure and the energy-minimized structures of the OsO2F3+ cation and ReO2F3 are trigonal bipyramidal having C-2 nu point symmetry. Attempts to prepare the OsOF5+ cation by oxidative fluorination of cis-OsO2F4 with KrF(+)ASF(6)(-) in anhydrous HF proved unsuccessful. C1 MCMASTER UNIV, DEPT CHEM, HAMILTON, ON L8S 4M1, CANADA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 79 TC 47 Z9 47 U1 1 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 EI 1520-510X J9 INORG CHEM JI Inorg. Chem. PD JUL 17 PY 1996 VL 35 IS 15 BP 4310 EP 4322 DI 10.1021/ic951059n PG 13 WC Chemistry, Inorganic & Nuclear SC Chemistry GA UX980 UT WOS:A1996UX98000005 ER PT J AU Ellerby, LM Cabelli, DE Graden, JA Valentine, JS AF Ellerby, LM Cabelli, DE Graden, JA Valentine, JS TI Copper-zinc superoxide dismutase: Why not pH-dependent? SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PULSE-RADIOLYSIS; MECHANISM; RADICALS; COMPLEXES; MUTANTS; RESONANCE; OXIDATION; BINDING AB Copper-zinc superoxide dismutase (CuZnSOD) catalyzes the disproportionation of superoxide to hydrogen peroxide and dioxygen at diffusion controlled rates, Previous mechanistic studies have focused on the dramatic electrostatic guidance mechanism by which superoxide is drawn into the active site of this enzyme. Another striking bur: less understood feature of this enzyme is its ability to dismutate superoxide over a wide range of pH (5-9.5) without any change in rate-determining step or structural changes at the active site copper. To investigate the explanation for this pH independence, we have redetermined the rate: of superoxide disproportionation, k(cat), catalyzed by the zinc-deficient form (Cu-apoSOD) of the enzyme as a function of pH and have found that it is pH-dependent, in contrast to the native enzyme, even under conditions in which the topper ion does not leave the native copper-binding site, In addition, we have determined the rare of reduction, k(1), of Cu-apoSOD by superoxide and have found that this step of the catalytic cycle is pH-independent. We conclude that the reoxidation rate, k(2), of the catalytic cycle is pH-dependent for Cu-apoSOD. These results have led us to propose that the key role of the zinc and of the hist idyl imidazolate that bridges copper and zinc in CuZnSOD is to aid in the rapid dissociation of the product peroxide. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90095. RI Valentine, Joan/B-6665-2008 OI Valentine, Joan/0000-0002-7174-925X NR 44 TC 110 Z9 110 U1 1 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 17 PY 1996 VL 118 IS 28 BP 6556 EP 6561 DI 10.1021/ja953845x PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA UX673 UT WOS:A1996UX67300004 ER PT J AU Greenfield, SR Svec, WA Gosztola, D Wasielewski, MR AF Greenfield, SR Svec, WA Gosztola, D Wasielewski, MR TI Multistep photochemical charge separation in rod-like molecules based on aromatic imides and diimides SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHOTOINDUCED ELECTRON-TRANSFER; PHOTOSYNTHETIC REACTION-CENTER; ION-PAIR FORMATION; BACTERIAL REACTION CENTERS; FIXED-DISTANCE TRIADS; ZINC PORPHYRIN; BIOLOGICAL MOLECULES; ACCEPTOR SYSTEM; INVERTED REGION; QUINONE TRIADS AB A series of intramolecular triads with Linear, rod-like structures has been developed that undergo very efficient two-step electron transfer following direct excitation of a chromophore possessing a charge transfer (CT) excited state. The CT state of 4-aminonaphthalene-1,8-imide (ANI), produced by direct excitation of the chromophore, has about 70% of a negative charge transferred from the amine to the imide. Attachment of aniline (An) and p-methoxyaniline (MeOAn) donors to ANI by means of a piperazine bridge results in linear dyads, An-ANI and MeOAn-ANI, that undergo rapid electron transfer in about 10(-11) s to give a >99% yield of the ion pairs, An(+)-ANI(-) and MeOA(n)+-ANI(-), in which the charges are separated by 7.7 Angstrom. The formation and decay of these ion pairs can be monitored directly by transient absorption spectroscopy. Further attachment of a 1,8:4,5-naphthalenediimide (NI) electron acceptor to the imide group of ANI using a 2,5-dimethylphenyl spacer results in triads An-ANI-NI and MeOAn-ANI-NI. Excitation of the CT state of ANI within these triads results in the same high yield charge separation step observed in the corresponding dyads followed by a subnanosecond charge shift reaction to yield the giant dipole states An(+)-ANI-NI- and MeOAn(+)-ANI-NI- in 72% and 92% yield, respectively, in toluene. The lifetime of MeOAn(+)-ANI-NI- is 310 ns. These triad molecules make explicit use of a CT excited state to initiate a multistep electron transfer process. The excited singlet CT state and the two ion pair states are all spectroscopically distinct, and all states are unambiguously spectrally resolved by transient absorption measurements. In addition, the ion pair states An(+)-ANI(-) and MeOAn(+)-ANI(-) undergo radiative recombination, thereby allowing a more detailed analysis of the energetics of charge separation and the influence of the CT excited state on the rates of subsequent longer distance charge shift reactions in these molecules. C1 ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. NORTHWESTERN UNIV, DEPT CHEM, EVANSTON, IL 60208 USA. RI Gosztola, David/D-9320-2011 OI Gosztola, David/0000-0003-2674-1379 NR 66 TC 221 Z9 223 U1 2 U2 32 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 JUL 17 PY 1996 VL 118 IS 28 BP 6767 EP 6777 DI 10.1021/ja9600789 PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA UX673 UT WOS:A1996UX67300029 ER PT J AU Arney, DSJ Schnabel, RC Scott, BC Burns, CJ AF Arney, DSJ Schnabel, RC Scott, BC Burns, CJ TI Preparation of actinide phosphinidene complexes: Steric control of reactivity SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID H BOND ACTIVATION; X-RAY STRUCTURE; CATALYTIC HYDROAMINATION; TUNGSTEN COMPLEXES; CHEMISTRY; PHOSPHORUS; LIGANDS; ALKYNES; GENERATION; PHOSPHIDO C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. NR 44 TC 63 Z9 63 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 17 PY 1996 VL 118 IS 28 BP 6780 EP 6781 DI 10.1021/ja960221y PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA UX673 UT WOS:A1996UX67300031 ER PT J AU King, WA Luo, XL Scott, BL Kubas, GJ Zilm, KW AF King, WA Luo, XL Scott, BL Kubas, GJ Zilm, KW TI Cationic manganese(I) dihydrogen and dinitrogen complexes derived from a formally 16-electron complex with a bis-agostic interaction, [Mn(CO)(Ph(2)PC(2)H(4)PPh(2))(2)](+) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLECULAR-HYDROGEN COMPLEXES; REACTION COORDINATE; SIGMA-BONDS; ETA(2)-DIHYDROGEN; DIHYDRIDE; CLEAVAGE; LIGANDS C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. YALE UNIV,DEPT CHEM,NEW HAVEN,CT 06520. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 21 TC 60 Z9 60 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 17 PY 1996 VL 118 IS 28 BP 6782 EP 6783 DI 10.1021/ja960499q PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA UX673 UT WOS:A1996UX67300032 ER PT J AU McAteer, K Kennedy, MA Jing, YQ Taylor, JS AF McAteer, K Kennedy, MA Jing, YQ Taylor, JS TI 750 MHz NMR study of the structure of a DNA dodecamer duplex containing a cis-syn thymine dimer. SO BIOCHEMISTRY LA English DT Meeting Abstract C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. WASHINGTON UNIV, DEPT CHEM, ST LOUIS, MO 63130 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 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 16 PY 1996 VL 35 IS 28 BP 6 EP 6 PG 1 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UX738 UT WOS:A1996UX73800040 ER PT J AU Larimer, FW Lu, TYS Stringer, CD AF Larimer, FW Lu, TYS Stringer, CD TI Construction, purification, and characterization of recombinant D-ribulose-5-phosphate 3-epimerase from spinacia oleracea. SO BIOCHEMISTRY LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,DIV BIOL,PROT ENGN PROGRAM,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 16 PY 1996 VL 35 IS 28 BP 48 EP 48 PG 1 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UX738 UT WOS:A1996UX73800081 ER PT J AU Harpel, MR Hartman, FC AF Harpel, MR Hartman, FC TI Proton transfer reactions of ribulose-1,5-bisphosphate (RuBP) carboxylase/oxygenase. SO BIOCHEMISTRY LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,DIV BIOL,PROT ENGN PROGRAM,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 16 PY 1996 VL 35 IS 28 BP 51 EP 51 PG 2 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UX738 UT WOS:A1996UX73800084 ER PT J AU Chance, MR Miller, LM Fischetti, RF Scheuring, E Huang, WX Sclavi, B Hai, Y Sullivan, M AF Chance, MR Miller, LM Fischetti, RF Scheuring, E Huang, WX Sclavi, B Hai, Y Sullivan, M TI Global mapping of structural solutions provided by the extended x-ray absorption fine structure ab initio code FEFF 6.01: Structure of the cryogenic photoproduct of the myoglobin carbon monoxide complex SO BIOCHEMISTRY LA English DT Article ID RESONANCE RAMAN-SPECTRA; HEME-PROTEINS; MULTIPLE-SCATTERING; LOW-TEMPERATURE; LIGAND-BINDING; INFRARED-SPECTROSCOPY; EXAFS ANALYSIS; CARBOXYMYOGLOBIN; HEMOGLOBIN; DYNAMICS AB X-ray methods based on synchrotron technology have the promise of providing time-resolved structural data based on the high flux and brightness of the X-ray beams. One of the most closely examined problems in this area of time-resolved structure determination has been the examination of intermediates in ligand binding to myoglobin, Recent crystallographic experiments using synchrotron radiation have identified the protein tertiary and heme structural changes that occur upon photolysis of the myoglobin-carbon monoxide complex at cryogenic temperatures [Schlichting, I., Berendzen, J., Phillips, G,, & Sweet, R. (1994) Nature 371, 808-812]. However, the precision of protein crystallographic data (similar to 0.2 Angstrom) is insufficient to provide precise metrical details of the iron-ligand bond lengths. Since bond length changes on this scale can trigger reactivity changes of several orders of magnitude, such detail is critical to a full understanding of metalloprotein structure-function relationships, Extended X-ray absorption fine structure (EXAFS) spectroscopy has the potential for analyzing bond distances to a precision of 0.02 Angstrom but is hampered by its relative insensitivity to the geometry of the backscattering atoms. Thus, it is often unable to provide a unique solution to the structure without ancillary structural information. We have developed a suite of computer programs that incorporate this ancillary structural information and compute the expected experimental spectra for a wide ranging series of Cartesian coordinate sets (global mapping), The programs systematically increment the distance of the metal to various coordinating ligands (along with their associated higher shells), Then, utilizing the ab initio EXAFS code FEFF 6.01, simulated spectra are generated and compared to the actual experimental spectra, and the differences are computed, Finally, the results for hundreds of simulations can be displayed (and compared) in a single plot. The power of this approach is demonstrated in the examination of high signal to noise EXAFS data from a photolyzed solution sample of the myoglobin-carbon monoxide complex at 10 K. Evaluation of these data using our global mapping procedures placed the iron to pyrrole nitrogen average distances close to the value for deoxymyoglobin (2.05 +/- 0.01 Angstrom), while the distance from iron to the proximal histidine nitrogen is seen to be 2.20 +/- 0.04 Angstrom. It is also shown that one cannot uniquely position the CO ligand on the basis of the EXAFS data alone, as a number of reasonable minima (from the perspective of the EXAFS) are observed. This provides a reasonable explanation for the multiplicity of solutions that have been previously reported. The results presented here are seen to be in complete agreement with the crystallographic results of Schlichting et al. (1994) within the respective errors of the two techniques; however, the extended X-ray absorption fine structure data allow the iron-ligand bond lengths to be precisely defined. An examination of the available spectroscopic data, including EXAFS, shows that the crystallographic results of Schlichting et al. (1994) are highly relevant to the physiological solution state and must be taken into account in any attempt to understand the incomplete relaxation process of the heme iron for the Mb*CO photoproduct at low temperature. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RP Chance, MR (reprint author), YESHIVA UNIV ALBERT EINSTEIN COLL MED,DEPT PHYSIOL & BIOPHYS,BRONX,NY 10461, USA. RI sclavi, bianca/F-8536-2010 FU NCRR NIH HHS [P41-RR01633, RR-01633]; NHLBI NIH HHS [HL-45892] NR 66 TC 28 Z9 28 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 16 PY 1996 VL 35 IS 28 BP 9014 EP 9023 DI 10.1021/bi9605503 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UX738 UT WOS:A1996UX73800003 PM 8703904 ER PT J AU Cheng, XH Morin, PE Harms, AC Bruce, JE BenDavid, Y Smith, RD AF Cheng, XH Morin, PE Harms, AC Bruce, JE BenDavid, Y Smith, RD TI Mass spectrometric characterization of sequence-specific complexes of DNA and transcription factor PU.1 DNA binding domain SO ANALYTICAL BIOCHEMISTRY LA English DT Article ID ELECTROSPRAY-IONIZATION; OLIGONUCLEOTIDE DUPLEX; BIOMOLECULES; PRINCIPLES; PROTEINS AB Electrospray ionization mass spectrometry (ESI-MS) has been used to study the noncovalent interaction of the 13.5-kDa DNA binding domain of PU.1 (PU.1-DBD) with specific double-stranded DNA (dsDNA) target molecules. Mixtures of PU.1-DBD protein and wildtype target DNA sequence yielded ESI-MS spectra showing only protein-dsDNA complex ions of 1:1 stoichiometry and free dsDNA. When PU.1-DBD protein, wild type target DNA, and a mutant target DNA lacking the consensus sequence were mixed, only the 1:1 complex with the wild-type DNA was observed, consistent with gel electrophoresis mobility shift assay results, demonstrating the observation of sequence-specific protein-dsDNA complexes using ESI-MS. (C) 1996 Academic Press, Inc. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. UNIV TORONTO, DEPT MED BIOPHYS, TORONTO, ON M5G 2M9, CANADA. ONTARIO CANC INST, TORONTO, ON M5G 2M9, CANADA. UNIV TORONTO, SUNNY BROOK MED SCI CTR, DEPT CANC RES, TORONTO, ON M4N 3M5, CANADA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 22 TC 55 Z9 60 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD JUL 15 PY 1996 VL 239 IS 1 BP 35 EP 40 DI 10.1006/abio.1996.0287 PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA UY648 UT WOS:A1996UY64800005 PM 8660622 ER PT J AU Sutherland, BM Bennett, PV Sutherland, JC AF Sutherland, BM Bennett, PV Sutherland, JC TI Double strand breaks induced by low doses of gamma rays or heavy ions: Quantitation in nonradioactive human DNA SO ANALYTICAL BIOCHEMISTRY LA English DT Article ID FIELD GEL-ELECTROPHORESIS; NEUTRAL FILTER ELUTION; BROMIDE-STAINED DNA; HIGH-ENERGY NEON; HUMAN FIBROBLASTS; MAMMALIAN-CELLS; CHROMATIN STRUCTURE; IONIZING-RADIATION; CHEF ELECTROPHORESIS; AGAROSE GELS AB We have developed a method of quantitating low frequencies (0-30 sites/10(9) base pairs) of double strand breaks in similar to 1 mu g of nonradioactive human DNA. Unirradiated or irradiated DNA is digested with the restriction endonuclease NotI, producing cleavage fragments that include a major group centered at similar to 1.2-1.3 Mbp. The DNA molecules are separated as a function of size by transverse alternating field electrophoresis. The frequency of double strand breaks is computed directly from the decrease in number average molecular length induced in the 1.2- to 1.3-Mbp cleavage fragment group by Cs-137 gamma or Fe26+ (1.1 GeV/nucleon) irradiation vs the corresponding unirradiated DNA samples. The double strand break frequency can be quantitated easily in the dose range of 0-10 cGy of gamma rays. The frequency of breaks per unit dose calculated for gamma irradiation of DNA in human cells (similar to 4.6 double strand breaks/10(9) bp/Gy) is within the range of values obtained by others (2-8 sites/10(9) bp/Gy) who used methods requiring higher doses. (C) 1996 Academic Press, Inc. RP BROOKHAVEN NATL LAB, DEPT BIOL, UPTON, NY 11973 USA. FU NHGRI NIH HHS [HG00371] NR 55 TC 19 Z9 21 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-2697 EI 1096-0309 J9 ANAL BIOCHEM JI Anal. Biochem. PD JUL 15 PY 1996 VL 239 IS 1 BP 53 EP 60 DI 10.1006/abio.1996.0290 PG 8 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA UY648 UT WOS:A1996UY64800008 PM 8660625 ER PT J AU Fornstedt, T Zhong, GM Bensetiti, Z Guiochon, G AF Fornstedt, T Zhong, GM Bensetiti, Z Guiochon, G TI Experimental and theoretical study of the adsorption behavior and mass transfer kinetics of propranolol enantiomers on cellulase protein as the selector SO ANALYTICAL CHEMISTRY LA English DT Article ID CHIRAL STATIONARY PHASES; NONLINEAR CHROMATOGRAPHY; ALPHA-1-ACID GLYCOPROTEIN; PHARMACOKINETIC DATA; CELLOBIOHYDROLASE-I; SERUM-ALBUMIN; SEPARATION; RESOLUTION; REGRESSION; PROFILES AB The thermodynamics and mass transfer kinetics of the retention of the R and S enantiomers of propranolol were investigated on a system comprising an acetic acid buffer solution as the mobile phase and the protein cellobiohydrolase I immobilized on silica as the stationary phase. The bi-langmuir isotherm model fitted best to each set of single-component isotherm data. The monolayer capacity of the nonchiral type of adsorption sites was 22.9 mM. For the chiral type of sites, it was 0.24 mM for the R enantiomer and 0.64 mM for the S enantiomer, Peak tailing was observed, even at very low concentrations allowing operation of the low-capacity chiral sites under linear conditions. This tailing can be explained on the basis of heterogeneous mass transfer kinetics. At higher concentrations, which are often used in analytical applications, the isotherms on the chiral sites no longer have a linear behavior, and peak tailing is consequently more pronounced, Under those conditions, peak tailing originates from the combined effect of heterogeneous thermodynamics and heterogeneous mass transfer kinetics. These complex phenomena are explained and modeled using the transport-dispersive model with a solid film linear driving force model modified to account for heterogeneous mass transfer kinetics. The rate coefficient of the mass transfer kinetics was found to be concentration dependent. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. UNIV UPPSALA,BMC,DEPT PHARMACEUT ANALYT CHEM,S-75123 UPPSALA,SWEDEN. OI Fornstedt, Torgny/0000-0002-7123-2066 NR 35 TC 63 Z9 63 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUL 15 PY 1996 VL 68 IS 14 BP 2370 EP 2378 DI 10.1021/ac960088s PG 9 WC Chemistry, Analytical SC Chemistry GA UY087 UT WOS:A1996UY08700014 PM 8686929 ER PT J AU Jellison, GE Modine, FA AF Jellison, GE Modine, FA TI Parameterization of the optical functions of amorphous materials in the interband region SO APPLIED PHYSICS LETTERS LA English DT Article ID SPECTROSCOPIC ELLIPSOMETRY AB A parameterization of the optical functions of amorphous semiconductors and insulators is presented in which the imaginary part of the dielectric function epsilon(2) is determined by multiplying the Tauc joint density of states by the epsilon(2) Obtained from the Lorentz oscillator model. The real part of the dielectric function epsilon(1) is calculated from epsilon(2) using Kramers-Kronig integration. The parameters of this model are fit to n and k data for amorphous Si (2 data sets), SiO, As2S3, and Si3N4 Comparative fits are made with a similar parameterization presented earlier by Forouhi and Bloomer [Phys. Rev. B 34, 7018 (1986)]. In all cases, the new parameterization fits the data better. (C) 1996 American Institute of Physics. RP Jellison, GE (reprint author), OAK RIDGE NATL LAB, DIV SOLID STATE, POB 2008, OAK RIDGE, TN 37831 USA. NR 20 TC 1215 Z9 1221 U1 12 U2 122 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 15 PY 1996 VL 69 IS 3 BP 371 EP 373 DI 10.1063/1.118064 PG 3 WC Physics, Applied SC Physics GA UW820 UT WOS:A1996UW82000030 ER PT J AU Shao, XM Holden, DN Rhodes, CT AF Shao, XM Holden, DN Rhodes, CT TI Broadband radio interferometry for lightning observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIATION AB A broad band radio interferometer for locating lightning emissions has been designed, constructed and tested. For a broad band interferometer, a single fixed pair of antennas is equivalent to having many baselines in a narrow band interferometer. So, a broad band system requires fewer antennas than a narrow band system to achieve equivalent angular resolution. In addition, frequency dependent locations of the radio emissions can be extracted for a more detailed look at the lightning breakdown processes. Such a system has been tested by a computer simulation and by measuring a man-made broad band radiation source. The system consists of two antennas which are separated vertically. Bandwidth of the system is from 40 to 350 MHz. Measurements of the man-made source indicate that with a signal-to-noise ratio (SNR) above 10 dB, the system is able to locate the source with an accuracy of about 2 degrees over the detectable frequencies. Preliminary observations of lightning discharges with this new technique appear to indicate that breakdown processes of a dart leader to: ground radiate Solely at its descending tip. RP Shao, XM (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87544, USA. NR 10 TC 35 Z9 44 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 15 PY 1996 VL 23 IS 15 BP 1917 EP 1920 DI 10.1029/96GL00474 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UY592 UT WOS:A1996UY59200007 ER PT J AU Bryant, CH Davies, PB Sears, TJ AF Bryant, CH Davies, PB Sears, TJ TI The N-2 pressure broadening coefficient of the J=1<-0 transition of (HCl)-H-1-Cl-35 measured by tunable far infrared (TuFIR) spectroscopy SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SUBMILLIMETER; LINE; HCL AB A tunable far infrared (TuFIR) laser sideband spectrometer has been used to determine the N-2 pressure broadening coefficient of the lowest rotational transition of (HCl)-H-1-Cl-35 between 0 and 1.8 Torr at room temperature (298 K). The parameters defining a Voigt lineshape were fitted to the J = 1 <-- 0 transition using a Levenberg-Marquardt non-linear least squares fitting routine. The average No broadening coefficient of the three components was determined to be 4.10(10)/(MHz/Torr), 0.104(2)/(cm(-1)/atm). C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Bryant, CH (reprint author), UNIV CAMBRIDGE,DEPT CHEM,LENSFIELD RD,CAMBRIDGE CB2 1EW,ENGLAND. RI Sears, Trevor/B-5990-2013 OI Sears, Trevor/0000-0002-5559-0154 NR 19 TC 4 Z9 4 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 15 PY 1996 VL 23 IS 15 BP 1945 EP 1947 DI 10.1029/96GL01766 PG 3 WC Geosciences, Multidisciplinary SC Geology GA UY592 UT WOS:A1996UY59200014 ER PT J AU Faldowski, JA Motta, AT Howe, LM Okamoto, PR AF Faldowski, JA Motta, AT Howe, LM Okamoto, PR TI Effect on electron energy on amorphization of ZrCr2 SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID IRRADIATION; KINETICS AB The influence of electron energy on the amorphization of ZrCr2 at 25 K was measured. Amorphization was observed at electron energies from 900 to 330 keV. The dose-to-amorphization increases with decreasing electron energy with two steps, one at 700 keV corresponding to the decrease in the Zr displacement cross section due to the approaching displacement threshold of Zr and one at 500 keV corresponding to an appreciable decrease in the displacement cross section of Cr due to the approaching displacement threshold for Cr. At lower electron energies, it is believed that amorphization occurs principally through a secondary displacement mechanism, where light impurity atoms (mainly O) are displaced by electrons and displace in turn the heavier atoms. By fitting the results using electron displacement cross sections, we find the displacement energies in each sublattice to be E(d)(Zr) = 22 eV, E(d)(Cr) = 23 eV, E(d)(O) = 4 eV. (C) 1996 American Institute of Physics. C1 ATOM ENERGY CANADA LTD,CHALK RIVER LABS,CHALK RIVER,ON K0J 1J0,CANADA. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Faldowski, JA (reprint author), PENN STATE UNIV,DEPT NUCL ENGN,UNIVERSITY PK,PA 16802, USA. NR 15 TC 4 Z9 4 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 15 PY 1996 VL 80 IS 2 BP 729 EP 733 DI 10.1063/1.362919 PG 5 WC Physics, Applied SC Physics GA UX156 UT WOS:A1996UX15600016 ER PT J AU Taga, N Odaka, H Shigesato, Y Yasui, I Kamei, M Haynes, TE AF Taga, N Odaka, H Shigesato, Y Yasui, I Kamei, M Haynes, TE TI Electrical properties of heteroepitaxial grown tin-doped indium oxide films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID YTTRIA-STABILIZED ZIRCONIA; OPTICAL-PROPERTIES; THIN-FILMS; LARGE-SCALE; DEPOSITION; TRANSPORT; IN2O3 AB Oriented thin-film tin-doped indium oxide (ITO) was heteroepitaxically grown on optically polished (100) or (111) planes of single-crystalline yttria-stabilized zirconia (YSZ) substrate using e-beam evaporation or dc magnetron sputtering techniques. Pole figure x-ray diffraction analyses revealed that the heteroepitaxial relations were (001)ITO parallel to(001)YSZ, [100]ITO parallel to[100]YSZ, and (111)ITO parallel to(111)YSZ, [110]ITO parallel to[110]YSZ, respectively. X-ray rocking curve analyses and Rutherford backscattering spectrometry revealed that the e-beam evaporated heteroepitaxial ITO films had much higher crystallinity than the one deposited by de magnetron sputtering. Both carrier density and Hall mobility of the e-beam evaporated heteroepitaxial films showed steady increases in a wide temperature range, which could be interpreted in terms of the increasing Sn-doping efficiency caused by the improvement of the crystallinity of In2O3 host lattice, and hence the decreasing Sn-based neutral scattering centers. (C) 1996 Anerican Institute of Physics. C1 UNIV TOKYO,INST IND SCI,MINATO KU,TOKYO 106,JAPAN. SCI UNIV TOKYO,DEPT MAT SCI & TECHNOL,NODA,CHIBA 278,JAPAN. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Taga, N (reprint author), ASAHI GLASS CO LTD,RES CTR,KANAGAWA KU,1150 HAZAWA CHO,YOKOHAMA,KANAGAWA 221,JAPAN. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 36 TC 63 Z9 67 U1 0 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 15 PY 1996 VL 80 IS 2 BP 978 EP 984 DI 10.1063/1.362910 PG 7 WC Physics, Applied SC Physics GA UX156 UT WOS:A1996UX15600051 ER PT J AU Su, ZP Rodrigues, PAM Yu, PY Risbud, SH AF Su, ZP Rodrigues, PAM Yu, PY Risbud, SH TI Selenium molecules and their possible role in deep emission from glasses doped with selenide nanocrystals SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SEMICONDUCTOR; SPECTRA AB We report the observation of Raman scattering from a vibration mode with frequency of 320 cm(-1) and its higher-order harmonics in silicate glasses doped with selenide semiconductor nanocrystals such as CdSe and ZnSe. Comparison with Raman spectra of glasses and alkali halides doped with Se suggests that these modes are caused by the presence or selenium molecules in the glasses; When excited in the blue and. green by an Ar+ laser, glasses containing Se only are found to emit strong near-infrared luminescence whose peak and Line shape are very similar to the so-called ''deep emission'' observed frequently from selenide-doped glasses. Possible effects of Se molecules on the linear and nonlinear optical properties of glasses containing selenide nanocrystals are discussed. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LABS,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT CHEM ENGN & MAT SCI,DIV ENGN & MAT SCI,DAVIS,CA 95616. RP Su, ZP (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Rodrigues, P. A. M./B-1498-2017 OI Rodrigues, P. A. M./0000-0003-2712-7549 NR 18 TC 17 Z9 17 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 15 PY 1996 VL 80 IS 2 BP 1054 EP 1057 DI 10.1063/1.362840 PG 4 WC Physics, Applied SC Physics GA UX156 UT WOS:A1996UX15600064 ER PT J AU Bechinger, C Bullock, JN Zhang, JG Tracy, CE Benson, DK Deb, SK Branz, HM AF Bechinger, C Bullock, JN Zhang, JG Tracy, CE Benson, DK Deb, SK Branz, HM TI Low-voltage electrochromic device for photovoltaic-powered smart windows SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SPECTROSCOPY; SYSTEMS; FILMS AB We report the properties of an all-solid-state electrochromic (EC) device that can be switched over a useful range of optical transmissions with voltages below 1 V. This switching voltage is smaller than required by other solid-state EC devices reported to date. Ww attribute the lower-than-normal switching voltage so the use of a thermally evaporated MgF2 thin film as the lithium ion conducting layer. Electrochemical impedance spectroscopy studies show that high lithium ion conductivity and low interfacial barriers for lithium exchange with the adjacent electrochromic and ion storage layers make MgF2 a good choice for the ion conductor in EC devices. This reduction in switching voltage is a first step toward powering an EC device by an integrated semitransparent single-junction photovoltaic (PV) cell. In a side-by-side bench test, where the EC device is connected to a semitransparent a-SiC:H PV cell having on open circuit voltage of 0.87 V, a relative transmission change in the EC device of 40% is achieved in less than 60 s. (C) 1996 American Institute of Physics. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. NR 32 TC 42 Z9 42 U1 4 U2 23 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 15 PY 1996 VL 80 IS 2 BP 1226 EP 1232 DI 10.1063/1.363731 PG 7 WC Physics, Applied SC Physics GA UX156 UT WOS:A1996UX15600090 ER PT J AU Huang, YH Iyengar, SS Kouri, DJ Hoffman, DK AF Huang, YH Iyengar, SS Kouri, DJ Hoffman, DK TI Further analysis of solutions to the time-independent wave packet equations of quantum dynamics .2. Scattering as a continuous function of energy using finite, discrete approximate Hamiltonians SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LIPPMANN-SCHWINGER EQUATIONS; DEPENDENT SCHRODINGER-EQUATION; ABSORBING BOUNDARY-CONDITIONS; VARIABLE REPRESENTATION; SURFACE; ACCURATE; H-3 AB We consider further how scattering information (the S-matrix) can be obtained, as a continuous function of energy, by studying wave packet dynamics on a finite grid of restricted size. Solutions are expanded using recursively generated basis functions for calculating Green's functions and the spectral density operator. These basis functions allow one to construct a general solution to both the standard homogeneous Schrodinger's equation and the time-independent wave packet, inhomogeneous Schrodinger equation, in the non-interacting region (away from the boundaries and the interaction region) from which the scattering solution obeying the desired boundary conditions can be constructed. In addition, we derive new expressions for a ''remainder or error term,'' which can hopefully be used to optimize the choice of grid points at which the scattering information is evaluated. Problems with reflections at finite boundaries are dealt with using a Hamiltonian which is damped in the boundary region as was done by Mandelshtam and Taylor [J. Chem. Phys. 103, 2903 (1995)]. This enables smaller Hamiltonian matrices to be used. The analysis and numerical methods are illustrated by application to collinear H+H-2 reactive scattering. (C) 1996 American Institute of Physics. C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP Huang, YH (reprint author), UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204, USA. RI Iyengar, Srinivasan/B-5570-2017 OI Iyengar, Srinivasan/0000-0001-6526-2907 NR 32 TC 71 Z9 71 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 15 PY 1996 VL 105 IS 3 BP 927 EP 939 DI 10.1063/1.471936 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UW836 UT WOS:A1996UW83600006 ER PT J AU Wyslouzil, BE Wilemski, G AF Wyslouzil, BE Wilemski, G TI Binary nucleation kinetics .3. Transient behavior and time lags SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DEPENDENT NUCLEATION; HOMOGENEOUS NUCLEATION; INDUCTION TIME; SULFURIC-ACID; VAPOR; WATER AB Transient binary nucleation is more complex than unary because of the bidimensionality of the cluster formation kinetics. To investigate this problem qualitatively and quantitatively, we numerically solved the birth-death equations for vapor-to-liquid phase transitions. Our previous work [J. Chem. Phys 103, 1137 (1995)] showed that the customary saddle point and growth path approximations are almost always valid in steady state gas phase nucleation and only fail if the nucleated solution phase is significantly nonideal. The current work demonstrates that in its early transient stages, binary nucleation rarely, if ever, occurs via the saddle point. This affects net only the number of particles forming but their composition and may be important for nucleation in glasses and other condensed mixtures for which time scales are very long. Before reaching the state of saddle point nucleation, most binary systems pass through a temporary stage in which the region of maximum flux extends over a ridge on the free energy surface. When ridge crossing nucleation is the steady state solution, it thus arises quite naturally as an arrested intermediate state that normally occurs in the development of saddle point nucleation. While the time dependent and steady state distributions of the fluxes and concentrations for each binary system are strongly influenced by the gas composition and species impingement rates, the ratio of nonequilibrium to equilibrium concentrations has a quasiuniversal behavior that is determined primarily by the thermodynamic properties of the liquid mixture. To test our quantitive understanding of the transient behavior, we directly calculated the time lag for the saddle point flux and compared it with the available analytical predictions. Although the analytical results overestimate the time lag by factors of 1.2-5, they should be adequate for purposes of planning experiments. We also found that the behavior of the saddle point time lag can indicate when steady state ridge crossing nucleation will occur. (C) 1996 American Institute of Physics. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Wyslouzil, BE (reprint author), WORCESTER POLYTECH INST,DEPT CHEM ENGN,WORCESTER,MA 01609, USA. RI Wyslouzil, Barbara/G-8219-2012 NR 46 TC 45 Z9 45 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 15 PY 1996 VL 105 IS 3 BP 1090 EP 1100 DI 10.1063/1.471953 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UW836 UT WOS:A1996UW83600024 ER PT J AU Cui, ST Gupta, SA Cummings, PT Cochran, HD AF Cui, ST Gupta, SA Cummings, PT Cochran, HD TI Molecular dynamics simulations of the rheology of normal decane, hexadecane, and tetracosane SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NORMAL-BUTANE; ALKANES; FLUIDS AB Extensive nonequilibrium molecular dynamics simulations have been carried out for liquid decane, hexadecane, and tetracosane at densities corresponding to atmospheric pressure and near ambient temperatures. The strain-rate-dependent viscosity has been obtained for strain rates ranging over several orders of magnitude. At high strain rate, the viscosities for all alkanes studied here have similar values and exhibit similar power-law shear-thinning behavior with a slope between about -0.40 and -0.33. Accompanying this shear thinning is the onset of orientational order and the alignment of the alkane molecules with the flow direction. The alignment angle tends to 45 degrees at very low strain rate and is significantly smaller at high strain rate, This suggests that the chains substantially align in the flow direction and that the dominant motion at high strain rate is the sliding of the chains parallel to the flow. At low strain rate, the shear viscosity shows a transition to Newtonian behavior. The Newtonian viscosity can be obtained from the plateau value of the shear viscosity at the lowest strain rates calculated from the nonequilibrium molecular dynamics simulation (NEMD). This is demonstrated by comparing the viscosity of decane obtained by extrapolating the NEMD simulation with an independent calculation using the standard Green-Kubo method. The transition from the non-Newtonian regime to the Newtonian regime is also correlated with the disappearance of orientational order and with the longest relaxation time of the liquid alkanes simulated. (C) 1996 American Institute of Physics. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RP Cui, ST (reprint author), UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996, USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 24 TC 96 Z9 97 U1 3 U2 19 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 15 PY 1996 VL 105 IS 3 BP 1214 EP 1220 DI 10.1063/1.471971 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UW836 UT WOS:A1996UW83600036 ER PT J AU Stirniman, MJ Huang, C Smith, RS Joyce, SA Kay, BD AF Stirniman, MJ Huang, C Smith, RS Joyce, SA Kay, BD TI The adsorption and desorption of water on single crystal MgO(100): The role of surface defects SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ACID-BASE PROPERTIES; MGO SURFACES; OXIDES; FILMS; H2O AB Adsorption and desorption of water on well-ordered and sputter-damaged single crystal MgO(100) surfaces were studied by a combination of molecular beam reflection and temperature programmed desorption techniques. Adsorption exhibits precursor-mediated kinetics and desorption exhibits a strong dependence on substrate treatment, demonstrating the importance of surface defects. (C) 1996 American Institute of Physics. C1 PACIFIC NW NATL LAB,ENVIRONM MOLEC SCI LAB,RICHLAND,WA 99352. RI Smith, Scott/G-2310-2015; Joyce, Stephen/Q-7804-2016 OI Smith, Scott/0000-0002-7145-1963; Joyce, Stephen/0000-0003-1330-7362 NR 26 TC 123 Z9 123 U1 3 U2 26 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 15 PY 1996 VL 105 IS 3 BP 1295 EP 1298 DI 10.1063/1.471993 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UW836 UT WOS:A1996UW83600043 ER PT J AU Meza, JC Judson, RS Faulkner, TR Treasurywala, AM AF Meza, JC Judson, RS Faulkner, TR Treasurywala, AM TI A comparison of a direct search method and a genetic algorithm for conformational searching SO JOURNAL OF COMPUTATIONAL CHEMISTRY LA English DT Article ID SMALL MOLECULES AB We present results from the application of two conformational searching methods: genetic algorithms (GA) and direct search methods for finding low energy conformations of organic molecules. GAs are in a class of biologically motivated optimization methods that evolve a population of individuals in which individuals who are more ''fit'' have a higher probability of surviving into subsequent generations. The parallel direct search method (PDS) it a type of pattern search method that uses an adaptive grid to search for minima. Both methods found energies equal to or lower than the energy of the relaxed crystal structure in all cases, at a relatively small cost in CPU time. We suggest that either method would be a good candidate to find 3-D conformations in a large scale screening application. (C) 1996 by John Wiley & Sons, Inc. C1 SANDIA NATL LABS,DISTRIBUTED SYST RES,LIVERMORE,CA 94551. ALLELIX BIOPHARMACEUT,MISSISSAUGA,ON L4V 1P1,CANADA. RP Meza, JC (reprint author), SANDIA NATL LABS,DEPT COMP SCI,MS 9214,LIVERMORE,CA 94551, USA. RI Meza, Juan/B-5601-2012; OI Meza, Juan/0000-0003-4543-0349; Judson, Richard/0000-0002-2348-9633 NR 33 TC 37 Z9 37 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0192-8651 J9 J COMPUT CHEM JI J. Comput. Chem. PD JUL 15 PY 1996 VL 17 IS 9 BP 1142 EP 1151 DI 10.1002/(SICI)1096-987X(19960715)17:9<1142::AID-JCC6>3.0.CO;2-S PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA UQ320 UT WOS:A1996UQ32000006 ER PT J AU Yi, JC Canright, GS Sandler, IM AF Yi, JC Canright, GS Sandler, IM TI A study of the ANNNI model using a dissipative map SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID FRENKEL-KONTOROVA MODEL; MEAN-FIELD THEORY; DEVILS STAIRCASE; ISING-MODEL; COMMENSURATE PHASES; SURFACE SEGREGATION; TWIST MAP; ALLOYS AB It is well known that extrema of classical, one-dimensional systems can be viewed as trajectories of a nonlinear, volume-preserving map. However, in general, thermodynamically stable extrema (i.e., local minima) of the free energy are numerically unstable trajectories of the map and so difficult to study by this technique. Here we explore a recent idea involving the use of a dissipative map to study the same kind of problem. Such a map may be designed so that its attractors are equal to, or close to, local minima of the energy. We apply such a dissipative map to the mean-field ANNNI model. We find that the technique reliably locates many kinds of metastable state: ferromagnetic, paramagnetic, commensurate, and incommensurate. However, the map also has two notable failings: it (apparently) has no chaotic attractors; and it fails to find correctly metastable states in a region of the phase diagram which is dominated by incommensurate states. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Yi, JC (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 26 TC 1 Z9 1 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUL 15 PY 1996 VL 8 IS 29 BP 5325 EP 5344 DI 10.1088/0953-8984/8/29/009 PG 20 WC Physics, Condensed Matter SC Physics GA UY174 UT WOS:A1996UY17400009 ER PT J AU Cooper, DI Eichinger, WE Barr, S Cottingame, W Hynes, MV Keller, CF Lebeda, CF Poling, DA AF Cooper, DI Eichinger, WE Barr, S Cottingame, W Hynes, MV Keller, CF Lebeda, CF Poling, DA TI High-resolution properties of the equatorial Pacific marine atmospheric boundary layer from lidar and radiosonde observations SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SEA-SURFACE TEMPERATURE; AIRCRAFT OBSERVATIONS; TURBULENCE STRUCTURE; ENTRAINMENT ZONE; DEEP CONVECTION; MIXED-LAYER; WATER-VAPOR; SOLAR-BLIND; RAMAN LIDAR; OCEAN AB A ''thermostat'' mechanism for cooling the Equatorial Pacific is being tested with data collected during the Central Equatorial Pacific Experiment. The Los Alamos National Laboratory participated by fielding two shipboard lidars that collected nearly continuous data over the Pacific from 10 to 21 March 1993 as the ship sailed from Guadalcanal to Christmas Island. A Raman lidar measured water vapor mixing ratio in the lower troposphere, especially in the marine atmospheric boundary layer (ABL), and an aerosol backscatter lidar measured height and thickness of clouds to an altitude of 20 km. The data collected from these two lidars were used to determine ocean-atmosphere phenomenology, which in turn, affects the climatology of the Central Pacific. Agreement between coincident radiosonde and the Raman water vapor lidar measurements was typically within +/-0.25 g kg(-1) of water. Divergence between the two instruments occurred at transitions between distinct layers in the lower marine atmosphere. Reasons for this divergence will be discussed. Above the ABL the lidar and radiosonde are in excellent agreement. A wealth of detail is apparent in the lidar-derived profiles. For example, there are large variations in water vapor mixing ratio-the expression of the inherent low-frequency, intermittent, atmospheric turbulence that produces spatially discrete features such as convective plumes. These features define the structure and extent of the ABL. Using the ABL structural characteristics, an analysis of the relationship between entrainment zone (EZ) height and observed sea surface temperature (SST) revealed counterintuitive behavior-that the height of the EZ decreases as SST increases in the range between 27 degrees and 30 degrees C. RP Cooper, DI (reprint author), LOS ALAMOS NATL LAB,EES-5,MS C300,LA-UR-94-101,LOS ALAMOS,NM 87545, USA. NR 56 TC 24 Z9 24 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD JUL 15 PY 1996 VL 53 IS 14 BP 2054 EP 2075 DI 10.1175/1520-0469(1996)053<2054:HRPOTE>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UZ736 UT WOS:A1996UZ73600008 ER PT J AU Raj, R AF Raj, R TI A mechanistic basis for high strain rate superplasticity of aluminum based metal matrix composites SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE aluminium; superplasticity; strain rates ID DIFFUSIONAL CREEP; DUCTILITY; FLOW; AL AB Aluminum based metal matrix composites exhibit superplasticity at unusually fast strain rates (0.01 to 100 s(-1)). An analysis of these data suggests the presence of a superplastic anomaly, characterized by high values of the strain rate sensitivity, and by flow stresses that depend on the grain size, even though the nominal deformation mechanism lies in the power law creep regime. The anomaly is explained in terms of stochastic events of rapid grain boundary sliding. These events are nucleated by stress-induced grain boundary migration which, by reducing the amplitude of the boundary shape, accelerate the rate of diffusion-accommodated sliding. An equation for the strain rate where such supercritical sliding events are expected is derived. This equation has the same form as the classical equation for diffusional creep except that it is multiplied by an acceleration factor of magnitude 80-380. In this way relationships between stress, strain rate, temperature, and grain size that quantitatively describe the onset of the anomaly are obtained. RP Raj, R (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,MS-K765,LOS ALAMOS,NM 87545, USA. NR 24 TC 4 Z9 4 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 15 PY 1996 VL 212 IS 1 BP 14 EP 21 DI 10.1016/0921-5093(96)10203-3 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UY796 UT WOS:A1996UY79600003 ER PT J AU Hsueh, CH Becher, PF AF Hsueh, CH Becher, PF TI Residual thermal stresses in ceramic composites .1. With ellipsoidal inclusions SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE residual thermal stresses; ceramic composites; mechanical properties ID SILICON-NITRIDE; OXYNITRIDE; BEHAVIOR; MATRIX AB Residual thermal stresses in ceramic matrix composites containing ellipsoidal inclusions are analyzed using a modified Eshelby mode. Closed-form analytical solutions are obtained; however, their formulations are formidable. When the inclusion is disc-shaped, spherical, or fiber-shaped, single analytical solutions can be obtained using different models, and they are in excellent agreement with those obtained from the modified Eshelby model. The analytical solutions are compared with the experimental and finite element results. Also, effects of the aspect ratio and the volume fraction of inclusions on residual thermal stresses are examined. RP Hsueh, CH (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. RI Hsueh, Chun-Hway/G-1345-2011 NR 18 TC 28 Z9 29 U1 1 U2 9 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 15 PY 1996 VL 212 IS 1 BP 22 EP 28 DI 10.1016/0921-5093(96)10176-3 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UY796 UT WOS:A1996UY79600004 ER PT J AU Hsueh, CH Becher, PF AF Hsueh, CH Becher, PF TI Residual thermal stresses in ceramic composites .2. With short fibers SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE residual thermal stresses; ceramic composites ID PULL-OUT STRESSES; REINFORCED COMPOSITES; INTERFACES; TESTS AB The residual thermal stresses in ceramic composites containing short fibers (i.e., fibers of finite length) are analyzed. Whereas the residual stresses in an embedded ellipsoidal inclusion are uniform, the residual stresses in an embedded short fiber are non-uniform. These non-uniform stresses in the fiber are analyzed using a shear lag model. To satisfy the continuity condition at the fiber ends, a technique of assuming imaginary fibers in the composite is adopted in the present study. The predicted residual axial strain along the fiber length is compared with the experimental measurements. Effects of (1) the distance between the fiber end and the free surface of the composite and (2) the aspect ratio of the fiber on the residual stresses are examined. RP Hsueh, CH (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. RI Hsueh, Chun-Hway/G-1345-2011 NR 14 TC 12 Z9 12 U1 1 U2 10 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 15 PY 1996 VL 212 IS 1 BP 29 EP 35 DI 10.1016/0921-5093(96)10177-5 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UY796 UT WOS:A1996UY79600005 ER PT J AU Song, SG Chen, CL Tsong, TT AF Song, SG Chen, CL Tsong, TT TI Field ion microscopy observation of intrinsic stacking faults in iridium SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE iridium; field ion microscopy; intrinsic stacking fault AB An intrinsic stacking fault in Ir is characterized using FIM techniques. Lattice distortion in the vicinity of the partial dislocation loop bounding the fault is evaluated. The maximum radius of visible distortion in the vicinity of the partial dislocation is found to be - 4.6 nm. This result provides experimental data for the assessment of the magnitude of lattice disturbance caused by crystal defects, which can be useful in the computer modeling of crystal defects. C1 ACAD SINICA,INST PHYS,TAIPEI 11529,TAIWAN. RP Song, SG (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 7 TC 2 Z9 2 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 15 PY 1996 VL 212 IS 1 BP 119 EP 122 DI 10.1016/0921-5093(96)10175-1 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UY796 UT WOS:A1996UY79600016 ER PT J AU Sulzer, B Perelson, AS AF Sulzer, B Perelson, AS TI Equilibrium binding of multivalent ligands to cells: Effects of cell and receptor density SO MATHEMATICAL BIOSCIENCES LA English DT Article ID FC-GAMMA RECEPTORS; CROSS-LINKING; MONOCLONAL-ANTIBODY; HISTAMINE-RELEASE; IMMUNOGLOBULIN-E; LYMPHOCYTES-B; ACTIVATION; ANTIGEN; SURFACE; IMMUNOGENICITY AB We study the equilibrium binding properties of multivalent ligands to cell surface receptors. We examine the effects of cell density and number of receptors per cell, that is, receptor concentration, on ligand binding. These parameters can significantly affect the formation of receptor aggregates and cross-links. We then use our general results to show that ligand-induced cell proliferation may be self-limiting, since ligand depletion reduces the signal received by individual cells once the cell population has expanded. We discuss the concept of avidity and show its limitations. As a specific example, we examine the binding of haptenated polymers to B cells and reinterpret experiments related to the immunon theory of B-cell activation. RP Sulzer, B (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. FU NCRR NIH HHS [RR06555]; PHS HHS [A128433] NR 37 TC 24 Z9 24 U1 0 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0025-5564 J9 MATH BIOSCI JI Math. Biosci. PD JUL 15 PY 1996 VL 135 IS 2 BP 147 EP 185 DI 10.1016/0025-5564(96)00022-3 PG 39 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA UW168 UT WOS:A1996UW16800003 PM 8768219 ER PT J AU Rodriguez, G Taylor, AJ AF Rodriguez, G Taylor, AJ TI Screening of the bias field in terahertz generation from photoconductors SO OPTICS LETTERS LA English DT Article ID ELECTROMAGNETIC PULSES; RADIATION; TRANSPORT; DYNAMICS; CARRIER AB We include screening of the bias field by the space charge induced by carrier transport and by the generated terahertz radiation in a model describing the far-field electromagnetic radiation from a large-aperture biased photoconductor triggered by an ultrashort optical pulse. At high fluences, space-charge screening is shown to produce bipolar terahertz waveforms. However, the dominant saturation mechanism is screening of the bias field by the radiated terahertz field. (C) 1996 Optical Society of America RP Rodriguez, G (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 10 TC 48 Z9 50 U1 0 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUL 15 PY 1996 VL 21 IS 14 BP 1046 EP 1048 DI 10.1364/OL.21.001046 PG 3 WC Optics SC Optics GA UW232 UT WOS:A1996UW23200013 PM 19876247 ER PT J AU Theiler, J Prichard, D AF Theiler, J Prichard, D TI Constrained-realization Monte-Carlo method for hypothesis testing SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article ID CHAOTIC TIME-SERIES; LYAPUNOV EXPONENTS; ESTIMATING DIMENSION; SURROGATE DATA; ATTRACTORS; DETERMINISM; SIMULATION; DYNAMICS; SPECTRUM; MODEL AB We compare two theoretically distinct approaches to generate artificial (or ''surrogate'') data for testing hypotheses about a given data set. The first and more straightforward approach is to fit a single ''best'' model to the original data, and then to generate surrogate data sets that are ''typical realizations'' of that model. The second approach concentrates not on the model but directly on the original data; it attempts to constrain the surrogate data sets so that they exactly agree with the original data for a specified set of sample statistics, Examples of these two approaches are provided for two simple cases; a test for deviations from a gaussian distribution, and a test for serial dependence in a time series. Additionally, we consider tests for nonlinearity in time series based on a Fourier transform (FT) method and on more conventional autoregressive moving-average (ARMA) fits to the data. The comparative performance of hypothesis testing schemes based on these two approaches is found to depend on whether or not the discriminating statistic is pivotal. A statistic is ''pivotal'' if its distribution is the same for all processes consistent with the null hypothesis. The typical-realization method requires that the discriminating statistic satisfy this property. The constrained-realization approach, on the other hand, does not share this requirement, and can provide an accurate and powerful test without having to sacrifice flexibility in the choice of discriminating statistic. C1 SANTA FE INST, SANTA FE, NM 87501 USA. UNIV ALASKA, DEPT PHYS, FAIRBANKS, AK 99775 USA. LOS ALAMOS NATL LAB, DIV THEORET, COMPLEX SYST GRP, LOS ALAMOS, NM 87545 USA. RP Theiler, J (reprint author), LOS ALAMOS NATL LAB, ASTROPHYS & RADIAT MEASUREMENTS GRP, LOS ALAMOS, NM 87545 USA. NR 60 TC 145 Z9 153 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD JUL 15 PY 1996 VL 94 IS 4 BP 221 EP 235 DI 10.1016/0167-2789(96)00050-4 PG 15 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA UW990 UT WOS:A1996UW99000005 ER PT J AU Delin, A Eriksson, O Ahuja, R Johansson, B Brooks, MSS Gasche, T Auluck, S Wills, JM AF Delin, A Eriksson, O Ahuja, R Johansson, B Brooks, MSS Gasche, T Auluck, S Wills, JM TI Optical properties of the group-IVB refractory metal compounds SO PHYSICAL REVIEW B LA English DT Article ID ZIRCONIUM NITRIDE FILMS; DIELECTRIC FUNCTION; BRILLOUIN-ZONE; SPECIAL POINTS; TIN; BAND; ZRN; CONSTANTS; TITANIUM; SYSTEMS AB We have calculated ab initio the direct interband electric dipole transitions of the carbides, nitrides, and oxides of Ti, Zr, and Hf in the rocksalt structure using the full-potential linear muffin-tin orbital method. The dipole matrix elements are calculated explicitly. Our results are in extraordinarily good agreement with experiment. The optical spectra are analyzed and we explain the origin of the different structures in the spectra in terms of the calculated electronic structure. We also discuss the trends in the optical properties as the metal and nonmetal atom types are changed and how these trends relate to general concepts such as band filling, nuclear charge, and bandwidth. C1 COMMISS EUROPEAN COMMUNITIES,EUROPEAN INST TRANSURANIUM ELEMENTS,D-76125 KARLSRUHE,GERMANY. UNIV AVEIRO,DEPT FIS,P-3800 AVEIRO,PORTUGAL. UNIV ROORKEE,DEPT PHYS,ROORKEE 247667,UTTAR PRADESH,INDIA. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Delin, A (reprint author), UNIV UPPSALA,DEPT PHYS,CONDENSED MATTER THEORY GRP,S-75121 UPPSALA,SWEDEN. RI Universidade Aveiro, Departamento Fisica/E-4128-2013; Eriksson, Olle/E-3265-2014; Delin, Anna/P-2100-2014; OI Eriksson, Olle/0000-0001-5111-1374; Delin, Anna/0000-0001-7788-6127; gasche, thomas/0000-0002-3317-7959 NR 37 TC 79 Z9 79 U1 2 U2 22 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1996 VL 54 IS 3 BP 1673 EP 1681 DI 10.1103/PhysRevB.54.1673 PG 9 WC Physics, Condensed Matter SC Physics GA UZ861 UT WOS:A1996UZ86100050 ER PT J AU Shan, YY AsokaKumar, P Lynn, KG Fung, S Beling, CD AF Shan, YY AsokaKumar, P Lynn, KG Fung, S Beling, CD TI Field effect on positron diffusion in semi-insulating GaAs SO PHYSICAL REVIEW B LA English DT Article ID MONTE-CARLO CALCULATIONS; MONOENERGETIC POSITRONS; TEMPERATURE-DEPENDENCE; KEV ELECTRON; SURFACES; MOBILITY; SI; INTERFACE; SOLIDS; ANNIHILATION AB An energy-tunable monoenergetic positron beam was used to study positron diffusion in the space-charge region of an Au/GaAs(SI) (semi-insulating) Schottky contact, where the electric field reaches similar to 10(5) V cm(-1) by reverse biasing the diode. An analytical solution of the time-dependent positron drift-diffusion model under an electric field was obtained for the case of a semi-infinite body with a capturing boundary, and explains the experimental results well. A positron diffusion coefficient of 1.8+/-0.2 cm(-2) s(-1), and a positron mobility of 70+/-10 cm(2) V-1 s(-1) in GaAs(SI) at 300 K, were obtained independently. This result is consistent with the Einstein relation. The dependence of the positron current density at the Au/GaAs interface on the electric field shows that GaAs(SI) is a possible candidate for the fabrication of the field-assisted positron moderator. C1 UNIV HONG KONG,DEPT PHYS,HONG KONG,HONG KONG. RP Shan, YY (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11793, USA. NR 39 TC 16 Z9 16 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1996 VL 54 IS 3 BP 1982 EP 1986 DI 10.1103/PhysRevB.54.1982 PG 5 WC Physics, Condensed Matter SC Physics GA UZ861 UT WOS:A1996UZ86100087 ER PT J AU Varekamp, PR Hakansson, MC Kanski, J Shuh, DK Bjorkqvist, M Gothelid, M Simpson, WC Karlsson, UO Yarmoff, JA AF Varekamp, PR Hakansson, MC Kanski, J Shuh, DK Bjorkqvist, M Gothelid, M Simpson, WC Karlsson, UO Yarmoff, JA TI Reaction of I-2 with the (001) surfaces of GaAs, InAs, and InSb .1. Chemical interaction with the substrate SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; CORE-LEVEL PHOTOEMISSION; CLEAVED GAAS(110) SURFACES; GALLIUM-ARSENIDE; IODINE; ADSORPTION; RECONSTRUCTIONS; TEMPERATURE; CHLORINE; CHEMISORPTION AB InAs(001)-c(8x2), InSb(001)-c(8x2), and several reconstructions of GaAs(001) are exposed at room temperature to iodine molecules (I-2). Low-energy electron diffraction (LEED) and synchrotron soft x-ray photoelectron spectroscopy (SXPS) are employed to study the surfaces as a function of I-2 dose and sample anneal. In the exposure range studied, GaAs and InAs become saturated with I-2, resulting in removal of the clean surface reconstruction and the formation of a very strong 1x1 LEED pattern. Iodine bonds primarily to the dominant elemental species present on the clean surface, whether it is a group-III or -V element. The InSb(001)-c(8x2) reconstruction is also removed by I-2 adsorption, and a strong 1x1 LEED pattern is formed. SXPS data, in conjunction with scanning tunneling microscopy images, however, reveal that InSb(001)-c(8x2) does not saturate at room temperature, but is instead etched with a preferential loss of In. Heating the iodine-covered group-III-rich InAs(001)-c(8x2) and InSb(001)-c(8x2) surfaces causes removal of the iodine overlayer and transformation to a group-V-rich reconstruction. When the iodine-covered As-rich GaAs(001)-c(2x8) surface is heated to remove iodine, however, the c(2x8) reconstruction is simply regenerated. C1 LUND UNIV,INST PHYS,DEPT SYNCHROTRON RADIAT RES,S-22362 LUND,SWEDEN. CHALMERS UNIV TECHNOL,DEPT PHYS,S-41296 GOTHENBURG,SWEDEN. UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Varekamp, PR (reprint author), ROYAL INST TECHNOL,DEPT PHYS,S-10044 STOCKHOLM,SWEDEN. NR 48 TC 34 Z9 35 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1996 VL 54 IS 3 BP 2101 EP 2113 DI 10.1103/PhysRevB.54.2101 PG 13 WC Physics, Condensed Matter SC Physics GA UZ861 UT WOS:A1996UZ86100100 ER PT J AU Varekamp, PR Hakansson, MC Kanski, J Bjorkqvist, M Gothelid, M Kowalski, BJ He, ZQ Shuh, DK Yarmoff, JA Karlsson, UO AF Varekamp, PR Hakansson, MC Kanski, J Bjorkqvist, M Gothelid, M Kowalski, BJ He, ZQ Shuh, DK Yarmoff, JA Karlsson, UO TI Reaction of I-2 with the (001) surfaces of GaAs, InAs, and InSb .2. Ordering of the iodine overlayer SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; CORE-LEVEL PHOTOEMISSION; MOLECULAR HALOGENS; ADSORPTION; GAAS(110); RECONSTRUCTIONS; INSB(100); CHLORINE; BR-2; TEMPERATURE AB The overlayer formed by the reaction of molecular iodine (I-2) with GaAs(001), InAs(001), and InSb(001) is investigated with synchrotron soft x-ray photoelectron spectroscopy (SXPS) and scanning tunneling microscopy (STM). Two components, separated by about 0.5 eV, are present in all of the I 4d SXPS spectra. At very low iodine coverages, the high binding energy (BE) component dominates. When the iodine coverage saturates, however, the two components have equal intensities. In contrast to GaAs and InAs, exposure of InSb(001)-c(8x2) to additional I-2 results in a further increase of the relative intensity of the low-BE component. STM images of I-2 covered InSb(001)-c(8x2) directly reveal the ordering in the overlayer. Islands are visible for submonolayer coverages, suggesting that adsorption occurs via a mobile precursor state. STM images feature occupies a 1x1 unit cell with the same spacing as bulk-terminated InSb(001). The other feature has a coverage of similar to 1/3 ML and is arranged in pairs oriented along the [110] azimuth. C1 LUND UNIV,INST PHYS,DEPT SYNCHROTRON RADIAT RES,S-22362 LUND,SWEDEN. CHALMERS UNIV TECHNOL,DEPT PHYS,S-41296 GOTHENBURG,SWEDEN. POLISH ACAD SCI,INST PHYS,PL-02668 WARSAW,POLAND. UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Varekamp, PR (reprint author), ROYAL INST TECHNOL,DEPT PHYS MAT PHYS,S-10044 STOCKHOLM,SWEDEN. RI Kowalski, Bogdan/A-2259-2015 OI Kowalski, Bogdan/0000-0003-4821-5265 NR 33 TC 11 Z9 12 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1996 VL 54 IS 3 BP 2114 EP 2120 DI 10.1103/PhysRevB.54.2114 PG 7 WC Physics, Condensed Matter SC Physics GA UZ861 UT WOS:A1996UZ86100101 ER PT J AU Liu, LZ Henrich, VE Ellis, WP Shindo, I AF Liu, LZ Henrich, VE Ellis, WP Shindo, I TI Bulk and surface electronic structure of Li2O SO PHYSICAL REVIEW B LA English DT Article ID LITHIUM-OXIDE; PHOTOEMISSION; MGO; SPECTRA; ENERGY; SPECTROSCOPY; TEMPERATURE; HYDROGEN; ABINITIO; LATTICE AB We have used photoemission and electron-energy-loss spectroscopies to determine the surface and bulk electronic structure of a single-crystal sample of the alkali-metal oxide Li2O. The predominately O 2p valence band exhibits two main features in the photoemission spectrum, whose relative widths are consistent with results of an ab initio Hartree-Fock calculation of the bulk electronic structure. However, changes in the intensity of the two features as a function of the exciting photon energy are large and not understood. Energy-loss spectra show the presence of a strong surface exciton in the bulk band gap of Li2O; such excitonic surface states do not exist for the alkali halides. Its energy is about 2 eV less than the bulk band gap, similar to the surface excitonic shifts that have been observed in the alkaline-earth oxides. C1 YALE UNIV,DEPT APPL PHYS,NEW HAVEN,CT 06520. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. ASGAL CO LTD,CHIBA 28912,JAPAN. NR 29 TC 49 Z9 49 U1 2 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1996 VL 54 IS 3 BP 2236 EP 2239 DI 10.1103/PhysRevB.54.2236 PG 4 WC Physics, Condensed Matter SC Physics GA UZ861 UT WOS:A1996UZ86100115 ER PT J AU Hjelm, A Granqvist, CG Wills, JM AF Hjelm, A Granqvist, CG Wills, JM TI Electronic structure and optical properties of WO3, LiWO3, NaWO3, and HWO3 SO PHYSICAL REVIEW B LA English DT Article ID TUNGSTEN TRIOXIDE FILMS; X-RAY-DIFFRACTION; BRILLOUIN-ZONE; SPECIAL POINTS; CRYSTALLINE; EXCHANGE; DENSITY; BAND; REFLECTANCE; MODULATION AB The electronic structures for cubic WO3, LiWO3, NaWO3, HWO3, H2WO3, and hexagonal WO3 have been calculated. The calculations rely on the local approximation to density functional theory and use a full-potential linear mufin-tin orbitals method. The incorporation of ions in tungsten oxide by chemical or electrochemical methods is the basis for several technological applications related to solid state ionics. Essentially, incorporation of alkali ions results in an s-band high above the Fermi level, and the charge-balancing electrons take part in a rigid band filling of the W d conduction band. Hydrogen forms a hydroxide unit with one oxygen atom, and we find a minimum in total energy for a bond length of 1.03 Angstrom. The cubic phase of WO3 can take up more than one hydrogen atom, and the formation of two hydroxide units is preferable to one water molecule. The calculated dielectric function and reflectance of LixWO3 and NaxWO3 are presented, and the change in optical properties being the basis for reflective electrochromism is reproduced, although the reflectance curves show some deviations from experiments. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87544. RP Hjelm, A (reprint author), UNIV UPPSALA,DEPT TECHNOL,BOX 534,S-75121 UPPSALA,SWEDEN. NR 48 TC 164 Z9 164 U1 13 U2 113 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1996 VL 54 IS 4 BP 2436 EP 2445 DI 10.1103/PhysRevB.54.2436 PG 10 WC Physics, Condensed Matter SC Physics GA VB249 UT WOS:A1996VB24900030 ER PT J AU Claessen, R Anderson, RO Gweon, GH Allen, JW Ellis, WP Janowitz, C Olson, CG Shen, ZX Eyert, V Skibowski, M Friemelt, K Bucher, E Hufner, S AF Claessen, R Anderson, RO Gweon, GH Allen, JW Ellis, WP Janowitz, C Olson, CG Shen, ZX Eyert, V Skibowski, M Friemelt, K Bucher, E Hufner, S TI Complete band-structure determination of the quasi-two-dimensional Fermi-liquid reference compound TiTe2 SO PHYSICAL REVIEW B LA English DT Article ID TRANSITION-METAL DICHALCOGENIDES; CHARGE-DENSITY WAVES; 2D HUBBARD-MODEL; PHOTOEMISSION; STATE; BEHAVIOR AB The electronic structure of the layered compound 1T-TiTe2 has been studied in detail by high-resolution angle-resolved photoelectron spectroscopy (ARPES) and density-functional band calculations. The results confirm the semimetallic nature of this material as due to an overlap of Te 5p- and Ti 3d-like conduction bands. We find an overall good correspondence between experiment and theory, with ail ARPES structures accounted for by the: calculated band structure. Particular focus is applied to the bands near the Fermi level and to the Fermi-surface topology. Interesting behavior is observed for an essentially Ti 3d(z)2-derived conduction band, whose measured Fermi vector and qualitative shape are excellently reproduced by the calculation. However, the experimental energy dispersion of the Ti 3d,2 ARPES peak appears to be considerably reduced with respect to band theory. From these results we obtain a picture of the electronic structure of 1T-TiTe2 as that of a Fermi liquid with renormalized quasiparticle dispersions and a Fermi surface in accordance with Luttinger's sumrule. We show that the experimental Ti 3 d(z)2 emission is quasi-two-dimensional near the Fermi surface, which, together with its being remarkably unobscured, virtually free of any interference with other spectral structures or inelastic background, makes it an ideal object for ARPES line-shape studies on a Fermi-liquid system. C1 UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109. UNIV CALIF LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES,IA 50011. STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305. MAX PLANCK INST FESTKORPERFORSCH,D-70569 STUTTGART,GERMANY. UNIV KIEL,INST EXPT PHYS,D-24118 KIEL,GERMANY. UNIV KONSTANZ,FAK PHYS,D-78434 CONSTANCE,GERMANY. RP Claessen, R (reprint author), UNIV SAARLANDES,FACHBEREICH EXPT PHYS,D-66041 SAARBRUCKEN,GERMANY. RI Eyert, Volker/C-5968-2008; Claessen, Ralph/A-2045-2017 OI Claessen, Ralph/0000-0003-3682-6325 NR 39 TC 55 Z9 55 U1 4 U2 35 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1996 VL 54 IS 4 BP 2453 EP 2465 DI 10.1103/PhysRevB.54.2453 PG 13 WC Physics, Condensed Matter SC Physics GA VB249 UT WOS:A1996VB24900032 ER PT J AU Alouani, M Wills, JM AF Alouani, M Wills, JM TI Calculated optical properties of Si,Ge, and GaAs under hydrostatic pressure SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; DIELECTRIC-CONSTANT; REFRACTIVE-INDEX; BAND-STRUCTURE; SEMICONDUCTORS; SILICON; GE; SPECTRUM; SI; GERMANIUM AB The macroscopic dielectric function in the random-phase approximation without local-field effect has been implemented using the local-density approximation with an all-electron, full-potential linear muffin-tin orbital basis set. This method is used to investigate the optical properties of the semiconductors Si, Ge, and GaAs under hydrostatic pressure. The pressure dependence of the effective dielectric function is compared with the experimental data of Goni, Syassen, and Cardona [Phys. Rev. B 41, 10 104 (1990)], and excellent agreement is found when the so-called ''scissors-operator'' shift is used to account for the correct band gap at Gamma. The effect of the 3d semicore states in the interband transitions hardly changes the static dielectric function epsilon(infinity); however, their contribution to the intensity of absorption for higher photon energies is substantial. The spinorbit coupling has a significant effect on epsilon(infinity) of Ge and GaAs, but not of Si. The E(l) peak in the dynamical dielectric function is strongly underestimated for Si, but only slightly for Ge and GaAs, suggesting that excitonic effects might be important only for Si. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Alouani, M (reprint author), OHIO STATE UNIV,DEPT PHYS,174 W 18TH AVE,COLUMBUS,OH 43210, USA. RI Alouani, Mebarek/A-9101-2011 OI Alouani, Mebarek/0000-0002-7985-5276 NR 45 TC 68 Z9 68 U1 1 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1996 VL 54 IS 4 BP 2480 EP 2490 DI 10.1103/PhysRevB.54.2480 PG 11 WC Physics, Condensed Matter SC Physics GA VB249 UT WOS:A1996VB24900035 ER PT J AU Chico, L Benedict, LX Louie, SG Cohen, ML AF Chico, L Benedict, LX Louie, SG Cohen, ML TI Quantum conductance of carbon nanotubes with defects SO PHYSICAL REVIEW B LA English DT Article ID ELECTRICAL-RESISTANCE; ELECTRONIC-PROPERTIES; MICROTUBULES; TUBULES AB We study the conductance of metallic carbon nanotubes with vacancies and pentagon-heptagon pair defects within the Landauer formalism. Using a tight-binding model and a Green's function technique to calculate the scattering matrix, we examine the one-dimensional to two-dimensional crossover in these systems and show the existence of metallic tube junctions in which the conductance is suppressed for symmetry reasons. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RI Chico, Leonor/H-6395-2015 OI Chico, Leonor/0000-0002-7131-1266 NR 22 TC 392 Z9 398 U1 4 U2 32 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 1996 VL 54 IS 4 BP 2600 EP 2606 DI 10.1103/PhysRevB.54.2600 PG 7 WC Physics, Condensed Matter SC Physics GA VB249 UT WOS:A1996VB24900049 ER PT J AU Wilson, JR Mathews, GJ Marronetti, P AF Wilson, JR Mathews, GJ Marronetti, P TI Relativistic numerical model for close neutron-star binaries SO PHYSICAL REVIEW D LA English DT Article ID GRAVITATIONAL-RADIATION; COMPACT OBJECTS; (POST)5/2-NEWTONIAN ORDER; R-PROCESS; SIMULATIONS; SYSTEMS; COLLISIONS; EVOLUTION; PULSAR; COINCIDENCE AB We describe a numerical method for calculating the (3+1)-dimensional general relativistic hydrodynamics of a coalescing neutron-star binary system. The relativistic field equations are solved at each time slice with a spatial three-metric chosen to be conformally flat. Against this solution to the general relativistic field equations, the hydrodynamic variables and gravitational radiation are allowed to respond. The gravitational radiation signal is derived via a multipole expansion of the metric perturbation to the hexadecapole (l=4) order including both mass and current moments and a correction for the slow-motion approximation. Using this expansion, the effect of gravitational radiation on the system evolution can also be recovered by introducing an acceleration term in the matter evolution. In the present work we illustrate the method by applying this model to evaluate various orbits of two neutron stars with a gravitational mass of 1.45M(.) near the time of the final merger. We discuss the evidence that, for a realistic neutron-star equation of state, general relativistic effects may cause the stars to individually collapse into black holes prior to merging. Also, the strong fields cause the last stable orbit to occur at a larger separation distance and lower frequency than previously estimated. C1 UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556. RP Wilson, JR (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 57 TC 191 Z9 191 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 JUL 15 PY 1996 VL 54 IS 2 BP 1317 EP 1331 DI 10.1103/PhysRevD.54.1317 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA UY733 UT WOS:A1996UY73300011 ER PT J AU Grasso, D Kolb, EW AF Grasso, D Kolb, EW TI Cosmological bounds to the magnetic moment of heavy tau neutrinos SO PHYSICAL REVIEW D LA English DT Article ID PRIMORDIAL NUCLEOSYNTHESIS; UPPER LIMIT; DARK-MATTER; MASS; PLASMA; DECAYS AB The magnetic moment of tau neutrinos in the MeV mass range may he large enough to modify the cosmological freeze-out calculation and determine the tau-neutrino relic density. In this paper we reexamine such a possibility, We calculate the evolution and freeze-our of the tau-neutrino number density as a function of its mass and magnetic moment. We then determine its relic density; then calculate its effect upon primordial nucleo-synthesis including previously neglected effects. C1 UNIV STOCKHOLM,DEPT PHYS,S-11346 STOCKHOLM,SWEDEN. FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP Grasso, D (reprint author), UNIV UPPSALA,DEPT THEORET PHYS,BOX 803,S-75108 UPPSALA,SWEDEN. RI Grasso, Dario/I-2440-2012 OI Grasso, Dario/0000-0001-7761-7242 NR 29 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUL 15 PY 1996 VL 54 IS 2 BP 1374 EP 1378 DI 10.1103/PhysRevD.54.1374 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA UY733 UT WOS:A1996UY73300016 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J AnwayWiese, C Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Auchincloss, P Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J deBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Canz, D Cen, Y Cervelli, F Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Cunningham, JD Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demortier, L Denby, B Deninno, M Derwent, PF Devlin, T Dickson, M Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Frish, H Fuess, TA Fukui, Y Funaki, S Gagliardi, G Galeotti, S Gallinaro, M GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Juston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuns, E Laasanen, AT Labanca, N Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliver, R Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Park, S Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Scarpine, V Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Sgolacchia, A Shapiro, MD Shaw, NM Shen, Q Shephard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P SIngh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Tonnison, J deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wang, C Wang, CH Wang, G Wang, J Wang, MJ Wang, QF Warburton, A Watts, G Watts, T Webb, R Wei, C Wendt, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Wolinski, D Wolinski, J Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, YC Zanetti, A Zetti, F Zhang, L Zhang, W Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J AnwayWiese, C Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Auchincloss, P Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J deBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Canz, D Cen, Y Cervelli, F Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Cunningham, JD Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demortier, L Denby, B Deninno, M Derwent, PF Devlin, T Dickson, M Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Frish, H Fuess, TA Fukui, Y Funaki, S Gagliardi, G Galeotti, S Gallinaro, M GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Juston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuns, E Laasanen, AT Labanca, N Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliver, R Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Park, S Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Scarpine, V Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Sgolacchia, A Shapiro, MD Shaw, NM Shen, Q Shephard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P SIngh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Tonnison, J deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wang, C Wang, CH Wang, G Wang, J Wang, MJ Wang, QF Warburton, A Watts, G Watts, T Webb, R Wei, C Wendt, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Wolinski, D Wolinski, J Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, YC Zanetti, A Zetti, F Zhang, L Zhang, W Zucchelli, S TI Inclusive jet cross section in (p)over-bar-p collisions at root s=1.8TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID PBARP COLLISIONS; PARTON DISTRIBUTIONS; QUARK; TEV AB The inclusive jet differential cross section has been measured for jet transverse energies, ET, from 15 to 440 GeV, in the pseudorapidity region 0.1 less than or equal to \eta\ less than or equal to 0.7. The results are based on 19.5 pb(-1) of data collected by the CDF Collaboration at the Fermilab Tevatron collider. The data are compared with QCD predictions for various sets of parton distribution functions. The cross section for jets with E(T) > 200 GeV is significantly higher than current predictions based on O(alpha(s)(3)) perturbative QCD calculations. Various possible explanations for the high-E(T) excess are discussed. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV BOLOGNA,IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. BRANDEIS UNIV,WALTHAM,MA 02254. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV CHICAGO,CHICAGO,IL 60637. DUKE UNIV,DURHAM,NC 27708. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. HARVARD UNIV,CAMBRIDGE,MA 02138. HIROSHIMA UNIV,HIGASHIHIROSHIMA 724,JAPAN. UNIV ILLINOIS,URBANA,IL 61801. MCGILL UNIV,INST PARTICLE PHYS,MONTREAL,PQ H3A 2T8,CANADA. UNIV TORONTO,TORONTO,ON M5S 1A7,CANADA. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. MIT,CAMBRIDGE,MA 02139. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. OSAKA CITY UNIV,OSAKA 588,JAPAN. UNIV PADUA,IST NAZL FIS NUCL,I-35131 PADUA,ITALY. UNIV PENN,PHILADELPHIA,PA 19104. UNIV PISA,IST NAZL FIS NUCL,I-56100 PISA,ITALY. SCUOLA NORMALE SUPER PISA,I-56100 PISA,ITALY. UNIV PITTSBURGH,PITTSBURGH,PA 15260. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. ROCKEFELLER UNIV,NEW YORK,NY 10021. RUTGERS STATE UNIV,PISCATAWAY,NJ 08854. ACAD SINICA,TAIPEI 11529,TAIWAN. TEXAS A&M UNIV,COLLEGE STN,TX 77843. TEXAS TECH UNIV,LUBBOCK,TX 79409. UNIV TSUKUBA,TSUKUBA,IBARAKI 305,JAPAN. TUFTS UNIV,MEDFORD,MA 02155. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06511. RP Abe, F (reprint author), NATL LAB HIGH ENERGY PHYS,KEK,TSUKUBA,IBARAKI 305,JAPAN. RI Vucinic, Dejan/C-2406-2008; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Kim, Soo-Bong/B-7061-2014; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015 OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580 NR 29 TC 204 Z9 205 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 15 PY 1996 VL 77 IS 3 BP 438 EP 443 DI 10.1103/PhysRevLett.77.438 PG 6 WC Physics, Multidisciplinary SC Physics GA UW791 UT WOS:A1996UW79100008 ER PT J AU Huston, J Kovacs, E Kuhlmann, S Lai, HL Owens, JF Soper, D Tung, WK AF Huston, J Kovacs, E Kuhlmann, S Lai, HL Owens, JF Soper, D Tung, WK TI Large transverse momentum jet production and the gluon distribution inside the proton SO PHYSICAL REVIEW LETTERS LA English DT Article ID CROSS-SECTION; COLLISIONS; PHOTONS AB The CDF experiment has reported an excess of high-p, jets compared to previous next-to-leading order QCD expectations. Before attributing this to new physics effects, we investigate whether these high-p(t) jets can be explained by a modified gluon distribution inside the proton. We find enough flexibility in a global QCD analysis including the CDF inclusive jet data to provide a (25 - 35)% increase in the jet cross sections at the highest p(t) of the experiment. Two possible sets of parton distributions are presented, and the effects of these on other existing data sets are presented. Further theoretical and experimental work needed to clarify unresolved issues is outlined. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. UNIV OREGON,EUGENE,OR 97403. RP Huston, J (reprint author), MICHIGAN STATE UNIV,E LANSING,MI 48824, USA. NR 20 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 15 PY 1996 VL 77 IS 3 BP 444 EP 447 DI 10.1103/PhysRevLett.77.444 PG 4 WC Physics, Multidisciplinary SC Physics GA UW791 UT WOS:A1996UW79100009 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J AnwayWiese, C Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J DeBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Cauz, D Cen, Y Cervelli, F Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Cunningham, JD Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demortier, L Denby, B Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Frisch, H Fuess, TA Fukui, Y Funaki, S Gagliardi, G Galeotti, S Gallinaro, M GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N GIromini, P Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Huston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT Labanca, N Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliver, R Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Park, S Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Scarpine, V Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Sgolacchia, A Shapiro, MD Shaw, NM Shen, Q Shepard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Tonnison, J DeTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, R Unal, G VandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wang, C Wang, CH Wang, G Wang, J Wang, MJ Wang, QF Warburton, A Watts, T Webb, R Wei, C Wendt, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Wolinski, D Wolinski, J Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, JC Zanetti, A Zetti, F Zhang, L Zhang, W Zou, B Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J AnwayWiese, C Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J DeBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Cauz, D Cen, Y Cervelli, F Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Cunningham, JD Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demortier, L Denby, B Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Frisch, H Fuess, TA Fukui, Y Funaki, S Gagliardi, G Galeotti, S Gallinaro, M GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N GIromini, P Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Huston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT Labanca, N Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliver, R Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Park, S Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Scarpine, V Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Sgolacchia, A Shapiro, MD Shaw, NM Shen, Q Shepard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Tonnison, J DeTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, R Unal, G VandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wang, C Wang, CH Wang, G Wang, J Wang, MJ Wang, QF Warburton, A Watts, T Webb, R Wei, C Wendt, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Wolinski, D Wolinski, J Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, JC Zanetti, A Zetti, F Zhang, L Zhang, W Zou, B Zucchelli, S TI Properties of jets in Z boson events from 1.8 TeV (p)over-bar-p collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID PBARP COLLISIONS; HADRON COLLIDERS; DETECTOR AB We present a study of events with Z bosons and hadronic jets produced in <(p)over bar p> collisions at a center-of-mass energy of 1.8 TeV. The data consist of 6708 Z --> e(+)e(-) decays from 106 pb(-1) of integrated luminosity collected using the CDF detector at the Fermilab Tevatron Collider. The Z + greater than or equal to n jet cross sections and jet production properties have been measured for n = 1 to 4. The data are compared to predictions of leading-order QCD matrix element calculations with added gluon radiation and simulated parton fragmentation. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV BOLOGNA,IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. BRANDEIS UNIV,WALTHAM,MA 02254. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV CHICAGO,CHICAGO,IL 60637. DUKE UNIV,DURHAM,NC 27708. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. HARVARD UNIV,CAMBRIDGE,MA 02138. HIROSHIMA UNIV,HIGASHIHIROSHIMA 724,JAPAN. UNIV ILLINOIS,URBANA,IL 61801. MCGILL UNIV,INST PARTICLE PHYS,MONTREAL,PQ H3A 2T8,CANADA. UNIV TORONTO,TORONTO,ON M5S 1A7,CANADA. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. MIT,CAMBRIDGE,MA 02139. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. OSAKA CITY UNIV,OSAKA 588,JAPAN. UNIV PADUA,IST NAZL FIS NUCL,I-35131 PADUA,ITALY. UNIV PENN,PHILADELPHIA,PA 19104. UNIV PISA,IST NAZL FIS NUCL,I-56100 PISA,ITALY. SCUOLA NORMALE SUPER PISA,I-56100 PISA,ITALY. UNIV PITTSBURGH,PITTSBURGH,PA 15260. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. ROCKEFELLER UNIV,NEW YORK,NY 10021. RUTGERS STATE UNIV,PISCATAWAY,NJ 08854. ACAD SINICA,TAIPEI 11529,TAIWAN. TEXAS A&M UNIV,COLLEGE STN,TX 77843. TEXAS TECH UNIV,LUBBOCK,TX 79409. UNIV TSUKUBA,TSUKUBA,IBARAKI 305,JAPAN. TUFTS UNIV,MEDFORD,MA 02155. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06511. RP Abe, F (reprint author), NATL LAB HIGH ENERGY PHYS,KEK,TSUKUBA,IBARAKI 305,JAPAN. RI Introzzi, Gianluca/K-2497-2015; Vucinic, Dejan/C-2406-2008; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Kim, Soo-Bong/B-7061-2014; Paulini, Manfred/N-7794-2014 OI Introzzi, Gianluca/0000-0002-1314-2580; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787 NR 14 TC 14 Z9 14 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 JUL 15 PY 1996 VL 77 IS 3 BP 448 EP 453 DI 10.1103/PhysRevLett.77.448 PG 6 WC Physics, Multidisciplinary SC Physics GA UW791 UT WOS:A1996UW79100010 ER PT J AU Batteas, JD Dunphy, JC Somorjai, GA Salmeron, M AF Batteas, JD Dunphy, JC Somorjai, GA Salmeron, M TI Coadsorbate induced reconstruction of a stepped Pt(111) surface by sulfur and CO: A novel surface restructuring mechanism observed by scanning tunneling microscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRYSTAL-SURFACES; ADSORPTION; PLATINUM; TRANSFORMATION; CHEMISORPTION; CARBON; LEED AB The chemisorption of sulfur and CO was found to have profound effects on the structure of a stepped platinum surface. By itself, sulfur chemisorbs, forming a p(2 x 2) ordered structure, and induces doubling of the terrace widths and step heights. Subsequent coadsorption of CO displaces the sulfur, compressing it to distances of root 3 times the Pt lattice spacing, and induces surface restructuring; New terraces form which contain exclusively CO and are separated by monatomic steps from the terraces containing the compressed sulfur overlayer. This coadsorbate induced restructuring phenomenon has strong implications in the mechanisms of surface catalyzed reactions. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. RI Batteas, James/D-4144-2015 OI Batteas, James/0000-0002-6244-5000 NR 23 TC 45 Z9 46 U1 1 U2 11 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 JUL 15 PY 1996 VL 77 IS 3 BP 534 EP 537 DI 10.1103/PhysRevLett.77.534 PG 4 WC Physics, Multidisciplinary SC Physics GA UW791 UT WOS:A1996UW79100031 ER PT J AU Butorin, SM Mancini, DC Guo, JH Wassdahl, N Nordgren, J Nakazawa, M Tanaka, S Uozumi, T Kotani, A Ma, Y Myano, KE Karlin, BA Shuh, DK AF Butorin, SM Mancini, DC Guo, JH Wassdahl, N Nordgren, J Nakazawa, M Tanaka, S Uozumi, T Kotani, A Ma, Y Myano, KE Karlin, BA Shuh, DK TI Resonant X-ray fluorescence spectroscopy of correlated systems: A probe of charge-transfer excitations SO PHYSICAL REVIEW LETTERS LA English DT Article ID HOPPING-MATRIX-ELEMENTS; ELECTRONIC-STRUCTURE; CONFIGURATION DEPENDENCE; PHOTOEMISSION SPECTRA; SYNCHROTRON RADIATION; CE COMPOUNDS; ABSORPTION; MODEL; OXIDES; STATES AB X-ray fluorescence spectroscopy with monochromatic photon excitation is presented as a tool for studies of charge-transfer excitations in correlated systems, using CeO2 and UO3 as examples. Ce 4f --> 3d and U 5f --> 3d x-ray fluorescence, with excitation near the 3d thresholds, probes states as eigenvalues for the groundstate Hamiltonian from the Anderson impurity model. Sweeping the excitation energy across 3d absorption edges enhances contributions of different electronic configurations to fluorescence so that observed resonances indicate the charge-transfer origin of the absorption satellites. C1 UNIV UPPSALA, DEPT PHYS, S-75121 UPPSALA, SWEDEN. UNIV TOKYO, INST SOLID STATE PHYS, MINATO KU, TOKYO 106, JAPAN. UNIV OSAKA PREFECTURE, COLL ENGN, SAKAI, OSAKA 593, JAPAN. UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. CUNY BROOKLYN COLL, DEPT PHYS, BROOKLYN, NY 11210 USA. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. NR 31 TC 108 Z9 109 U1 5 U2 31 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 JUL 15 PY 1996 VL 77 IS 3 BP 574 EP 577 DI 10.1103/PhysRevLett.77.574 PG 4 WC Physics, Multidisciplinary SC Physics GA UW791 UT WOS:A1996UW79100041 ER PT J AU Dogan, ON AF Dogan, ON TI Columnar to equiaxed transition in high Cr white iron castings SO SCRIPTA MATERIALIA LA English DT Article ID EUTECTIC CARBIDES RP Dogan, ON (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 11 TC 14 Z9 18 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUL 15 PY 1996 VL 35 IS 2 BP 163 EP 168 DI 10.1016/1359-6462(96)00110-8 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UQ579 UT WOS:A1996UQ57900005 ER PT J AU McKamey, CG Lee, EH Cohron, JW George, EP AF McKamey, CG Lee, EH Cohron, JW George, EP TI The effect of low-pressure oxygen exposure on the high-temperature tensile impact ductility of a thorium-doped iridium alloy SO SCRIPTA MATERIALIA LA English DT Article RP McKamey, CG (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI George, Easo/L-5434-2014 NR 12 TC 9 Z9 14 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUL 15 PY 1996 VL 35 IS 2 BP 181 EP 185 DI 10.1016/1359-6462(96)00119-4 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UQ579 UT WOS:A1996UQ57900008 ER PT J AU Lillo, TM Plichta, MR Hackney, SA AF Lillo, TM Plichta, MR Hackney, SA TI Film thickness change due to grain boundary migration in stressed thin films at elevated temperatures SO SCRIPTA MATERIALIA LA English DT Article ID INSITU OBSERVATIONS; DISLOCATION-MOTION C1 MICHIGAN TECHNOL UNIV,DEPT MET & MAT ENGN,HOUGHTON,MI 49931. RP Lillo, TM (reprint author), IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. RI Lilllo, Thomas/S-5031-2016 OI Lilllo, Thomas/0000-0002-7572-7883 NR 13 TC 0 Z9 0 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUL 15 PY 1996 VL 35 IS 2 BP 233 EP 238 DI 10.1016/1359-6462(96)00112-1 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UQ579 UT WOS:A1996UQ57900016 ER PT J AU Mishra, RS Echer, C Bampton, CC Bieler, TR Mukherjee, AK AF Mishra, RS Echer, C Bampton, CC Bieler, TR Mukherjee, AK TI Influence of temperature on segregation in 2009 Al-SiCW composite and its implication on high strain rate superplasticity SO SCRIPTA MATERIALIA LA English DT Article ID METAL-MATRIX COMPOSITES; ALLOYS; INTERFACES C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720. ROCKWELL INT SCI CTR,THOUSAND OAKS,CA 91360. MICHIGAN STATE UNIV,DEPT MAT SCI & ENGN,E LANSING,MI 48824. RP Mishra, RS (reprint author), UNIV CALIF DAVIS,DEPT CHEM ENGN & MAT SCI,DAVIS,CA 95616, USA. RI Mishra, Rajiv/A-7985-2009 OI Mishra, Rajiv/0000-0002-1699-0614 NR 20 TC 14 Z9 14 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUL 15 PY 1996 VL 35 IS 2 BP 247 EP 252 DI 10.1016/1359-6462(96)00118-2 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UQ579 UT WOS:A1996UQ57900018 ER PT J AU Niu, H Houk, RS AF Niu, H Houk, RS TI Fundamental aspects of ion extraction in inductively coupled plasma mass spectrometry SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Review DE Campargue nozzle; electron density; electron temperature; ICP-MS; inductively coupled plasma mass spectrometry; ion deposition; ion extraction from plasmas; ion lens; Langmuir probe; plasma diagnostics; plasma source mass spectrometry; skimmer; space charge effects; supersonic beam; supersonic jet ID MICROWAVE-INDUCED PLASMA; ATOMIC EMISSION-SPECTROMETRY; ATMOSPHERIC-PRESSURE FLAMES; LANGMUIR PROBE MEASUREMENTS; ISOTOPE RATIO MEASUREMENTS; ENLARGED SAMPLING ORIFICE; AQUEOUS-SOLUTIONS; ICP-MS; IONIZATION SOURCE; CHARGE-TRANSFER AB The present understanding of the ion extraction process in inductively coupled plasma mass spectrometry (ICP-MS) is reviewed critically. Topics include ion production in the ICP, origins of polyatomic ions, causes of and remedies for the secondary discharge, properties of the supersonic jet and of the beam leaving the skimmer, space charge effects, and matrix interferences. Areas of recent interest are also described from the perspective of the ion extraction process. These recent topics include ''cool'' plasmas, the three-aperture interface, ion extraction from helium plasmas, and ion sampling considerations unique to magnetic sector, time-of-flight, and ion trap mass spectrometers. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,US DEPT ENERGY,AMES LAB,AMES,IA 50011. NR 236 TC 186 Z9 189 U1 6 U2 72 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD JUL 15 PY 1996 VL 51 IS 8 BP 779 EP 815 DI 10.1016/0584-8547(96)01506-6 PG 37 WC Spectroscopy SC Spectroscopy GA UX672 UT WOS:A1996UX67200002 ER PT J AU Gill, CG Garrett, AW Hemberger, PH Nogar, NS AF Gill, CG Garrett, AW Hemberger, PH Nogar, NS TI Selective laser ablation/ionization for ion trap mass spectrometry: Resonant laser ablation SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE ion trap mass spectrometry; laser ionization; multi-step ionization; resonant laser ablation ID DESORBED IONS; IONIZATION SPECTROSCOPY; DESORPTION; INJECTION AB Laser ablation provides a clean, broadly applicable ionization source for ion trap mass spectrometry. However, the ion storage capacity of an ion trap mass spectrometer requires a degree of selectivity in either the ion generation or ion storage process to allow effective interrogation of minority components. This can be accomplished by low-intensity irradiation of the sample with laser pulses tuned to a one- or two-photon resonant transition in the analyte of interest. Resonant laser ablation is a multistep process involving evaporation and subsequent ionization of a solid sample component of interest. The leading edge of a tunable laser pulse vaporizes near-surface material, which forms a plume directly above the sample. The trailing edge of the pulse preferentially excites, and subsequently ionizes, the component that is in resonance with the incident photons. In this manuscript, we report on the use of resonant laser ablation with an ion trap mass spectrometer for high sensitivity, high selectivity generation of analyte ions from a solid sample. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. NR 32 TC 27 Z9 28 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD JUL 15 PY 1996 VL 51 IS 8 BP 851 EP 862 DI 10.1016/0584-8547(96)01467-X PG 12 WC Spectroscopy SC Spectroscopy GA UX672 UT WOS:A1996UX67200006 ER PT J AU Browning, ND Pennycook, SJ AF Browning, ND Pennycook, SJ TI Direct experimental determination of the atomic structure at internal interfaces SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article; Proceedings Paper CT International Symposium on Atomic Bonding at Internal Interfaces - Modelling and Spectroscopy CY APR 24-28, 1995 CL SCHLOSS RINGBERG, GERMANY SP Deut Forschungsgemeinsch, Max Planck Gesell ID ELECTRON-ENERGY-LOSS; TILT GRAIN-BOUNDARIES; TRANSITION-METAL OXIDES; FIELD STEM IMAGES; LOSS SPECTROSCOPY; STRONTIUM-TITANATE; CRYSTAL-STRUCTURE; BARIUM-TITANATE; RESOLUTION; MICROSCOPY AB A crucial first step in understanding the effect that internal interfaces have on the properties of materials is the ability to determine the atomic structure at the interface. Because interfaces can contain atomic disorder, dislocations, segregated impurities and interphases, sensitivity to all of these features is essential for complete experimental characterization. By combining Z-contrast imaging and electron energy loss spectroscopy (EELS) in a dedicated scanning transmission electron microscope (STEM), the ability to probe the structure, bonding and composition at interfaces with the necessary atomic resolution has been obtained. Experimental conditions can be controlled to provide, simultaneously, both incoherent imaging and spectroscopy. This enables interface structures observed in the image to be interpreted intuitively and the bonding in a specified atomic column to be probed directly by EELS. The bonding and structure information can then be correlated using bond-valence sum analysis to produce structural models. This technique is demonstrated for 25 degrees, 36 degrees and 67 degrees symmetric and 45 degrees and 25 degrees asymmetric [001] tilt grain boundaries in SrTiO3. The structures of both types of boundary were found to contain partially occupied columns in the boundary plane. From these experimental results, a series of structural units were identified which could be combined, using continuity of grain boundary structure principles, to construct all [001] tilt boundaries in SrTiO3. Using these models, the ability of this technique to address the issues of vacancies and dopant segregation at grain boundaries in electroceramics is discussed. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Browning, ND (reprint author), UNIV ILLINOIS,DEPT PHYS MC273,845 W TAYLOR ST,CHICAGO,IL 60607, USA. OI Browning, Nigel/0000-0003-0491-251X NR 78 TC 84 Z9 84 U1 6 U2 37 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD JUL 14 PY 1996 VL 29 IS 7 BP 1779 EP 1798 DI 10.1088/0022-3727/29/7/013 PG 20 WC Physics, Applied SC Physics GA UZ485 UT WOS:A1996UZ48500013 ER PT J AU Durant, JL AF Durant, JL TI Evaluation of transition state properties by density functional theory SO CHEMICAL PHYSICS LETTERS LA English DT Article ID POTENTIAL-ENERGY SURFACE; NONLOCAL CORRECTIONS; GAUSSIAN-2 THEORY; REPRESENTATION; EXCHANGE AB We have evaluated the performance of five popular DFT functionals, BH&HLYP, B3PW91, B3P86, B3LYP and BLYP, in characterizing a set of seven 'well known' transition states. We found BH&HLYP performs best in calculating classical barrier heights, with the other functionals systematically underpredicting the barriers. All the functionals examined perform reasonably well in predicting geometries, and the BH&HLYP, B3PW91 and B3P86 functionals have similar performance in predicting vibrational frequencies. In examining the effect of basis set size we found essentially no systematic improvement in performance with increase in basis set size from 6-31G(d) to 6-311G(3df,2p). RP Durant, JL (reprint author), SANDIA NATL LABS, COMBUST RES FACIL, LIVERMORE, CA 94551 USA. NR 34 TC 247 Z9 247 U1 2 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUL 12 PY 1996 VL 256 IS 6 BP 595 EP 602 DI 10.1016/0009-2614(96)00478-2 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UX542 UT WOS:A1996UX54200006 ER PT J AU Frishman, AM Hoffman, DK Arnold, M Rakauskas, RJ Kouri, DJ AF Frishman, AM Hoffman, DK Arnold, M Rakauskas, RJ Kouri, DJ TI Distributed approximating functional approach to fitting and predicting potential surfaces .1. Atom-atom potentials (vol 252, pg 62, 1996) SO CHEMICAL PHYSICS LETTERS LA English DT Correction, Addition C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. UNIV ARKANSAS,DEPT MATH,FAYETTEVILLE,AR 72701. VILNIUS STATE UNIV,FAC PHYS,VILNIUS 2009,LITHUANIA. VILNIUS STATE UNIV,INST APPL SCI,VILNIUS 2009,LITHUANIA. UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204. UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. RP Frishman, AM (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011, USA. NR 1 TC 0 Z9 0 U1 1 U2 1 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 JUL 12 PY 1996 VL 256 IS 6 BP 684 EP 684 DI 10.1016/0009-2614(96)00572-6 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UX542 UT WOS:A1996UX54200021 ER PT J AU Cammack, JK Jalisatgi, S Matzger, AJ Negron, A Vollhardt, KPC AF Cammack, JK Jalisatgi, S Matzger, AJ Negron, A Vollhardt, KPC TI Room temperature CpCo-mediated cyclization of alpha,delta,omega-enediynes to rearranging strained tricylic dienes. Some observations of kinetic versus thermodynamic control SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID TRICYCLIC DIENES; COBALT; ENTRY; WALK C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RI Matzger, Adam/G-7497-2016 OI Matzger, Adam/0000-0002-4926-2752 NR 23 TC 36 Z9 36 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD JUL 12 PY 1996 VL 61 IS 14 BP 4798 EP 4800 DI 10.1021/jo960143x PG 3 WC Chemistry, Organic SC Chemistry GA UY940 UT WOS:A1996UY94000052 ER PT J AU Alexandratos, SD Trochimczuk, AW Horwitz, EP Gatrone, RC AF Alexandratos, SD Trochimczuk, AW Horwitz, EP Gatrone, RC TI Synthesis and characterization of a bifunctional ion exchange resin with polystyrene-immobilized diphosphonic acid ligands SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article ID METAL-IONS; DEPENDENCIES; COPPER AB A new ion exchange resin for the selective complexation of metal ions has been synthesized by functionalizing vinylbenzyl chloride-styrene-divinylbenzene copolymer beads with the sodium salt of tetra(isopropyl) methylene diphosphonate. The effects of bifunctionality, matrix rigidity, degree of functionalization, and macroporosity on final resin properties have been quantified. A sulfonic acid-diphosphonic acid bifunctional resin is highly selective with rapid complexation kinetics. A macroporous polymer matrix crosslinked with 10% divinylbenzene provides optimum results; for example, 99.7% Eu(III) is complexed from a IM nitric acid solution with a 30-min contact time. The importance of physical crosslinking as well as chemical crosslinking in limiting access of substrates into polymer-supported reagents is discussed. (C) 1996 John Wiley & Sons, Inc. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP Alexandratos, SD (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 18 TC 28 Z9 28 U1 2 U2 10 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD JUL 11 PY 1996 VL 61 IS 2 BP 273 EP 278 DI 10.1002/(SICI)1097-4628(19960711)61:2<273::AID-APP9>3.0.CO;2-M PG 6 WC Polymer Science SC Polymer Science GA UR697 UT WOS:A1996UR69700009 ER PT J AU Redfern, PC Horner, DA Curtiss, LA Gruen, DM AF Redfern, PC Horner, DA Curtiss, LA Gruen, DM TI Theoretical studies of growth of diamond (110) from dicarbon SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; H-ATOM ASSOCIATION; AB-INITIO; LOW-PRESSURE; MOLECULAR-DYNAMICS; SURFACE-REACTIONS; RATE CONSTANTS; FILM FORMATION; ACETYLENE; MECHANISM AB A mechanism for growth on the diamond (110) surface, with dicarbon (C-2) as the growth species, is examined. Reaction energies and activation energies-of the various steps in the mechanism were investigated on model systems using molecular quantum mechanics, including the AM1 semiempirical method and the BLYP/63 1G* density functional method. The BLYP/6-31G* method yielded reaction energies and activation barriers in reasonable agreement with the results of G2 theory on some simple, related reactions. Two models for a hydrogen-terminated diamond (110) surface were employed, one with 18 carbon atoms (C18H26) and another with 46 carbon atoms (C46H50) The results indicate that C-2 addition to diamond (110) is highly exothermic with small activation barriers (< 5 kcal/mol). Insertion of C-2 into CH bonds on the model surface to form an ethylene-like adsorbate is energetically favorable, resulting in energy lowerings of 150-180 kcal per mole of C-2. Formation of single bonds between adjacent adsorbed C-2 units can be initiated by the addition of a hydrogen atom to one of the adsorbed, ethylene-like C-2 moieties. The linking of two C-2 units by this process is exothermic. The formation of single bonds between adjacent adsorbed C-2 units can also occur directly, without initiation by hydrogen addition, and is exothermic for the linking of three or more C-2 units. By either pathway the formation of a C-C single bond on the surface is exothermic by 40-50 kcal/mol. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. N CENT COLL,NAPERVILLE,IL 60566. NR 50 TC 83 Z9 83 U1 1 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 11 PY 1996 VL 100 IS 28 BP 11654 EP 11663 DI 10.1021/jp953165g PG 10 WC Chemistry, Physical SC Chemistry GA UW685 UT WOS:A1996UW68500022 ER PT J AU Kemner, KM Hunter, DB Elam, WT Bertsch, PM AF Kemner, KM Hunter, DB Elam, WT Bertsch, PM TI XAFS studies of solution-phase complexes of cesium with dibenzo-18-crown-6 ethers SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ABSORPTION FINE-STRUCTURE; AQUEOUS-SOLUTIONS; CROWN-ETHERS; CHEMISTRY; POTASSIUM; SOLVENTS; SODIUM; SALTS; CS+ AB X-ray absorption fine structure (XAFS) measurements have been made at the Cs Lm absorption edge on (1) 0.04 M acetonitrile solutions with respect to both CsBr and dibenzo-18-crown-6 ether (Cs-D18C6), (2) solids produced by drying the aforementioned Cs-D18C6 solution complex, and (3) crystalline CsBr, CsCl, and CsF powders that were used as standards, XAFS measurements have also been made at the Br M absorption edge on the same 0.04 M solution mentioned above. Due to the many difficulties associated with obtaining high-quality XAFS data on these systems, a custom-manufactured 5-mil-thick Sc foil was used in conjunction with a Seller slit assembly to improve the XAFS signal-to-noise ratio by almost a factor of 6, XAFS analyses of the Cs-D18C6 solution show the presence of a 1:1 Cs-D18C6 complex with a Br contact ion, consistent with previous references derived from Cs-133 nuclear magnetic resonance investigations. For interpretation of the Cs LIII edge data, the choice of a Br counterion reduces the error in determining the presence of a single counterion among the lighter backscattering O and C atoms of the crown ether complex. Observation of the normalized XAFS data for the dried Cs-crown ether solution shows that the Cs atom's local environment changes from a 1:1 Cs-D18C6 complex to a predominantly crystalline CsBr solid phase. This recrystallization during drying illustrates the importance of in situ methods to characterize chemical speciation in solution. The ability of XAFS to directly probe the ternary Cs-D18C6-Br contact ion pair opens many exciting avenues for improving extraction methodologies. C1 USN,RES LAB,WASHINGTON,DC 20375. UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,DIV BIOGEOCHEM,AIKEN,SC 29802. NR 25 TC 15 Z9 15 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 11 PY 1996 VL 100 IS 28 BP 11698 EP 11703 DI 10.1021/jp9604608 PG 6 WC Chemistry, Physical SC Chemistry GA UW685 UT WOS:A1996UW68500028 ER PT J AU Taylor, RS Dang, LX Garrett, BC AF Taylor, RS Dang, LX Garrett, BC TI Molecular dynamics simulations of the liquid/vapor interface of SPC/E water SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID EFFECTIVE PAIR POTENTIALS; X-RAY REFLECTIVITY; VAPOR INTERFACE; THERMODYNAMIC PROPERTIES; ORIENTATIONAL STRUCTURE; SURFACE-TENSION; EQUILIBRIUM; LIQUIDS; MODEL AB Molecular dynamics computer simulations have been used to explore the structural and-dynamical properties of water's liquid/vapor interface using the simple extended point charge (SPC/E) model. Comparisons to the existing experimental and simulation data suggest that the SPC/E potential energy function provides a semiquantitative description of this interface. The orientation of H2O molecules at the interface is found to be bimodal in nature. The self-diffusion constant of water is calculated to be larger at the surface than in the bulk. C1 PACIFIC NW NATL LAB,ENVIRONM MOL SCI LAB,RICHLAND,WA 99352. RI Garrett, Bruce/F-8516-2011 NR 46 TC 196 Z9 197 U1 5 U2 26 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JUL 11 PY 1996 VL 100 IS 28 BP 11720 EP 11725 DI 10.1021/jp960615b PG 6 WC Chemistry, Physical SC Chemistry GA UW685 UT WOS:A1996UW68500031 ER PT J AU Minty, MG Siemann, RH AF Minty, MG Siemann, RH TI Heavy beam loading in storage ring radio frequency systems SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Effects arising from both steady-state and transient beam loading of an rf system in circular accelerators are described. The stability of the rf system and the particle beam is studied using a numerical model of the beam-cavity interaction with multiple feedback loops. Nonlinearities in the power source are also considered. As a special case, a detailed model of the Stanford Linear Collider damping rings is presented. The effects of beam-induced transients and intensity jitter on the rf system are analyzed and are used to determine stability tolerances for incoming current variations. A low current limit is demonstrated and techniques are described to ease this limit. Implications for the design and operation of future storage ring rf systems are studied in the heavily beam-loaded limit. RP Minty, MG (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 10 TC 3 Z9 7 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 JUL 11 PY 1996 VL 376 IS 3 BP 301 EP 318 DI 10.1016/0168-9002(96)00180-5 PG 18 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA UY058 UT WOS:A1996UY05800001 ER EF